Cardio-oncology Related to Heart Failure: Epidermal Growth Factor Receptor Target-Based Therapy.

PubMed

Kenigsberg, Benjamin; Jain, Varun; Barac, Ana

2017-04-01

Cancer therapy targeting the epidermal growth factor receptor (EGFR)/erythroblastic leukemia viral oncogene B (ErbB)/human EGFR receptor (HER) family of tyrosine kinases has been successfully used in treatment of several malignancies. The ErbB pathways play a role in the maintenance of cardiac homeostasis. This article summarizes current knowledge about EGFR/ErbB/HER receptor-targeted cancer therapeutics focusing on their cardiotoxicity profiles, molecular mechanisms, and implications in clinical cardio-oncology. The article discusses challenges in predicting, monitoring, and treating cardiac dysfunction and heart failure associated with ErbB-targeted cancer therapeutics and highlights opportunities for researchers and clinical investigators. Copyright © 2016 Elsevier Inc. All rights reserved.

Fabrication of an ultrafine fish gelatin nanofibrous web from an aqueous solution by electrospinning.

PubMed

Kwak, Hyo Won; Shin, Munju; Lee, Jeong Yun; Yun, Haesung; Song, Dae Woong; Yang, Yesol; Shin, Bong-Seob; Park, Young Hwan; Lee, Ki Hoon

2017-09-01

Electrospinning of aqueous gelatin solution obtained from bovine or porcine sources has been difficult to achieve without additional facilities, such as a temperature control oven or heating cover. Gelatin from cold-water fish has low contents of proline (Pro) and hydroxyproline (Hyp) compared with mammalian-derived gelatin. For this reason, the fish-derived gelatin maintains a sol state without showing gelation behavior at room temperature. In the present study, we prepared an ultrafine fish gelatin nanofibrous web by electrospinning from aqueous solutions without any additive polymers or temperature control facilities. The concentration and viscosity of fish gelatin are the most important factor in determining the electrospinnability and fiber diameter. Electrospinning of aqueous fish gelatin has the highest nanofiber productivity compared to other organic solvent systems. Using glutaraldehyde vapor (GTA), the water stability was improved and substantial enhancement was achieved in the mechanical properties. Finally, the cytotoxicity of a fish gelatin nanofibrous scaffold was evaluated based on a cell proliferation study by culturing human dermal fibroblasts (HDFs) compared with a fish gelatin film and nanofibrous mat from mammalian gelatin. The result shows better initial cell attachment and proliferation compared with the fish gelatin film and no significant difference compared with mammalian-derived gelatin nanofibrous mat. We expect that electrospinning of aqueous fish gelatin could be an effective alternative mammalian gelatin source. Copyright © 2017 Elsevier B.V. All rights reserved.

IGF system targeted therapy: Therapeutic opportunities for ovarian cancer.

PubMed

Liefers-Visser, J A L; Meijering, R A M; Reyners, A K L; van der Zee, A G J; de Jong, S

2017-11-01

The insulin-like growth factor (IGF) system comprises multiple growth factor receptors, including insulin-like growth factor 1 receptor (IGF-1R), insulin receptor (IR) -A and -B. These receptors are activated upon binding to their respective growth factor ligands, IGF-I, IGF-II and insulin, and play an important role in development, maintenance, progression, survival and chemotherapeutic response of ovarian cancer. In many pre-clinical studies anti-IGF-1R/IR targeted strategies proved effective in reducing growth of ovarian cancer models. In addition, anti-IGF-1R targeted strategies potentiated the efficacy of platinum based chemotherapy. Despite the vast amount of encouraging and promising pre-clinical data, anti-IGF-1R/IR targeted strategies lacked efficacy in the clinic. The question is whether targeting the IGF-1R/IR signaling pathway still holds therapeutic potential. In this review we address the complexity of the IGF-1R/IR signaling pathway, including receptor heterodimerization within and outside the IGF system and downstream signaling. Further, we discuss the implications of this complexity on current targeted strategies and indicate therapeutic opportunities for successful targeting of the IGF-1R/IR signaling pathway in ovarian cancer. Multiple-targeted approaches circumventing bidirectional receptor tyrosine kinase (RTK) compensation and prevention of system rewiring are expected to have more therapeutic potential. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Transcriptome Analysis of Gelatin Seed Treatment as a Biostimulant of Cucumber Plant Growth

PubMed Central

Wilson, H. T.; Xu, K.; Taylor, A. G.

2015-01-01

The beneficial effects of gelatin capsule seed treatment on enhanced plant growth and tolerance to abiotic stress have been reported in a number of crops, but the molecular mechanisms underlying such effects are poorly understood. Using mRNA sequencing based approach, transcriptomes of one- and two-week-old cucumber plants from gelatin capsule treated and nontreated seeds were characterized. The gelatin treated plants had greater total leaf area, fresh weight, frozen weight, and nitrogen content. Pairwise comparisons of the RNA-seq data identified 620 differentially expressed genes between treated and control two-week-old plants, consistent with the timing when the growth related measurements also showed the largest differences. Using weighted gene coexpression network analysis, significant coexpression gene network module of 208 of the 620 differentially expressed genes was identified, which included 16 hub genes in the blue module, a NAC transcription factor, a MYB transcription factor, an amino acid transporter, an ammonium transporter, a xenobiotic detoxifier-glutathione S-transferase, and others. Based on the putative functions of these genes, the identification of the significant WGCNA module and the hub genes provided important insights into the molecular mechanisms of gelatin seed treatment as a biostimulant to enhance plant growth. PMID:26558288

Gelatin Nanoparticles with Enhanced Affinity for Calcium Phosphate.

PubMed

Farbod, Kambiz; Diba, Mani; Zinkevich, Tatiana; Schmidt, Stephan; Harrington, Matthew J; Kentgens, Arno P M; Leeuwenburgh, Sander C G

2016-05-01

Gelatin nanoparticles can be tuned with respect to their drug loading efficiency, degradation rate, and release kinetics, which renders these drug carriers highly suitable for a wide variety of biomedical applications. The ease of functionalization has rendered gelatin an interesting candidate material to introduce specific motifs for selective targeting to specific organs, but gelatin nanoparticles have not yet been modified to increase their affinity to mineralized tissue. By means of conjugating bone-targeting alendronate to biocompatible gelatin nanoparticles, a simple method is developed for the preparation of gelatin nanoparticles which exhibit strong affinity to mineralized surfaces. It has been shown that the degree of alendronate functionalization can be tuned by controlling the glutaraldehyde crosslinking density, the molar ratio between alendronate and glutaraldehyde, as well as the pH of the conjugation reaction. Moreover, it has been shown that the affinity of gelatin nanoparticles to calcium phosphate increases considerably upon functionalization with alendronate. In summary, gelatin nanoparticles have been developed, which exhibit great potential for use in bone-specific drug delivery and regenerative medicine. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Breast Cancer: Current Molecular Therapeutic Targets and New Players.

PubMed

Nagini, Siddavaram

2017-01-01

Breast cancer is the most common cancer and the most frequent cause of cancer death among women worldwide. Breast cancer is a complex, heterogeneous disease classified into hormone-receptor-positive, human epidermal growth factor receptor-2 overexpressing (HER2+) and triple-negative breast cancer (TNBC) based on histological features. Endocrine therapy, the mainstay of treatment for hormone-responsive breast cancer involves use of selective estrogen receptor modulators (SERMs), selective estrogen receptor downregulators (SERDs) and aromatase inhibitors (AIs). Agents that target estrogen receptor (ER) and HER2 such as tamoxifen and trastuzumab have been the most extensively used therapeutics for breast cancer. Crosstalk between ER and other signalling networks as well as epigenetic mechanisms have been envisaged to contribute to endocrine therapy resistance. TNBC, a complex, heterogeneous, aggressive form of breast cancer in which the cells do not express ER, progesterone receptor or HER2 is refractory to therapy. Several molecular targets are being explored to target TNBC including androgen receptor, epidermal growth factor receptor (EGFR), poly(ADP-ribose) polymerase (PARP), and vascular endothelial growth factor (VEGF). Receptors, protein tyrosine kinases, phosphatases, proteases, PI3K/Akt signalling pathway, microRNAs (miRs) and long noncoding RNAs (lncRNAs) are potential therapeutic targets. miR-based therapeutic approaches include inhibition of oncomiRs by antisense oligonucleotides, restoration of tumour suppressors using miR mimics, and chemical modification of miRs. The lnRNAs HOTAIR, SPRY4-IT1, GAS5, and PANDAR, new players in tumour development and prognosis may have theranostic applications in breast cancer. Several novel classes of mechanism-based drugs have been designed and synthesised for treatment of breast cancer. Integration of nucleic acid sequencing studies with mass spectrometry-based peptide sequencing and posttranslational modifications as well as rational drug design will provide a more comprehensive understanding of the pathophysiology of breast cancer and help in evolving therapeutic strategies.

Endogenous production of fibronectin is required for self-renewal of cultured mouse embryonic stem cells

PubMed Central

Hunt, Geoffrey C.; Singh, Purva; Schwarzbauer, Jean E.

2012-01-01

Pluripotent cells are attached to the extracellular matrix (ECM) as they make cell fate decisions within the stem cell niche. Here we show that the ubiquitous ECM protein fibronectin is required for self-renewal decisions by cultured mouse embryonic stem (mES) cells. Undifferentiated mES cells produce fibronectin and assemble a fibrillar matrix. Increasing the level of substrate fibronectin increased cell spreading and integrin receptor signaling through focal adhesion kinase, while concomitantly inducing the loss of Nanog and Oct4 self-renewal markers. Conversely, reducing fibronectin production by mES cells growing on a feeder-free gelatin substrate caused loss of cell adhesion, decreased integrin signaling, and decreased expression of self-renewal markers. These effects were reversed by providing the cells with exogenous fibronectin, thereby restoring adhesion to the gelatin substrate. Interestingly, mES cells do not adhere directly to the gelatin substrate, but rather adhere indirectly through gelatin-bound fibronectin, which facilitates self-renewal via its effects on cell adhesion. These results provide new insights into the mechanism of regulation of self-renewal by growth on a gelatin-coated surface. The effects of increasing or decreasing fibronectin levels show that self-renewal depends on an intermediate level of cell-fibronectin interactions. By providing cell adhesive signals that can act with other self-renewal factors to maintain mES cell pluripotency, fibronectin is therefore a necessary component of the self-renewal signaling pathway in culture. PMID:22710062

Endogenous production of fibronectin is required for self-renewal of cultured mouse embryonic stem cells.

PubMed

Hunt, Geoffrey C; Singh, Purva; Schwarzbauer, Jean E

2012-09-10

Pluripotent cells are attached to the extracellular matrix (ECM) as they make cell fate decisions within the stem cell niche. Here we show that the ubiquitous ECM protein fibronectin is required for self-renewal decisions by cultured mouse embryonic stem (mES) cells. Undifferentiated mES cells produce fibronectin and assemble a fibrillar matrix. Increasing the level of substrate fibronectin increased cell spreading and integrin receptor signaling through focal adhesion kinase, while concomitantly inducing the loss of Nanog and Oct4 self-renewal markers. Conversely, reducing fibronectin production by mES cells growing on a feeder-free gelatin substrate caused loss of cell adhesion, decreased integrin signaling, and decreased expression of self-renewal markers. These effects were reversed by providing the cells with exogenous fibronectin, thereby restoring adhesion to the gelatin substrate. Interestingly, mES cells do not adhere directly to the gelatin substrate, but rather adhere indirectly through gelatin-bound fibronectin, which facilitates self-renewal via its effects on cell adhesion. These results provide new insights into the mechanism of regulation of self-renewal by growth on a gelatin-coated surface. The effects of increasing or decreasing fibronectin levels show that self-renewal depends on an intermediate level of cell-fibronectin interactions. By providing cell adhesive signals that can act with other self-renewal factors to maintain mES cell pluripotency, fibronectin is therefore a necessary component of the self-renewal signaling pathway in culture. Copyright © 2012 Elsevier Inc. All rights reserved.

Needle Steering in Biological Tissue using Ultrasound-based Online Curvature Estimation

PubMed Central

Moreira, Pedro; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

2014-01-01

Percutaneous needle insertions are commonly performed for diagnostic and therapeutic purposes. Accurate placement of the needle tip is important to the success of many needle procedures. The current needle steering systems depend on needle-tissue-specific data, such as maximum curvature, that is unavailable prior to an interventional procedure. In this paper, we present a novel three-dimensional adaptive steering method for flexible bevel-tipped needles that is capable of performing accurate tip placement without previous knowledge about needle curvature. The method steers the needle by integrating duty-cycled needle steering, online curvature estimation, ultrasound-based needle tracking, and sampling-based motion planning. The needle curvature estimation is performed online and used to adapt the path and duty cycling. We evaluated the method using experiments in a homogenous gelatin phantom, a two-layer gelatin phantom, and a biological tissue phantom composed of a gelatin layer and in vitro chicken tissue. In all experiments, virtual obstacles and targets move in order to represent the disturbances that might occur due to tissue deformation and physiological processes. The average targeting error using our new adaptive method is 40% lower than using the conventional non-adaptive duty-cycled needle steering method. PMID:26229729

Combination therapy of potential gene to enhance oral cancer therapeutic effect

NASA Astrophysics Data System (ADS)

Yeh, Chia-Hsien; Hsu, Yih-Chih

2015-03-01

The epidermal growth factor receptor (EGFR) over-regulation related to uncontrolled cell division and promotes progression in tumor. Over-expression of human epidermal growth factor receptor (EGFR) has been detected in oral cancer cells. EGFR-targeting agents are potential therapeutic modalities for treating oral cancer based on our in vitro study. Liposome nanotechnology is used to encapsulate siRNA and were modified with target ligand to receptors on the surface of tumor cells. We used EGFR siRNA to treat oral cancer in vitro.

Comparison of ballistic impact effects between biological tissue and gelatin.

PubMed

Jin, Yongxi; Mai, Ruimin; Wu, Cheng; Han, Ruiguo; Li, Bingcang

2018-02-01

Gelatin is commonly used in ballistic testing as substitute for biological tissue. Comparison of ballistic impact effects produced in the gelatin and living tissue is lacking. The work in this paper was aimed to compare the typical ballistic impact effects (penetration trajectory, energy transfer, temporary cavity) caused by 4.8mm steel ball penetrating the 60kg porcine hind limbs and 10wt% gelatin. The impact event in the biological tissue was recorded by high speed flash X-ray machine at different delay time, while the event in the gelatin continuously recorded by high speed video was compared to that in the biological tissue. The collected results clearly displayed that the ballistic impact effects in the muscle and gelatin were similar for the steel ball test; as for instance, the projectile trajectory in the two targets was basically similar, the process of energy transfer was highly coincident, and the expansion of temporary cavity followed the same pattern. This study fully demonstrated that choosing gelatin as muscle simulant was reasonable. However, the maximum temporary cavity diameter in the gelatin was a little larger than that in the muscle, and the expansion period of temporary cavity was longer in the gelatin. Additionally, the temporary cavity collapse process in the two targets followed different patterns, and the collapse period in the gelatin was two times as long as that in the muscle. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cosilencing Intestinal Transglutaminase-2 and Interleukin-15 Using Gelatin-Based Nanoparticles in an in Vitro Model of Celiac Disease.

PubMed

Attarwala, Husain; Clausen, Valerie; Chaturvedi, Prasoon; Amiji, Mansoor M

2017-09-05

In this study, we have developed a type B gelatin nanoparticle based siRNA delivery system for silencing of intestinal transglutaminase-2 (TG2) and interleukin-15 (IL-15) genes in cultured human intestinal epithelial cells (Caco-2) and murine alveolar macrophage cells (J774A.1). Small interfering RNA (siRNA) targeting the TG2 or IL-15 gene was encapsulated within gelatin nanoparticles using ethanol-water solvent displacement method. Size, charge, and morphology of gelatin nanoparticles were evaluated using a Zetasizer instrument and transmission electron microscopy. siRNA encapsulation efficiency was determined using an siRNA specific stem-loop quantitative polymerase chain reaction (qPCR) assay. Cellular uptake of siRNA-containing gelatin nanoparticles was determined using fluorescent microscopy and stem-loop qPCR assay. siRNA loading in the RISC (RNA-induced silencing complex) was determined by immunoprecipitation of argonaute 2 (AGO2) protein followed by stem-loop qPCR for siRNA quantification. Gene expression analysis of TG2, IL-15, and the proinflammatory cytokines, tumor necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ), was performed using qPCR assays. Efficacy of silencing TG2 and IL-15 knockdown was evaluated in an in vitro model of celiac disease by utilizing immunogenic α-gliadin peptide p31-43 in cultured J774A.1 cells. siRNA-containing gelatin nanoparticles were spherical in shape with mean particle size and charge of 217 ± 8.39 nm and -6.2 ± 0.95 mV, respectively. siRNA loading efficiency within gelatin nanoparticles was found to be 89.3 ± 3.05%. Evaluations of cellular uptake using fluorescent microscopy showed rapid internalization of gelatin nanoparticles within 2 h of dosing, with cytosolic localization of delivered siRNA in Caco-2 cells. Gelatin nanoparticles showed greater intracellular siRNA exposure with a longer half-life, when compared to Lipofectamine-mediated siRNA delivery. Approximately 0.1% of total intracellular siRNA was associated in the RISC complex. A maximum knockdown of 60% was observed at 72 h post siRNA treatment for both TG2 and IL-15 genes, which corresponded to ∼200 copies of RISC associated siRNA. Further, efficacy of gelatin nanoparticle mediated knockdown of TG2 and IL-15 mRNA was tested in an in vitro model of celiac disease. Significant suppression in the levels of proinflammatory cytokines (TNF-α and IFN-γ) was observed in p31-43 stimulated J774A.1 cells upon either IL-15 or IL-15 + TG2 siRNA treatment. The results from this study indicate that gelatin nanoparticle mediated TG2 and IL-15 siRNA gene silencing is a very promising approach for the treatment of celiac disease.

Active radar guides missile to its target: receptor-based targeted treatment of hepatocellular carcinoma by nanoparticulate systems.

PubMed

Yan, Jing-Jun; Liao, Jia-Zhi; Lin, Ju-Sheng; He, Xing-Xing

2015-01-01

Patients with hepatocellular carcinoma (HCC) usually present at advanced stages and do not benefit from surgical resection, so drug therapy should deserve a prominent place in unresectable HCC treatment. But chemotherapy agents, such as doxorubicin, cisplatin, and paclitaxel, frequently encounter important problems such as low specificity and non-selective biodistribution. Recently, the development of nanotechnology led to significant breakthroughs to overcome these problems. Decorating the surfaces of nanoparticulate-based drug carriers with homing devices has demonstrated its potential in concentrating chemotherapy agents specifically to HCC cells. In this paper, we reviewed the current status of active targeting strategies for nanoparticulate systems based on various receptors such as asialoglycoprotein receptor, transferrin receptor, epidermal growth factor receptor, folate receptor, integrin, and CD44, which are abundantly expressed on the surfaces of hepatocytes or liver cancer cells. Furthermore, we pointed out their merits and defects and provided theoretical references for further research.

Gelatin-based laser direct-write technique for the precise spatial patterning of cells.

PubMed

Schiele, Nathan R; Chrisey, Douglas B; Corr, David T

2011-03-01

Laser direct-writing provides a method to pattern living cells in vitro, to study various cell-cell interactions, and to build cellular constructs. However, the materials typically used may limit its long-term application. By utilizing gelatin coatings on the print ribbon and growth surface, we developed a new approach for laser cell printing that overcomes the limitations of Matrigel™. Gelatin is free of growth factors and extraneous matrix components that may interfere with cellular processes under investigation. Gelatin-based laser direct-write was able to successfully pattern human dermal fibroblasts with high post-transfer viability (91% ± 3%) and no observed double-strand DNA damage. As seen with atomic force microscopy, gelatin offers a unique benefit in that it is present temporarily to allow cell transfer, but melts and is removed with incubation to reveal the desired application-specific growth surface. This provides unobstructed cellular growth after printing. Monitoring cell location after transfer, we show that melting and removal of gelatin does not affect cellular placement; cells maintained registry within 5.6 ± 2.5 μm to the initial pattern. This study demonstrates the effectiveness of gelatin in laser direct-writing to create spatially precise cell patterns with the potential for applications in tissue engineering, stem cell, and cancer research.

Ultrasound-guided three-dimensional needle steering in biological tissue with curved surfaces

PubMed Central

Abayazid, Momen; Moreira, Pedro; Shahriari, Navid; Patil, Sachin; Alterovitz, Ron; Misra, Sarthak

2015-01-01

In this paper, we present a system capable of automatically steering a bevel-tipped flexible needle under ultrasound guidance toward a physical target while avoiding a physical obstacle embedded in gelatin phantoms and biological tissue with curved surfaces. An ultrasound pre-operative scan is performed for three-dimensional (3D) target localization and shape reconstruction. A controller based on implicit force control is developed to align the transducer with curved surfaces to assure the maximum contact area, and thus obtain an image of sufficient quality. We experimentally investigate the effect of needle insertion system parameters such as insertion speed, needle diameter and bevel angle on target motion to adjust the parameters that minimize the target motion during insertion. A fast sampling-based path planner is used to compute and periodically update a feasible path to the target that avoids obstacles. We present experimental results for target reconstruction and needle insertion procedures in gelatin-based phantoms and biological tissue. Mean targeting errors of 1.46 ± 0.37 mm, 1.29 ± 0.29 mm and 1.82 ± 0.58 mm are obtained for phantoms with inclined, curved and combined (inclined and curved) surfaces, respectively, for insertion distance of 86–103 mm. The achieved targeting errors suggest that our approach is sufficient for targeting lesions of 3 mm radius that can be detected using clinical ultrasound imaging systems. PMID:25455165

Examination of contrast mechanisms in optoacoustic imaging of thermal lesions

NASA Astrophysics Data System (ADS)

Richter, Christian; Spirou, Gloria; Oraevsky, Alexander A.; Whelan, William M.; Kolios, Michael C.

2006-02-01

Optoacoustic Imaging is based on the thermal expansion of tissue caused by a temperature rise due to absorption of short laser pulses. At constant laser fluence, optoacoustic image contrast is proportional to differences in optical absorption and the thermoacoustic efficiency, expressed by the Grueuneisen parameter, Γ. Γ is proportional to the thermal expansion coefficient, the sound velocity squared and the inverse heat capacity at constant pressure. In thermal therapies, these parameters may be modified in the treated area. In this work experiments were performed to examine the influence of these parameters on image contrast. A Laser Optoacoustic Imaging System (LOIS, Fairway Medical Technologies, Houston, Texas) was used to image tissue phantoms comprised of cylindrical Polyvinyl Chloride Plastisol (PVCP) optical absorbing targets imbedded in either gelatin or PVCP as the background medium. Varying concentrations of Black Plastic Color (BPC) and titanium dioxide (TiO II) were added to targets and background to yield desired tissue relevant optical absorption and effective scattering coefficients, respectively. In thermal therapy experiments, ex-vivo bovine liver was heated with laser fibres (805nm laser at 5 W for 600s) to create regions of tissue coagulation. Lesions formed in the liver tissue were visible using the LOIS system with reasonable correspondence to the actual region of tissue coagulation. In the phantom experiments, contrast could be seen with low optical absorbing targets (μ a of 0.50cm -1 down to 0.13cm-1) embedded in a gelatin background (see manuscript for formula). Therefore, the data suggest that small objects (< 5mm) with low absorption coefficients (in the range < 1cm -1) can be imaged using LOIS. PVCP-targets in gelatin were visible, even with the same optical properties as the gelatin, but different Γ. The enhanced contrast may also be caused by differences in the mechanical properties between the target and the surrounding medium. PVCP-targets imbedded in PVCP produced poorer image contrast than PVCP-targets in gelatin with comparable optical properties. The preliminary investigation in tissue equivalent phantoms indicates that in addition to tissue optical properties, differences in mechanical properties between heated and unheated tissues may be responsible for image contrast. Furthermore, thermal lesions in liver tissue, ex-vivo, can be visualized using an optoacoustic system.

Development of novel sibutramine base-loaded solid dispersion with gelatin and HPMC: physicochemical characterization and pharmacokinetics in beagle dogs.

PubMed

Lim, Hyun-Tae; Balakrishnan, Prabagar; Oh, Dong Hoon; Joe, Kwan Hyung; Kim, Young Ran; Hwang, Doo Hyung; Lee, Yong-Bok; Yong, Chul Soon; Choi, Han-Gon

2010-09-15

To develop a novel sibutramine base-loaded solid dispersion with enhanced solubility and bioavailability, various solid dispersions were prepared using a spray drying technique with hydrophilic polymers such as gelatin, HPMC and citric acid. Their solubility, thermal characteristics and crystallinity were investigated. The dissolution and pharmacokinetics of the sibutramine base-loaded solid dispersion were then compared with a sibutramine hydrochloride monohydrate-loaded commercial product (Reductil). The solid dispersions prepared with gelatin gave higher drug solubility than those prepared without gelatin, irrespective of the amount of polymer. The sibutramine base-loaded solid dispersions containing hydrophilic polymer and citric acid showed higher drug solubility compared to sibutramine base and sibutramine hydrochloride monohydrate. Among the formulations tested, the solid dispersion composed of sibutramine base/gelatin/HPMC/citric acid at the weight ratio of 1/0.8/0.2/0.5 gave the highest solubility of 5.03+/-0.24 mg/ml. Our DSC and powder X-ray diffraction results showed that the drug was present in an altered amorphous form in this solid dispersion. The difference factor (f(1)) values between solid dispersion and commercial product were 2.82, 6.65 and 6.31 at pH 1.2, 4.0 and 6.8, respectively. Furthermore, they had the similarity factor (f(2)) value of 65.68, 53.43 and 58.97 at pH 1.2, 4.0 and 6.8, respectively. Our results suggested that the solid dispersion and commercial product produced a similar correlation of dissolution profiles at all pH ranges. The AUC, C(max) and T(max) of the parent drug and metabolite I and II from the solid dispersion were not significantly different from those of the commercial product, suggesting that the solid dispersion might be bioequivalent to the commercial product in beagle dogs. Thus, the sibutramine base-loaded solid dispersion prepared with gelatin, HPMC and citric acid is a promising candidate for improving the solubility and bioavailability of the poorly water-soluble sibutramine base. Crown Copyright 2010. Published by Elsevier B.V. All rights reserved.

Safe administration of a gelatin-containing vaccine in an adult with galactose-α-1,3-galactose allergy.

PubMed

Pinson, Michelle L; Waibel, Kirk H

2015-03-03

Immunoglobulin (Ig) E antibodies to galactose-α-1,3-galactose (α-Gal) are associated with delayed anaphylaxis to mammalian food products and gelatin-based foods (Commins et al., J Allergy Clin Immunol 2009;123:426; Caponetto et al., J Allergy Clin Immunol Pract 2013;1:302). We describe a patient with α-Gal allergy who successfully tolerated the live zoster vaccine and we review anaphylactic reactions reported to this vaccine. Our patient, who tolerated a vaccine containing the highest gelatin content, is reassuring but continued safety assessment of gelatin-containing vaccines for this patient cohort is recommended as there are multiple factors for this patient cohort that influence the reaction risk. Published by Elsevier Ltd.

Tyrosine kinase inhibitor induced growth factor receptor upregulation enhances the efficacy of near-infrared targeted photodynamic therapy in esophageal adenocarcinoma cell lines.

PubMed

Hartmans, Elmire; Linssen, Matthijs D; Sikkens, Claire; Levens, Afra; Witjes, Max J H; van Dam, Gooitzen M; Nagengast, Wouter B

2017-05-02

Esophageal carcinoma (EC) is a global health problem, with disappointing 5-year survival rates of only 15-25%. Near-infrared targeted photodynamic therapy (NIR-tPDT) is a novel strategy in which cancer-targeted phototoxicity is able to selectively treat malignant cells. In this in vitro report we demonstrate the applicability of antibody-based NIR-tPDT in esophageal adenocarcinoma (EAC), using the phototoxic compounds cetuximab-IRDye700DX and trastuzumab-IRDye700DX, targeting respectively epidermal growth factor receptor 1 (EGFR) and 2 (HER2). Furthermore, we demonstrate that NIR-tPDT can be made more effective by tyrosine kinase inhibitor (TKI) induced growth receptor upregulation. Together, these results unveil a novel strategy for non-invasive EAC treatment, and by pretreatment-induced receptor upregulation its future clinical application may be optimized.

Gelatin-Based Laser Direct-Write Technique for the Precise Spatial Patterning of Cells

PubMed Central

Schiele, Nathan R.; Chrisey, Douglas B.

2011-01-01

Laser direct-writing provides a method to pattern living cells in vitro, to study various cell–cell interactions, and to build cellular constructs. However, the materials typically used may limit its long-term application. By utilizing gelatin coatings on the print ribbon and growth surface, we developed a new approach for laser cell printing that overcomes the limitations of Matrigel™. Gelatin is free of growth factors and extraneous matrix components that may interfere with cellular processes under investigation. Gelatin-based laser direct-write was able to successfully pattern human dermal fibroblasts with high post-transfer viability (91% ± 3%) and no observed double-strand DNA damage. As seen with atomic force microscopy, gelatin offers a unique benefit in that it is present temporarily to allow cell transfer, but melts and is removed with incubation to reveal the desired application-specific growth surface. This provides unobstructed cellular growth after printing. Monitoring cell location after transfer, we show that melting and removal of gelatin does not affect cellular placement; cells maintained registry within 5.6 ± 2.5 μm to the initial pattern. This study demonstrates the effectiveness of gelatin in laser direct-writing to create spatially precise cell patterns with the potential for applications in tissue engineering, stem cell, and cancer research. PMID:20849381

Enzymatic regulation of functional vascular networks using gelatin hydrogels

PubMed Central

Chuang, Chia-Hui; Lin, Ruei-Zeng; Tien, Han-Wen; Chu, Ya-Chun; Li, Yen-Cheng; Melero-Martin, Juan M.; Chen, Ying-Chieh

2015-01-01

To manufacture tissue engineering-based functional tissues, scaffold materials that can be sufficiently vascularized to mimic the functionality and complexity of native tissues are needed. Currently, vascular network bioengineering is largely carried out using natural hydrogels as embedding scaffolds, but most natural hydrogels have poor mechanical stability and durability, factors that critically limit their widespread use. In this study, we examined the suitability of gelatin-phenolic hydroxyl (gelatin-Ph) hydrogels that can be enzymatically crosslinked, allowing tuning of the storage modulus and the proteolytic degradation rate, for use as injectable hydrogels to support the human progenitor cell-based formation of a stable and mature vascular network. Porcine gelatin-Ph hydrogels were found to be cytocompatible with human blood-derived endothelial colony-forming cells and white adipose tissue-derived mesenchymal stem cells, resulting in >87% viability, and cell proliferation and spreading could be modulated by using hydrogels with different proteolytic degradability and stiffness. In addition, gelatin was extracted from mouse dermis and murine gelatin-Ph hydrogels were prepared. Importantly, implantation of human cell-laden porcine or murine gelatin-Ph hydrogels into immunodeficient mice resulted in the rapid formation of functional anastomoses between the bioengineered human vascular network and the mouse vasculature. Furthermore, the degree of enzymatic crosslinking of the gelatin-Ph hydrogels could be used to modulate cell behavior and the extent of vascular network formation in vivo. Our report details a technique for the synthesis of gelatin-Ph hydrogels from allogeneic or xenogeneic dermal skin and suggests that these hydrogels can be used for biomedical applications that require the formation of microvascular networks, including the development of complex engineered tissues. PMID:25749296

Gelatin- and starch-based hydrogels. Part A: Hydrogel development, characterization and coating.

PubMed

Van Nieuwenhove, Ine; Salamon, Achim; Peters, Kirsten; Graulus, Geert-Jan; Martins, José C; Frankel, Daniel; Kersemans, Ken; De Vos, Filip; Van Vlierberghe, Sandra; Dubruel, Peter

2016-11-05

The present work aims at constructing the ideal scaffold matrix of which the physico-chemical properties can be altered according to the targeted tissue regeneration application. Ideally, this scaffold should resemble the natural extracellular matrix (ECM) as close as possible both in terms of chemical composition and mechanical properties. Therefore, hydrogel films were developed consisting of methacrylamide-modified gelatin and starch-pentenoate building blocks because the ECM can be considered as a crosslinked hydrogel network consisting of both polysaccharides and structural, signaling and cell-adhesive proteins. For the gelatin hydrogels, three different substitution degrees were evaluated including 31%, 72% and 95%. A substitution degree of 32% was applied for the starch-pentenoate building block. Pure gelatin hydrogels films as well as interpenetrating networks with gelatin and starch were developed. Subsequently, these films were characterized using gel fraction and swelling experiments, high resolution-magic angle spinning (1)H NMR spectroscopy, rheology, infrared mapping and atomic force microscopy. The results indicate that both the mechanical properties and the swelling extent of the developed hydrogel films can be controlled by varying the chemical composition and the degree of substitution of the methacrylamide-modified gelatin applied. The storage moduli of the developed materials ranged between 14 and 63kPa. Phase separation was observed for the IPNs for which separated starch domains could be distinguished located in the surrounding gelatin matrix. Furthermore, we evaluated the affinity of aggrecan for gelatin by atomic force microscopy and radiolabeling experiments. We found that aggrecan can be applied as a bioactive coating for gelatin hydrogels by a straightforward physisorption procedure. Thus, we achieved distinct fine-tuning of the physico-chemical properties of these hydrogels which render them promising candidates for tissue engineering approaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

Zymographic analysis using gelatin-coated film of the effect of etanercept on the extracellular matrix-degrading activity in synovial fluids of rheumatoid arthritis patients.

PubMed

Kamataki, Akihisa; Ishida, Mutsuko; Komagamine, Masataka; Yoshida, Masaaki; Ando, Takanobu; Sawai, Takashi

2016-04-01

Rheumatoid arthritis (RA) is a chronic inflammatory disease. Most RA patients develop cartilage and bone destruction, and various proteinases are involved in the destruction of extracellular matrix of cartilage and bone. The aim of this study is to evaluate the utility of our newly developed method to measure total gelatinolytic activity. We adopted this method for measurement in synovial fluid from RA patients treated by the anti-rheumatic drug etanercept (ETN), a recombinant human soluble tumor necrosis factor receptor fusion protein, and compared the findings with clinical and laboratory data. Enzymatic activity of synovial fluid was analyzed by zymography using gelatin-coated film, and compared with the index of Disease Activity Score of 28 joints - C-reactive protein (DAS28-CRP), CRP and matrix metalloproteinase (MMP)-3 level before and after ETN therapy. Synovial fluids of 19 patients were collected before and after administration of ETN therapy. In nine of 19 patients, who showed a decrease in gelatin-degrading activity in synovial fluid, the index of DAS28-CRP (4.85-2.85, ΔDAS = -2.00) and CRP (3.30-0.94 mg/dL, ΔCRP = -2.36) was alleviated after ETN therapy, while cases with no change or an increase in gelatin-degrading activity showed a modest improvement in clinical data: DAS28-CRP (4.23-3.38, ΔDAS = -0.85) and CRP (1.70-0.74 mg/dL, ΔCRP = -0.96). Our newly developed method for measurement of gelatin-degrading activity in synovial fluid from RA patients is highly practicable and useful for predicting the effect of ETN therapy. © 2013 Asia Pacific League of Associations for Rheumatology and Wiley Publishing Asia Pty Ltd.

Fabrication of cell-benign inverse opal hydrogels for three-dimensional cell culture.

PubMed

Im, Pilseon; Ji, Dong Hwan; Kim, Min Kyung; Kim, Jaeyun

2017-05-15

Inverse opal hydrogels (IOHs) for cell culture were fabricated and optimized using calcium-crosslinked alginate microbeads as sacrificial template and gelatin as a matrix. In contrast to traditional three-dimensional (3D) scaffolds, the gelatin IOHs allowed the utilization of both the macropore surface and inner matrix for cell co-culture. In order to remove templates efficiently for the construction of 3D interconnected macropores and to maintain high cell viability during the template removal process using EDTA solution, various factors in fabrication, including alginate viscosity, alginate concentration, alginate microbeads size, crosslinking calcium concentration, and gelatin network density were investigated. Low viscosity alginate, lower crosslinking calcium ion concentration, and lower concentration of alginate and gelatin were found to obtain high viability of cells encapsulated in the gelatin matrix after removal of the alginate template by EDTA treatment by allowing rapid dissociation and diffusion of alginate polymers. Based on the optimized fabrication conditions, gelatin IOHs showed good potential as a cell co-culture system, applicable to tissue engineering and cancer research. Copyright © 2017 Elsevier Inc. All rights reserved.

Recent advancement of gelatin nanoparticles in drug and vaccine delivery.

PubMed

Sahoo, Nityananda; Sahoo, Ranjan Ku; Biswas, Nikhil; Guha, Arijit; Kuotsu, Ketousetuo

2015-11-01

Novel drug delivery system using nanoscale materials with a broad spectrum of applications provides a new therapeutic foundation for technological integration and innovation. Nanoparticles are suitable drug carrier for various routes of administration as well as rapid recognition by the immune system. Gelatin, the biological macromolecule is a versatile drug/vaccine delivery carrier in pharmaceutical field due to its biodegradable, biocompatible, non-antigenicity and low cost with easy availability. The surface of gelatin nanoparticles can be modified with site-specific ligands, cationized with amine derivatives or, coated with polyethyl glycols to achieve targeted and sustained release drug delivery. Compared to other colloidal carriers, gelatin nanoparticles are better stable in biological fluids to provide the desired controlled and sustained release of entrapped drug molecules. The current review highlights the different formulation aspects of gelatin nanoparticles which affect the particle characteristics like zeta potential, polydispersity index, entrapment efficacy and drug release properties. It has also given emphasis on the major applications of gelatin nanoparticles in drug and vaccine delivery, gene delivery to target tissues and nutraceutical delivery for improving the poor bioavailabity of bioactive phytonutrients. Copyright © 2015 Elsevier B.V. All rights reserved.

Controlled release of sphingosine-1-phosphate agonist with gelatin hydrogels for macrophage recruitment.

PubMed

Murakami, Masahiro; Saito, Takashi; Tabata, Yasuhiko

2014-11-01

The objective of this study is to design a drug delivery system (DDS) for the in vivo promotion of macrophage recruitment. As the drug, a water-insoluble agonist of sphingosine-1-phosphate type 1 receptor (SEW2871) was selected. SEW2871 (SEW) was water-solubilized by micelle formation with gelatin grafted by L-lactic acid oligomer. SEW micelles were mixed with gelatin, followed by dehydrothermal crosslinking of gelatin to obtain gelatin hydrogels incorporating SEW micelles. SEW was released from the hydrogels incorporating SEW micelles in vitro and in vivo. The water-solubilized SEW showed in vitro macrophage migration activity. When implanted into the back subcutis or the skin wound defect of mice, the hydrogel incorporating SEW micelles promoted macrophage migration toward the tissue around the implanted site to a significantly great extent compared with SEW-free hydrogel and that mixed with SEW micelles. The hydrogel is a promising DDS to enhance macrophage recruitment in vivo. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Antitumor activity of cytotoxic T lymphocytes engineered to target vascular endothelial growth factor receptors

NASA Astrophysics Data System (ADS)

Niederman, Thomas M. J.; Ghogawala, Zoher; Carter, Bob S.; Tompkins, Hillary S.; Russell, Margaret M.; Mulligan, Richard C.

2002-05-01

The demonstration that angiogenesis is required for the growth of solid tumors has fueled an intense interest in the development of new therapeutic strategies that target the tumor vasculature. Here we report the development of an immune-based antiangiogenic strategy that is based on the generation of T lymphocytes that possess a killing specificity for cells expressing vascular endothelial growth factor receptors (VEGFRs). To target VEGFR-expressing cells, recombinant retroviral vectors were generated that encoded a chimeric T cell receptor comprised of VEGF sequences linked to intracellular signaling sequences derived from the chain of the T cell receptor. After transduction of primary murine CD8 lymphocytes by such vectors, the transduced cells were shown to possess an efficient killing specificity for cells expressing the VEGF receptor, Flk-1, as measured by in vitro cytotoxicity assays. After adoptive transfer into tumor-bearing mice, the genetically modified cytotoxic T lymphocytes strongly inhibited the growth of a variety of syngeneic murine tumors and human tumor xenografts. An increased effect on in vivo tumor growth inhibition was seen when this therapy was combined with the systemic administration of TNP-470, a conventional angiogenesis inhibitor. The utilization of the immune system to target angiogenic markers expressed on tumor vasculature may prove to be a powerful means for controlling tumor growth.

Renal uptake of radiolabeled octreotide in human subjects is efficiently inhibited by succinylated gelatin.

PubMed

Vegt, Erik; Wetzels, Jack F M; Russel, Frans G M; Masereeuw, Rosalinde; Boerman, Otto C; van Eerd, Juliette E; Corstens, Frans H M; Oyen, Wim J G

2006-03-01

Peptide receptor-mediated radiotherapy of neuroendocrine and other somatostatin receptor-positive tumors with radiolabeled somatostatin analogs has been applied in several experimental settings. The kidneys are the organs responsible for dose-limiting toxicity attributable to the retention of radiolabeled octreotide in the renal cortex, leading to a relatively high radiation dose that may result in irreversible loss of kidney function. The administration of basic amino acids reduces renal uptake but does have significant side effects. We observed that gelatin-based plasma expanders induced tubular low-molecular-weight proteinuria in healthy volunteers, suggesting that components in these solutions can interfere with the tubular reabsorption of proteins and peptides. Here, we studied the effects of infusion of low doses of the plasma expander succinylated gelatin (GELO) on the renal uptake of 111In-labeled octreotide (111In-OCT). Five healthy volunteers were given 111In-OCT, first in combination with normal saline and 2 wk later in combination with GELO. Scintigraphic images of the kidneys as well as blood and urine samples were analyzed. To exclude a nonspecific hemodynamic effect of the plasma expander, the procedure was repeated with 5 other volunteers who received the carbohydrate-based plasma expander hydroxyethyl starch (HES). Low doses of GELO were able to effectively reduce the kidney retention of 111In-OCT. The renal radiation dose was significantly reduced by 45% +/- 10% (mean +/- SD) (P = 0.006), whereas HES showed no significant effect (0% +/- 12%). The infusion of GELO did not cause any side effects. GELO effectively reduces the renal uptake of 111In-OCT. In contrast to currently used mixtures of amino acids, GELO does not cause any side effects.

Quantitative detection of bovine and porcine gelatin difference using surface plasmon resonance based biosensor

NASA Astrophysics Data System (ADS)

Wardani, Devy P.; Arifin, Muhammad; Suharyadi, Edi; Abraha, Kamsul

2015-05-01

Gelatin is a biopolymer derived from collagen that is widely used in food and pharmaceutical products. Due to some religion restrictions and health issues regarding the gelatin consumption which is extracted from certain species, it is necessary to establish a robust, reliable, sensitive and simple quantitative method to detect gelatin from different parent collagen species. To the best of our knowledge, there has not been a gelatin differentiation method based on optical sensor that could detect gelatin from different species quantitatively. Surface plasmon resonance (SPR) based biosensor is known to be a sensitive, simple and label free optical method for detecting biomaterials that is able to do quantitative detection. Therefore, we have utilized SPR-based biosensor to detect the differentiation between bovine and porcine gelatin in various concentration, from 0% to 10% (w/w). Here, we report the ability of SPR-based biosensor to detect difference between both gelatins, its sensitivity toward the gelatin concentration change, its reliability and limit of detection (LOD) and limit of quantification (LOQ) of the sensor. The sensor's LOD and LOQ towards bovine gelatin concentration are 0.38% and 1.26% (w/w), while towards porcine gelatin concentration are 0.66% and 2.20% (w/w), respectively. The results show that SPR-based biosensor is a promising tool for detecting gelatin from different raw materials quantitatively.

The properties of gelatin-poly (gamma-glutamic acid) hydrogels as biological glues.

PubMed

Hsu, Shan-Hui; Lin, Chen-Huan

2007-01-01

The influence of the molecular weight and the type of gelatin (A or B), as well as the molecular weight of poly (gamma-glutamic acid) (gamma-PGA), on the properties of gelatin/gamma-PGA mixed bioadhesives were studied. The gelation of the system was enhanced by a crosslinker, 1-(3-dimethylaminopropyl)-3-(ethylcarbodiimide) hydrochloride (EDC). The gelation time of the bioadhesives was analyzed using rheological measurements. The results indicated that the type of gelatin was a critical factor in determining the gelation time of the biological glues. The mixed glues had greater bonding strength and smaller gelation times as the molecular weight of gamma-PGA or gelatin increased. The swelling ratio decreased and the denaturation temperature increased upon raising the EDC concentration, indicating a greater degree of crosslinking at higher EDC concentrations. The mixed glues crosslinked with various concentrations of EDC (1.7-2.5%) showed no cytotoxicity to fibroblasts. In addition, no significant inflammatory response was observed in the rat subcutaneous implantation. The bioadhesives based on gelatin/gamma-PGA remained at the site for 7 days while the fibrin glue had almost completely degraded. By choosing the appropriate gelatin type and higher molecular weight gamma-PGA in the mixtures, the gelatin/gamma-PGA biological glues could serve as soft tissue adhesives. Rheological characterization was essential in the evaluation of biological glues.

Luteolin Inhibits Human Prostate Tumor Growth by Suppressing Vascular Endothelial Growth Factor Receptor 2-Mediated Angiogenesis

PubMed Central

Pratheeshkumar, Poyil; Son, Young-Ok; Budhraja, Amit; Wang, Xin; Ding, Songze; Wang, Lei; Hitron, Andrew; Lee, Jeong-Chae; Kim, Donghern; Divya, Sasidharan Padmaja; Chen, Gang; Zhang, Zhuo; Luo, Jia; Shi, Xianglin

2012-01-01

Angiogenesis, the formation of new blood vessels from pre-existing vascular beds, is essential for tumor growth, invasion, and metastasis. Luteolin is a common dietary flavonoid found in fruits and vegetables. We studied the antiangiogenic activity of luteolin using in vitro, ex vivo, and in vivo models. In vitro studies using rat aortic ring assay showed that luteolin at non-toxic concentrations significantly inhibited microvessel sprouting and proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Luteolin also inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM) and matrigel plug assay. Gelatin zymographic analysis demonstrated the inhibitory effect of luteolin on the activation of matrix metalloproteinases MMP-2 and MMP-9. Western blot analysis showed that luteolin suppressed VEGF induced phosphorylation of VEGF receptor 2 and their downstream protein kinases AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 in HUVECs. Proinflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α level were significantly reduced by the treatment of luteolin in PC-3 cells. Luteolin (10 mg/kg/d) significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that luteolin inhibited tumorigenesis by targeting angiogenesis. CD31 and CD34 immunohistochemical staining further revealed that the microvessel density could be remarkably suppressed by luteolin. Moreover, luteolin reduced cell viability and induced apoptosis in prostate cancer cells, which were correlated with the downregulation of AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 expressions. Taken together, our findings demonstrate that luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis. PMID:23300633

Simultaneous detection of bovine and porcine DNA in pharmaceutical gelatin capsules by duplex PCR assay for Halal authentication.

PubMed

Nikzad, Jafar; Shahhosseini, Soraya; Tabarzad, Maryam; Nafissi-Varcheh, Nastaran; Torshabi, Maryam

2017-02-14

In the pharmaceutical industry, hard- and soft-shelled capsules are typically made from gelatin, commonly derived from bovine and porcine sources. To ensure that pharmaceutical products comply with halal regulations in Muslim countries (no porcine products allowed), development of a valid, reliable, quick, and most importantly, cost-effective tests are of utmost importance. We developed a species-specific duplex polymerase chain reaction (PCR) assay targeting 149 bp porcine and 271 bp bovine mitochondrial DNA (mtDNA) to simultaneously detect both porcine and bovine DNA (in one reaction at the same time) in gelatin. Some additional simplex PCR tests (targeting 126 bp bovine and 212 bp porcine mtDNA) and real-time PCR using a commercially available kit (for identification of porcine DNA) were used to verify the selectivity and sensitivity of our duplex PCR. After optimization of DNA extraction and PCR methods, hard/soft pharmaceutical gelatin capsules (containing drug) were tested for the presence of porcine and/or bovine DNA. Duplex PCR detected the presence of as little as 0.1% porcine DNA, which was more accurate than the commercially available kit. Of all gelatin capsules tested (n = 24), 50% contained porcine DNA (pure porcine gelatin alone or in combination with bovine gelatin). Duplex PCR presents an easy-to-follow, quick, low-cost and reliable method to simultaneously detect porcine and bovine DNAs (>100 bp) in minute amounts in highly processed gelatin-containing pharmaceutical products (with a 0.1% sensitivity for porcine DNA) which may be used for halal authentication. Simultaneous detection of porcine and bovine DNA in gelatin capsules by duplex PCR.

Distortion of the temporary cavity and its influence on staining in firearm barrels.

PubMed

Schyma, Christian; Müller, Rolf; Brenčičová, Eva; Brünig, Julia

2018-06-01

After contact shots to the head, biological traces can be found inside the barrel of the firearm. Experimental protocols to generate this sort of staining, using 12 cm gelatin cubes containing thin foil bags filled with acrylic paint, human blood, and radiocontrast agent, have been developed. Previous research on shots fired at a distance has shown the underlay sustaining these gelatin cubes has an influence on experimental results. This study was conducted to investigate the role of the sustaining base of the gelatin blocks during contact shots, and its influence on the staining result inside firearm barrels. Eighteen contact shots were performed using 22 LR, 32 ACP (7.65 Browning) and 9 mm Luger semi-automatic pistols. With each pistol, shots were fired onto six gelatin cubes; three placed upon a rigid platform and three upon an elastic underlay. The shots were recorded by a high-speed video camera as they penetrated the gelatin cube. Any staining present inside the firearm barrels after the shots were fired was documented by endoscopy. Cross sections of the gelatin blocks were then compared to the high-speed video. It was found that the nature of the staining inside the barrel was not influenced by the underlay sustaining the target model. In the experiment using a 9 mm Luger, the rigid counterfort provoked a visible distortion of the temporary cavity, but, cross sectional analysis of the gelatin cubes did not reveal a relevant influence of the sustaining underlay on the crack length in the gelatin. This could be explained by a secondary expansion of the temporary cavity left by the projectile as a consequence of subsequent inflow of muzzle gases.

Synthesis and Characterization of Gelatin-Based Crosslinkers for the Fabrication of Superabsorbent Hydrogels

PubMed Central

Amonpattaratkit, Penphitcha; Khunmanee, Sureerat; Kim, Dong Hyun; Park, Hansoo

2017-01-01

In this work, crosslinkers were prepared by conjugating high- and low-molecular-weight gelatin with different mole ratios of itaconic acid (IA) with double bonds. Then, the gelatin-itaconic acid (gelatin-IA) crosslinkers were compared with the gelatin-methacrylate (gelatin-MA) crosslinkers. The molecular weights and structures of gelatin-MA and gelatin-IA were confirmed using gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR). Additionally, the swelling ratio and biodegradation properties of the hydrogels using IA as starting monomers and gelatin-IA and gelatin-MA as crosslinkers were investigated. Both hydrogels prepared with high and low molecular weights of gelatin-IA showed higher swelling ratios than those prepared with the gelatin-MA. The results also showed that absorbent hydrogels with different biodegradabilities and swelling ratios could be prepared by changing the ratio of the gelatin-based crosslinkers. PMID:28773186

Insight to drug delivery aspects for colorectal cancer.

PubMed

Gulbake, Arvind; Jain, Aviral; Jain, Ashish; Jain, Ankit; Jain, Sanjay K

2016-01-14

Colorectal cancer (CRC) is the third most common cancer diagnosed worldwide in human beings. Surgery, chemotherapy, radiotherapy and targeted therapies are the conventional four approaches which are currently used for the treatment of CRC. The site specific delivery of chemotherapeutics to their site of action would increase effectiveness with reducing side effects. Targeted oral drug delivery systems based on polysaccharides are being investigated to target and deliver chemotherapeutic and chemopreventive agents directly to colon and rectum. Site-specific drug delivery to colon increases its concentration at the target site, and thus requires a lower dose and hence abridged side effects. Some novel therapies are also briefly discussed in article such as receptor (epidermal growth factor receptor, folate receptor, wheat germ agglutinin, VEGF receptor, hyaluronic acid receptor) based targeting therapy; colon targeted proapoptotic anticancer drug delivery system, gene therapy. Even though good treatment options are available for CRC, the ultimate therapeutic approach is to avert the incidence of CRC. It was also found that CRCs could be prevented by diet and nutrition such as calcium, vitamin D, curcumin, quercetin and fish oil supplements. Immunotherapy and vaccination are used nowadays which are showing better results against CRC.

Antibodies directed against receptor tyrosine kinases

PubMed Central

FAUVEL, Bénédicte; Yasri, Aziz

2014-01-01

Approximately 30 therapeutic monoclonal antibodies have already been approved for cancers and inflammatory diseases, and monoclonal antibodies continue to be one of the fastest growing classes of therapeutic molecules. Because aberrant signaling by receptor tyrosine kinases (RTKs) is a commonly observed factor in cancer, most of the subclasses of RTKs are being extensively studied as potential targets for treating malignancies. The first two RTKs that have been targeted by antibody therapy, with five currently marketed antibodies, are the growth factor receptors EGFR and HER2. However, due to systemic side effects, refractory patients and the development of drug resistance, these treatments are being challenged by emerging therapeutics. This review examines current monoclonal antibody therapies against RTKs. After an analysis of agents that have already been approved, we present an analysis of antibodies in clinical development that target RTKs. Finally, we highlight promising RTKs that are emerging as new oncological targets for antibody-based therapy. PMID:24859229

Genomic Alterations in Advanced Esophageal Cancer May Lead to Subtype-Specific Therapies

PubMed Central

Forde, Patrick M.

2013-01-01

The development of targeted agents for metastatic esophageal or gastroesophageal junction (GEJ) tumors has been limited when compared with that for other common tumors. To date, the anti-human epidermal growth factor receptor-2 (HER-2) antibody, trastuzumab, in combination with chemotherapy, is the only approved novel agent for these cancers, and its use is limited to the small population of patients whose tumors overexpress HER-2. Despite recent progress in the field, median overall survival remains only 8–12 months for patients with stage IV esophageal or GEJ cancer. In this article, we examine the molecular aberrations thought to drive the development and spread of esophageal cancer and identify promising targets for specific tumor inhibition. Data from clinical studies of targeted agents are reviewed, including epidermal growth factor receptor antibodies, tyrosine kinase inhibitors, HER-2, and vascular endothelial growth factor-directed therapy. Current and future targets include MET, fibroblast growth factor receptor, and immune-based therapies. Evidence from trials to date suggests that molecularly unselected patient cohorts derive minimal benefit from most target-specific agents, suggesting that future collaborative investigation should focus on preselected molecular subgroups of patients with this challenging heterogeneous disease. PMID:23853247

Modulation of Insulin-Like Growth Factor-1 Receptor and its Signaling Network for the Treatment of Cancer: Current Status and Future Perspectives

PubMed Central

Jin, Meizhong; Buck, Elizabeth; Mulvihill, Mark J.

2013-01-01

Based on over three decades of pre-clinical data, insulin-like growth factor-1 receptor (IGF-1R) signaling has gained recognition as a promoter of tumorogenesis, driving cell survival and proliferation in multiple human cancers. As a result, IGF-1R has been pursued as a target for cancer treatment. Early pioneering efforts targeting IGF-1R focused on highly selective monoclonal antibodies, with multiple agents advancing to clinical trials. However, despite some initial promising results, recent clinical disclosures have been less encouraging. Moreover, recent studies have revealed that IGF-1R participates in a dynamic and complex signaling network, interacting with additional targets and pathways thereof through various crosstalk and compensatory signaling mechanisms. Such mechanisms of bypass signaling help to shed some light on the decreased effectiveness of selective IGF-1R targeted therapies (e.g. monoclonal antibodies) and suggest that targeting multiple nodes within this signaling network might be necessary to produce a more effective therapeutic response. Additionally, such findings have led to the development of small molecule IGF-1R inhibitors which also co-inhibit additional targets such as insulin receptor and epidermal growth factor receptor. Such findings have helped to guide the design rationale of numerous drug combinations that are currently being evaluated in clinical trials. PMID:25992224

Isolation of fish skin and bone gelatin from tilapia (Oreochromis niloticus): Response surface approach

NASA Astrophysics Data System (ADS)

Arpi, N.; Fahrizal; Novita, M.

2018-03-01

In this study, gelatin from fish collagen, as one of halal sources, was extracted from tilapia (Oreochromis niloticus) skin and bone, by using Response Surface Methodology to optimize gelatin extraction conditions. Concentrations of alkaline NaOH and acid HCl, in the pretreatment process, and temperatures in extraction process were chosen as independent variables, while dependent variables were yield, gel strength, and emulsion activity index (EAI). The result of investigation showed that lower NaOH pretreatment concentrations provided proper pH extraction conditions which combine with higher extraction temperatures resulted in high gelatin yield. However, gelatin emulsion activity index increased proportionally to the decreased in NaOH concentrations and extraction temperatures. No significant effect of the three independent variables on the gelatin gel strength. RSM optimization process resulted in optimum gelatin extraction process conditions using alkaline NaOH concentration of 0.77 N, acid HCl of 0.59 N, and extraction temperature of 66.80 °C. The optimal solution formula had optimization targets of 94.38%.

Characterizing the interaction among bullet, body armor, and human and surrogate targets.

PubMed

Shen, Weixin; Niu, Yuqing; Bykanova, Lucy; Laurence, Peter; Link, Norman

2010-12-01

This study used a combined experimental and modeling approach to characterize and quantify the interaction among bullet, body armor, and human surrogate targets during the 10-1000 μs range that is crucial to evaluating the protective effectiveness of body armor against blunt injuries. Ballistic tests incorporating high-speed flash X-ray measurements were performed to acquire the deformations of bullets and body armor samples placed against ballistic clay and gelatin targets with images taken between 10 μs and 1 ms of the initial impact. Finite element models (FEMs) of bullet, armor, and gelatin and clay targets were developed with material parameters selected to best fit model calculations to the test measurements. FEMs of bullet and armor interactions were then assembled with a FEM of a human torso and FEMs of clay and gelatin blocks in the shape of a human torso to examine the effects of target material and geometry on the interaction. Test and simulation results revealed three distinct loading phases during the interaction. In the first phase, the bullet was significantly slowed in about 60 μs as it transferred a major portion of its energy into the body armor. In the second phase, fibers inside the armor were pulled toward the point of impact and kept on absorbing energy until about 100 μs after the initial impact when energy absorption reached its peak. In the third phase, the deformation on the armor's back face continued to grow and energies inside both armor and targets redistributed through wave propagation. The results indicated that armor deformation and energy absorption in the second and third phases were significantly affected by the material properties (density and stiffness) and geometrical characteristics (curvature and gap at the armor-target interface) of the targets. Valid surrogate targets for testing the ballistic resistance of the armor need to account for these factors and produce the same armor deformation and energy absorption as on a human torso until at least about 100 μs (maximum armor energy absorption) or more preferably 300 μs (maximum armor deformation).

Effect of TLR ligands co-encapsulated with multiepitopic antigen in nanoliposomes targeted to human DCs via Fc receptor for cancer vaccines.

PubMed

Rueda, Felix; Eich, Christina; Cordobilla, Begoña; Domingo, Pere; Acosta, Gerardo; Albericio, Fernando; Cruz, Luis J; Domingo, Joan C

2017-11-01

Nanoliposomes (NLs) hold promise as new highly specific nanomedicine for anti-tumor vaccines, since they could be targeted to specific receptors on dendritic cell (DC) to induce maturation and activation and increase the anti-tumor immune response. Here we studied a NLs formulation targeted or not to FcR (the receptor for the IgG Fc fragment) for the treatment of androgen-responsive prostate cancer. Luteinizing-hormone-releasing hormone (LHRH) peptide (B- and T-cell epitopes), in tandem with a tetanus toxoid T-helper epitope (830-844 region) and several TLR (Toll-Like Receptor) ligands as adjuvants were co-encapsulated. Specific uptake in vitro of LHRH-TT liposomes targeted to the FcRs of human DCs was enhanced. DC maturation/activation, cytokine production and lymphocyte activation were consistently higher in targeted than non-targeted liposomes. Similar increase was observed as more adjuvants were administrated. Targeting to specific receptor and co-encapsulation of several TLR adjuvants are essential factors for the immune response in peptide based liposome vaccine. Copyright © 2017 Elsevier GmbH. All rights reserved.

The relationship between red meat allergy and sensitization to gelatin and galactose-alpha-1,3-galactose

PubMed Central

Mullins, Raymond James; James, Hayley; Platts-Mills, Thomas A.E.; Commins, Scott

2012-01-01

Background We have observed patients clinically allergic to red meat and meat-derived gelatin. Objective We describe a prospective evaluation of the clinical significance of gelatin sensitization, the predictive value of a positive test and an examination of the relationship between allergic reactions to red meat and sensitization to gelatin and alpha-Gal. Methods Adult patients evaluated 1997-2011 for suspected allergy/anaphylaxis to medication, insect venom or food were skin tested with gelatin colloid. In vitro (ImmunoCap) testing was undertaken where possible. Results Positive gelatin tests were observed in 40/1335 individuals; 30/40 patients with red meat allergy (12 also clinically allergic to gelatin); 2/2 with gelatin colloid anaphylaxis; 4/172 with idiopathic anaphylaxis (all responded to intravenous gelatin challenge of 0.02 to 0.4g); 4/368 with drug allergy. Testing was negative in all patients with venom allergy (n=241), non-meat food allergy (n=222), and miscellaneous disorders (n=290). ImmunoCap was positive to alpha-Gal in 20/24 meat allergics and in 20/22 with positive gelatin skin tests. The results of gelatin skin testing and anti-alpha-Gal IgE were strongly correlated (r=0.46; P<0.01). Alpha-Gal was detected in bovine gelatin colloids at concentrations of ~ 0.44 to 0.52ug/gm gelatin by inhibition radioimmunoassay. Conclusion Most patients allergic to red meat were sensitized to gelatin and a subset was clinically allergic to both. The detection of alpha-Gal in gelatin and correlation between the results of alpha-Gal and gelatin testing raises the possibility that alpha-Gal IgE may be the target of reactivity to gelatin. The pathogenic relationship between tick bites and sensitization to red meat, alpha-Gal and gelatin (with or without clinical reactivity) remains uncertain. PMID:22480538

Effects of chicken by-product gelatin on the physicochemical properties and texture of chocolate spread.

PubMed

Almeida, Poliana Fernandes; Lannes, Suzana Caetano da Silva

2017-10-01

Chocolate spread has a fat-based formulation and the application of gelatin as a fat replacement is related to the demand for healthier foods. The aim of this study was to evaluate the influence of gelatin as a by-product from the poultry industry in the fat replacement of chocolate spread. Vegetable fat was replaced (15, 25, 50, 75, and 100%) with gelatin (0.3, 0.5, 0.8, 1.0, and 1.2%) using a central composite rotatable design and the effects were evaluated by a response surface methodology. Formulations with a greater proportion of fat were lighter, of higher volume and lower density. As expected, water activity was intensified in low-fat formulations. The consistency was controlled mainly by the properties of the gelatin phase. The formulations with 50 and 75% fat replacement and 0.5-1.0% gelatin had satisfactory spreadability at 10C. All formulations were spreadable at 20C. Low-fat samples with low gelatin concentrations, at 30C, had very low consistency. Statistically, the properties were significantly influenced by the factors analyzed according to the mathematical models. Although several studies have been conducted on obtaining alternative gelatin sources for mammals, the extracted gelatin from poultry by-product is still little explored and the knowledge on the application in food products, particularly in complex systems such as emulsions, has not been well established. The development of a low-fat food should take into account the complexity of the system involved, such as the emulsion spreads. The incorporation of gelatin in aqueous solution is a challenging task because the physical properties and the rheological behavior can be strongly influenced. Given the nutritional and functional properties of the gelatin and chocolate and its wide acceptability among the consumers, the incorporation of these two ingredients in the development of a new product sets up a promising study. © 2016 Wiley Periodicals, Inc.

The physico-chemical properties of pangas catfish (Pangasius pangasius) skin gelatin

NASA Astrophysics Data System (ADS)

Pradarameswari, K. A.; Zaelani, K.; Waluyo, E.; Nurdiani, R.

2018-04-01

Gelatin can be used as emulsifier and stabilizer in food products. Until now, the most widely used raw materials for the production of gelatin industry are cow bone, cow skin and pig skin. Fish gelatin has been highlighted as a better alternative to replace mammals gelatin based on ethical and religious perspective. Fish gelatin was extracted from Pangas catfish skin to determine its physico-chemical properties. Different temperatures (45 °C, 50 °C, 55 °C) were employed during gelatin extraction. Higher temperature increased the yield and fat contents of Pangas catfish skin gelatin. In contrary, higher water, protein, ash contents were observed during lower temperature. Temperature significantly (p < 0.05) affected the gel strength, viscosity, melting point, and gelling point of fish skin gelatin. Based on the FTIR spectrum catfish skin gelatin functional groups can be identified as N-H, O-H, C = H, C-O and C-H.

Winner of the society for biomaterials student award in the Ph.D. category for the annual meeting of the society for biomaterials, april 11-14, 2018, Atlanta, GA: Development of a bimodal, in situ crosslinking method to achieve multifactor release from electrospun gelatin.

PubMed

Kishan, Alysha; Walker, Taneidra; Sears, Nick; Wilems, Thomas; Cosgriff-Hernandez, Elizabeth

2018-05-01

To better mimic native tissue microenvironments, current efforts have moved beyond single growth factor delivery to more complex multiple growth factor delivery with distinct release profiles. Electrospun gelatin, a widely investigated drug delivery vehicle, requires postprocessing crosslinking techniques that generate a mesh with uniform crosslinking density, limiting the ability to deliver multiple factors at different rates. Herein, we describe a method to independently control release of multiple factors from a single electrospun gelatin mesh. Two in situ crosslinking modalities, photocrosslinking of methacyrlated gelatin and reactive crosslinking of gelatin with a diisocyanate, are coelectrospun to generate distinct fiber populations with different crosslinking chemistry and density in a single mesh. The photocrosslinked gelatin-methacrylate resulted in a relatively rapid release of a model protein (48 ± 12% at day 1, 96 ± 3% at day 10) due to diffusion of embedded protein from the crosslinked fibers. The reactive crosslinking system displayed a more sustained release (7 ± 5% at day 1, 33 ± 2% at day 10) that was attributed to the conjugation of protein to gelatin with the diisocyanate, requiring degradation of gelatin prior to diffusion out of the fibers. Both modalities displayed tunable release profiles. Subsequent release studies of a cospun mesh with two different crosslinked fiber populations confirmed that the cospun mesh displayed multifactor release with independent release profiles. Overall, this bimodal, in situ crosslinking approach enables the delivery of multiple factors with distinct release kinetics from a single mesh and is expected to have broad utility in tissue engineering. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1155-1164, 2018. © 2018 Wiley Periodicals, Inc.

Current advances in biomarkers for targeted therapy in triple-negative breast cancer

PubMed Central

Fleisher, Brett; Clarke, Charlotte; Ait-Oudhia, Sihem

2016-01-01

Triple-negative breast cancer (TNBC) is a complex heterogeneous disease characterized by the absence of three hallmark receptors: human epidermal growth factor receptor 2, estrogen receptor, and progesterone receptor. Compared to other breast cancer subtypes, TNBC is more aggressive, has a higher prevalence in African-Americans, and more frequently affects younger patients. Currently, TNBC lacks clinically accepted targets for tailored therapy, warranting the need for candidate biomarkers. BiomarkerBase, an online platform used to find biomarkers reported in clinical trials, was utilized to screen all potential biomarkers for TNBC and select only the ones registered in completed TNBC trials through clinicaltrials.gov. The selected candidate biomarkers were classified as surrogate, prognostic, predictive, or pharmacodynamic (PD) and organized by location in the blood, on the cell surface, in the cytoplasm, or in the nucleus. Blood biomarkers include vascular endothelial growth factor/vascular endothelial growth factor receptor and interleukin-8 (IL-8); cell surface biomarkers include EGFR, insulin-like growth factor binding protein, c-Kit, c-Met, and PD-L1; cytoplasm biomarkers include PIK3CA, pAKT/S6/p4E-BP1, PTEN, ALDH1, and the PIK3CA/AKT/mTOR-related metabolites; and nucleus biomarkers include BRCA1, the gluco-corticoid receptor, TP53, and Ki67. Candidate biomarkers were further organized into a “cellular protein network” that demonstrates potential connectivity. This review provides an inventory and reference point for promising biomarkers for breakthrough targeted therapies in TNBC. PMID:27785100

The correlation between gelatin macroscale differences and nanoparticle properties: providing insight into biopolymer variability.

PubMed

Stevenson, André T; Jankus, Danny J; Tarshis, Max A; Whittington, Abby R

2018-05-21

From therapeutic delivery to sustainable packaging, manipulation of biopolymers into nanostructures imparts biocompatibility to numerous materials with minimal environmental pollution during processing. While biopolymers are appealing natural based materials, the lack of nanoparticle (NP) physicochemical consistency has decreased their nanoscale translation into actual products. Insights regarding the macroscale and nanoscale property variation of gelatin, one of the most common biopolymers already utilized in its bulk form, are presented. Novel correlations between macroscale and nanoscale properties were made by characterizing similar gelatin rigidities obtained from different manufacturers. Samples with significant differences in clarity, indicating sample purity, obtained the largest deviations in NP diameter. Furthermore, a statistically significant positive correlation between macroscale molecular weight dispersity and NP diameter was determined. New theoretical calculations proposing the limited number of gelatin chains that can aggregate and subsequently get crosslinked for NP formation were presented as one possible reason to substantiate the correlation analysis. NP charge and crosslinking extent were also related to diameter. Lower gelatin sample molecular weight dispersities produced statistically smaller average diameters (<75 nm), and higher average electrostatic charges (∼30 mV) and crosslinking extents (∼95%), which were independent of gelatin rigidity, conclusions not shown in the literature. This study demonstrates that the molecular weight composition of the starting material is one significant factor affecting gelatin nanoscale properties and must be characterized prior to NP preparation. Identifying gelatin macroscale and nanoscale correlations offers a route toward greater physicochemical property control and reproducibility of new NP formulations for translation to industry.

Gelatin prepared from tuna skin: a risk factor for fish allergy or sensitization?

PubMed

André, Françoise; Cavagna, Sylvie; André, Claude

2003-01-01

Although fish gelatin may represent a useful alternative to bovine or porcine gelatin, the clearly recognized high prevalence of fish allergy could increase the risk of anaphylaxis to gelatin. The rationale for investigating tuna gelatin rather than gelatin from more allergenic fishes is the availability of an industrial gelatin under development. The infrequent occurrence of tuna allergy should influence the safety of a derived product. The present study investigated IgE antibodies to tuna-skin-derived gelatin in adults and children with documented fish allergy or sensitization. Serum samples were taken from 100 consecutive patients with fish allergy or sensitization and tested for IgE antibodies against hydrolyzed or nonhydrolyzed gelatin extracted from tuna skin as compared to extracts from tuna flesh, tuna skin as well as bovine or porcine gelatin. Patients with tuna allergies or sensitization were sensitive to the same tuna species (yellowfin) as that from which the gelatin was obtained. IgE antibodies to these various extracts were analyzed using SDS-PAGE and immunoblotting. Only 3 of the 100 serum samples tested gave evidence of reactivity to gelatin extracted from tuna skin. Cross-reactivity between bovine/porcine and fish gelatin was not observed. The risk of adverse reactions to tuna skin gelatin seems to be significantly lower than the risk of fish allergy. Fish gelatin may represent a valuable alternative to bovine or porcine gelatin. Copyright 2003 S. Karger AG, Basel

Complete tissue coverage achieved by scaffold-based tissue engineering in the fetal sheep model of Myelomeningocele.

PubMed

Watanabe, Miho; Li, Haiying; Kim, Aimee G; Weilerstein, Aaron; Radu, Anteneta; Davey, Marcus; Loukogeorgakis, Stavros; Sánchez, Melissa D; Sumita, Kazutaka; Morimoto, Naoki; Yamamoto, Masaya; Tabata, Yasuhiko; Flake, Alan W

2016-01-01

Myelomeningocele (MMC) is the most severe form of spina bifida, one of the most common congenital anomalies. Although open fetal surgical repair of the MMC defect has been shown to result in improved outcomes, a less invasive approach applicable earlier in gestation than the current open surgical approach between 19 and 26 weeks of gestation is desirable for further improvement of neurological symptoms, as well as reduction of maternal and fetal risks. We previously reported the therapeutic potential of a scaffold-based tissue engineering approach in a fetal rat MMC model. The objective of this study was to confirm the long-term efficacy of this approach in the surgically created fetal sheep MMC model. Gelatin-based or gelatin/collagen hybrid sponges were prepared with and without basic fibroblast growth factor (bFGF) incorporation. The defect was covered by a sponge and secured by a supporting sheet with adhesive at 100 days of gestation or the gelatin/collagen hybrid with bFGF was secured with adhesive without the sheet. Although sheets were found detached at term (140 days' gestation), both gelatin-based and gelatin/collagen hybrid sponges had integrated within the newly formed granulation tissue, resulting in complete coverage of the MMC defect. The release of bFGF from sponges resulted in enhanced formation of granulation tissue and epithelialization. There was also evidence of improved preservation of the spinal cord with less associated damage on histological analysis and reversal of hindbrain herniation. These experiments provide important proof-of-principle evidence of the efficacy of scaffold-based tissue engineered coverage for the prenatal treatment of MMC. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relationship between red meat allergy and sensitization to gelatin and galactose-α-1,3-galactose.

PubMed

Mullins, Raymond James; James, Hayley; Platts-Mills, Thomas A E; Commins, Scott

2012-05-01

We have observed patients clinically allergic to red meat and meat-derived gelatin. We describe a prospective evaluation of the clinical significance of gelatin sensitization, the predictive value of a positive test result, and an examination of the relationship between allergic reactions to red meat and sensitization to gelatin and galactose-α-1,3-galactose (α-Gal). Adult patients evaluated in the 1997-2011 period for suspected allergy/anaphylaxis to medication, insect venom, or food were skin tested with gelatin colloid. In vitro (ImmunoCAP) testing was undertaken where possible. Positive gelatin test results were observed in 40 of 1335 subjects: 30 of 40 patients with red meat allergy (12 also clinically allergic to gelatin), 2 of 2 patients with gelatin colloid-induced anaphylaxis, 4 of 172 patients with idiopathic anaphylaxis (all responded to intravenous gelatin challenge of 0.02-0.4 g), and 4 of 368 patients with drug allergy. Test results were negative in all patients with venom allergy (n = 241), nonmeat food allergy (n = 222), and miscellaneous disorders (n = 290). ImmunoCAP results were positive to α-Gal in 20 of 24 patients with meat allergy and in 20 of 22 patients with positive gelatin skin test results. The results of gelatin skin testing and anti-α-Gal IgE measurements were strongly correlated (r = 0.46, P < .01). α-Gal was detected in bovine gelatin colloids at concentrations of approximately 0.44 to 0.52 μg/g gelatin by means of inhibition RIA. Most patients allergic to red meat were sensitized to gelatin, and a subset was clinically allergic to both. The detection of α-Gal in gelatin and correlation between the results of α-Gal and gelatin testing raise the possibility that α-Gal IgE might be the target of reactivity to gelatin. The pathogenic relationship between tick bites and sensitization to red meat, α-Gal, and gelatin (with or without clinical reactivity) remains uncertain. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

3D-printed porous titanium changed femoral head repair growth patterns: osteogenesis and vascularisation in porous titanium.

PubMed

Zhu, Wei; Zhao, Yan; Ma, Qi; Wang, Yingjie; Wu, Zhihong; Weng, Xisheng

2017-04-01

Osteonecrosis of the femoral head (ONFH) is a major cause of morbidity, and total hip arthroplasty is both traumatic and expensive. Here, we created a gelatine scaffold embedded in uniquely shaped, 3D-printed porous titanium parts, which could attract and promote the proliferation of osteoblasts as well as bone regeneration, as the extracellular matrix (ECM) does in vivo. Interestingly, after hybridisation with platelets, the scaffold exhibited a low yet considerable rate of stable, safe and long-term growth factor release. Additionally, a novel ONFH model was constructed and verified. Scaffolds implanted in this model were found to accelerate bone repair. In conclusion, our scaffold successfully simulates the ECM and considerably accelerates bone regeneration, in which platelets play an indispensable role. We believe that platelets should be emphasised as carriers that may be employed to transport drugs, cytokines and other small molecules to target locations in vivo. In addition, this novel scaffold is a useful material for treating ONFH. An overview of the novel scaffold mimicking the extracellular environment in bone repair. a and b: A gelatine scaffold was cross-linked and freeze-dried within 3D-printed porous titanium. c: Platelets were coated onto the gelatine microscaffold after freeze-drying platelet-rich plasma. d: The microscaffold supported the migration of cells into the titanium pores and their subsequent growth, while the platelets slowly released cell factors, exerting bioactivity.

Cutaneous biocompatible rutin-loaded gelatin-based nanoparticles increase the SPF of the association of UVA and UVB filters.

PubMed

Oliveira, Camila Areias de; Peres, Daniela D'Almeida; Graziola, Fabiana; Chacra, Nádia Araci Bou; Araújo, Gabriel Lima Barros de; Flórido, Ana Catarina; Mota, Joana; Rosado, Catarina; Velasco, Maria Valéria Robles; Rodrigues, Luís Monteiro; Fernandes, Ana Sofia; Baby, André Rolim

2016-01-01

The encapsulation of natural ingredients, such as rutin, can offer improvements in sun protection effectiveness. This strategy can provide enhanced flavonoid content and produces an improved bioactive compound with new physical and functional characteristics. As an alternative to common synthetic-based sunscreens, rutin-entrapped gelatin nanoparticles (GNPs) were designed and associated with ethylhexyl dimethyl PABA (EHDP), ethylhexyl methoxycinnamate (EHMC) and methoxydibenzoylmethane (BMDBM) in sunscreen formulations. The purpose of this study was to develop rutin-loaded gelatin nanoparticles and characterize their physicochemical, thermal, functional and safety properties. Rutin-loaded gelatin nanoparticles increased antioxidant activity by 74% relative to free-rutin (FR) solution. Also, this new ingredient upgraded the Sun Protection Factor (SPF) by 48%, indicating its potential as a raw material for bioactive sunscreens. The safety profile indicated that GNPs and glutaraldehyde (GTA) decreased HaCaT cell viability in a concentration/time-dependent manner. However, both blank nanoparticles (B-NC) and rutin-loaded nanoparticles (R-NC) had good performance on skin compatibility tests. These results functionally characterized rutin-loaded nanoparticles as a safe SPF enhancer in sunscreens, especially in association with UV filters. Copyright © 2015 Elsevier B.V. All rights reserved.

Bovine and Porcine Gelatin Sensitivity in Milk and Meat-Sensitized Children

PubMed Central

Bogdanovic, Jelena; Halsey, Neal A.; Wood, Robert A.; Hamilton, Robert G.

2009-01-01

Capsule Summary Cross-reactive bovine and porcine gelatin-specific IgE antibody is more common in cow’s milk and beef or pork meat-sensitized individuals than previously known and a potential risk factor for allergic reactions to gelatin-containing products (foods, vaccines). PMID:19665767

Ligand-based receptor tyrosine kinase partial agonists: New paradigm for cancer drug discovery?

PubMed

Riese, David J

2011-02-01

INTRODUCTION: Receptor tyrosine kinases (RTKs) are validated targets for oncology drug discovery and several RTK antagonists have been approved for the treatment of human malignancies. Nonetheless, the discovery and development of RTK antagonists has lagged behind the discovery and development of agents that target G-protein coupled receptors. In part, this is because it has been difficult to discover analogs of naturally-occurring RTK agonists that function as antagonists. AREAS COVERED: Here we describe ligands of ErbB receptors that function as partial agonists for these receptors, thereby enabling these ligands to antagonize the activity of full agonists for these receptors. We provide insights into the mechanisms by which these ligands function as antagonists. We discuss how information concerning these mechanisms can be translated into screens for novel small molecule- and antibody-based antagonists of ErbB receptors and how such antagonists hold great potential as targeted cancer chemotherapeutics. EXPERT OPINION: While there have been a number of important key findings into this field, the identification of the structural basis of ligand functional specificity is still of the greatest importance. While it is true that, with some notable exceptions, peptide hormones and growth factors have not proven to be good platforms for oncology drug discovery; addressing the fundamental issues of antagonistic partial agonists for receptor tyrosine kinases has the potential to steer oncology drug discovery in new directions. Mechanism based approaches are now emerging to enable the discovery of RTK partial agonists that may antagonize both agonist-dependent and -independent RTK signaling and may hold tremendous promise as targeted cancer chemotherapeutics.

Gelatin promotes murine fibrosarcoma L929 cell detachment and protects the cells from TNFα-induced cytotoxicity.

PubMed

Wang, Hong-Ju; Li, Meng-Qi; Liu, Wei; Yao, Guo-Dong; Xia, Ming-Yu; Hayashi, Toshihiko; Fujisaki, Hitomi; Hattori, Shunji; Tashiro, Shin-Ichi; Onodera, Satoshi; Ikejima, Takashi

2016-07-01

Gelatin has been considered to exist as intermediate substance of collagen catabolism in tissue remodeling or under inflammatory conditions. We have initiated the study on possible biological functions of gelatin that can exist temporally and locally under the conditions of remodeling and inflammation Materials and methods: To this purpose, we investigated cell proliferation and survival on gelatin-coated dishes and the response to tumor necrosis factor α (TNFα)-induced cytotoxicity in L929 cells. Autophagy level, ATP level, and ROS generation are examined. L929 cells detached from the gelatin-coated dishes and formed multicellular aggregates. TNFα-induced cytotoxicity in L929 cells was inhibited by gelatin-coating culture. The cells on gelatin-coated dishes showed reduced cellular ATP levels and increased adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation, leading to increased ROS generation and autophagy. This study showed that gelatin-coated culture protected L929 cells from TNFα-induced cytotoxicity and suggested for a possible pathophysiological function of gelatin in regulating cellular functions.

Molecular beacon-based real-time PCR method for detection of porcine DNA in gelatin and gelatin capsules.

PubMed

Mohamad, Nurhidayatul Asma; Mustafa, Shuhaimi; Khairil Mokhtar, Nur Fadhilah; El Sheikha, Aly Farag

2018-03-05

The pharmaceutical industry has boosted gelatin consumption worldwide. This is supported by the availability of cost-effective gelatin production from porcine by-products. However, cross-contamination of gelatin materials, where porcine gelatin was unintentionally included in the other animal sources of gelatin, has caused significant concerns about halal authenticity. The real-time polymerase chain reaction (PCR) has enabled a highly specific and sensitive animal species detection method in various food products. Hence, such a technique was employed in the present study to detect and quantify porcine DNA in gelatin using a molecular beacon probe, with differences in performance between mitochondrial (cytochrome b gene) and chromosomal DNA-(MPRE42 repetitive element) based porcine-specific PCR assays being compared. A higher sensitivity was observed in chromosomal DNA (MPRE-PCR assay), where this assay allows the detection of gelatin DNA at amounts as as low as 1 pg, whereas mitochondrial DNA (CBH-PCR assay) can only detect at levels down to 10 pg of gelatin DNA. When an analysis with commercial gelatin and gelatin capsule samples was conducted, the same result was observed, with a significantly more sensitive detection being provided by the repetitive element of chromosomal DNA. The present study has established highly sensitive DNA-based porcine detection systems derived from chromosomal DNA that are feasible for highly processed products such as gelatin and gelatin capsules containing a minute amount of DNA. This sensitive detection method can also be implemented to assist the halal authentication process of various food products available on the market. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Gelatin-based microcarriers as embryonic stem cell delivery system in bone tissue engineering: an in-vitro study.

PubMed

Tielens, S; Declercq, H; Gorski, T; Lippens, E; Schacht, E; Cornelissen, M

2007-03-01

Mouse embryonic stem cells were cultured on commercially available biodegradable macroporous microcarriers. A culture period of 1-2 weeks was needed to colonize the microcarriers. Embryonic stem cells retained their pluripotency for up to 14 days when cultured in medium supplemented with leukemia inhibitory factor. Replacing this medium by differentiation medium for 2 weeks initiated osteogenic differentiation. Encapsulation of the cell-loaded microcarriers in photopolymerizable polymers (methacrylate-endcapped poly-D,L-lactide-co-caprolactone), triacetin/hydroxyethylmethacrylate (HEMA) as solvent and with/without gelatin as porogen, resulted in a homogeneous distribution of the microcarriers in the polymer. As observed by transmission electron microscopy, viability of the cells was optimal when gelatin was omitted and when using triacetin instead of HEMA.

Gelatin-Based Materials in Ocular Tissue Engineering.

PubMed

Rose, James B; Pacelli, Settimio; Haj, Alicia J El; Dua, Harminder S; Hopkinson, Andrew; White, Lisa J; Rose, Felicity R A J

2014-04-17

Gelatin has been used for many years in pharmaceutical formulation, cell culture and tissue engineering on account of its excellent biocompatibility, ease of processing and availability at low cost. Over the last decade gelatin has been extensively evaluated for numerous ocular applications serving as cell-sheet carriers, bio-adhesives and bio-artificial grafts. These different applications naturally have diverse physical, chemical and biological requirements and this has prompted research into the modification of gelatin and its derivatives. The crosslinking of gelatin alone or in combination with natural or synthetic biopolymers has produced a variety of scaffolds that could be suitable for ocular applications. This review focuses on methods to crosslink gelatin-based materials and how the resulting materials have been applied in ocular tissue engineering. Critical discussion of recent innovations in tissue engineering and regenerative medicine will highlight future opportunities for gelatin-based materials in ophthalmology.

Gelatin-Based Materials in Ocular Tissue Engineering

PubMed Central

Rose, James B.; Pacelli, Settimio; El Haj, Alicia J.; Dua, Harminder S.; Hopkinson, Andrew; White, Lisa J.; Rose, Felicity R. A. J.

2014-01-01

Gelatin has been used for many years in pharmaceutical formulation, cell culture and tissue engineering on account of its excellent biocompatibility, ease of processing and availability at low cost. Over the last decade gelatin has been extensively evaluated for numerous ocular applications serving as cell-sheet carriers, bio-adhesives and bio-artificial grafts. These different applications naturally have diverse physical, chemical and biological requirements and this has prompted research into the modification of gelatin and its derivatives. The crosslinking of gelatin alone or in combination with natural or synthetic biopolymers has produced a variety of scaffolds that could be suitable for ocular applications. This review focuses on methods to crosslink gelatin-based materials and how the resulting materials have been applied in ocular tissue engineering. Critical discussion of recent innovations in tissue engineering and regenerative medicine will highlight future opportunities for gelatin-based materials in ophthalmology. PMID:28788609

Physical, mechanical, and barrier properties of sodium alginate/gelatin emulsion based-films incorporated with canola oil

NASA Astrophysics Data System (ADS)

Syarifuddin, A.; Hasmiyani; Dirpan, A.; Mahendradatta, M.

2017-12-01

The development of mixed emulsion-based films formed by sodium alginate/gelatin incorporated with canola oil can offer particular properties such as water vapor barrier properties. The different ratios of sodium alginate/gelatin and sodium alginate/gelatin emulsion-based films incorporated with canola oil were developed and their effects on films’ physical, mechanical and barrier properties were assessed. Here we set out to examine whether canola oil addition and different ratio of sodium alginate/gelatin modified physical, mechanical, and barrier properties of films. To do so, the films were prepared by vary the ratio of sodium alginate/gelatin (2.5, 1, 0.5). Canola oil addition induced changes in moisture content, thickness, solubility, water vapor transmission rate (WVTR), percent elongation at break (p<0.05). In addition, it is apparent that varying ratio of sodium alginate to gelatin induced change the mechanical properties of films. The reduction of sodium alginate to gelatin decreased the tensile strength of both films. Improved values of WVTR, tensile strength and solubility at break were observed when the ratio of sodium alginate/gelatin emulsion film incorporated with canola oil was 2.5. Therefore, different ratio of sodium alginate/gelatin incorporated with canola oil can be used to tailor emulsion films with enhanced water vapor barrier and mechanical properties.

Resistance of dichromated gelatin as photoresist

NASA Astrophysics Data System (ADS)

Lin, Pang; Yan, Yingbai; Jin, Guofan; Wu, Minxian

1999-09-01

Based on the photographic chemistry, chemically hardening method was selected to enhance the anti-etch capability of gelatin. With the consideration of hardener and permeating processing, formaldehyde is the most ideal option due to the smallest molecule size and covalent cross-link with gelatin. After hardened in formaldehyde, the resistance of the gelatin was obtained by etched in 1% HF solution. The result showed that anti-etch capability of the gelatin layer increased with tanning time, but the increasing rate reduced gradually and tended to saturation. Based on the experimental results, dissolving-flaking hypothesis for chemically hardening gelatin was presented. Sol-gel coatings were etched with 1% HF solution. Compared with the etching rate of gelatin layer, it showed that gelatin could be used as resist to fabricate optical elements in sol-gel coating. With the cleaving-etch method and hardening of dichromated gelatin (DCG), DCG was used as a photoresist for fabricating sol-gel optical elements. As an application, a sol-gel random phase plate was fabricated.

FGFR a promising druggable target in cancer: Molecular biology and new drugs.

PubMed

Porta, Rut; Borea, Roberto; Coelho, Andreia; Khan, Shahanavaj; Araújo, António; Reclusa, Pablo; Franchina, Tindara; Van Der Steen, Nele; Van Dam, Peter; Ferri, Jose; Sirera, Rafael; Naing, Aung; Hong, David; Rolfo, Christian

2017-05-01

The Fibroblast Growth Factor Receptor (FGFR) family consists of Tyrosine Kinase Receptors (TKR) involved in several biological functions. Recently, alterations of FGFR have been reported to be important for progression and development of several cancers. In this setting, different studies are trying to evaluate the efficacy of different therapies targeting FGFR. This review summarizes the current status of treatments targeting FGFR, focusing on the trials that are evaluating the FGFR profile as inclusion criteria: Multi-Target, Pan-FGFR Inhibitors and anti-FGF (Fibroblast Growth Factor)/FGFR Monoclonal Antibodies. Most of the TKR share intracellular signaling pathways; therefore, cancer cells tend to overcome the inhibition of one tyrosine kinase receptor by activating another. The future of TKI (Tyrosine Kinase Inhibitor) therapy will potentially come from multi-targeted TKIs that target different TKR simultaneously. It is crucial to understand the interaction of the FGF-FGFR axis with other known driver TKRs. Based on this, it is possible to develop therapeutic strategies targeting multiple connected TKRs at once. One correct step in this direction is the reassessment of multi target inhibitors considering the FGFR status of the tumor. Another opportunity arises from assessing the use of FGFR TKI on patients harboring FGFR alterations. Copyright © 2017 Elsevier B.V. All rights reserved.

Treatment of renal cell carcinoma: Current status and future directions.

PubMed

Barata, Pedro C; Rini, Brian I

2017-11-01

Answer questions and earn CME/CNE Over the past 12 years, medical treatment for renal cell carcinoma (RCC) has transitioned from a nonspecific immune approach (in the cytokine era), to targeted therapy against vascular endothelial growth factor (VEGF), and now to novel immunotherapy agents. Multiple agents-including molecules against vascular endothelial growth factor, platelet-derived growth factor, and related receptors; inhibitors of other targets, such as the mammalian target of rapamycin and the MET and AXL tyrosine-protein kinase receptors; and an immune-checkpoint inhibitor-have been approved based on significant activity in patients with advanced RCC. Despite these advances, important questions remain regarding biomarkers of efficacy, patient selection, and the optimal combination and sequencing of agents. The purpose of this review is to summarize present management and future directions in the treatment of metastatic RCC. CA Cancer J Clin 2017;67:507-524. © 2017 American Cancer Society. © 2017 American Cancer Society.

Design and evaluation of clickable gelatin-oleic nanoparticles using fattigation-platform for cancer therapy.

PubMed

Meghani, Nilesh M; Amin, Hardik H; Park, Chulhun; Park, Jun-Bom; Cui, Jing-Hao; Cao, Qing-Ri; Lee, Beom-Jin

2018-07-10

The principles of bioorthogonal click chemistry and metabolic glycoengineering were applied to produce targeted anti-cancer drug delivery via fattigation-platform-based gelatin-oleic nanoparticles. A sialic acid precursor (Ac 4 ManNAz) was introduced to the cell surface. Gelatin and oleic acid were conjugated by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) chemistry with the subsequent covalent attachment of dibenzocyclooctyne (DBCO) in a click reaction on the cell surface. The physicochemical properties, drug release, in vitro cytotoxicity, and cellular uptake of DBCO-conjugated gelatin oleic nanoparticles (GON-DBCO; particle size, ∼240 nm; zeta potential, 6 mV) were evaluated. Doxorubicin (DOX) was used as a model drug and compared with the reference product, Caelyx®. A549 and MCF-7 cell lines were used for the in vitro studies. GON-DBCO showed high DOX loading and encapsulation efficiencies. In A549 cells, the IC50 value for GON-DBCO-DOX (1.29 µg/ml) was six times lower than that of Caelyx® (10.54 µg/ml); in MCF-7 cells, the IC50 values were 1.78 µg/ml and 2.84 µg/ml, respectively. Confocal microscopy confirmed the click reaction between GON-DBCO and Ac4ManNAz on the cell surface. Flow cytometry data revealed that the intracellular uptake of GON-DBCO-DOX was approximately two times greater than that of GON-DOX and Caelyx®. Thus, the newly designed GON-DBCO-DOX provided a safe and efficient drug delivery system to actively target the anticancer agents. Copyright © 2018 Elsevier B.V. All rights reserved.

Combined effect of protein and oxygen on reactive oxygen and nitrogen species in the plasma treatment of tissue

NASA Astrophysics Data System (ADS)

Gaur, Nishtha; Szili, Endre J.; Oh, Jun-Seok; Hong, Sung-Ha; Michelmore, Andrew; Graves, David B.; Hatta, Akimitsu; Short, Robert D.

2015-09-01

The influence of protein and molecular, ground state oxygen (O2) on the plasma generation, and transport of reactive oxygen and nitrogen species (RONS) in tissue are investigated. A tissue target, comprising a 1 mm thick gelatin film (a surrogate for real tissue), is placed on top of a 96-well plate; each well is filled with phosphate buffered saline (PBS, pH 7.4) containing one fluorescent or colorimetric reporter that is specific for one of three RONS (i.e., H2O2, NO2-, or OH•) or a broad spectrum reactive oxygen species reporter (2,7-dichlorodihydrofluorescein). A helium cold atmospheric plasma (CAP) jet contacts the top of the gelatin surface, and the concentrations of RONS generated in PBS are measured on a microplate reader. The data show that H2O2, NO2-, or OH• are generated in PBS underneath the target. Independently, measurements are made of the O2 concentration in the PBS with and without the gelatin target. Adding bovine serum albumin protein to the PBS or gelatin shows that protein either raises or inhibits RONS depending upon the O2 concentration. Our results are discussed in the context of plasma-soft tissue interactions that are important in the development of CAP technology for medicine, biology, and food manufacturing.

Micromixer Based Preparation of Functionalized Liposomes and Targeting Drug Delivery.

PubMed

Jia, Xiangqian; Wang, Weizhi; Han, Qiuju; Wang, Zihua; Jia, Yunhong; Hu, Zhiyuan

2016-04-14

We present here a specific targeting nanocarrier system by functionalization of liposomes with one new type of breast cancer targeting peptide (H6, YLFFVFER) by a micromixer with high efficiency. Antitumor drugs could be successfully delivered into human epidermal growth factor receptor 2 (HER2) positive breast cancer cells with high efficiency in both in vivo and ex vivo models.

Motion-Based pH Sensing Based on the Cartridge-Case-like Micromotor.

PubMed

Su, Yajun; Ge, Ya; Liu, Limei; Zhang, Lina; Liu, Mei; Sun, Yunyu; Zhang, Hui; Dong, Bin

2016-02-17

In this paper, we report a novel cartridge-case-like micromotor. The micromotor, which is fabricated by the template synthesis method, consists of a gelatin shell with platinum nanoparticles decorating its inner surface. Intriguingly, the resulting cartridge-case-like structure exhibits a pH-dependent "open and close" feature, which originates from the pH responsiveness of the gelatin material. On the basis of the catalytic activity of the platinum nanoparticle inside the gelatin shell, the resulting cartridge-case-like structure is capable of moving autonomously in the aqueous solution containing the hydrogen peroxide fuel. More interestingly, we find out that the micromotor can be utilized as a motion-based pH sensor over the whole pH range. The moving velocity of the micromotor increases monotonically with the increase of pH of the analyte solution. Three different factors are considered to be responsible for the proportional relation between the motion speed and pH of the analyte solution: the peroxidase-like and oxidase-like catalytic behavior of the platinum nanoparticle at low and high pH, the volumetric decomposition of the hydrogen peroxide under the basic condition and the pH-dependent catalytic activity of the platinum nanoparticle caused by the swelling/deswelling behavior of the gelatin material. The current work highlights the impact of the material properties on the motion behavior of a micromotor, thus paving the way toward its application in the motion-based sensing field.

Gelatin as Biomaterial for Tissue Engineering.

PubMed

Echave, Mari C; Saenz del Burgo, Laura; Pedraz, Jose L; Orive, Gorka

2017-01-01

Tissue engineering is considered one of the most important therapeutic strategies of regenerative medicine. The main objective of these new technologies is the development of substitutes made with biomaterials that are able to heal, repair or regenerate injured or diseased tissues and organs. These constructs seek to unlock the limited ability of human tissues and organs to regenerate. In this review, we highlight the convenient intrinsic properties of gelatin for the design and development of advanced systems for tissue engineering. Gelatin is a natural origin protein derived from collagen hydrolysis. We outline herein a state of the art of gelatin-based composites in order to overcome limitations of this polymeric material and modulate the properties of the formulations. Control release of bioactive molecules, formulations with conductive properties or systems with improved mechanical properties can be obtained using gelatin composites. Many studies have found that the use of calcium phosphate ceramics and diverse synthetic polymers in combination with gelatin improve the mechanical properties of the structures. On the other hand, polyaniline and carbon-based nanosubstrates are interesting molecules to provide gelatin-based systems with conductive properties, especially for cardiac and nerve tissue engineering. Finally, this review provides an overview of the different types of gelatin-based structures including nanoparticles, microparticles, 3D scaffolds, electrospun nanofibers and in situ gelling formulations. Thanks to the significant progress that has already been made, along with others that will be achieved in a near future, the safe and effective clinical implementation of gelatin-based products is expected to accelerate and expand shortly. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

In Vivo Bio-distribution and Efficient Tumor Targeting of Gelatin/Silica Nanoparticles for Gene Delivery

NASA Astrophysics Data System (ADS)

Zhao, Xueqin; Wang, Jun; Tao, SiJie; Ye, Ting; Kong, Xiangdong; Ren, Lei

2016-04-01

The non-viral gene delivery system is an attractive alternative to cancer therapy. The clinical success of non-viral gene delivery is hampered by transfection efficiency and tumor targeting, which can be individually overcome by addition of functional modules such as cell penetration or targeting. Here, we first engineered the multifunctional gelatin/silica (GS) nanovectors with separately controllable modules, including tumor-targeting aptamer AGRO100, membrane-destabilizing peptide HA2, and polyethylene glycol (PEG), and then studied their bio-distribution and in vivo transfection efficiencies by contrast resonance imaging (CRI). The results suggest that the sizes and zeta potentials of multifunctional gelatin/silica nanovectors were 203-217 nm and 2-8 mV, respectively. Functional GS-PEG nanoparticles mainly accumulated in the liver and tumor, with the lowest uptake by the heart and brain. Moreover, the synergistic effects of tumor-targeting aptamer AGRO100 and fusogenic peptide HA2 promoted the efficient cellular internalization in the tumor site. More importantly, the combined use of AGRO100 and PEG enhanced tumor gene expression specificity and effectively reduced toxicity in reticuloendothelial system (RES) organs after intravenous injection. Additionally, low accumulation of GS-PEG was observed in the heart tissues with high gene expression levels, which could provide opportunities for non-invasive gene therapy.

Boronic acid-tethered amphiphilic hyaluronic acid derivative-based nanoassemblies for tumor targeting and penetration.

PubMed

Jeong, Jae Young; Hong, Eun-Hye; Lee, Song Yi; Lee, Jae-Young; Song, Jae-Hyoung; Ko, Seung-Hak; Shim, Jae-Seong; Choe, Sunghwa; Kim, Dae-Duk; Ko, Hyun-Jeong; Cho, Hyun-Jong

2017-04-15

(3-Aminomethylphenyl)boronic acid (AMPB)-installed hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated for tumor-targeted delivery. The amine group of AMPB was conjugated to the carboxylic acid group of hyaluronic acid (HA) via amide bond formation, and synthesis was confirmed by spectroscopic methods. HACE-AMPB/MB NPs with a 239-nm mean diameter, narrow size distribution, negative zeta potential, and >90% drug encapsulation efficiency were fabricated. Exposed AMPB in the outer surface of HACE-AMPB NPs (in the aqueous environment) may react with sialic acid of cancer cells. The improved cellular accumulation efficiency, in vitro antitumor efficacy, and tumor penetration efficiency of HACE-AMPB/MB NPs, compared with HACE/MB NPs, in MDA-MB-231 cells (CD44 receptor-positive human breast adenocarcinoma cells) may be based on the CD44 receptor-mediated endocytosis and phenylboronic acid-sialic acid interaction. Enhanced in vivo tumor targetability, infiltration efficiency, and antitumor efficacies of HACE-AMPB NPs, compared with HACE NPs, were observed in a MDA-MB-231 tumor-xenografted mouse model. In addition to passive tumor targeting (based on an enhanced permeability and retention effect) and active tumor targeting (interaction between HA and CD44 receptor), the phenylboronic acid-sialic acid interaction can play important roles in augmented tumor targeting and penetration of HACE-AMPB NPs. STATEMENT OF SIGNIFICANCE: (3-Aminomethylphenyl)boronic acid (AMPB)-tethered hyaluronic acid-ceramide (HACE)-based nanoparticles (NPs), including manassantin B (MB), were fabricated and their tumor targeting and penetration efficiencies were assessed in MDA-MB-231 (CD44 receptor-positive human adenocarcinoma) tumor models. MB, which exhibited antitumor efficacies via the inhibition of angiogenesis and hypoxia inducible factor (HIF)-1, was entrapped in HACE-AMPB NPs in this study. Phenylboronic acid located in the outer surface of HACE-AMPB/MB NPs (in the aqueous milieu) may react with the sialic acid over-expressed in cancer cells and intramolecular B‒O bond can be formed. This phenylboronic acid-sialic acid interaction may provide additional tumor targeting and penetration potentials together with an enhanced permeability and retention (EPR) effect (passive tumor targeting) and HA-CD44 receptor interaction (active tumor targeting). Developed HACE-AMPB NP may be one of promising nanocarriers for the imaging and therapy of CD44 receptor-expressed cancers. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Preparation and biocompatibility of a chitin nanofiber/gelatin composite film.

PubMed

Ogawa, Yoko; Azuma, Kazuo; Izawa, Hironori; Morimoto, Minoru; Ochi, Kosuke; Osaki, Tomohiro; Ito, Norihiko; Okamoto, Yoshiharu; Saimoto, Hiroyuki; Ifuku, Shinsuke

2017-11-01

The development of chitin-based materials with favorable mechanical properties and biocompatibility is an important research goal owing to the wide-ranging practical applications. In this study, a composite film was prepared using chitin nanofibers and gelatin. The CNF/gelatin composite film was highly viscous and had a fine nanofiber structure. The transmittances indicated high transparency, regardless of nanofiber content. The water content of the CNF/gelatin composite film increased linearly as the gelatin content increased. Although the CNF/gelatin composite film did not induce severe inflammation, it strongly induced fibroblast proliferation, indicating high biocompatibility. Based on these results, the films are suitable for biological applications, e.g., tissue engineering, medicines, and cosmetics. Copyright © 2017 Elsevier B.V. All rights reserved.

Report: Optimization study of the preparation factors for argan oil microcapsule based on hybrid-level orthogonal array design via SPSS modeling.

PubMed

Zhao, Xi; Wu, Xiaoli; Zhou, Hui; Jiang, Tao; Chen, Chun; Liu, Mingshi; Jin, Yuanbao; Yang, Dongsheng

2014-11-01

To optimize the preparation factors for argan oil microcapsule using complex coacervation of chitosan cross-linked with gelatin based on hybrid-level orthogonal array design via SPSS modeling. Eight relatively significant factors were firstly investigated and selected as calculative factors for the orthogonal array design from the total of ten factors effecting the preparation of argan oil microcapsule by utilizing the single factor variable method. The modeling of hybrid-level orthogonal array design was built in these eight factors with the relevant levels (9, 9, 9, 9, 7, 6, 2 and 2 respectively). The preparation factors for argan oil microcapsule were investigated and optimized according to the results of hybrid-level orthogonal array design. The priorities order and relevant optimum levels of preparation factors standard to base on the percentage of microcapsule with the diameter of 30~40 μm via SPSS. Experimental data showed that the optimum factors were controlling the chitosan/gelatin ratio, the systemic concentration and the core/shell ratio at 1:2, 1.5% and 1:7 respectively, presetting complex coacervation pH at 6.4, setting cross-linking time and complex coacervation at 75 min and 30 min, using the glucose-delta lactone as the type of cross-linking agent, and selecting chitosan with the molecular weight of 2000～3000.

Biodegradable protein-based rockets for drug transportation and light-triggered release.

PubMed

Wu, Zhiguang; Lin, Xiankun; Zou, Xian; Sun, Jianmin; He, Qiang

2015-01-14

We describe a biodegradable, self-propelled bovine serum albumin/poly-l-lysine (PLL/BSA) multilayer rocket as a smart vehicle for efficient anticancer drug encapsulation/delivery to cancer cells and near-infrared light controlled release. The rockets were constructed by a template-assisted layer-by-layer assembly of the PLL/BSA layers, followed by incorporation of a heat-sensitive gelatin hydrogel containing gold nanoparticles, doxorubicin, and catalase. These rockets can rapidly deliver the doxorubicin to the targeted cancer cell with a speed of up to 68 μm/s, through a combination of biocatalytic bubble propulsion and magnetic guidance. The photothermal effect of the gold nanoparticles under NIR irradiation enable the phase transition of the gelatin hydrogel for rapid release of the loaded doxorubicin and efficient killing of the surrounding cancer cells. Such biodegradable and multifunctional protein-based microrockets provide a convenient and efficient platform for the rapid delivery and controlled release of therapeutic drugs.

Molecular insights into shellac film coats from different aqueous shellac salt solutions and effect on disintegration of enteric-coated soft gelatin capsules.

PubMed

Al-Gousous, J; Penning, M; Langguth, P

2015-04-30

The purpose of this investigation was to study the effect of using different salts of shellac on the disintegration properties of shellac-based enteric coatings. In the last two decades, shellac has been increasingly used as an aqueous solution for enteric coating purposes, with the ammonium salt being the form typically used. Little investigation has been performed on using other salts, and therefore, this was the focus of our work. Enteric coatings, based on different shellac salts (ammonium, sodium, potassium and composite ammonium-sodium), were applied onto soft gelatin capsules. Disintegration testing of the coated soft gelatin capsules showed that alkali metal salts promote faster disintegration than ammonium salts. In order to determine the causes behind these differences, the solubility, thermal and spectroscopic properties of films cast from the different salts were investigated. The results show that films cast from ammonium-based salts of shellac are, unlike those cast from alkali metal-based salts, water-insoluble. Spectroscopic evidence suggests that this might be due to partial salt dissociation resulting in loss of ammonium as ammonia and reduced degree of shellac ionization during drying. In addition, oxidation of shellac aldehyde groups of the ammonium-based shellac salts could also play a role. And possible higher extent of shellac hydrolysis during the preparation of alkali metal salts might also be a factor. Therefore, the nature of the shellac salt used in the preparation of shellac-based aqueous coating solutions is a significant formulation factor affecting product performance. Copyright © 2014 Elsevier B.V. All rights reserved.

Structure- and reactivity-based development of covalent inhibitors of the activating and gatekeeper mutant forms of the epidermal growth factor receptor (EGFR).

PubMed

Ward, Richard A; Anderton, Mark J; Ashton, Susan; Bethel, Paul A; Box, Matthew; Butterworth, Sam; Colclough, Nicola; Chorley, Christopher G; Chuaqui, Claudio; Cross, Darren A E; Dakin, Les A; Debreczeni, Judit É; Eberlein, Cath; Finlay, M Raymond V; Hill, George B; Grist, Matthew; Klinowska, Teresa C M; Lane, Clare; Martin, Scott; Orme, Jonathon P; Smith, Peter; Wang, Fengjiang; Waring, Michael J

2013-09-12

A novel series of small-molecule inhibitors has been developed to target the double mutant form of the epidermal growth factor receptor (EGFR) tyrosine kinase, which is resistant to treatment with gefitinib and erlotinib. Our reported compounds also show selectivity over wild-type EGFR. Guided by molecular modeling, this series was evolved to target a cysteine residue in the ATP binding site via covalent bond formation and demonstrates high levels of activity in cellular models of the double mutant form of EGFR. In addition, these compounds show significant activity against the activating mutations, which gefitinib and erlotinib target and inhibition of which gives rise to their observed clinical efficacy. A glutathione (GSH)-based assay was used to measure thiol reactivity toward the electrophilic functionality of the inhibitor series, enabling both the identification of a suitable reactivity window for their potency and the development of a reactivity quantitative structure-property relationship (QSPR) to support design.

Physicochemical and antifungal properties of bio-nanocomposite film based on gelatin-chitin nanoparticles.

PubMed

Sahraee, Samar; Milani, Jafar M; Ghanbarzadeh, Babak; Hamishehkar, Hamed

2017-04-01

The gelatin-based nanocomposite films containing chitin nanoparticles (N-chitin) with concentrations of 0, 3, 5 and 10% were prepared and their physical, thermal and anti-microbial properties were investigated. Scanning electron microscopy (SEM) micrographs showed that N-chitin size distribution was around 60-70nm which dispersed appropriately at low concentration in gelatin matrix. The results showed that incorporation of N-chitin significantly influenced apparent color and transparency of the gelatin films. The reduced water vapor permeability (WVP) and solubility and higher surface hydrophobicity of the nanocomposite films were obtained by enhancing N-chitin concentration in film formulation. The use of N-chitin up to 5% concentration in the gelatin based nanocomposite film led to improved mechanical properties. Also, the results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) confirmed improved stability of nanocomposite films against melting and degradation at high temperatures in comparison to neat gelatin film. The well compatibility of chitin nanoparticles with gelatin polymer was concluded from Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) plots. Finally, the gelatin based nanocomposite films had anti-fungal properties against Aspergillus niger in the contact surface zone. Increasing the concentration of N-chitin up to 5% enlarged inhibition zone diameter, but the nanocomposite film containing 10% N-chitin showed smaller inhibition zone. Copyright © 2016 Elsevier B.V. All rights reserved.

Receptor-Mediated Uptake and Intracellular Sorting of Multivalent Lipid Nanoparticles Against the Epidermal Growth Factor Receptor (EGFR) and the Human EGFR 2 (HER2)

NASA Astrophysics Data System (ADS)

Tran, David Tu

In the area of receptor-targeted lipid nanoparticles for drug delivery, efficiency has been mainly focused on cell-specificity, endocytosis, and subsequently effects on bioactivity such as cell growth inhibition. Aspects of targeted liposomal uptake and intracellular sorting are not well defined. This dissertation assessed a series of ligands as targeted functional groups against HER2 and EGFR for liposomal drug delivery. Receptor-mediated uptake, both mono-targeted and dual-targeted to multiple receptors of different ligand valence, and the intracellular sorting of lipid nanoparticles were investigated to improve the delivery of drugs to cancer cells. Lipid nanoparticles were functionalized through a new sequential micelle transfer---conjugation method, while the micelle transfer method was extended to growth factors. Through a combination of both techniques, anti-HER2 and anti-EGFR dual-targeted immunoliposomes with different combinations of ligand valence were developed for comparative studies. With the array of lipid nanoparticles, the uptake and cytotoxicity of lipid nanoparticles in relationship to ligand valence, both mono-targeting and dual-targeting, were evaluated on a small panel of breast cancer cell lines that express HER2 and EGFR of varying levels. Comparable uptake ratios of ligand to expressed receptor and apparent cooperativity were observed. For cell lines that express both receptors, additive dose-uptake effects were also observed with dual-targeted immunoliposomes, which translated to marginal improvements in cell growth inhibition with doxorubicin delivery. Colocalization analysis revealed that ligand-conjugated lipid nanoparticles settle to endosomal compartments similar to their attached ligands. Pathway transregulation and pathway saturation were also observed to affect trafficking. In the end, liposomes routed to the recycling endosomes were never observed to traffic beyond the endosomes nor to be exocytose like recycled ligands. Based on the experimental data, models were developed to help interpret and predict the binding and trafficking of lipid nanoparticles. The crosslink multivalent binding model of lipid nanoparticles to monovalent receptors was able to predict ligand valence for optimum binding, cell association concentrations, offer explanations to the antagonistic effects observed from high ligand valence, and predict the binding limitations of both ligand valence and ligand affinity. Hopefully, the models will serve as valuable tools for future optimizations in targeted liposomal drug delivery.

New Molecular Targets of Anticancer Therapy - Current Status and Perspectives.

PubMed

Zajac, Marianna; Muszalska, Izabela; Jelinska, Anna

2016-01-01

Molecularly targeted anticancer therapy involves the use of drugs or other substances affecting specific molecular targets that play a part in the development, progression and spread of a given neoplasm. By contrast, the majority of classical chemotherapeutics act on all rapidly proliferating cells, both healthy and cancerous ones. Target anticancer drugs are designed to achieve a particular aim and they usually act cytostatically, not cytotoxically like classical chemotherapeutics. At present, more than 300 biological molecular targets have been identified. The proteins involved in cellular metabolism include (among others) receptor proteins, signal transduction proteins, mRNA thread matrix synthesis proteins participating in neoplastic transformation, cell cycle control proteins, functional and structural proteins. The receptor proteins that are targeted by currently used anticancer drugs comprise the epithelial growth factor receptor (EGFR), platelet-derived growth factor receptor (PDGFR) and vascular endothelial growth factor receptor(VEGFR). Target anticancer drugs may affect extracellular receptor domains (antibodies) or intracellular receptor domains (tyrosine kinase inhibitors). The blocking of the mRNA thread containing information about the structure of oncogenes (signal transduction proteins) is another molecular target of anticancer drugs. That type of treatment, referred to as antisense therapy, is in clinical trials. When the synthesis of genetic material is disturbed, in most cases the passage to the next cycle phase is blocked. The key proteins responsible for the blockage are cyclines and cycline- dependent kinases (CDK). Clinical trials are focused on natural and synthetic substances capable of blocking various CDKs. The paper discusses the molecular targets and chemical structure of target anticancer drugs that have been approved for and currently applied in antineoplastic therapy together with indications and contraindications for their application.

Embedded Ultrathin Cluster Electrodes for Long-Term Recordings in Deep Brain Centers

PubMed Central

Thorbergsson, Palmi Thor; Ekstrand, Joakim; Friberg, Annika; Granmo, Marcus; Pettersson, Lina M. E.; Schouenborg, Jens

2016-01-01

Neural interfaces which allow long-term recordings in deep brain structures in awake freely moving animals have the potential of becoming highly valuable tools in neuroscience. However, the recording quality usually deteriorates over time, probably at least partly due to tissue reactions caused by injuries during implantation, and subsequently micro-forces due to a lack of mechanical compliance between the tissue and neural interface. To address this challenge, we developed a gelatin embedded neural interface comprising highly flexible electrodes and evaluated its long term recording properties. Bundles of ultrathin parylene C coated platinum electrodes (N = 29) were embedded in a hard gelatin based matrix shaped like a needle, and coated with Kollicoat™ to retard dissolution of gelatin during the implantation. The implantation parameters were established in an in vitro model of the brain (0.5% agarose). Following a craniotomy in the anesthetized rat, the gelatin embedded electrodes were stereotactically inserted to a pre-target position, and after gelatin dissolution the electrodes were further advanced and spread out in the area of the subthalamic nucleus (STN). The performance of the implanted electrodes was evaluated under anesthesia, during 8 weeks. Apart from an increase in the median-noise level during the first 4 weeks, the electrode impedance and signal-to-noise ratio of single-units remained stable throughout the experiment. Histological postmortem analysis confirmed implantation in the area of STN in most animals. In conclusion, by combining novel biocompatible implantation techniques and ultra-flexible electrodes, long-term neuronal recordings from deep brain structures with no significant deterioration of electrode function were achieved. PMID:27159159

Micromixer Based Preparation of Functionalized Liposomes and Targeting Drug Delivery

PubMed Central

2016-01-01

We present here a specific targeting nanocarrier system by functionalization of liposomes with one new type of breast cancer targeting peptide (H6, YLFFVFER) by a micromixer with high efficiency. Antitumor drugs could be successfully delivered into human epidermal growth factor receptor 2 (HER2) positive breast cancer cells with high efficiency in both in vivo and ex vivo models. PMID:27096054

Stress transfer and matrix-cohesive fracture mechanism in microfibrillated cellulose-gelatin nanocomposite films.

PubMed

Quero, Franck; Padilla, Cristina; Campos, Vanessa; Luengo, Jorge; Caballero, Leonardo; Melo, Francisco; Li, Qiang; Eichhorn, Stephen J; Enrione, Javier

2018-09-01

Microfibrillated cellulose (MFC) obtained from eucalyptus was embedded in gelatin from two sources; namely bovine and salmon gelatin. Raman spectroscopy revealed that stress is transferred more efficiently from bovine gelatin to the MFC when compared to salmon gelatin. Young's modulus, tensile strength, strain at failure and work of fracture of the nanocomposite films were improved by ∼67, 131, 43 y 243% respectively when using salmon gelatin as matrix material instead of bovine gelatin. Imaging of the tensile fracture surface of the MFC-gelatin nanocomposites revealed that crack formation occurs predominantly within bovine and salmon gelatin matrices rather than within the MFC or at the MFC/gelatin interface. This suggests that the mechanical failure mechanism in these nanocomposite materials is predominantly governed by a matrix-cohesive fracture mechanism. Both strength and flexibility are desirable properties for composite coatings made from gelatin-based materials, and so the findings of this study could assist in their utilization in the food and pharmaceutical industry. Copyright © 2018 Elsevier Ltd. All rights reserved.

Gelatin device for the delivery of growth factors involved in endochondral ossification.

PubMed

Ahrens, Lucas A J; Vonwil, Daniel; Christensen, Jon; Shastri, V Prasad

2017-01-01

Controlled release drug delivery systems are well established as oral and implantable dosage forms. However, the controlled release paradigm can also be used to present complex soluble signals responsible for cellular organization during development. Endochondral ossification (EO), the developmental process of bone formation from a cartilage matrix is controlled by several soluble signals with distinct functions that vary in structure, molecular weight and stability. This makes delivering them from a single vehicle rather challenging. Herein, a gelatin-based delivery system suitable for the delivery of small molecules as well as recombinant human (rh) proteins (rhWNT3A, rhFGF2, rhVEGF, rhBMP4) is reported. The release behavior and biological activity of the released molecules was validated using analytical and biological assays, including cell reporter systems. The simplicity of fabrication of the gelatin device should foster its adaptation by the diverse scientific community interested in interrogating developmental processes, in vivo.

Gelatin device for the delivery of growth factors involved in endochondral ossification

PubMed Central

Ahrens, Lucas A. J.; Vonwil, Daniel; Christensen, Jon

2017-01-01

Controlled release drug delivery systems are well established as oral and implantable dosage forms. However, the controlled release paradigm can also be used to present complex soluble signals responsible for cellular organization during development. Endochondral ossification (EO), the developmental process of bone formation from a cartilage matrix is controlled by several soluble signals with distinct functions that vary in structure, molecular weight and stability. This makes delivering them from a single vehicle rather challenging. Herein, a gelatin-based delivery system suitable for the delivery of small molecules as well as recombinant human (rh) proteins (rhWNT3A, rhFGF2, rhVEGF, rhBMP4) is reported. The release behavior and biological activity of the released molecules was validated using analytical and biological assays, including cell reporter systems. The simplicity of fabrication of the gelatin device should foster its adaptation by the diverse scientific community interested in interrogating developmental processes, in vivo. PMID:28380024

Gelatin Methacrylate Microspheres for Growth Factor Controlled Release

PubMed Central

Nguyen, Anh H.; McKinney, Jay; Miller, Tobias; Bongiorno, Tom; McDevitt, Todd C.

2014-01-01

Gelatin has been commonly used as a delivery vehicle for various biomolecules for tissue engineering and regenerative medicine applications due to its simple fabrication methods, inherent electrostatic binding properties, and proteolytic degradability. Compared to traditional chemical cross-linking methods, such as the use of glutaraldehyde (GA), methacrylate modification of gelatin offers an alternative method to better control the extent of hydrogel cross-linking. Here we examined the physical properties and growth factor delivery of gelatin methacrylate (GMA) microparticles formulated with a wide range of different cross-linking densities (15–90%). Less methacrylated MPs had decreased elastic moduli and larger mesh sizes compared to GA MPs, with increasing methacrylation correlating to greater moduli and smaller mesh sizes. As expected, an inverse correlation between microparticle cross-linking density and degradation was observed, with the lowest cross-linked GMA MPs degrading at the fastest rate, comparable to GA MPs. Interestingly, GMA MPs at lower cross-linking densities could be loaded with up to a 10-fold higher relative amount of growth factor over conventional GA cross-linked MPs, despite an order of magnitude greater gelatin content of GA MPs. Moreover, a reduced GMA cross-linking density resulted in more complete release of bone morphogenic protein 4 (BMP4) and basic fibroblast growth factor (bFGF) and accelerated release rate with collagenase treatment. These studies demonstrate that GMA MPs provide a more flexible platform for growth factor delivery by enhancing the relative binding capacity and permitting proteolytic degradation tunability, thereby offering a more potent controlled release system for growth factor delivery. PMID:25463489

Discovery of Novel Human Epidermal Growth Factor Receptor-2 Inhibitors by Structure-based Virtual Screening.

PubMed

Shi, Zheng; Yu, Tian; Sun, Rong; Wang, Shan; Chen, Xiao-Qian; Cheng, Li-Jia; Liu, Rong

2016-01-01

Human epidermal growth factor receptor-2 (HER2) is a trans-membrane receptor like protein, and aberrant signaling of HER2 is implicated in many human cancers, such as ovarian cancer, gastric cancer, and prostate cancer, most notably breast cancer. Moreover, it has been in the spotlight in the recent years as a promising new target for therapy of breast cancer. Since virtual screening has become an integral part of the drug discovery process, it is of great significant to identify novel HER2 inhibitors by structure-based virtual screening. In this study, we carried out a series of elegant bioinformatics approaches, such as virtual screening and molecular dynamics (MD) simulations to identify HER2 inhibitors from Food and Drug Administration-approved small molecule drug as potential "new use" drugs. Molecular docking identified top 10 potential drugs which showed spectrum affinity to HER2. Moreover, MD simulations suggested that ZINC08214629 (Nonoxynol-9) and ZINC03830276 (Benzonatate) might exert potential inhibitory effects against HER2-targeted anti-breast cancer therapeutics. Together, our findings may provide successful application of virtual screening studies in the lead discovery process, and suggest that our discovered small molecules could be effective HER2 inhibitor candidates for further study. A series of elegant bioinformatics approaches, including virtual screening and molecular dynamics (MD) simulations were took advantage to identify human epidermal growth factor receptor-2 (HER2) inhibitors. Molecular docking recognized top 10 candidate compounds, which showed spectrum affinity to HER2. Further, MD simulations suggested that ZINC08214629 (Nonoxynol-9) and ZINC03830276 (Benzonatate) in candidate compounds were identified as potential "new use" drugs against HER2-targeted anti-breast cancer therapeutics. Abbreviations used: HER2: Human epidermal growth factor receptor-2, FDA: Food and Drug Administration, PDB: Protein Database Bank, RMSDs: Root mean square deviations, SPC: Single point charge, PME: Particle mesh Ewald, NVT: Constant volume, NPT: Constant pressure, RMSF: Root-mean-square fluctuation.

Selection of a chitosan gelatin-based edible coating for color preservation of beef in retail display.

PubMed

Cardoso, Giselle Pereira; Dutra, Monalisa Pereira; Fontes, Paulo Rogério; Ramos, Alcinéia de Lemos Souza; Gomide, Lúcio Alberto de Miranda; Ramos, Eduardo Mendes

2016-04-01

Chitosan gelatin-based coating films were applied to beef steaks, and their effects on color preservation and lipid oxidation during retail display were evaluated. Response surface methodology was used to model and describe the effects of different biopolymer concentrations (0 to 6% gelatin; 0.5 to 1.5% chitosan; and 0 to 12% glycerol based on dry gelatin+chitosan weight) in the coating film for optimizing the best combination for meat application. Film application reduced weight loss and lipid oxidation of the steaks after 5 days of storage, and films with higher gelatin concentrations were more effective. The percentage levels of different myoglobin-redox forms were not affected by coating, but myoglobin oxidation during retail display was reduced and the percentage of deoxymyoglobin increased with the gelatin content of the film. Steak color stability during retail display was promoted by film application; the steaks exhibited a darker, more intensely red color when coated in blends with higher gelatin and chitosan contents. Blends containing between 3% and 6% gelatin, between 0.5% and 1.0% chitosan and 6% glycerol exhibited the best results and provide a promising alternative to the preservation of beef in retail display. Copyright © 2015 Elsevier Ltd. All rights reserved.

Properties of active gelatin films incorporated with rutin-loaded nanoemulsions.

PubMed

Dammak, Ilyes; de Carvalho, Rosemary Aparecida; Trindade, Carmen Sílvia Fávaro; Lourenço, Rodrigo Vinicius; do Amaral Sobral, Paulo José

2017-05-01

Physico-chemical, mechanical, barrier, release profiles and antioxidant properties of composite gelatin based-films incorporated with rutin-loaded oil-in-water nanoemulsion, at various concentrations (5, 10, 15, or 20% (based on the weight of the gelatin powder)) were studied. All the gelatin/rutin-loaded nanoemulsion films displayed higher tensile strength and higher elongation at break than the gelatin control film. The composite films did not show significant differences in thickness, color, brightness and transparency. The structural properties evaluated by FTIR showed that the rutin-loaded nanoemulsion achieved complete miscibility within the gelatin matrix. All the gelatin/nanoemulsion films exhibited compact and homogenous microstructure. In addition, these films showed high antioxidant activities monitored by DPPH radical scavenging and reducing power activities. The Korsmeyer-Peppas model described well the rutin release profile. Rutin release was mainly governed by Fickian diffusion with simultaneous interfering swelling and disintegration phenomena. These results indicate that nanoemulsions-in-gelatin systems can function as potential active packaging systems to enhance shelf life of food products and then to provide a high-quality products (fresh/safe). Copyright © 2017 Elsevier B.V. All rights reserved.

Urticaria following varicella vaccine associated with gelatin allergy.

PubMed

Singer, S; Johnson, C E; Mohr, R; Holowecky, C

1999-01-28

An uncommon reaction to varicella vaccine has been urticaria. Based on two reports of urticaria believed to be due to gelatin in recipients of measles-mumps-rubella vaccine, we suspected gelatin as the cause of generalized urticaria in two children after varicella vaccination. Intradermal testing with gelatin yielded a wheal and flare reaction in both children. We conclude that children known to be allergic to gelatin should not receive Oka/Merck varicella vaccine (VARIVAX).

Using the interplay of magnetic guidance and controlled TGF-β release from protein-based nanocapsules to stimulate chondrogenesis.

PubMed

Chiang, Chih-Sheng; Chen, Jian-Yi; Chiang, Min-Yu; Hou, Kai-Ting; Li, Wei-Ming; Chang, Shwu-Jen; Chen, San-Yuan

2018-01-01

Stimulating the proliferation and differentiation of chondrocytes for the regeneration of articular cartilage is a promising strategy, but it is currently ineffective. Although both physical stimulation and growth factors play important roles in cartilage repair, their interplay remains unclear and requires further investigation. In this study, we aimed to clarify their contribution using a magnetic drug carrier that not only can deliver growth factors but also provide an external stimulation to cells in the two-dimensional environment. We developed a nanocapsule (transforming growth factor-β1 [TGF-β1]-loaded magnetic amphiphilic gelatin nanocapsules [MAGNCs]; TGF-β1@MAGNCs) composed of hexanoic-anhydride-grafted gelatin and iron oxide nanoparticles to provide a combination treatment of TGF-β1 and magnetically induced physical stimuli. With the expression of Arg-Gly-Asp peptide in the gelatin, the TGF-β1@MAGNCs have an inherent affinity for chondrogenic ATDC5 cells. In the absence of TGF-β1, ATDC5 cells treated with a magnetic field show significantly upregulated Col2a1 expression. Moreover, TGF-β1 slowly released from biodegradable TGF-β1@ MAGNCs further improves the differentiation with increased expression of Col2a1 and Aggrecan. Our study shows the time-dependent interplay of physical stimuli and growth factors on chondrogenic regeneration, and demonstrates the promising use of TGF-β1@MAGNCs for articular cartilage repair.

Myelin basic protein immunosensor for multiple sclerosis detection based upon label-free electrochemical impedance spectroscopy.

PubMed

Derkus, Burak; Emregul, Emel; Yucesan, Canan; Cebesoy Emregul, Kaan

2013-08-15

A novel highly sensitive impedimetric Myelin Basic Protein (MBP) immunosensor for the determination of a Multiple Sclerosis (MS) autoantibody, Anti-Myelin Basic Protein (Anti-MBP) was developed by immobilization of MBP on Gelatin and Gelatin-Titanium Dioxide (TiO₂) modified platinium electrode. Cyclic voltammetric (CV) and Electrochemical Impedance Spectroscopic (EIS) methods were employed in determination of the electrode responses and applicability. Gelatin-MBP and gelatin-TiO₂-MBP electrodes were prepared by chemical immobilization of the substrates onto the platinium electrodes. The formal potentials of MBP confined on gelatin-MBP and gelatin-TiO₂-MBP surfaces are estimated to be 195 and 205 mV, respectively. Thus, a little more reversible electron transfer reaction occurs on the gelatin-TiO₂-MBP immunosensor surface. The peak separations of MBP (150 mV and 110 mV s(-1) at 100 mV s(-1)) and the asymmetric anodic and cathodic peak currents indicate that the electron transfer between Anti-MBP and gelatin-MBP/gelatin-TiO₂-MBP immunosensor is quasireversible. Control samples containing a nonspecific human immunoglobulin G (hIgG) antibody were also studied, and calibration curves were obtained by subtraction of the responses for specific and nonspecific antibody-based sensors. Gelatin-MBP and gelatin-TiO₂-MBP immunosensors have detection limit of 0.1528 ng ml(-1) and 0.1495 ng ml(-1) respectively. This immunosensor exhibits high sensitivity and low response times (58 s for gelatin-MBP and 46 s for gelatin-TiO₂-MBP immunosensor). The developed label-free impedimetric immunosensors also provide a simple and sensitive detection method for the specific determination of Anti-MBP in human cerebrospinal fluid (CSF) and serum samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Quantification of cell surface receptor expression in live tissue culture media using a dual-tracer stain and rinse approach

NASA Astrophysics Data System (ADS)

Xu, Xiaochun; Sinha, Lagnojita; Singh, Aparna; Yang, Cynthia; Xiang, Jialing; Tichauer, Kenneth M.

2015-03-01

Immunofluorescence staining is a robust way to visualize the distribution of targeted biomolecules invasively in in fixed tissues and tissue culture. Despite the fact that these methods has been a well-established method in fixed tissue imaging for over 70 years, quantification of receptor concentration still simply assumes that the signal from the targeted fluorescent marker after incubation and sufficient rinsing is directly proportional to the concentration of targeted biomolecules, thus neglecting the experimental inconsistencies in incubation and rinsing procedures and assuming no, nonspecific binding of the fluorescent markers. This work presents the first imaging approach capable of quantifying the concentration of cell surface receptor on cancer cells grown in vitro based on compartment modeling in a nondestructive way. The approach utilizes a dual-tracer protocol where any non-specific retention or variability in incubation and rinsing of a receptor-targeted imaging agent is corrected by simultaneously imaging the retention of a chemically similar, "untargeted" imaging agent. Various different compartment models were used to analyze the data in order to find the optimal procedure for extracting estimates of epidermal growth factor receptor (EGFR) concentration (a receptor overexpressed in many cancers and a key target for emerging molecular therapies) in tissue cultures with varying concentrations of human glioma cells (U251). Preliminary results demonstrated a need to model nonspecific binding of both the targeted and untargeted imaging agents used. The approach could be used to carry out the first repeated measures of cell surface receptor dynamics during 3D tumor mass development, in addition to the receptor response to therapies.

Structural insights into pharmacophore-assisted in silico identification of protein-protein interaction inhibitors for inhibition of human toll-like receptor 4 - myeloid differentiation factor-2 (hTLR4-MD-2) complex.

PubMed

Mishra, Vinita; Pathak, Chandramani

2018-05-29

Toll-like receptor 4 (TLR4) is a member of Toll-Like Receptors (TLRs) family that serves as a receptor for bacterial lipopolysaccharide (LPS). TLR4 alone cannot recognize LPS without aid of co-receptor myeloid differentiation factor-2 (MD-2). Binding of LPS with TLR4 forms a LPS-TLR4-MD-2 complex and directs downstream signaling for activation of immune response, inflammation and NF-κB activation. Activation of TLR4 signaling is associated with various pathophysiological consequences. Therefore, targeting protein-protein interaction (PPI) in TLR4-MD-2 complex formation could be an attractive therapeutic approach for targeting inflammatory disorders. The aim of present study was directed to identify small molecule PPI inhibitors (SMPPIIs) using pharmacophore mapping-based approach of computational drug discovery. Here, we had retrieved the information about the hot spot residues and their pharmacophoric features at both primary (TLR4-MD-2) and dimerization (MD-2-TLR4*) protein-protein interaction interfaces in TLR4-MD-2 homo-dimer complex using in silico methods. Promising candidates were identified after virtual screening, which may restrict TLR4-MD-2 protein-protein interaction. In silico off-target profiling over the virtually screened compounds revealed other possible molecular targets. Two of the virtually screened compounds (C11 and C15) were predicted to have an inhibitory concentration in μM range after HYDE assessment. Molecular dynamics simulation study performed for these two compounds in complex with target protein confirms the stability of the complex. After virtual high throughput screening we found selective hTLR4-MD-2 inhibitors, which may have therapeutic potential to target chronic inflammatory diseases.

Defective lysosomal targeting of activated fibroblast growth factor receptor 3 in achondroplasia.

PubMed

Cho, Jay Y; Guo, Changsheng; Torello, Monica; Lunstrum, Gregory P; Iwata, Tomoko; Deng, Chuxia; Horton, William A

2004-01-13

Mutations of fibroblast growth factor receptor 3 (FGFR3) are responsible for achondroplasia (ACH) and related dwarfing conditions in humans. The pathogenesis involves constitutive activation of FGFR3, which inhibits proliferation and differentiation of growth plate chondrocytes. Here we report that activating mutations in FGFR3 increase the stability of the receptor. Our results suggest that the mutations disrupt c-Cbl-mediated ubiquitination that serves as a targeting signal for lysosomal degradation and termination of receptor signaling. The defect allows diversion of actively signaling receptors from lysosomes to a recycling pathway where their survival is prolonged, and, as a result, their signaling capacity is increased. The lysosomal targeting defect is additive to other mechanisms proposed to explain the pathogenesis of ACH.

2D and 3D Matrices to Study Linear Invadosome Formation and Activity.

PubMed

Di Martino, Julie; Henriet, Elodie; Ezzoukhry, Zakaria; Mondal, Chandrani; Bravo-Cordero, Jose Javier; Moreau, Violaine; Saltel, Frederic

2017-06-02

Cell adhesion, migration, and invasion are involved in many physiological and pathological processes. For example, during metastasis formation, tumor cells have to cross anatomical barriers to invade and migrate through the surrounding tissue in order to reach blood or lymphatic vessels. This requires the interaction between cells and the extracellular matrix (ECM). At the cellular level, many cells, including the majority of cancer cells, are able to form invadosomes, which are F-actin-based structures capable of degrading ECM. Invadosomes are protrusive actin structures that recruit and activate matrix metalloproteinases (MMPs). The molecular composition, density, organization, and stiffness of the ECM are crucial in regulating invadosome formation and activation. In vitro, a gelatin assay is the standard assay used to observe and quantify invadosome degradation activity. However, gelatin, which is denatured collagen I, is not a physiological matrix element. A novel assay using type I collagen fibrils was developed and used to demonstrate that this physiological matrix is a potent inducer of invadosomes. Invadosomes that form along the collagen fibrils are known as linear invadosomes due to their linear organization on the fibers. Moreover, molecular analysis of linear invadosomes showed that the discoidin domain receptor 1 (DDR1) is the receptor involved in their formation. These data clearly demonstrate the importance of using a physiologically relevant matrix in order to understand the complex interactions between cells and the ECM.

Influence of lyophilization factors and gelatin concentration on pore structures of atelocollagen/gelatin sponge biomaterial.

PubMed

Yang, Longqiang; Tanabe, Koji; Miura, Tadashi; Yoshinari, Masao; Takemoto, Shinji; Shintani, Seikou; Kasahara, Masataka

2017-07-26

This study aimed to investigate influences of lyophilization factors and gelatin concentration on pore structures of ACG sponge. ACG sponges of different freezing temperatures (-30, -80 and -196 o C), freezing times (1, 2 and 24 h), gelatin concentrations (0.6%AC+0.15%G, 0.6%AC+0.6%G and 0.6%AC+2.4%G), and with 500 μM fluvastatin were fabricated. Pore structures including porosity and pore size were analyzed by scanning electron microscopy and ImageJ. The cytotoxic effects of ACG sponges were evaluated in vitro. Freezing temperature did not affect porosity while high freezing temperature (-30 o C) increased pore size. The high gelatin concentration group (0.6%AC+2.4%G) had decreased porosity and pore size. Freezing time and 500 μM fluvastatin did not affect pore structures. The cytotoxicity and cell proliferation assays revealed that ACG sponges had no cytotoxic effects on human mesenchymal stromal cell growth and proliferation. These results indicate that ACG sponge may be a good biomaterial scaffold for bone regeneration.

Improved decision making for prioritizing tumor targeting antibodies in human xenografts: Utility of fluorescence imaging to verify tumor target expression, antibody binding and optimization of dosage and application schedule.

PubMed

Dobosz, Michael; Haupt, Ute; Scheuer, Werner

2017-01-01

Preclinical efficacy studies of antibodies targeting a tumor-associated antigen are only justified when the expression of the relevant antigen has been demonstrated. Conventionally, antigen expression level is examined by immunohistochemistry of formalin-fixed paraffin-embedded tumor tissue section. This method represents the diagnostic "gold standard" for tumor target evaluation, but is affected by a number of factors, such as epitope masking and insufficient antigen retrieval. As a consequence, variances and discrepancies in histological staining results can occur, which may influence decision-making and therapeutic outcome. To overcome these problems, we have used different fluorescence-labeled therapeutic antibodies targeting human epidermal growth factor receptor (HER) family members and insulin-like growth factor-1 receptor (IGF1R) in combination with fluorescence imaging modalities to determine tumor antigen expression, drug-target interaction, and biodistribution and tumor saturation kinetics in non-small cell lung cancer xenografts. For this, whole-body fluorescence intensities of labeled antibodies, applied as a single compound or antibody mixture, were measured in Calu-1 and Calu-3 tumor-bearing mice, then ex vivo multispectral tumor tissue analysis at microscopic resolution was performed. With the aid of this simple and fast imaging method, we were able to analyze the tumor cell receptor status of HER1-3 and IGF1R, monitor the antibody-target interaction and evaluate the receptor binding sites of anti-HER2-targeting antibodies. Based on this, the most suitable tumor model, best therapeutic antibody, and optimal treatment dosage and application schedule was selected. Predictions drawn from obtained imaging data were in excellent concordance with outcome of conducted preclinical efficacy studies. Our results clearly demonstrate the great potential of combined in vivo and ex vivo fluorescence imaging for the preclinical development and characterization of monoclonal antibodies.

Vascular endothelial growth factor (VEGF) inhibition--a critical review.

PubMed

Moreira, Irina Sousa; Fernandes, Pedro Alexandrino; Ramos, Maria João

2007-03-01

Angiogenesis, or formation of new blood capillaries from preexisting vessels, plays both beneficial and damaging roles in the organism. It is a result of a complex balance of positive and negative regulators, and vascular endothelial growth factor (VEGF) is one of the most important pro-angiogenic factors involved in tumor angiogenesis. VEGF increases vascular permeability, which might facilitate tumor dissemination via the circulation causing a greater delivery of oxygen and nutrients; it recruits circulating endothelial precursor cells, and acts as a survival factor for immature tumor blood vessels. The endotheliotropic activities of VEGF are mediated through the VEGF-specific tyrosine-kinase receptors: VEGFR-1, VEGFR-2 and VEGFR-3. VEGF and its receptors play a central role in tumor angiogenesis, and therefore the blockade of this pathway is a promising therapeutic strategy for inhibiting angiogenesis and tumor growth. A number of different strategies to inhibit VEGF signal transduction are in development and they include the development of humanized neutralizing anti-VEGF monoclonal antibodies, receptor antagonists, soluble receptors, antagonistic VEGF mutants, and inhibitors of VEGF receptor function. These agents can be divided in two broad classes, namely agents designed to target the VEGF activity and agents designed to target the surface receptor function. The main purpose of this review is to summarize all the available information regarding the importance of the pro-angiogenic factor VEGF in cancer therapy. After an overview of the VEGF family and their respective receptors, we shall focus our attention on the different VEGF-inhibitors existent nowadays. Agents based upon anti-VEGF therapy have provided solid proofs about their success, and therefore we believe that a critical review is of the utmost importance to help researchers in their future work.

Targeted therapies in the treatment of urothelial cancers.

PubMed

Aragon-Ching, Jeanny B; Trump, Donald L

2017-07-01

Progress has been slow in systemic management of locally advanced and metastatic bladder cancer over the past 20 years. However, the recent approval of immunotherapy with atezolizumab and nivolumab for second-line salvage therapy may usher in an era of more rapid improvement. Systemic treatment is suboptimal and is an area of substantial unmet medical need. The recent findings from The Cancer Genome Atlas project revealed promising pathways that may be amenable to targeted therapies. Promising results with treatment using vascular endothelial growth factor inhibitors such as ramucirumab, sunitinib or bevacizumab, and human epidermal growth factor receptor 2 targeted therapies, epidermal growth factor receptor inhibitors, and fibroblast growth factor receptor inhibitors, are undergoing clinical trials and are discussed later. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaporation-based method for preparing gelatin foams with aligned tubular pore structures.

PubMed

Frazier, Shane D; Srubar, Wil V

2016-05-01

Gelatin-based foams with aligned tubular pore structures were prepared via liquid-to-gas vaporization of tightly bound water in dehydrated gelatin hydrogels. This study elucidates the mechanism of the foaming process by investigating the secondary (i.e., helical) structure, molecular interactions, and water content of gelatin films before and after foaming using X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. Experimental data from gelatin samples prepared at various gelatin-to-water concentrations (5-30 wt.%) substantiate that resulting foam structures are similar in pore diameter (approximately 350 μm), shape, and density (0.05-0.22 g/cm(3)) to those fabricated using conventional methods (e.g., freeze-drying). Helical structures were identified in the films but were not evident in the foamed samples after vaporization (~150 °C), suggesting that the primary foaming mechanism is governed by the vaporization of water that is tightly bound in secondary structures (i.e., helices, β-turns, β-sheets) that are present in dehydrated gelatin films. FTIR and TGA data show that the foaming process leads to more disorder and reduced hydrogen bonding to hydroxyl groups in gelatin and that no thermal degradation of gelatin occurs before or after foaming. Copyright © 2016 Elsevier B.V. All rights reserved.

Architectural and Mechanical Cues Direct Mesenchymal Stem Cell Interactions with Crosslinked Gelatin Scaffolds

PubMed Central

McAndrews, Kathleen M.; Kim, Min Jeong; Lam, Tuyet Y.; McGrail, Daniel J.

2014-01-01

Naturally derived biomaterials have emerged as modulators of cell function and tissue substitutes. Here, we developed crosslinked glutaraldehyde (GTA) scaffolds for the expansion and differentiation of mesenchymal stem cells (MSCs). The mechanical and architectural properties of the scaffolds were altered by varying the concentration of gelatin and GTA. Higher GTA concentrations were associated with an increase in more confined pores and osteogenic differentiation. In addition, myogenic potential varied with crosslinking degree, although bulk mechanical properties were unaltered. Correlation analysis revealed that ALP activity of differentiated MSCs on higher gelatin concentration scaffolds was dependent on traditional effectors, including environment elasticity and spread area. In contrast, the differentiation capacity of cells cultured on lower gelatin concentration scaffolds did not correlate with these factors, instead it was dependent on the hydrated pore structure. These results suggest that scaffold composition can determine what factors direct differentiation and may have critical implications for biomaterial design. PMID:24873687

A live zebrafish-based screening system for human nuclear receptor ligand and cofactor discovery.

PubMed

Tiefenbach, Jens; Moll, Pamela R; Nelson, Meryl R; Hu, Chun; Baev, Lilia; Kislinger, Thomas; Krause, Henry M

2010-03-22

Nuclear receptors (NRs) belong to a superfamily of transcription factors that regulate numerous homeostatic, metabolic and reproductive processes. Taken together with their modulation by small lipophilic molecules, they also represent an important and successful class of drug targets. Although many NRs have been targeted successfully, the majority have not, and one third are still orphans. Here we report the development of an in vivo GFP-based reporter system suitable for monitoring NR activities in all cells and tissues using live zebrafish (Danio rerio). The human NR fusion proteins used also contain a new affinity tag cassette allowing the purification of receptors with bound molecules from responsive tissues. We show that these constructs 1) respond as expected to endogenous zebrafish hormones and cofactors, 2) facilitate efficient receptor and cofactor purification, 3) respond robustly to NR hormones and drugs and 4) yield readily quantifiable signals. Transgenic lines representing the majority of human NRs have been established and are available for the investigation of tissue- and isoform-specific ligands and cofactors.

Identification of estrogen-responsive genes using a genome-wide analysis of promoter elements for transcription factor binding sites.

PubMed

Kamalakaran, Sitharthan; Radhakrishnan, Senthil K; Beck, William T

2005-06-03

We developed a pipeline to identify novel genes regulated by the steroid hormone-dependent transcription factor, estrogen receptor, through a systematic analysis of upstream regions of all human and mouse genes. We built a data base of putative promoter regions for 23,077 human and 19,984 mouse transcripts from National Center for Biotechnology Information annotation and 8793 human and 6785 mouse promoters from the Data Base of Transcriptional Start Sites. We used this data base of putative promoters to identify potential targets of estrogen receptor by identifying estrogen response elements (EREs) in their promoters. Our program correctly identified EREs in genes known to be regulated by estrogen in addition to several new genes whose putative promoters contained EREs. We validated six genes (KIAA1243, NRIP1, MADH9, NME3, TPD52L, and ABCG2) to be estrogen-responsive in MCF7 cells using reverse transcription PCR. To allow for extensibility of our program in identifying targets of other transcription factors, we have built a Web interface to access our data base and programs. Our Web-based program for Promoter Analysis of Genome, PAGen@UIC, allows a user to identify putative target genes for vertebrate transcription factors through the analysis of their upstream sequences. The interface allows the user to search the human and mouse promoter data bases for potential target genes containing one or more listed transcription factor binding sites (TFBSs) in their upstream elements, using either regular expression-based consensus or position weight matrices. The data base can also be searched for promoters harboring user-defined TFBSs given as a consensus or a position weight matrix. Furthermore, the user can retrieve putative promoter sequences for any given gene together with identified TFBSs located on its promoter. Orthologous promoters are also analyzed to determine conserved elements.

Morphology, orientation, and mechanical properties of gelatin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanton, T.N.; Tsou, A.H.

1996-12-31

Gelatin is a polypeptide derived from degradation and disorganization of collagen fibers and is the primary binder in photographic emulsions. Gelatin provides the mechanical integrity and strength to the photographic emulsion allowing for packaging, handling, and photofinishing operations. Gelatin films generated from aqueous-solution casting can exist in a semicrystalline or an amorphous state. When a gelatin solution is cooled below its helix-coil transition temperature, partial renaturation of gelatin to form triple helices can occur. The degree of renaturation in a coated film is dependent upon the drying temperature and the drying rate. During the drying process, gelatin crystals can bemore » formed by lateral association of the triple helices through a mechanism of nucleation and growth of a fringed micelle structure. X-ray scattering techniques have been utilized to examine the morphology and orientation of gelatin films. Based on X-ray diffraction data, it is observed that aggregates of triple-helix rods lie parallel to the film plane but are symmetrically distributed within the film plane. Since a material`s physical and mechanical properties are related to its structure, it is necessary to understand and to characterize the morphological development in gelatin film formation. In this study, an X-ray diffractometer and pole figure goniometer were utilized to examine the structural development and orientation anisotropy in solid-state gelatin films. Also, in this study, the in-plane mechanical properties of a gelatin film were determined from a uniaxial tensile test, and the gelatin film properties in the thickness direction were extracted from an indentation test based on the finite element analysis of the indentation results using a viscoelastic material model.« less

Efficient Purification and Release of Circulating Tumor Cells by Synergistic Effect of Biomarker and SiO2 @Gel-Microbead-Based Size Difference Amplification.

PubMed

Huang, Qinqin; Cai, Bo; Chen, Bolei; Rao, Lang; He, Zhaobo; He, Rongxiang; Guo, Feng; Zhao, Libo; Kondamareddy, Kiran Kumar; Liu, Wei; Guo, Shishang; Zhao, Xing-Zhong

2016-07-01

Microfluidics-based circulating tumor cell (CTC) isolation is achieved by using gelatin-coated silica microbeads conjugated to CTC-specific antibodies. Bead-binding selectively enlarges target cell size, providing efficient high-purity capture. CTCs captured can be further released non-invasively. This stratagem enables high-performance CTC isolation for subsequent studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Angiogenic effect of platelet-rich plasma combined with gelatin hydrogel granules injected into murine subcutis.

PubMed

Kakudo, Natsuko; Morimoto, Naoki; Ogawa, Takeshi; Hihara, Masakatsu; Notodihardjo, Priscilla Valentin; Matsui, Makoto; Tabata, Yasuhiko; Kusumoto, Kenji

2017-07-01

Platelet-rich plasma (PRP), which contains highly concentrated platelets, is produced by centrifuging whole blood. It is a safe and readily available source of a wide range of growth factors necessary for angiogenesis. Gelatin hydrogel granules have been designed and prepared for the controlled release of many growth factors. The angiogenic effect of human PRP was examined in vitro, and the effect of its subcutaneous injection with gelatin hydrogel granules into murine subcutis was evaluated. Human PRP was prepared using a double-spin method. The concentration of growth factors and the platelet count were examined in PRP and in vitro, and the angiogenic activity of human umbilical vein endothelial cells (HUVECs) in co-culture with human dermal fibroblast cells (NHDFs) in the presence and absence of PRP was evaluated. Then, in vivo, PRP, either free or with gelatin hydrogel granules, was injected subcutaneously into tiebacks on mice. Using a microscope and Kurabo angiogenesis image analyser software, the area containing newly formed capillaries was evaluated histologically and the microvascular network score was calculated. PRP was shown to contain high concentrations of PDGF, VEGF and TGFβ and had an angiogenic effect on the co-culture system. PRP with gelatin hydrogel granules significantly enlarged the area containing newly formed capillaries and promoted the microvascular network in murine subcutaneous tissue. PRP encapsulated in gelatin hydrogel microspheres shows promise for enhancing angiogenic effects in murine subcutis and could represent a potential therapeutic combination for the treatment of ischaemic disorders. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Sequential delivery of BMP-2 and IGF-1 using a chitosan gel with gelatin microspheres enhances early osteoblastic differentiation

PubMed Central

Kim, Sungwoo; Kang, Yunqing; Krueger, Chad A.; Sen, Milan; Holcomb, John B.; Chen, Di; Wenke, Joseph C.; Yang, Yunzhi

2012-01-01

The purpose of this study was to develop and characterize a chitosan gel/gelatin microspheres (MSs) dual delivery system for sequential release of bone morphogenetic protein-2 (BMP-2) and insulin-like growth factor-1 (IGF-1) to enhance osteoblast differentiation in vitro. We made and characterized the delivery system based on its degree of cross-linking, degradation, and release kinetics. We also evaluated the cytotoxicity of the delivery system and the effect of growth factors on cell response using pre-osteoblast W-20-17 mouse bone marrow stromal cells. IGF-1 was first loaded into MSs, and then the IGF-1 containing MSs were encapsulated into the chitosan gel which contained BMP-2. Cross-linking of gelatin with glyoxal via Schiff bases significantly increased thermal stability and decreased the solubility of the MSs, leading to a significant decrease in the initial release of IGF-1. Encapsulation of the MSs into the chitosan gel generated polyelectrolyte complexes by intermolecular interactions, which further affected the release kinetics of IGF-1. This combinational delivery system provided an initial release of BMP-2 followed by a slow and sustained release of IGF-1. Significantly greater alkaline phosphatase activity was found in W-20-17 cells treated with the sequential delivery system than other treatments (p<0.05) after a week of culture. PMID:22293583

Preparation and characterization of oxybenzone-loaded gelatin microspheres for enhancement of sunscreening efficacy.

PubMed

Patel, M; Jain, Sunil K; Yadav, Awesh K; Gogna, D; Agrawal, G P

2006-01-01

The objective of our present study was to prepare and evaluate gelatin microspheres of oxybenzone to enhance its sunscreening efficacy. The gelatin microspheres of oxybenzone were prepared by emulsion method. Process parameters were analyzed to optimize the formulation. The in vitro drug release study was performed in pH 7.4 using cellulose acetate membrane. Microspheres prepared using oxybenzone:gelatin ratio of 1:6 showed slowest drug release and those prepared with oxybenzone:gelatin ratio of 1:2 showed fastest drug release. The gelatin microspheres of oxybenzone were incorporated in aloe vera gel. Sun exposure method using sodium nitroprusside solution was used for in vitro sunscreen efficacy testing. The formulation C5 containing oxybenzone-bearing gelatin microspheres in aloe vera gel showed best sunscreen efficacy. The formulations were evaluated for skin irritation test in human volunteers, sun protection factor, and minimum erythema dose in albino rats. These studies revealed that the incorporation of sunscreening agent-loaded microspheres into aloe vera gel greatly increased the efficacy of sunscreen formulation more than four times.

Targeting the fibroblast growth factor receptors for the treatment of cancer.

PubMed

Lemieux, Steven M; Hadden, M Kyle

2013-06-01

Receptor tyrosine kinases (RTKs) are transmembrane proteins that play a critical role in stimulating signal transduction cascades to influence cell proliferation, growth, and differentiation and they have also been shown to promote angiogenesis when they are up-regulated or mutated. For this reason, their dysfunction has been implicated in the development of human cancer. Over the past decade, much attention has been devoted to developing inhibitors and antibodies against several classes of RTKs, including vascular endothelial growth factor receptors (VEGFRs), epidermal growth factor receptors (EGFRs), and platelet-derived growth factor receptors (PDGFRs). More recently, interest in the fibroblast growth factor receptor (FGFR) class of RTKs as a drug target for the treatment of cancer has emerged. Signaling through FGFRs is critical for normal cellular function and their dysregulation has been linked to various malignancies such as breast and prostate cancer. This review will focus on the current state of both small molecules and antibodies as FGFR inhibitors to provide insight into their development and future potential as anti-cancer agents.

36 CFR 1238.14 - What are the microfilming requirements for permanent and unscheduled records?

Code of Federal Regulations, 2010 CFR

2010-07-01

... COM. (b) Agencies must use polyester-based silver gelatin type film that conforms to ISO 18901... densitydifference Silver gelatin Conventional Printing or diffuse 0.75 0.15 0.60 Silver gelatin Full reversal...

Properties of gelatin-based films incorporated with chitosan-coated microparticles charged with rutin.

PubMed

Dammak, Ilyes; Bittante, Ana Mônica Quinta Barbosa; Lourenço, Rodrigo Vinicius; do Amaral Sobral, Paulo José

2017-08-01

The aim of this study was development an active film based on gelatin incorporated with antioxidant, rutin carried into microparticles. The complexation between oppositely charged lecithin and chitosan was applied to prepare the chitosan-coated microparticles. The generated microparticles had an average size of 520±4nm and a span of 0.3 were formulated by a rotor-stator homogenize at the homogenization speed 10,000rpm. Composite films were prepared by incorporating chitosan-coated microparticles, at various concentrations (0.05, 0.1, 0.5, or 1% (based on the weight of the gelatin powder)) in the gelatin-based films. For the prepared films, the results showed that obtained physicochemical, water vapor barrier, and mechanical were compared with native gelatin film with a slight decrease for chitosan concentration higher than 0.5%. The microstructure studies done by scanning electron microscopes, revealed different micropores embedded with oil resulting from the incorporation of the microparticles into the gelatin matrix. Moreover, the calorimetric results were comparable to those of gelatin control film with T g value 45°C and increased crystallinity percentage with increasing incorporation of microparticles. This original concept of composite biodegradable films may thus be a good alternative to incorporate liposoluble active compounds to design an active packaging with good properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhancing SERS by Means of Supramolecular Charge Transfer

NASA Technical Reports Server (NTRS)

Wong, Eric; Flood, Amar; Morales, Alfredo

2009-01-01

In a proposed method of sensing small quantities of molecules of interest, surface enhanced Raman scattering (SERS) spectroscopy would be further enhanced by means of intermolecular or supramolecular charge transfer. There is a very large potential market for sensors based on this method for rapid detection of chemical and biological hazards. In SERS, the Raman signals (vibrational spectra) of target molecules become enhanced by factors of the order of 108 when those molecules are in the vicinities of nanostructured substrate surfaces that have been engineered to have plasmon resonances that enhance local electric fields. SERS, as reported in several prior NASA Tech Briefs articles and elsewhere, has remained a research tool and has not yet been developed into a practical technique for sensing of target molecules: this is because the short range (5 to 20 nm) of the field enhancement necessitates engineering of receptor molecules to attract target molecules to the nanostructured substrate surfaces and to enable reliable identification of the target molecules in the presence of interferants. Intermolecular charge-transfer complexes have been used in fluorescence-, photoluminescence-, and electrochemistry-based techniques for sensing target molecules, but, until now, have not been considered for use in SERS-based sensing. The basic idea of the proposed method is to engineer receptor molecules that would be attached to nanostructured SERS substrates and that would interact with the target molecules to form receptor-target supramolecular charge-transfer complexes wherein the charge transfer could be photoexcited.

New targeted therapies in pancreatic cancer.

PubMed

Seicean, Andrada; Petrusel, Livia; Seicean, Radu

2015-05-28

Patients with pancreatic cancer have a poor prognosis with a median survival of 4-6 mo and a 5-year survival of less than 5%. Despite therapy with gemcitabine, patient survival does not exceed 6 mo, likely due to natural resistance to gemcitabine. Therefore, it is hoped that more favorable results can be obtained by using guided immunotherapy against molecular targets. This review summarizes the new leading targeted therapies in pancreatic cancers, focusing on passive and specific immunotherapies. Passive immunotherapy may have a role for treatment in combination with radiochemotherapy, which otherwise destroys the immune system along with tumor cells. It includes mainly therapies targeting against kinases, including epidermal growth factor receptor, Ras/Raf/mitogen-activated protein kinase cascade, human epidermal growth factor receptor 2, insulin growth factor-1 receptor, phosphoinositide 3-kinase/Akt/mTOR and hepatocyte growth factor receptor. Therapies against DNA repair genes, histone deacetylases, microRNA, and pancreatic tumor tissue stromal elements (stromal extracellular matric and stromal pathways) are also discussed. Specific immunotherapies, such as vaccines (whole cell recombinant, peptide, and dendritic cell vaccines), adoptive cell therapy and immunotherapy targeting tumor stem cells, have the role of activating antitumor immune responses. In the future, treatments will likely include personalized medicine, tailored for numerous molecular therapeutic targets of multiple pathogenetic pathways.

TNF-related apoptosis-inducing ligand (TRAIL): A new path to anti-cancer therapies

PubMed Central

Holoch, Peter A.; Griffith, Thomas S.

2009-01-01

Since its discovery in 1995, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor super family, has been under intense focus because of its remarkable ability to induce apoptosis in malignant human cells while leaving normal cells unscathed. Consequently, activation of the apoptotic signaling pathway from the death-inducing TRAIL receptors provides an attractive, biologically-targeted approach to cancer therapy. A great deal of research has focused on deciphering the TRAIL receptor signaling cascade and intracellular regulation of this pathway, as many human tumor cells possess mechanisms of resistance to TRAIL-induced apoptosis. This review focuses on the currently state of knowledge regarding TRAIL signaling and resistance, the preclinical development of therapies targeted at TRAIL receptors and modulators of the pathway, and the results of clinical trials for cancer treatment that have emerged from this base of knowledge. TRAIL-based approaches to cancer therapy vary from systemic administration of recombinant, soluble TRAIL protein with or without the combination of traditional chemotherapy, radiation or novel anticancer agents to agonistic monoclonal antibodies directed against functional TRAIL receptors to TRAIL gene transfer therapy. A better understanding of TRAIL resistance mechanisms may allow for the development of more effective therapies that exploit this cell-mediated pathway to apoptosis. PMID:19836385

Determine Age-structure of Gelatinous Zooplankton Using Optical Coherence Tomography

NASA Astrophysics Data System (ADS)

Bi, H.; Shahrestani, S.; He, Y.

2016-02-01

Gelatinous are delicate and transparent by nature, but are conspicuous in many ecosystems when in bloom. Their proliferations are a bothersome and costly nuisance and influencing important food webs and species interactions. More importantly, gelatinous zooplankton respond to climate change rapidly and understanding their upsurge needs information on their recruitment and population dynamics which in turn require their age-structure. However, ageing gelatinous zooplankton is often restricted by the fact that they shrink under unfavorable conditions. In the present study, we examine the potential of using optical coherence tomography (OCT) to age gelatinous zooplankton. OCT is a non-invasive imaging technique that uses light waves to examine 2D or 3D structure of target objects at a resolution of 3-5 µm. We were able to successfully capture both 3D and 2D images of sea nettle muscle fibers. Preliminary results on ctenophores will be discussed. Overall, this non-destructive sampling allows us to scan and capture images of mesoglea from jellyfish cultured in the lab, using the same individual repeatedly through time, documenting its growth which will provide precise measurements to construct an age key that will be applied to gelatinous zooplankton captured in the field. Coupled with information on abundance, we can start to quantify their recruitment timing and success rate.

Systemic allergic reactions to gelatin included in vaccines as a stabilizer.

PubMed

Sakaguchi, M; Inouye, S

2000-10-01

Most of the children who showed systemic immediate-type reactions, including anaphylactic shock, to measles, mumps, rubella, and varicella vaccines had IgE antibodies to gelatin; thus we suspected that the allergic symptoms are caused by gelatin antigen, which is usually included in these live-virus vaccines as a stabilizer. We hypothesized that the anti-gelatin IgE is elicited by immunization with DTaP (diphtheria-tetanus-acellular pertussis) vaccines, which contained a small amount of gelatin as a spillover protein after purification of pertussis toxin. To test this hypothesis, we conducted a case-control study to determine whether children with anti-gelatin IgE had received gelatin-containing DTaP vaccines, and it was indeed found that all such children in the study had immunization histories that included the gelatin-containing DTaP vaccines. Based on these findings, the vaccine manufacturers had removed gelatin from all the DTaP and live-virus vaccines produced in Japan by 2000.

Transduction of beta3 integrin subunit cDNA confers on human keratinocytes the ability to adhere to gelatin.

PubMed

Kubo, Miyoko; Clark, Richard A F; Katz, Anne B; Taichman, Lorne B; Jin, Zaishun; Zhao, Ying; Moriguchi, Takahiko

2007-04-01

alphavbeta3 is a multiligand integrin receptor that interacts with fibrinogen (FG), fibrin (FB), fibronectin (FN), vitronectin (VN), and denatured collagen. We previously reported that cultured normal human keratinocytes, like in vivo keratinocytes, do not express alphavbeta3 on the cell surface, and do not adhere to and migrate on FG and FB. Furthermore, we reported that human keratinocytes transduced with beta3 integrin subunit cDNA by a retrovirus-mediated transduction method express alphavbeta3 on the cell surface and adhere to FG, FB, FN, and VN significantly compared with beta-galactosidase (beta-gal) cDNA-transduced keratinocytes (control). In this study, we determined whether these beta3 integrin subunit cDNA-transduced keratinocytes or normal human keratinocytes adhere to denatured collagen (gelatin) using a 1 h cell adhesion assay. beta3 cDNA-transduced keratinocytes adhered to gelatin, whereas no significant adhesion was observed with the control cells (beta-gal cDNA-transduced keratinocytes and normal human keratinocytes). The adhesion to gelatin was inhibited by LM609, a monoclonal antibody to alphavbeta3, and RGD peptides but not by normal mouse IgG1 nor RGE peptides. Thus, transduction of beta3 integrin subunit cDNA confers on human keratinocytes the ability to adhere to denatured collagen (gelatin) as well as to FG, FB, VN, and FN. Otherwise, normal human keratinocytes do not adhere to gelatin. These data support the idea that beta3 cDNA-transduced human keratinocytes can be a good material for cultured epithelium to achieve better take rate with acute or chronic wounds, in which FG, FB, and denatured collagen are abundantly present.

Amino acid and proximate composition of fish bone gelatin from different warm-water species: A comparative study

NASA Astrophysics Data System (ADS)

Atma, Y.

2017-03-01

Research on fish bone gelatin has been increased in the last decade. The quality of gelatin depends on its physicochemical properties. Fish bone gelatin from warm-water fishes has a superior amino acid composition than cold-water fishes. The composition of amino acid can determine the strength and stability of gelatin. Thus, it is important to analyze the composition of amino acid as well as proximate composition for potential gelatin material. The warm water fish species used in this study were Grass carp, Pangasius catfish, Catfish, Lizard fish, Tiger-toothed croaker, Pink perch, Red snapper, Brown spotted grouper, and King weakfish. There werre five dominant amino acid in fish bone gelatin including glycine (21.2-36.7%), proline (8.7-11.7%), hydroxyproline (5.3-9.6%), alanine (8.48-12.9%), and glutamic acid (7.23-10.15%). Different warm-water species has some differences in amino acid composition. The proximate composition showed that fishbone gelatin from Pangasius catfish has the highest protein content. The water composition of all fishbone gelatin was well suited to the standard. Meanwhile, based on ash content, only gelatin from gelatin Pangasius catfish met the standard for food industries.

Terminal Performance of Lead Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video

DTIC Science & Technology

2016-04-04

Terminal Performance of Lead-Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video ELIJAH COURTNEY, AMY...quantified using high speed video . The temporary stretch cavities and permanent wound cavities are also characterized. Two factors tend to re- duce the...Performance of Lead-Free Pistol Bullets in Ballistic Gelatin Using Retarding Force Analysis from High Speed Video cavity. In addition, stretching can also

Tissue factor is an angiogenic-specific receptor for factor VII-targeted immunotherapy and photodynamic therapy.

PubMed

Hu, Zhiwei; Cheng, Jijun; Xu, Jie; Ruf, Wolfram; Lockwood, Charles J

2017-02-01

Identification of target molecules specific for angiogenic vascular endothelial cells (VEC), the inner layer of pathological neovasculature, is critical for discovery and development of neovascular-targeting therapy for angiogenesis-dependent human diseases, notably cancer, macular degeneration and endometriosis, in which vascular endothelial growth factor (VEGF) plays a central pathophysiological role. Using VEGF-stimulated vascular endothelial cells (VECs) isolated from microvessels, venous and arterial blood vessels as in vitro angiogenic models and unstimulated VECs as a quiescent VEC model, we examined the expression of tissue factor (TF), a membrane-bound receptor on the angiogenic VEC models compared with quiescent VEC controls. We found that TF is specifically expressed on angiogenic VECs in a time-dependent manner in microvessels, venous and arterial vessels. TF-targeted therapeutic agents, including factor VII (fVII)-IgG1 Fc and fVII-conjugated photosensitizer, can selectively bind angiogenic VECs, but not the quiescent VECs. Moreover, fVII-targeted photodynamic therapy can selectively and completely eradicate angiogenic VECs. We conclude that TF is an angiogenic-specific receptor and the target molecule for fVII-targeted therapeutics. This study supports clinical trials of TF-targeted therapeutics for the treatment of angiogenesis-dependent diseases such as cancer, macular degeneration and endometriosis.

Anaphylaxis to succinylated gelatin in a patient with a meat allergy: galactose-α(1, 3)-galactose (α-gal) as antigenic determinant.

PubMed

Uyttebroek, A; Sabato, V; Bridts, C H; De Clerck, L S; Ebo, D G

2014-11-01

Specific immunoglobulin E (sIgE) antibodies towards the galactose-α(1,3)-galactose (α-gal) moieties may elicit life-threatening and fatal anaphylactic reactions. Patients sensitized to α-gal moieties from mammalian meat may also react towards mammalian gelatins and gelatin-containing drugs such as bovine gelatin-based colloid plasma substitute. The case of a 56 year old woman with a meat allergy who suffered anaphylaxis to succinylated gelatin is reported. Copyright © 2014 Elsevier Inc. All rights reserved.

Improved Cellular Specificity of Plasmonic Nanobubbles versus Nanoparticles in Heterogeneous Cell Systems

PubMed Central

Lukianova-Hleb, Ekaterina Y.; Ren, Xiaoyang; Constantinou, Pamela E.; Danysh, Brian P.; Shenefelt, Derek L.; Carson, Daniel D.; Farach-Carson, Mary C.; Kulchitsky, Vladimir A.; Wu, Xiangwei; Wagner, Daniel S.; Lapotko, Dmitri O.

2012-01-01

The limited specificity of nanoparticle (NP) uptake by target cells associated with a disease is one of the principal challenges of nanomedicine. Using the threshold mechanism of plasmonic nanobubble (PNB) generation and enhanced accumulation and clustering of gold nanoparticles in target cells, we increased the specificity of PNB generation and detection in target versus non-target cells by more than one order of magnitude compared to the specificity of NP uptake by the same cells. This improved cellular specificity of PNBs was demonstrated in six different cell models representing diverse molecular targets such as epidermal growth factor receptor, CD3 receptor, prostate specific membrane antigen and mucin molecule MUC1. Thus PNBs may be a universal method and nano-agent that overcome the problem of non-specific uptake of NPs by non-target cells and improve the specificity of NP-based diagnostics, therapeutics and theranostics at the cell level. PMID:22509318

Improved cellular specificity of plasmonic nanobubbles versus nanoparticles in heterogeneous cell systems.

PubMed

Lukianova-Hleb, Ekaterina Y; Ren, Xiaoyang; Constantinou, Pamela E; Danysh, Brian P; Shenefelt, Derek L; Carson, Daniel D; Farach-Carson, Mary C; Kulchitsky, Vladimir A; Wu, Xiangwei; Wagner, Daniel S; Lapotko, Dmitri O

2012-01-01

The limited specificity of nanoparticle (NP) uptake by target cells associated with a disease is one of the principal challenges of nanomedicine. Using the threshold mechanism of plasmonic nanobubble (PNB) generation and enhanced accumulation and clustering of gold nanoparticles in target cells, we increased the specificity of PNB generation and detection in target versus non-target cells by more than one order of magnitude compared to the specificity of NP uptake by the same cells. This improved cellular specificity of PNBs was demonstrated in six different cell models representing diverse molecular targets such as epidermal growth factor receptor, CD3 receptor, prostate specific membrane antigen and mucin molecule MUC1. Thus PNBs may be a universal method and nano-agent that overcome the problem of non-specific uptake of NPs by non-target cells and improve the specificity of NP-based diagnostics, therapeutics and theranostics at the cell level.

Physico-functional and mechanical properties of chitosan and calcium salts incorporated fish gelatin scaffolds.

PubMed

Jeevithan, E; Jeya Shakila, R; Varatharajakumar, A; Jeyasekaran, G; Sukumar, D

2013-09-01

Four types of fish gelatin scaffolds viz. gelatin (G), gelatin-chitosan (GC), gelatin-calcium acetate (GCA) and gelatin-chitosan-calcium acetate (GCCA) prepared were investigated for their functional properties, biomechanical strength, microstructural changes in relation to biodegradation. GC scaffold was superior with pH 3.15 and viscosity 9.40 cP. Chitosan and calcium acetate improved tensile strength (TS) and Young's modulus (YM), but lowered elongation at break (EAB). GCCA scaffold possessed moderate TS of 19.6 MPa, EAB of 4.76% and YM of 185 MPa. Foaming ability ratio of GC scaffold was high (3.41). GCA and GCCA scaffolds remained for 4 days before complete in vitro biodegradation. GC scaffold had larger cavities (180-300 μm) that were responsible for low swelling ratios and shrinkage factor. GCCA scaffold with moderate swelling rates, mechanical, functional properties and lowered biodegradation rate were found more suitable for biomedical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

A clinical analysis of gelatin allergy and determination of its causal relationship to the previous administration of gelatin-containing acellular pertussis vaccine combined with diphtheria and tetanus toxoids.

PubMed

Nakayama, T; Aizawa, C; Kuno-Sakai, H

1999-02-01

The number of patients with allergic reactions after administration of gelatin-containing live vaccines is increasingly reported in Japan. These allergic reactions appear to be caused by gelatin allergy. It is still unknown how the patients were sensitized to gelatin. To determine the incidence of gelatin allergy and to identify contributing factors to gelatin allergy, we investigated the following clinical aspects: the development of IgE antibodies to gelatin and the relationship of the patients' past history of acellular pertussis vaccine combined with diphtheria and tetanus toxoid (DTaP) to the development of gelatin allergy. We evaluated 366 patient reports, submitted from 1994 to 1997, of adverse reactions after immunization with monovalent measles, mumps, and rubella vaccines containing 0.2% gelatin as stabilizer. On the basis of physician reports, the patients were categorized as to the nature of the adverse reaction. We determined the presence of IgE antibodies to gelatin and obtained past immunization history. The 366 reported patients were categorized as follows: 34 with anaphylaxis, 76 with urticaria, 215 with nonurticarial generalized eruption, and 41 with local reactions only. In 206 patients from whom serum was available, IgE antibodies to gelatin were detected in 25 of 27 (93%) with anaphylaxis, 27 of 48 (56%) with urticaria, and 8 of 90 (9%) with a generalized eruption. None of a group of 41 patients with only local reactions at the injected site and none of a control group of 29 subjects with no adverse reaction had such antibodies. Among 202 patients for whom prior vaccine information was available, all had received DTaP vaccines. Among those for whom the prior DTaP vaccine could be determined to contain gelatin or be free of gelatin, 155 of 158 (98%) subjects had received gelatin-containing DTaP vaccines. This rate is higher than would be expected on the basis of the market share of gelatin-containing (vs gelatin-free) DTaP vaccines (75%). Furthermore, before 1993, when a trivalent measles, mumps, and rubella vaccine (with the same 0.2% gelatin content as the monovalent vaccines) was used and administered before DTaP vaccination, no reports of anaphylaxis to the measles, mumps, and rubella vaccine were received. Most anaphylactic reactions and some urticarial reactions to gelatin-containing measles, mumps, and rubella monovalent vaccines are associated with IgE-mediated gelatin allergy. DTaP immunization histories suggest that the gelatin-containing DTaP vaccine may have a causal relationship to the development of this gelatin allergy.

How glucocorticoid receptors modulate the activity of other transcription factors: a scope beyond tethering.

PubMed

Ratman, Dariusz; Vanden Berghe, Wim; Dejager, Lien; Libert, Claude; Tavernier, Jan; Beck, Ilse M; De Bosscher, Karolien

2013-11-05

The activity of the glucocorticoid receptor (GR), a nuclear receptor transcription factor belonging to subclass 3C of the steroid/thyroid hormone receptor superfamily, is typically triggered by glucocorticoid hormones. Apart from driving gene transcription via binding onto glucocorticoid response elements in regulatory regions of particular target genes, GR can also inhibit gene expression via transrepression, a mechanism largely based on protein:protein interactions. Hereby GR can influence the activity of other transcription factors, without contacting DNA itself. GR is known to inhibit the activity of a growing list of immune-regulating transcription factors. Hence, GCs still rule the clinic for treatments of inflammatory disorders, notwithstanding concomitant deleterious side effects. Although patience is a virtue when it comes to deciphering the many mechanisms GR uses to influence various signaling pathways, the current review is testimony of the fact that groundbreaking mechanistic work has been accumulating over the past years and steadily continues to grow. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Integrin alpha 3 beta 1 participates in the phagocytosis of extracellular matrix molecules by human breast cancer cells.

PubMed

Coopman, P J; Thomas, D M; Gehlsen, K R; Mueller, S C

1996-11-01

The mechanisms and receptors involved in phagocytosis by nonhematopoietic cells are not well understood. The involvement of the alpha 3 beta 1 integrin in phagocytosis of the extracellular matrix by human breast cancer cells was studied. The possible role of this integrin was suggested since alpha 3 and beta 1 but not alpha 2 subunits are concentrated at membrane sites where local degradation of fluorescently labeled gelatin occurs. Strikingly, anti-alpha 3 integrin monoclonal antibodies (mAbs) stimulate the phagocytosis of fluorescently labeled gelatin films, gelatin beads, and Matrigel films in a quantitative phagocytosis assay. Stimulation of the gelatin uptake by the anti-alpha 3 mAb is dose responsive, saturable, and time dependent. Antibodies against other integrin subunits have a lower stimulatory effect (anti-beta 1) or no significant effect (anti-alpha 2, -alpha 5, -alpha 6, and -alpha v) on gelatin phagocytosis. The synthetic HGD-6 human laminin peptide that binds specifically the alpha 3 beta 1 integrin, but not the scrambled HSGD-6 control peptide, also markedly stimulates gelatin uptake in a dose-responsive way. Furthermore, the stimulatory effects of the HGD-6 peptide and the anti-alpha 3 mAb are additive, suggesting that they might promote phagocytosis in different ways. Other laminin (YIGSR, IKVAV) and fibronectin (GRGDS) peptides have no effect on gelatin phagocytosis. Immunofluorescence shows that the alpha 3 and the beta 1, but not the alpha 2 integrin subunit, concentrate into patches on the cell surface after treatment with their respective mAbs. And, both gelatin and the alpha 3 beta 1 but not the alpha 2 beta 1 integrin are cointernalized and routed to acidic vesicles such as lysosomes. In conclusion, we demonstrate that human breast cancer cells locally degrade and phagocytose the extracellular matrix and show for the first time that the alpha 3 beta 1 integrin participates in this phagocytosis. We hypothesize that the anti-alpha 3 antibodies and the laminin peptide HGD-6 activate the alpha 3 beta 1 integrin, which results in a downstream signaling cascade stimulating phagocytosis.

76 FR 40381 - Government-Owned Inventions; Availability for Licensing

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-08

... applications. Breakthrough Immunotherapy for Brain Cancer: Epidermal Growth Factor Receptor Variant III... receptor variant III (EGFRvIII) to use as a promising immunotherapy for aggressive brain cancer... immunotherapy targeting type III variant epidermal growth factor receptor, a glioma-associated antigen. Cancer...

Recrystallization characteristics of high hydrostatic pressure gelatinized normal and waxy corn starch.

PubMed

Li, Wenhao; Tian, Xiaoling; Wang, Peng; Saleh, Ahmed S M; Luo, Qingui; Zheng, Jianmei; Ouyang, Shaohui; Zhang, Guoquan

2016-02-01

High hydrostatic pressure (HHP) can lead to starch gelatinization at room temperature, while the retrogradation mechanism of HHP gelatinized starch is not well known. HHP gelatinized normal and waxy corn starches were stored at room temperature for 192 h in order to investigate the retrogradation characteristics. The scanning electron microscopy (SEM), polarised light microscopy and differential scanning calorimetric (DSC) analysis showed that the pressurization of normal and waxy corn starch suspensions with concentration of 30% (w/v) at 600 MPa for 15 min resulted in a complete gelatinization. In addition, the pressure-gelatinized normal and waxy corn starch gels were stored and subjected to X-ray diffraction (XRD) analysis, resistant starch content determination, swelling power and pasting behavior. The retrograded normal maize and waxy maize starch showed a substantial loss of A-type crystallinity. Both pressure-gelatinized normal and waxy corn starches showed an increase in resistant starch content and relative crystallinity degree with the increase of storage time. In addition, restricted starch swelling power and lower pasting viscosities were observed for these two retrograded starches. The amylose molecule within starch granules has been regarded as the main factor to affect the structural and physicochemical properties during the retrogradation process of HHP-gelatinized starch granules. Copyright © 2015 Elsevier B.V. All rights reserved.

Something old, something new and something borrowed: emerging paradigm of insulin-like growth factor type 1 receptor (IGF-1R) signaling regulation.

PubMed

Girnita, Leonard; Worrall, Claire; Takahashi, Shin-Ichiro; Seregard, Stefan; Girnita, Ada

2014-07-01

The insulin-like growth factor type 1 receptor (IGF-1R) plays a key role in the development and progression of cancer; however, therapeutics targeting it have had disappointing results in the clinic. As a receptor tyrosine kinase (RTK), IGF-1R is traditionally described as an ON/OFF system, with ligand stabilizing the ON state and exclusive kinase-dependent signaling activation. Newly added to the traditional model, ubiquitin-mediated receptor downregulation and degradation was originally described as a response to ligand/receptor interaction and thus inseparable from kinase signaling activation. Yet, the classical model has proven over-simplified and insufficient to explain experimental evidence accumulated over the last decade, including kinase-independent signaling, unbalanced signaling, or dissociation between signaling and receptor downregulation. Based on the recent findings that IGF-1R "borrows" components of G-protein coupled receptor (GPCR) signaling, including β-arrestins and G-protein-related kinases, we discuss the emerging paradigm for the IGF-1R as a functional RTK/GPCR hybrid, which integrates the kinase signaling with the IGF-1R canonical GPCR characteristics. The contradictions to the classical IGF-1R signaling concept as well as the design of anti-IGF-1R therapeutics treatment are considered in the light of this paradigm shift and we advocate recognition of IGF-1R as a valid target for cancer treatment.

[Molecular mechanism of Bupleuri Radix and Scutellariae Radix drug pair for depression based on integrative pharmacology platform of traditional Chinese medicine].

PubMed

Wang, Jian-Ting; Wang, Shang; Liu, Song-Lin; Wang, Yan-Chun; Li, Jia-Geng; Chen, Yu

2018-04-01

Xiaochaihu decoction is a classic prescription of traditional Chinese medicine. Modern research has proved its anti-depression effect. However, its pharmacological mechanism for anti-depression effect is difficult to be unveiled because of the complexity of compound Chinese medicines. Bupleuri Radix and Scutellariae Radix is the core drug pair of Xiaochaihu decoction. In this research, Bupleuri Radix and Scutellariae Radix were analyzed by the integrative pharmacology platform to study its molecular mechanism for anti-depression. One hundred and sixteen active ingredients were predicted, 62 for Bupleuri Radix, mainly including saikosaponins, acids, alcohols, and 54 for Scutellariae Radix, mainly including flavonoids and glycosides. Its anti-depression effect was relevant to 118 core targets, including 22 known disease targets, such as serotonin receptor(HTR2C), activating transcription factor(ATF1, ATF2), δ opioid receptor(OPRD1), μ opioid receptor (OPRM1), κ opioid receptor(OPRK1), inositol monophosphatase(IMPA1), Toll-like receptor 4 (TLR4), histamine H1 receptor(HRH1), neurotrophic factor tyrosine kinase receptor1 (NTRK1), Glycogen synthetase kinase 3β(GSK3β), etc. The antidepressant effect involved positive regulation of transcription from RNA polymerase Ⅱ promoter, transcription factor binding, cytosol, transcriptional regulation of DNA template, enzyme binding, endocrine system, nervous system, neurotrophin signaling pathway, cell growth and death, signal transduction, thyroid hormone signaling pathway and other related biological processes and metabolic pathways. This study provides a scientific evidence for further study of the anti-depression mechanism of this drug pair. Copyright© by the Chinese Pharmaceutical Association.

Biophysically inspired model for functionalized nanocarrier adhesion to cell surface: roles of protein expression and mechanical factors

NASA Astrophysics Data System (ADS)

Ramakrishnan, N.; Tourdot, Richard W.; Eckmann, David M.; Ayyaswamy, Portonovo S.; Muzykantov, Vladimir R.; Radhakrishnan, Ravi

2016-06-01

In order to achieve selective targeting of affinity-ligand coated nanoparticles to the target tissue, it is essential to understand the key mechanisms that govern their capture by the target cell. Next-generation pharmacokinetic (PK) models that systematically account for proteomic and mechanical factors can accelerate the design, validation and translation of targeted nanocarriers (NCs) in the clinic. Towards this objective, we have developed a computational model to delineate the roles played by target protein expression and mechanical factors of the target cell membrane in determining the avidity of functionalized NCs to live cells. Model results show quantitative agreement with in vivo experiments when specific and non-specific contributions to NC binding are taken into account. The specific contributions are accounted for through extensive simulations of multivalent receptor-ligand interactions, membrane mechanics and entropic factors such as membrane undulations and receptor translation. The computed NC avidity is strongly dependent on ligand density, receptor expression, bending mechanics of the target cell membrane, as well as entropic factors associated with the membrane and the receptor motion. Our computational model can predict the in vivo targeting levels of the intracellular adhesion molecule-1 (ICAM1)-coated NCs targeted to the lung, heart, kidney, liver and spleen of mouse, when the contributions due to endothelial capture are accounted for. The effect of other cells (such as monocytes, etc.) do not improve the model predictions at steady state. We demonstrate the predictive utility of our model by predicting partitioning coefficients of functionalized NCs in mice and human tissues and report the statistical accuracy of our model predictions under different scenarios.

Comparative evaluation of zinc oxide eugenol versus gelatin sponge soaked in plasma rich in growth factor in the treatment of dry socket: An initial study

PubMed Central

Pal, U. S.; Singh, Balendra Pratap; Verma, Vikas

2013-01-01

Purpose: The aim of this study was to report a comparison between the zinc oxide eugenol dressing and plasma rich in growth factor (PRGF) with gelatin sponge in the treatment of dry socket. Materials and Methods: This study comprised of 45 patients of dry socket in the span of one year. The patients were randomly divided into three groups on the basis of treatments: Group A (PRGF with gelatin sponge), group B (zinc oxide eugenol group), and group C (irrigation with sterile saline only). The clinical progress was noted at 1st, 2nd, 3rd, 7th, and 15th day after the treatment. Results: Patient's healing was better in group A than in group B but symptomatic pain relief was faster in group B. Group C fared worst in both aspects. Conclusion: We conclude that PRGF with gelatin sponge might be a treatment of choice in the management of dry socket. PMID:23853450

Genomewide Analysis of Aryl Hydrocarbon Receptor Binding Targets Reveals an Extensive Array of Gene Clusters that Control Morphogenetic and Developmental Programs

PubMed Central

Sartor, Maureen A.; Schnekenburger, Michael; Marlowe, Jennifer L.; Reichard, John F.; Wang, Ying; Fan, Yunxia; Ma, Ci; Karyala, Saikumar; Halbleib, Danielle; Liu, Xiangdong; Medvedovic, Mario; Puga, Alvaro

2009-01-01

Background The vertebrate aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that regulates cellular responses to environmental polycyclic and halogenated compounds. The naive receptor is believed to reside in an inactive cytosolic complex that translocates to the nucleus and induces transcription of xenobiotic detoxification genes after activation by ligand. Objectives We conducted an integrative genomewide analysis of AHR gene targets in mouse hepatoma cells and determined whether AHR regulatory functions may take place in the absence of an exogenous ligand. Methods The network of AHR-binding targets in the mouse genome was mapped through a multipronged approach involving chromatin immunoprecipitation/chip and global gene expression signatures. The findings were integrated into a prior functional knowledge base from Gene Ontology, interaction networks, Kyoto Encyclopedia of Genes and Genomes pathways, sequence motif analysis, and literature molecular concepts. Results We found the naive receptor in unstimulated cells bound to an extensive array of gene clusters with functions in regulation of gene expression, differentiation, and pattern specification, connecting multiple morphogenetic and developmental programs. Activation by the ligand displaced the receptor from some of these targets toward sites in the promoters of xenobiotic metabolism genes. Conclusions The vertebrate AHR appears to possess unsuspected regulatory functions that may be potential targets of environmental injury. PMID:19654925

Signal transduction of Helicobacter pylori during interaction with host cell protein receptors of epithelial and immune cells

PubMed Central

Pachathundikandi, Suneesh Kumar; Tegtmeyer, Nicole; Backert, Steffen

2013-01-01

Helicobacter pylori infections can induce pathologies ranging from chronic gastritis, peptic ulceration to gastric cancer. Bacterial isolates harbor numerous well-known adhesins, vacuolating cytotoxin VacA, protease HtrA, urease, peptidoglycan, and type IV secretion systems (T4SS). It appears that H. pylori targets more than 40 known host protein receptors on epithelial or immune cells. A series of T4SS components such as CagL, CagI, CagY, and CagA can bind to the integrin α5β1 receptor. Other targeted membrane-based receptors include the integrins αvβ3, αvβ5, and β2 (CD18), RPTP-α/β, GP130, E-cadherin, fibronectin, laminin, CD46, CD74, ICAM1/LFA1, T-cell receptor, Toll-like receptors, and receptor tyrosine kinases EGFR, ErbB2, ErbB3, and c-Met. In addition, H. pylori is able to activate the intracellular receptors NOD1, NOD2, and NLRP3 with important roles in innate immunity. Here we review the interplay of various bacterial factors with host protein receptors. The contribution of these interactions to signal transduction and pathogenesis is discussed. PMID:24280762

[Targeting of membrane receptor tyrosine kinases: is there resistance in the HER?].

PubMed

Monnier, Lucile; Milano, Gérard; Penault-Llorca, Frédérique; Merlin, Jean-Louis

2004-09-01

Human Epidermal growth factor Receptors (HER) play an important role in cellular proliferation, and differentiation. Their overexpression in tumor tissues is often associated with a poor prognosis. Consequently, HER receptors are interesting therapeutic targets for cancer treatment. Two strategies are proposed. First, monoclonal antibodies can be used to inhibit the binding of one ligand to its receptor. The second approach is based upon the designing of tyrosine kinase inhibitors capable to bind into the phosphorylation site of the receptor. Consequently, both approaches block the signal transduction downstream. Resistance to anti receptor tyrosine kinase therapy can lead to enhanced morbidity associated with high therapeutic cost. Different mechanisms can be implicated. Non specific mechanisms include alterations of the signal transduction pathways (PI3K/AKT), recruitment of alternative receptor tyrosine kinase pathways (IGFR, VEGFR) and proteasome degradation inhibition. Other mechanisms are specific to HER and rely on inhibition of the binding of monoclonal antibodies (sialomucin-MUC4), heterodimerisation of HER, truncated soluble receptors intervention and mutated variants, as demonstrated very recently with EGF receptors, or genetic polymorphism. This paper reviews these different resistance mechanisms that have been identified in preclinical and clinical situations.

3D cell entrapment in crosslinked thiolated gelatin-poly(ethylene glycol) diacrylate hydrogels

PubMed Central

Fu, Yao; Xu, Kedi; Zheng, Xiaoxiang; Giacomin, A. Jeffrey; Mix, Adam W.; Kao, Weiyuan John

2012-01-01

The combined use of natural ECM components and synthetic materials offers an attractive alternative to fabricate hydrogel-based tissue engineering scaffolds to study cell-matrix interactions in three-dimensions (3D). A facile method was developed to modify gelatin with cysteine via a bifunctional PEG linker, thus introducing free thiol groups to gelatin chains. A covalently crosslinked gelatin hydrogel was fabricated using thiolated gelatin and poly(ethylene glycol) diacrylate (PEGdA) via thiol-ene reaction. Unmodified gelatin was physically incorporated in a PEGdA-only matrix for comparison. We sought to understand the effect of crosslinking modality on hydrogel physicochemical properties and the impact on 3D cell entrapment. Compared to physically incorporated gelatin hydrogels, covalently crosslinked gelatin hydrogels displayed higher maximum weight swelling ratio (Qmax), higher water content, significantly lower cumulative gelatin dissolution up to 7 days, and lower gel stiffness. Furthermore, fibroblasts encapsulated within covalently crosslinked gelatin hydrogels showed extensive cytoplasmic spreading and the formation of cellular networks over 28 days. In contrast, fibroblasts encapsulated in the physically incorporated gelatin hydrogels remained spheroidal. Hence, crosslinking ECM protein with synthetic matrix creates a stable scaffold with tunable mechanical properties and with long-term cell anchorage points, thus supporting cell attachment and growth in the 3D environment. PMID:21955690

Gelatin controversies in food, pharmaceuticals, and personal care products: Authentication methods, current status, and future challenges.

PubMed

Ali, Eaqub; Sultana, Sharmin; Hamid, Sharifah Bee Abd; Hossain, Motalib; Yehya, Wageeh A; Kader, Abdul; Bhargava, Suresh K

2018-06-13

Gelatin is a highly purified animal protein of pig, cow, and fish origins and is extensively used in food, pharmaceuticals, and personal care products. However, the acceptability of gelatin products greatly depends on the animal sources of the gelatin. Porcine and bovine gelatins have attractive features but limited acceptance because of religious prohibitions and potential zoonotic threats, whereas fish gelatin is welcomed in all religions and cultures. Thus, source authentication is a must for gelatin products but it is greatly challenging due to the breakdown of both protein and DNA biomarkers in processed gelatins. Therefore, several methods have been proposed for gelatin identification, but a comprehensive and systematic document that includes all of the techniques does not exist. This up-to-date review addresses this research gap and presents, in an accessible format, the major gelatin source authentication techniques, which are primarily nucleic acid and protein based. Instead of presenting these methods in paragraph form which needs much attention in reading, the major methods are schematically depicted, and their comparative features are tabulated. Future technologies are forecasted, and challenges are outlined. Overall, this review paper has the merit to serve as a reference guide for the production and application of gelatin in academia and industry and will act as a platform for the development of improved methods for gelatin authentication.

Modification of gelatin-DNA interaction for optimised DNA extraction from gelatin and gelatin capsule.

PubMed

Mohamad, Nurhidayatul Asma; Mustafa, Shuhaimi; El Sheikha, Aly Farag; Khairil Mokhtar, Nur Fadhilah; Ismail, Amin; Ali, Md Eaqub

2016-05-01

Poor quality and quantity of DNA extracted from gelatin and gelatin capsules often causes failure in the determination of animal species using PCR. Gelatin, which is mainly derived from porcine and bovine, has been a matter of concern among customers in order to fulfill religious obligation and safety precaution against several transmissible infectious diseases associated with bovine species. Thus, optimised DNA extraction from gelatin is very important for successful real-time PCR detection of gelatin species. In this work, the DNA extraction method was optimised in terms of lysis incubation period and inclusion of pre-treatment pH modification of samples. The yield of DNA extracted from porcine gelatin was significantly increased when the pH of the samples was adjusted to pH 8.5 prior to DNA precipitation with isopropanol. The optimal pH for DNA precipitation from bovine gelatin solution was then determined at the original pH range of solution: pH 7.6 to 8. A DNA fragment of approximately 300 base pairs was available for PCR amplification. DNA extracted from gelatin and commercially available capsules has been successfully utilised for species detection using real-time PCR assay. However, significant adulterations of porcine and bovine in pure gelatin and capsules have been detected, which require further analytical techniques for validation. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Epidermal growth factor receptor and EGFRvIII in glioblastoma: signaling pathways and targeted therapies. | Office of Cancer Genomics

Cancer.gov

Amplification of epidermal growth factor receptor (EGFR) and its active mutant EGFRvIII occurs frequently in glioblastoma (GBM). While EGFR and EGFRvIII play critical roles in pathogenesis, targeted therapy with EGFR-tyrosine kinase inhibitors (TKIs) or antibodies has only shown limited efficacy in patients. Here we discuss signaling pathways mediated by EGFR/EGFRvIII, current therapeutics, and novel strategies to target EGFR/EGFRvIII-amplified GBM.

Fish gelatin.

PubMed

Boran, Gokhan; Regenstein, Joe M

2010-01-01

Gelatin is a multifunctional ingredient used in foods, pharmaceuticals, cosmetics, and photographic films as a gelling agent, stabilizer, thickener, emulsifier, and film former. As a thermoreversible hydrocolloid with a narrower gap between its melting and gelling temperatures, both of which are below human body temperature, gelatin provides unique advantages over carbohydrate-based gelling agents. Gelatin is mostly produced from pig skin, and cattle hides and bones. Some alternative raw materials have recently gained attention from both researchers and the industry not just because they overcome religious concerns shared by Jews and Muslims but also because they provide, in some cases, technological advantages over mammalian gelatins. Fish skins from a number of fish species are among the other sources that have been comprehensively studied as sources for gelatin production. Fish skins have a significant potential for the production of high-quality gelatin with different melting and gelling temperatures over a much wider range than mammalian gelatins, yet still have a sufficiently high gel strength and viscosity. Gelatin quality is industrially determined by gel strength, viscosity, melting or gelling temperatures, the water content, and microbiological safety. For gelatin manufacturers, yield from a particular raw material is also important. Recent experimental studies have shown that these quality parameters vary greatly depending on the biochemical characteristics of the raw materials, the manufacturing processes applied, and the experimental settings used for quality control tests. In this review, the gelatin quality achieved from different fish species is reviewed along with the experimental procedures used to determine gelatin quality. In addition, the chemical structure of collagen and gelatin, the collagen-gelatin conversion, the gelation process, and the gelatin market are discussed. Copyright © 2010 Elsevier Inc. All rights reserved.

[Perspectives of the stomach cancer treatment: the introduction of molecular targeted therapy and the hope for cure].

PubMed

Cheung, Dae Young; Kim, Jae Kwang

2013-03-25

The overall survival of patients with gastric cancer has increased markedly in Korea, even higher than those of developed nations in Western world. It is due to the virtue of Korean National Cancer Screening Program and nowadays more than half of patients are diagnosed at the early stage of gastric cancer. However, for patients with unresectable gastric cancer, the outcomes of traditional cytotoxic chemotherapy regimens stay at a median survival of 9-11 months. The knowledge of cancer biology and the data from gene expression profiling has explosively expanded. Alternations in the expression of receptor tyrosine kinases pathways including Human epidermal growth factor receptor 2 (HER2), epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF), phosphatydyl inositol 3 kinase/mammalian target of rapamycin (PI3K/mTOR), hepatocyte growth factor receptor (HGFR/MET), and fibroblast growth factor receptor (FGFR) were proved to be critical in cancer cell survival and biological agents targeting those altered receptor tyrosine kinases, their ligands and downstream effector molecules are developed for anti-cancer purpose. Until now, only trastuzumab succeeded to significantly increase overall survival of patients with HER2 overexpressing gastric cancer. Other agents including bevacizumab, gefitinib, erlotinib, and lapatinib failed to achieve the efficacy in survival gain over standard chemotherapy. Insights about the variations between regions, races, and individuals call for the effort to find reliable predictive biomarkers for drug efficacy and to design finely stratified clinical trials. Compared to current treatment paradigms, it is hoped that molecularly targeted treatment along with conventional cytotoxic chemotherapy will lead to significant gains in survival.

Treatment challenges for community oncologists treating postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer

PubMed Central

Gradishar, William J

2016-01-01

Community-based oncologists are faced with challenges and opportunities when delivering quality patient care, including high patient volumes and diminished resources; however, there may be the potential to deliver increased patient education and subsequently improve outcomes. This review discusses the treatment of postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2- negative advanced breast cancer in order to illustrate considerations in the provision of pertinent quality education in the treatment of these patients and the management of therapy-related adverse events. An overview of endocrine-resistant breast cancer and subsequent treatment challenges is also provided. Approved treatment options for endocrine-resistant breast cancer include hormonal therapies and mammalian target of rapamycin inhibitors. Compounds under clinical investigation are also discussed. PMID:27468248

Insight into pattern of codon biasness and nucleotide base usage in serotonin receptor gene family from different mammalian species.

PubMed

Dass, J Febin Prabhu; Sudandiradoss, C

2012-07-15

5-HT (5-Hydroxy-tryptamine) or serotonin receptors are found both in central and peripheral nervous system as well as in non-neuronal tissues. In the animal and human nervous system, serotonin produces various functional effects through a variety of membrane bound receptors. In this study, we focus on 5-HT receptor family from different mammals and examined the factors that account for codon and nucleotide usage variation. A total of 110 homologous coding sequences from 11 different mammalian species were analyzed using relative synonymous codon usage (RSCU), correspondence analysis (COA) and hierarchical cluster analysis together with nucleotide base usage frequency of chemically similar amino acid codons. The mean effective number of codon (ENc) value of 37.06 for 5-HT(6) shows very high codon bias within the family and may be due to high selective translational efficiency. The COA and Spearman's rank correlation reveals that the nucleotide compositional mutation bias as the major factors influencing the codon usage in serotonin receptor genes. The hierarchical cluster analysis suggests that gene function is another dominant factor that affects the codon usage bias, while species is a minor factor. Nucleotide base usage was reported using Goldman, Engelman, Stietz (GES) scale reveals the presence of high uracil (>45%) content at functionally important hydrophobic regions. Our in silico approach will certainly help for further investigations on critical inference on evolution, structure, function and gene expression aspects of 5-HT receptors family which are potential antipsychotic drug targets. Copyright © 2012 Elsevier B.V. All rights reserved.

Effect of Graphite Concentration on Shear-Wave Speed in Gelatin-Based Tissue-Mimicking Phantoms

PubMed Central

Anderson, Pamela G.; Rouze, Ned C.; Palmeri, Mark L.

2011-01-01

Elasticity-based imaging modalities are becoming popular diagnostic tools in clinical practice. Gelatin-based, tissue mimicking phantoms that contain graphite as the acoustic scattering material are commonly used in testing and validating elasticity-imaging methods to quantify tissue stiffness. The gelatin bloom strength and concentration are used to control phantom stiffness. While it is known that graphite concentration can be modulated to control acoustic attenuation, the impact of graphite concentrationon phantom elasticity has not been characterized in these gelatin phantoms. This work investigates the impact of graphite concentration on phantom shear stiffness as characterized by shear-wave speed measurements using impulsive acoustic-radiation-force excitations. Phantom shear-wave speed increased by 0.83 (m/s)/(dB/(cm MHz)) when increasing the attenuation coefficient slope of the phantom material through increasing graphite concentration. Therefore, gelatin-phantom stiffness can be affected by the conventional ways that attenuation is modulated through graphite concentration in these phantoms. PMID:21710828

Nanoparticles for targeted delivery of therapeutics and small interfering RNAs in hepatocellular carcinoma

PubMed Central

Varshosaz, Jaleh; Farzan, Maryam

2015-01-01

Hepatocellular carcinoma (HCC) is the 5th most common malignancy which is responsible for more than half million annual mortalities; also, it is the third leading cause of cancer related death. Unfavorable systemic side-effects of chemotherapeutic agents and susceptibility to the degradation of small interfering RNAs (siRNAs), which can knock down a specific gene involved in the disease, have hampered their clinical application. So, it could be beneficial to develop an efficient carrier for the stabilization and specific delivery of drugs and siRNA to cells. Targeted nanoparticles have gained considerable attention as an efficient drug and gene delivery system, which is due to their capability in achieving the highest accumulation of cytotoxic agents in tumor tissue, modifiable drug pharmacokinetic- and bio-distribution, improved effectiveness of treatment, and limited side-effects. Recent studies have shed more light on the advantages of novel drug loaded carrier systems vs free drugs. Most of the animal studies have reported improvement in treatment efficacy and survival rate using novel carrier systems. Targeted delivery may be achieved passively or actively. In passive targeting, no ligand as homing device is used, while targeting is achieved by incorporating the therapeutic agent into a macromolecule or nanoparticle that passively reaches the target organ. However, in active targeting, the therapeutic agent or carrier system is conjugated to a tissue or cell-specific receptor which is over-expressed in a special malignancy using a ligand called a homing device. This review covers a broad spectrum of targeted nanoparticles as therapeutic and non-viral siRNA delivery systems, which are developed for enhanced cellular uptake and targeted gene silencing in vitro and in vivo and their characteristics and opportunities for the clinical applications of drugs and therapeutic siRNA are discussed in this article. Asialoglycoprotein receptors, low-density lipoprotein, ganglioside GM1 cell surface ligand, epidermal growth factor receptor receptors, monoclonal antibodies, retinoic acid receptors, integrin receptors targeted by Arg-Gly-Asp peptide, folate, and transferrin receptors are the most widely studied cell surface receptors which are used for the site specific delivery of drugs and siRNA-based therapeutics in HCC and discussed in detail in this article. PMID:26576089

Preparation and Imaging Investigation of Dual-targeted C3F8-filled PLGA Nanobubbles as a Novel Ultrasound Contrast Agent for Breast Cancer.

PubMed

Du, Jing; Li, Xiao-Yu; Hu, He; Xu, Li; Yang, Shi-Ping; Li, Feng-Hua

2018-03-01

Molecularly-targeted contrast enhanced ultrasound (US) imaging is a promising imaging strategy with large potential for improving diagnostic accuracy of conventional US imaging in breast cancer detection. Therefore, we constructed a novel dual-targeted nanosized US contrast agent (UCA) directed at both vascular endothelial growth factor receptor 2 (VEGFR2) and human epidermal growth factor receptor 2 (HER2) based on perfluoropropane (C 3 F 8 )-filled poly(lactic-co-glycolic acid) (PLGA) (NBs) for breast cancer detection. In vitro, single- or dual-targeted PLGA NBs showed high target specificities and better effects of target enhancement in VEGFR2 or HER2-positive cells. In vivo, US imaging signal in the murine breast cancer model was significantly higher (P < 0.01) for dual-targeted NBs than single-targeted and non-targeted NBs. Small animal fluorescence imaging further confirmed the special affinity of the dual-targeted nanosized contrast agent to both VEGFR2 and HER2. Immunofluorescence and immunohistochemistry staining confirmed the expressions of VEGFR2 and HER2 on tumor neovasculature and tumor cells of breast cancer. In conclusions, the feasibility of using dual-targeted PLGA NBs to enhance ultrasonic images is demonstrated in vitro and in vivo. This may be a promising approach to target biomarkers of breast cancer for two site-specific US molecular imaging.

Biodistribution and pharmacokinetic analysis of long-circulating thiolated gelatin nanoparticles following systemic administration in breast cancer-bearing mice.

PubMed

Kommareddy, Sushma; Amiji, Mansoor

2007-02-01

The objective of the present study was to modify thiolated gelatin nanoparticles with poly(ethylene glycol) (PEG) chains and examine their long circulating and tumor-targeting properties in vivo in an orthotopic a human breast adenocarcinoma xenograft model. The crosslinked nanoparticle systems were characterized to have a size of 150-250 nm with rapid payload release properties in a highly reducing environment. Upon PEG modification, the nanoparticle size increased to 300-350 nm in diameter. The presence of PEG chains on the surface was confirmed by characterization with electron spectroscopy for chemical analysis. The in vivo long-circulating potential, biodistribution and passive tumor targeting of the controls, and PEG-modified thiolated gelatin nanoparticles were evaluated by injecting indium-111 (111In)-labeled nanoparticles into breast tumor (MDA-MB-435)-bearing nude mice. Upon modification with PEG, the nanoparticles were found to have longer circulation times, with the plasma and tumor half-lives of 15.3 and 37.8 h, respectively. The results also showed preferential localization of thiolated nanoparticles in the tumor mass. The resulting nanoparticulate systems with long circulation properties could be used to target encapsulated drugs and genes to tumors passively by utilizing the enhanced permeability and retention effect of the tumor vasculature. Copyright (c) 2006 Wiley-Liss, Inc.

New perspectives on targeted therapy in ovarian cancer

PubMed Central

Coward, Jermaine IG; Middleton, Kathryn; Murphy, Felicity

2015-01-01

Epithelial ovarian cancer remains the most lethal gynecologic malignancy. During the last 15 years, there has been only marginal improvement in 5 year overall survival. These daunting statistics are compounded by the fact that despite all subtypes exhibiting striking heterogeneity, their systemic management remains identical. Although changes to the scheduling and administration of chemotherapy have improved outcomes to a degree, a therapeutic ceiling is being reached with this approach, resulting in a number of trials investigating the efficacy of targeted therapies alongside standard treatment algorithms. Furthermore, there is an urge to develop subtype-specific studies in an attempt to improve outcomes, which currently remain poor. This review summarizes the key studies with antiangiogenic agents, poly(adenosine diphosphate [ADP]-ribose) inhibitors, and epidermal growth factor receptor/human epidermal growth factor receptor family targeting, in addition to folate receptor antagonists and insulin growth factor receptor inhibitors. The efficacy of treatment paradigms used in non-ovarian malignancies for type I tumors is also highlighted, in addition to recent advances in appropriate patient stratification for targeted therapies in epithelial ovarian cancer. PMID:25678824

Barium-cross-linked alginate-gelatine microcapsule as a potential platform for stem cell production and modular tissue formation.

PubMed

Alizadeh Sardroud, Hamed; Nemati, Sorour; Baradar Khoshfetrat, Ali; Nabavinia, Mahbobeh; Beygi Khosrowshahi, Younes

2017-08-01

Influence of gelatine concentration and cross-linker ions of Ca 2+ and Ba 2+ was evaluated on characteristics of alginate hydrogels and proliferation behaviours of model adherent and suspendable stem cells of fibroblast and U937 embedded in alginate microcapsules. Increasing gelatine concentration to 2.5% increased extent of swelling to 15% and 25% for barium- and calcium-cross-linked hydrogels, respectively. Mechanical properties also decreased with increasing swelling of hydrogels. Both by increasing gelatine concentration and using barium ions increased considerably the proliferation of encapsulated model stem cells. Barium-cross-linked alginate-gelatine microcapsule tested for bone building block showed a 13.5 ± 1.5-fold expansion for osteoblast cells after 21 days with deposition of bone matrix. The haematopoietic stem cells cultured in the microcapsule after 7 days also showed up to 2-fold increase without adding any growth factor. The study demonstrates that barium-cross-linked alginate-gelatine microcapsule has potential for use as a simple and efficient 3D platform for stem cell production and modular tissue formation.

Non-toxic agarose/gelatin-based microencapsulation system containing gallic acid for antifungal application.

PubMed

Lam, P-L; Gambari, R; Kok, S H-L; Lam, K-H; Tang, J C-O; Bian, Z-X; Lee, K K-H; Chui, C-H

2015-02-01

Aspergillus niger (A. niger) is a common species of Aspergillus molds. Cutaneous aspergillosis usually occurs in skin sites near intravenous injection and approximately 6% of cutaneous aspergillosis cases which do not involve burn or HIV-infected patients are caused by A. niger. Biomaterials and biopharmaceuticals produced from microparticle-based drug delivery systems have received much attention as microencapsulated drugs offer an improvement in therapeutic efficacy due to better human absorption. The frequently used crosslinker, glutaraldehyde, in gelatin-based microencapsulation systems is considered harmful to human beings. In order to tackle the potential risks, agarose has become an alternative polymer to be used with gelatin as wall matrix materials of microcapsules. In the present study, we report the eco-friendly use of an agarose/gelatin-based microencapsulation system to enhance the antifungal activity of gallic acid and reduce its potential cytotoxic effects towards human skin keratinocytes. We used optimal parameter combinations, such as an agarose/gelatin ratio of 1:1, a polymer/oil ratio of 1:60, a surfactant volume of 1% w/w and a stirring speed of 900 rpm. The minimum inhibitory concentration of microencapsulated gallic acid (62.5 µg/ml) was significantly improved when compared with that of the original drug (>750 µg/ml). The anti-A. niger activity of gallic acid -containing microcapsules was much stronger than that of the original drug. Following 48 h of treatment, skin cell survival was approximately 90% with agarose/gelatin microcapsules containing gallic acid, whereas cell viability was only 25-35% with free gallic acid. Our results demonstrate that agarose/gelatin-based microcapsules containing gallic acid may prove to be helpful in the treatment of A. niger-induced skin infections near intravenous injection sites.

Mechanism-Based Tumor-Targeting Drug Delivery System. Validation of Efficient Vitamin Receptor-Mediated Endocytosis and Drug Release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, S.; Wong, S.; Zhao, X.

An efficient mechanism-based tumor-targeting drug delivery system, based on tumor-specific vitamin-receptor mediated endocytosis, has been developed. The tumor-targeting drug delivery system is a conjugate of a tumor-targeting molecule (biotin: vitamin H or vitamin B-7), a mechanism-based self-immolative linker and a second-generation taxoid (SB-T-1214) as the cytotoxic agent. This conjugate (1) is designed to be (i) specific to the vitamin receptors overexpressed on tumor cell surface and (ii) internalized efficiently through receptor-mediated endocytosis, followed by smooth drug release via glutathione-triggered self-immolation of the linker. In order to monitor and validate the sequence of events hypothesized, i.e., receptor-mediated endocytosis of the conjugate,more » drug release, and drug-binding to the target protein (microtubules), three fluorescent/fluorogenic molecular probes (2, 3, and 4) were designed and synthesized. The actual occurrence of these processes was unambiguously confirmed by means of confocal fluorescence microscopy (CFM) and flow cytometry using L1210FR leukemia cells, overexpressing biotin receptors. The molecular probe 4, bearing the taxoid linked to fluorescein, was also used to examine the cell specificity (i.e., efficacy of receptor-based cell targeting) for three cell lines, L1210FR (biotin receptors overexpressed), L1210 (biotin receptors not overexpressed), and WI38 (normal human lung fibroblast, biotin receptor negative). As anticipated, the molecular probe 4 exhibited high specificity only to L1210FR. To confirm the direct correlation between the cell-specific drug delivery and anticancer activity of the probe 4, its cytotoxicity against these three cell lines was also examined. The results clearly showed a good correlation between the two methods. In the same manner, excellent cell-specific cytotoxicity of the conjugate 1 (without fluorescein attachment to the taxoid) against the same three cell lines was confirmed. This mechanism-based tumor-targeting drug delivery system will find a range of applications.« less

Dietary supplementation with very long-chain n-3 fatty acids in man decreases expression of the interleukin-2 receptor (CD25) on mitogen-stimulated lymphocytes from patients with inflammatory skin diseases.

PubMed

Søyland, E; Lea, T; Sandstad, B; Drevon, A

1994-04-01

T-cell activation and cytokine production play an important role in several chronic inflammatory diseases. Because n-3 fatty acids exert beneficial effects on the clinical state of some of these diseases, we examined the effect of dietary supplementation of n-3 fatty acids on T-cell proliferation, expression of CD25 (interleukin-2 receptor alpha-chain), secretion of interleukin-2, interleukin-6 and tumour necrosis factor from T-cells from patients with psoriasis and atopic dermatitis. During 4 months, 21 patients supplied 6 g of highly concentrated ethyl esters of EPA and DHA in gelatin capsules daily to their diet. In the control group 20 patients supplied 6 g per day of corn oil in gelatin capsules to their diet. Eicosapentaenoic acid (20:5, n-3) of serum phospholipids increased from 14 (min 4-max 42) to 81 (min 59-max 144) mg l-1 (P < 0.01) in patients with atopic dermatitis receiving n-3 fatty acids, and from 25 (min 7-max 66) to 74 (min 46-max 142) mg l-1 (P < 0.01) in patients with psoriasis, whereas docosahexaenoic acid (22:6, n-3) increased from 65 (min 46-max 120) to 92 (min 54-max 121) mg l-1 (P < 0.05) and from 81 (min 38-max 122) to 92 (min 63-max 169) mg l-1 (NS) in atopic and psoriatic patients, respectively. The changes in the serum phospholipid fatty acid profile in the groups receiving n-3 fatty acids, correlate to the dietary intake of corresponding fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Solution-processed Al-chelated gelatin for highly transparent non-volatile memory applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, Yu-Chi; Wang, Yeong-Her, E-mail: yhw@ee.ncku.edu.tw

2015-03-23

Using the biomaterial of Al-chelated gelatin (ACG) prepared by sol-gel method in the ITO/ACG/ITO structure, a highly transparent resistive random access memory (RRAM) was obtained. The transmittance of the fabricated device is approximately 83% at 550 nm while that of Al/gelatin/ITO is opaque. As to the ITO/gelatin/ITO RRAM, no resistive switching behavior can be seen. The ITO/ACG/ITO RRAM shows high ON/OFF current ratio (>10{sup 5}), low operation voltage, good uniformity, and retention characteristics at room temperature and 85 °C. The mechanism of the ACG-based memory devices is presented. The enhancement of these electrical properties can be attributed to the chelate effect ofmore » Al ions with gelatin. Results show that transparent ACG-based memory devices possess the potential for next-generation resistive memories and bio-electronic applications.« less

Vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitors: development and validation of predictive 3-D QSAR models through extensive ligand- and structure-based approaches

NASA Astrophysics Data System (ADS)

Ragno, Rino; Ballante, Flavio; Pirolli, Adele; Wickersham, Richard B.; Patsilinakos, Alexandros; Hesse, Stéphanie; Perspicace, Enrico; Kirsch, Gilbert

2015-08-01

Vascular endothelial growth factor receptor-2, (VEGFR-2), is a key element in angiogenesis, the process by which new blood vessels are formed, and is thus an important pharmaceutical target. Here, 3-D quantitative structure-activity relationship (3-D QSAR) were used to build a quantitative screening and pharmacophore model of the VEGFR-2 receptors for design of inhibitors with improved activities. Most of available experimental data information has been used as training set to derive optimized and fully cross-validated eight mono-probe and a multi-probe quantitative models. Notable is the use of 262 molecules, aligned following both structure-based and ligand-based protocols, as external test set confirming the 3-D QSAR models' predictive capability and their usefulness in design new VEGFR-2 inhibitors. From a survey on literature, this is the first generation of a wide-ranging computational medicinal chemistry application on VEGFR2 inhibitors.

Gelatin Nano-coating for Inhibiting Surface Crystallization of Amorphous Drugs.

PubMed

Teerakapibal, Rattavut; Gui, Yue; Yu, Lian

2018-01-05

Inhibit the fast surface crystallization of amorphous drugs with gelatin nano-coatings. The free surface of amorphous films of indomethacin or nifedipine was coated by a gelatin solution (type A or B) and dried. The coating's effect on surface crystallization was evaluated. Coating thickness was estimated from mass change after coating. For indomethacin (weak acid, pK a  = 4.5), a gelatin coating of either type deposited at pH 5 and 10 inhibited its fast surface crystal growth. The coating thickness was 20 ± 10 nm. A gelatin coating deposited at pH 3, however, provided no protective effect. These results suggest that an effective gelatin coating does not require that the drug and the polymer have opposite charges. The ineffective pH 3 coating might reflect the poor wetting of indomethacin's neutral, hydrophobic surface by the coating solution. For nifedipine (weak base, pK a  = 2.6), a gelatin coating of either type deposited at pH 5 inhibited its fast surface crystal growth. Gelatin nano-coatings can be conveniently applied to amorphous drugs from solution to inhibit fast surface crystallization. Unlike strong polyelectrolyte coatings, a protective gelatin coating does not require strict pairing of opposite charges. This could make gelatin coating a versatile, pharmaceutically acceptable coating for stabilizing amorphous drugs.

Development and Characterization of Biodegradable Composite Films Based on Gelatin Derived from Beef, Pork and Fish Sources

PubMed Central

Nur Hanani, Zainal A.; Beatty, Eddie; Roos, Yrjo H.; Morris, Mick A.; Kerry, Joseph P.

2012-01-01

The objectives of this study were to develop composite films using various gelatin sources with corn oil (CO) incorporation (55.18%) and to investigate the mechanical and physical properties of these films as potential packaging films. There were increases (p < 0.05) in the tensile strength (TS) and puncture strength (PS) of films when the concentration of gelatin increased. The mechanical properties of these films were also improved when compared with films produced without CO. Conversely, the water barrier properties of composite films decreased (p < 0.05) when the concentration of gelatin in composite films increased. Comparing with pure gelatin films, water and oxygen barrier properties of gelatin films decreased when manufactured with the inclusion of CO. PMID:28239092

New dichromated gelatin technologies for diffraction optical element fabrication

NASA Astrophysics Data System (ADS)

Vigovsky, Yury N.; Malov, Alexander N.; Malov, Sergey N.; Feshchenko, Valeriy S.; Konop, Sergey P.

1998-01-01

The hologram recording mechanism in the dichromated gelatin layers are discussed. A new technologies are described for red rainbow hologram recording in the photographic emulsion and selfdeveloped dichromated gelatin--glycerol layers. A new method is suggested and experimentally approbated for relief plastic replica of the rainbow hologram fabrication based on the tanning developed or bleached photographic emulsion. This method is modification of the old photographic `bromoil' process. Some aspects of the noncoherent hologram coping on the dichromated gelatin films are discussed too.

Magnetic Resonance Based Electrical Property Tomography (MR-EPT) for Prostate Cancer Grade Imaging

DTIC Science & Technology

2015-07-01

weight of dry porcine gelatin , and approximately 1% by weight of NaCl to adjust conductivity to the desired level. A saline solution with a conductivity...conductivity changes). Figure 2 displays a curvilinear gelatin phantom conducted along with the MR magnitude image 7 Surface Integral Reconstruction... gelatin slab which is immersed in a saline solution. The gelatin slab has a conductivity of of 1.8 S/m and Copper sulfate (CuSO4) was added to it, to

Dextran and gelatin based photocrosslinkable tissue adhesive.

PubMed

Wang, Tao; Nie, Jun; Yang, Dongzhi

2012-11-06

A two-component tissue adhesive based on biocompatible and bio-degradable polymers (oxidized urethane dextran (Dex-U-AD) and gelatin) was prepared and photocrosslinked under the ultraviolet (UV) irradiation. The adhesive could adhere to surface of gelatin, which simulated the human tissue steadily. The structures of above Dex-U-AD were characterized by FTIR, (1)H NMR spectroscopy and XRD. The adhesion property of result products was evaluated by lap-shear test. The maximum adhesion strength could reach to 4.16±0.72 MPa which was significantly higher than that of fibrin glue. The photopolymerization process of Dex-U-AD/gelatin was monitored by real time infrared spectroscopy (RTIR). It took less than 5 min to complete the curing process. The cytotoxicity of Dex-U-AD/gelatin also was evaluated which indicated that Dex-U-AD/gelatin gels were nontoxic to L929 cell. The relationship between all the above-mentioned properties and degree of oxidization of Dex-U-AD was assessed. The obtained products have the potential to serve as tissue adhesive in the future. Copyright © 2012 Elsevier Ltd. All rights reserved.

Evaluation of a novel virtual screening strategy using receptor decoy binding sites.

PubMed

Patel, Hershna; Kukol, Andreas

2016-08-23

Virtual screening is used in biomedical research to predict the binding affinity of a large set of small organic molecules to protein receptor targets. This report shows the development and evaluation of a novel yet straightforward attempt to improve this ranking in receptor-based molecular docking using a receptor-decoy strategy. This strategy includes defining a decoy binding site on the receptor and adjusting the ranking of the true binding-site virtual screen based on the decoy-site screen. The results show that by docking against a receptor-decoy site with Autodock Vina, improved Receiver Operator Characteristic Enrichment (ROCE) was achieved for 5 out of fifteen receptor targets investigated, when up to 15 % of a decoy site rank list was considered. No improved enrichment was seen for 7 targets, while for 3 targets the ROCE was reduced. The extent to which this strategy can effectively improve ligand prediction is dependent on the target receptor investigated.

Engineering of cell-laden gelatin-based microgels for cell delivery and immobilization in regenerative therapies.

PubMed

Blocki, Anna; Löper, Farina; Chirico, Nino; Neffe, Axel T; Jung, Friedrich; Stamm, Christof; Lendlein, Andreas

2017-01-01

Cell-based therapies often face the challenge of low cell retention and viability upon transplantation. Hence, biomaterials, which can immobilize transplanted cells, while at the same time support cell viability, are essential for successful clinical application. Noteworthy, biomaterials in the micrometer range such as microcapsules or microspheres have the advantage of a minimally invasive introduction into tissue.Hence, we established an approach to generate gelatin-based cell carriers in the form of microspherical hydrogels. Fibroblasts were microencapsulated in glycidylmethacrylate (GMA)-functionalized gelatin by photopolymerization. While the degree of GMA-functionalization was kept constant, the hydrogel cross-linking density was adjusted by varying the time of irradiation or the average gelatin-chain length.Stable microspheres were synthesized from 10 wt% GMA-gelatin solutions for all irradiation periods tested (0.5 -2 min). Evaluation of cell viability revealed that microgels with the same weight content of biopolymer but with decreased cross-linking densities and thus decreased storage and E modulus, resulted in best cell support. Noteworthy, encapsulated cells partially migrated out of the microspheres and attached to the spherical surface.10 wt% GMA-gelatin-based hydrogels with E moduli comparable to the native cellular niche proved to be a promising biomaterial suitable for the production of cell-laden microspheres and shall be evaluated further for biomedical application.

Suppression of transient receptor potential melastatin 4 expression promotes conversion of endothelial cells into fibroblasts via transforming growth factor/activin receptor-like kinase 5 pathway.

PubMed

Echeverría, Cesar; Montorfano, Ignacio; Cabello-Verrugio, Claudio; Armisén, Ricardo; Varela, Diego; Simon, Felipe

2015-05-01

To study whether transient receptor potential melastatin 4 (TRPM4) participates in endothelial fibrosis and to investigate the underlying mechanism. Primary human endothelial cells were used and pharmacological and short interfering RNA-based approaches were used to test the transforming growth factor beta (TGF-β)/activin receptor-like kinase 5 (ALK5) pathway participation and contribution of TRPM7 ion channel. Suppression of TRPM4 expression leads to decreased endothelial protein expression and increased expression of fibrotic and extracellular matrix markers. Furthermore, TRPM4 downregulation increases intracellular Ca levels as a potential condition for fibrosis. The underlying mechanism of endothelial fibrosis shows that inhibition of TRPM4 expression induces TGF-β1 and TGF-β2 expression, which act through their receptor, ALK5, and the nuclear translocation of the profibrotic transcription factor smad4. TRPM4 acts to maintain endothelial features and its loss promotes fibrotic conversion via TGF-β production. The regulation of TRPM4 levels could be a target for preserving endothelial function during inflammatory diseases.

Degradation prediction model and stem cell growth of gelatin-PEG composite hydrogel.

PubMed

Zhou, Nan; Liu, Chang; Lv, Shijie; Sun, Dongsheng; Qiao, Qinglong; Zhang, Rui; Liu, Yang; Xiao, Jing; Sun, Guangwei

2016-12-01

Gelatin hydrogel has great potential in regenerative medicine. The degradation of gelatin hydrogel is important to control the release profile of encapsulated biomolecules and regulate in vivo tissue repair process. As a plasticizer, PEG can significantly improve the mechanical property of gelatin hydrogel. However, how preparation parameters affect the degradation rate of gelatin-PEG composite hydrogel is still not clear. In this study, the significant effect factor, glutaraldehyde (GA) concentration, was confirmed by means of Plackett-Burman method. Then a mathematical model was built to predict the degradation rate of composite hydrogels under different preparation conditions using the response surface method (RSM), which was helpful to prepare the certain composite hydrogel with desired degradation rate. In addition, it was found that gelatin-PEG composite hydrogel surface well supported the adhesion and growth of human mesenchymal stem cells (MSCs). Moreover, PEG concentration not only could adjust hydrogel degradation more subtly, but also might increase the cross-linking degree and affect the cell migration. Therefore, these results would be useful to optimize the preparation of gelatin-PEG composite hydrogel for drug delivery or tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3149-3156, 2016. © 2016 Wiley Periodicals, Inc.

Decoupling the Functional Pleiotropy of Stem Cell Factor by Tuning c-Kit Signaling

PubMed Central

Ho, Chia Chi M.; Chhabra, Akanksha; Starkl, Philipp; Schnorr, Peter-John; Wilmes, Stephan; Moraga, Ignacio; Kwon, Hye-Sook; Gaudenzio, Nicolas; Sibilano, Riccardo; Wehrman, Tom S.; Gakovic, Milica; Sockolosky, Jonathan T.; Tiffany, Matthew R.; Ring, Aaron M.; Piehler, Jacob; Weissman, Irving L.; Galli, Stephen J.; Shizuru, Judith A.; Garcia, K. Christopher

2017-01-01

SUMMARY Most secreted growth factors and cytokines are functionally pleiotropic because their receptors are expressed on diverse cell types. While important for normal mammalian physiology, pleiotropy limits the efficacy of cytokines and growth factors as therapeutics. Stem cell factor (SCF) is a growth factor that acts through the c-Kit receptor tyrosine kinase to elicit hematopoietic progenitor expansion, but can be toxic when administered in vivo because it concurrently activates mast cells. We engineered a mechanism-based SCF partial agonist that impaired c-Kit dimerization, truncating downstream signaling amplitude. This SCF variant elicited biased activation of hematopoietic progenitors over mast cells in vitro and in vivo. Mouse models of SCF-mediated anaphylaxis, radioprotection, and hematopoietic expansion revealed that this SCF partial agonist retained therapeutic efficacy while exhibiting virtually no anaphylactic off-target effects. The approach of biasing cell activation by tuning signaling thresholds and outputs has applications to many dimeric receptor-ligand systems. PMID:28283060

A tissue engineering approach for prenatal closure of myelomeningocele: comparison of gelatin sponge and microsphere scaffolds and bioactive protein coatings.

PubMed

Watanabe, Miho; Li, Hiaying; Roybal, Jessica; Santore, Matthew; Radu, Antonetta; Jo, Jun-Ichiro; Kaneko, Michio; Tabata, Yasuhiko; Flake, Alan

2011-04-01

Myelomeningocele (MMC) is a common and devastating malformation. As an alternative to fetal surgical repair, tissue engineering has the potential to provide a less invasive approach for tissue coverage applicable at an earlier stage of gestation. We have previously evaluated the use of gelatin hydrogel composites composed of gelatin sponges and sheets as a platform for tissue coverage of the MMC defect in the retinoic acid induced fetal rat model of MMC. In the current study, we compare our previous composite with gelatin microspheres as a scaffold for tissue ingrowth and cellular adhesion within the amniotic fluid environment. We also examine the relative efficacy of various bioactive protein coatings on the adhesion of amniotic fluid cells to the construct within the amniotic cavity. We conclude from this study that gelatin microspheres are as effective as gelatin sponges as a scaffold for cellular ingrowth and amniotic fluid cell adhesion and that collagen type I and fibronectin coatings enhance amniotic fluid cell adhesion to the gelatin-based scaffolds. These findings support the potential for the development of a tissue-engineered injectable scaffold that could be applied by ultrasound-guided injection, much earlier and less invasively than sponge or sheet-based composites.

Use and application of gelatin as potential biodegradable packaging materials for food products.

PubMed

Nur Hanani, Z A; Roos, Y H; Kerry, J P

2014-11-01

The manufacture and potential application of biodegradable films for food application has gained increased interest as alternatives to conventional food packaging polymers due to the sustainable nature associated with their availability, broad and abundant source range, compostability, environmentally-friendly image, compatibility with foodstuffs and food application, etc. Gelatin is one such material and is a unique and popularly used hydrocolloid by the food industry today due to its inherent characteristics, thereby potentially offering a wide range of further and unique industrial applications. Gelatin from different sources have different physical and chemical properties as they contain different amino acid contents which are responsible for the varying characteristics observed upon utilization in food systems and when being utilized more specifically, in the manufacture of films. Packaging films can be successfully produced from all gelatin sources and the behaviour and characteristics of gelatin-based films can be altered through the incorporation of other food ingredients to produce composite films possessing enhanced physical and mechanical properties. This review will present the current situation with respect to gelatin usage as a packaging source material and the challenges that remain in order to move the manufacture of gelatin-based films nearer to commercial reality. Copyright © 2014 Elsevier B.V. All rights reserved.

Preparation and physicochemistry properties of smart edible films based on gelatin-starch nanoparticles.

PubMed

Tao, Furong; Shi, Chengmei; Cui, Yuezhi

2018-04-24

Among the natural polymers able to form edible films, starch and gelatin (Gel) are potential sources. Corn starch is a polysaccharide widely produced around the world, and gelatin differs from other hydrocolloids as a fully digestible protein, containing nearly all the essential amino acids, except tryptophan. Based on this, with advantages such as abundance, relatively low cost, biodegradability, and edibility, studies considering alternative systems for food protection that utilize biopolymers have increased significantly in the recent years. A novel macromolecular crosslinker Starch-BTCAD-NHS (starch - butanetetracarboxylic acid dianhydride - N-hydroxysuccinimide, SBN) was successfully prepared to modify gelatin film. Compared with the blank gelatin films, the resulting SBN-Gel films exhibited the improved surface hydrophobicity, the higher tense strength and elongation-at-break, the lower Young's modulus values, the greater opacity, the poorer water vapor uptake properties and better anti-degradation capacity. The modified gelatin film material with advanced properties obtained in this work was safe, stable eco-friendly and biorefractory, and was an ideal choice to form a packaging in food industry. Also, the crosslinking SBN-gelatin coating was effective in reducing the corruption and extending the shelf life for the peeled apple substantially. This article is protected by copyright. All rights reserved.

Targeted gene expression profiling in European sea bass (Dicentrarchus labrax, L.) follicles from primary growth to late vitellogenesis.

PubMed

García-López, Angel; Sánchez-Amaya, María Isabel; Prat, Francisco

2011-11-01

A real-time PCR-based gene expression survey was performed on isolated European sea bass follicles from primary growth to late vitellogenesis. Expression levels of 18 transcripts with demonstrated relevance during oogenesis, encoding gonadotropin, thyrotropin, estrogen, androgen, and vitellogenin receptors, steroidogenesis-related as well as growth and transcription factors were measured. Primary oocytes showed high mRNA levels of insulin-like growth factors 1 and 2, bone morphogenetic protein 4, estrogen receptor 2b, androgen receptor b, and SRY-box containing gene 17 together with low transcript amounts of gonadotropin receptors. Follicles at the lipid vesicles stage (i.e., the beginning of the secondary growth phase) showed elevated mRNA amounts of follicle stimulating hormone receptor (fshr) and anti-Mullerian hormone. Early-to-mid vitellogenic follicles showed high mRNA levels of fshr and cytochrome P450, family 19, subfamily A, polypeptide 1a while mid-to-late vitellogenic follicles expressed increasing transcript amounts of luteinizing hormone/choriogonadotropin receptor, steroidogenic acute regulatory protein, and estrogen receptors 1 and 2a. The molecular data presented here may serve as a solid base for future studies focused on unraveling the specific mechanisms orchestrating follicular development in teleost fish. Copyright © 2011 Elsevier Inc. All rights reserved.

Inhibiting the Epidermal Growth Factor Receptor | Center for Cancer Research

Cancer.gov

The Epidermal Growth Factor Receptor (EGFR) is a widely distributed cell surface receptor that responds to several extracellular signaling molecules through an intracellular tyrosine kinase, which phosphorylates target enzymes to trigger a downstream molecular cascade. Since the discovery that EGFR mutations and amplifications are critical in a number of cancers, efforts have

Tyrosine dephosphorylation enhances the therapeutic target activity of epidermal growth factor receptor (EGFR) by disrupting its interaction with estrogen receptor (ER).

PubMed

Ma, Shao; Yin, Ning; Qi, Xiaomei; Pfister, Sandra L; Zhang, Mei-Jie; Ma, Rong; Chen, Guan

2015-05-30

Protein-protein interactions can increase or decrease its therapeutic target activity and the determining factors involved, however, are largely unknown. Here, we report that tyrosine-dephosphorylation of epidermal growth factor receptor (EGFR) increases its therapeutic target activity by disrupting its interaction with estrogen receptor (ER). Protein tyrosine phosphatase H1 (PTPH1) dephosphorylates the tyrosine kinase EGFR, disrupts its interaction with the nuclear receptor ER, and increases breast cancer sensitivity to small molecule tyrosine kinase inhibitors (TKIs). These effects require PTPH1 catalytic activity and its interaction with EGFR, suggesting that the phosphatase may increase the sensitivity by dephosphorylating EGFR leading to its dissociation with ER. Consistent with this notion, a nuclear-localization defective ER has a higher EGFR-binding activity and confers the resistance to TKI-induced growth inhibition. Additional analysis show that PTPH1 stabilizes EGFR, stimulates the membranous EGFR accumulation, and enhances the growth-inhibitory activity of a combination therapy of TKIs with an anti-estrogen. Since EGFR and ER both are substrates for PTPH1 in vitro and in intact cells, these results indicate that an inhibitory EGFR-ER protein complex can be switched off through a competitive enzyme-substrate binding. Our results would have important implications for the treatment of breast cancer with targeted therapeutics.

Androgen Receptor: A Complex Therapeutic Target for Breast Cancer

PubMed Central

Narayanan, Ramesh; Dalton, James T.

2016-01-01

Molecular and histopathological profiling have classified breast cancer into multiple sub-types empowering precision treatment. Although estrogen receptor (ER) and human epidermal growth factor receptor (HER2) are the mainstay therapeutic targets in breast cancer, the androgen receptor (AR) is evolving as a molecular target for cancers that have developed resistance to conventional treatments. The high expression of AR in breast cancer and recent discovery and development of new nonsteroidal drugs targeting the AR provide a strong rationale for exploring it again as a therapeutic target in this disease. Ironically, both nonsteroidal agonists and antagonists for the AR are undergoing clinical trials, making AR a complicated target to understand in breast cancer. This review provides a detailed account of AR’s therapeutic role in breast cancer. PMID:27918430

Incorporation of mesoporous silica nanoparticles into random electrospun PLGA and PLGA/gelatin nanofibrous scaffolds enhances mechanical and cell proliferation properties.

PubMed

Mehrasa, Mohammad; Asadollahi, Mohammad Ali; Nasri-Nasrabadi, Bijan; Ghaedi, Kamran; Salehi, Hossein; Dolatshahi-Pirouz, Alireza; Arpanaei, Ayyoob

2016-09-01

Poly(lactic-co-glycolic acid) (PLGA) and PLGA/gelatin random nanofibrous scaffolds embedded with different amounts of mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. To evaluate the effects of nanoparticles on the scaffolds, physical, chemical, and mechanical properties as well as in vitro degradation behavior of scaffolds were investigated. The mean diameters of nanofibers were 974±68nm for the pure PLGA scaffolds vs 832±70, 764±80, and 486±64 for the PLGA/gelatin, PLGA/10wt% MSNPs, and the PLGA/gelatin/10wt% MSNPs scaffolds, respectively. The results suggested that the incorporation of gelatin and MSNPs into PLGA-based scaffolds enhances the hydrophilicity of scaffolds due to an increase of hydrophilic functional groups on the surface of nanofibers. With porosity examination, it was concluded that the incorporation of MSNPs and gelatin decrease the porosity of scaffolds. Nanoparticles also improved the tensile mechanical properties of scaffolds. Using in vitro degradation analysis, it was shown that the addition of nanoparticles to the nanofibers matrix increases the weight loss percentage of PLGA-based samples, whereas it decreases the weight loss percentage in the PLGA/gelatin composites. Cultivation of rat pheochromocytoma cell line (PC12), as precursor cells of dopaminergic neural cells, on the scaffolds demonstrated that the introduction of MSNPs into PLGA and PLGA/gelatin matrix leads to improved cell attachment and proliferation and enhances cellular processes. Copyright © 2016 Elsevier B.V. All rights reserved.

Mechanisms of disease: understanding resistance to HER2-targeted therapy in human breast cancer.

PubMed

Nahta, Rita; Yu, Dihua; Hung, Mien-Chie; Hortobagyi, Gabriel N; Esteva, Francisco J

2006-05-01

Trastuzumab is a monoclonal antibody targeted against the human epidermal growth factor receptor (HER) 2 tyrosine kinase receptor, which is overexpressed in approximately 25% of invasive breast cancers. The majority of patients with metastatic breast cancer who initially respond to trastuzumab, however, demonstrate disease progression within 1 year of treatment initiation. Preclinical studies have indicated several molecular mechanisms that could contribute to the development of trastuzumab resistance. Increased signaling via the phosphatidylinositol 3-kinase/Akt pathway could contribute to trastuzumab resistance because of activation of multiple receptor pathways that include HER2-related receptors or non-HER receptors such as the insulin-like growth factor 1 receptor, which appears to be involved in a cross-talk with HER2 in resistant cells. Additionally, loss of function of the tumor suppressor PTEN gene, the negative regulator of Akt, results in heightened Akt signaling that leads to decreased sensitivity to trastuzumab. Decreased interaction between trastuzumab and its target receptor HER2, which is due to steric hindrance of HER2 by cell surface proteins such as mucin-4 (MUC4), may block the inhibitory actions of trastuzumab. Novel therapies targeted against these aberrant molecular pathways offer hope that the effectiveness and duration of response to trastuzumab can be greatly improved.

Multicolor fluorescence "click"-chemistry as a means to select membrane targets for pre-targeting approaches by function of their receptor kinetics.

PubMed

van der Wal, Steffen; de Korne, Clarize M; Sand, Laurens L G; van Willigen, Danny M; Hogendoorn, Pancras C W; Szuhai, Karoly; van Leeuwen, Fijs W B; Buckle, Tessa

2018-06-04

Availability of a receptor for theranostic pre-targeting approaches was assessed using a novel "click" chemistry-based de-activatable fluorescence-quenching concept. Efficacy was evaluated in a cell-based model system that exhibits both membranous (available) and internalized (unavailable) receptor-fractions of the clinically relevant receptor chemokine receptor 4 (CXCR4). Proof of concept was based on a de-activatable tracer consisting out of a CXCR4 specific peptide functionalized with a Cy5 dye comprising a chemo-selective azide handle (N3-Cy5-AcTZ14011). Reaction with a Cy7 quencher dye (Cy7-DBCO) resulted in optically silent Cy7-["click"]-Cy5-AcTZ14011. In situ a >90% FRET-based reduction of signal intensity of N3-Cy5-AcTZ14011 (KD 222.4 ± 25.2 nM) was seen within minutes after quencher addition. In cells, discrimination between the membranous and internalized receptor-fraction could be made through quantitative assessment of quenching/internalization kinetics. As such, using this approach screening of membrane receptors and their applicability in receptor-(pre-)targeted theranostics can become straightforward. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gelatin-hydroxypropyl methylcellulose water-in-water emulsions as a new bio-based packaging material.

PubMed

Esteghlal, Sara; Niakosari, Mehrdad; Hosseini, Seyed Mohammad Hashem; Mesbahi, Gholam Reza; Yousefi, Gholam Hossein

2016-05-01

Gelatin and hydroxypropyl methylcellulose (HPMC) are two incompatible and immiscible biopolymers which cannot form homogeneous composite films using usual methods. In this study, to prevent phase separation, gelatin-HPMC water-in-water (W/W) emulsion was utilized to from transparent composite films by entrapment the HPMC dispersed droplets in gelatin continuous network. The physicochemical and mechanical properties of emulsion-based films containing different amounts (5-30%) of dispersed phase were determined and compared with those of individual polymer-based films. Incorporating HPMC into W/W emulsion-based films had no significant effect on the tensile strength. The flexibility of composite films decreased at HPMC concentrations below 20%. The depletion layer at the droplets interface reduced the diffusion of water vapor molecules because of its hydrophobic nature, so the water vapor permeability remained constant. Increasing the HPMC content in the emulsion films increased the swelling and decreased the transparency. The entrapment of HPMC in continuous gelatin phase decreased its solubility. Therefore, W/W emulsions are capable of holding two incompatible polymers alongside each other within a homogeneous film network without weakening the physical properties. Copyright © 2016 Elsevier B.V. All rights reserved.

Novel formulations of ballistic gelatin. 1. Rheological properties.

PubMed

Zecheru, Teodora; Său, Ciprian; Lăzăroaie, Claudiu; Zaharia, Cătălin; Rotariu, Traian; Stănescu, Paul-Octavian

2016-06-01

Ballistic gelatin is the simulant of the human body during field tests in forensics and other related fields, due to its physical and mechanical similarities to human trunk and organs. Since the ballistic gelatin used in present has important issues to overcome, an alternative approach is the use of gelatin-polymer composites, where a key factor is the insertion of biocompatible materials, which replicate accurately the human tissues. In order to be able to obtain an improved material in terms of mechanical performances by an easy industrial-scale technology, before the verification of the ballistic parameters by shooting in agreement with military standards, one of the best and cheapest solutions is to perform a thorough check of their rheological properties, in standard conditions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Gelation and thermal characteristics of microwave extracted fish gelatin-natural gum composite gels.

PubMed

Binsi, P K; Nayak, Natasha; Sarkar, P C; Joshy, C G; Ninan, George; Ravishankar, C N

2017-02-01

In this study, the gelation and thermal characteristics of microwave extracted fish scale gelatin blended with natural gums such as gum arabic (AG), xanthan gum (XG), guar gum (GG), and tragacanth gum (TG) was evaluated. The nature of interaction and behavior of gelatin in presence of various gums was confirmed by particle size analysis, viscosity profile, FT-IR analysis and turbidity measurements. DSC data revealed that addition of AG, TG and GG remarkably improved the thermal stability of fish gelatin gel. The composite gels of TG, AG, and XG exhibited higher hardness and bloom strength values as compared to pure fish gelatin implying its textural synergy. Based on qualitative descriptive analysis, TG was found to be superior in improving the stability of fish gelatin gel, closely followed by AG. The results suggest that addition of these gums can reduce syneresis and retard melting of gelatin gels at ambient temperature, which are otherwise soft and thermally unstable.

Gelatin based bio-films prepared from grey triggerfish' skin influenced by enzymatic pretreatment.

PubMed

Souissi, Nabil; Abdelhedi, Ola; Mbarek, Aïcha; Kammoun, Wassim; Kechaou, Hela; Nasri, Moncef

2017-12-01

Gelatins from grey triggerfish skin were extracted with different methods. The treatment by pepsin (PG) improved the yield of extraction when compared with untreated gelatin (UG) and acidic gelatin (AG). The outputs of gelatins AG, UG and PG, obtained respectively, with acitic acid, glycine buffer and glycine buffer added with 5U of pepsin/g of the skin beforehand treated by alkali, were 6.9%, 7.9% and 9.7%, respectively. The enzymatic treatment of the alkali-pretreated skin of grey triggerfish altered the electrophoresis profile, biophysical, gellification, rheological and thermal properties of the prepared gelatins extracted under acidic condition. However, the untreated gelatin obtained without pepsin exhibited the highest transition and enthaply temperatures. In addition, the properties of the prepared films were interconnected to their microstructure as demonstrated by scanning electron microscopy. Furthermore, films with PG and UG had a regular surface and a more condensed structure, whereas films prepared with AG had rougher surface. Copyright © 2017 Elsevier B.V. All rights reserved.

Potential Use in Forensics of a Novel Hybrid Gelatin-Dynamic Impact Assessment.

PubMed

Zecheru, Teodora; Dena, Alexandru; Cîrmaci, Marius; Său, Ciprian; Zaharia, Cătălin; Lăzăroaie, Claudiu

2018-05-01

Ballistic gelatin as simulant of the human body and organs is a support in forensics. After having obtained very good results for a new gelatin-based composite in terms of physicochemical and rheological properties, this study focused on this material's mechanical behavior during stabbing and shooting versus bovine and porcine organs and standard ballistic gelatin. The hybrid gelatin has a predominantly elastic behavior at 23°C, whereas the elastic modulus becomes practically constant in the 10-0.1 Hz frequency range. In terms of stabbing behavior, the small variations obtained between porcine organs and surrogate are below 5%, the perforation indicating a good similarity. From the ballistic test results using 10 × 28T rubber balls, it has been seen that the hybrid ballistic gelatin conducts to more reliable and reproducible values of perforation/penetration versus standard gelatin, making from it a real candidate for use in forensic tests. © 2017 American Academy of Forensic Sciences.

Structural studies on aqueous gelatin solutions: Implications in designing a thermo-responsive nanoparticulate formulation.

PubMed

Ahsan, Saad M; Rao, Ch Mohan

2017-02-01

Gelatin as a polymer has found extensive application in the pharmaceutical industry. It is also being used, as a matrix molecule, for nanoparticle based drug delivery applications. Gelatin nanoparticles synthesised, keeping the native structure intact, show interesting properties. Synthesizing such nanoparticles requires an understanding of the structural features of gelatin under conditions of nanoparticle synthesis and preserving them during the process. To address this we have carried out an extensive characterization of gelatin using circular dichroism (CD) spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) under various reaction conditions that are utilized in the desolvation method for gelatin nanoparticle synthesis. We investigated the gel-sol transition, hysteresis and gelatin fibre morphology under different pH and temperature conditions. We also investigated the temperature and pH dependence of triple-helix to random-coil transition in gelatin. We finally demonstrate the synthesis of gelatin nanoparticles with native gelatin. These nanoparticles show shrinkage in size (∼90nm) with increase in temperature from 30°C (369.4 ±19.8) to 40°C (282.3±9.8). Our results suggest that by carefully selecting the reaction conditions, it is possible to synthesise nanoparticles having partially folded structures and with a varying degree of sensitivity towards temperature and pH. Copyright © 2016 Elsevier B.V. All rights reserved.

Increasing Elasticity through Changes in the Secondary Structure of Gelatin by Gelation in a Microsized Lipid Space.

PubMed

Sakai, Atsushi; Murayama, Yoshihiro; Fujiwara, Kei; Fujisawa, Takahiro; Sasaki, Saori; Kidoaki, Satoru; Yanagisawa, Miho

2018-04-25

Even though microgels are used in a wide variety of applications, determining their mechanical properties has been elusive because of the difficulties in analysis. In this study, we investigated the surface elasticity of a spherical microgel of gelatin prepared inside a lipid droplet by using micropipet aspiration. We found that gelation inside a microdroplet covered with lipid membranes increased Young's modulus E toward a plateau value E * along with a decrease in gel size. In the case of 5.0 wt % gelatin gelled inside a microsized lipid space, the E * for small microgels with R ≤ 50 μm was 10-fold higher (35-39 kPa) than that for the bulk gel (∼3 kPa). Structural analysis using circular dichroism spectroscopy and a fluorescence indicator for ordered beta sheets demonstrated that the smaller microgels contained more beta sheets in the structure than the bulk gel. Our finding indicates that the confinement size of gelling polymers becomes a factor in the variation of elasticity of protein-based microgels via secondary structure changes.

Increasing Elasticity through Changes in the Secondary Structure of Gelatin by Gelation in a Microsized Lipid Space

PubMed Central

2018-01-01

Even though microgels are used in a wide variety of applications, determining their mechanical properties has been elusive because of the difficulties in analysis. In this study, we investigated the surface elasticity of a spherical microgel of gelatin prepared inside a lipid droplet by using micropipet aspiration. We found that gelation inside a microdroplet covered with lipid membranes increased Young’s modulus E toward a plateau value E* along with a decrease in gel size. In the case of 5.0 wt % gelatin gelled inside a microsized lipid space, the E* for small microgels with R ≤ 50 μm was 10-fold higher (35–39 kPa) than that for the bulk gel (∼3 kPa). Structural analysis using circular dichroism spectroscopy and a fluorescence indicator for ordered beta sheets demonstrated that the smaller microgels contained more beta sheets in the structure than the bulk gel. Our finding indicates that the confinement size of gelling polymers becomes a factor in the variation of elasticity of protein-based microgels via secondary structure changes. PMID:29721530

Prolonged Culture of Aligned Skeletal Myotubes on Micromolded Gelatin Hydrogels

PubMed Central

Bettadapur, Archana; Suh, Gio C.; Geisse, Nicholas A.; Wang, Evelyn R.; Hua, Clara; Huber, Holly A.; Viscio, Alyssa A.; Kim, Joon Young; Strickland, Julie B.; McCain, Megan L.

2016-01-01

In vitro models of skeletal muscle are critically needed to elucidate disease mechanisms, identify therapeutic targets, and test drugs pre-clinically. However, culturing skeletal muscle has been challenging due to myotube delamination from synthetic culture substrates approximately one week after initiating differentiation from myoblasts. In this study, we successfully maintained aligned skeletal myotubes differentiated from C2C12 mouse skeletal myoblasts for three weeks by utilizing micromolded (μmolded) gelatin hydrogels as culture substrates, which we thoroughly characterized using atomic force microscopy (AFM). Compared to polydimethylsiloxane (PDMS) microcontact printed (μprinted) with fibronectin (FN), cell adhesion on gelatin hydrogel constructs was significantly higher one week and three weeks after initiating differentiation. Delamination from FN-μprinted PDMS precluded robust detection of myotubes. Compared to a softer blend of PDMS μprinted with FN, myogenic index, myotube width, and myotube length on μmolded gelatin hydrogels was similar one week after initiating differentiation. However, three weeks after initiating differentiation, these parameters were significantly higher on μmolded gelatin hydrogels compared to FN-μprinted soft PDMS constructs. Similar results were observed on isotropic versions of each substrate, suggesting that these findings are independent of substrate patterning. Our platform enables novel studies into skeletal muscle development and disease and chronic drug testing in vitro. PMID:27350122

Skin problems and EGFR-tyrosine kinase inhibitor

PubMed Central

Kozuki, Toshiyuki

2016-01-01

Epidermal growth factor receptor inhibition is a good target for the treatment of lung, colon, pancreatic and head and neck cancers. Epidermal growth factor receptor-tyrosine kinase inhibitor was first approved for the treatment of advanced lung cancer in 2002. Epidermal growth factor receptor-tyrosine kinase inhibitor plays an essential role in the treatment of cancer, especially for patients harbouring epidermal growth factor receptor activating mutation. Hence, skin toxicity is the most concerning issue for the epidermal growth factor receptor-tyrosine kinase inhibitor treatment. Skin toxicity is bothersome and sometimes affects the quality of life and treatment compliance. Thus, it is important for physicians to understand the background and how to manage epidermal growth factor receptor-tyrosine kinase inhibitor-associated skin toxicity. Here, the author reviewed the mechanism and upfront preventive and reactive treatments for epidermal growth factor receptor inhibitor-associated skin toxicities. PMID:26826719

Effect of silver nanoparticles on the spectral luminescent properties of a gelatin film

NASA Astrophysics Data System (ADS)

Efendiev, T. Sh.; Kruchenok, J. V.; Rubinov, A. N.

2013-03-01

We studied the absorption and fluorescence spectra of a rhodamine 6G-activated gelatin film of thickness 10 μm, with and without silver nanoparticles. We observed that doping the film with nanoparticles of diameter 5 nm leads to an increase in the intensity of the absorption spectrum by a factor of 1.17 and its short-wavelength shift (~1.5 nm), while the intensity of the fluorescence spectrum increases by a factor of ~2.

Virtual Prototyping for Personal Protective Equipment and Workplaces

DTIC Science & Technology

1999-03-01

Basket Weave Kevlar-29 Fabric Loosely Draped over 20% Ordnance Gelatin Block Subject to Non-Perforating Impact by .38 Special (130-grain FMJ...Fabric and fabric-like materials are very difficult to model because of the dynamic properties of folding, draping , and stretching. How these...Targets Bare Targets with Insitu Instrumentation V7 Instrumented Targets with Loosely Draped Clothing SL Instrumented Targets with Body Armor

Preliminary Estimate for Injury Criterion to Immediate Incapacitation by Projectile Penetration

DTIC Science & Technology

2012-01-01

tissues with different mechanical properties. The questions then arise: How representative of the real target is ballistic gelatine and how does the...of penetration of a typical fragment at varying velocity was computed. The characteristics of different tissues composing the human torso and their...based on the observation that to hit critical organs (the CNS as well as the heart and large arteries), 30 to 45 cm of tissues (human or animal) has

Nuclear receptors in pancreatic tumor cells.

PubMed

Damaskos, Christos; Garmpis, Nikolaos; Karatzas, Theodore; Kostakis, Ioannis D; Nikolidakis, Lampros; Kostakis, Alkiviadis; Kouraklis, Gregory

2014-12-01

This review focuses on nuclear receptors expressed in pancreatic cancer. An extensive search of articles published up to March 2013 was conducted using the MEDLINE database. The key words used were "pancreatic cancer", "molecular receptors" and "growth factors". A total of 112 articles referred to pancreatic cancer, molecular receptors and/or growth factors were included. Receptors of growth factors, such as the epithelial growth factor receptor, insulin-like growth factor-1 receptor, vascular endothelial growth factor receptor and others, such as integrin α5β1, somatostatin receptors, the death receptor 5, claudin, notch receptors, mesothelin receptors, follicle-stimulating hormone receptors, the MUC1 receptor, the adrenomedullin receptor, the farnesoid X receptor, the transferrin receptor, sigma-2 receptors, the chemokine receptor CXCR4, the urokinase plasminogen activator receptor, the ephrine A2 receptor, the GRIA3 receptor, the RON receptor and the angiotensin II receptor AT-1 are expressed in pancreatic tumor cells. These molecules are implicated in tumor growth, apoptosis, angiogenesis, metastasis etc. After identifying the molecular receptors associated with the pancreatic cancer, many more target molecules playing important roles in tumor pathophysiology and senescence-associated signal transduction in cancer cells will be identified. This may have a significant influence on diagnosis, therapy and prognosis of pancreatic cancer. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Preparation of dumbbell manganese dioxide/gelatin composites and their application in the removal of lead and cadmium ions.

PubMed

Wang, Xiu; Huang, Kai; Chen, Ying; Liu, Jiafa; Chen, Shan; Cao, Jianlei; Mei, Surong; Zhou, Yikai; Jing, Tao

2018-05-15

The nano-sized sorbents restrict their practical application in flow-through system due to excessive pressure. In this study, dumbbell MnO 2 /gelatin composites were synthesized based on the protein-assisted synthesis technology. Then they were immobilized on the amino-modified polymethyl methacrylate (PMMA) plate. SEM, TEM, XRD, XPS and FT-IR were employed to study the surface properties and the adsorption mechanism of MnO 2 /gelatin composites. Adsorption experiments for Pb(II) and Cd(II) ions were performed to study the adsorption isotherms, kinetics, and thermodynamics as well as the influencing factors. The maximum adsorption capacities of Pb(II) and Cd(II) ions were 318.7 mg g -1 and 105.1 mg g -1 respectively. The adsorption process met the pseudo-second-order kinetic model. Subsequently, MnO 2 /gelatin composites modified plates were used to remove the heavy metal ions in surface water and wastewater samples. The removal efficiencies of Pb(II) ion was changed from 83% (wastewater) to 100% (surface water), when the initial concentration was 10 mg L -1 . This device exhibited great application prospect in the removal of heavy metals taking advantage of its high removal efficiency, excellent stability and reusability and ease of operation. Copyright © 2018 Elsevier B.V. All rights reserved.

Kruppel-like Factor 9 is a Negative Regulator of Ligand-dependent Estrogen Receptor Alpha Signaling in Ishikawa Endometrial Adenocarcinoma Cells

USDA-ARS?s Scientific Manuscript database

Estrogen (E) and progesterone (P), acting through their respective receptors and other nuclear proteins, exhibit opposing activities in target cells. We previously reported that Krüppel-like factor 9 (KLF9) cooperates with progesterone receptor (PR) to facilitate P-dependent gene transcription in ut...

Epidermal Growth Factor Receptor targeting in non-small cell lung cancer: revisiting different strategies against the same target.

PubMed

Castañón, Eduardo; Martín, Patricia; Rolfo, Christian; Fusco, Juan P; Ceniceros, Lucía; Legaspi, Jairo; Santisteban, Marta; Gil-Bazo, Ignacio

2014-01-01

Epidermal Growth Factor Receptor (EGFR) tyrosine kinase inhibitors (TKIs) have changed the paradigm of treatment in non-small cell lung cancer (NSCLC). The molecular biology study of EGFR has led to clinical trials that select patients more accurately, regarding the presence of EGFR activating mutations. Nonetheless, a lack of response or a temporary condition of the response has been detected in patients on EGFR TKIs. This has urged to study potential resistance mechanisms underneath. The most important ones are the presence of secondary mutations in EGFR, such as T790M, or the overexpression of mesenchymal-epithelial transition factor (MET) that may explain why patients who initially respond to EGFR TKIs, may ultimately become refractory. Several approaches have been taken and new drugs both targeting EGFR resistance-mutation or MET are currently being developed. Here we review and update the EGFR biological pathway as well as the clinical data leading to approval of the EGFR TKIs currently in the market. New compounds under investigation targeting resistance mutations or dually targeting EGFR and other relevant receptors are also reviewed and discussed.

Targeting Epidermal Growth Factor Receptor in triple negative breast cancer: New discoveries and practical insights for drug development.

PubMed

Costa, Ricardo; Shah, Ami N; Santa-Maria, Cesar A; Cruz, Marcelo R; Mahalingam, Devalingam; Carneiro, Benedito A; Chae, Young Kwang; Cristofanilli, Massimo; Gradishar, William J; Giles, Francis J

2017-02-01

Triple negative breast cancer (TNBC) accounts for 10-20% of cases in breast cancer. Despite recent advances in the treatment of hormonal receptor+ and HER2+ breast cancers, there are no targeted therapies available for TNBC. Evidence supports that most patients with TNBC express the transmembrane Epidermal Growth Factor Receptor (EGFR). However, early phase clinical trials failed to demonstrate significant activity of EGFR-targeted monoclonal antibodies and/or tyrosine kinase inhibitors. Here, we review the recent discoveries related to the underlying biology of the EGFR pathway in TNBC, clinical progress to date and suggest rational future approaches for investigational therapies in TNBC. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Plant Immune Receptor Detects Pathogen Effectors that Target WRKY Transcription Factors.

PubMed

Sarris, Panagiotis F; Duxbury, Zane; Huh, Sung Un; Ma, Yan; Segonzac, Cécile; Sklenar, Jan; Derbyshire, Paul; Cevik, Volkan; Rallapalli, Ghanasyam; Saucet, Simon B; Wirthmueller, Lennart; Menke, Frank L H; Sohn, Kee Hoon; Jones, Jonathan D G

2015-05-21

Defense against pathogens in multicellular eukaryotes depends on intracellular immune receptors, yet surveillance by these receptors is poorly understood. Several plant nucleotide-binding, leucine-rich repeat (NB-LRR) immune receptors carry fusions with other protein domains. The Arabidopsis RRS1-R NB-LRR protein carries a C-terminal WRKY DNA binding domain and forms a receptor complex with RPS4, another NB-LRR protein. This complex detects the bacterial effectors AvrRps4 or PopP2 and then activates defense. Both bacterial proteins interact with the RRS1 WRKY domain, and PopP2 acetylates lysines to block DNA binding. PopP2 and AvrRps4 interact with other WRKY domain-containing proteins, suggesting these effectors interfere with WRKY transcription factor-dependent defense, and RPS4/RRS1 has integrated a "decoy" domain that enables detection of effectors that target WRKY proteins. We propose that NB-LRR receptor pairs, one member of which carries an additional protein domain, enable perception of pathogen effectors whose function is to target that domain. Copyright © 2015 Elsevier Inc. All rights reserved.

Emerging growth factor receptor antagonists for the treatment of renal cell carcinoma.

PubMed

Zahoor, Haris; Rini, Brian I

2016-12-01

The landscape of systemic treatment for metastatic renal cell carcinoma (RCC) has dramatically changed with the introduction of targeted agents including vascular endothelial growth factor (VEGF) inhibitors. Recently, multiple new agents including growth factor receptor antagonists and a checkpoint inhibitor were approved for the treatment of refractory metastatic RCC based on encouraging benefit shown in clinical trials. Areas covered: The background and biological rationale of existing treatment options including a brief discussion of clinical trials which led to their approval, is presented. This is followed by reviewing the limitations of these therapeutic options, medical need to develop new treatments and major goals of ongoing research. We then discuss two recently approved growth factor receptor antagonists i.e. cabozantinib and lenvatinib, and a recently approved checkpoint inhibitor, nivolumab, and issues pertaining to drug development, and future directions in treatment of metastatic RCC. Expert opinion: Recently approved growth factor receptor antagonists have shown encouraging survival benefit but associated drug toxicity is a major issue. Nivolumab, a programmed death 1 (PD-1) checkpoint inhibitor, has similarly shown survival benefit and is well tolerated. With multiple options now available in this patient population, the right sequence of these agents remains to be determined.

Glycation and transglutaminase mediated glycosylation of fish gelatin peptides with glucosamine enhance bioactivity.

PubMed

Hong, Pui Khoon; Gottardi, Davide; Ndagijimana, Maurice; Betti, Mirko

2014-01-01

A mixture of novel glycopeptides from glycosylation between cold water fish skin gelatin hydrolysates and glucosamine (GlcN) via transglutaminase (TGase), as well as glycation between fish gelatin hydrolysate and GlcN were identified by their pattern of molecular distribution using MALDI-TOF-MS. Glycated/glycosylated hydrolysates showed superior bioactivity to their original hydrolysates. Alcalase-derived fish skin gelatin hydrolysate glycosylated with GlcN in the presence of TGase at 25°C (FAT25) possessed antioxidant activity when tested in a linoleic acid oxidation system, when measured according to its 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and when tested at the cellular level with human hepatocarcinoma (HepG2) cells as target cells. In addition, Alcalase-derived glycosylated hydrolysates showed specificity toward the inhibition of Escherichia coli (E. coli). The Flavourzyme-derived glycopeptides prepared at 37°C (FFC37 and FFT37) showed better DPPH scavenging activity than their native hydrolysates. The glycated Flavourzyme-derived hydrolysates were found to act as potential antimicrobial agents when incubated with E. coli and Bacillus subtilis. Copyright © 2013 Elsevier Ltd. All rights reserved.

Carboxymethylated ɩ-carrageenan conjugated amphotericin B loaded gelatin nanoparticles for treating intracellular Candida glabrata infections.

PubMed

Aparna, V; Melge, Anu Rohit; Rajan, V K; Biswas, Raja; Jayakumar, R; Gopi Mohan, C

2018-04-15

Intercellular Candida glabrata infections are difficult to treat due to poor penetration of drugs into the fungal niche. Delivering amphotericin B (Amp B) into the macrophages where the pathogen inhabits is an effective solution. We are studying the macrophage targeting proficiency of ɩ-carrageenan for the delivery of Amp B using gelatin A nanoparticles (GNPs). The choice of gelatin A was the outcome of in silico inspections where the amino functionalized polymer having the best docking score with Amp B was selected. We prepared a sustained release formulation of amp B loaded carboxymethyl ɩ-carrageenan conjugated gelatin nanoparticles (CMC-Amp B-GNPs) with size 343±12nm and -25±5.3mV zeta potential. The formulations were found to be stable, biocompatible and non-haemolytic. Flow cytometry analysis showed 3 fold higher uptake of CMC-GNPs compared to the GNPs by RAW 264.7 cells. CMC-Amp B-GNPs showed enhanced antifungal activity than bare Amp B and Amp B-GNPs. Copyright © 2017 Elsevier B.V. All rights reserved.

Buffer capacity of 4% succinylated gelatin does not provide any advantages over acidic 6% hydroxyethyl starch 130/0.4 for acid-base balance during experimental mixed acidaemia in a porcine model.

PubMed

Esche, V; Russ, M; Melzer, S; Grossmann, B; Boemke, W; Unger, J K

2008-11-01

Four percent gelatine is an alkaline compound due to NH2 groups, whereas 6% hydroxyethyl starch 130/0.4 (HES130) has acidic features. We investigated whether these solutions lead to differences in acid-base balance in pigs during acidaemia and correction of pH. Anaesthetized pigs were randomized to HES130 or gelatine infusion (n = 5 per group). Animals received acid infusion (0.4 M solution of lactic acid and HCl diluted in normal saline) and low tidal volume ventilation (6-7 mL kg(-1), PaCO2 of 80-85 mmHg, pH 7.19-7.24). Measurements were made before and after induction of acidaemia, before and after correction of pH with haemofiltration (continuous venovenous haemofiltration) and tris-hydroxymethylaminomethane infusion. We measured parameters describing acid-base balance according to Stewart's approach, ketone body formation, oxygen delivery, haemodynamics, diuresis and urinary pH. Acid-base balance did not differ significantly between the groups. In HES130-treated pigs, the haemodilution-based drop of haemoglobin (1.4 +/- 1.0 g dL(-1), median +/- SD) was paralleled by an increase in the cardiac output (0.5 +/- 0.4 L min(-1). Lacking increases in cardiac output, gelatine-treated pigs demonstrated a reduction in oxygen delivery (149.4 +/- 106.0 mL min(-1)). Tris-hydroxymethylaminomethane volumes required for pH titration to desired values were significantly higher in the gelatine group (0.7 +/- 0.1 mL kg(-1) h(-1) vs. HES130: 0.5 +/- 0.2 mL kg(-1) h(-1)). The buffer capacity of gelatine did not lead to favourable differences in acid-base balance in comparison to HES130.

Early clinical development of epidermal growth factor receptor targeted therapy in breast cancer.

PubMed

Matsuda, Naoko; Lim, Bora; Wang, Xiaoping; Ueno, Naoto T

2017-04-01

Epidermal growth factor receptor (EGFR) targeted treatment has been evaluated but has not shown a clear clinical benefit for breast cancer. This review article aims to consider the knowledge of the biological background of EGFR pathways in dissecting clinical studies of EGFR targeted treatment in breast cancer. Areas covered: This review focuses on the role of the EGFR pathway and the investigational drugs that target EGFR for breast cancer. Expert opinion: Recent studies have indicated that EGFR targeted therapy for breast cancer has some promising effects for patients with triple-negative breast cancer, basal-like breast cancer, and inflammatory breast cancer. However, predictive and prognostic biomarkers for EGFR targeted therapy have not been identified. The overexpression or amplification of EGFR itself may not be the true factor of induction of the canonical pathway as an oncogenic driver of breast cancer. Instead, downstream, non-canonical pathways related to EGFR may contribute to some aspects of the biological behavior of breast cancer; therefore, the blockade of the receptor could result in sufficient suppression of downstream pathways to inhibit the aggressive behavior of breast cancer. Mechanistic studies to investigate the dynamic interaction between the EGFR pathway and non-canonical pathways are warranted.

Early clinical development of epidermal growth factor receptor targeted therapy in breast cancer

PubMed Central

Matsuda, Naoko; Lim, Bora; Wang, Xiaoping; Ueno, Naoto T.

2018-01-01

Introduction Epidermal growth factor receptor (EGFR) targeted treatment has been evaluated but has not shown a clear clinical benefit for breast cancer. This review article aims to consider the knowledge of the biological background of EGFR pathways in dissecting clinical studies of EGFR targeted treatment in breast cancer. Areas covered This review focuses on the role of the EGFR pathway and the investigational drugs that target EGFR for breast cancer. Expert opinion Recent studies have indicated that EGFR targeted therapy for breast cancer has some promising effects for patients with triple-negative breast cancer, basal-like breast cancer, and inflammatory breast cancer. However, predictive and prognostic biomarkers for EGFR targeted therapy have not been identified. The overexpression or amplification of EGFR itself may not be the true factor of induction of the canonical pathway as an oncogenic driver of breast cancer. Instead, downstream, non-canonical pathways related to EGFR may contribute to some aspects of the biological behavior of breast cancer; therefore, the blockade of the receptor could result in sufficient suppression of downstream pathways to inhibit the aggressive behavior of breast cancer. Mechanistic studies to investigate the dynamic interaction between the EGFR pathway and non-canonical pathways are warranted. PMID:28271910

Resistance to therapy in estrogen receptor positive and human epidermal growth factor 2 positive breast cancers: progress with latest therapeutic strategies.

PubMed

Lousberg, Laurence; Collignon, Joëlle; Jerusalem, Guy

2016-11-01

In this article, we focus on the subtype of estrogen receptor (ER)-positive, human epidermal growth factor 2 (HER2)-positive breast cancer (BC). Preclinical and clinical data indicate a complex molecular bidirectional crosstalk between the ER and HER2 pathways. This crosstalk probably constitutes one of the key mechanisms of drug resistance in this subclass of BC. Delaying or even reversing drug resistance seems possible by targeting pathways implicated in this crosstalk. High-risk patients currently receive anti-HER2 therapy, chemotherapy and endocrine therapy in the adjuvant setting. In metastatic cases, most patients receive a combination of anti-HER2 therapy and chemotherapy. Only selected patients presenting more indolent disease are candidates for combinations of anti-HER2 therapy and endocrine therapy. However, relative improvements in progression-free survival by chemotherapy-based regimens are usually lower in ER-positive patients than the ER-negative and HER2-positive subgroup. Consequently, new approaches aiming to overcome endocrine therapy resistance by adding targeted therapies to endocrine therapy based regimens are currently explored. In addition, dual blockade of HER2 or the combination of trastuzumab and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOP) inhibitors targeting the downstream pathway are strategies to overcome resistance to trastuzumab. This may lead in the near future to the less frequent use of chemotherapy-based treatment options in ER-positive, HER2-positive BC.

Study and characterization of powder mackerel (Scomberomorus commerson) bone gelatin through hydrolysis of hydrochloric acid

NASA Astrophysics Data System (ADS)

Mardawati, E.; Sugandi, H.; Kayaputri, I. L.; Cahyana, Y.; Wira, D. W.; Pujianto, T.; Kastaman, R.

2018-02-01

Gelatin is one of the most common food additives in the food and beverage industry. Gelatin is generally made of leather or pig bones, causing concerns about the halal and safety of its product. Mackerel fish bone (Scomberomorus commerson) is a waste fish that has not been utilized well and it contains 18.6% of collagen so that it can be made into gelatin. The purpose of this research is to know the relation between HCl concentration with physical and chemical characteristics of gelatin and to know the best HCl concentration for gelatin production. Based on the physical and chemical analysis of gelatin, it is known that the concentration of hydrochloric acid influences the yield, viscosity, gel strength and pH produced. The higher HCl concentration there will be decrease in the pH value, gel strength, viscosity and protein. The yield will rise to the optimum point then decrease with respect to the high HCl concentration. Gelatin with 2% HCl concentration was the best treatment, with pH value 3.83, viscosity 3.65cP, gel strength 190.50 blooms which fulfilled British Standard, yield 10.16%, protein content 43.34%. It has functional group such as amino acids glycine, proline and hydroxyproline and 15 other amino acids, the gelatin group uptake in the region of amide wave numbers A, amides I, II and III, with a gelatin molecular weight of 290.35 g/mol.

Efficient antitumor effect of co-drug-loaded nanoparticles with gelatin hydrogel by local implantation

PubMed Central

Zhang, Hao; Tian, Yong; Zhu, Zhenshu; Xu, Huae; Li, Xiaolin; Zheng, Donghui; Sun, Weihao

2016-01-01

Tetrandrine (Tet) could enhance the antitumor effect of Paclitaxel (Ptx) by increasing intracellular Reactive Oxygen Species (ROS) levels, which leads to the possibility of co-delivery of both drugs for synergistic antitumor effect. In the current study, we reported an efficient, local therapeutic strategy employing effective Tet and Ptx delivery with a nanoparticle-loaded gelatin system. Tet- and Ptx co-loaded mPEG-PCL nanoparticles (P/T-NPs) were encapsulated into the physically cross-linked gelatin hydrogel and then implanted on the tumor site for continuous drug release. The drug-loaded gelatin hydrogel underwent a phase change when the temperature slowly increased. In vitro study showed that Tet/Ptx-loaded PEG-b-PCL nanoparticles encapsulated within a gelatin hydrogel (P/T-NPs-Gelatin) inhibited the growth and invasive ability of BGC-823 cells more effectively than the combination of free drugs or P/T-NPs. In vivo study validated the therapeutic potential of P/T-NPs-Gelatin. P/T-NPs-Gelatin significantly inhibited the activation of p-Akt and the downstream anti-apoptotic Bcl-2 protein and also inducing the activation of pro-apoptotic Bax protein. Moreover, the molecular-modulating effect of P/T-NPs-Gelatin on related proteins varied slightly under the influence of NAC, which was supported by the observations of the tumor volumes and weights. Based on these findings, local implantation of P/T-NPs-Gelatin may be a promising therapeutic strategy for the treatment of gastric cancer. PMID:27226240

Treatment of neural anosmia by topical application of basic fibroblast growth factor-gelatin hydrogel in the nasal cavity: an experimental study in mice.

PubMed

Nota, Jumpei; Takahashi, Hirotaka; Hakuba, Nobuhiro; Hato, Naohito; Gyo, Kiyofumi

2013-04-01

A new treatment of neural anosmia. To investigate the effects of basic fibroblast growth factor (bFGF)-gelatin hydrogel on recovery of neural anosmia in mice. Anosmia was induced by intraperitoneal injection of 3-methylindole, 200 mg/kg. One week later, the animals underwent 1 of the following 3 procedures bilaterally: (1) group A: single-shot intranasal drip infusion of phosphate-buffered saline, (2) group B: single-shot intranasal drip infusion of bFGF, and (3) group C: placement of bFGF-gelatin hydrogel in the nasal cavity. The olfactory function of the animal was evaluated by the odor-detection test (ODT) 2 and 4 weeks later. Following the testing, the animal was killed, the thickness of the olfactory epithelium was measured, and the number of olfactory marker protein (OMP)-positive cells was counted. Research installation. Mice. The placement of bFGF-gelatin hydrogel in the nasal cavity. An ODT, thickness of olfactory epithelium, the number of OMP-positive cells The ODT proved that neural anosmia recovered in group C but not in groups A and B. Histologically, olfactory epithelium became thicker and the number of OMP-positive cells increased in group C, while such functional and histologic recovery was poor in groups A and B. These findings suggested that placement of bFGF-gelatin hydrogel in the nasal cavity was an efficient way to facilitate recovery of neural anosmia. As a gelatin hydrogel degrades slowly in the body, bFGF is gradually released around the site of the lesion; thus, it constantly exerts its effects on neural regeneration.

Epidermal Growth Factor Receptor Tyrosine Kinase: A Potential Target in Treatment of Non-Small-Cell Lung Carcinoma.

PubMed

Prabhu, Venugopal Vinod; Devaraj, Niranjali

2017-01-01

Lung cancer is responsible for 1.6 million deaths. Approximately 80%-85% of lung cancers are of the non-small-cell variety, which includes squamous cell carcinoma, adenocarcinoma, and large-cell carcinoma. Knowing the stage of cancer progression is a requisite for determining which management approach-surgery, chemotherapy, radiotherapy, and/or immunotherapy-is optimal. Targeted therapeutic approaches with antiangiogenic monoclonal antibodies or tyrosine kinase inhibitors are one option if tumors harbor oncogene mutations. Another, newer approach is directed against cancer-specific molecules and signaling pathways and thus has more limited nonspecific toxicities. This approach targets the epidermal growth factor receptor (EGFR, HER-1/ErbB1), a receptor tyrosine kinase of the ErbB family, which consists of four closely related receptors: HER-1/ErbB1, HER-2/neu/ErbB2, HER-3/ErbB3, and HER-4/ErbB4. Because EGFR is expressed at high levels on the surface of some cancer cells, it has been recognized as an effective anticancer target. EGFR-targeted therapies include monoclonal antibodies (mAbs) and small-molecule tyrosine kinase inhibitors. Tyrosine kinases are an especially important target because they play an important role in the modulation of growth factor signaling. This review highlights various classes of synthetically derived molecules that have been reported in the last few years as potential EGFR-TK inhibitors (TKIs) and their targeted therapies in NSCLC, along with effective strategies for overcoming EGFR-TKI resistance and efforts to develop a novel potent EGFR-TKI as an efficient target of NSCLC treatment in the foreseeable future.

Host target modification as a strategy to counter pathogen hijacking of the jasmonate hormone receptor

DOE PAGES

Zhang, Li; Yao, Jian; Withers, John; ...

2015-11-02

In the past decade, characterization of the host targets of pathogen virulence factors took a center stage in the study of pathogenesis and disease susceptibility in plants and humans. However, the impressive knowledge of host targets has not been broadly exploited to inhibit pathogen infection. In this paper, we show that host target modification could be a promising new approach to “protect” the disease-vulnerable components of plants. In particular, recent studies have identified the plant hormone jasmonate (JA) receptor as one of the common targets of virulence factors from highly evolved biotrophic/hemibiotrophic pathogens. Strains of the bacterial pathogen Pseudomonas syringae,more » for example, produce proteinaceous effectors, as well as a JA-mimicking toxin, coronatine (COR), to activate JA signaling as a mechanism to promote disease susceptibility. Guided by the crystal structure of the JA receptor and evolutionary clues, we succeeded in modifying the JA receptor to allow for sufficient endogenous JA signaling but greatly reduced sensitivity to COR. Transgenic Arabidopsis expressing this modified receptor not only are fertile and maintain a high level of insect defense, but also gain the ability to resist COR-producing pathogens Pseudomonas syringae pv. tomato and P. syringae pv. maculicola. Finally, our results provide a proof-of-concept demonstration that host target modification can be a promising new approach to prevent the virulence action of highly evolved pathogens.« less

Nanoparticle-based strategy for personalized B-cell lymphoma therapy

PubMed Central

Martucci, Nicola M; Migliaccio, Nunzia; Ruggiero, Immacolata; Albano, Francesco; Calì, Gaetano; Romano, Simona; Terracciano, Monica; Rea, Ilaria; Arcari, Paolo; Lamberti, Annalisa

2016-01-01

B-cell lymphoma is associated with incomplete response to treatment, and the development of effective strategies targeting this disease remains challenging. A new personalized B-cell lymphoma therapy, based on a site-specific receptor-mediated drug delivery system, was developed in this study. Specifically, natural silica-based nanoparticles (diatomite) were modified to actively target the antiapoptotic factor B-cell lymphoma/leukemia 2 (Bcl2) with small interfering RNA (siRNA). An idiotype-specific peptide (Id-peptide) specifically recognized by the hypervariable region of surface immunoglobulin B-cell receptor was exploited as a homing device to ensure specific targeting of lymphoma cells. Specific nanoparticle uptake, driven by the Id-peptide, was evaluated by flow cytometry and confocal microscopy and was increased by approximately threefold in target cells compared with nonspecific myeloma cells and when a random control peptide was used instead of Id-peptide. The specific internalization efficiency was increased by fourfold when siRNA was also added to the modified nanoparticles. The modified diatomite particles were not cytotoxic and their effectiveness in downregulation of gene expression was explored using siRNA targeting Bcl2 and evaluated by quantitative real-time polymerase chain reaction and Western blot analyses. The resulting gene silencing observed is of significant biological importance and opens new possibilities for the personalized treatment of lymphomas. PMID:27895482

Effectiveness of a new gelatin sealant system for dural closure.

PubMed

Kawai, Hisashi; Nakagawa, Ichiro; Nishimura, Fumihiko; Motoyama, Yasushi; Park, Young-Su; Nakamura, Mitsutoshi; Nakase, Hiroyuki; Suzuki, Shuko; Ikada, Yoshito

2014-10-01

Watertight dural closure is imperative after neurosurgical procedures because inadequately treated leakage of cerebrospinal fluid (CSF) can have serious consequences. In this study, the authors test the use of a new gelatin glue as a dural sealant in in vitro and in vivo canine models of transdural CSF leakage. The in vitro model was sutured semicircles of canine dura mater and artificial dural substitute. The sutures were sealed with gelatin glue (n  =  20), fibrin glue (n  =  20), or a polyethylene glycol (PEG)-based hydrogel sealant (n  =  20). Each sample was set in a device to measure water pressure, and pressure was increased until leakage occurred. Bonding strength was subjectively evaluated. The in vivo model was dogs who underwent dural excision and received either no sealant (control group; n  =  5) or gelatin glue sealant (n  =  5) before dural closure. Twenty-eight days post-surgery, the maximum intracranial pressure was measured at the cisterna magna using Valsalva maneuver and tissue adhesion was evaluated. The water pressure at which leakage occurred in the in vitro model was higher with gelatin glue (76·5 ± 39·8 mmHg) than with fibrin glue (38·3 ± 27·4 mmHg, P < 0·001) or the PEG-based hydrogel sealant (46·3 ± 20·9 mmHg, P  =  0·007). Bonding strength was higher for the gelatin glue than fibrin glue (P < 0·001) or PEG-based hydrogel sealant (P  =  0·001). The maximum intracranial pressure in the in vivo model was higher for the gelatin glue group (59·0 ± 2·2 mmHg) than the control group (13·8 ± 4·0 mmHg, P < 0·001). Tissue adhesion was lower for the gelatin glue group than the control group (P  =  0·005). The new gelatin glue provides an effective watertight closure when used as an adjunct to sutured dural repair.

2-hydroxyethyl metahcrylate/gelatin based superporous hydrogels for tissue regeneration

NASA Astrophysics Data System (ADS)

Tomić, Simonida Lj.; Babić, Marija M.; Vuković, Jovana S.; Perišić, Marija D.; Filipović, Vuk V.; Davidović, Sladjana Z.; Filipović, Jovanka M.

2016-05-01

In this study, superporous hydrogels were synthesized by free radical polymerization of 2-hydroxyethyl methacrylate without and in the presence of gelatin. Highly porous hydrogel structures were obtained by two different techniques: using a gas blowing agent, sodium bicarbonate, and a cryogenic treatment followed by freeze-drying. After the gel synthesis, gelatin molecules were covalently immobilised onto PHEMA via glytaraldehyde activation. All samples were characterized for morphological, mechanical, swelling and antibacterial properties. The results obtained show that samples with gelatin show better properties in comparison with PHEMA samples, which make these materials highly attractive for developing hydrogel scaffolds for tissue regeneration.

Modification of cytokine-induced killer cells with chimeric antigen receptors (CARs) enhances antitumor immunity to epidermal growth factor receptor (EGFR)-positive malignancies.

PubMed

Ren, Xuequn; Ma, Wanli; Lu, Hong; Yuan, Lei; An, Lei; Wang, Xicai; Cheng, Guanchang; Zuo, Shuguang

2015-12-01

Epidermal growth factor receptor (EGFR, ErbB1, Her-1) is a cell surface molecule overexpressing in a variety of human malignancies and, thus, is an excellent target for immunotherapy. Immunotherapy targeting EGFR-overexpressing malignancies using genetically modified immune effector cells is a novel and promising approach. In the present study, we have developed an adoptive cellular immunotherapy strategy based on the chimeric antigen receptor (CAR)-modified cytokine-induced killer (CAR-CIK) cells specific for the tumor cells expressing EGFR. To generate CAR-CIK cells, a lentiviral vector coding the EGFR-specific CAR was constructed and transduced into the CIK cells. The CAR-CIK cells showed significantly enhanced cytotoxicity and increased production of cytokines IFN-γ and IL-2 when co-cultured with EGFR-positive cancer cells. In tumor xenografts, adoptive immunotherapy of CAR-CIK cells could inhibit tumor growth and prolong the survival of EGFR-overexpressing human tumor xenografts. Moreover, tumor growth inhibition and prolonged survival in mice with EGFR(+) human cancer were associated with the increased persistence of CAR-CIK cells in vivo. Our study indicates that modification with EGFR-specific CAR strongly enhances the antitumor activity of the CIK cells against EGFR-positive malignancies.

The role of STATs in lung carcinogenesis: an emerging target for novel therapeutics.

PubMed

Karamouzis, Michalis V; Konstantinopoulos, Panagiotis A; Papavassiliou, Athanasios G

2007-05-01

The signal transducer and activator of transcription (STAT) proteins are a family of latent cytoplasmic transcription factors, which form dimers when activated by cytokine receptors, tyrosine kinase growth factor receptors as well as non-receptor tyrosine kinases. Dimeric STATs translocate to the nucleus, where they bind to specific DNA-response elements in the promoters of target genes, thereby inducing unique gene expression programs often in association with other transcription regulatory proteins. The functional consequence of different STAT proteins activation varies, as their target genes play diverse roles in normal cellular/tissue functions, including growth, apoptosis, differentiation and angiogenesis. Certain activated STATs have been implicated in human carcinogenesis, albeit only few studies have focused into their role in lung tumours. Converging evidence unravels their molecular interplays and complex multipartite regulation, rendering some of them appealing targets for lung cancer treatment with new developing strategies.

Anticancer molecules targeting fibroblast growth factor receptors.

PubMed

Liang, Guang; Liu, Zhiguo; Wu, Jianzhang; Cai, Yuepiao; Li, Xiaokun

2012-10-01

The fibroblast growth factor receptor (FGFR) family includes four highly conserved receptor tyrosine kinases: FGFR1-4. Upon ligand binding, FGFRs activate an array of downstream signaling pathways, such as the mitogen activated protein kinase (MAPK) and the phosphoinositide-3-kinase (PI3K)/Akt pathways. These FGFR cascades play crucial roles in tumor cell proliferation, angiogenesis, migration, and survival. The combination of knockdown studies and pharmaceutical inhibition in preclinical models demonstrates that FGFRs are attractive targets for therapeutic intervention in cancer. Multiple FGFR inhibitors with various structural skeletons have been designed, synthesized, and evaluated. Reviews on FGFRs have recently focused on FGFR signaling, pathophysiology, and functions in cancer or other diseases. In this article, we review recent advances in structure-activity relationships (SAR) of FGFR inhibitors, as well as the FGFR-targeting drug design strategies currently employed in targeting deregulated FGFRs by antibodies and small molecule inhibitors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Graphene oxide decorated electrospun gelatin nanofibers: Fabrication, properties and applications.

PubMed

Jalaja, K; Sreehari, V S; Kumar, P R Anil; Nirmala, R James

2016-07-01

Gelatin nanofiber fabricated by electrospinning process is found to mimic the complex structural and functional properties of natural extracellular matrix for tissue regeneration. In order to improve the physico-chemical and biological properties of the nanofibers, graphene oxide is incorporated in the gelatin to form graphene oxide decorated gelatin nanofibers. The current research effort is focussed on the fabrication and evaluation of physico-chemical and biological properties of graphene oxide-gelatin composite nanofibers. The presence of graphene oxide in the nanofibers was established by transmission electron microscopy (TEM). We report the effect of incorporation of graphene oxide on the mechanical, thermal and biological performance of the gelatin nanofibers. The tensile strength of gelatin nanofibers was increased from 8.29±0.53MPa to 21±2.03MPa after the incorporation of GO. In order to improve the water resistance of nanofibers, natural based cross-linking agent, namely, dextran aldehyde was employed. The cross-linked composite nanofibers showed further increase in the tensile strength up to 56.4±2.03MPa. Graphene oxide incorporated gelatin nanofibers are evaluated for bacterial activity against gram positive (Staphylococcus aureus) and gram negative (Escherichia coli) bacteria and cyto compatibility using mouse fibroblast cells (L-929 cells). The results indicate that the graphene oxide incorporated gelatin nanofibers do not prevent bacterial growth, nevertheless support the L-929 cell adhesion and proliferation. Copyright © 2016 Elsevier B.V. All rights reserved.

Fabrication of a three-dimensional β-tricalcium-phosphate/gelatin containing chitosan-based nanoparticles for sustained release of bone morphogenetic protein-2: Implication for bone tissue engineering.

PubMed

Bastami, Farshid; Paknejad, Zahrasadat; Jafari, Maissa; Salehi, Majid; Rezai Rad, Maryam; Khojasteh, Arash

2017-03-01

Fabrication of an ideal scaffold having proper composition, physical structure and able to have sustained release of growth factors still is challenging for bone tissue engineering. Current study aimed to design an appropriate three-dimensional (3-D) scaffold with suitable physical characteristics, including proper compressive strength, degradation rate, porosity, and able to sustained release of bone morphogenetic protein-2 (BMP2), for bone tissue engineering. A highly porous 3-D β-tricalcium phosphate (β-TCP) scaffolds, inside of which two perpendicular canals were created, was fabricated using foam-casting technique. Then, scaffolds were coated with gelatin layer. Next, BMP2-loaded chitosan (CS) nanoparticles were dispersed into collagen hydrogel and filled into the scaffold canals. Physical characteristics of fabricated constructs were evaluated. Moreover, the capability of given construct for bone regeneration has been evaluated in vitro in interaction with human buccal fat pad-derived stem cells (hBFPSCs). The results showed that gelatin-coated TCP scaffold with rhBMP2 delivery system not only could act as a mechanically and biologically compatible framework, but also act as an osteoinductive graft by sustained delivering of rhBMP2 in a therapeutic window for differentiation of hBFPSCs towards the osteoblast lineage. The proposed scaffold model can be suggested for delivering of cells and other growth factors such as vascular endothelial growth factor (VEGF), alone or in combination, for future investigations. Copyright © 2016 Elsevier B.V. All rights reserved.

Adnectin-Based Design of Chimeric Antigen Receptor for T Cell Engineering.

PubMed

Han, Xiaolu; Cinay, Gunce E; Zhao, Yifan; Guo, Yunfei; Zhang, Xiaoyang; Wang, Pin

2017-11-01

Although chimeric antigen receptor (CAR)-engineered T cell therapy has achieved encouraging clinical trial results for treating hematological cancers, further optimization can likely expand this therapeutic success to more patients and other cancer types. Most CAR constructs used in clinical trials incorporate single chain variable fragment (scFv) as the extracellular antigen recognition domain. The immunogenicity of nonhuman scFv could cause host rejection against CAR T cells and compromise their persistence and efficacy. The limited availability of scFvs and slow discovery of new monoclonal antibodies also limit the development of novel CAR constructs. Adnectin, a class of affinity molecules derived from the tenth type III domain of human fibronectin, can be an alternative to scFv as an antigen-binding moiety in the design of CAR molecules. We constructed adnectin-based CARs targeting epithelial growth factor receptor (EGFR) and found that compared to scFv-based CAR, T cells engineered with adnectin-based CARs exhibited equivalent cell-killing activity against target H292 lung cancer cells in vitro and had comparable antitumor efficacy in xenograft tumor-bearing mice in vivo. In addition, with optimal affinity tuning, adnectin-based CAR showed higher selectivity on target cells with high EGFR expression than on those with low expression. This new design of adnectin CARs can potentially facilitate the development of T cell immunotherapy for cancer and other diseases. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

An NMR relaxometry and gravimetric study of gelatin-free aqueous polyacrylamide dosimeters

NASA Astrophysics Data System (ADS)

Babic, Steven; Schreiner, L. John

2006-09-01

In conformal radiation therapy, a high dose of radiation is given to a target volume to increase the probability of cure, and care is taken to minimize the dose to surrounding healthy tissue. The techniques used to achieve this are very complicated and the precise verification of the resulting three-dimensional (3D) dose distribution is required. Polyacrylamide gelatin (PAG) dosimeters with magnetic resonance imaging and optical computed tomography scanning provide the required 3D dosimetry with high spatial resolution. Many basic studies have characterized these chemical dosimeters that polymerize under irradiation. However, the investigation of the fundamental properties of the radiation-induced polymerization in PAG dosimeters is complicated by the presence of the background gelatin matrix. In this work, a gelatin-free model system for the study of the basic radiation-induced polymerization in PAG dosimeters has been developed. Experiments were performed on gelatin-free dosimeters, named aqueous polyacrylamide (APA) dosimeters, containing equal amounts of acrylamide and N,N'-methylene-bisacrylamide. The APA dosimeters were prepared with four different total monomer concentrations (2, 4, 6 and 8% by weight). Nuclear magnetic resonance (NMR) spin-spin and spin-lattice proton relaxation measurements at 20 MHz, and gravimetric analyses performed on all four dosimeters, show a continuous degree of polymerization over the dose range of 0-25 Gy. The developed NMR model explains the relationship observed between the relaxation data and the amount of crosslinked polymer formed at each dose. This model can be extended with gelatin relaxation data to provide a fundamental understanding of radiation-induced polymerization in the conventional PAG dosimeters.

An NMR relaxometry and gravimetric study of gelatin-free aqueous polyacrylamide dosimeters.

PubMed

Babic, Steven; Schreiner, L John

2006-09-07

In conformal radiation therapy, a high dose of radiation is given to a target volume to increase the probability of cure, and care is taken to minimize the dose to surrounding healthy tissue. The techniques used to achieve this are very complicated and the precise verification of the resulting three-dimensional (3D) dose distribution is required. Polyacrylamide gelatin (PAG) dosimeters with magnetic resonance imaging and optical computed tomography scanning provide the required 3D dosimetry with high spatial resolution. Many basic studies have characterized these chemical dosimeters that polymerize under irradiation. However, the investigation of the fundamental properties of the radiation-induced polymerization in PAG dosimeters is complicated by the presence of the background gelatin matrix. In this work, a gelatin-free model system for the study of the basic radiation-induced polymerization in PAG dosimeters has been developed. Experiments were performed on gelatin-free dosimeters, named aqueous polyacrylamide (APA) dosimeters, containing equal amounts of acrylamide and N,N'-methylene-bisacrylamide. The APA dosimeters were prepared with four different total monomer concentrations (2, 4, 6 and 8% by weight). Nuclear magnetic resonance (NMR) spin-spin and spin-lattice proton relaxation measurements at 20 MHz, and gravimetric analyses performed on all four dosimeters, show a continuous degree of polymerization over the dose range of 0-25 Gy. The developed NMR model explains the relationship observed between the relaxation data and the amount of crosslinked polymer formed at each dose. This model can be extended with gelatin relaxation data to provide a fundamental understanding of radiation-induced polymerization in the conventional PAG dosimeters.

Activation of BAD by therapeutic inhibition of epidermal growth factor receptor and transactivation by insulin-like growth factor receptor.

PubMed

Gilmore, Andrew P; Valentijn, Anthony J; Wang, Pengbo; Ranger, Ann M; Bundred, Nigel; O'Hare, Michael J; Wakeling, Alan; Korsmeyer, Stanley J; Streuli, Charles H

2002-08-02

Novel cancer chemotherapeutics are required to induce apoptosis by activating pro-apoptotic proteins. Both epidermal growth factor (EGF) and insulin-like growth factor (IGF) provide potent survival stimuli in many epithelia, and activation of their receptors is commonly observed in solid human tumors. Here we demonstrate that blockade of the EGF receptor by a new drug in phase III clinical trails for cancer, ZD1839, potently induces apoptosis in mammary epithelial cell lines and primary cultures, as well as in a primary pleural effusion from a breast cancer patient. We identified the mechanism of apoptosis induction by ZD1839. We showed that it prevents cell survival by activating the pro-apoptotic protein BAD. Moreover, we demonstrate that IGF transactivates the EGF receptor and that ZD1839 blocks IGF-mediated phosphorylation of MAPK and BAD. Many cancer therapies kill tumor cells by inducing apoptosis as a consequence of targeting DNA; however, the threshold at which apoptosis can be triggered through DNA damage is often different from that in normal cells. Our results indicate that by targeting a growth factor-mediated survival signaling pathway, BAD phosphorylation can be manipulated therapeutically to induce apoptosis.

Emodin suppresses maintenance of stemness by augmenting proteosomal degradation of epidermal growth factor receptor/epidermal growth factor receptor variant III in glioma stem cells.

PubMed

Kim, Jeongyub; Lee, Jong-Seon; Jung, Jieun; Lim, Inhye; Lee, Ji-Yun; Park, Myung-Jin

2015-02-01

There is a growing body of evidence that small subpopulations of cells with stem cell-like characteristics within most solid tumors are responsible for the malignancy of aggressive cancer cells and that targeting these cells might be a good therapeutic strategy to reduce the risk of tumor relapse after therapy. Here, we examined the effects of emodin (1,3,8-trihydroxy-6-methylanthraquinone), an active component of the root and rhizome of Rheum palmatum that has several biological activities, including antitumor effects, on primary cultured glioma stem cells (GSCs). Emodin inhibited the self-renewal activity of GSCs in vitro as evidenced by neurosphere formation, limiting dilution, and soft agar clonogenic assays. Emodin inhibited the maintenance of stemness by suppressing the expression of Notch intracellular domain, nonphosphorylated β-catenin, and phosphorylated STAT3 proteins. In addition, treatment with emodin partially induced apoptosis, reduced cell invasiveness, and sensitized GSCs to ionizing radiation. Intriguingly, emodin induced proteosomal degradation of epidermal growth factor receptor (EGFR)/EGFR variant III (EGFRvIII) by interfering with the association of EGFR/EGFRvIII with heat shock protein 90, resulting in the suppression of stemness pathways. Based on these data, we propose that emodin could be considered as a potent therapeutic adjuvant that targets GSCs.

Hepatic macrophage complement receptor clearance function following injury.

PubMed

Cuddy, B G; Loegering, D J; Blumenstock, F A; Shah, D M

1986-03-01

Previous work has demonstrated that in vivo hepatic macrophage complement receptor clearance function is depressed following thermal injury. The present study was carried out to determine if complement receptor function depression is associated with other states of depressed host defense. Hepatic complement receptor clearance function was determined from the hepatic uptake of rat erythrocytes coated with antierythrocyte IgM (EIgM) in rats. Receptor function was determined following cannulation of a carotid artery, laparotomy plus enterotomy, hemorrhagic shock, trauma, thermal injury, acute bacteremia, acute endotoxemia, and injection of erythrocyte stroma, gelatinized lipid emulsion, or colloidal carbon. Hepatic uptake of EIgM was depressed following each of these experimental interventions except arterial cannulation. This effect was shown not to be due to a decrease in hepatic blood flow or depletion of complement and was therefore due to a depression in hepatic macrophage complement receptor clearance function. Thus, impairment of hepatic macrophage complement receptor function is associated with several states of depressed host defense.

Comparative study of chitosan and chitosan-gelatin scaffold for tissue engineering

NASA Astrophysics Data System (ADS)

Kumar, Pawan; Dehiya, Brijnandan S.; Sindhu, Anil

2017-12-01

A number of orthopedic disorders and bone defect issues are solved by scaffold-based therapy in tissue engineering. The biocompatibility of chitosan (polysaccharide) and its similarity with glycosaminoglycan makes it a bone-grafting material. The current work focus on the synthesis of chitosan and chitosan-gelatin scaffold for hard tissue engineering. The chitosan and chitosan-gelatin scaffold have shown improved specific surface area, density, porosity, mechanical properties, biodegradability and absorption. These scaffolds can lead to the development or artificial fabrication of hard tissue alternates. The porous scaffold samples were prepared by freeze-drying method. The microstructure, mechanical and degradable properties of chitosan and chitosan-gelatin scaffolds were analyzed and results revealed that the scaffolds prepared from chitosan-gelatin can be utilized as a useful matrix for tissue engineering.

Update on peripheral mechanisms of pain: beyond prostaglandins and cytokines

PubMed Central

2011-01-01

The peripheral nociceptor is an important target of pain therapy because many pathological conditions such as inflammation excite and sensitize peripheral nociceptors. Numerous ion channels and receptors for inflammatory mediators were identified in nociceptors that are involved in neuronal excitation and sensitization, and new targets, beyond prostaglandins and cytokines, emerged for pain therapy. This review addresses mechanisms of nociception and focuses on molecules that are currently favored as new targets in drug development or that are already targeted by new compounds at the stage of clinical trials - namely the transient receptor potential V1 receptor, nerve growth factor, and voltage-gated sodium channels - or both. PMID:21542894

A Preliminary Evaluation of Lyophilized Gelatin Sponges, Enhanced with Platelet-Rich Plasma, Hydroxyapatite and Chitin Whiskers for Bone Regeneration

PubMed Central

Rodriguez, Isaac A.; Sell, Scott A.; McCool, Jennifer M.; Saxena, Gunjan; Spence, Andrew J.; Bowlin, Gary L.

2013-01-01

The purpose of this study was to perform a number of preliminary in vitro evaluations on an array of modified gelatin gel sponge scaffolds for use in a bone graft application. The gelatin gels were modified through the addition of a number of components which each possess unique properties conducive to the creation and regeneration of bone: a preparation rich in growth factors (PRGF, a bioactive, lyophilized form of platelet-rich plasma), hydroxyapatite, and chitin whiskers. Platelet-rich plasma therapy is an emerging practice that has proven effective in a number of clinical applications, including enhancing bone repair through improved deposition of new bony matrix and angiogenesis. As such, the inclusion of PRGF in our gelatin scaffolds was intended to significantly enhance scaffold bioactivity, while the addition of hydroxyapatite and chitin whiskers were anticipated to increase scaffold strength. Additionally, the gelatin sponges, which readily dissolve in aqueous solutions, were subjected to 1-Ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride (EDC) cross-linking, either during or post-gelation, to control their rate of degradation. Scaffolds were evaluated in vitro with respect to compressive strength, mass loss/degradation, protein release, and cellular interaction, with results demonstrating the potential of the gelatin gel sponge scaffold for use in the regeneration of bone. PMID:24709699

Skin problems and EGFR-tyrosine kinase inhibitor.

PubMed

Kozuki, Toshiyuki

2016-04-01

Epidermal growth factor receptor inhibition is a good target for the treatment of lung, colon, pancreatic and head and neck cancers. Epidermal growth factor receptor-tyrosine kinase inhibitor was first approved for the treatment of advanced lung cancer in 2002. Epidermal growth factor receptor-tyrosine kinase inhibitor plays an essential role in the treatment of cancer, especially for patients harbouring epidermal growth factor receptor activating mutation. Hence, skin toxicity is the most concerning issue for the epidermal growth factor receptor-tyrosine kinase inhibitor treatment. Skin toxicity is bothersome and sometimes affects the quality of life and treatment compliance. Thus, it is important for physicians to understand the background and how to manage epidermal growth factor receptor-tyrosine kinase inhibitor-associated skin toxicity. Here, the author reviewed the mechanism and upfront preventive and reactive treatments for epidermal growth factor receptor inhibitor-associated skin toxicities. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Structural Overview of the Nuclear Receptor Superfamily: Insights into Physiology and Therapeutics

PubMed Central

Huang, Pengxiang; Chandra, Vikas; Rastinejad, Fraydoon

2013-01-01

As ligand-regulated transcription factors, the nuclear hormone receptors are nearly ideal drug targets, with internal pockets that bind to hydrophobic, drug-like molecules and well-characterized ligand-induced conformational changes that recruit transcriptional coregulators to promoter elements. Yet, due to the multitude of genes under the control of a single receptor, the major challenge has been the identification of ligands with gene-selective actions, impacting disease outcomes through a narrow subset of target genes and not across their entire gene-regulatory repertoire. Here, we summarize the concepts and work to date underlying the development of steroidal and nonsteroidal receptor ligands, including the use of crystal structures, high-throughput screens, and rational design approaches for finding useful therapeutic molecules. Difficulties in finding selective receptor modulators require a more complete understanding of receptor interdomain communications, posttranslational modifications, and receptor-protein interactions that could be exploited for target gene selectivity. PMID:20148675

An innovative three-dimensional gelatin foam culture system for improved study of glioblastoma stem cell behavior.

PubMed

Yang, Meng-Yin; Chiao, Ming-Tsang; Lee, Hsu-Tung; Chen, Chien-Min; Yang, Yi-Chin; Shen, Chiung-Chyi; Ma, Hsin-I

2015-04-01

Three-dimensional (3-D) tissue engineered constructs provide a platform for examining how the local extracellular matrix contributes to the malignancy of various cancers, including human glioblastoma multiforme. Here, we describe a simple and innovative 3-D culture environment and assess its potential for use with glioblastoma stem cells (GSCs) to examine the diversification inside the cell mass in the 3-D culture system. The dissociated human GSCs were cultured using gelatin foam. These cells were subsequently identified by immunohistochemical staining, reverse transcriptase-polymerase chain reaction, and Western blot assay. We demonstrate that the gelatin foam provides a suitable microenvironment, as a 3-D culture system, for GSCs to maintain their stemness. The gelatin foam culture system contributes a simplified assessment of cell blocks for immunohistochemistry assay. We show that the significant transcription activity of hypoxia and the protein expression of inflammatory responses are detected at the inside of the cell mass in vitro, while robust expression of PROM1/CD133 and hypoxia-induced factor-1 alpha are detected at the xenografted tumor in vivo. We also examine the common clinical trials under this culture platform and characterized a significant difference of drug resistance. The 3-D gelatin foam culture system can provide a more realistic microenvironment through which to study the in vivo behavior of GSCs to evaluate the role that biophysical factors play in the hypoxia, inflammatory responses and subsequent drug resistance. © 2014 Wiley Periodicals, Inc.

Molecular neuro-oncology and development of targeted therapeutic strategies for brain tumors. Part 1: Growth factor and Ras signaling pathways.

PubMed

Newton, Herbert B

2003-10-01

Brain tumors are a diverse group of malignancies that remain refractory to conventional treatment approaches, including radiotherapy and cytotoxic chemotherapy. Molecular neuro-oncology has now begun to clarify the transformed phenotype of brain tumors and identify oncogenic pathways that may be amenable to targeted therapy. Growth factor signaling pathways are often upregulated in brain tumors and may contribute to oncogenesis through autocrine and paracrine mechanisms. Excessive growth factor receptor stimulation can also lead to overactivity of the Ras signaling pathway, which is frequently aberrant in brain tumors. Receptor tyrosine kinase inhibitors, antireceptor monoclonal antibodies and antisense oligonucleotides are targeted approaches under investigation as methods to regulate aberrant growth factor signaling pathways in brain tumors. Several receptor tyrosine kinase inhibitors, including imatinib mesylate (Gleevec), gefitinib (Iressa) and erlotinib (Tarceva), have entered clinical trials for high-grade glioma patients. Farnesyl transferase inhibitors, such as tipifarnib (Zarnestra), which impair processing of proRas and inhibit the Ras signaling pathway, have also entered clinical trials for patients with malignant gliomas. Further development of targeted therapies and evaluation of these new agents in clinical trials will be needed to improve survival and quality of life of patients with brain tumors.

Electrospun Blends of Gelatin and Gelatin-dendrimer Conjugates as a Wound Dressing and Drug Delivery Platform

PubMed Central

Dongargaonkar, Alpana A.; Bowlin, Gary L.; Yang, Hu

2013-01-01

In this work, we report a new nanofiber construct based on electrospun blends of gelatin and gelatin-dendrimer conjugates. Highly branched star-shaped polyamidoamine (PAMAM) dendrimer G3.5 was covalently conjugated to gelatin via EDC/NHS chemistry. Blends of gelatin and gelatin-dendrimer conjugates mixed with various loading levels of silver acetate (0, 0.83, 1.65, and 3.30% w/w) were successfully electrospun into nanofiber constructs (NCs). The NCs were further converted into semi-interpenetrating networks (sIPNs) with photoreactive polyethylene glycol diacrylate (Mn=575 gmol-1) (PEG DA575). They were characterized in terms of fiber morphology, diameter, pore size, permeability, degradation, and mechanical properties. The resulting sIPN NCs retained nanofiber morphology, possessed similar fiber diameters to counterpart NCs, and gained improved structural stability. The sIPN NCs also showed good swelling capacity owing to porous structures and were permeable to aqueous solutions. Silvercontaining sIPN NCs allowed sustained silver release and showed antimicrobial activity against two common types of pathogens—Staphylococcus aureus and Pseudomonas aeruginosa. Incorporation of dendrimers into the gelatin nanofibers through covalent conjugation not only expands drug loading capacity of nanofiber constructs but provides tremendous flexibility for developing multifunctional electrospun dressing materials. PMID:24127747

Effects of alga polysaccharide capsule shells on in-vivo bioavailability and disintegration

NASA Astrophysics Data System (ADS)

Li, Ting; Guo, Shuju; Ma, Lin; Yuan, Yi; Han, Lijun

2012-01-01

Gelatin has been used in hard capsule shells for more than a century, and some shortcomings have appeared, such as high moisture content and risk of transmitting diseases of animal origin to people. Based on available studies regarding gelatin and vegetable shells, we developed a new type of algal polysaccharide capsule (APPC) shells. To test whether our products can replace commercial gelatin shells, we measured in-vivo plasma concentration of 12 selected volunteers with a model drug, ibuprofen, using high performance liquid chromatography (HPLC), by calculating the relative bioavailability of APPC and Qualicaps® referenced to gelatin capsules and assessing bioequivalence of the three types of shells, and calculated pharmacokinetic parameters with the software DAS 2.0 (China). The results show that APPC shells possess bioequivalence with Qualicaps® and gelatin shells. Moreover, the disintegration behavior of four types of shells (APPC, Vegcaps®, Qualicaps® and gelatin shells) with the content of lactose and radioactive element (99mTc) was observed via gamma-scintigraphic images. The bioavailability and gamma-scintigraphic studies showed that APPC was not statistically different from other vegetable and gelatin capsule shells with respect to in-vivo behavior. Hence, it can be concluded that APPCs are exchangeable with other vegetable and gelatin shells.

Guanylate-binding protein-1 is a potential new therapeutic target for triple-negative breast cancer.

PubMed

Quintero, Melissa; Adamoski, Douglas; Reis, Larissa Menezes Dos; Ascenção, Carolline Fernanda Rodrigues; Oliveira, Krishina Ratna Sousa de; Gonçalves, Kaliandra de Almeida; Dias, Marília Meira; Carazzolle, Marcelo Falsarella; Dias, Sandra Martha Gomes

2017-11-07

Triple-negative breast cancer (TNBC) is characterized by a lack of estrogen and progesterone receptor expression (ESR and PGR, respectively) and an absence of human epithelial growth factor receptor (ERBB2) amplification. Approximately 15-20% of breast malignancies are TNBC. Patients with TNBC often have an unfavorable prognosis. In addition, TNBC represents an important clinical challenge since it does not respond to hormone therapy. In this work, we integrated high-throughput mRNA sequencing (RNA-Seq) data from normal and tumor tissues (obtained from The Cancer Genome Atlas, TCGA) and cell lines obtained through in-house sequencing or available from the Gene Expression Omnibus (GEO) to generate a unified list of differentially expressed (DE) genes. Methylome and proteomic data were integrated to our analysis to give further support to our findings. Genes that were overexpressed in TNBC were then curated to retain new potentially druggable targets based on in silico analysis. Knocking-down was used to assess gene importance for TNBC cell proliferation. Our pipeline analysis generated a list of 243 potential new targets for treating TNBC. We finally demonstrated that knock-down of Guanylate-Binding Protein 1 (GBP1 ), one of the candidate genes, selectively affected the growth of TNBC cell lines. Moreover, we showed that GBP1 expression was controlled by epidermal growth factor receptor (EGFR) in breast cancer cell lines. We propose that GBP1 is a new potential druggable therapeutic target for treating TNBC with enhanced EGFR expression.

Drug delivery with microsecond laser pulses into gelatin.

PubMed

Shangguan, H; Casperson, L W; Shearin, A; Gregory, K W; Prahl, S A

1996-07-01

Photo acoustic drug delivery is a technique for localized drug delivery by laser-induced hydrodynamic pressure following cavitation bubble expansion and collapse. Photoacoustic drug delivery was investigated on gelatin-based thrombus models with planar and cylindrical geometries by use of one microsecond laser pulses. Solutions of a hydrophobic dye in mineral oil permitted monitoring of delivered colored oil into clear gelatin-based thrombus models. Cavitation bubble development and photoacoustic drug delivery were visualized with flash photography. This study demonstrated that cavitation is the governing mechanism for photoacoustic drug delivery, and the deepest penetration of colored oil in gels followed the bubble collapse. Spatial distribution measurements revealed that colored oil could be driven a few millimeters into the gels in both axial and radial directions, and the penetration was less than 500 µm when the gelatin structure was not fractured.

Inadvertent prescription of gelatin-containing oral medication: its acceptability to patients.

PubMed

Vissamsetti, Bharat; Payne, Mark; Payne, Stephen

2012-09-01

When prescribing, doctors usually only consider the 'active' component of any drug's formulation ignoring the majority of the agents which make up the bulk of the tablet or capsule, collectively known as excipients. Many urological drugs contain the excipient gelatin which is, universally, of animal origin; this may conflict with the dietetic ideals of patients. A questionnaire-based study, undertaken between January and June 2010 in a mixed ethnicity inner-city population presenting with urological symptoms, asked which patients preferred not to ingest animal-based products, who would ask about the content of their prescribed treatment and who would refuse to take that medication if alternatives were available. Ultimately, the authors sought to find out how many patients had been inadvertently prescribed gelatin-containing oral medications and to suggest ways in which prescriptions might be more congruous with an individual patient's dietetic wishes. This study demonstrated that 43.2% of the study population would prefer not to take animal product-containing medication even if no alternative were available. 51% of men with lower urinary tract symptoms were also found to have inadvertently been prescribed gelatin-containing products against their preferred dietary restriction. Education of healthcare professionals about excipients and getting them to ask about a patient's dietetic preferences may help avoid inadvertent prescription of the excipient gelatin in oral medications. Substitution of gelatin with vegetable-based alternatives and clearer labelling on drug packaging are alternative strategies to help minimise the risks of inadvertently contravening a patient's dietetic beliefs when prescribing oral medication.

Quantitative in vivo immunohistochemistry of epidermal growth factor receptor using a receptor concentration imaging approach

PubMed Central

Samkoe, Kimberley S.; Tichauer, Kenneth M.; Gunn, Jason R.; Wells, Wendy A.; Hasan, Tayyaba; Pogue, Brian W.

2014-01-01

As receptor-targeted therapeutics become increasingly used in clinical oncology, the ability to quantify protein expression and pharmacokinetics in vivo is imperative to ensure successful individualized treatment plans. Current standards for receptor analysis are performed on extracted tissues. These measurements are static and often physiologically irrelevant, therefore, only a partial picture of available receptors for drug targeting in vivo is provided. Until recently, in vivo measurements were limited by the inability to separate delivery, binding, and retention effects but this can be circumvented by a dual-tracer approach for referencing the detected signal. We hypothesized that in vivo receptor concentration imaging (RCI) would be superior to ex vivo immunohistochemistry. Using multiple xenograft tumor models with varying epidermal growth factor receptor (EGFR) expression, we determined the EGFR concentration in each model using a novel targeted agent (anti-EGFR affibody-IRDye800CW conjugate) along with a simultaneously delivered reference agent (control affibody-IRDye680RD conjugate). The RCI-calculated in vivo receptor concentration was strongly correlated with ex vivo pathologist-scored immunohistochemistry and computer-quantified ex vivo immunofluorescence. In contrast, no correlation was observed with ex vivo Western blot or in vitro flow cytometry assays. Overall, our results argue that in vivo RCI provides a robust measure of receptor expression equivalent to ex vivo immuno-staining, with implications for use in non-invasive monitoring of therapy or therapeutic guidance during surgery. PMID:25344226

Conformations of gelatin in trivalent chromium salt solutions: Viscosity and dynamic light scattering study

NASA Astrophysics Data System (ADS)

Qiao, Congde; Zhang, Jianlong; Kong, Aiqun

2017-02-01

An investigation of the influences of pH, salt type, and salt concentration on the conformations of gelatin molecules in trivalent chromium salt solutions was performed by viscosity and dynamic light scattering (DLS) techniques. It was found that the viscosity behaviors as polyelectrolytes or polyampholytes depended on the charge distribution on the gelatin chains, which can be tuned by the value of pH of the gelatin solution. The intrinsic viscosity of gelatin in basic chromium sulfate aqueous solution at pH = 2.0 first decreased and then increased with increasing Cr(OH)SO4 concentration, while a monotonic decrease of the intrinsic viscosity of gelatin was observed in CrCl3 solution. However, the intrinsic viscosity of gelatin at pH = 5.0 was found to be increased first and then decreased with an increase in salt concentration in Cr(OH)SO4 solution, as well as in CrCl3 solution. We suggested that the observed viscosity behavior of gelatin in trivalent chromium salt solutions was attributed to the comprehensive effects of shielding, overcharging, and crosslinking (complexation) caused by the introduction of the different counterions. In addition, the average hydrodynamic radius ( R h ) of gelatin molecules in various salt solutions was determined by DLS. It was found that the change trend of R h with salt concentration was the same as the change of intrinsic viscosity. Based on the results of the viscosity and DLS, a possible mechanism for the conformational transition of gelatin chains with external conditions including pH, salt concentration, and salt type is proposed.

Application of molecular targeted therapies in the treatment of head and neck squamous cell carcinoma.

PubMed

Kozakiewicz, Paulina; Grzybowska-Szatkowska, Ludmiła

2018-05-01

Despite the development of standard therapies, including surgery, radiotherapy and chemotherapy, survival rates for head and neck squamous cell carcinoma (HNSCC) have not changed significantly over the past three decades. Complete recovery is achieved in <50% of patients. The treatment of advanced HNSCC frequently requires multimodality therapy and involves significant toxicity. The promising, novel treatment option for patients with HNSCC is molecular-targeted therapies. The best known targeted therapies include: Epidermal growth factor receptor (EGFR) monoclonal antibodies (cetuximab, panitumumab, zalutumumab and nimotuzumab), EGFR tyrosine kinase inhibitors (gefitinib, erlotinib, lapatinib, afatinib and dacomitinib), vascular endothelial growth factor (VEGF) inhibitor (bevacizumab) or vascular endothelial growth factor receptor (VEGFR) inhibitors (sorafenib, sunitinib and vandetanib) and inhibitors of phosphatidylinositol 3-kinase/serine/threonine-specific protein kinase/mammalian target of rapamycin. There are also various inhibitors of other pathways and targets, which are promising and require evaluation in further studies.

Ligand Activation of TAM Family Receptors-Implications for Tumor Biology and Therapeutic Response.

PubMed

Davra, Viralkumar; Kimani, Stanley G; Calianese, David; Birge, Raymond B

2016-11-29

The TAM family of receptors (i.e., Tyro3, Axl, and Mertk), and their ligands Growth arrest specific factor 6 (Gas6) and Protein S (Pros1) contribute to several oncogenic processes, such as cell survival, invasion, migration, chemo-resistance, and metastasis, whereby expression often correlates with poor clinical outcomes. In recent years, there has been great interest in the study of TAM receptors in cancer, stemming both from their roles as oncogenic signaling receptors, as well as their roles in tumor immunology. As a result, several classes of TAM inhibitors that include small molecule tyrosine kinase inhibitors, monoclonal antibodies, decoy receptors, as well as novel strategies to target TAM ligands are being developed. This paper will review the biology of TAM receptors and their ligands with a focus on cancer, as well as evidence-based data for the continued pursuit of TAM/Gas6 inhibitors in clinical practice.

Targeted Therapies for Brain Metastases from Breast Cancer.

PubMed

Venur, Vyshak Alva; Leone, José Pablo

2016-09-13

The discovery of various driver pathways and targeted small molecule agents/antibodies have revolutionized the management of metastatic breast cancer. Currently, the major targets of clinical utility in breast cancer include the human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) receptor, mechanistic target of rapamycin (mTOR) pathway, and the cyclin-dependent kinase 4/6 (CDK-4/6) pathway. Brain metastasis, however, remains a thorn in the flesh, leading to morbidity, neuro-cognitive decline, and interruptions in the management of systemic disease. Approximately 20%-30% of patients with metastatic breast cancer develop brain metastases. Surgery, whole brain radiation therapy, and stereotactic radiosurgery are the traditional treatment options for patients with brain metastases. The therapeutic paradigm is changing due to better understanding of the blood brain barrier and the advent of tyrosine kinase inhibitors and monoclonal antibodies. Several of these agents are in clinical practice and several others are in early stage clinical trials. In this article, we will review the common targetable pathways in the management of breast cancer patients with brain metastases, and the current state of the clinical development of drugs against these pathways.

Orphan Nuclear Receptors as Targets for Drug Development

PubMed Central

Mukherjee, Subhajit

2012-01-01

Orphan nuclear receptors regulate diverse biological processes. These important molecules are ligand-activated transcription factors that act as natural sensors for a wide range of steroid hormones and xenobiotic ligands. Because of their importance in regulating various novel signaling pathways, recent research has focused on identifying xenobiotics targeting these receptors for the treatment of multiple human diseases. In this review, we will highlight these receptors in several physiologic and pathophysiologic actions and demonstrate how their functions can be exploited for the successful development of newer drugs. PMID:20372994

Targeting Nuclear EGFR: Strategies for Improving Cetuximab Therapy in Lung Cancer

DTIC Science & Technology

2014-09-01

Triple - negative breast cancer Mol Cancer Ther. 2014 May;13(5):1356-68. PMID: 24634415, PMCID: PMC4013210 6. Brand, TM, Iida, M...Receptor Is a Functional Molecular Target in Triple - Negative Breast Cancer . Molecular cancer therapeutics (2014). 11 26. Iida, M., Brand, T.M...2014). Brand, T.M., et al. Nuclear epidermal growth factor receptor is a functional molecular target in triple - negative breast cancer .

Optical cell separation from three-dimensional environment in photodegradable hydrogels for pure culture techniques.

PubMed

Tamura, Masato; Yanagawa, Fumiki; Sugiura, Shinji; Takagi, Toshiyuki; Sumaru, Kimio; Matsui, Hirofumi; Kanamori, Toshiyuki

2014-05-07

Cell sorting is an essential and efficient experimental tool for the isolation and characterization of target cells. A three-dimensional environment is crucial in determining cell behavior and cell fate in biological analysis. Herein, we have applied photodegradable hydrogels to optical cell separation from a 3D environment using a computer-controlled light irradiation system. The hydrogel is composed of photocleavable tetra-arm polyethylene glycol and gelatin, which optimized cytocompatibility to adjust a composition of crosslinker and gelatin. Local light irradiation could degrade the hydrogel corresponding to the micropattern image designed on a laptop; minimum resolution of photodegradation was estimated at 20 µm. Light irradiation separated an encapsulated fluorescent microbead without any contamination of neighbor beads, even at multiple targets. Upon selective separation of target cells in the hydrogels, the separated cells have grown on another dish, resulting in pure culture. Cell encapsulation, light irradiation and degradation products exhibited negligible cytotoxicity in overall process.

Comparison of starch and gelatin hydrogels for non-toxic supercapacitor electrolytes

NASA Astrophysics Data System (ADS)

Railanmaa, Anna; Lehtimäki, Suvi; Lupo, Donald

2017-06-01

Starch and gelatin are two of the most abundantly available natural polymers. Their non-toxicity, low cost, and compatibility with aqueous solvents make them ideal for use in ubiquitous, environmentally friendly electronics systems. This work presents the results of conductivity measurements through impedance spectroscopy for gelatin- and starch-based aqueous gel electrolytes. The NaCl-based gels were physically cross-linked. The conductivity values were 84.6 mS/cm at 1.5 mol L-1 and 71.5 mS/cm at 2 mol L-1 for gelatin and starch, respectively. The mechanical properties of gelatin were found preferable to those of starch, although they deteriorated significantly when the salt concentration exceeded 2 mol L-1. The ability of the gels to successfully act as a supercapacitor electrolyte was demonstrated with printed electrodes on plastic substrate. The devices were characterized through cyclic voltammetry measurements. The results imply that these polymer gel electrolytes are very promising for replacing the traditional aqueous liquid electrolytes in supercapacitors in applications where, for example, user and environmental safety is essential.

Gelatin and galactomannan-based scaffolds: Characterization and potential for tissue engineering applications.

PubMed

Siqueira, Nataly M; Paiva, Bruno; Camassola, Melissa; Rosenthal-Kim, Emily Q; Garcia, Ketlin C; dos Santos, Francisco P; Soares, Rosane M D

2015-11-20

In this work, we produced gelatin films containing different concentrations of galactomannan by casting solutions. The films were crosslinked by immersion in 30mM solution of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC). The crosslinking of gelatin-containing films was confirmed by the reduction of free amine band intensity (3400-3200cm(-1)) in the GEL IR, as well as by the evaluation of its behavior when immersed in phosphate-buffer solution. The crosslinking of galactomannan film was confirmed by the formation of new ether bonds, as observed by increasing intensity of the band at 1148cm(-1), and the reduction of OH band intensity (3600-3200cm(-1)). The presence of galactomannan and the crosslinking mediated by EDC were responsible to improve elasticity in the gelatin-based films. The samples did not show cytotoxicity during 24h or 48h. In addition, rat mesenchymal stem cells adhered to the films regardless of galactomannan concentration. The results indicated that the gelatin/galactomannan films are potential biomaterials for use as scaffolds for tissue engineering. Copyright © 2015 Elsevier Ltd. All rights reserved.

Determination of HIV-1 co-receptor usage.

PubMed

Cavarelli, Mariangela; Scarlatti, Gabriella

2014-01-01

Human immunodeficiency virus type I (HIV-1) infects target cells through interaction with the CD4 molecule and chemokine receptors, mainly the β-chemokine receptor 5 (CCR5) and the α-chemokine receptor 4 (CXCR4). Viral isolates can be phenotypically classified based on the co-receptor they utilize to infect target cells. In this chapter, methods to determine the co-receptor usage of HIV-1 variants are described.

The mapping of yeast's G-protein coupled receptor with an atomic force microscope

NASA Astrophysics Data System (ADS)

Takenaka, Musashi; Miyachi, Yusuke; Ishii, Jun; Ogino, Chiaki; Kondo, Akihiko

2015-03-01

An atomic force microscope (AFM) can measure the adhesion force between a sample and a cantilever while simultaneously applying a rupture force during the imaging of a sample. An AFM should be useful in targeting specific proteins on a cell surface. The present study proposes the use of an AFM to measure the adhesion force between targeting receptors and their ligands, and to map the targeting receptors. In this study, Ste2p, one of the G protein-coupled receptors (GPCRs), was chosen as the target receptor. The specific force between Ste2p on a yeast cell surface and a cantilever modified with its ligand, α-factor, was measured and found to be approximately 250 pN. In addition, through continuous measuring of the cell surface, a mapping of the receptors on the cell surface could be performed, which indicated the differences in the Ste2p expression levels. Therefore, the proposed AFM system is accurate for cell diagnosis.

Ridge augmentation using recombinant human fibroblast growth factor-2 with biodegradable gelatin sponges incorporating β-tricalcium phosphate: a preclinical study in dogs.

PubMed

Hoshi, S; Akizuki, T; Matsuura, T; Ikawa, T; Kinoshita, A; Oda, S; Tabata, Y; Matsui, M; Izumi, Y

2016-02-01

Fibroblast growth factor-2 (FGF-2) regulates the proliferation and differentiation of osteogenic cells, resulting in the promotion of bone formation. Biodegradable gelatin sponges incorporating β-tricalcium phosphate (β-TCP) have been reported as a scaffold, which has the ability to control growth factor release, offering sufficient mechanical strength and efficient migration of mesenchymal cells. In this study, we evaluated the effects of the combined use of recombinant human FGF-2 (rhFGF-2) and gelatin/β-TCP sponge on ridge augmentation in dogs. Six male beagle dogs were used in this study. Twelve wk after tooth extraction, bilateral 10 × 5 mm (width × depth) saddle-type defects were created 3 mm apart from the mesial side of the maxillary canine. At the experimental sites, the defects were filled with gelatin/β-TCP sponge infiltrated with 0.3% rhFGF-2, whereas gelatin/β-TCP sponge infiltrated with saline was applied to the control sites. Eight wk after surgery, qualitative and quantitative analyses were performed. There were no signs of clinical inflammation at 8 wk after surgery. Histometric measurements revealed that new bone height at the experimental sites (2.98 ± 0.65 mm) was significantly greater than that at the control sites (1.56 ± 0.66 mm; p = 0.004). The total tissue height was greater at the experimental sites (6.62 ± 0.66 mm) than that at the control sites (5.95 ± 0.74 mm), although there was no statistical significant difference (p = 0.051). Cast model measurements revealed that the residual defect height at the experimental sites (2.31 ± 0.50 mm) was significantly smaller than that at the control sites (3.51 ± 0.78 mm; p = 0.012). The combined use of rhFGF-2 and gelatin/β-TCP sponge promotes ridge augmentation in canine saddle-type bone defects. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Molecular and functional properties of gelatin from the skin of unicorn leatherjacket as affected by extracting temperatures.

PubMed

Kaewruang, Phanngam; Benjakul, Soottawat; Prodpran, Thummanoon

2013-06-01

Gelatins extracted from the skin of unicorn leatherjacket at different temperatures (45, 55, 65 and 75°C) in the presence and the absence of soybean trypsin inhibitor (SBTI; 100 units/g pretreated skin) for 12h were characterised. In general, the addition of SBTI resulted in the lower yield, regardless of extraction temperature. Higher yield was obtained when higher extraction temperature was used (P<0.05). Gelatin from skin extracted at 75°C in the absence of SBTI showed the highest yield (10.66 ± 0.41%) (based on dry weight). The highest α-amino group content was observed in gelatin extracted at 55°C without SBTI incorporated. The band intensity of β-chain and α-chains increased as the extraction temperature increased, particularly above 55°C. Gelatin extracted at 65°C with and without SBTI incorporation exhibited the highest gel strength (178.00 ± 7.50 g and 170.47 ± 1.30 g, respectively). FTIR spectra indicated that a greater loss of molecular order of triple helix with a higher degradation was found in gelatin extracted at 55°C in the absence SBTI. Gelatin extracted at 65°C, either with or without SBTI, had the highest EAI and ESI with high foam expansion and stability. Thus, the extraction of gelatin from the skin of unicorn leatherjacket at temperature sufficiently high could render the gelatin with less degradation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Minoxidil-induced hair growth is mediated by adenosine in cultured dermal papilla cells: possible involvement of sulfonylurea receptor 2B as a target of minoxidil.

PubMed

Li, M; Marubayashi, A; Nakaya, Y; Fukui, K; Arase, S

2001-12-01

The mechanism by which minoxidil, an adenosine-triphosphate-sensitive potassium channel opener, induces hypertrichosis remains to be elucidated. Minoxidil has been reported to stimulate the production of vascular endothelial growth factor, a possible promoter of hair growth, in cultured dermal papilla cells. The mechanism of production of vascular endothelial growth factor remains unclear, however. We hypothesize that adenosine serves as a mediator of vascular endothelial growth factor production. Minoxidil-induced increases in levels of intracellular Ca(2+) and vascular endothelial growth factor production in cultured dermal papilla cells were found to be inhibited by 8-sulfophenyl theophylline, a specific antagonist for adenosine receptors, suggesting that dermal papilla cells possess adenosine receptors and sulfonylurea receptors, the latter of which is a well-known target receptor for adenosine-triphosphate-sensitive potassium channel openers. The expression of sulfonylurea receptor 2B and of the adenosine A1, A2A, and A2B receptors was detected in dermal papilla cells by means of reverse transcription polymerase chain reaction analysis. In order to determine which of the adenosine receptor subtypes contribute to minoxidil-induced hair growth, the effects of subtype-specific antagonists for adenosine receptors were investigated. Significant inhibition in increase in intracellular calcium level by minoxidil or adenosine was observed as the result of pretreatment with 8-cyclopentyl-1,3-dipropylxanthine, an antagonist for adenosine A1 receptor, but not by 3,7-dimethyl-1-propargyl-xanthine, an antagonist for adenosine A2 receptor, whereas vascular endothelial growth factor production was blocked by both adenosine A1 and A2 receptor antagonists. These results indicate that the effect of minoxidil is mediated by adenosine, which triggers intracellular signal transduction via both adenosine A1 and A2 receptors, and that the expression of sulfonylurea receptor 2B in dermal papilla cells might play a role in the production of adenosine.

Structural basis for signal recognition and transduction by platelet-activating-factor receptor.

PubMed

Cao, Can; Tan, Qiuxiang; Xu, Chanjuan; He, Lingli; Yang, Linlin; Zhou, Ye; Zhou, Yiwei; Qiao, Anna; Lu, Minmin; Yi, Cuiying; Han, Gye Won; Wang, Xianping; Li, Xuemei; Yang, Huaiyu; Rao, Zihe; Jiang, Hualiang; Zhao, Yongfang; Liu, Jianfeng; Stevens, Raymond C; Zhao, Qiang; Zhang, Xuejun C; Wu, Beili

2018-06-01

Platelet-activating-factor receptor (PAFR) responds to platelet-activating factor (PAF), a phospholipid mediator of cell-to-cell communication that exhibits diverse physiological effects. PAFR is considered an important drug target for treating asthma, inflammation and cardiovascular diseases. Here we report crystal structures of human PAFR in complex with the antagonist SR 27417 and the inverse agonist ABT-491 at 2.8-Å and 2.9-Å resolution, respectively. The structures, supported by molecular docking of PAF, provide insights into the signal-recognition mechanisms of PAFR. The PAFR-SR 27417 structure reveals an unusual conformation showing that the intracellular tips of helices II and IV shift outward by 13 Å and 4 Å, respectively, and helix VIII adopts an inward conformation. The PAFR structures, combined with single-molecule FRET and cell-based functional assays, suggest that the conformational change in the helical bundle is ligand dependent and plays a critical role in PAFR activation, thus greatly extending knowledge about signaling by G-protein-coupled receptors.

Chimeric antigen receptor T cells: a novel therapy for solid tumors.

PubMed

Yu, Shengnan; Li, Anping; Liu, Qian; Li, Tengfei; Yuan, Xun; Han, Xinwei; Wu, Kongming

2017-03-29

The chimeric antigen receptor T (CAR-T) cell therapy is a newly developed adoptive antitumor treatment. Theoretically, CAR-T cells can specifically localize and eliminate tumor cells by interacting with the tumor-associated antigens (TAAs) expressing on tumor cell surface. Current studies demonstrated that various TAAs could act as target antigens for CAR-T cells, for instance, the type III variant epidermal growth factor receptor (EGFRvIII) was considered as an ideal target for its aberrant expression on the cell surface of several tumor types. CAR-T cell therapy has achieved gratifying breakthrough in hematological malignancies and promising outcome in solid tumor as showed in various clinical trials. The third generation of CAR-T demonstrates increased antitumor cytotoxicity and persistence through modification of CAR structure. In this review, we summarized the preclinical and clinical progress of CAR-T cells targeting EGFR, human epidermal growth factor receptor 2 (HER2), and mesothelin (MSLN), as well as the challenges for CAR-T cell therapy.

Biodegradable Bisvinyl Sulfonemethyl-crosslinked Gelatin Conduit Promotes Regeneration after Peripheral Nerve Injury in Adult Rats.

PubMed

Ko, Chien-Hsin; Shie, Ming-You; Lin, Jia-Horng; Chen, Yi-Wen; Yao, Chun-Hsu; Chen, Yueh-Sheng

2017-12-13

In our previous study, we found that gelatin-based materials exhibit good conductivity and are non-cytotoxic. In this study, gelatin was cross-linked with bisvinyl sulfonemethyl (BVSM) to fabricate a biodegradable conduit for peripheral nerve repair. First, BVSM on the prepared conduit was characterized to determine its mechanical properties and contact angle. The maximum tensile strength and water contact angle of the gelatin-BVSM conduits were 23 ± 4.8 MPa and 74.7 ± 9°, which provided sufficient mechanical strength to resist muscular contraction; additionally, the surface was hydrophilic. Cytotoxicity and apoptosis assays using Schwann cells demonstrated that the gelatin-BVSM conduits are non-cytotoxic. Next, we examined the neuronal electrophysiology, animal behavior, neuronal connectivity, macrophage infiltration, calcitonin gene-related peptide localization and expression, as well as the expression levels of nerve regeneration-related proteins. The number of fluorogold-labelled cells and histological analysis of the gelatin-BVSM nerve conduits was similar to that observed with the clinical use of silicone rubber conduits after 8 weeks of repair. Therefore, our results demonstrate that gelatin-BVSM conduits are promising substrates for application as bioengineered grafts for nerve tissue regeneration.

Analysis of HLA in children with gelatin allergy.

PubMed

Sakaguchi, M; Nakayama, T; Kaku, H; Taniguchi, K; Saito, S; Kimura, A; Inouye, S

2002-05-01

Systemic immediate reactions including anaphylaxis to gelatin in vaccines have been reported. However, the number of such reports is very small compared with the number of children exposed to gelatin. The present study was designed to investigate whether susceptibility or resistance to gelatin allergy is associated with human leukocyte antigen (HLA) class II gene. Blood samples were obtained from 49 patients with gelatin allergy and specific IgE to gelatin. DNA-based HLA class II typing was performed to determine the DRB1, DQB1 and DPB1 alleles. Genotype frequencies were compared with those found in 240 unrelated controls. The frequency of DQB1*0303 (55.1%) was significantly higher in the patients than in the control subjects (32.1%). The frequency of DPB1*0402 was also significantly higher in the patients (32.7%) than in the control subjects (15.4%). On the other hand, the frequency of subjects carrying DRB1*15 (DRB1*1501 and DRB1*1502) was significantly lower among the patients group (18.4%) than among the controls (40.8%). We found that DQB1*0303 and DPB1*0402 were positively associated with the IgE response for gelatin, while DRB1*15 was negatively associated with it.

A Multi-Receptor and Multi-Species Assay for Potential Endocrine Disruptor Targets (SLAS meeting)

EPA Science Inventory

Screening methods for detecting potential endocrine disrupting chemicals rely chiefly on transactivation assays targeting nuclear receptors such as the estrogen (ER) and androgen receptors (AR). These assays are predominately human-based; yet environmental exposure can affect div...

DNA methylation down-regulates EGFR expression in chicken

USDA-ARS?s Scientific Manuscript database

The epidermal growth factor receptor (EGFR), a growth-factor-receptor tyrosine kinase, was found up-regulated in numerous tumors, which provides a good target for cancer therapy. Although it was documented that oncoviruses are responsible for the activation of EGFR in tumors, the impact of Marek’s d...

Quantitative Impact of Plasma Clearance and Down-regulation on GLP-1 Receptor Molecular Imaging.

PubMed

Zhang, Liang; Thurber, Greg M

2016-02-01

Quantitative molecular imaging of beta cell mass (BCM) would enable early detection and treatment monitoring of type 1 diabetes. The glucagon-like peptide-1 (GLP-1) receptor is an attractive target due to its beta cell specificity and cell surface location. We quantitatively investigated the impact of plasma clearance and receptor internalization on targeting efficiency in healthy B6 mice. Four exenatide-based probes were synthesized that varied in molecular weight, binding affinity, and plasma clearance. The GLP-1 receptor internalization rate and in vivo receptor expression were quantified. Receptor internalization (54,000 receptors/cell in vivo) decreased significantly within minutes, reducing the benefit of a slower-clearing agent. The multimers and albumin binding probes had higher kidney and liver uptake, respectively. Slow plasma clearance is beneficial for GLP-1 receptor peptide therapeutics. However, for exendin-based imaging of islets, down-regulation of the GLP-1 receptor and non-specific background uptake result in a higher target-to-background ratio for fast-clearing agents.

Epidermal growth factor receptor and integrins control force-dependent vinculin recruitment to E-cadherin junctions.

PubMed

Sehgal, Poonam; Kong, Xinyu; Wu, Jun; Sunyer, Raimon; Trepat, Xavier; Leckband, Deborah

2018-03-20

This study reports novel findings that link E-cadherin (also known as CDH1)-mediated force-transduction signaling to vinculin targeting to intercellular junctions via epidermal growth factor receptor (EGFR) and integrins. These results build on previous findings that demonstrated that mechanically perturbed E-cadherin receptors activate phosphoinositide 3-kinase and downstream integrins in an EGFR-dependent manner. Results of this study show that this EGFR-mediated kinase cascade controls the force-dependent recruitment of vinculin to stressed E-cadherin complexes - a key early signature of cadherin-based mechanotransduction. Vinculin targeting requires its phosphorylation at tyrosine 822 by Abl family kinases (hereafter Abl), but the origin of force-dependent Abl activation had not been identified. We now present evidence that integrin activation, which is downstream of EGFR signaling, controls Abl activation, thus linking E-cadherin to Abl through a mechanosensitive signaling network. These findings place EGFR and integrins at the center of a positive-feedback loop, through which force-activated E-cadherin signals regulate vinculin recruitment to cadherin complexes in response to increased intercellular tension.This article has an associated First Person interview with the first author of the paper. © 2018. Published by The Company of Biologists Ltd.

Targeting the androgen receptor in prostate and breast cancer – several new agents in development

PubMed Central

Proverbs-Singh, Tracy; Feldman, Jarett L.; Morris, Michael J.; Autio, Karen A.; Traina, Tiffany A.

2016-01-01

Prostate cancer and breast cancer share similarities as hormone-sensitive cancers with a wide heterogeneity of both phenotype and biology. The androgen receptor (AR) is a hormone receptor involved in both benign and malignant processes. Targeting androgen synthesis and the AR pathway has been and remains central to prostate cancer therapy. Recently, there is increased interest in the role of the AR in breast cancer development and growth, with data suggesting AR co-expression with estrogen, progesterone and human epidermal growth factor receptors, across all intrinsic subtypes of breast cancer. Targeting the AR axis is an evolving field with novel therapies in development which may ultimately be applicable for both tumor types. In this review, we offer an overview of available agents which target the AR axis in both prostate and breast cancer and provide insight into the novel drugs in development for targeting this signaling pathway. PMID:25722318

Yersinia pestis targets neutrophils via complement receptor 3

PubMed Central

Merritt, Peter M.; Nero, Thomas; Bohman, Lesley; Felek, Suleyman; Krukonis, Eric S.; Marketon, Melanie M.

2015-01-01

Yersinia species display a tropism for lymphoid tissues during infection, and the bacteria select innate immune cells for delivery of cytotoxic effectors by the type III secretion system. Yet the mechanism for target cell selection remains a mystery. Here we investigate the interaction of Yersinia pestis with murine splenocytes to identify factors that participate in the targeting process. We find that interactions with primary immune cells rely on multiple factors. First, the bacterial adhesin Ail is required for efficient targeting of neutrophils in vivo. However, Ail does not appear to directly mediate binding to a specific cell type. Instead, we find that host serum factors direct Y. pestis to specific innate immune cells, particularly neutrophils. Importantly, specificity towards neutrophils was increased in the absence of bacterial adhesins due to reduced targeting of other cell types, but this phenotype was only visible in the presence of mouse serum. Addition of antibodies against complement receptor 3 and CD14 blocked target cell selection, suggesting that a combination of host factors participate in steering bacteria toward neutrophils during plague infection. PMID:25359083

Metformin is a novel suppressor for transforming growth factor (TGF)-β1

NASA Astrophysics Data System (ADS)

Xiao, Han; Zhang, Jianshu; Xu, Zhonghe; Feng, Yenan; Zhang, Mingliang; Liu, Jianli; Chen, Ruifei; Shen, Jing; Wu, Jimin; Lu, Zhizhen; Fang, Xiaohong; Li, Jingyuan; Zhang, Youyi

2016-06-01

Metformin is a widely used first-line antidiabetic drug that has been shown to protect against a variety of specific diseases in addition to diabetes, including cardiovascular disorders, polycystic ovary syndrome, and cancer. However, the precise mechanisms underlying the diverse therapeutic effects of metformin remain elusive. Here, we report that transforming growth factor-β1 (TGF-β1), which is involved in the pathogenesis of numerous diseases, is a novel target of metformin. Using a surface plasmon resonance-based assay, we identified the direct binding of metformin to TGF-β1 and found that metformin inhibits [125I]-TGF-β1 binding to its receptor. Furthermore, based on molecular docking and molecular dynamics simulations, metformin was predicted to interact with TGF-β1 at its receptor-binding domain. Single-molecule force spectroscopy revealed that metformin reduces the binding probability but not the binding force of TGF-β1 to its type II receptor. Consequently, metformin suppresses type II TGF-β1 receptor dimerization upon exposure to TGF-β1, which is essential for downstream signal transduction. Thus, our results indicate that metformin is a novel TGF-β suppressor with therapeutic potential for numerous diseases in which TGF-β1 hyperfunction is indicated.

Design, synthesis and screening studies of potent thiazol-2-amine derivatives as fibroblast growth factor receptor 1 inhibitors.

PubMed

Kumar, B V S Suneel; Lakshmi, Narasu; Kumar, M Ravi; Rambabu, Gundla; Manjashetty, Thimmappa H; Arunasree, Kalle M; Sriram, Dharmarajan; Ramkumar, Kavya; Neamati, Nouri; Dayam, Raveendra; Sarma, J A R P

2014-01-01

Fibroblast growth factor receptor 1 (FGFR1) a tyrosine kinase receptor, plays important roles in angiogenesis, embryonic development, cell proliferation, cell differentiation, and wound healing. The FGFR isoforms and their receptors (FGFRs) considered as a potential targets and under intense research to design potential anticancer agents. Fibroblast growth factors (FGF's) and its growth factor receptors (FGFR) plays vital role in one of the critical pathway in monitoring angiogenesis. In the current study, quantitative pharmacophore models were generated and validated using known FGFR1 inhibitors. The pharmacophore models were generated using a set of 28 compounds (training). The top pharmacophore model was selected and validated using a set of 126 compounds (test set) and also using external validation. The validated pharmacophore was considered as a virtual screening query to screen a database of 400,000 virtual molecules and pharmacophore model retrieved 2800 hits. The retrieved hits were subsequently filtered based on the fit value. The selected hits were subjected for docking studies to observe the binding modes of the retrieved hits and also to reduce the false positives. One of the potential hits (thiazole-2-amine derivative) was selected based the pharmacophore fit value, dock score, and synthetic feasibility. A few analogues of the thiazole-2-amine derivative were synthesized. These compounds were screened for FGFR1 activity and anti-proliferative studies. The top active compound showed 56.87% inhibition of FGFR1 activity at 50 µM and also showed good cellular activity. Further optimization of thiazole-2-amine derivatives is in progress.

Drug delivery with microsecond laser pulses into gelatin

NASA Astrophysics Data System (ADS)

Shangguan, Hanqun; Casperson, Lee W.; Shearin, Alan; Gregory, Kenton W.; Prahl, Scott A.

1996-07-01

Photoacoustic drug delivery is a technique for localized drug delivery by laser-induced hydrodynamic pressure following cavitation bubble expansion and collapse. Photoacoustic drug delivery was investigated on gelatin-based thrombus models with planar and cylindrical geometries by use of one microsecond laser pulses. Solutions of a hydrophobic dye in mineral oil permitted monitoring of delivered colored oil into clear gelatin-based thrombus models. Cavitation bubble development and photoacoustic drug delivery were visualized with flash photography. This study demonstrated that cavitation is the governing mechanism for photoacoustic drug delivery, and the deepest penetration of colored oil in gels followed the bubble collapse. Spatial distribution measurements revealed that colored oil could be driven a few millimeters into the gels in both axial and radial directions, and the penetration was less than 500 mu m when the gelatin structure was not fractured. localized drug delivery, cavitation bubble, laser thrombolysis.

Targeting the Neural Microenvironment in Prostate Cancer

DTIC Science & Technology

2016-10-01

neurotrophic factor (GDNF), which is expressed by peripheral nerves. GDNF binds to RET, a receptor tyrosine kinase, in conjunction with its co-receptor...kinase, in conjunction with its co- receptor GFRα1 and activates cellular signaling. Studies in pancreatic cancer strongly implicate RET signaling as

Identification of SR1078, a synthetic agonist for the orphan nuclear receptors RORα and RORγ.

PubMed

Wang, Yongjun; Kumar, Naresh; Nuhant, Philippe; Cameron, Michael D; Istrate, Monica A; Roush, William R; Griffin, Patrick R; Burris, Thomas P

2010-11-19

The retinoic acid receptor-related receptors (RORs) are members of the nuclear receptor (NR) superfamily of transcription factors. Several NRs are still characterized as orphan receptors because ligands have not yet been identified for these proteins. Here, we describe the identification of a synthetic RORα/RORγ ligand, SR1078. SR1078 modulates the conformation of RORγ in a biochemical assay and activates RORα and RORγ driven transcription. Furthermore, SR1078 stimulates expression of endogenous ROR target genes in HepG2 cells that express both RORα and RORγ. Pharmacokinetic studies indicate that SR1078 displays reasonable exposure following injection into mice, and consistent with SR1078 functioning as a RORα/RORγ agonist, expression of two ROR target genes, glucose-6-phosphatase and fibroblast growth factor 21, were stimulated in the liver. Thus, we have identified the first synthetic RORα/γ agonist, and this compound can be utilized as a chemical tool to probe the function of these receptors both in vitro and in vivo.

Identification of a Synthetic Agonist for the Orphan Nuclear Receptors RORα and RORγ, SR1078

PubMed Central

Wang, Yongjun; Kumar, Naresh; Nuhant, Philippe; Cameron, Michael D.; Istrate, Monica A.; Roush, William R.; Griffin, Patrick R.; Burris, Thomas P.

2010-01-01

The retinoic acid receptor-related receptors (RORs) are members of the nuclear receptor (NR) superfamily of transcription factors. Several NRs are still characterized as orphan receptors since ligands have not yet been identified for these proteins. Here, we describe the identification of a synthetic RORα/RORγ ligand, SR1078. SR1078 modulates the conformation of RORγ in a biochemical assay and activates RORα and RORγ driven transcription. Furthermore, SR1078 stimulates expression of endogenous ROR target genes in HepG2 cells that express both RORα and RORγ. Pharmacokinetic studies indicate that SR1078 displays reasonable exposure following injection into mice and consistent with SR1078 functioning as a RORα/RORγ agonist, expression of two ROR target genes, glucose-6-phosphatase and fibroblast growth factor 21, were stimulated in the liver. Thus, we have identified the first synthetic RORα/γ agonist and this compound can be utilized as a chemical tool to probe the function of these receptors both in vitro and in vivo. PMID:20735016

Fluorescence-Raman Dual Modal Endoscopic System for Multiplexed Molecular Diagnostics

NASA Astrophysics Data System (ADS)

Jeong, Sinyoung; Kim, Yong-Il; Kang, Homan; Kim, Gunsung; Cha, Myeong Geun; Chang, Hyejin; Jung, Kyung Oh; Kim, Young-Hwa; Jun, Bong-Hyun; Hwang, Do Won; Lee, Yun-Sang; Youn, Hyewon; Lee, Yoon-Sik; Kang, Keon Wook; Lee, Dong Soo; Jeong, Dae Hong

2015-03-01

Optical endoscopic imaging, which was recently equipped with bioluminescence, fluorescence, and Raman scattering, allows minimally invasive real-time detection of pathologies on the surface of hollow organs. To characterize pathologic lesions in a multiplexed way, we developed a dual modal fluorescence-Raman endomicroscopic system (FRES), which used fluorescence and surface-enhanced Raman scattering nanoprobes (F-SERS dots). Real-time, in vivo, and multiple target detection of a specific cancer was successful, based on the fast imaging capability of fluorescence signals and the multiplex capability of simultaneously detected SERS signals using an optical fiber bundle for intraoperative endoscopic system. Human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR) on the breast cancer xenografts in a mouse orthotopic model were successfully detected in a multiplexed way, illustrating the potential of FRES as a molecular diagnostic instrument that enables real-time tumor characterization of receptors during routine endoscopic procedures.

The intriguing biology of the tumour necrosis factor/tumour necrosis factor receptor superfamily: players, rules and the games.

PubMed

Hehlgans, Thomas; Pfeffer, Klaus

2005-05-01

The members of the tumour necrosis factor (TNF)/tumour necrosis factor receptor (TNFR) superfamily are critically involved in the maintenance of homeostasis of the immune system. The biological functions of this system encompass beneficial and protective effects in inflammation and host defence as well as a crucial role in organogenesis. At the same time, members of this superfamily are responsible for host damaging effects in sepsis, cachexia, and autoimmune diseases. This review summarizes recent progress in the immunobiology of the TNF/TNFR superfamily focusing on results obtained from animal studies using gene targeted mice. The different modes of signalling pathways affecting cell proliferation, survival, differentiation, apoptosis, and immune organ development as well as host defence are reviewed. Molecular and cellular mechanisms that demonstrate a therapeutic potential by targeting individual receptors or ligands for the treatment of chronic inflammatory or autoimmune diseases are discussed.

Hybrid chitosan-ß-glycerol phosphate-gelatin nano-/micro fibrous scaffolds with suitable mechanical and biological properties for tissue engineering.

PubMed

Lotfi, Marzieh; Bagherzadeh, Roohollah; Naderi-Meshkin, Hojjat; Mahdipour, Elahe; Mafinezhad, Asghar; Sadeghnia, Hamid Reza; Esmaily, Habibollah; Maleki, Masoud; Hasssanzadeh, Halimeh; Ghayaour-Mobarhan, Majid; Bidkhori, Hamid Reza; Bahrami, Ahmad Reza

2016-03-01

Scaffold-based tissue engineering is considered as a promising approach in the regenerative medicine. Graft instability of collagen, by causing poor mechanical properties and rapid degradation, and their hard handling remains major challenges to be addressed. In this research, a composite structured nano-/microfibrous scaffold, made from a mixture of chitosan-ß-glycerol phosphate-gelatin (chitosan-GP-gelatin) using a standard electrospinning set-up was developed. Gelatin-acid acetic and chitosan ß-glycerol phosphate-HCL solutions were prepared at ratios of 30/70, 50/50, 70/30 (w/w) and their mechanical and biological properties were engineered. Furthermore, the pore structure of the fabricated nanofibrous scaffolds was investigated and predicted using a theoretical model. Higher gelatin concentrations in the polymer blend resulted in significant increase in mean pore size and its distribution. Interaction between the scaffold and the contained cells was also monitored and compared in the test and control groups. Scaffolds with higher chitosan concentrations showed higher rate of cell attachment with better proliferation property, compared with gelatin-only scaffolds. The fabricated scaffolds, unlike many other natural polymers, also exhibit non-toxic and biodegradable properties in the grafted tissues. In conclusion, the data clearly showed that the fabricated biomaterial is a biologically compatible scaffold with potential to serve as a proper platform for retaining the cultured cells for further application in cell-based tissue engineering, especially in wound healing practices. These results suggested the potential of using mesoporous composite chitosan-GP-gelatin fibrous scaffolds for engineering three-dimensional tissues with different inherent cell characteristics. © 2015 Wiley Periodicals, Inc.

Shooting with sound: optimizing an affordable ballistic gelatin recipe in a graded ultrasound phantom education program.

PubMed

Tanious, Shariff F; Cline, Jamie; Cavin, Jennifer; Davidson, Nathan; Coleman, J Keegan; Goodmurphy, Craig W

2015-06-01

The goal of this study was to investigate the durability and longevity of gelatin formulas for the production of staged ultrasound phantoms for education. Gelatin phantoms were prepared from Knox gelatin (Kraft Foods, Northfield, IL) and a standard 10%-by-mass ordinance gelatin solution. Phantoms were durability tested by compressing to a 2-cm depth until cracking was visible. Additionally, 16 containers with varying combinations of phenol, container type, and storage location were tested for longevity against desiccation and molding. Once formulation was determined, 4 stages of phantoms from novice to clinically relevant were poured, and clinicians with ultrasound training ranked them on a 7-point Likert scale based on task difficulty, phantom suitability, and fidelity. On durability testing, the ballistic gelatin outperformed the Knox gelatin by more than 200 compressions. On longevity testing, gelatin with a 0.5% phenol concentration stored with a lid and refrigeration lasted longest, whereas containers without a lid had desiccation within 1 month, and those without phenol became moldy within 6 weeks. Ballistic gelatin was more expensive when buying in small quantities but was 7.4% less expensive when buying in bulk. The staged phantoms were deemed suitable for training, but clinicians did not consistently rank the phantoms in the intended order of 1 to 4 (44%). Refrigerated and sealed ballistic gelatin with phenol was a cost-effective method for creating in-house staged ultrasound phantoms suitable for large-scale ultrasound educational training needs. Clinician ranking of phantoms may be influenced by current training methods that favor biological tissue scanning as easier. © 2015 by the American Institute of Ultrasound in Medicine.

ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Cell surface receptors and associated signaling pathways).

PubMed

Aguilar-Company, J; Fernández-Ruiz, M; García-Campelo, R; Garrido-Castro, A C; Ruiz-Camps, I

2018-06-01

The present review is part of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) consensus document on the safety of targeted and biologic therapies. To review, from an infectious diseases perspective, the safety profile of therapies targeting cell surface receptors and associated signaling pathways among cancer patients and to suggest preventive recommendations. Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family. Vascular endothelial growth factor (VEGF)-targeted agents (bevacizumab and aflibercept) are associated with a meaningful increase in the risk of infection, likely due to drug-induced neutropaenia, although no clear benefit is expected from the universal use of anti-infective prophylaxis. VEGF tyrosine kinase inhibitors (i.e. sorafenib or sunitinib) do not seem to significantly affect host's susceptibility to infection, and universal anti-infective prophylaxis is not recommended either. Anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (cetuximab or panitumumab) induce neutropaenia and secondary skin and soft tissue infection in cases of severe papulopustular rash. Systemic antibiotics (doxycycline or minocycline) should be administered to prevent the latter complication, whereas no recommendation can be established on the benefit from antiviral, antifungal or anti-Pneumocystis prophylaxis. A lower risk of infection is reported for anti-ErbB2/HER2 monoclonal antibodies (trastuzumab and pertuzumab) and ErbB receptor tyrosine kinase inhibitors (including dual-EGFR/ErbB2 inhibitors such as lapatinib or neratinib) compared to conventional chemotherapy, presumably as a result of the decreased occurrence of drug-induced neutropaenia. With the exception of VEGF-targeted agents, the overall risk of infection associated with the reviewed therapies seems to be low. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Platelet-derived growth factor receptors differentially inform intertumoral and intratumoral heterogeneity

PubMed Central

Kim, Youngmi; Kim, Eunhee; Wu, Qiulian; Guryanova, Olga; Hitomi, Masahiro; Lathia, Justin D.; Serwanski, David; Sloan, Andrew E.; Weil, Robert J.; Lee, Jeongwu; Nishiyama, Akiko; Bao, Shideng; Hjelmeland, Anita B.; Rich, Jeremy N.

2012-01-01

Growth factor-mediated proliferation and self-renewal maintain tissue-specific stem cells and are frequently dysregulated in cancers. Platelet-derived growth factor (PDGF) ligands and receptors (PDGFRs) are commonly overexpressed in gliomas and initiate tumors, as proven in genetically engineered models. While PDGFRα alterations inform intertumoral heterogeneity toward a proneural glioblastoma (GBM) subtype, we interrogated the role of PDGFRs in intratumoral GBM heterogeneity. We found that PDGFRα is expressed only in a subset of GBMs, while PDGFRβ is more commonly expressed in tumors but is preferentially expressed by self-renewing tumorigenic GBM stem cells (GSCs). Genetic or pharmacological targeting of PDGFRβ (but not PDGFRα) attenuated GSC self-renewal, survival, tumor growth, and invasion. PDGFRβ inhibition decreased activation of the cancer stem cell signaling node STAT3, while constitutively active STAT3 rescued the loss of GSC self-renewal caused by PDGFRβ targeting. In silico survival analysis demonstrated that PDGFRB informed poor prognosis, while PDGFRA was a positive prognostic factor. Our results may explain mixed clinical responses of anti-PDGFR-based approaches and suggest the need for integration of models of cancer as an organ system into development of cancer therapies. PMID:22661233

Inhibiting the Epidermal Growth Factor Receptor | Center for Cancer Research

Cancer.gov

The Epidermal Growth Factor Receptor (EGFR) is a widely distributed cell surface receptor that responds to several extracellular signaling molecules through an intracellular tyrosine kinase, which phosphorylates target enzymes to trigger a downstream molecular cascade. Since the discovery that EGFR mutations and amplifications are critical in a number of cancers, efforts have been under way to develop and use targeted EGFR inhibitors. These efforts have met with some spectacular successes, but many patients have not responded as expected, have subsequently developed drug-resistant tumors, or have suffered serious side effects from the therapies to date. CCR Investigators are studying EGFR from multiple vantage points with the goal of developing even better strategies to defeat EGFR-related cancers.

PCL and PCL-gelatin nanofibers as esophageal tissue scaffolds: optimization, characterization and cell-matrix interactions.

PubMed

Kuppan, Purushothaman; Sethuraman, Swaminathan; Krishnan, Uma Maheswari

2013-09-01

Nanofiber based scaffolds offer great promise in regeneration of various tissues including esophagus. Diseases of the esophagus such as malignancy and strictures require surgical intervention to repair the affected region using an appropriate substitute. Long gap esophageal atresia poses a clinical challenge to bridge the gap. In this study, nanofibrous scaffolds made of PCL and PCL-gelatin were fabricated through electrospinning. The average diameter of PCL and PCL-gelatin nanofibers were found to be 324 +/- 50 nm and 242 +/- 30 nm respectively. PCL-gelatin nanofibers was characterized using FTIR, DSC, UTM, Goniometer, suture retention strength and in vitro degradation and the results were compared with the PCL nanofibers. PCL nanofiber characterization results showed that it exhibited higher tensile strength, suture retention strength, contact angle and slower degradation when compared with the PCL-gelatin nanofibers. Further, the interaction of human esophageal epithelial cells with PCL and PCL-gelatin nanofibrous scaffold was determined by cell adhesion, proliferation and gene expression studies. Our results demonstrated that the epithelial cells adhered and proliferated well on both PCL and PCL-gelatin nanofibrous scaffolds and also exhibited the characteristic cobblestone morphology. Cell proliferation on PCL-gelatin nanofibrous scaffold was significantly higher than the PCL nanofibrous scaffold (*p <0.05). Therefore, these scaffolds could be explored as potential candidates for regeneration of functional esophagus.

Highly efficient removal of lead and cadmium during wastewater irrigation using a polyethylenimine-grafted gelatin sponge

NASA Astrophysics Data System (ADS)

Li, Bingbing; Zhou, Feng; Huang, Kai; Wang, Yipei; Mei, Surong; Zhou, Yikai; Jing, Tao

2016-09-01

Wastewater irrigation is a very important resource for heavy metal pollution in soil and then accumulation in vegetable crops. In this study, a polyethylenimine (PEI)-grafted gelatin sponge was prepared to effectively adsorb heavy metals during wastewater irrigation. Based on the strong water adsorption ability, wastewater remained in the PEI-grafted gelatin sponge for a sufficient time for the heavy metals to interact with the sorbents. The binding capacities of Pb(II) ions and Cd(II) ions on the PEI-grafted gelatin sponge were 66 mg g-1 and 65 mg g-1, which were much more than those on the gelatin sponge (9.75 mg g-1 and 9.35 mg g-1). Subsequently, the PEI-grafted gelatin sponge was spread on the surface of soil planted with garlic and then sprayed with synthetic wastewater. The concentrations of cadmium and lead in the garlic leaves were 1.59 mg kg-1 and 5.69 mg kg-1, respectively, which were much lower than those (15.78 mg kg-1 and 27.98 mg kg-1) without the gelatin sponge, and the removal efficiencies were 89.9% and 79.7%. The PEI-grafting gelatin sponge could effectively remove heavy metals during wastewater irrigation, which improved the soil environment and reduced human exposure to heavy metals.

Electrospinning of gelatin with tunable fiber morphology from round to flat/ribbon.

PubMed

Topuz, Fuat; Uyar, Tamer

2017-11-01

The electrospinning of gelatin with tunable fiber morphology from round to flat/ribbon was shown, and the detailed studies were conducted to correlate the fiber morphology with electrospinning process parameters and gelatin concentration in electrospinning solution. Particularly, variations in the applied voltage and the concentration of gelatin led to the transition of fiber shape from round to flat/ribbon. The formation of flat-shaped fibers was attributed to rapid evaporation of the solvent (formic acid) from the fiber matrix with increasing the applied voltage and gelatin concentration. On the other hand, round fibers were due to the steady evaporation of formic acid throughout the cross-section of fibers. WAXS analysis revealed that the loss of triple-helical crystalline structure in gelatin after the electrospinning process. The gelatin fibers were cross-linked through treatment with toluene 2,4-diisocyanate (TDI) in a mixed solution of acetone and pyridine, and XPS confirmed the cross-linking of the fibers over an increased carbon content on the elemental composition of the fiber surface due to the incorporated TDI moieties. Overall, this study focuses on morphological tuning of gelatin electrospun fibers towards a flat/ribbon-like structure by variation of electrospinning parameters and polymer concentration, and thus, the proposed concept can be adapted towards flattened/ribbon-like fibers of other protein-based systems by electrospinning. Copyright © 2017 Elsevier B.V. All rights reserved.

Principles of antibody-mediated TNF receptor activation

PubMed Central

Wajant, H

2015-01-01

From the beginning of research on receptors of the tumor necrosis factor (TNF) receptor superfamily (TNFRSF), agonistic antibodies have been used to stimulate TNFRSF receptors in vitro and in vivo. Indeed, CD95, one of the first cloned TNFRSF receptors, was solely identified as the target of cell death-inducing antibodies. Early on, it became evident from in vitro studies that valency and Fcγ receptor (FcγR) binding of antibodies targeting TNFRSF receptors can be of crucial relevance for agonistic activity. TNFRSF receptor-specific antibodies of the IgM subclass and secondary cross-linked or aggregation prone dimeric antibodies typically display superior agonistic activity compared with dimeric antibodies. Likewise, anchoring of antibodies to cell surface-expressed FcγRs potentiate their ability to trigger TNFRSF receptor signaling. However, only recently has the relevance of oligomerization and FcγR binding for the in vivo activity of antibody-induced TNFRSF receptor activation been straightforwardly demonstrated in vivo. This review discusses the crucial role of oligomerization and/or FcγR binding for antibody-mediated TNFRSF receptor stimulation in light of current models of TNFRSF receptor activation and especially the overwhelming relevance of these issues for the rational development of therapeutic TNFRSF receptor-targeting antibodies. PMID:26292758

Quetiapine and aripiprazole signal differently to ERK, p90RSK and c-Fos in mouse frontal cortex and striatum: role of the EGF receptor

PubMed Central

2014-01-01

Background Signaling pathways outside dopamine D2 receptor antagonism may govern the variable clinical profile of antipsychotic drugs (APD) in schizophrenia. One postulated mechanism causal to APD action may regulate synaptic plasticity and neuronal connectivity via the extracellular signal-regulated kinase (ERK) cascade that links G-protein coupled receptors (GPCR) and ErbB growth factor signaling, systems disturbed in schizophrenia. This was based upon our finding that the low D2 receptor affinity APD clozapine induced initial down-regulation and delayed epidermal growth factor receptor (EGFR or ErbB1) mediated activation of the cortical and striatal ERK response in vivo distinct from olanzapine or haloperidol. Here we map whether the second generation atypical APDs aripiprazole and quetiapine affect the EGFR-ERK pathway and its substrates p90RSK and c-Fos in mouse brain, given their divergent agonist and antagonist properties on dopaminergic transmission, respectively. Results In prefrontal cortex, aripiprazole triggered triphasic ERK phosphorylation that was EGFR-independent but had no significant effect in striatum. Conversely quetiapine did not alter cortical ERK signaling but elevated striatal ERK levels in an EGFR-dependent manner. Induction of ERK by aripiprazole did not affect p90RSK signaling but quetiapine decreased RSK phosphorylation within 1-hour of administration. The transcription factor c-Fos by comparison was a direct target of ERK phosphorylation induced by aripiprazole in cortex and quetiapine in striatum with protein levels in temporal alignment with that of ERK. Conclusions These data indicate that aripiprazole and quetiapine signal to specific nuclear targets of ERK, which for quetiapine occurs via an EGFR-linked mechanism, possibly indicating involvement of this system in its action. PMID:24552586

Regulation of fibroblast growth factor receptor signalling and trafficking by Src and Eps8.

PubMed

Auciello, Giulio; Cunningham, Debbie L; Tatar, Tulin; Heath, John K; Rappoport, Joshua Z

2013-01-15

Fibroblast growth factor receptors (FGFRs) mediate a wide spectrum of cellular responses that are crucial for development and wound healing. However, aberrant FGFR activity leads to cancer. Activated growth factor receptors undergo stimulated endocytosis, but can continue to signal along the endocytic pathway. Endocytic trafficking controls the duration and intensity of signalling, and growth factor receptor signalling can lead to modifications of trafficking pathways. We have developed live-cell imaging methods for studying FGFR dynamics to investigate mechanisms that coordinate the interplay between receptor trafficking and signal transduction. Activated FGFR enters the cell following recruitment to pre-formed clathrin-coated pits (CCPs). However, FGFR activation stimulates clathrin-mediated endocytosis; FGF treatment increases the number of CCPs, including those undergoing endocytosis, and this effect is mediated by Src and its phosphorylation target Eps8. Eps8 interacts with the clathrin-mediated endocytosis machinery and depletion of Eps8 inhibits FGFR trafficking and immediate Erk signalling. Once internalized, FGFR passes through peripheral early endosomes en route to recycling and degredative compartments, through an Src- and Eps8-dependent mechanism. Thus Eps8 functions as a key coordinator in the interplay between FGFR signalling and trafficking. This work provides the first detailed mechanistic analysis of growth factor receptor clustering at the cell surface through signal transduction and endocytic trafficking. As we have characterised the Src target Eps8 as a key regulator of FGFR signalling and trafficking, and identified the early endocytic system as the site of Eps8-mediated effects, this work provides novel mechanistic insight into the reciprocal regulation of growth factor receptor signalling and trafficking.

Tumor Biology of Vestibular Schwannoma: A Review of Experimental Data on the Determinants of Tumor Genesis and Growth Characteristics.

PubMed

de Vries, Maurits; van der Mey, Andel G L; Hogendoorn, Pancras C W

2015-08-01

Provide an overview of the literature on vestibular schwannoma biology with special attention to tumor behavior and targeted therapy. Vestibular schwannomas are benign tumors originating from the eighth cranial nerve and arise due to inactivation of the NF2 gene and its product merlin. Unraveling the biology of these tumors helps to clarify their growth pattern and is essential in identifying therapeutic targets. PubMed search for English-language articles on vestibular schwannoma biology from 1994 to 2014. Activation of merlin and its role in cell signaling seem as key aspects of vestibular schwannoma biology. Merlin is regulated by proteins such as CD44, Rac, and myosin phosphatase-targeting subunit 1. The tumor-suppressive functions of merlin are related to receptor tyrosine kinases, such as the platelet-derived growth factor receptor and vascular endothelial growth factor receptor. Merlin mediates the Hippo pathway and acts within the nucleus by binding E3 ubiquiting ligase CRL4. Angiogenesis is an important mechanism responsible for the progression of these tumors and is affected by processes such as hypoxia and inflammation. Inhibiting angiogenesis by targeting vascular endothelial growth factor receptor seems to be the most successful pharmacologic strategy, but additional therapeutic options are emerging. Over the years, the knowledge on vestibular schwannoma biology has significantly increased. Future research should focus on identifying new therapeutic targets by investigating vestibular schwannoma (epi)genetics, merlin function, and tumor behavior. Besides identifying novel targets, testing new combinations of existing treatment strategies can further improve vestibular schwannoma therapy.

Dual targeting of glioblastoma with chimeric antigen receptor-engineered natural killer cells overcomes heterogeneity of target antigen expression and enhances antitumor activity and survival.

PubMed

Genßler, Sabrina; Burger, Michael C; Zhang, Congcong; Oelsner, Sarah; Mildenberger, Iris; Wagner, Marlies; Steinbach, Joachim P; Wels, Winfried S

2016-04-01

Epidermal growth factor receptor (EGFR) and its mutant form EGFRvIII are overexpressed in a large proportion of glioblastomas (GBM). Immunotherapy with an EGFRvIII-specific vaccine has shown efficacy against GBM in clinical studies. However, immune escape by antigen-loss variants and lack of control of EGFR wild-type positive clones limit the usefulness of this approach. Chimeric antigen receptor (CAR)-engineered natural killer (NK) cells may represent an alternative immunotherapeutic strategy. For targeting to GBM, we generated variants of the clinically applicable human NK cell line NK-92 that express CARs carrying a composite CD28-CD3ζ domain for signaling, and scFv antibody fragments for cell binding either recognizing EGFR, EGFRvIII, or an epitope common to both antigens. In vitro analysis revealed high and specific cytotoxicity of EGFR-targeted NK-92 against established and primary human GBM cells, which was dependent on EGFR expression and CAR signaling. EGFRvIII-targeted NK-92 only lysed EGFRvIII-positive GBM cells, while dual-specific NK cells expressing a cetuximab-based CAR were active against both types of tumor cells. In immunodeficient mice carrying intracranial GBM xenografts either expressing EGFR, EGFRvIII or both receptors, local treatment with dual-specific NK cells was superior to treatment with the corresponding monospecific CAR NK cells. This resulted in a marked extension of survival without inducing rapid immune escape as observed upon therapy with monospecific effectors. Our results demonstrate that dual targeting of CAR NK cells reduces the risk of immune escape and suggest that EGFR/EGFRvIII-targeted dual-specific CAR NK cells may have potential for adoptive immunotherapy of glioblastoma.

Targeted therapies in non-small cell lung carcinoma: what have we achieved so far?

PubMed Central

Houhou, Wissam

2013-01-01

The search for innovative therapeutic agents in non-small cell lung cancer (NSCLC) has witnessed a swift evolution. The number of targeted drugs that can improve patient outcomes with an acceptable safety profile is steadily increasing. In this review, we highlight current drugs that have already been approved or are under evaluation for the treatment of patients with NSCLC, either in monotherapy or combined therapy for both the first- and second-line settings. Experience with drugs targeting the vascular endothelial growth factor and its receptor, as well as the epidermal growth factor receptor is summarized. Moreover, we provide an overview of more novel targets in NSCLC and initial experience with the respective therapeutic agents. PMID:23858333

Biologically active and biomimetic dual gelatin scaffolds for tissue engineering.

PubMed

Sánchez, P; Pedraz, J L; Orive, G

2017-05-01

We have designed, developed and optimized Genipin cross-linked 3D gelatin scaffolds that were biologically active and biomimetic, show a dual activity both for growth factor and cell delivery. Type B gelatin powder was dissolved in DI water. 100mg of genipin was dissolved in 10ml of DI water. Three genipin concentrations were prepared: 0.1%, 0.2% and 0.3% (w/v). Solutions were mixed at 40°C and under stirring and then left crosslinking for 72h. Scaffolds were obtained by punching 8 mm-cylinders into ethanol 70% solution for 10min and then freeze-drying. Scaffolds were biologically, biomechanically and morphologically evaluated. Cell adhesion and morphology of D1-Mesenchymal stem cells (MSCs) and L-929 fibroblast was studied. Vascular endothelial grwoth factor (VEGF) and Sonic hedgehog (SHH) were used as model proteins. Swelling ratio increased and younǵs module decreased along with the concentration of genipin. All scaffolds were biocompatible according to the toxicity test. MSC and L-929 cell adhesion improved in 0.2% of genipin, obtaining better results with MSCs. VEGF and SHH were released from the gels. This preliminary study suggest that the biologically active and dual gelatin scaffolds may be used for tissue engineering approaches like bone regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

Biological substantiation of antipsychotic-associated pneumonia: Systematic literature review and computational analyses

PubMed Central

2017-01-01

Introduction Antipsychotic (AP) safety has been widely investigated. However, mechanisms underlying AP-associated pneumonia are not well-defined. Aim The aim of this study was to investigate the known mechanisms of AP-associated pneumonia through a systematic literature review, confirm these mechanisms using an independent data source on drug targets and attempt to identify novel AP drug targets potentially linked to pneumonia. Methods A search was conducted in Medline and Web of Science to identify studies exploring the association between pneumonia and antipsychotic use, from which information on hypothesized mechanism of action was extracted. All studies had to be in English and had to concern AP use as an intervention in persons of any age and for any indication, provided that the outcome was pneumonia. Information on the study design, population, exposure, outcome, risk estimate and mechanism of action was tabulated. Public repositories of pharmacology and drug safety data were used to identify the receptor binding profile and AP safety events. Cytoscape was then used to map biological pathways that could link AP targets and off-targets to pneumonia. Results The literature search yielded 200 articles; 41 were included in the review. Thirty studies reported a hypothesized mechanism of action, most commonly activation/inhibition of cholinergic, histaminergic and dopaminergic receptors. In vitro pharmacology data confirmed receptor affinities identified in the literature review. Two targets, thromboxane A2 receptor (TBXA2R) and platelet activating factor receptor (PTAFR) were found to be novel AP target receptors potentially associated with pneumonia. Biological pathways constructed using Cytoscape identified plausible biological links potentially leading to pneumonia downstream of TBXA2R and PTAFR. Conclusion Innovative approaches for biological substantiation of drug-adverse event associations may strengthen evidence on drug safety profiles and help to tailor pharmacological therapies to patient risk factors. PMID:29077727

Biological substantiation of antipsychotic-associated pneumonia: Systematic literature review and computational analyses.

PubMed

Sultana, Janet; Calabró, Marco; Garcia-Serna, Ricard; Ferrajolo, Carmen; Crisafulli, Concetta; Mestres, Jordi; Trifirò', Gianluca

2017-01-01

Antipsychotic (AP) safety has been widely investigated. However, mechanisms underlying AP-associated pneumonia are not well-defined. The aim of this study was to investigate the known mechanisms of AP-associated pneumonia through a systematic literature review, confirm these mechanisms using an independent data source on drug targets and attempt to identify novel AP drug targets potentially linked to pneumonia. A search was conducted in Medline and Web of Science to identify studies exploring the association between pneumonia and antipsychotic use, from which information on hypothesized mechanism of action was extracted. All studies had to be in English and had to concern AP use as an intervention in persons of any age and for any indication, provided that the outcome was pneumonia. Information on the study design, population, exposure, outcome, risk estimate and mechanism of action was tabulated. Public repositories of pharmacology and drug safety data were used to identify the receptor binding profile and AP safety events. Cytoscape was then used to map biological pathways that could link AP targets and off-targets to pneumonia. The literature search yielded 200 articles; 41 were included in the review. Thirty studies reported a hypothesized mechanism of action, most commonly activation/inhibition of cholinergic, histaminergic and dopaminergic receptors. In vitro pharmacology data confirmed receptor affinities identified in the literature review. Two targets, thromboxane A2 receptor (TBXA2R) and platelet activating factor receptor (PTAFR) were found to be novel AP target receptors potentially associated with pneumonia. Biological pathways constructed using Cytoscape identified plausible biological links potentially leading to pneumonia downstream of TBXA2R and PTAFR. Innovative approaches for biological substantiation of drug-adverse event associations may strengthen evidence on drug safety profiles and help to tailor pharmacological therapies to patient risk factors.

Evaluation of an In Vitro Multi-Receptor and Multi-Species Assay for Potential Endocrine Disruptor Targets (SOT)

EPA Science Inventory

Receptor sequence conservation across species may be a key factor determining susceptibility to potential endocrine disrupting chemicals. Computational approaches that compare receptor sequence similarities (e.g. SeqAPASS; https://seqapass.epa.gov/seqapass/) have been proposed to...

Gelatin-based hydrogel for vascular endothelial growth factor release in peripheral nerve tissue engineering.

PubMed

Gnavi, S; di Blasio, L; Tonda-Turo, C; Mancardi, A; Primo, L; Ciardelli, G; Gambarotta, G; Geuna, S; Perroteau, I

2017-02-01

Hydrogels are promising materials in regenerative medicine applications, due to their hydrophilicity, biocompatibility and capacity to release drugs and growth factors in a controlled manner. In this study, biocompatible and biodegradable hydrogels based on blends of natural polymers were used in in vitro and ex vivo experiments as a tool for VEGF-controlled release to accelerate the nerve regeneration process. Among different candidates, the angiogenic factor VEGF was selected, since angiogenesis has been long recognized as an important and necessary step during tissue repair. Recent studies have pointed out that VEGF has a beneficial effect on motor neuron survival and Schwann cell vitality and proliferation. Moreover, VEGF administration can sustain and enhance the growth of regenerating peripheral nerve fibres. The hydrogel preparation process was optimized to allow functional incorporation of VEGF, while preventing its degradation and denaturation. VEGF release was quantified through ELISA assay, whereas released VEGF bioactivity was validated in human umbilical vein endothelial cells (HUVECs) and in a Schwann cell line (RT4-D6P2T) by assessing VEGFR-2 and downstream effectors Akt and Erk1/2 phosphorylation. Moreover, dorsal root ganglia explants cultured on VEGF-releasing hydrogels displayed increased neurite outgrowth, providing confirmation that released VEGF maintained its effect, as also confirmed in a tubulogenesis assay. In conclusion, a gelatin-based hydrogel system for bioactive VEGF delivery was developed and characterized for its applicability in neural tissue engineering. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Modified gum arabic cross-linked gelatin scaffold for biomedical applications.

PubMed

Sarika, P R; Cinthya, Kuriakose; Jayakrishnan, A; Anilkumar, P R; James, Nirmala Rachel

2014-10-01

The present work deals with development of modified gum arabic cross-linked gelatin scaffold for cell culture. A new biocompatible scaffold was developed by cross-linking gelatin (Gel) with gum arabic, a polysaccharide. Gum arabic was subjected to periodate oxidation to obtain gum arabic aldehyde (GAA). GAA was reacted with gelatin under appropriate pH to prepare the cross-linked hydrogel. Cross-linking occurred due to Schiff's base reaction between aldehyde groups of oxidized gum arabic and amino groups of gelatin. The scaffold prepared from the hydrogel was characterized by swelling properties, degree of cross-linking, in vitro degradation and scanning electron microscopy (SEM). Cytocompatibility evaluation using L-929 and HepG2 cells confirmed non-cytotoxic and non-adherent nature of the scaffold. These properties are essential for generating multicellular spheroids and hence the scaffold is proposed to be a suitable candidate for spheroid cell culture. Copyright © 2014 Elsevier B.V. All rights reserved.

Gelatin based on Power-gel.TM. as solders for Cr.sup.4+laser tissue welding and sealing of lung air leak and fistulas in organs

DOEpatents

Alfano, Robert R.; Tang, Jing; Evans, Jonathan M.; Ho, Peng Pei

2006-04-25

Laser tissue welding can be achieved using tunable Cr.sup.4+ lasers, semiconductor lasers and fiber lasers, where the weld strength follows the absorption spectrum of water. The use of gelatin and esterified gelatin as solders in conjunction with laser inducted tissue welding impart much stronger tensile and torque strengths than albumin solders. Selected NIR wavelength from the above lasers can improve welding and avoid thermal injury to tissue when used alone or with gelatin and esterified gelatin solders. These discoveries can be used to enhance laser tissue welding of tissues such as skin, mucous, bone, blood vessel, nerve, brain, liver, pancreas, spleen, kidney, lung, bronchus, respiratory track, urinary tract, gastrointestinal tract, or gynecologic tract and as a sealant for pulmonary air leaks and fistulas such as intestinal, rectal and urinary fistulas.

MicroRNA regulation of viral immunity, latency, and carcinogenesis of selected tumor viruses and HIV.

PubMed

Wang, Ling; Li, Guangyu; Yao, Zhi Q; Moorman, Jonathan P; Ning, Shunbin

2015-09-01

MicroRNAs (miRNAs) function as key regulators in immune responses and cancer development. In the contexts of infection with oncogenic viruses, miRNAs are engaged in viral persistence, latency establishment and maintenance, and oncogenesis. In this review, we summarize the potential roles and mechanisms of viral and cellular miRNAs in the host-pathogen interactions during infection with selected tumor viruses and HIV, which include (i) repressing viral replication and facilitating latency establishment by targeting viral transcripts, (ii) evading innate and adaptive immune responses via toll-like receptors, RIG-I-like receptors, T-cell receptor, and B-cell receptor pathways by targeting signaling molecules such as TRAF6, IRAK1, IKKε, and MyD88, as well as downstream targets including regulatory cytokines such as tumor necrosis factor α, interferon γ, interleukin 10, and transforming growth factor β, (iii) antagonizing intrinsic and extrinsic apoptosis pathways by targeting pro-apoptotic or anti-apoptotic gene transcripts such as the Bcl-2 family and caspase-3, (iv) modulating cell proliferation and survival through regulation of the Wnt, PI3K/Akt, Erk/MAPK, and Jak/STAT signaling pathways, as well as the signaling pathways triggered by viral oncoproteins such as Epstein-Barr Virus LMP1, by targeting Wnt-inhibiting factor 1, SHIP, pTEN, and SOCSs, and (v) regulating cell cycle progression by targeting cell cycle inhibitors such as p21/WAF1 and p27/KIP1. Further elucidation of the interaction between miRNAs and these key biological events will facilitate our understanding of the pathogenesis of viral latency and oncogenesis and may lead to the identification of miRNAs as novel targets for developing new therapeutic or preventive interventions. Copyright © 2015 John Wiley & Sons, Ltd.

Evaluation of conditioning time and temperature on gelatinized starch and vitamin retention in a pelleted swine diet.

PubMed

Lewis, L L; Stark, C R; Fahrenholz, A C; Bergstrom, J R; Jones, C K

2015-02-01

Two key feed processing parameters, conditioning temperature and time, were altered to determine their effects on concentration of gelatinized starch and vitamin retention in a pelleted finishing swine diet. Diet formulation (corn–soybean meal based with 30% distillers dried grains with solubles) was held constant. Treatments were arranged in a 2 × 3 factorial design plus a control with 2 conditioning temperatures (77 vs. 88°C) and 3 conditioner retention times (15, 30, and 60 s). In addition, a mash diet not subjected to conditioning served as a control for a total of 7 treatments. Samples were collected after conditioning but before pelleting (hot mash), after pelleting but before cooling (hot pellet), and after pelleting and cooling (cold pellet) and analyzed for percentage total starch, percentage gelatinized starch, and riboflavin, niacin, and vitamin D3 concentrations. Total percentage starch was increased by greater conditioning temperature (P = 0.041) but not time (P > 0.10), whereas higher temperature and longer time both increased (P < 0.05) percentage gelatinized starch, with increasing time resulting in a linear increase in percentage starch gelatinization (P = 0.013). The interaction between conditioning temperature and time increased percentage gelatinized starch (P = 0.003) but not percentage total starch (P > 0.10). Sample location also affected both percentage total starch and gelatinized starch (P < 0.05), with the greatest increase in percentage gelatinized starch occurring between hot mash and hot pellet samples. As expected, the pelleting process increased percentage gelatinized starch (P = 0.035; 7.3 vs. 11.7% gelatinized starch for hot mash vs. hot pellet samples, respectively), but there was no difference in total starch concentrations (P > 0.10). Finally, neither conditioning temperature nor time affected riboflavin, niacin, or vitamin D3 concentrations (P > 0.10). In summary, both increasing conditioningtemperature and time effect percentage gelatinized starch, but not to the extent of forcing the diet through a pelleting die.

Formulation of multiparticulate systems as lyophilised orally disintegrating tablets.

PubMed

Alhusban, Farhan; Perrie, Yvonne; Mohammed, Afzal R

2011-11-01

The current study aimed to exploit the electrostatic associative interaction between carrageenan and gelatin to optimise a formulation of lyophilised orally disintegrating tablets (ODTs) suitable for multiparticulate delivery. A central composite face centred (CCF) design was applied to study the influence of formulation variables (gelatin, carrageenan and alanine concentrations) on the crucial responses of the formulation (disintegration time, hardness, viscosity and pH). The disintegration time and viscosity were controlled by the associative interaction between gelatin and carrageenan upon hydration which forms a strong complex that increases the viscosity of the stock solution and forms tablet with higher resistant to disintegration in aqueous medium. Therefore, the levels of carrageenan, gelatin and their interaction in the formulation were the significant factors. In terms of hardness, increasing gelatin and alanine concentration was the most effective way to improve tablet hardness. Accordingly, optimum concentrations of these excipients were needed to find the best balance that fulfilled all formulation requirements. The revised model showed high degree of predictability and optimisation reliability and therefore was successful in developing an ODT formulation with optimised properties that were able deliver enteric coated multiparticulates of omeprazole without compromising their functionality. Copyright © 2011 Elsevier B.V. All rights reserved.

Selective Glucocorticoid Receptor modulators.

PubMed

De Bosscher, Karolien

2010-05-31

The ancient two-faced Roman god Janus is often used as a metaphor to describe the characteristics of the Glucocorticoid Receptor (NR3C1), which exhibits both a beneficial side, that serves to halt inflammation, and a detrimental side responsible for undesirable effects. However, recent developments suggest that the Glucocorticoid Receptor has many more faces with the potential to express a range of different functionalities, depending on factors that include the tissue type, ligand type, receptor variants, cofactor surroundings and target gene promoters. This behavior of the receptor has made the development of safer ligands, that trigger the expression program of only a desirable subset of genes, a real challenge. Thus more knowledge-based fundamental research is needed to ensure the design and development of selective Glucocorticoid Receptor modulators capable of reaching the clinic. Recent advances in the characterization of novel selective Glucocorticoid Receptor modulators, specifically in the context of anti-inflammatory strategies, will be described in this review. 2010 Elsevier Ltd. All rights reserved.

Incidence of thromboembolic events after use of gelatin-thrombin-based hemostatic matrix during intracranial tumor surgery.

PubMed

Gazzeri, Roberto; Galarza, Marcelo; Conti, Carlo; De Bonis, Costanzo

2018-01-01

Association between the use of hemostatic agents made from collagen/gelatin mixed with thrombin and thromboembolic events in patients undergoing tumor resection has been suggested. This study evaluates the relationship between flowable hemostatic matrix and deep vein thrombosis in a large cohort of patients treated for brain tumor removal. The authors conducted a retrospective, multicenter, clinical review of all craniotomies for tumor removal performed between 2013 and 2014. Patients were classified in three groups: group I (flowable gelatin hemostatic matrix with thrombin), group II (gelatin hemostatic without thrombin), and group III (classical hemostatic). A total of 932 patients were selected: tumor pathology included 441 gliomas, 296 meningiomas, and 195 metastases. Thromboembolic events were identified in 4.7% of patients in which gelatin matrix with thrombin was applied, in 8.4% of patients with gelatin matrix without thrombin, and in 3.6% of cases with classical methods of hemostasis. Patients with venous thromboembolism had an increased proportion of high-grade gliomas (7.2%). Patients receiving a greater dose than 10 ml gelatin hemostatic had a higher rate of thromboembolic events. Intracranial hematoma requiring reintervention occurred in 19 cases: 4.5% of cases of group III, while reoperation was performed in 1.3 and 1.6% of patients in which gelatin matrix with or without thrombin was applied. Gelatin matrix hemostat is an efficacious tool for neurosurgeons in cases of difficult intraoperative bleeding during cranial tumor surgery. This study may help to identify those patients at high risk for developing thromboembolism and to treat them accordingly.

Recombinant immunotoxins and retargeted killer cells: employing engineered antibody fragments for tumor-specific targeting of cytotoxic effectors.

PubMed

Wels, Winfried; Biburger, Markus; Müller, Tina; Dälken, Benjamin; Giesübel, Ulrike; Tonn, Torsten; Uherek, Christoph

2004-03-01

Over the past years, monoclonal antibodies have attracted enormous interest as targeted therapeutics, and a number of such reagents are in clinical use. However, responses could not be achieved in all patients with tumors expressing high levels of the respective target antigens, suggesting that other factors such as limited recruitment of endogenous immune effector mechanisms can also influence treatment outcome. This justifies the search for alternative, potentially more effective reagents. Antibody-toxins and cytolytic effector cells genetically modified to carry antibody-based receptors on the surface, represent such tailor-made targeting vehicles with the potential of improved tumor localization and enhanced efficacy. In this way, advances in recombinant antibody technology have made it possible to circumvent problems inherent in chemical coupling of antibodies and toxins, and have allowed construction via gene fusion of recombinant molecules which combine antibody-mediated recognition of tumor cells with specific delivery of potent protein toxins of bacterial or plant origin. Likewise, recombinant antibody fragments provide the basis for the construction of chimeric antigen receptors that, upon expression in cytotoxic T lymphocytes (CTLs) or natural killer (NK) cells, link antibody-mediated recognition of tumor antigens with these effector cells' potent cytolytic activities, thereby making them promising cellular therapeutics for adoptive cancer therapy. Here, general principles for the derivation of cytotoxic proteins and effector cells with antibody-dependent tumor specificity are summarized, and current strategies to employ these molecules and cells for directed cancer therapy are discussed, focusing mainly on the tumor-associated antigens epidermal growth factor receptor (EGFR) and the closely related ErbB2 (HER2) as targets.

A study of a tissue equivalent gelatine based tissue substitute

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spence, J.L.

1992-11-01

A study of several tissue substitutes for use as volumetric dosimeters was performed. The tissue substitutes studied included tissue substitutes from previous studies and from ICRU 44. The substitutes were evaluated for an overall match to Reference Man which was used as a basis for this study. The evaluation was based on the electron stopping power, the mass attenuation coefficient, the electron density, and the specific gravity. The tissue substitute chosen also had to be capable of changing from a liquid into a solid form to maintain an even distribution of thermoluminesent dosimetry (TLD) powder and then back to amore » liquid for recovery of the TLD powder without adversely effecting the TLD powder. The gelatine mixture provided the closest match to the data from Reference Man tissue. The gelatine mixture was put through a series of test to determine it's usefulness as a reliable tissue substitute. The TLD powder was cast in the gelatine mixture and recovered to determine if the TLD powder was adversely effected. The distribution of the TLD powder after being cast into the gelatin mixture was tested in insure an even was maintained.« less

A study of a tissue equivalent gelatine based tissue substitute

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spence, Jody L.

1992-11-01

A study of several tissue substitutes for use as volumetric dosimeters was performed. The tissue substitutes studied included tissue substitutes from previous studies and from ICRU 44. The substitutes were evaluated for an overall match to Reference Man which was used as a basis for this study. The evaluation was based on the electron stopping power, the mass attenuation coefficient, the electron density, and the specific gravity. The tissue substitute chosen also had to be capable of changing from a liquid into a solid form to maintain an even distribution of thermoluminesent dosimetry (TLD) powder and then back to amore » liquid for recovery of the TLD powder without adversely effecting the TLD powder. The gelatine mixture provided the closest match to the data from Reference Man tissue. The gelatine mixture was put through a series of test to determine it`s usefulness as a reliable tissue substitute. The TLD powder was cast in the gelatine mixture and recovered to determine if the TLD powder was adversely effected. The distribution of the TLD powder after being cast into the gelatin mixture was tested in insure an even was maintained.« less

Cell signaling molecules as drug targets in lung cancer: an overview.

PubMed

Mukherjee, Tapan K; Paul, Karan; Mukhopadhyay, Srirupa

2011-07-01

Lung being one of the vital and essential organs in the body, lung cancer is a major cause of mortality in the modern human society. Lung cancer can be broadly subdivided into nonsmall cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Although NSCLC is sometimes treated with surgery, the advanced and metastatic NSCLC and SCLC usually respond better to chemotherapy and radiation. The most important targets of these chemotherapeutic agents are various intracellular signaling molecules. The primary focus of this review article is to summarize the description of various cell signaling molecules involved in lung cancer development and their regulation by chemotherapeutic agents. Extensive research work in recent years has identified several cellular signaling molecules that may be intricately involved in the complexity of lung cancer. Some of these cell signaling molecules are epidermal growth factor receptors, vascular endothelial growth factor receptors, mammalian target of rapamycin, mitogen-activated protein kinase phosphatase-1, peroxisome proliferator-activated receptor-gamma, matrix metalloproteinases and receptor for advanced glycation end-products. The present review will strengthen our current knowledge regarding the efficacy of the above-mentioned cell signaling molecules as potential beneficial drug targets against lung cancer.

Novel polymer blends with thermoplastic starch

NASA Astrophysics Data System (ADS)

Taghizadeh, Ata

A new class of polymers known as "bioplastics" has emerged and is expanding rapidly. This class consists of polymers that are either bio-based or biodegradable, or both. Among these, polysaccharides, namely starch, are of great interest for several reasons. By gelatinizing starch via plasticizers, it can be processed in the same way as thermoplastic polymers with conventional processing equipment. Hence, these bio-based and biodegradable plastics, with their low source and refinery costs, as well as relatively easy processability, have made them ideal candidates for incorporation into various current plastic products. Four different plasticizers have been chosen here for gelatinization of thermoplastic starch (TPS): glycerol, sorbitol, diglycerol and polyglycerol, with the latter two being used for the first time in such a process. Two methodological categories are used. The first involves a calorimetric method (Differential Scanning Calorimetry) as well as optical microscopy; these are "static" methods where no shear is applied A wide range of starch/water/plasticizer compositions were prepared to explore the gelatinization regime for each plasticizer. The onset and conclusion gelatinization temperatures for sorbitol and glycerol were found to be in the same vicinity, while diglycerol and polyglycerol showed significantly higher transition temperatures. The higher molecular weight and viscosity of polyglycerol allow this transition to occur at an even higher temperature than with diglycerol. This is due to the increase in molecular weight and viscosity of the two new plasticizers, as well as their significant decrease in water solubility. It is demonstrated that the water/plasticizer ratio has a pronounced effect on gelatinization temperatures. When plasticizer content was held constant and water content was increased, it was found that the gelatinization temperature decreased for all the plasticizers. Meanwhile, when the water content was held constant and the plasticizer content was increased, the gelatinization temperature increased for glycerol, sorbitol and diglycerol, but it moved in the opposite direction in the case of polyglycerol. The gelatinization temperature variation for glycerol, sorbitol and diglycerol caused by changing water and plasticizer content indicates that water is the primary agent causing granular swell and plasticization in the gelatinization process. Due to the high molecular weight and viscosity, as well as the low hydroxyl group density (~ one --OH per two carbon) and borderline solubility of polyglycerol in water, it is believed that water-aided penetration of the plasticizer among the crystalline structure of starch molecules is significantly decelerated. So it is proposed that in the case of low-water solubility of the plasticizers, gelatinization temperature is determined more by the total amount of the plasticizer and water, rather than the water/plasticizer ratio. Increasing the miscibility of polyglycerol in water by increasing the temperature of the initial slurry, results in a return of the system to the typical thermal dependence of gelatinization with plasticizer/water ratio. Secondly, the gelatinization of starch under "dynamic conditions" was studied. In this case, a constant shear is applied to the slurry, along with a temperature ramp to induce gelatinization. This is, in fact, a rheological technique that heats up the slurry, while a mechanical shear is applied throughout. The reason for using this method is that in the plastic industry, thermoplastic starch is produced via processes involving shear such as extrusion, but, to date, there has not yet been a thorough study on the effect of pure shear on the gelatinization process. Glycerol, diglycerol and sorbitol were subjected to different dynamic gelatinization treatments in a couette flow system, and the results were compared with static gelatinization. Applying shear showed virtually no effect on the onset gelatinization temperature. However, the conclusion temperature was remarkably reduced with the presence of shear. So it can be stated that the conclusion temperature is more kinetically driven (i.e. by applying high shear), so that complete gelatinization can be achieved in a shorter time-frame. (Abstract shortened by UMI.)

Rapid Activation of Bone Morphogenic Protein 9 by Receptor-mediated Displacement of Pro-domains*

PubMed Central

Kienast, Yvonne; Jucknischke, Ute; Scheiblich, Stefan; Thier, Martina; de Wouters, Mariana; Haas, Alexander; Lehmann, Christian; Brand, Verena; Bernicke, Dirk; Honold, Konrad; Lorenz, Stefan

2016-01-01

By non-covalent association after proteolytic cleavage, the pro-domains modulate the activities of the mature growth factor domains across the transforming growth factor-β family. In the case of bone morphogenic protein 9 (BMP9), however, the pro-domains do not inhibit the bioactivity of the growth factor, and the BMP9·pro-domain complexes have equivalent biological activities as the BMP9 mature ligand dimers. By using real-time surface plasmon resonance, we could demonstrate that either binding of pro-domain-complexed BMP9 to type I receptor activin receptor-like kinase 1 (ALK1), type II receptors, co-receptor endoglin, or to mature BMP9 domain targeting antibodies leads to immediate and complete displacement of the pro-domains from the complex. Vice versa, pro-domain binding by an anti-pro-domain antibody results in release of the mature BMP9 growth factor. Based on these findings, we adjusted ELISA assays to measure the protein levels of different BMP9 variants. Although mature BMP9 and inactive precursor BMP9 protein were directly detectable by ELISA, BMP9·pro-domain complex could only be measured indirectly as dissociated fragments due to displacement of mature growth factor and pro-domains after antibody binding. Our studies provide a model in which BMP9 can be readily activated upon getting into contact with its receptors. This increases the understanding of the underlying biology of BMP9 activation and also provides guidance for ELISA development for the detection of circulating BMP9 variants. PMID:26677222

Analysis of A Drug Target-based Classification System using Molecular Descriptors.

PubMed

Lu, Jing; Zhang, Pin; Bi, Yi; Luo, Xiaomin

2016-01-01

Drug-target interaction is an important topic in drug discovery and drug repositioning. KEGG database offers a drug annotation and classification using a target-based classification system. In this study, we gave an investigation on five target-based classes: (I) G protein-coupled receptors; (II) Nuclear receptors; (III) Ion channels; (IV) Enzymes; (V) Pathogens, using molecular descriptors to represent each drug compound. Two popular feature selection methods, maximum relevance minimum redundancy and incremental feature selection, were adopted to extract the important descriptors. Meanwhile, an optimal prediction model based on nearest neighbor algorithm was constructed, which got the best result in identifying drug target-based classes. Finally, some key descriptors were discussed to uncover their important roles in the identification of drug-target classes.

Emodin Suppresses Maintenance of Stemness by Augmenting Proteosomal Degradation of Epidermal Growth Factor Receptor/Epidermal Growth Factor Receptor Variant III in Glioma Stem Cells

PubMed Central

Kim, Jeongyub; Lee, Jong-Seon; Jung, Jieun; Lim, Inhye; Lee, Ji-Yun

2015-01-01

There is a growing body of evidence that small subpopulations of cells with stem cell-like characteristics within most solid tumors are responsible for the malignancy of aggressive cancer cells and that targeting these cells might be a good therapeutic strategy to reduce the risk of tumor relapse after therapy. Here, we examined the effects of emodin (1,3,8-trihydroxy-6-methylanthraquinone), an active component of the root and rhizome of Rheum palmatum that has several biological activities, including antitumor effects, on primary cultured glioma stem cells (GSCs). Emodin inhibited the self-renewal activity of GSCs in vitro as evidenced by neurosphere formation, limiting dilution, and soft agar clonogenic assays. Emodin inhibited the maintenance of stemness by suppressing the expression of Notch intracellular domain, nonphosphorylated β-catenin, and phosphorylated STAT3 proteins. In addition, treatment with emodin partially induced apoptosis, reduced cell invasiveness, and sensitized GSCs to ionizing radiation. Intriguingly, emodin induced proteosomal degradation of epidermal growth factor receptor (EGFR)/EGFR variant III (EGFRvIII) by interfering with the association of EGFR/EGFRvIII with heat shock protein 90, resulting in the suppression of stemness pathways. Based on these data, we propose that emodin could be considered as a potent therapeutic adjuvant that targets GSCs. PMID:25229646

Fibroblast growth factor receptors in breast cancer: expression, downstream effects, and possible drug targets.

PubMed

Tenhagen, M; van Diest, P J; Ivanova, I A; van der Wall, E; van der Groep, P

2012-08-01

Cancer treatments are increasingly focusing on the molecular mechanisms underlying the oncogenic processes present in tumors of individual patients. Fibroblast growth factor receptors (FGFRs) are among the many molecules that are involved in oncogenesis and are currently under investigation for their potential as drug targets in breast cancer patients. These receptor tyrosine kinases play a role in several processes including proliferation, angiogenesis, and migration. Alterations in these basal processes can contribute to the development and progression of tumors. Among breast cancer patients, several subgroups have been shown to harbor genetic aberrations in FGFRs, including amplifications of FGFR1, FGFR2, and FGFR4 and mutations in FGFR2 and FGFR4. Here, we review in vitro and in vivo models that have partly elucidated the molecular implications of these different genetic aberrations, the resulting tumor characteristics, and the potential of FGFRs as therapeutic targets for breast cancer treatment.

HER-3 peptide vaccines/mimics: Combined therapy with IGF-1R, HER-2, and HER-1 peptides induces synergistic antitumor effects against breast and pancreatic cancer cells.

PubMed

Miller, Megan Jo; Foy, Kevin C; Overholser, Jay P; Nahta, Rita; Kaumaya, Pravin Tp

2014-11-01

The human epidermal growth factor receptor 3 (HER-3/ErbB3) is a unique member of the human epidermal growth factor family of receptors, because it lacks intrinsic kinase activity and ability to heterodimerize with other members. HER-3 is frequently upregulated in cancers with epidermal growth factor receptor (EGFR/HER-1/ErbB1) or human epidermal growth factor receptor 2 (HER-2/ErBB2) overexpression, and targeting HER-3 may provide a route for overcoming resistance to agents that target EGFR or HER-2. We have previously developed vaccines and peptide mimics for HER-1, HER-2 and vascular endothelial growth factor (VEGF). In this study, we extend our studies by identifying and evaluating novel HER-3 peptide epitopes encompassing residues 99-122, 140-162, 237-269 and 461-479 of the HER-3 extracellular domain as putative B-cell epitopes for active immunotherapy against HER-3 positive cancers. We show that the HER-3 vaccine antibodies and HER-3 peptide mimics induced antitumor responses: inhibition of cancer cell proliferation, inhibition of receptor phosphorylation, induction of apoptosis and antibody dependent cellular cytotoxicity (ADCC). Two of the HER-3 epitopes 237-269 (domain II) and 461-479 (domain III) significantly inhibited growth of xenografts originating from both pancreatic (BxPC3) and breast (JIMT-1) cancers. Combined therapy of HER-3 (461-471) epitope with HER-2 (266-296), HER-2 (597-626), HER-1 (418-435) and insulin-like growth factor receptor type I (IGF-1R) (56-81) vaccine antibodies and peptide mimics show enhanced antitumor effects in breast and pancreatic cancer cells. This study establishes the hypothesis that combination immunotherapy targeting different signal transduction pathways can provide effective antitumor immunity and long-term control of HER-1 and HER-2 overexpressing cancers.

Co-targeting the HER and IGF/insulin receptor axis in breast cancer, with triple targeting with endocrine therapy for hormone-sensitive disease.

PubMed

Chakraborty, Ashok; Hatzis, Christos; DiGiovanna, Michael P

2017-05-01

Interactions between HER2, estrogen receptor (ER), and insulin-like growth factor I receptor (IGF1R) are implicated in resistance to monotherapies targeting these receptors. We have previously shown in pre-clinical studies synergistic anti-tumor effects for co-targeting each pairwise combination of HER2, IGF1R, and ER. Strikingly, synergy for HER2/IGF1R targeting occurred not only in a HER2+ model, but also in a HER2-normal model. The purpose of the current study was therefore to determine the generalizability of synergistic anti-tumor effects of co-targeting HER2/IGF1R, the anti-tumor activity of triple-targeting HER2/IGF1R/ER in hormone-dependent cell lines, and the effect of using the multi-targeting drugs neratinib (pan-HER) and BMS-754807 (dual IGF1R/insulin receptor). Proliferation and apoptosis assays were performed in a large panel of cell lines representing varying receptor expression levels. Mechanistic effects were studied using phospho-protein immunoblotting. Analyses of drug interaction effects were performed using linear mixed-effects regression models. Enhanced anti-proliferative effects of HER/IGF-insulin co-targeting were seen in most, though not all, cell lines, including HER2-normal lines. For ER+ lines, triple targeting with inclusion of anti-estrogen generally resulted in the greatest anti-tumor effects. Double or triple targeting generally resulted in marked increases in apoptosis in the sensitive lines. Mechanistic studies demonstrated that the synergy between drugs was correlated with maximal inhibition of Akt and ERK pathway signaling. Dual HER/IGF-insulin targeting, and triple targeting with inclusion of anti-estrogen drugs, shows striking anti-tumor activity across breast cancer types, and drugs with broader receptor specificity may be more effective than single receptor selective drugs, particularly for ER- cells.

A novel label-free cell-based assay technology using biolayer interferometry.

PubMed

Verzijl, D; Riedl, T; Parren, P W H I; Gerritsen, A F

2017-01-15

Biolayer interferometry (BLI) is a well-established optical label-free technique to study biomolecular interactions. Here we describe for the first time a cell-based BLI (cBLI) application that allows label-free real-time monitoring of signal transduction in living cells. Human A431 epidermoid carcinoma cells were captured onto collagen-coated biosensors and serum-starved, followed by exposure to agonistic compounds targeting various receptors, while recording the cBLI signal. Stimulation of the epidermal growth factor receptor (EGFR) with EGF, the β 2 -adrenoceptor with dopamine, or the hepatocyte growth factor receptor (HGFR/c-MET) with an agonistic antibody resulted in distinct cBLI signal patterns. We show that the mechanism underlying the observed changes in cBLI signal is mediated by rearrangement of the actin cytoskeleton, a process referred to as dynamic mass redistribution (DMR). A panel of ligand-binding blocking and non-blocking anti-EGFR antibodies was used to demonstrate that this novel BLI application can be efficiently used as a label-free cellular assay for compound screening and characterization. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Epidermal growth factor receptor and variant III targeted immunotherapy

PubMed Central

Congdon, Kendra L.; Gedeon, Patrick C.; Suryadevara, Carter M.; Caruso, Hillary G.; Cooper, Laurence J.N.; Heimberger, Amy B.; Sampson, John H.

2014-01-01

Immunotherapeutic approaches to cancer have shown remarkable promise. A critical barrier to successfully executing such immune-mediated interventions is the selection of safe yet immunogenic targets. As patient deaths have occurred when tumor-associated antigens shared by normal tissue have been targeted by strong cellular immunotherapeutic platforms, route of delivery, target selection and the immune-mediated approach undertaken must work together to maximize efficacy with safety. Selected tumor-specific targets can spare potential toxicity to normal tissue; however, they are far less common than tumor-associated antigens and may not be present on all patients. In the context of immunotherapy for high-grade glioma, 2 of the most prominently studied antigens are the tumor-associated epidermal growth factor receptor and its tumor-specific genetic deletion variant III. In this review, we will summarize the immune-mediated strategies employed against these targets as well as the caveats particular to these approaches. PMID:25342601

ROR nuclear receptors: structures, related diseases, and drug discovery

PubMed Central

Zhang, Yan; Luo, Xiao-yu; Wu, Dong-hai; Xu, Yong

2015-01-01

Nuclear receptors (NRs) are ligand-regulated transcription factors that regulate metabolism, development and immunity. The NR superfamily is one of the major classes of drug targets for human diseases. Retinoic acid receptor-related orphan receptor (ROR) α, β and γ belong to the NR superfamily, and these receptors are still considered as 'orphan' receptors because the identification of their endogenous ligands has been controversial. Recent studies have demonstrated that these receptors are regulated by synthetic ligands, thus emerge as important drug targets for the treatment of multiple sclerosis, rheumatoid arthritis, psoriasis, etc. Studying the structural basis and ligand development of RORs will pave the way for a better understanding of the roles of these receptors in human diseases. Here, we review the structural basis, disease relevance, strategies for ligand identification, and current status of development of therapeutic ligands for RORs. PMID:25500868

Targeting Epidermal Growth Factor Receptor-Related Signaling Pathways in Pancreatic Cancer.

PubMed

Philip, Philip A; Lutz, Manfred P

2015-10-01

Pancreatic cancer is aggressive, chemoresistant, and characterized by complex and poorly understood molecular biology. The epidermal growth factor receptor (EGFR) pathway is frequently activated in pancreatic cancer; therefore, it is a rational target for new treatments. However, the EGFR tyrosine kinase inhibitor erlotinib is currently the only targeted therapy to demonstrate a very modest survival benefit when added to gemcitabine in the treatment of patients with advanced pancreatic cancer. There is no molecular biomarker to predict the outcome of erlotinib treatment, although rash may be predictive of improved survival; EGFR expression does not predict the biologic activity of anti-EGFR drugs in pancreatic cancer, and no EGFR mutations are identified as enabling the selection of patients likely to benefit from treatment. Here, we review clinical studies of EGFR-targeted therapies in combination with conventional cytotoxic regimens or multitargeted strategies in advanced pancreatic cancer, as well as research directed at molecules downstream of EGFR as alternatives or adjuncts to receptor targeting. Limitations of preclinical models, patient selection, and trial design, as well as the complex mechanisms underlying resistance to EGFR-targeted agents, are discussed. Future clinical trials must incorporate translational research end points to aid patient selection and circumvent resistance to EGFR inhibitors.

RP-HPLC method using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate incorporated with normalization technique in principal component analysis to differentiate the bovine, porcine and fish gelatins.

PubMed

Azilawati, M I; Hashim, D M; Jamilah, B; Amin, I

2015-04-01

The amino acid compositions of bovine, porcine and fish gelatin were determined by amino acid analysis using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate as derivatization reagent. Sixteen amino acids were identified with similar spectral chromatograms. Data pre-treatment via centering and transformation of data by normalization were performed to provide data that are more suitable for analysis and easier to be interpreted. Principal component analysis (PCA) transformed the original data matrix into a number of principal components (PCs). Three principal components (PCs) described 96.5% of the total variance, and 2 PCs (91%) explained the highest variances. The PCA model demonstrated the relationships among amino acids in the correlation loadings plot to the group of gelatins in the scores plot. Fish gelatin was correlated to threonine, serine and methionine on the positive side of PC1; bovine gelatin was correlated to the non-polar side chains amino acids that were proline, hydroxyproline, leucine, isoleucine and valine on the negative side of PC1 and porcine gelatin was correlated to the polar side chains amino acids that were aspartate, glutamic acid, lysine and tyrosine on the negative side of PC2. Verification on the database using 12 samples from commercial products gelatin-based had confirmed the grouping patterns and the variables correlations. Therefore, this quantitative method is very useful as a screening method to determine gelatin from various sources. Copyright © 2014 Elsevier Ltd. All rights reserved.

Patterns of resource utilization and cost for postmenopausal women with hormone-receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer in Europe.

PubMed

Jerusalem, Guy; Neven, Patrick; Marinsek, Nina; Zhang, Jie; Degun, Ravi; Benelli, Giancarlo; Saletan, Stephen; Ricci, Jean-François; Andre, Fabrice

2015-10-24

Healthcare resource utilization in breast cancer varies by disease characteristics and treatment choices. However, lack of clarity in guidelines can result in varied interpretation and heterogeneous treatment management and costs. In Europe, the extent of this variability is unclear. Therefore, evaluation of chemotherapy use and costs versus hormone therapy across Europe is needed. This retrospective chart review (N = 355) examined primarily direct costs for chemotherapy versus hormone therapy in postmenopausal women with hormone-receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2-) advanced breast cancer across 5 European countries (France, Germany, The Netherlands, Belgium, and Sweden). Total direct costs across the first 3 treatment lines were approximately €10,000 to €14,000 lower for an additional line of hormone therapy-based treatment versus switching to chemotherapy-based treatment. Direct cost difference between chemotherapy-based and hormone therapy-based regimens was approximately €1900 to €2500 per month. Chemotherapy-based regimens were associated with increased resource utilization (managing side effects; concomitant targeted therapy use; and increased frequencies of hospitalizations, provider visits, and monitoring tests). The proportion of patients taking sick leave doubled after switching from hormone therapy to chemotherapy. These results suggest chemotherapy is associated with increased direct costs and potentially with increased indirect costs (lower productivity of working patients) versus hormone therapy in HR+, HER2- advanced breast cancer.

Aptamer-Mediated Codelivery of Doxorubicin and NF-κB Decoy Enhances Chemosensitivity of Pancreatic Tumor Cells

PubMed Central

Porciani, David; Tedeschi, Lorena; Marchetti, Laura; Citti, Lorenzo; Piazza, Vincenzo; Beltram, Fabio; Signore, Giovanni

2015-01-01

Aptamers able to bind efficiently cell-surface receptors differentially expressed in tumor and in healthy cells are emerging as powerful tools to perform targeted anticancer therapy. Here, we present a novel oligonucleotide chimera, composed by an RNA aptamer and a DNA decoy. Our assembly is able to (i) target tumor cells via an antitransferrin receptor RNA aptamer and (ii) perform selective codelivery of a chemotherapeutic drug (Doxorubicin) and of an inhibitor of a cell-survival factor, the nuclear factor κB decoy oligonucleotide. Both payloads are released under conditions found in endolysosomal compartments (low pH and reductive environment). Targeting and cytotoxicity of the oligonucleotidic chimera were assessed by confocal microscopy, cell viability, and Western blot analysis. These data indicated that the nuclear factor κB decoy does inhibit nuclear factor κB activity and ultimately leads to an increased therapeutic efficacy of Doxorubicin selectively in tumor cells. PMID:25919089

Gelatin- and starch-based hydrogels. Part B: In vitro mesenchymal stem cell behavior on the hydrogels.

PubMed

Van Nieuwenhove, Ine; Salamon, Achim; Adam, Stefanie; Dubruel, Peter; Van Vlierberghe, Sandra; Peters, Kirsten

2017-04-01

Tissue regeneration often occurs only to a limited extent. By providing a three-dimensional matrix serving as a surrogate extracellular matrix that promotes adult stem cell adhesion, proliferation and differentiation, scaffold-guided tissue regeneration aims at overcoming this limitation. In this study, we applied hydrogels made from crosslinkable gelatin, the hydrolyzed form of collagen, and functionalized starch which were characterized in depth and optimized as described in Van Nieuwenhove et al., 2016. "Gelatin- and Starch-Based Hydrogels. Part A: Hydrogel Development, Characterization and Coating", Carbohydrate Polymers 152:129-39. Collagen is the main structural protein in animal connective tissue and the most abundant protein in mammals. Starch is a carbohydrate consisting of a mixture of amylose and amylopectin. Hydrogels were developed with varying chemical composition (ratio of starch to gelatin applied) and different degrees of methacrylation of the applied gelatin phase. The hydrogels used exhibited no adverse effect on viability of the stem cells cultured on them. Moreover, initial cell adhesion did not differ significantly between them, while the strongest proliferation was observed on the hydrogel with the highest degree of cross-linking. On the least crosslinked and thus most flexible hydrogels, the highest degree of adipogenic differentiation was found, while osteogenic differentiation was the strongest on the most rigid, starch-blended hydrogels. Hydrogel coating with extracellular matrix compounds aggrecan or fibronectin prior to cell seeding exhibited no significant effects. Thus, gelatin-based hydrogels can be optimized regarding maximum promotion of either adipogenic or osteogenic stem cell differentiation in vitro, which makes them promising candidates for in vivo evaluation in clinical studies aiming at either soft or hard tissue regeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Distinct requirements for TrkB and TrkC signaling in target innervation by sensory neurons

NASA Technical Reports Server (NTRS)

Postigo, Antonio; Calella, Anna Maria; Fritzsch, Bernd; Knipper, Marlies; Katz, David; Eilers, Andreas; Schimmang, Thomas; Lewin, Gary R.; Klein, Rudiger; Minichiello, Liliana

2002-01-01

Signaling by brain-derived neurotrophic factor (BDNF) via the TrkB receptor, or by neurotrophin-3 (NT3) through the TrkC receptor support distinct populations of sensory neurons. The intracellular signaling pathways activated by Trk (tyrosine kinase) receptors, which in vivo promote neuronal survival and target innervation, are not well understood. Using mice with TrkB or TrkC receptors lacking the docking site for Shc adaptors (trkB(shc/shc) and trkC(shc/shc) mice), we show that TrkB and TrkC promote survival of sensory neurons mainly through Shc site-independent pathways, suggesting that these receptors use similar pathways to prevent apoptosis. In contrast, the regulation of target innervation appears different: in trkB(shc/shc) mice neurons lose target innervation, whereas in trkC(shc/shc) mice the surviving TrkC-dependent neurons maintain target innervation and function. Biochemical analysis indicates that phosphorylation at the Shc site positively regulates autophosphorylation of TrkB, but not of TrkC. Our findings show that although TrkB and TrkC signals mediating survival are largely similar, TrkB and TrkC signals required for maintenance of target innervation in vivo are regulated by distinct mechanisms.

Nuclear Transcription Factors in the Mitochondria: A New Paradigm in Fine-Tuning Mitochondrial Metabolism.

PubMed

Sepuri, Naresh Babu V; Tammineni, Prasad; Mohammed, Fareed; Paripati, Arunkumar

2017-01-01

Noncanonical functions of several nuclear transcription factors in the mitochondria have been gaining exceptional traction over the years. These transcription factors include nuclear hormone receptors like estrogen, glucocorticoid, and thyroid hormone receptors: p53, IRF3, STAT3, STAT5, CREB, NF-kB, and MEF-2D. Mitochondria-localized nuclear transcription factors regulate mitochondrial processes like apoptosis, respiration and mitochondrial transcription albeit being nuclear in origin and having nuclear functions. Hence, the cell permits these multi-stationed transcription factors to orchestrate and fine-tune cellular metabolism at various levels of operation. Despite their ubiquitous distribution in different subcompartments of mitochondria, their targeting mechanism is poorly understood. Here, we review the current status of mitochondria-localized transcription factors and discuss the possible targeting mechanism besides the functional interplay between these factors.

Identification of heparin-binding EGF-like growth factor as a target in intercellular regulation of epidermal basal cell growth by suprabasal retinoic acid receptors.

PubMed Central

Xiao, J H; Feng, X; Di, W; Peng, Z H; Li, L A; Chambon, P; Voorhees, J J

1999-01-01

The role of retinoic acid receptors (RARs) in intercellular regulation of cell growth was assessed by targeting a dominant-negative RARalpha mutant (dnRARalpha) to differentiated suprabasal cells of mouse epidermis. dnRARalpha lacks transcriptional activation but not DNA-binding and receptor dimerization functions. Analysis of transgenic mice revealed that dnRARalpha dose-dependently impaired induction of basal cell proliferation and epidermal hyperplasia by all-trans RA (tRA). dnRARalpha formed heterodimers with endogenous retinoid X receptor-alpha (RXRalpha) over RA response elements in competition with remaining endogenous RARgamma-RXRalpha heterodimers, and dose-dependently impaired retinoid-dependent gene transcription. To identify genes regulated by retinoid receptors and involved in cell growth control, we analyzed the retinoid effects on expression of the epidermal growth factor (EGF) receptor, EGF, transforming growth factor-alpha, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin genes. In normal epidermis, tRA rapidly and selectively induced expression of HB-EGF but not the others. This induction occurred exclusively in suprabasal cells. In transgenic epidermis, dnRARalpha dose-dependently inhibited tRA induction of suprabasal HB-EGF and subsequent basal cell hyperproliferation. Together, our observations suggest that retinoid receptor heterodimers located in differentiated suprabasal cells mediate retinoid induction of HB-EGF, which in turn stimulates basal cell growth via intercellular signaling. These events may underlie retinoid action in epidermal regeneration during wound healing. PMID:10075925

Bladder sensory physiology: neuroactive compounds and receptors, sensory transducers, and target-derived growth factors as targets to improve function

PubMed Central

Gonzalez, Eric J.; Merrill, Liana

2014-01-01

Urinary bladder dysfunction presents a major problem in the clinical management of patients suffering from pathological conditions and neurological injuries or disorders. Currently, the etiology underlying altered visceral sensations from the urinary bladder that accompany the chronic pain syndrome, bladder pain syndrome (BPS)/interstitial cystitis (IC), is not known. Bladder irritation and inflammation are histopathological features that may underlie BPS/IC that can change the properties of lower urinary tract sensory pathways (e.g., peripheral and central sensitization, neurochemical plasticity) and contribute to exaggerated responses of peripheral bladder sensory pathways. Among the potential mediators of peripheral nociceptor sensitization and urinary bladder dysfunction are neuroactive compounds (e.g., purinergic and neuropeptide and receptor pathways), sensory transducers (e.g., transient receptor potential channels) and target-derived growth factors (e.g., nerve growth factor). We review studies related to the organization of the afferent limb of the micturition reflex and discuss neuroplasticity in an animal model of urinary bladder inflammation to increase the understanding of functional bladder disorders and to identify potential novel targets for development of therapeutic interventions. Given the heterogeneity of BPS/IC and the lack of consistent treatment benefits, it is unlikely that a single treatment directed at a single target in micturition reflex pathways will have a mass benefit. Thus, the identification of multiple targets is a prudent approach, and use of cocktail treatments directed at multiple targets should be considered. PMID:24760999

Overexpression of androgen receptor and forkhead-box A1 protein in apocrine breast carcinoma.

PubMed

Sasahara, Manami; Matsui, Akira; Ichimura, Yoshiko; Hirakata, Yuuko; Murata, Yuuya; Marui, Eiji

2014-03-01

Apocrine breast carcinoma often lacks estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor type-2 (HER2) expression. Accordingly, development of a new treatment strategy is important for this type of cancer. The growth stimulus through the androgen receptor (AR) can be a candidate for targeted treatment. Therefore, we examined the factors related to AR transcription. We immunohistochemically evaluated 54 apocrine cancer lesions for ER, PgR, AR, HER2, Ki-67, forkhead-box protein A1 (FOXA1), and prostate-specific antigen (PSA) expression. ER, PgR, and HER2 were expressed at a low level, thus 44 out of 54 (81.4%) cases were of triple-negative breast cancer. AR, PSA and FOXA1 were expressed in 100% (54/54), 48% (26/54) and 93% (50/54) of cases, respectively. Most of apocrine breast carcinomas were immunohistochemically-positive for AR and FOXA1. Anti-androgenic therapies can potentially serve as a cancer-targeting therapy for apocrine breast carcinoma.

Factors affecting use of ballistics gelatin in laboratory studies of bacterial contamination in projectile wounds.

PubMed

Evans, Jessica J; Bost, Aaron; Muci-Küchler, Karim H; DeVeaux, Linda C

2018-05-25

Ballistics gelatin is a common tissue surrogate used in bacterial contamination models for projectile wounds. Although these studies have demonstrated that bacteria are transferred from the surface of the gelatin to the wound track by a projectile, quantifiable results have been inconsistent and not repeatable in successive tests. In this study, five areas of a typical contamination model in which bacterial recovery or survival are affected were identified for optimization. The first was a contaminated "skin" surrogate, where the novel use of vacuum filtration of a bacterial culture and buffer onto filter paper was employed. The other possibly problematic areas of the bacterial distribution model included the determination of bacterial survival when the contamination model is dried, survival in solid and molten gelatin, and the effect of high-intensity lights used for recording high-speed video. Vacuum filtration of bacteria and buffer resulted in a consistent bacterial distribution and recovery. The use of phosphate buffer M9 (pH 7) aided in neutralizing the ballistics gelatin and improving bacterial survival in solid gelatin. Additionally, the use of high-intensity lights to record high-speed video and the use of a 42 ° C water bath to melt the gelatin were found to be bactericidal for gram-positive and gram-negative bacteria. Multiple areas of a typical contamination model in which bacterial survival may be impeded were identified, and methods were proposed to improve survival in each area. These methods may be used to optimize the results of bacterial contamination models for medical applications, such as understanding the progression of infection in penetrating wounds and to identify possible sources of contamination for forensic purposes.

The 'triple contrast' method in experimental wound ballistics and backspatter analysis.

PubMed

Schyma, Christian; Lux, Constantin; Madea, Burkhard; Courts, Cornelius

2015-09-01

In practical forensic casework, backspatter recovered from shooters' hands can be an indicator of self-inflicted gunshot wounds to the head. In such cases, backspatter retrieved from inside the barrel indicates that the weapon found at the death scene was involved in causing the injury to the head. However, systematic research on the aspects conditioning presence, amount and specific patterns of backspatter is lacking so far. Herein, a new concept of backspatter investigation is presented, comprising staining technique, weapon and target medium: the 'triple contrast method' was developed, tested and is introduced for experimental backspatter analysis. First, mixtures of various proportions of acrylic paint for optical detection, barium sulphate for radiocontrast imaging in computed tomography and fresh human blood for PCR-based DNA profiling were generated (triple mixture) and tested for DNA quantification and short tandem repeat (STR) typing success. All tested mixtures yielded sufficient DNA that produced full STR profiles suitable for forensic identification. Then, for backspatter analysis, sealed foil bags containing the triple mixture were attached to plastic bottles filled with 10% ballistic gelatine and covered by a 2-3-mm layer of silicone. To simulate backspatter, close contact shots were fired at these models. Endoscopy of the barrel inside revealed coloured backspatter containing typable DNA and radiographic imaging showed a contrasted bullet path in the gelatine. Cross sections of the gelatine core exhibited cracks and fissures stained by the acrylic paint facilitating wound ballistic analysis.

Recent advances in hyaluronic acid-decorated nanocarriers for targeted cancer therapy

PubMed Central

Wickens, Jennifer M.; Alsaab, Hashem O.; Kesharwani, Prashant; Bhise, Ketki; Amin, Mohd Cairul Iqbal Mohd; Tekade, Rakesh Kumar; Gupta, Umesh; Iyer, Arun K.

2016-01-01

The cluster-determinant 44 (CD44) receptor has a high affinity for hyaluronic acid (HA) binding and is a desirable receptor for active targeting based on its overexpression in cancer cells compared with normal body cells. The nanocarrier affinity can be increased by conjugating drug-loaded carriers with HA, allowing enhanced cancer cell uptake via the HA-CD44 receptor-mediated endocytosis pathway. In this review, we discuss recent advances in HA-based nanocarriers and micelles for cancer therapy. In vitro and in vivo experiments have repeatedly indicated HA-based nanocarriers to be a target-specific drug and gene delivery platform with great promise for future applications in clinical cancer therapy. PMID:28017836

Early activation of quorum sensing in Pseudomonas aeruginosa reveals the architecture of a complex regulon.

PubMed

Schuster, Martin; Greenberg, E Peter

2007-08-22

Quorum-sensing regulation of gene expression in Pseudomonas aeruginosa is complex. Two interconnected acyl-homoserine lactone (acyl-HSL) signal-receptor pairs, 3-oxo-dodecanoyl-HSL-LasR and butanoyl-HSL-RhlR, regulate more than 300 genes. The induction of most of the genes is delayed during growth of P. aeruginosa in complex medium, cannot be advanced by addition of exogenous signal, and requires additional regulatory components. Many of these late genes can be induced by addition of signals early by using specific media conditions. While several factors super-regulate the quorum receptors, others may co-regulate target promoters or may affect expression posttranscriptionally. To better understand the contributions of super-regulation and co-regulation to quorum-sensing gene expression, and to better understand the general structure of the quorum sensing network, we ectopically expressed the two receptors (in the presence of their cognate signals) and another component that affects quorum sensing, the stationary phase sigma factor RpoS, early in growth. We determined the effect on target gene expression by microarray and real-time PCR analysis. Our results show that many target genes (e.g. lasB and hcnABC) are directly responsive to receptor protein levels. Most genes (e.g. lasA, lecA, and phnAB), however, are not significantly affected, although at least some of these genes are directly regulated by quorum sensing. The majority of promoters advanced by RhlR appeared to be regulated directly, which allowed us to build a RhlR consensus sequence. The direct responsiveness of many quorum sensing target genes to receptor protein levels early in growth confirms the role of super-regulation in quorum sensing gene expression. The observation that the induction of most target genes is not affected by signal or receptor protein levels indicates that either target promoters are co-regulated by other transcription factors, or that expression is controlled posttranscriptionally. This architecture permits the integration of multiple signaling pathways resulting in quorum responses that require a "quorum" but are otherwise highly adaptable and receptive to environmental conditions.

Cardioprotective role of G-Protein Coupled Estrogen Receptor 1 (GPER1).

PubMed

Koganti, Sivaramakrishna

2015-01-01

G-Protein Coupled Estrogen Receptor 1 (GPER1), also known as G-Protein Coupled Receptor 30 (GPR30) and initially considered an orphan receptor, has become one of the most important pharmacological targets in cardiovascular research. Since the gene encoding this putative receptor was cloned nearly 20 years ago, researchers have addressed its role in various aspects of physiology, including cardioprotection. Although extensive research has been carried out to understand the role of GPER1 as a pharmacological target to treat cardiovascular diseases, there are few current reviews addressing the overall cardioprotective benefits of this receptor and the signaling intermediates involved. This review considers the origins of GPER1, its cell biology, its physiological and pharmacological roles as a therapeutic target in cardiovascular disease, and what future research on GPER1 might entail. More specifically, the review focuses on GPER1 regulation of Angiotensin Type I Receptor (AT1R) and the role of estrogen receptors, epidermal growth factor receptor (EGFR) and matrix metalloproteinases (MMPs) in bringing about the cardioprotective effects of GPER1. Areas where improved knowledge of GPER1 biology is still needed to better understand the receptor's cardioprotective effects are also discussed.

Healing improvement after rotator cuff repair using gelatin-grafted poly(L-lactide) electrospun fibrous membranes.

PubMed

Zhao, Song; Xie, Xiaoxing; Pan, Guoqing; Shen, Peng; Zhao, Jinzhong; Cui, Wenguo

2015-01-01

Rotator cuff tears (RCTs) are a common cause of shoulder pain and disability in middle and older age. Despite improvements in the understanding of this disease process and advances in surgical treatment, rotator cuff (RC) repair failure rates remain high. Insufficient healing capacity is likely the main factor for failure of reconstruction. We fabricated implantable biodegradable gelatin-grafted poly(L-lactide) (PLLA) fibrous membranes using electrospinning technology and evaluated them using in vitro cell proliferation assays. Then, we established chronic rat RCT models and randomly assigned rats into one of three groups. In group 1 (n = 48), the detached supraspinatus tendon was repaired to its anatomic footprint (transosseous repair). In groups 2 and 3, the rats underwent transosseous repair and were implanted with either pure PLLA membranes (n = 48) or gelatin-PLLA membranes (n = 48) to augment the repairs. The animals were killed at 2, 4, and 8 wk postoperatively, which was followed by histomorphometric and biomechanical evaluation. Histologic observations revealed that gelatin-PLLA membranes have excellent biocompatibility and biodegradability. At 2, 4, and 8 wk postoperatively, the gelatin-PLLA membranes significantly increased the area of glycosaminoglycan staining at the tendon-bone interface compared with the control group (P < 0.05) and significantly improved collagen organization, as measured by birefringence under polarized light at the healing enthesis compared with the control and PLLA groups (P < 0.05). Biomechanical testing revealed that the gelatin-PLLA group had a greater ultimate load to failure and stiffness than the control group at 4 and 8 wk (P < 0.05). The gelatin-PLLA membranes had the highest stress of the healing enthesis. Local application of gelatin-PLLA fibrous membranes to the healing tendon-bone interface after RC repair in a rat chronic RCT model was found to strengthen the healing enthesis, increase the area of fibrocartilage, and improve collagen organization compared with repair alone. Augmentation with gelatin-grafted PLLA may enhance healing after RC repair and might eventually lead to improvement of clinical surgical outcomes. Copyright © 2015 Elsevier Inc. All rights reserved.

Antiangiogenic drugs synergize with a membrane macrophage colony-stimulating factor-based tumor vaccine to therapeutically treat rats with an established malignant intracranial glioma.

PubMed

Jeffes, Edward W B; Zhang, Jian Gang; Hoa, Neil; Petkar, Animesh; Delgado, Christina; Chong, Samuel; Obenaus, Andre; Sanchez, Ramon; Khalaghizadeh, Sakineh; Khomenko, Tetyana; Knight, Brandon A; Alipanah, Reza; Nguyen, Tuong-Vi; Shah, Chirag; Vohra, Seema; Zhuang, Jing-Li; Liu, Jessie; Wepsic, H Terry; Jadus, Martin R

2005-03-01

Combining a T9/9L glioma vaccine, expressing the membrane form of M-CSF, with a systemic antiangiogenic drug-based therapy theoretically targeted toward growth factor receptors within the tumor's vasculature successfully treated >90% of the rats bearing 7-day-old intracranial T9/9L gliomas. The antiangiogenic drugs included (Z)-3-[4-(dimethylamino)benzylidenyl]indolin-2-one (a platelet-derived growth factor receptor beta and a fibroblast growth factor receptor 1 kinase inhibitor) and oxindole (a vascular endothelial growth factor receptor 2 kinase inhibitor). A total of 20-40% of the animals treated with the antiangiogenic drugs alone survived, while all nontreated controls and tumor vaccine-treated rats died within 40 days. In vitro, these drugs inhibited endothelial cells from proliferating in response to the angiogenic factors produced by T9/9L glioma cells and prevented endothelial cell tubulogenesis. FITC-labeled tomato lectin staining demonstrated fewer and constricted blood vessels within the intracranial tumor after drug therapy. Magnetic resonance imaging demonstrated that the intracranial T9 glioma grew much slower in the presence of these antiangiogenic drugs. These drugs did not affect in vitro glioma cell growth nor T cell mitogenesis. Histological analysis revealed that the tumor destruction occurred at the margins of the tumor, where there was a heavy lymphocytic infiltrate. Real-time PCR showed more IL-2-specific mRNA was present within the gliomas in the vaccinated rats treated with the drugs. Animals that rejected the established T9/9L glioma by the combination therapy proved immune against an intracranial rechallenge by T9/9L glioma, but showed no resistance to an unrelated MADB106 breast cancer.

The Role of Mammalian Target of Rapamycin (mTOR) in Insulin Signaling.

PubMed

Yoon, Mee-Sup

2017-10-27

The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that controls a wide spectrum of cellular processes, including cell growth, differentiation, and metabolism. mTOR forms two distinct multiprotein complexes known as mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), which are characterized by the presence of raptor and rictor, respectively. mTOR controls insulin signaling by regulating several downstream components such as growth factor receptor-bound protein 10 (Grb10), insulin receptor substrate (IRS-1), F-box/WD repeat-containing protein 8 (Fbw8), and insulin like growth factor 1 receptor/insulin receptor (IGF-IR/IR). In addition, mTORC1 and mTORC2 regulate each other through a feedback loop to control cell growth. This review outlines the current understanding of mTOR regulation in insulin signaling in the context of whole body metabolism.

Evaluation of fibrin-gelatin hydrogel as biopaper for application in skin bioprinting: An in-vitro study.

PubMed

Hakam, Mohammad Sadjad; Imani, Rana; Abolfathi, Nabiollah; Fakhrzadeh, Hossein; Sharifi, Ali Mohammad

2016-01-01

Recent advances in tissue engineering have led to the development of the concept of bioprinting as an interesting alternative to traditional tissue engineering approaches. Biopaper, a biomimetic hydrogel, is an essential component of the bioprinting process. The aim of this work was to synthesize a biopaper made of fibrin-gelatin hybrid hydrogel for application in skin bioprinting. Different composition percentages of the two biopolymer hydrogels, fibrin-gelatin, have been studied for the construction of the biopaper and were examined in terms of water absorption, biodegradability, glucose absorption, mechanical properties and water vapor transmission. Subsequently, tissue fusion study was performed on prepared 3T3 fibroblast cell line pellets embedded into the hydrogel. Based on the obtained results, fibrin-gelatin blend hydrogel with the same proportion of two components provides a natural scaffold for fibroblast-based bioink embedding and culture. The suggested optimized hydrogel was a suitable candidate as a biopaper for skin bioprinting technology.

Gelatin-containing diphtheria-tetanus-pertussis (DTP) vaccine causes sensitization to gelatin in the recipients.

PubMed

Kumagai, T; Ozaki, T; Kamada, M; Igarashi, C; Yuri, K; Furukawa, H; Wagatuma, K; Chiba, S; Sato, M; Kojima, H; Saito, A; Okui, T; Yano, S

2000-02-14

Gelatin-specific T cell response was performed to determine whether a series of vaccinations with gelatin-containing DTP is a primary sensitization process in gelatin allergy. Thirty-seven recipients with gelatin-containing DTP who developed adverse reactions after vaccination and eight recipients of DTP without gelatin who also developed adverse reactions were studied. In addition, 10 subjects receiving gelatin-containing vaccine and 10 subjects inoculated with non-gelatin vaccine who did not show any adverse reactions were also investigated. All subjects inoculated with gelatin-containing DTP vaccine showed positive T cell responses against gelatin, however, occurrence of adverse reactions did not correlate with T cell responses. We conclude that DTP vaccine containing gelatin induces sensitization to gelatin in the recipients, but the mechanism of local reactions remains unknown.

Phosphatidylserine Sensing by TAM Receptors Regulates AKT-Dependent Chemoresistance and PD-L1 Expression.

PubMed

Kasikara, Canan; Kumar, Sushil; Kimani, Stanley; Tsou, Wen-I; Geng, Ke; Davra, Viralkumar; Sriram, Ganapathy; Devoe, Connor; Nguyen, Khanh-Quynh N; Antes, Anita; Krantz, Allen; Rymarczyk, Grzegorz; Wilczynski, Andrzej; Empig, Cyril; Freimark, Bruce; Gray, Michael; Schlunegger, Kyle; Hutchins, Jeff; Kotenko, Sergei V; Birge, Raymond B

2017-06-01

Tyro3, Axl, and Mertk (collectively TAM receptors) are three homologous receptor tyrosine kinases that bind vitamin K-dependent endogenous ligands, Protein S (ProS), and growth arrest-specific factor 6 (Gas6), and act as bridging molecules to promote phosphatidylserine (PS)-mediated clearance of apoptotic cells (efferocytosis). TAM receptors are overexpressed in a vast array of tumor types, whereby the level of expression correlates with the tumor grade and the emergence of chemo- and radioresistance to targeted therapeutics, but also have been implicated as inhibitory receptors on infiltrating myeloid-derived cells in the tumor microenvironment that can suppress host antitumor immunity. In the present study, we utilized TAM-IFNγR1 reporter lines and expressed TAM receptors in a variety of epithelial cell model systems to show that each TAM receptor has a unique pattern of activation by Gas6 or ProS, as well as unique dependency for PS on apoptotic cells and PS liposomes for activity. In addition, we leveraged this system to engineer epithelial cells that express wild-type TAM receptors and show that although each receptor can promote PS-mediated efferocytosis, AKT-mediated chemoresistance, as well as upregulate the immune checkpoint molecule PD-L1 on tumor cells, Mertk is most dominant in the aforementioned pathways. Functionally, TAM receptor-mediated efferocytosis could be partially blocked by PS-targeting antibody 11.31 and Annexin V, demonstrating the existence of a PS/PS receptor (i.e., TAM receptor)/PD-L1 axis that operates in epithelial cells to foster immune escape. These data provide a rationale that PS-targeting, anti-TAM receptor, and anti-PD-L1-based therapeutics will have merit as combinatorial checkpoint inhibitors. Implications: Many tumor cells are known to upregulate the immune checkpoint inhibitor PD-L1. This study demonstrates a role for PS and TAM receptors in the regulation of PD-L1 on cancer cells. Mol Cancer Res; 15(6); 753-64. ©2017 AACR . ©2017 American Association for Cancer Research.

From bench to bedside: What do we know about hormone receptor-positive and human epidermal growth factor receptor 2-positive breast cancer?

PubMed

Wu, Victoria Shang; Kanaya, Noriko; Lo, Chiao; Mortimer, Joanne; Chen, Shiuan

2015-09-01

Breast cancer is a heterogeneous disease. Thanks to extensive efforts from research scientists and clinicians, treatment for breast cancer has advanced into the era of targeted medicine. With the use of several well-established biomarkers, such as hormone receptors (HRs) (i.e., estrogen receptor [ER] and progesterone receptor [PgR]) and human epidermal growth factor receptor-2 (HER2), breast cancer patients can be categorized into multiple subgroups with specific targeted treatment strategies. Although therapeutic strategies for HR-positive (HR+) HER2-negative (HER2-) breast cancer and HR-negative (HR-) HER2-positive (HER2+) breast cancer are well-defined, HR+ HER2+ breast cancer is still an overlooked subgroup without tailored therapeutic options. In this review, we have summarized the molecular characteristics, etiology, preclinical tools and therapeutic options for HR+ HER2+ breast cancer. We hope to raise the attention of both the research and the medical community on HR+ HER2+ breast cancer, and to advance patient care for this subtype of disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

Molecularly-Targeted Gold-Based Nanoparticles for Cancer Imaging and Near-Infrared Photothermal Therapy

NASA Astrophysics Data System (ADS)

Day, Emily Shannon

2011-12-01

This thesis advances the use of nanoparticles as multifunctional agents for molecularly-targeted cancer imaging and photothermal therapy. Cancer mortality has remained relatively unchanged for several decades, indicating a significant need for improvements in care. Researchers are evaluating strategies incorporating nanoparticles as exogenous energy absorbers to deliver heat capable of inducing cell death selectively to tumors, sparing normal tissue. Molecular targeting of nanoparticles is predicted to improve photothermal therapy by enhancing tumor retention. This hypothesis is evaluated with two types of nanoparticles. The nanoparticles utilized, silica-gold nanoshells and gold-gold sulfide nanoparticles, can convert light energy into heat to damage cancerous cells. For in vivo applications nanoparticles are usually coated with poly(ethylene glycol) (PEG) to increase blood circulation time. Here, heterobifunctional PEG links nanoparticles to targeting agents (antibodies and growth factors) to provide cell-specific binding. This approach is evaluated through a series of experiments. In vitro, antibody-coated nanoparticles can bind breast carcinoma cells expressing the targeted receptor and act as contrast agents for multiphoton microscopy prior to inducing cell death via photoablation. Furthermore, antibody-coated nanoparticles can bind tissue ex vivo at levels corresponding to receptor expression, suggesting they should bind their target even in the complex biological milieu. This is evaluated by comparing the accumulation of antibody-coated and PEG-coated nanoparticles in subcutaneous glioma tumors in mice. Contrary to expectations, antibody targeting did not yield more nanoparticles within tumors. Nevertheless, these studies established the sensitivity of glioma to photothermal therapy; mice treated with PEG-coated nanoshells experienced 57% complete tumor regression versus no regression in control mice. Subsequent experiments employed intracranial tumors to better mimic the clinical setting. These tumors are highly vascularized, so nanoparticles were addressed toward receptors abundantly expressed on tumor vessels using growth factors as a novel targeting strategy. Photothermal therapy with these vascular-targeted nanoparticles disrupted tumor vessels, leading to a 2.2-fold prolongation of median survival versus control mice. This work confirms that nanoparticle surface coating can affect biodistribution and therapeutic efficacy. With continued optimization of molecular targeting strategies, imaging and photothermal therapy mediated by nanoshells and gold-gold sulfide nanoparticles may offer an effective alternative to conventional cancer management.

Plasticity of Human THP-1 Cell Phagocytic Activity during Macrophagic Differentiation.

PubMed

Kurynina, A V; Erokhina, M V; Makarevich, O A; Sysoeva, V Yu; Lepekha, L N; Kuznetsov, S A; Onishchenko, G E

2018-03-01

Studies of the role of macrophages in phagocytosis are of great theoretical and practical importance for understanding how these cells are involved in the organism's defense response and in the development of various pathologies. Here we investigated phagocytic plasticity of THP-1 (acute monocytic human leukemia) cells at different stages (days 1, 3, and 7) of phorbol ester (PMA)-induced macrophage differentiation. Analysis of cytokine profiles showed that PMA at a concentration of 100 nM induced development of the proinflammatory macrophage population. The functional activity of macrophages was assessed on days 3 and 7 of differentiation using unlabeled latex beads and latex beads conjugated with ligands (gelatin, mannan, and IgG Fc fragment) that bind to the corresponding specific receptors. The general phagocytic activity increased significantly (1.5-2.0-fold) in the course of differentiation; phagocytosis occurred mostly through the Fc receptors, as shown previously for M1 macrophages. On day 7, the levels of phagocytosis of gelatin- and Fc-covered beads were high; however, the intensity of ingestion of mannan-conjugated beads via mannose receptors increased 2.5-3.0-fold as well, which indicated formation of cells with an alternative phenotype similar to that of M2 macrophages. Thus, the type and the plasticity of phagocytic activity at certain stages of macrophage differentiation can be associated with the formation of functionally mature morphological phenotype. This allows macrophages to exhibit their phagocytic potential in response to specific ligands. These data are of fundamental importance and can be used to develop therapeutic methods for correcting the M1/M2 macrophage ratio in an organism.

Molecular targeting of growth factor receptor-bound 2 (Grb2) as an anti-cancer strategy.

PubMed

Dharmawardana, Pathirage G; Peruzzi, Benedetta; Giubellino, Alessio; Burke, Terrence R; Bottaro, Donald P

2006-01-01

Growth factor receptor-bound 2 (Grb2) is a ubiquitously expressed adapter protein that provides a critical link between cell surface growth factor receptors and the Ras signaling pathway. As such, it has been implicated in the oncogenesis of several important human malignancies. In addition to this function, research over the last decade has revealed other fundamental roles for Grb2 in cell motility and angiogenesis--processes that also contribute to tumor growth, invasiveness and metastasis. This functional profile makes Grb2 a high priority target for anti-cancer drug development. Knowledge of Grb2 protein structure, its component Src homology domains and their respective structure-function relationships has facilitated the rapid development of sophisticated drug candidates that can penetrate cells, bind Grb2 with high affinity and potently antagonize Grb2 signaling. These novel compounds offer considerable promise in our growing arsenal of rationally designed anti-cancer therapeutics.

Enhanced fluorescence diffuse optical tomography with indocyanine green-encapsulating liposomes targeted to receptors for vascular endothelial growth factor in tumor vasculature.

PubMed

Zanganeh, Saeid; Xu, Yan; Hamby, Carl V; Backer, Marina V; Backer, Joseph M; Zhu, Quing

2013-12-01

To develop an indocyanine green (ICG) tracer with slower clearance kinetics, we explored ICG-encapsulating liposomes (Lip) in three different formulations: untargeted (Lip/ICG), targeted to vascular endothelial growth factor (VEGF) receptors (scVEGF-Lip/ICG) by the receptor-binding moiety single-chain VEGF (scVEGF), or decorated with inactivated scVEGF (inactive-Lip/ICG) that does not bind to VEGF receptors. Experiments were conducted with tumor-bearing mice that were placed in a scattering medium with tumors located at imaging depths of either 1.5 or 2.0 cm. Near-infrared fluorescence diffuse optical tomography that provides depth-resolved spatial distributions of fluorescence in tumor was used for the detection of postinjection fluorescent signals. All liposome-based tracers, as well as free ICG, were injected intravenously into mice in the amounts corresponding to 5 nmol of ICG/mouse, and the kinetics of increase and decrease of fluorescent signals in tumors were monitored. A signal from free ICG reached maximum at 15-min postinjection and then rapidly declined with t1/2 of ~20 min. The signals from untargeted Lip/ICG and inactive-Lip/ICG also reached maximum at 15-min postinjection, however, declined somewhat slower than free ICG with t1/2 of ~30 min. By contrast, a signal from targeted scVEGF-Lip/ICG grew slower than that of all other tracers, reaching maximum at 30-min postinjection and declined much slower than that of other tracers with t1/2 of ~90 min, providing a more extended observation window. Higher scVEGF-Lip/ICG tumor accumulation was further confirmed by the analysis of fluorescence on cryosections of tumors that were harvested from animals at 400 min after injection with different tracers.

Antibody Targeting of Caveolae in Breast Tumors

DTIC Science & Technology

2004-08-01

regulatory cofactor NHE-RF2; P2X7, " P2X purinergic receptor 7; Podo, podocalyxin; RAGE, receptor for advanced glycation end products; STR, seven...subtractive proteomics and molecular imaging in vivo." (San Diego, CA) 2004 Keystone Symposia, G-Protein-Coupled Receptors : Evolving Concepts and Drug...34 (Rochester, MN) 8 Schnitzer, Jan E., M.D. DAMD 1-02-1-0563 2004 Second International Conference on Vascular Targeting, Ligand Based Vascular Targeting

Reactivity of the immunoglobulin E in bovine gelatin-sensitive children to gelatins from various animals

PubMed Central

Sakaguchi, M; Hori, H; Ebihara, T; Irie, S; Yanagida, M; Inouye, S

1999-01-01

It has been reported that most children who showed anaphylaxis to measles, mumps and rubella vaccines containing bovine gelatin as a stabilizer have anti-bovine gelatin IgE. The present study was designed to investigate the reactivity of IgE in bovine gelatin-sensitive children to gelatins from various animals, and the antigenic cross-reactivity between the gelatins. Serum samples taken from 10 children who showed anaphylaxis to vaccines containing bovine gelatin were used in this study. The level of anti-bovine gelatin IgE in these serum samples ranged from 11·0 to 251 Ua/ml. The IgE in most of the children reacted to kangaroo and mouse gelatins, to which they had had little or no exposure as a food or a vaccine stabilizer. The IgE binding to kangaroo and mouse gelatins was completely inhibited by bovine gelatin, whereas reciprocal inhibition was not complete, indicating that antigenic cross-reactivity is present between the mammalian gelatins. Only one child had strong IgE reactivity to fish gelatins, and this reactivity was not inhibited by bovine gelatin, indicating that no antigenic cross-reactivity exists between bovine and fish gelatins. Most of the children who displayed sensitivity to bovine gelatin showed IgE reactivity to other mammalian gelatins. This reactivity may be due primarily to the antigenic cross-reactivity between mammalian gelatins. PMID:10233707

Shock Wave Based Biolistic Device for DNA and Drug Delivery

NASA Astrophysics Data System (ADS)

Nakada, Mutsumi; Menezes, Viren; Kanno, Akira; Hosseini, S. Hamid R.; Takayama, Kazuyoshi

2008-03-01

A shock wave assisted biolistic (biological ballistic) device has been developed to deliver DNA/drug-coated micro-projectiles into soft living targets. The device consists of an Nd:YAG laser, an optical setup to focus the laser beam and, a thin aluminum (Al) foil (typically 100 µm thick) which is a launch pad for the micro-projectiles. The DNA/drug-coated micro-particles to be delivered are deposited on the anterior surface of the foil and the posterior surface of the foil is ablated using the laser beam with an energy density of about 32×109 W/cm2. The ablation launches a shock wave through the foil that imparts an impulse to the foil surface, due to which the deposited particles accelerate and acquire sufficient momentum to penetrate soft targets. The device has been tested for particle delivery by delivering 1 µm size tungsten particles into liver tissues of experimental rats and in vitro test models made of gelatin. The penetration depths of about 90 and 800 µm have been observed in the liver and gelatin targets, respectively. The device has been tested for in vivo DNA [encoding β-glucuronidase (GUS) gene] transfer by delivering plasmid DNA-coated, 1-µm size gold (Au) particles into onion scale, tobacco leaf and soybean seed cells. The GUS activity was detected in the onion, tobacco and soybean cells after the DNA delivery. The present device is totally non-intrusive in nature and has a potential to get miniaturized to suit the existing medical procedures for DNA and/or drug delivery.

Effect of pH, water activity and gel micro-structure, including oxygen profiles and rheological characterization, on the growth kinetics of Salmonella Typhimurium.

PubMed

Theys, T E; Geeraerd, A H; Verhulst, A; Poot, K; Van Bree, I; Devlieghere, F; Moldenaers, P; Wilson, D; Brocklehurst, T; Van Impe, J F

2008-11-30

In this study, the growth of Salmonella Typhimurium in Tryptic Soy Broth was examined at different pH (4.50-5.50), water activity a(w) (0.970-0.992) and gelatin concentration (0%, 1% and 5% ) at 20 degrees C. Experiments in TSB with 0% gelatin were carried out in shaken erlenmeyers, in the weak 1% gelatin media in petri plates and in the firm 5% gelatin media in gel cassettes. A quantification of gel strength was performed by rheological measurements and the influence of oxygen supply on the growth of S. Typhimurium was investigated. pH, as well as a(w) as well as gelatin concentration had an influence on the growth rate. Both in broth and in gelatinized media, lowering pH or water activity caused a decrease of growth rate. In media with 1% gelatin a reduction of growth rate and maximal cell density was observed compared to broth at all conditions. However, the effects of decreasing pH and a(w) were less pronounced. A further increase in gelatin concentration to 5% gelatin caused a small or no additional drop of growth rate. The final oxygen concentration dropped from 5.5 ppm in stirred broth to anoxic values in petri plates, also when 0% and 5% gelatin media were tested in this recipient. Probably, not stirring the medium, which leads to anoxic conditions, has a more pronounced effect on the growth rate of S. Typhimurium then medium solidness. Finally, growth data were fitted with the primary model of Baranyi and Roberts [Baranyi, J. and Roberts, T. A., 1994. A dynamic approach to predicting bacterial growth in food. International Journal of Food Microbiology 23, 277-294]. An additional factor was introduced into the secondary model of Ross et al. [Ross, T. and Ratkowsky, D. A. and Mellefont, L. A. and McMeekin, T. A., 2003. Modelling the effects of temperature, water activity, pH and lactic acid concentration on the growth rate of Escherichia coli. International Journal of Food Microbiology 82, 33-43.] to incorporate the effect of gelatin concentration, next to the effect of pH and a(w). A two step and a global regression procedure were applied. Both procedures were able to fit the data well, but the global regression procedure led to smaller standard errors on the parameters.

Integration of bio-inspired, control-based visual and olfactory data for the detection of an elusive target

NASA Astrophysics Data System (ADS)

Duong, Tuan A.; Duong, Nghi; Le, Duong

2017-01-01

In this paper, we present an integration technique using a bio-inspired, control-based visual and olfactory receptor system to search for elusive targets in practical environments where the targets cannot be seen obviously by either sensory data. Bio-inspired Visual System is based on a modeling of extended visual pathway which consists of saccadic eye movements and visual pathway (vertebrate retina, lateral geniculate nucleus and visual cortex) to enable powerful target detections of noisy, partial, incomplete visual data. Olfactory receptor algorithm, namely spatial invariant independent component analysis, that was developed based on data of old factory receptor-electronic nose (enose) of Caltech, is adopted to enable the odorant target detection in an unknown environment. The integration of two systems is a vital approach and sets up a cornerstone for effective and low-cost of miniaturized UAVs or fly robots for future DOD and NASA missions, as well as for security systems in Internet of Things environments.

An evolution based biosensor receptor DNA sequence generation algorithm.

PubMed

Kim, Eungyeong; Lee, Malrey; Gatton, Thomas M; Lee, Jaewan; Zang, Yupeng

2010-01-01

A biosensor is composed of a bioreceptor, an associated recognition molecule, and a signal transducer that can selectively detect target substances for analysis. DNA based biosensors utilize receptor molecules that allow hybridization with the target analyte. However, most DNA biosensor research uses oligonucleotides as the target analytes and does not address the potential problems of real samples. The identification of recognition molecules suitable for real target analyte samples is an important step towards further development of DNA biosensors. This study examines the characteristics of DNA used as bioreceptors and proposes a hybrid evolution-based DNA sequence generating algorithm, based on DNA computing, to identify suitable DNA bioreceptor recognition molecules for stable hybridization with real target substances. The Traveling Salesman Problem (TSP) approach is applied in the proposed algorithm to evaluate the safety and fitness of the generated DNA sequences. This approach improves efficiency and stability for enhanced and variable-length DNA sequence generation and allows extension to generation of variable-length DNA sequences with diverse receptor recognition requirements.

Targeted Antiepidermal Growth Factor Receptor (Cetuximab) Immunoliposomes Enhance Cellular Uptake In Vitro and Exhibit Increased Accumulation in an Intracranial Model of Glioblastoma Multiforme

PubMed Central

Mortensen, Joachim Høg

2013-01-01

Therapeutic advances do not circumvent the devastating fact that the survival rate in glioblastoma multiforme (GBM) is less than 5%. Nanoparticles consisting of liposome-based therapeutics are provided against a variety of cancer types including GBM, but available liposomal formulations are provided without targeting moieties, which increases the dosing demands to reach therapeutic concentrations with risks of side effects. We prepared PEGylated immunoliposomes (ILs) conjugated with anti-human epidermal growth factor receptor (EGFR) antibodies Cetuximab (α-hEGFR-ILs). The affinity of the α-hEGFR-ILs for the EGF receptor was evaluated in vitro using U87 mg and U251 mg cells and in vivo using an intracranial U87 mg xenograft model. The xenograft model was additionally analyzed with respect to permeability to endogenous albumin, tumor size, and vascularization. The in vitro studies revealed significantly higher binding of α-hEGFR-ILs when compared with liposomes conjugated with isotypic nonimmune immunoglobulin. The uptake and internalization of the α-hEGFR-ILs by U87 mg cells were further confirmed by 3D deconvolution analyses. In vivo, the α-hEGFR-ILs accumulated to a higher extent inside the tumor when compared to nonimmune liposomes. The data show that α-hEGFR-ILs significantly enhance the uptake and accumulation of liposomes in this experimental model of GBM suggestive of improved specific nanoparticle-based delivery. PMID:24175095

GPCRs as potential therapeutic targets in preeclampsia

PubMed Central

McGuane, JT; Conrad, KP

2012-01-01

Preeclampsia is an important obstetric complication that arises in 5% of women after the 20th week of gestation, for which there is no specific therapy and no cure. Although much of the recent investigation in this field has focused on soluble forms of the angiogenic membrane receptor tyrosine kinase Flt1 and the transforming growth factor β co-receptor Endoglin, there is significant clinical potential for several GPCR targets and their agonists or antagonists in preeclampsia. In this review, we discuss several of the most promising candidates in this category, including calcitonin receptor-like receptor / receptor activity modifying protein 1 complexes, the angiotensin AT1, 2 and Mas receptors, and the relaxin receptor RXFP1. We also address some of the controversies surrounding the roles and therapeutic potential of these GPCRs and their (ant)agonists in preeclampsia. PMID:23144646

Pharmacogenetics of new analgesics

PubMed Central

Lötsch, Jörn; Geisslinger, Gerd

2011-01-01

Patient phenotypes in pharmacological pain treatment varies between individuals, which could be partly assigned to their genotypes regarding the targets of classical analgesics (OPRM1, PTGS2) or associated signalling pathways (KCNJ6). Translational and genetic research have identified new targets, for which new analgesics are being developed. This addresses voltage-gated sodium, calcium and potassium channels, for which SCN9A, CACNA1B, KCNQ2 and KCNQ3, respectively, are primary gene candidates because they code for the subunits of the respective channels targeted by analgesics currently in clinical development. Mutations in voltage gated transient receptor potential (TRPV) channels are known from genetic pain research and may modulate the effects of analgesics under development targeting TRPV1 or TRPV3. To this add ligand-gated ion channels including nicotinic acetylcholine receptors, ionotropic glutamate-gated receptors and ATP-gated purinergic P2X receptors with most important subunits coded by CHRNA4, GRIN2B and P2RX7. Among G protein coupled receptors, δ-opioid receptors (coded by OPRD1), cannabinoid receptors (CNR1 and CNR2), metabotropic glutamate receptors (mGluR5 coded by GRM5), bradykinin B1 (BDKRB1) and 5-HT1A (HTR1A) receptors are targeted by new analgesic substances. Finally, nerve growth factor (NGFB), its tyrosine kinase receptor (NTRK1) and the fatty acid amide hydrolase (FAAH) have become targets of interest. For most of these genes, functional variants have been associated with neuro-psychiatric disorders and not yet with analgesia. However, research on the genetic modulation of pain has already identified variants in these genes, relative to pain, which may facilitate the pharmacogenetic assessments of new analgesics. The increased number of candidate pharmacogenetic modulators of analgesic actions may open opportunities for the broader clinical implementation of genotyping information. PMID:20942817

Gelatin methacrylamide hydrogel with graphene nanoplatelets for neural cell-laden 3D bioprinting.

PubMed

Wei Zhu; Harris, Brent T; Zhang, Lijie Grace

2016-08-01

Nervous system is extremely complex which leads to rare regrowth of nerves once injury or disease occurs. Advanced 3D bioprinting strategy, which could simultaneously deposit biocompatible materials, cells and supporting components in a layer-by-layer manner, may be a promising solution to address neural damages. Here we presented a printable nano-bioink composed of gelatin methacrylamide (GelMA), neural stem cells, and bioactive graphene nanoplatelets to target nerve tissue regeneration in the assist of stereolithography based 3D bioprinting technique. We found the resultant GelMA hydrogel has a higher compressive modulus with an increase of GelMA concentration. The porous GelMA hydrogel can provide a biocompatible microenvironment for the survival and growth of neural stem cells. The cells encapsulated in the hydrogel presented good cell viability at the low GelMA concentration. Printed neural construct exhibited well-defined architecture and homogenous cell distribution. In addition, neural stem cells showed neuron differentiation and neurites elongation within the printed construct after two weeks of culture. These findings indicate the 3D bioprinted neural construct has great potential for neural tissue regeneration.

Diagnostic nanoparticle targeting of the EGF-receptor in complex biological conditions using single-domain antibodies.

PubMed

Zarschler, K; Prapainop, K; Mahon, E; Rocks, L; Bramini, M; Kelly, P M; Stephan, H; Dawson, K A

2014-06-07

For effective localization of functionalized nanoparticles at diseased tissues such as solid tumours or metastases through biorecognition, appropriate targeting vectors directed against selected tumour biomarkers are a key prerequisite. The diversity of such vector molecules ranges from proteins, including antibodies and fragments thereof, through aptamers and glycans to short peptides and small molecules. Here, we analyse the specific nanoparticle targeting capabilities of two previously suggested peptides (D4 and GE11) and a small camelid single-domain antibody (sdAb), representing potential recognition agents for the epidermal growth factor receptor (EGFR). We investigate specificity by way of receptor RNA silencing techniques and look at increasing complexity in vitro by introducing increasing concentrations of human or bovine serum. Peptides D4 and GE11 proved problematic to employ and conjugation resulted in non-receptor specific uptake into cells. Our results show that sdAb-functionalized particles can effectively target the EGFR, even in more complex bovine and human serum conditions where targeting specificity is largely conserved for increasing serum concentration. In human serum however, an inhibition of overall nanoparticle uptake is observed with increasing protein concentration. For highly affine targeting ligands such as sdAbs, targeting a receptor such as EGFR with low serum competitor abundance, receptor recognition function can still be partially realised in complex conditions. Here, we stress the value of evaluating the targeting efficiency of nanoparticle constructs in realistic biological milieu, prior to more extensive in vivo studies.

Silica-gelatin hybrid sol-gel coatings: a proteomic study with biocompatibility implications.

PubMed

Araújo-Gomes, N; Romero-Gavilán, F; Lara-Sáez, I; Elortza, F; Azkargorta, M; Iloro, I; Martínez-Ibañez, M; Martín de Llano, J J; Gurruchaga, M; Goñi, I; Suay, J; Sánchez-Pérez, A M

2018-05-21

Osseointegration, including the foreign body reaction to biomaterials, is an immune-modulated, multifactorial, and complex healing process in which various cells and mediators are involved. The buildup of the osseointegration process is immunological and inflammation-driven, often triggered by the adsorption of proteins on the surfaces of the biomaterials and complement activation. New strategies for improving osseointegration use coatings as vehicles for osteogenic biomolecules delivery from implants. Natural polymers, such as gelatin, can mimic collagen I and enhance the biocompatibility of a material. In this experimental study, two different base sol-gel formulations and their combination with gelatin, were applied as coatings on sandblasted, acid-etched titanium (SAE-Ti) substrates and their biological potential as osteogenic biomaterials was tested. We examined the proteins adsorbed onto each surface and their in vitro and in vivo effects. In vitro results showed an improvement in cell proliferation and mineralization in gelatin-containing samples. In vivo testing showed the presence of a looser connective tissue layer in those coatings with substantially more complement activation proteins adsorbed, especially those containing gelatin. Vitronectin and FETUA, proteins associated with mineralization process, were significantly more adsorbed in gelatin coatings. This article is protected by copyright. All rights reserved.

Effect of the Addition of a Labile Gelatin Component on the Degradation and Solute Release Kinetics of a Stable PEG Hydrogel

PubMed Central

Waldeck, H.; Kao, W. J.

2013-01-01

Characterization of the degradation mechanisms and resulting products of biodegradable materials is critical in understanding the behavior of the material including solute transport and biological response. Previous mathematical analyses of a semi-interpenetrating network (sIPN) containing both labile gelatin and a stable cross-linked poly(ethylene glycol) (PEG) network found that diffusion-based models alone were unable to explain the release kinetics of solutes from the system. In this study, degradation of the sIPN and its effect on solute release and swelling kinetics were investigated. The kinetics of the primary mode of degradation, gelatin dissolution, was dependent on temperature, preparation methods, PEGdA and gelatin concentration, and the weight ratio between the gelatin and PEG. The gelatin dissolution rate positively correlated with both matrix swelling and the release kinetics of high-molecular-weight model compound, FITC-dextran. Coupled with previous in vitro studies, the kinetics of sIPN degradation provided insights into the time-dependent changes in cellular response including adhesion and protein expression. These results provide a facile guide in material formulation to control the delivery of high-molecular-weight compounds with concomitant modulation of cellular behavior. PMID:21801489

Novel bilayer wound dressing based on electrospun gelatin/keratin nanofibrous mats for skin wound repair.

PubMed

Yao, Chun-Hsu; Lee, Chia-Yu; Huang, Chiung-Hua; Chen, Yueh-Sheng; Chen, Kuo-Yu

2017-10-01

A bilayer membrane (GKU) with a commercial polyurethane wound dressing as an outer layer and electrospun gelatin/keratin nanofibrous mat as an inner layer was fabricated as a novel wound dressing. Scanning electron micrographs showed that gelatin/keratin nanofibers had a uniform morphology and bead-free structure with average fiber diameter of 160.4nm. 3-(4,5-Dimethylthiazolyl)-2,5-diphenyltetrazolium bromide assay using L929 fibroblast cells indicated that the residues released from the gelatin/keratin composite nanofibrous mat accelerated cell proliferation. Cell attachment experiments revealed that adhered cells spread better and migrated deeper into the gelatin/keratin nanofibrous mat than that into the gelatin nanofibrous mat. In animal studies, compared with the bilayer membrane without keratin, gauze and commercial wound dressing, Comfeel®, GKU membrane gave much more number of blood vessels and a greater reduction in wound area at 4days, and better wound repair at 14days with a thicker epidermis and larger number of newly formed hair follicles. GKU membrane, thus, could be a good candidate for wound dressing applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Thiol-ene Michael-type formation of gelatin/poly(ethylene glycol) biomatrices for three-dimensional mesenchymal stromal/stem cell administration to cutaneous wounds

PubMed Central

Xu, Kedi; Cantu, David Antonio; Fu, Yao; Kim, Jaehyup; Zheng, Xiaoxiang; Hematti, Peiman; Kao, W. John

2013-01-01

Mesenchymal stromal/stem cells (MSCs) are considered promising cellular therapeutics in the fields of tissue engineering and regenerative medicine. MSCs secrete high concentrations of immunomodulatory cytokines and growth factors, which exert paracrine effects on infiltrating immune and resident cells of the wound microenvironment that could favorably promote healing after acute injury. However, better spatial delivery and improved retention at the site of injury are two factors that could improve the clinical application of MSCs. In this study, we utilized thiol-ene Michael-type addition for rapid encapsulation of MSCs within a gelatin/poly(ethylene glycol) biomatrix; this biomatrix was also applied as a provisional dressing to full-thickness wounds in Sprague-Dawley rats. The three-way interaction of MSCs, gelatin/poly(ethylene glycol) biomatrices, and host immune cells and adjacent resident cells of the wound microenvironment favorably modulated wound progression and host response. In this model we observed attenuated immune cell infiltration, lack of foreign giant cell (FBGC) formation, accelerated wound closure and re-epithelialization, as well as enhanced neovascularization and granulation tissue formation by 7 days. The MSC-entrapped gelatin/poly(ethylene glycol) biomatrix localized the presentation of MSCs adjacent to the wound microenvironment and thus, mediated early resolution of inflammatory events and facilitated proliferative phases in wound healing. PMID:23811217

Tunable Physical Properties of Ethylcellulose/Gelatin Composite Nanofibers by Electrospinning.

PubMed

Liu, Yuyu; Deng, Lingli; Zhang, Cen; Feng, Fengqin; Zhang, Hui

2018-02-28

In this work, the ethylcellulose/gelatin blends at various weight ratios in water/ethanol/acetic acid solution were electrospun to fabricate nanofibers with tunable physical properties. The solution compatibility was predicted based on Hansen solubility parameters and evaluated by rheological measurements. The physical properties were characterized by scanning electron microscopy, porosity, differential scanning calorimetry, thermogravimetry, Fourier transform infrared spectroscopy, and water contact angle. Results showed that the entangled structures among ethylcellulose and gelatin chains through hydrogen bonds gave rise to a fine morphology of the composite fibers with improved thermal stability. The fibers with higher gelatin ratio (75%), possessed hydrophilic surface (water contact angle of 53.5°), and adequate water uptake ability (1234.14%), while the fibers with higher ethylcellulose proportion (75%) tended to be highly water stable with a hydrophobic surface (water contact angle of 129.7°). This work suggested that the composite ethylcellulose/gelatin nanofibers with tunable physical properties have potentials as materials for bioactive encapsulation, food packaging, and filtration applications.

Effect of gelatinized flour fraction on thermal and rheological properties of wheat-based dough and bread.

PubMed

Carrillo-Navas, H; Guadarrama-Lezama, A Y; Vernon-Carter, E J; García-Díaz, S; Reyes, I; Alvarez-Ramírez, J

2016-11-01

This work considered gelatinized wheat flour fraction with properties similar to hydrocolloid to enhance the strength of dough network by improving water retention and rheological characteristics. The gelatinized (90 °C) fraction of the wheat flour was incorporated in the dough formulation at different levels (5, 10, and 20% w/w). The effects of the gelatinized flour (GF) fraction on the dough rheology and thermal properties were studied. The incorporation of GF induced a moderate increase of dough viscoelasticity and reduced the freezing and melting enthalpies. On the other hand, the changes in bread textural properties brought by incorporation of GF were insignificant, indicating that the gelatinized fraction acted as a binder that enhanced water trapping in the structure. SEM images showed a more heterogeneous crumb microstructure (e.g., gas cells, porous, etc.) bread prepared using GF. Drying kinetics obtained from TGA indicated that the water diffusivity decreased with the incorporation of GF, which suggested that the bread had a compact microstructure.

Enzymatic method for measuring starch gelatinization in dry products in situ

USDA-ARS?s Scientific Manuscript database

An enzymatic method based on hydrolysis of starch by amyloglucosidase and measurement of D-glucose released by glucose oxidase-peroxidase was developed to measure both gelatinized starch and hydrolyzable starch in situ of dried starchy products. Efforts focused on the development of sample handling ...

Preparation of fish skin gelatin-based nanofibers incorporating cinnamaldehyde by solution blow spinning

USDA-ARS?s Scientific Manuscript database

Cinnamaldehyde, a natural preservative that can non-specifically deactivate foodborne pathogens, was successfully incorporated into fish skin gelatin (FSG) solutions and blow spun into uniform nanofibers. The effects of cinnamaldehyde ratios (5-30%, w/w FSG) on physicochemical properties of fiber-fo...

Bacterial Immobilization for Imaging by Atomic Force Microscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allison, David P; Sullivan, Claretta; Mortensen, Ninell P

2011-01-01

AFM is a high-resolution (nm scale) imaging tool that mechanically probes a surface. It has the ability to image cells and biomolecules, in a liquid environment, without the need to chemically treat the sample. In order to accomplish this goal, the sample must sufficiently adhere to the mounting surface to prevent removal by forces exerted by the scanning AFM cantilever tip. In many instances, successful imaging depends on immobilization of the sample to the mounting surface. Optimally, immobilization should be minimally invasive to the sample such that metabolic processes and functional attributes are not compromised. By coating freshly cleaved micamore » surfaces with porcine (pig) gelatin, negatively charged bacteria can be immobilized on the surface and imaged in liquid by AFM. Immobilization of bacterial cells on gelatin-coated mica is most likely due to electrostatic interaction between the negatively charged bacteria and the positively charged gelatin. Several factors can interfere with bacterial immobilization, including chemical constituents of the liquid in which the bacteria are suspended, the incubation time of the bacteria on the gelatin coated mica, surface characteristics of the bacterial strain and the medium in which the bacteria are imaged. Overall, the use of gelatin-coated mica is found to be generally applicable for imaging microbial cells.« less

Non-Covalent Assembly of Targeted Carbon Nanovectors Enables Synergistic Drug and Radiation Cancer Therapy In Vivo

PubMed Central

Sano, Daisuke; Berlin, Jacob M.; Pham, Tam T.; Marcano, Daniela C.; Valdecanas, David R.; Zhou, Ge; Milas, Luka; Myers, Jeffrey N.; Tour, James M.

2012-01-01

Current chemotherapeutics are characterized by efficient tumor cell-killing and severe side effects mostly derived from off target toxicity. Hence targeted delivery of these drugs to tumor cells is actively sought. In an in vitro system, we previously demonstrated that targeted drug delivery to cancer cells overexpressing epidermal growth factor receptor (EGFR+) can be achieved by poly(ethylene glycol)-functionalized carbon nanovectors simply mixed with a drug, paclitaxel, and an antibody that binds to the epidermal growth factor receptor, Cetuximab. This construct is unusual in that all three components are assembled through non-covalent interactions. Here we show that this same construct is effective in vivo, enhancing radiotherapy of EGFR+ tumors. This targeted nanovector system has the potential to be a new therapy for head and neck squamous cell carcinomas, deserving of further preclinical development. PMID:22316245

Synthesis and biological evaluation of new water-soluble photoactive chlorin conjugate for targeted delivery.

PubMed

Otvagin, Vasilii F; Nyuchev, Alexander V; Kuzmina, Natalia S; Grishin, Ivan D; Gavryushin, Andrei E; Romanenko, Yuliya V; Koifman, Oscar I; Belykh, Dmitrii V; Peskova, Nina N; Shilyagina, Natalia Yu; Balalaeva, Irina V; Fedorov, Alexey Yu

2018-01-20

A new water-soluble conjugate, consisting of a chlorin-based photosensitizing part, and a 4-arylaminoquinazoline moiety with high potential affinity to an epidermal growth factor receptors (EGFR) and vascular endothelial growth factor receptors (VEGFR), suitable for photodynamic therapy (PDT), was synthesized starting from methylpheophorbide-a in seven steps. An increased accumulation of this compound in A431 cells with high level of EGFR expression, in comparison with CHO and HeLa cells with low EGFR expression was observed. The prepared conjugate exhibits dark and photoinduced cytotoxicity at micromolar concentrations with IC 50dark /IC 50light ratio of 11-18. In tumor-bearing mice, the conjugate preferentially accumulates in the tumor tissue. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Mitochondrial Gene Therapy: Advances in Mitochondrial Gene Cloning, Plasmid Production, and Nanosystems Targeted to Mitochondria.

PubMed

Coutinho, Eduarda; Batista, Cátia; Sousa, Fani; Queiroz, João; Costa, Diana

2017-03-06

Mitochondrial gene therapy seems to be a valuable and promising strategy to treat mitochondrial disorders. The use of a therapeutic vector based on mitochondrial DNA, along with its affinity to the site of mitochondria, can be considered a powerful tool in the reestablishment of normal mitochondrial function. In line with this and for the first time, we successfully cloned the mitochondrial gene ND1 that was stably maintained in multicopy pCAG-GFP plasmid, which is used to transform E. coli. This mitochondrial-gene-based plasmid was encapsulated into nanoparticles. Furthermore, the functionalization of nanoparticles with polymers, such as cellulose or gelatin, enhances their overall properties and performance for gene therapy. The fluorescence arising from rhodamine nanoparticles in mitochondria and a fluorescence microscopy study show pCAG-GFP-ND1-based nanoparticles' cell internalization and mitochondria targeting. The quantification of GFP expression strongly supports this finding. This work highlights the viability of gene therapy based on mitochondrial DNA instigating further in vitro research and clinical translation.

Soft, chewable gelatin-based pharmaceutical oral formulations: a technical approach.

PubMed

Dille, Morten J; Hattrem, Magnus N; Draget, Kurt I

2018-06-01

Hard tablets and capsules for oral drug delivery cause problems for people experiencing dysphagia. This work describes the formulation and properties of a gelatin based, self-preserved, and soft chewable tablet as an alternative and novel drug delivery format. Gelatin (8.8-10% in 24.7-29% water) constituted the matrix of the soft, semi-solid tablets. Three different pharmaceuticals (Ibuprofen 10%, Acetaminophen 15%, and Meloxicam 1.5%) were tested in this formulation. Microbial stability was controlled by lowering the water activity with a mixture of sorbitol and xylitol (45.6-55%). Rheological properties were tested applying small strain oscillation measurements. Taste masking of ibuprofen soft-chew tablets was achieved by keeping the ibuprofen insoluble at pH 4.5 and keeping the processing temperature below the crystalline-to-amorphous transition temperature. Soft-chew formulations showed good stability for all three pharmaceuticals (up to 24 months), and the ibuprofen containing formulation exhibited comparable dissolution to a standard oral tablet as well as good microbial stability. The rheological properties of the ibuprofen/gelatin formulation had the fingerprint of a true gelatin gel, albeit higher moduli, and melting temperature. The results suggest that easy-to-swallow and well taste-masked soft chewable tablet formulations with extended shelf life are within reach for several active pharmaceutical ingredients (APIs).

Gelatin/Carboxymethyl chitosan based scaffolds for dermal tissue engineering applications.

PubMed

Agarwal, Tarun; Narayan, Rajan; Maji, Somnath; Behera, Shubhanath; Kulanthaivel, Senthilguru; Maiti, Tapas Kumar; Banerjee, Indranil; Pal, Kunal; Giri, Supratim

2016-12-01

The present study delineates the preparation, characterization and application of gelatin-carboxymethyl chitosan scaffolds for dermal tissue engineering. The effect of carboxymethyl chitosan and gelatin ratio was evaluated for variations in their physico-chemical-biological characteristics and drug release kinetics. The scaffolds were prepared by freeze drying method and characterized by SEM and FTIR. The study revealed that the scaffolds were highly porous with pore size ranging between 90 and 170μm, had high water uptake (400-1100%) and water retention capacity (>300%). The collagenase mediated degradation of the scaffolds was dependent on the amount of gelatin present in the formulation. A slight yet significant variation in their biological characteristics was also observed. All the formulations supported adhesion, spreading, growth and proliferation of 3T3 mouse fibroblasts. The cells seeded on the scaffolds also demonstrated expression of collagen type I, HIF1α and VEGF, providing a clue regarding their growth and proliferation along with potential to support angiogenesis during wound healing. In addition, the scaffolds showed sustained ampicillin and bovine serum albumin release, confirming their suitability as a therapeutic delivery vehicle during wound healing. All together, the results suggest that gelatin-carboxymethyl chitosan based scaffolds could be a suitable matrix for dermal tissue engineering applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Modulation of GITR for cancer immunotherapy

PubMed Central

Schaer, David A; Murphy, Judith T; Wolchok, Jedd D

2012-01-01

Modulation of co-inhibitory and co-stimulatory receptors of the immune system has become a promising new approach for immunotherapy of cancer. With the recent FDA approval of CTLA-4 blockade serving as an important proof of principal, many new targets are now being translated into the clinic. Preclinical research has demonstrated that targeting glucocorticoid-induced tumor necrosis factor (TNF) receptor related gene (GITR), a member of TNF receptor superfamily, by agonist antibodies or natural ligand, can serve as an effective anti-tumor therapy. In this review, we will cover this research and the rationale that has led to initiation of two phase 1 clinical trials targeting GITR as a new immunotherapeutic approach for cancer. PMID:22245556

Mechanical and barrier properties of maize starch-gelatin composite films: effects of amylose content.

PubMed

Wang, Kun; Wang, Wenhang; Ye, Ran; Xiao, Jingdong; Liu, Yaowei; Ding, Junsheng; Zhang, Shaojing; Liu, Anjun

2017-08-01

In order to obtain new reinforcing bio-fillers to improve the physicochemical properties of gelatin-based films, three types of maize starch, waxy maize starch (Ap), normal starch (Ns) and high-amylose starch (Al), were incorporated into gelatin film and the resulting film properties were investigated, focusing on the impact of amylose content. The thickness, opacity and roughness of gelatin film increased depending on the amylose content along with the starch concentration. The effects of the three starches on the mechanical properties of gelatin film were governed by amylose content, starch concentration as well as environmental relative humidity (RH). At 75% RH, the presence of Al and Ns in the gelatin matrix increased the film strength but decreased its elongation, while Ap exhibited an inverse effect. Starch addition decreased the oxygen permeability of the film, with the lowest value at 20% Al and Ns. All starches, notably at 30% content, led to a decrease in the water vapor permeability of the film at 90% RH, especially Ns starch. Furthermore, the starches improved the thermal stability of the film to some extent. Fourier transform infrared spectra indicated that some weak intermolecular interactions such as hydrogen bonding occurred between gelatin and starch. Moreover, a high degree of B-type crystallinity of starch was characterized in Gel-Al film by X-ray diffraction. Tailoring the properties of gelatin film by the incorporation of different types of maize starch provides the potential to extend its applications in edible food packaging. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Protein Turnover Measurements in Human Serum by Serial Immunoaffinity LC-MS/MS.

PubMed

Farrokhi, Vahid; Chen, Xiaoying; Neubert, Hendrik

2018-02-01

The half-life of target proteins is frequently an important parameter in mechanistic pharmacokinetic and pharmacodynamic (PK/PD) modeling of biotherapeutics. Clinical studies for accurate measurement of physiologically relevant protein turnover can reduce the uncertainty in PK/PD model-based predictions, for example, of the therapeutic dose and dosing regimen in first-in-human clinical trials. We used a targeted mass spectrometry work flow based on serial immunoaffinity enrichment ofmultiple human serum proteins from a [5,5,5- 2 H 3 ]-L-leucine tracer pulse-chase study in healthy volunteers. To confirm the reproducibility of turnover measurements from serial immunoaffinity enrichment, multiple aliquots from the same sample set were subjected to protein turnover analysis in varying order. Tracer incorporation was measured by multiple-reaction-monitoring mass spectrometry and target turnover was calculated using a four-compartment pharmacokinetic model. Five proteins of clinical or therapeutic relevance including soluble tumor necrosis factor receptor superfamily member 12A, tissue factor pathway inhibitor, soluble interleukin 1 receptor like 1, soluble mucosal addressin cell adhesion molecule 1, and muscle-specific creatine kinase were sequentially subjected to turnover analysis from the same human serum sample. Calculated half-lives ranged from 5-15 h; however, no tracer incorporation was observed for mucosal addressin cell adhesion molecule 1. The utility of clinical pulse-chase studies to investigate protein turnover can be extended by serial immunoaffinity enrichment of target proteins. Turnover analysis from serum and subsequently from remaining supernatants provided analytical sensitivity and reproducibility for multiple human target proteins in the same sample set, irrespective of the order of analysis. © 2017 American Association for Clinical Chemistry.

Critical biological parameters modulate affinity as a determinant of function in T-cell receptor gene-modified T-cells.

PubMed

Spear, Timothy T; Wang, Yuan; Foley, Kendra C; Murray, David C; Scurti, Gina M; Simms, Patricia E; Garrett-Mayer, Elizabeth; Hellman, Lance M; Baker, Brian M; Nishimura, Michael I

2017-11-01

T-cell receptor (TCR)-pMHC affinity has been generally accepted to be the most important factor dictating antigen recognition in gene-modified T-cells. As such, there is great interest in optimizing TCR-based immunotherapies by enhancing TCR affinity to augment the therapeutic benefit of TCR gene-modified T-cells in cancer patients. However, recent clinical trials using affinity-enhanced TCRs in adoptive cell transfer (ACT) have observed unintended and serious adverse events, including death, attributed to unpredicted off-tumor or off-target cross-reactivity. It is critical to re-evaluate the importance of other biophysical, structural, or cellular factors that drive the reactivity of TCR gene-modified T-cells. Using a model for altered antigen recognition, we determined how TCR-pMHC affinity influenced the reactivity of hepatitis C virus (HCV) TCR gene-modified T-cells against a panel of naturally occurring HCV peptides and HCV-expressing tumor targets. The impact of other factors, such as TCR-pMHC stabilization and signaling contributions by the CD8 co-receptor, as well as antigen and TCR density were also evaluated. We found that changes in TCR-pMHC affinity did not always predict or dictate IFNγ release or degranulation by TCR gene-modified T-cells, suggesting that less emphasis might need to be placed on TCR-pMHC affinity as a means of predicting or augmenting the therapeutic potential of TCR gene-modified T-cells used in ACT. A more complete understanding of antigen recognition by gene-modified T-cells and a more rational approach to improve the design and implementation of novel TCR-based immunotherapies is necessary to enhance efficacy and maximize safety in patients.

Advances of Molecular Targeted Therapy in Gastric Cancer.

PubMed

Cetin, Bulent; Gumusay, Ozge; Cengiz, Mustafa; Ozet, Ahmet

2016-06-01

Gastric cancer is the second most common cause of cancer-related death in the world, and its prognosis remains poor with a median overall survival of 12 months for advanced disease. Advances in the understanding of molecular genetics have led to the development of directed molecular targeted therapy in gastric cancer, leading to improve patient outcomes and quality of life. In the treatment of human epidermal growth factor receptor 2 (HER2)-positive gastric cancer, the addition of trastuzumab significantly improves survival in the first-line setting of therapy. Ramucirumab, an antibody directed against vascular endothelial growth factor receptor 2, significantly improved progression-free and overall survival and has been approved for second-line treatment of gastric cancer. Anti-mesenchymal-epithelial transition (c-MET), mammalian target of rapamycin inhibitors, and polo-like kinase 1 inhibitors are under investigation as a novel therapeutic option for the treatment of gastric cancer. The novel therapies target the key immune checkpoint interaction between a T cell co-inhibitory receptor called programmed death 1 (PD-1) and one of its immunosuppressive ligands, PD-L1. This article reviews molecular targeted therapies in gastric cancer, in light of recent advances.

Neuropeptide Y Y1 receptors meditate targeted delivery of anticancer drug with encapsulated nanoparticles to breast cancer cells with high selectivity and its potential for breast cancer therapy.

PubMed

Li, Juan; Shen, Zheyu; Ma, Xuehua; Ren, Wenzhi; Xiang, Lingchao; Gong, An; Xia, Tian; Guo, Junming; Wu, Aiguo

2015-03-11

By enabling nanoparticle-based drug delivery system to actively target cancer cells with high selectivity, active targeted molecules have attracted great attention in the application of nanoparticles for anticancer drug delivery. However, the clinical application of most active targeted molecules in breast cancer therapy is limited, due to the low expression of their receptors in breast tumors or coexpression in the normal and tumor breast tissues. Here, a neuropeptide Y Y1 receptors ligand PNBL-NPY, as a novel targeted molecule, is conjugated with anticancer drug doxorubicin encapsulating albumin nanoparticles to investigate the effect of Y1 receptors on the delivery of drug-loaded nanoparticles to breast cancer cells and its potential for breast cancer therapy. The PNBL-NPY can actively recognize and bind to the Y1 receptors that are significantly overexpressed on the surface of the breast cancer cells, and the drug-loaded nanoparticles are delivered directly into the cancer cells through internalization. This system is highly selective and able to distinguish the breast cancer cells from the normal cells, due to normal breast cells that express Y2 receptors only. It is anticipated that this study may provide a guidance in the development of Y1 receptor-based nanoparticulate drug delivery system for a safer and more efficient breast cancer therapy.

Targeted therapies in development for non-small cell lung cancer

PubMed Central

Reungwetwattana, Thanyanan; Dy, Grace Kho

2013-01-01

The iterative discovery in various malignancies during the past decades that a number of aberrant tumorigenic processes and signal transduction pathways are mediated by “druggable” protein kinases has led to a revolutionary change in drug development. In non-small cell lung cancer (NSCLC), the ErbB family of receptors (e.g., EGFR [epidermal growth factor receptor], HER2 [human epidermal growth factor receptor 2]), RAS (rat sarcoma gene), BRAF (v-raf murine sarcoma viral oncogene homolog B1), MAPK (mitogen-activated protein kinase) c-MET (c-mesenchymal-epithelial transition), FGFR (fibroblast growth factor receptor), DDR2 (discoidin domain receptor 2), PIK3CA (phosphatidylinositol-4,5-bisphosphate3-kinase, catalytic subunit alpha)), PTEN (phosphatase and tensin homolog), AKT (protein kinase B), ALK (anaplastic lym phoma kinase), RET (rearranged during transfection), ROS1 (reactive oxygen species 1) and EPH (erythropoietin-producing hepatoma) are key targets of various agents currently in clinical development. These oncogenic targets exert their selective growth advantage through various intercommunicating pathways, such as through RAS/RAF/MEK, phosphoinositide 3-kinase/AKT/mammalian target of rapamycin and SRC-signal transduction and transcription signaling. The recent clinical studies, EGFR tyrosine kinase inhibitors and crizotinib were considered as strongly effective targeted therapies in metastatic NSCLC. Currently, five molecular targeted agents were approved for treatment of advanced NSCLC: Gefitinib, erlotinib and afatinib for positive EGFR mutation, crizotinib for positive echinoderm microtubule-associated protein-like 4 (EML4)-ALK translocation and bevacizumab. Moreover, oncogenic mutant proteins are subject to regulation by protein trafficking pathways, specifically through the heat shock protein 90 system. Drug combinations affecting various nodes in these signaling and intracellular processes are predicted and demonstrated to be synergistic and advantageous in overcoming treatment resistance compared with monotherapy approaches. Understanding the role of the tumor microenvironment in the development and maintenance of the malignant phenotype provided additional therapeutic approaches as well. More recently, improved knowledge on tumor immunology has set the stage for promising immunotherapies in NSCLC. This review will focus on the rationale for the development of targeted therapies in NSCLC and the various strategies employed in preventing or overcoming the inevitable occurrence of treatment resistance. PMID:24574860

Genomic profiling in a homogeneous molecular subtype of non-small cell lung cancer: An effort to explore new drug targets.

PubMed

Veldore, Vidya H; Patil, S; Satheesh, C T; Shashidhara, H P; Tejaswi, R; Prabhudesai, Shilpa A; Krishnamoorthy, N; Hazarika, D; Naik, R; Rao, Raghavendra M; Ajai Kumar, B S

2015-01-01

Patients' who are positive for kinase domain activating mutations in epidermal growth factor receptor (EGFR) gene, constitute 30-40% of non-small cell lung cancer (NSCLC), and are suitable candidates for Tyrosine Kinase Inhibitor based targeted/personalized therapy. In EGFR non-mutated subset, 8-10% that show molecular abnormalities such as EML4-ALK, ROS1-ALK, KIP4-ALK, may also derive the benefit of targeted therapy. However, 40% of NSCLC belong to a grey zone of tumours that are negative for the clinically approved biomarkers for personalized therapy. This pilot study aims to identify and classify molecular subtypes of this group to address the un-met need for new drug targets in this category. Here we screened for known/novel oncogenic driver mutations using a 46 gene Ampliseq Panel V1.0 that includes Ser/Thr/Tyr kinases, transcription factors and tumor suppressors. NSCLC with tumor burden of at least 40% on histopathology were screened for 29 somatic mutations in the EGFR kinase domain by real-time polymerase chain reaction methods. 20 cases which were EGFR non-mutated for TK domain mutations were included in this study. DNA Quality was verified from each of the 20 cases by fluorimeter, pooled and subjected to targeted re-sequencing in the Ion Torrent platform. Torrent Suite software was used for next generation sequencing raw data processing and variant calling. The clinical relevance and pathological role of all the mutations/variants that include SNPs and Indels was assessed using polyphen-2/SIFT/PROVEAN/mutation assessor structure function prediction programs. There were 10 pathogenic mutations in six different oncogenes for which annotation was available in the COSMIC database; C420R mutation in PIK3CA, Q472H mutation in vascular endothelial growth factor receptor 2 (VEGFR2) (KDR), C630W and C634R in RET, K367M mutation in fibroblast growth factor receptor 2 (FGFR2), G12C in KRAS and 4 pathogenic mutations in TP53 in the DNA binding domain (E285K, R213L, R175H, V173G). Results suggest, a potential role for PIK3CA, VEGFR2, RET and FGFR2 as therapeutic targets in EGFR non-mutated NSCLC that requires further clinical validation.

Insights into the conformational switching mechanism of the human vascular endothelial growth factor receptor type 2 kinase domain.

PubMed

Chioccioli, Matteo; Marsili, Simone; Bonaccini, Claudia; Procacci, Piero; Gratteri, Paola

2012-02-27

Human vascular endothelial growth factor receptor type 2 (h-VEFGR2) is a receptor tyrosine kinase involved in the angiogenesis process and regarded as an interesting target for the design of anticancer drugs. Its activation/inactivation mechanism is related to conformational changes in its cytoplasmatic kinase domain, involving first among all the αC-helix in N-lobe and the A-loop in C-lobe. Affinity of inhibitors for the active or inactive kinase form could dictate the open or closed conformation of the A-loop, thus making the different conformations of the kinase domain receptor (KDR) domain different drug targets in drug discovery. In this view, a detailed knowledge of the conformational landscape of KDR domain is of central relevance to rationalize the efficiency and selectivity of kinase inhibitors. Here, molecular dynamics simulations were used to gain insight into the conformational switching activity of the KDR domain and to identify intermediate conformations between the two limiting active and inactive conformations. Specific energy barriers have been selectively removed to induce, and hence highlight at the atomistic level, the regulation mechanism of the A-loop opening. The proposed strategy allowed to repeatedly observe the escape of the KDR domain from the DFG-out free energy basin and to identify rare intermediate conformations between the DFG-out and the DFG-in structures to be employed in a structure-based drug discovery process.

Tracking Progesterone Receptor-Mediated Actions in Breast Cancer

PubMed Central

Knutson, Todd P.; Lange, Carol A.

2014-01-01

Ovarian steroid hormones contribute to breast cancer initiation and progression primarily through the actions of their nuclear transcription factors, the estrogen receptor alpha (ERα) and progesterone receptors (PRs). These receptors are important drivers of the luminal A and B subtypes of breast cancer, where estrogen-blocking drugs have been effective endocrine therapies for patients with these tumors. However, many patients do not respond, or become resistant to treatment. When endocrine therapies fail, the luminal subtypes of breast cancer are more difficult to treat because these subtypes are among the most heterogeneous in terms of mutation diversity and gene expression profiles. Recent evidence suggests that progestin and PR actions may be important drivers of luminal breast cancers. Clinical trial data has demonstrated that hormone replacement therapy with progestins drives invasive breast cancer and results in greater mortality. PR transcriptional activity is dependent upon cross-talk with growth factor signaling pathways that alter PR phosphorylation, acetylation, or SUMOylation as mechanisms for regulating PR target gene selection required for increased cell proliferation and survival. Site-specific PR phosphorylation is the primary driver of gene-selective PR transcriptional activity. However, PR phosphorylation and heightened transcriptional activity is coupled to rapid PR protein degradation; the range of active PR detected in tumors is likely to be dynamic. Thus, PR target gene signatures may provide a more accurate means of tracking PR’s contribution to tumor progression rather than standard clinical protein-based (IHC) assays. Further development of antiprogestin therapies should be considered along side antiestrogens and aromatase inhibitors. PMID:24291072

Recent advances in hyaluronic acid-decorated nanocarriers for targeted cancer therapy.

PubMed

Wickens, Jennifer M; Alsaab, Hashem O; Kesharwani, Prashant; Bhise, Ketki; Amin, Mohd Cairul Iqbal Mohd; Tekade, Rakesh Kumar; Gupta, Umesh; Iyer, Arun K

2017-04-01

The cluster-determinant 44 (CD44) receptor has a high affinity for hyaluronic acid (HA) binding and is a desirable receptor for active targeting based on its overexpression in cancer cells compared with normal body cells. The nanocarrier affinity can be increased by conjugating drug-loaded carriers with HA, allowing enhanced cancer cell uptake via the HA-CD44 receptor-mediated endocytosis pathway. In this review, we discuss recent advances in HA-based nanocarriers and micelles for cancer therapy. In vitro and in vivo experiments have repeatedly indicated HA-based nanocarriers to be a target-specific drug and gene delivery platform with great promise for future applications in clinical cancer therapy. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bmal1 is a direct transcriptional target of the orphan nuclear receptor, NR2F1

USDA-ARS?s Scientific Manuscript database

Orphan nuclear receptor NR2F1 (also known as COUP-TFI, Chicken Ovalbumin Upstream Promoter Transcription Factor I) is a highly conserved member of the nuclear receptor superfamily. NR2F1 plays a critical role during embryonic development, particularly in the central and peripheral nervous systems a...

Agonistic Human Monoclonal Antibodies against Death Receptor 4 (DR4) | NCI Technology Transfer Center | TTC

Cancer.gov

The National Cancer Institute is seeking parties interested in licensing human monoclonal antibodies (mAbs) that bind to death receptor 4 ("DR4"). The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and its functional receptors, DR4 and DR5, have been recognized as promising targets for cancer treatment.

Knowledge-Based Methods To Train and Optimize Virtual Screening Ensembles

PubMed Central

2016-01-01

Ensemble docking can be a successful virtual screening technique that addresses the innate conformational heterogeneity of macromolecular drug targets. Yet, lacking a method to identify a subset of conformational states that effectively segregates active and inactive small molecules, ensemble docking may result in the recommendation of a large number of false positives. Here, three knowledge-based methods that construct structural ensembles for virtual screening are presented. Each method selects ensembles by optimizing an objective function calculated using the receiver operating characteristic (ROC) curve: either the area under the ROC curve (AUC) or a ROC enrichment factor (EF). As the number of receptor conformations, N, becomes large, the methods differ in their asymptotic scaling. Given a set of small molecules with known activities and a collection of target conformations, the most resource intense method is guaranteed to find the optimal ensemble but scales as O(2N). A recursive approximation to the optimal solution scales as O(N2), and a more severe approximation leads to a faster method that scales linearly, O(N). The techniques are generally applicable to any system, and we demonstrate their effectiveness on the androgen nuclear hormone receptor (AR), cyclin-dependent kinase 2 (CDK2), and the peroxisome proliferator-activated receptor δ (PPAR-δ) drug targets. Conformations that consisted of a crystal structure and molecular dynamics simulation cluster centroids were used to form AR and CDK2 ensembles. Multiple available crystal structures were used to form PPAR-δ ensembles. For each target, we show that the three methods perform similarly to one another on both the training and test sets. PMID:27097522

Residues remote from the binding pocket control the antagonist selectivity towards the corticotropin-releasing factor receptor-1

NASA Astrophysics Data System (ADS)

Sun, Xianqiang; Cheng, Jianxin; Wang, Xu; Tang, Yun; Ågren, Hans; Tu, Yaoquan

2015-01-01

The corticotropin releasing factors receptor-1 and receptor-2 (CRF1R and CRF2R) are therapeutic targets for treating neurological diseases. Antagonists targeting CRF1R have been developed for the potential treatment of anxiety disorders and alcohol addiction. It has been found that antagonists targeting CRF1R always show high selectivity, although CRF1R and CRF2R share a very high rate of sequence identity. This has inspired us to study the origin of the selectivity of the antagonists. We have therefore built a homology model for CRF2R and carried out unbiased molecular dynamics and well-tempered metadynamics simulations for systems with the antagonist CP-376395 in CRF1R or CRF2R to address this issue. We found that the side chain of Tyr6.63 forms a hydrogen bond with the residue remote from the binding pocket, which allows Tyr6.63 to adopt different conformations in the two receptors and results in the presence or absence of a bottleneck controlling the antagonist binding to or dissociation from the receptors. The rotameric switch of the side chain of Tyr3566.63 allows the breaking down of the bottleneck and is a perquisite for the dissociation of CP-376395 from CRF1R.

Residues remote from the binding pocket control the antagonist selectivity towards the corticotropin-releasing factor receptor-1.

PubMed

Sun, Xianqiang; Cheng, Jianxin; Wang, Xu; Tang, Yun; Ågren, Hans; Tu, Yaoquan

2015-01-28

The corticotropin releasing factors receptor-1 and receptor-2 (CRF1R and CRF2R) are therapeutic targets for treating neurological diseases. Antagonists targeting CRF1R have been developed for the potential treatment of anxiety disorders and alcohol addiction. It has been found that antagonists targeting CRF1R always show high selectivity, although CRF1R and CRF2R share a very high rate of sequence identity. This has inspired us to study the origin of the selectivity of the antagonists. We have therefore built a homology model for CRF2R and carried out unbiased molecular dynamics and well-tempered metadynamics simulations for systems with the antagonist CP-376395 in CRF1R or CRF2R to address this issue. We found that the side chain of Tyr(6.63) forms a hydrogen bond with the residue remote from the binding pocket, which allows Tyr(6.63) to adopt different conformations in the two receptors and results in the presence or absence of a bottleneck controlling the antagonist binding to or dissociation from the receptors. The rotameric switch of the side chain of Tyr356(6.63) allows the breaking down of the bottleneck and is a perquisite for the dissociation of CP-376395 from CRF1R.

TBK1-targeted suppression of TRIF-dependent signaling pathway of Toll-like receptors by 6-shogaol, an active component of ginger.

PubMed

Park, Se-Jeong; Lee, Mi-Young; Son, Bu-Soon; Youn, Hyung-Sun

2009-07-01

Toll-like receptors (TLRs) are primary sensors that detect a wide variety of microbial components involving induction of innate immune responses. After recognition of microbial components, TLRs trigger the activation of myeloid differential factor 88 (MyD88) and Toll-interleukin-1 (IL-1) receptor domain-containing adapter inducing interferon-beta (TRIF)-dependent downstream signaling pathways. 6-Shoagol, an active ingredient of ginger, inhibits the MyD88-dependent signaling pathway by inhibiting inhibitor-kappaB kinase activity. Inhibitor-kappaB kinase is a key kinase in nuclear factor kappaB (NF-kappaB) activation. However, it is not known whether 6-shogaol inhibits the TRIF-dependent signaling pathway. Our goal was to identify the molecular target of 6-shogaol in the TRIF-dependent pathway of TLRs. 6-Shogaol inhibited the activation of interferon-regulatory factor 3 (IRF3) induced by lipopolysaccharide (LPS) and by polyriboinosinic polyribocytidylic acid (poly[I:C]), overexpression of TRIF, TANK-binding kinase1 (TBK1), and IRF3. Furthermore, 6-shogaol inhibited TBK1 activity in vitro. Together, these results suggest that 6-shogaol inhibits the TRIF-dependent signaling pathway of TLRs by targeting TBK1, and, they imply that 6-shogaol can modulate TLR-derived immune/inflammatory target gene expression induced by microbial infection.

Quantum dots targeted to vascular endothelial growth factor receptor 2 as a contrast agent for the detection of colorectal cancer

NASA Astrophysics Data System (ADS)

Carbary-Ganz, Jordan L.; Barton, Jennifer K.; Utzinger, Urs

2014-08-01

We successfully labeled colorectal cancer in vivo using quantum dots targeted to vascular endothelial growth factor receptor 2 (VEGFR2). Quantum dots with emission centered at 655 nm were bioconjugated to anti-VEGFR2 antibodies through streptavidin/biotin linking. The resulting QD655-VEGFR2 contrast agent was applied in vivo to the colon of azoxymethane (AOM) treated mice via lavage and allowed to incubate. The colons were then excised, cut longitudinally, opened to expose the lumen, and imaged en face using a fluorescence stereoscope. The QD655-VEGFR2 contrast agent produced a significant increase in contrast between diseased and undiseased tissues, allowing for fluorescence-based visualization of the diseased areas of the colon. Specificity was assessed by observing insignificant contrast increase when labeling colons of AOM-treated mice with quantum dots bioconjugated to isotype control antibodies, and by labeling the colons of saline-treated control mice. This contrast agent has a great potential for in vivo imaging of the colon through endoscopy.

Leptin, An Adipokine With Central Importance in the Global Obesity Problem.

PubMed

Mechanick, Jeffrey I; Zhao, Shan; Garvey, W Timothy

2017-12-13

Leptin has central importance in the global obesity and cardiovascular disease problem. Leptin is principally secreted by adipocytes and acts in the hypothalamus to suppress appetite and food intake, increase energy expenditure, and regulate body weight. Based on clinical translation of specific and networked actions, leptin affects the cardiovascular system and may be a marker and driver of cardiometabolic risk factors with interventions that are actionable by cardiologists. Leptin subnetwork analysis demonstrates a statistically significant role for ethnoculturally and socioeconomically appropriate lifestyle intervention in cardiovascular disease. Emergent mechanistic components and potential diagnostic or therapeutic targets include hexokinase 3, urocortins, clusterin, sialic acid-binding immunoglobulin-like lectin 6, C-reactive protein, platelet glycoprotein VI, albumin, pentraxin 3, ghrelin, obestatin prepropeptide, leptin receptor, neuropeptide Y, and corticotropin-releasing factor receptor 1. Emergent associated symptoms include weight change, eating disorders, vascular necrosis, chronic fatigue, and chest pain. Leptin-targeted therapies are reported for lipodystrophy and leptin deficiency, but they are investigational for leptin resistance, obesity, and other chronic diseases. Copyright © 2017 World Heart Federation (Geneva). Published by Elsevier B.V. All rights reserved.

Fibroblast Growth Factor Receptors: From the Oncogenic Pathway to Targeted Therapy.

PubMed

Saichaemchan, S; Ariyawutyakorn, W; Varella-Garcia, M

2016-01-01

The family of fibroblast growth factor (FGFs) and their receptors (FGFRs) regulates vital roles in many biological processes affecting cell proliferation, migration, differentiation and survival. Deregulation of the FGF/FGFR signaling pathway in cancers has been better understood and the main molecular mechanisms responsible for the activation of this pathway are gene mutations, gene fusions and gene amplification. DNA and RNA-based technologies have been used to detect these abnormalities, especially in FGFR1, FGFR2 and FGFR3 and tests have been developed for their detection, but no assay has been proved ideal for molecular diagnosis. Interestingly, the increase in the molecular biology knowledge has supported and assisted the development of therapeutic drugs targeting the most important components of this pathway. Multi- and selective tyrosine kinase inhibitors (TKIs) as well as monoclonal antibodies anti-FGFR are under investigation in preclinical and clinical trials. In this article, we reviewed those aspects with special emphasis on the pathway genomic alterations related to solid tumors, and the molecular diagnostic assays potentially able to stratify patients for the treatment with FGFR TKIs.

Conformational Transition Pathways of Epidermal Growth Factor Receptor Kinase Domain from Multiple Molecular Dynamics Simulations and Bayesian Clustering.

PubMed

Li, Yan; Li, Xiang; Ma, Weiya; Dong, Zigang

2014-08-12

The epidermal growth factor receptor (EGFR) is aberrantly activated in various cancer cells and an important target for cancer treatment. Deep understanding of EGFR conformational changes between the active and inactive states is of pharmaceutical interest. Here we present a strategy combining multiply targeted molecular dynamics simulations, unbiased molecular dynamics simulations, and Bayesian clustering to investigate transition pathways during the activation/inactivation process of EGFR kinase domain. Two distinct pathways between the active and inactive forms are designed, explored, and compared. Based on Bayesian clustering and rough two-dimensional free energy surfaces, the energy-favorable pathway is recognized, though DFG-flip happens in both pathways. In addition, another pathway with different intermediate states appears in our simulations. Comparison of distinct pathways also indicates that disruption of the Lys745-Glu762 interaction is critically important in DFG-flip while movement of the A-loop significantly facilitates the conformational change. Our simulations yield new insights into EGFR conformational transitions. Moreover, our results verify that this approach is valid and efficient in sampling of protein conformational changes and comparison of distinct pathways.

Using 3D Super-Resolution Microscopy to Probe Breast Cancer Stem Cells and Their Microenvironment

DTIC Science & Technology

2014-05-01

cultured on gelatin substrates. This imaging was the first of its kind for breast cancer. We also small controllable microenvironments, in which we can...pyruvate at 37 °C and 5% CO2. Cleaned coverslips were coated with gelatin attachment factor from Invitrogen and incubated at room temperature for 2 hours...or 37C for 30-45 min, and washed with media. The MCF7 cells were dissociated from their culture plate using enzyme-free dissociation buffer from

Hypoxia-inducing factors as master regulators of stemness properties and altered metabolism of cancer- and metastasis-initiating cells

PubMed Central

Mimeault, Murielle; Batra, Surinder K

2013-01-01

Accumulating lines of experimental evidence have revealed that hypoxia-inducible factors, HIF-1α and HIF-2α, are key regulators of the adaptation of cancer- and metastasis-initiating cells and their differentiated progenies to oxygen and nutrient deprivation during cancer progression under normoxic and hypoxic conditions. Particularly, the sustained stimulation of epidermal growth factor receptor (EGFR), insulin-like growth factor-1 receptor (IGF-1R), stem cell factor (SCF) receptor KIT, transforming growth factor-β receptors (TGF-βRs) and Notch and their downstream signalling elements such as phosphatidylinositol 3′-kinase (PI3K)/Akt/molecular target of rapamycin (mTOR) may lead to an enhanced activity of HIFs. Moreover, the up-regulation of HIFs in cancer cells may also occur in the hypoxic intratumoral regions formed within primary and secondary neoplasms as well as in leukaemic cells and metastatic prostate and breast cancer cells homing in the hypoxic endosteal niche of bone marrow. The activated HIFs may induce the expression of numerous gene products such as induced pluripotency-associated transcription factors (Oct-3/4, Nanog and Sox-2), glycolysis- and epithelial-mesenchymal transition (EMT) programme-associated molecules, including CXC chemokine receptor 4 (CXCR4), snail and twist, microRNAs and angiogenic factors such as vascular endothelial growth factor (VEGF). These gene products in turn can play critical roles for high self-renewal ability, survival, altered energy metabolism, invasion and metastases of cancer cells, angiogenic switch and treatment resistance. Consequently, the targeting of HIF signalling network and altered metabolic pathways represents new promising strategies to eradicate the total mass of cancer cells and improve the efficacy of current therapies against aggressive and metastatic cancers and prevent disease relapse. PMID:23301832

Genomic aberrations in the FGFR pathway: opportunities for targeted therapies in solid tumors

PubMed Central

Dienstmann, R.; Rodon, J.; Prat, A.; Perez-Garcia, J.; Adamo, B.; Felip, E.; Cortes, J.; Iafrate, A. J.; Nuciforo, P.; Tabernero, J.

2014-01-01

The fibroblast growth factor receptor (FGFR) cascade plays crucial roles in tumor cell proliferation, angiogenesis, migration and survival. Accumulating evidence suggests that in some tumor types, FGFRs are bona fide oncogenes to which cancer cells are addicted. Because FGFR inhibition can reduce proliferation and induce cell death in a variety of in vitro and in vivo tumor models harboring FGFR aberrations, a growing number of research groups have selected FGFRs as targets for anticancer drug development. Multikinase FGFR/vascular endothelial growth factor receptor (VEGFR) inhibitors have shown promising activity in breast cancer patients with FGFR1 and/or FGF3 amplification. Early clinical trials with selective FGFR inhibitors, which may overcome the toxicity constraints raised by multitarget kinase inhibition, are recruiting patients with known FGFR(1–4) status based on genomic screens. Preliminary signs of antitumor activity have been demonstrated in some tumor types, including squamous cell lung carcinomas. Rational combination of targeted therapies is expected to further increase the efficacy of selective FGFR inhibitors. Herein, we discuss unsolved questions in the clinical development of these agents and suggest guidelines for management of hyperphosphatemia, a class-specific mechanism-based toxicity. In addition, we propose standardized definitions for FGFR1 and FGFR2 gene amplification based on in situ hybridization methods. Extended access to next-generation sequencing platforms will facilitate the identification of diseases in which somatic FGFR(1–4) mutations, amplifications and fusions are potentially driving cancer cell viability, further strengthening the role of FGFR signaling in cancer biology and providing more possibilities for the therapeutic application of FGFR inhibitors. PMID:24265351

Corticosteroid receptors adopt distinct cyclical transcriptional signatures.

PubMed

Le Billan, Florian; Amazit, Larbi; Bleakley, Kevin; Xue, Qiong-Yao; Pussard, Eric; Lhadj, Christophe; Kolkhof, Peter; Viengchareun, Say; Fagart, Jérôme; Lombès, Marc

2018-05-07

Mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs) are two closely related hormone-activated transcription factors that regulate major pathophysiologic functions. High homology between these receptors accounts for the crossbinding of their corresponding ligands, MR being activated by both aldosterone and cortisol and GR essentially activated by cortisol. Their coexpression and ability to bind similar DNA motifs highlight the need to investigate their respective contributions to overall corticosteroid signaling. Here, we decipher the transcriptional regulatory mechanisms that underlie selective effects of MRs and GRs on shared genomic targets in a human renal cellular model. Kinetic, serial, and sequential chromatin immunoprecipitation approaches were performed on the period circadian protein 1 ( PER1) target gene, providing evidence that both receptors dynamically and cyclically interact at the same target promoter in a specific and distinct transcriptional signature. During this process, both receptors regulate PER1 gene by binding as homo- or heterodimers to the same promoter region. Our results suggest a novel level of MR-GR target gene regulation, which should be considered for a better and integrated understanding of corticosteroid-related pathophysiology.-Le Billan, F., Amazit, L., Bleakley, K., Xue, Q.-Y., Pussard, E., Lhadj, C., Kolkhof, P., Viengchareun, S., Fagart, J., Lombès, M. Corticosteroid receptors adopt distinct cyclical transcriptional signatures.

Gelatin-specific cellular immune responses persist for more than 3 years after priming with gelatin containing DTaP vaccine.

PubMed

Kumagai, T; Kamada, M; Igarashi, C; Yuri, K; Furukawa, H; Nagata, N; Saito, A; Okui, T; Yano, S

2002-10-01

Gelatin-specific cell-mediated immunity develops in subjects inoculated with gelatin containing DTaP vaccine. However, it is not yet known whether such established sensitization to gelatin disappears or persists with time. The aim of this study was to follow the patients with gelatin sensitization elicited by DTaP vaccination for their lymphocyte responsiveness and IgE, IgG antibody specific to gelatin over several years and to compare the activities with those at the time of enrollment into the study. We studied 28 subjects who developed positive lymphocyte proliferation test (LPT) after receiving gelatin containing DTaP vaccine and eight subjects who had a negative LPT after inoculation of non-gelatin DTaP. Determination of IgE, IgG antibodies and specific lymphoproliferative response directed against gelatin were performed at enrollment and on follow up. None of the subjects had antibody to gelatin at enrollment and none developed gelatin IgE or IgG during follow-up. There was no significant difference in the SIs of the subjects receiving gelatin DTaP (P = 0.150, 95% CI, -0.198-0.032), whereas lymphocyte activity to gelatin increased between enrollment and follow-up in the subjects with non-gelatin DTaP (P = 0.011, 95% CI, 0.063-0.338). Gelatin-specific lymphocyte activity persists at comparable levels for more than 3 years in subjects who acquire a positive LPT response to gelatin after receiving primary DTaP vaccine containing gelatin. Furthermore, five out of eight subjects initially with negative LPT to gelatin have been shown to acquire specific LPT with time.

[Homeostasis and Disorder of Musculoskeletal System.Diagnosis and Treatment of Congenital Musculoskeletal Diseases.

PubMed

Michigami, Toshimi

Congenital skeletal dysplasias have been considered to be fundamentally untreatable diseases. However, molecular diagnosis by genetic testing has become more prevalent, and efforts are being made to develop novel therapies based on the pathogenesis. As treatments for osteogenesis imperfecta, in addition to anti-resorptive agents, neutralizing antibodies against sclerostin and transforming growth factor(TGF)-β and chemical chaperones can be beneficial. Enzyme replacement therapy using bone-targeting recombinant alkaline phosphatase has been recently developed to treat hypophosphatasia and has much improved the prognosis of the patients affected with severe forms of the disease. To treat the severe short stature in achondroplasia, drugs targeting the fibroblast growth factor receptor 3(FGFR3)-mediated signal are in development for clinical use.

A bi-functional antibody-receptor domain fusion protein simultaneously targeting IGF-IR and VEGF for degradation

PubMed Central

Shen, Yang; Zeng, Lin; Novosyadlyy, Ruslan; Forest, Amelie; Zhu, Aiping; Korytko, Andrew; Zhang, Haifan; Eastman, Scott W; Topper, Michael; Hindi, Sagit; Covino, Nicole; Persaud, Kris; Kang, Yun; Burtrum, Douglas; Surguladze, David; Prewett, Marie; Chintharlapalli, Sudhakar; Wroblewski, Victor J; Shen, Juqun; Balderes, Paul; Zhu, Zhenping; Snavely, Marshall; Ludwig, Dale L

2015-01-01

Bi-specific antibodies (BsAbs), which can simultaneously block 2 tumor targets, have emerged as promising therapeutic alternatives to combinations of individual monoclonal antibodies. Here, we describe the engineering and development of a novel, human bi-functional antibody-receptor domain fusion molecule with ligand capture (bi-AbCap) through the fusion of the domain 2 of human vascular endothelial growth factor receptor 1 (VEGFR1) to an antibody directed against insulin-like growth factor – type I receptor (IGF-IR). The bi-AbCap possesses excellent stability and developability, and is the result of minimal engineering. Beyond potent neutralizing activities against IGF-IR and VEGF, the bi-AbCap is capable of cross-linking VEGF to IGF-IR, leading to co-internalization and degradation of both targets by tumor cells. In multiple mouse xenograft tumor models, the bi-AbCap improves anti-tumor activity over individual monotherapies. More importantly, it exhibits superior inhibition of tumor growth, compared with the combination of anti-IGF-IR and anti-VEGF therapies, via powerful blockade of both direct tumor cell growth and tumor angiogenesis. The unique “capture-for-degradation” mechanism of the bi-AbCap is informative for the design of next-generation bi-functional anti-cancer therapies directed against independent signaling pathways. The bi-AbCap design represents an alternative approach to the creation of dual-targeting antibody fusion molecules by taking advantage of natural receptor-ligand interactions. PMID:26073904

The lymphoproliferative response to enzymatically digested gelatin in subjects with gelatin hypersensitivity.

PubMed

Kumagai, T; Nakayama, T; Kamada, M; Igarashi, C; Yuri, K; Furukawa, H; Wagatuma, K; Tsutsumi, H; Chiba, S; Kojima, H; Saito, A; Okui, T; Yano, S

2000-10-01

This study was designed to evaluate the immunogenic characteristics of enzymatically digested gelatin, 'FreAlagin', employing the lymphoproliferative response in subjects with gelatin hypersensitivity. Our purpose was to assess the response of primed lymphocytes to the newly developed FreAlagin and compare it to the response to conventional gelatin. A gelatin-specific lymphocyte proliferation test (LPT) was performed in 110 children with adverse reactions to gelatin-containing vaccines, who showed positive gelatin-specific cell-mediated immunity and were thus diagnosed as having gelatin hypersensitivity. Gelatin-specific IgE was measured in all subjects. The antigenic activity of FreAlagin to lymphocytes was compared with that of conventional bovine gelatin. Positive and negative control specimens were obtained from the patients with anaphylaxis and from subjects inoculated with gelatin-free vaccine who showed no adverse reactions in order to establish the fluorometric ELISA system to determine IgE antibody to gelatin and LPT. The lymphocyte activity against FreAlagin was much less than that to Wako gelatin and more than half of the subjects who reacted positively to Wako gelatin had a negative LPT to FreAlagin. Although 47% of the subjects had positive LPTs to FreAlagin, all but two still had lower SIs to FreAlagin compared with Wako gelatin. We conclude that the antigenic activity of FreAlagin as measured by the cell-mediated immune response is significantly less than that of conventional bovine gelatin. However, it is still necessary to perform clinical trials to show a reduced or absent clinical reactivity to FreAlagin in sensitized patients to conventional gelatin.

IGF-1 receptor cleavage in hypertension.

PubMed

Cirrik, Selma; Schmid-Schönbein, Geert W

2018-06-01

Increased protease activity causes receptor dysfunction due to extracellular cleavage of different membrane receptors in hypertension. The vasodilatory effects of insulin-like growth factor-1 (IGF-1) are decreased in hypertension. Therefore, in the present study the association of an enhanced protease activity and IGF-1 receptor cleavage was investigated using the spontaneously hypertensive rats (SHRs) and their normotensive Wistar Kyoto (WKY) controls (n = 4). Matrix metalloproteinase (MMP) activities were determined using gelatin zymography on plasma and different tissue samples. WKY aorta rings were incubated in WKY or SHR plasma with or without MMP inhibitors, and immunohistochemistry was used to quantify the densities of the alpha and beta IGF-1 receptor (IGF-1R) subunits and to determine receptor cleavage. The pAkt and peNOS levels in the aorta were investigated using immunoblotting as a measure of IGF-IR function. Increased MMP-2 and MMP-9 activities were detected in plasma and peripheral tissues of SHRs. IGF-1R beta labeling was similar in both groups without plasma incubation, but the fraction of immunolabeled area for IGF-1R alpha was lower in the endothelial layer of the SHR aorta (p < 0.05). A 24-h incubation of WKY aorta with SHR plasma did not affect the IGF-1R beta labeling density, but reduced the IGF-1R alpha labeling density in the endothelium (p < 0.05). MMP inhibitors prevented this decrease (p < 0.01). Western blot analyses revealed that the pAkt and peNOS levels under IGF-1-stimulated and -unstimulated conditions were lower in SHRs (p < 0.05). A reduced IGF-1 cellular response in the aorta was associated with the decrease in the IGF-1R alpha subunit in the SHR hypertension model. Our results indicate that MMP-dependent receptor cleavage contributed to the reduced IGF-1 response in SHRs.

Effect of Target Therapy on the Content of Transcription and Growth Factors, Protein Kinase TOR, and Activity of Intracellular Proteases in Patients with Metastatic Renal Cell Carcinoma.

PubMed

Spirina, L V; Usynin, E A; Kondakova, I V; Yurmazov, Z A; Slonimskaya, E M

2016-04-01

We analyzed the dynamics of the expression of transcription factors, VEGF and its receptor VEGFR2, serine-threonine protein kinase mTOR and activity of proteasome and calpain in patients with metastatic renal cancer during therapy with tyrosine kinase inhibitor Votrient and mTOR blocker Afinitor. The expression of hypoxic nuclear factor HIF-1α in the tumor tissue decreased during therapy with the target preparations. The decrease of VEGF and its receptor VEGFR2 was observed only in patients treated with mTOR inhibitor. The increase in calpain activity in the tumor tissue was observed in both groups. These findings extend our understanding of the mechanism of action of target anticancer preparations as allow considering the studied markers as predictors in choosing optimal therapy.

Experimental Setup to Assess Blast and Penetration-Induced Secondary Debris in a Military Operations in Urban Terrain (MOUT) Environment

DTIC Science & Technology

2015-11-01

Fig. 4 Collection pack with gelatin soap and synthetic gelatin ........................4 Fig. 5 Gelatin soap ...designed to hold 2 synthetic gelatin blocks or a combination of gelatin soap and synthetic gelatin for use as the collection medium (Fig. 4). Shelves...were constructed to support the synthetic gelatin and gelatin soap with dimensions of 25.4 cm wide × 25.4 cm deep. Each shelf was attached to the

Tissue factor activity and ECM-related gene expression in human aortic endothelial cells grown on electrospun biohybrid scaffolds.

PubMed

Han, Jingjia; Gerstenhaber, Jonathan A; Lazarovici, Philip; Lelkes, Peter I

2013-05-13

All blood vessels are lined with a quiescent endothelium, which aids in regulating regular blood flow and avoiding thrombus formation. Current attempts at replacing diseased blood vessels frequently fail due to the intrinsic thrombogenicity of the materials used as vascular grafts. In extending our previous work where we introduced a new candidate scaffolds for vascular grafts electrospun from a blend solution of PLGA, gelatin, and elastin (PGE), this study aimed to evaluate the potential of PGE scaffolds to support nonthrombogenic monolayers of primary isolates of human aortic endothelial cells (HAECs), as assessed by a combination of biochemical, molecular, and bioinformatics-based analyses. After 24 h of culture on 3-D fibrous PGE scaffolds, HAECs formed a confluent, nonthrombogenic, and physiologically competent monolayer, as assessed by tissue factor (TF) gene expression and protein activity assays. The levels of TF mRNA/protein activity in HAECs grown on PGE scaffolds were similar to those on gelatin or collagen IV-coated 2-D surfaces. In addition, bioinformatics-based analysis of a focused microarray containing 84 ECM-related cDNA probes demonstrated that HAECs essentially expressed a histotypic ECM-related "transcriptome" on PGE scaffolds, where cells were more quiescent than cells cultured on 2-D coverslips coated with gelatin (a well-known "inert" substrate for conventional EC culture), but less so than on 2-D PGE films. These data suggest an important role for nanorough substrates (PGE films) in passivating endothelial cells and confirm the crucial effect of substrate composition in this process. Principal component analysis of microarray data on the above substrates (including collagen IV) implied that substrate composition plays a greater role than surface topography in affecting the endothelial ECM-related "transcriptome". Taken together, our findings suggest that electrospun PGE scaffolds are potentially suitable for application in small diameter vascular tissue engineering.

bFGF-containing electrospun gelatin scaffolds with controlled nano-architectural features for directed angiogenesis

PubMed Central

Montero, Ramon B.; Vial, Ximena; Nguyen, Dat Tat; Farhand, Sepehr; Reardon, Mark; Pham, Si M.; Tsechpenakis, Gavriil; Andreopoulos, Fotios M.

2011-01-01

Current therapeutic angiogenesis strategies are focused on the development of biologically responsive scaffolds that can deliver multiple angiogenic cytokines and/or cells in ischemic regions. Herein, we report on a novel electrospinning approach to fabricate cytokine-containing nanofibrous scaffolds with tunable architecture to promote angiogenesis. Fiber diameter and uniformity were controlled by varying the concentration of the polymeric (i.e. gelatin) solution, the feed rate, needle to collector distance, and electric field potential between the collector plate and injection needle. Scaffold fiber orientation (random vs. aligned) was achieved by alternating the polarity of two parallel electrodes placed on the collector plate thus dictating fiber deposition patterns. Basic fibroblast growth factor (bFGF) was physically immobilized within the gelatin scaffolds at variable concentrations and human umbilical vein endothelial cells (HUVEC) were seeded on the top of the scaffolds. Cell proliferation and migration was assessed as a function of growth factor loading and scaffold architecture. HUVECs successfully adhered onto gelatin B scaffolds and cell proliferation was directly proportional to the loading concentrations of the growth factor (0–100 bFGF ng/mL). Fiber orientation had a pronounced effect on cell morphology and orientation. Cells were spread along the fibers of the electrospun scaffolds with the aligned orientation and developed a spindle-like morphology parallel to the scaffold's fibers. In contrast, cells seeded onto the scaffolds with random fiber orientation, did not demonstrate any directionality and appeared to have a rounder shape. Capillary formation (i.e. sprouts length and number of sprouts per bead), assessed in a 3-D in vitro angiogenesis assay, was a function of bFGF loading concentration (0 ng, 50 ng and 100 ng per scaffold) for both types of electrospun scaffolds (i.e. with aligned or random fiber orientation). PMID:22200610

Type 1 receptor tyrosine kinases are differentially phosphorylated in mammary carcinoma and differentially associated with steroid receptors.

PubMed Central

Bacus, S. S.; Chin, D.; Yarden, Y.; Zelnick, C. R.; Stern, D. F.

1996-01-01

The neu/erbB-2/HER-2 proto-oncogene is amplified and/or overexpressed in up to 30% of mammary carcinomas and has been variably correlated with poor prognosis. The signaling activity of the encoded receptor tyrosine kinase is regulated by interactions with other type 1 receptors and their ligands. We have used a novel approach, phosphorylation-sensitive anti-Neu antibodies, to quantify signaling by Neu and epidermal growth factor receptor in a panel of frozen sections of mammary carcinoma specimens. We also determined the relationship of Neu, phosphorylated Neu (and epidermal growth factor receptor), and phosphotyrosine to the expression of Neu-related receptors (epidermal growth factor receptor, HER-3, and HER-4) and to prognostic factors (estrogen and progesterone receptor). We found that tyrosine phosphorylation of Neu (and hence signaling activity) is highly variable among mammary carcinomas. Neu and HER-4 were associated with divergent correlates, suggesting that they have profoundly different biological activities. These results have implications for etiology of mammary carcinoma for clinical evaluation of mammary carcinoma patients, and for development of Neu-targeted therapeutic strategies. Images Figure 1 Figure 2 PMID:8579117

Eco-friendly biorefractory films of gelatin and TEMPO-oxidized cellulose ester for food packaging application.

PubMed

Zhuang, Chen; Tao, Furong; Cui, Yuezhi

2017-08-01

In recent years, many types of food-packaging films and composites have been prepared using gelatin because of its good film-forming ability, non-toxic nature and cost-effectiveness. However, the relatively weak thermal stability, poor mechanical properties and easily-degradable quality limit the potential application of gelatin as a practical material. Microcrystalline cellulose (MCC), which comprises one of the most abundant biomass resources, has been regarded as a safe and reliable food additive because it has the same ingredients as the cellulose in people's daily intake. Food-packaging films with the excellent properties provided by gelatin and oxidized-cellulose represent a topic of great interest. MCC was modified by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation and chosen as the base of the macromolecule cross-linker (TMN). After modification of gelatin film by TMN, the minimum amount of free -NH 2 in solution was 4.8 × 10 -4  mol g -1 ). The thermal property obviously increased (from 322.31  o C to 352.63  o C) and was crucial for usage in the food industry. The highest water contact value 123.09° (η = 25%) indicated a better surface hydrophobicity. The higher E ab (58.88%) and lower E m (77.16%) demonstrated that a more flexible and shatter-proof material was obtained. Water vapor uptake studies suggested increased moisture absorption and greater swelling ability. The film material obtained in the present study was safe, stable, eco-friendly and biorefractory and could also be decomposed completely by the environment after disposal as a result of the properties of the ingredients gelatin and cellulose. The incorporation of a cellulosic cross-linker to gelatin-based films was an ideal choice with respect to developing a packaging for the food industry. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

The emerging role of histology in the choice of first-line treatment of advanced non-small cell lung cancer: implication in the clinical decision-making.

PubMed

Rossi, Antonio; Maione, Paolo; Bareschino, Maria Anna; Schettino, Clorinda; Sacco, Paola Claudia; Ferrara, Marianna Luciana; Castaldo, Vincenzo; Gridelli, Cesare

2010-01-01

Lung cancer is the leading cause of cancer mortality worldwide. Non-small cell lung cancer (NSCLC), accounting for about 85% of all lung cancers, includes squamous carcinoma, adenocarcinoma and undifferentiated large cell carcinoma. The majority of patients have advanced disease at diagnosis, and medical treatment is the cornerstone of management. Several randomized trials comparing third-generation platinum-based doublets concluded that all such combinations are comparable in their clinical efficacy, failing to document a difference based on histology. However, recent evidences, arising from the availability of pemetrexed, have shown that histology represents an important variable in the decision making. The major progresses in the understanding cancer biology and mechanism of oncogenesis have allowed the development of several potential molecular targets for cancer treatment such as vascular growth factor and its receptors and epidermal growth factor receptor. Targeted drugs seem to be safer or more effective in a specific histology subtype. All of these data have led to choose the optimal first-line treatment of advanced NSCLC based on histologic diagnosis. However, this scenario raises a diagnostic issue: a specific diagnosis of NSCLC histologic subtype is mandatory. This review will discuss these new evidences in the first-line treatment of advanced NSCLC and their implication in the current clinical decision-making.

Novel approaches for targeting the adenosine A2A receptor.

PubMed

Yuan, Gengyang; Gedeon, Nicholas G; Jankins, Tanner C; Jones, Graham B

2015-01-01

The adenosine A2A receptor (A2AR) represents a drug target for a wide spectrum of diseases. Approaches for targeting this membrane-bound protein have been greatly advanced by new stabilization techniques. The resulting X-ray crystal structures and subsequent analyses provide deep insight to the A2AR from both static and dynamic perspectives. Application of this, along with other biophysical methods combined with fragment-based drug design (FBDD), has become a standard approach in targeting A2AR. Complementarities of in silico screening based- and biophysical screening assisted- FBDD are likely to feature in future approaches in identifying novel ligands against this key receptor. This review describes evolution of the above approaches for targeting A2AR and highlights key modulators identified. It includes a review of: adenosine receptor structures, homology modeling, X-ray structural analysis, rational drug design, biophysical methods, FBDD and in silico screening. As a drug target, the A2AR is attractive as its function plays a role in a wide spectrum of diseases including oncologic, inflammatory, Parkinson's and cardiovascular diseases. Although traditional approaches such as high-throughput screening and homology model-based virtual screening (VS) have played a role in targeting A2AR, numerous shortcomings have generally restricted their applications to specific ligand families. Using stabilization methods for crystallization, X-ray structures of A2AR have greatly accelerated drug discovery and influenced development of biophysical-in silico hybrid screening methods. Application of these new methods to other ARs and G-protein-coupled receptors is anticipated in the future.

IgE sensitization to gelatin: the probable role of gelatin-containing diphtheria-tetanus-acellular pertussis (DTaP) vaccines.

PubMed

Sakaguchi, M; Inouye, S

2000-04-03

We recently found that most events of anaphylaxis to live attenuated viral vaccines containing gelatin as a stabilizer might be caused by the gelatin. However, the mechanism that the children were sensitized to gelatin was unclear. In Japan, both diphtheria-tetanus-acellular pertussis (DTaP) vaccines with and without gelatin are available. We explored the possibility that gelatin-containing DTaP vaccines before live viral vaccines sensitize children to gelatin. We received the serum samples of 87 children who had systemic immediate-type reactions including anaphylaxis to the vaccines from both physicians and vaccine manufacturers throughout Japan. We then surveyed the DTaP vaccination histories of the children who demonstrated anti-gelatin IgE. Of the above 87 children, 79 (91%) had anti-gelatin IgE. We successfully collected DTaP vaccination histories including the manufacturers' names and numbers of doses on 55 children. Only one child had not received any DTaP vaccine, the other 54 had received gelatin-containing DTaP vaccines and none received gelatin-free DTaP vaccines. We concluded that there was a strong causal relationship between gelatin-containing DTaP vaccination, anti-gelatin IgE production, and risk of anaphylaxis following subsequent immunization with live viral vaccines which contain a larger amount of gelatin.

Gelatin-encapsulated iron oxide nanoparticles for platinum (IV) prodrug delivery, enzyme-stimulated release and MRI.

PubMed

Cheng, Ziyong; Dai, Yunlu; Kang, Xiaojiao; Li, Chunxia; Huang, Shanshan; Lian, Hongzhou; Hou, Zhiyao; Ma, Pingan; Lin, Jun

2014-08-01

A facile method for transferring hydrophobic iron oxide nanoparticles (IONPs) from chloroform to aqueous solution via encapsulation of FITC-modified gelatin based on the hydrophobic-hydrophobic interaction is described in this report. Due to the existence of large amount of active groups such as amine groups in gelatin, the fluorescent labeling molecules of fluorescein isothiocyanate (FITC) and platinum (IV) prodrug functionalized with carboxylic groups can be conveniently conjugated on the IONPs. The nanoparticles carrying Pt(IV) prodrug exhibit good anticancer activities when the Pt(IV) complexes are reduced to Pt(II) in the intracellular environment, while the pure Pt(IV) prodrug only presents lower cytotoxicity on cancer cells. Meanwhile, fluorescence of FITC on the surface of nanoparticles was completely quenched due to the possible Förster Resonance Energy Transfer (FRET) mechanism and showed a fluorescence recovery after gelatin release and detachment from IONPs. Therefore FITC as a fluorescence probe can be used for identification, tracking and monitoring the drug release. In addition, adding pancreatic enzyme can effectively promote the gelatin release from IONPs owing to the degradation of gelatin. Noticeable darkening in magnetic resonance image (MRI) was observed at the tumor site after in situ injection of nanoparticles, indicating the IONPs-enhanced T2-weighted imaging. Our results suggest that the gelatin encapsulated Fe3O4 nanoparticles have potential applications in multi-functional drug delivery system for disease therapy, MR imaging and fluorescence sensor. Copyright © 2014 Elsevier Ltd. All rights reserved.

A novel method for creating custom shaped ballistic gelatin trainers using plaster molds.

PubMed

Doctor, Michael; Katz, Anne; McNamara, Shannon O; Leifer, Jessica H; Bambrick-Santoyo, Gabriela; Saul, Turandot; Rose, Keith M

2018-03-01

Simulation based procedural training is an effective and frequently used method for teaching vascular access techniques which often require commercial trainers. These can be prohibitively expensive, which allows for homemade trainers made of gelatin to be a more cost-effective and attractive option. Previously described trainers are often rectangular with a flat surface that is dissimilar to human anatomy. We describe a novel method to create a more anatomically realistic trainer using ballistic gelatin, household items, and supplies commonly found in an emergency department such as the plaster wrap typically used to make splints.

Structure-based receptor MIMICS targeted against bacterial superantigen toxins

DOEpatents

Gupta, Goutam [Santa Fe, NM; Hong-Geller, Elizabeth [Los Alamos, NM; Shiflett, Patrick R [Los Alamos, NM; Lehnert, Nancy M [Albuquerque, NM

2009-08-18

The invention provides therapeutic compositions useful in the treatment of bacterial superantigen mediated conditions, such as Toxic Shock Syndrome. The compositions comprise genetically engineered bifunctional polypeptides containing a specific T-cell receptor binding domain and a specific MHC class II receptor binding domain, each targeting non-overlapping epitopes on a superantigen molecule against which they are designed. The anti-superantigen "receptor mimetics" or "chimeras" are rationally designed to recreate the modality of superantigen binding directly to both the TCR and the MHC-II receptor, and are capable of acting as decoys for superantigen binding, effectively out-competing the host T-cell and MHC-II receptors, the natural host receptors.

The family B1 GPCR: structural aspects and interaction with accessory proteins.

PubMed

Couvineau, Alain; Laburthe, Marc

2012-01-01

G protein coupled receptors (GPCRs) play a crucial role in physiology and pathophysiology in humans. Beside the large family A (rhodopsin-like receptors) and family C GPCR (metabotropic glutamate receptors), the small family B1 GPCR (secretin-like receptors) includes important receptors such as vasoactive intestinal peptide receptors (VPAC), pituitary adenylyl cyclase activating peptide receptor (PAC1R), secretin receptor (SECR), growth hormone releasing factor receptor (GRFR), glucagon receptor (GCGR), glucagon like-peptide 1 and 2 receptors (GLPR), gastric inhibitory peptide receptor (GIPR), parathyroid hormone receptors (PTHR), calcitonin receptors (CTR) and corticotropin-releasing factor receptors (CRFR). They represent very promising targets for the development of drugs having therapeutical impact on many diseases such as chronic inflammation, neurodegeneration, diabetes, stress and osteoporosis. Over the past decade, structure-function relationship studies have demonstrated that the N-terminal ectodomain (N-ted) of family B1 receptors plays a pivotal role in natural ligand recognition. Structural analysis of some family B1 GPCR N-teds revealed the existence of a Sushi domain fold consisting of two antiparallel β sheets stabilized by three disulfide bonds and a salt bridge. The family B1 GPCRs promote cellular responses through a signaling pathway including predominantly the Gsadenylyl cyclase-cAMP pathway activation. Family B1 GPCRs also interact with a few accessory proteins which play a role in cell signaling, receptor expression and/or pharmacological profiles of receptors. These accessory proteins may represent new targets for the design of new drugs. Here, we review the current knowledge regarding: i) the structure of family B1 GPCR binding domain for natural ligands and ii) the interaction of family B1 GPCRs with accessory proteins.

Differentiated thyroid cancer cell invasion is regulated through epidermal growth factor receptor-dependent activation of matrix metalloproteinase (MMP)-2/gelatinase A

PubMed Central

Yeh, Michael W; Rougier, Jean-Philippe; Park, Jin-Woo; Duh, Quan-Yang; Wong, Mariwil; Werb, Zena; Clark, Orlo H

2008-01-01

Mechanisms of invasion in thyroid cancer remain poorly understood. We hypothesized that signaling via the epidermal growth factor receptor (EGFR) stimulates thyroid cancer cell invasion by altering the expression and cleavage of matrix metalloproteinases (MMPs). Papillary and follicular carcinoma cell lines were treated with EGF, the EGFR tyrosine kinase inhibitor AG1478, and the MMP inhibitors GM-6001 and Col-3. Flow cytometry was used to detect EGFR. In vitro invasion assays, gelatin zymography, and quantitative reverse transcription-PCR were used to assess the changes in invasive behavior and MMP expression and activation. All cell lines were found to overexpress functional EGFR. EGF stimulated invasion by thyroid cancer cells up to sevenfold (P<0.0001), a process that was antagonized completely by AG1478 and Col-3, partially by GM-6001, but not by the serine protease inhibitor aprotinin. EGF upregulated expression of MMP-9 (2.64– to 8.89-fold, P<0.0001) and membrane type-1 MMP (MT1-MMP, 1.97- to 2.67-fold, P<0.0001). This effect was blocked completely by AG1478 and partially by Col-3. The activation of MMP-2 paralleled MT1-MMP expression. We demonstrate that MMPs are critical effectors of invasion in the papillary and follicular thyroid cancer cell lines studied. Invasion is regulated by signaling through EGFR, an effect mediated by augmentation of gelatinase expression and activation. MMP inhibitors and growth factor antagonists may be effective tumoristatic agents for the treatment of aggressive thyroid carcinomas. PMID:17158762

PAMAM (generation 4) incorporated gelatin 3D matrix as an improved dermal substitute for skin tissue engineering.

PubMed

Maji, Somnath; Agarwal, Tarun; Maiti, Tapas Kumar

2017-07-01

The study explored the prospects of PAMAM (generation 4) applicability in gelatin based scaffolds for skin tissue engineering. The effect of PAMAM on physico-chemical and biological characteristics of gelatin scaffolds was evaluated. Gelatin scaffolds (with/without PAMAM) were prepared by lyophilization, chemically crosslinked by glutaraldehyde and characterized for their morphology (pore size), chemical features (bond nature), water adsorption, biodegradation and biological compatibility. The study demonstrated that addition of PAMAM did not significantly alter the pore size distribution or porosity of the scaffolds. However, water adsorption potential and collagenase mediated degradation significantly enhanced over period of the study. Both the scaffolds (with/without PAMAM) were highly biocompatible and hemocompatible. PAMAM (G4) blended scaffolds showed relatively higher cellular adhesion and proliferation of both keratinocytes and fibroblasts with an improved gene expression profile of native collagen type I of fibroblasts. Moreover, expression of angiogenesis inducing genes, HIF1α and VEGF were also higher in PAMAM blended gelatin matrix. Also, PAMAM incorporated gelatin matrix showed a slower rate of drug release which confirms its suitability for therapeutic delivery during wound healing. These results clearly suggest that blending PAMAM (G4) into the matrix could provide an additional support to scaffold assisted wound healing. Copyright © 2017 Elsevier B.V. All rights reserved.

Anaphylaxis from the influenza virus vaccine.

PubMed

Coop, Christopher A; Balanon, Synya K; White, Kevin M; Whisman, Bonnie A; Rathkopf, Melinda M

2008-01-01

Allergic reactions to the influenza vaccine are uncommon and usually associated with sensitivity to egg or gelatin. The aim of this study was to report the case of anaphylaxis to the influenza vaccine. Allergy percutaneous skin testing, serum specific IgE testing and IgE immunoblotting were performed to the influenza vaccine, egg, and gelatin. Percutaneous skin testing to the influenza vaccine and gelatin were positive and egg (white, whole, and yolk) was negative. Immunocap serum-specific IgE testing to egg (white, whole, and yolk) and gelatin were negative (<0.35 kU/l). IgE immunoblots were performed with 2 cord blood serums and the patient's serum at a 1:20 dilution against 10 microg of the Fluzone influenza vaccine. The patient's IgE immunoblot showed a protein band at 100 kDa which is similar to the molecular weight of gelatin protein, a 68-kDa protein which is similar to the molecular weight of hemagglutinin protein from the influenza vaccine, and a 45-kDa protein band that is similar to the molecular weight of ovalbumin protein from chicken embryo/egg. Based on clinical symptoms, skin testing, Immunocap testing and immunoblot evaluation, we feel that our patient is allergic to the infectious agent in the influenza vaccine as well as gelatin and ovalbumin in egg. Copyright 2007 S. Karger AG, Basel.

Laser damage threshold of gelatin and a copper phthalocyanine doped gelatin optical limiter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brant, M.C.; McLean, D.G.; Sutherland, R.L.

1996-12-31

The authors demonstrate optical limiting in a unique guest-host system which uses neither the typical liquid or solid host. Instead, they dope a gelatin gel host with a water soluble Copper (II) phthalocyaninetetrasulfonic acid, tetrasodium salt (CuPcTs). They report on the gelatin`s viscoelasticity, laser damage threshold, and self healing of this damage. The viscoelastic gelatin has mechanical properties quite different than a liquid or solid. The authors` laser measurements demonstrate that the single shot damage threshold of the undoped gelatin host increases with decreasing gelatin concentration. The gelatin also has a much higher laser damage threshold than a stiff acrylic.more » Unlike brittle solids, the soft gelatin self heals from laser induced damage. Optical limiting test also show the utility of a gelatin host doped with CuPcTs. The CuPcTs/gelatin matrix is not damaged at incident laser energies 5 times the single shot damage threshold of the gelatin host. However, at this high laser energy the CuPcTs is photo bleached at the beam waist. The authors repair photo bleached sites by annealing the CuPcTs/gelatin matrix.« less

Use of gelatin gels as a reference material for performance evaluation of meat shear force measurements

USDA-ARS?s Scientific Manuscript database

Establishing standards for meat tenderness based on Warner-Bratzler shear force (WBSF) is complicated by the lack of methods for certifying WBSF testing among texture systems or laboratories. The objective of this study was to determine the suitability of using gelatin gels as a reference material ...

Expression of plasma membrane receptor genes during megakaryocyte development

PubMed Central

Sun, Sijie; Wang, Wenjing; Latchman, Yvette; Gao, Dayong; Aronow, Bruce

2013-01-01

Megakaryocyte (MK) development is critically informed by plasma membrane-localized receptors that integrate a multiplicity of environmental cues. Given that the current understanding about receptors and ligands involved in megakaryocytopoiesis is based on single targets, we performed a genome-wide search to identify a plasma membrane receptome for developing MKs. We identified 40 transmembrane receptor genes as being upregulated during MK development. Seven of the 40 receptor-associated genes were selected to validate the dataset. These genes included: interleukin-9 receptor (IL9R), transforming growth factor, β receptor II (TGFBR2), interleukin-4 receptor (IL4R), colony stimulating factor-2 receptor-beta (CSFR2B), adiponectin receptor (ADIPOR2), thrombin receptor (F2R), and interleukin-21 receptor (IL21R). RNA and protein analyses confirmed their expression in primary human MKs. Matched ligands to IL9R, TGFBR2, IL4R, CSFR2B, and ADIPOR2 affected megakaryocytopoiesis. IL9 was unique in its ability to increase the number of MKs formed. In contrast, MK colony formation was inhibited by adiponectin, TGF-β, IL4, and GM-CSF. The thrombin-F2R axis affected platelet function, but not MK development, while IL21 had no apparent detectable effects. ADP-induced platelet aggregation was suppressed by IL9, TGF-β, IL4, and adiponectin. Overall, six of seven of the plasma membrane receptors were confirmed to have functional roles in MK and platelet biology. Also, results show for the first time that adiponectin plays a regulatory role in MK development. Together these data support a strong likelihood that the 40 transmembrane genes identified as being upregulated during MK development will be an important resource to the research community for deciphering the complex repertoire of environmental cues regulating megakaryocytopoiesis and/or platelet function. PMID:23321270

Design and characteristics of cytotoxic fibroblast growth factor 1 conjugate for fibroblast growth factor receptor-targeted cancer therapy.

PubMed

Szlachcic, Anna; Zakrzewska, Malgorzata; Lobocki, Michal; Jakimowicz, Piotr; Otlewski, Jacek

2016-01-01

Fibroblast growth factor receptors (FGFRs) are attractive candidate cancer therapy targets as they are overexpressed in multiple types of tumors, such as breast, prostate, bladder, and lung cancer. In this study, a natural ligand of FGFR, an engineered variant of fibroblast growth factor 1 (FGF1V), was conjugated to a potent cytotoxic drug, monomethyl auristatin E (MMAE), and used as a targeting agent for cancer cells overexpressing FGFRs, similar to antibodies in antibody-drug conjugates. The FGF1V-valine-citrulline-MMAE conjugate showed a favorable stability profile, bound FGFRs on the cell surface specifically, and efficiently released the drug (MMAE) upon cleavage by the lysosomal protease cathepsin B. Importantly, the conjugate showed a prominent cytotoxic effect toward cell lines expressing FGFR. FGF1V-vcMMAE was highly cytotoxic at concentrations even an order of magnitude lower than those found for free MMAE. This effect was FGFR-specific as cells lacking FGFR did not show any increased mortality.

Design and characteristics of cytotoxic fibroblast growth factor 1 conjugate for fibroblast growth factor receptor-targeted cancer therapy

PubMed Central

Szlachcic, Anna; Zakrzewska, Malgorzata; Lobocki, Michal; Jakimowicz, Piotr; Otlewski, Jacek

2016-01-01

Fibroblast growth factor receptors (FGFRs) are attractive candidate cancer therapy targets as they are overexpressed in multiple types of tumors, such as breast, prostate, bladder, and lung cancer. In this study, a natural ligand of FGFR, an engineered variant of fibroblast growth factor 1 (FGF1V), was conjugated to a potent cytotoxic drug, monomethyl auristatin E (MMAE), and used as a targeting agent for cancer cells overexpressing FGFRs, similar to antibodies in antibody–drug conjugates. The FGF1V–valine–citrulline–MMAE conjugate showed a favorable stability profile, bound FGFRs on the cell surface specifically, and efficiently released the drug (MMAE) upon cleavage by the lysosomal protease cathepsin B. Importantly, the conjugate showed a prominent cytotoxic effect toward cell lines expressing FGFR. FGF1V–vcMMAE was highly cytotoxic at concentrations even an order of magnitude lower than those found for free MMAE. This effect was FGFR-specific as cells lacking FGFR did not show any increased mortality. PMID:27563235

Comparison on mechanical properties of single layered and bilayered chitosan-gelatin coated porous hydroxyapatite scaffold prepared through freeze drying method

NASA Astrophysics Data System (ADS)

Effendi, M. D.; Gustiono, D.; Lukmana; Ayu, D.; Kurniawati, F.

2017-02-01

Biopolymer coated porous hydroxyapatite (HA) scaffolds were prepared for tissue engineering trough freeze drying method and impregnation. in this study, to mimic the mineral and organic component of natural bone, synthetic hydroxapatite (HA) scaffolds coated by polymer were prepared. Highly porous Hap scaffolds, fabricated by synthetic HA impregnation method on polyurethane foam, were coated with polymer coating solution, consisting of chitosan, Gelatin, and bilayered chitosan-gelatin prepared by aging and impregnating technique. For the purpose of comparison, The bare scaffolds without polymer coating layer were investigated. The Bare scaffolds were highly porous and interconnected with a pore size of around 150 µm-714 µm, has porosity at around 67,7% -85,7%, and has mechanical strength at around 0.06 Mpa - 0.071 Mpa, which is suitable for osteoblast cell Proliferation. Chitosan coated porous HA scaffold and gelatin coated porous HA scaffold had mechanical strength at around 0.81-0.85 Mpa, and 1.32-1.34 Mpa, respectively, with weight ratio of biopolymer and Hap was around 18%-22%. To compare these results, the coating on the bare scaffold with gelatin and chitosan had been conducted. Based on the result of FTIR, it could be concluded that coating procedure applied on porous hydroxy apatite (HA) coated by gelatin, chitosan coated HA scaffold, and bilayered Gelatin-chitosan coated porous HA scaffold, confirming that for allsampleshad no significant chemical effect on the coating structure. The compressive strength of bilayered Gelatin-chitosan coated HA scaffold had middle values between the rest, at around 1,06-1.2 Mpa for the samples at the same weight ratio of biopolymer: HA (around 18% - 22%). These results also confirming that coating by gelatin on porous hydroxyapatite was highest compresive strength and can be applied to improve mechanical properties of porous hydroxyapatite bare scaffold

Vitamin E tocotrienols improve insulin sensitivity through activating peroxisome proliferator-activated receptors.

PubMed

Fang, Fang; Kang, Zhanfang; Wong, Chiwai

2010-03-01

Vitamin E is comprised of two classes of compounds: tocopherols and tocotrienols. Tocotrienol-enriched palm oil has been shown to help reduce blood glucose levels in patients and preclinical animal models. However, the mechanistic basis for tocotrienol action is not well established. Peroxisome proliferator-activated receptors alpha, gamma, and delta (PPARalpha, PPARgamma, and PPARdelta) are ligand-regulated transcription factors that play essential roles in energy metabolism. Importantly, synthetic PPARalpha and PPARgamma ligands are currently used for treating hyperlipidemia and diabetes. In this study, we present data that tocotrienols within palm oil functioned as PPAR modulators. Specifically, both alpha- and gamma-tocotrienol activated PPARalpha, while delta-tocotrienol activated PPARalpha, PPARgamma, and PPARdelta in reporter-based assays. Tocotrienols enhanced the interaction between the purified ligand-binding domain of PPARalpha with the receptor-interacting motif of coactivator PPARgamma coactivator-1alpha. In addition, the tocotrienol-rich fraction of palm oil improved whole body glucose utilization and insulin sensitivity of diabetic Db/Db mice by selectively regulating PPAR target genes. These lines of evidence collectively suggested that PPARs represent a set of molecular targets of tocotrienols.

Fibrinogen signal transduction as a mediator and therapeutic target in inflammation: lessons from multiple sclerosis.

PubMed

Adams, R A; Schachtrup, C; Davalos, D; Tsigelny, I; Akassoglou, K

2007-01-01

The blood protein fibrinogen as a ligand for integrin and non-integrin receptors functions as the molecular nexus of coagulation, inflammation and immunity. Studies in animal models and in human disease have demonstrated that extravascular fibrinogen that is deposited in tissues upon vascular rupture is not merely a marker, but a mediator of diseases with an inflammatory component, such as rheumatoid arthritis, multiple sclerosis, sepsis, myocardial infarction and bacterial infection. The present article focuses on the recent discoveries of specific cellular targets and receptors for fibrinogen within tissues that have extended the role of fibrinogen from a coagulation factor to a regulator of inflammation and immunity. Fibrinogen has the potential for selective drug targeting that would target its proinflammatory properties without affecting its beneficial effects in hemostasis, since it interacts with different receptors to mediate blood coagulation and inflammation. Strategies to target receptors for fibrinogen and fibrin within the tissue microenvironment could reveal selective and disease-specific agents for therapeutic intervention in a variety of human diseases associated with fibrin deposition.

Heparin conjugated quantum dots for in vitro imaging applications.

PubMed

Maguire, Ciaran Manus; Mahfoud, Omar Kazem; Rakovich, Tatsiana; Gerard, Valerie Anne; Prina-Mello, Adriele; Gun'ko, Yurii; Volkov, Yuri

2014-11-01

In this work heparin-gelatine multi-layered cadmium telluride quantum dots (QDgel/hep) were synthesised using a novel 'one-pot' method. The QDs produced were characterised using various spectroscopic and physiochemical techniques. Suitable QDs were then selected and compared to thioglycolic acid stabilised quantum dots (QDTGA) and gelatine coated quantum dots (QDgel) for utilisation in in vitro imaging experiments on live and fixed permeabilised THP-1, A549 and Caco-2 cell lines. Exposure of live THP-1 cells to QDgel/hep resulted in localisation of the QDs to the nucleus of the cells. QDgel/hep show affinity for the nuclear compartment of fixed permeabilised THP-1 and A549 cells but remain confined to cytoplasm of fixed permeabilised Caco-2 cells. It is postulated that heparin binding to the CD11b receptor facilitates the internalisation of the QDs into the nucleus of THP-1 cells. In addition, the heparin layer may reduce the unfavourable thrombogenic nature of quantum dots observed in vivo. In this study, heparin conjugated quantum dots were found to have superior imaging properties compared to its native counterparts. The authors postulate that heparin binding to the CD11b receptor facilitates QD internalization to the nucleus, and the heparin layer may reduce the in vivo thrombogenic properties of quantum dots. Copyright © 2014 Elsevier Inc. All rights reserved.

A bioinformatics approach for precision medicine off-label drug drug selection among triple negative breast cancer patients

PubMed Central

Cheng, Lijun; Schneider, Bryan P

2016-01-01

Background Cancer has been extensively characterized on the basis of genomics. The integration of genetic information about cancers with data on how the cancers respond to target based therapy to help to optimum cancer treatment. Objective The increasing usage of sequencing technology in cancer research and clinical practice has enormously advanced our understanding of cancer mechanisms. The cancer precision medicine is becoming a reality. Although off-label drug usage is a common practice in treating cancer, it suffers from the lack of knowledge base for proper cancer drug selections. This eminent need has become even more apparent considering the upcoming genomics data. Methods In this paper, a personalized medicine knowledge base is constructed by integrating various cancer drugs, drug-target database, and knowledge sources for the proper cancer drugs and their target selections. Based on the knowledge base, a bioinformatics approach for cancer drugs selection in precision medicine is developed. It integrates personal molecular profile data, including copy number variation, mutation, and gene expression. Results By analyzing the 85 triple negative breast cancer (TNBC) patient data in the Cancer Genome Altar, we have shown that 71.7% of the TNBC patients have FDA approved drug targets, and 51.7% of the patients have more than one drug target. Sixty-five drug targets are identified as TNBC treatment targets and 85 candidate drugs are recommended. Many existing TNBC candidate targets, such as Poly (ADP-Ribose) Polymerase 1 (PARP1), Cell division protein kinase 6 (CDK6), epidermal growth factor receptor, etc., were identified. On the other hand, we found some additional targets that are not yet fully investigated in the TNBC, such as Gamma-Glutamyl Hydrolase (GGH), Thymidylate Synthetase (TYMS), Protein Tyrosine Kinase 6 (PTK6), Topoisomerase (DNA) I, Mitochondrial (TOP1MT), Smoothened, Frizzled Class Receptor (SMO), etc. Our additional analysis of target and drug selection strategy is also fully supported by the drug screening data on TNBC cell lines in the Cancer Cell Line Encyclopedia. Conclusions The proposed bioinformatics approach lays a foundation for cancer precision medicine. It supplies much needed knowledge base for the off-label cancer drug usage in clinics. PMID:27107440

ErbB receptors in the biology and pathology of the aerodigestive tract

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgan, Sarah; Suite 500, Pittsburgh, PA 15213; Grandis, Jennifer R.

2009-02-15

The most common sites of malignancies in the aerodigestive tract include the lung, head and neck and the esophagus. Esophageal adenocarcinomas (EA), esophageal squamous cell carcinomas (ESCC), and squamous cell carcinomas of the head and neck (SCCHN) are the primary focus of this review. Traditional treatment for aerodigestive tract cancers includes primary chemoradiotherapy (CRT) or surgical resection followed by radiation (or CRT). Recent developments in treatment have focused increasingly on molecular targeting strategies including cetuximab (a monoclonal antibody against epidermal growth factor receptor (EGFR)). Cetuximab was FDA approved in 2006 for treatment of SCCHN, underscoring the importance of understanding themore » biology of these malignancies. EGFR is a member of the ErbB family of growth factor receptor tyrosine kinases. The major pathways activated by ErbB receptors include Ras/Raf/MAPK; PI3K/AKT; PLC{gamma} and STATs, all of which lead to the transcription of target genes that may contribute to aerodigestive tumor progression. This review explores the expression of ErbB receptors in EA, ESCC and SCCHN and the signaling pathways of EGFR in SCCHN.« less

MEK, p38, and PI-3K mediate cross talk between EGFR and TNFR in enhancing hepatocyte growth factor production from human mesenchymal stem cells

PubMed Central

Wang, Yue; Weil, Brent R.; Herrmann, Jeremy L.; Abarbanell, Aaron M.; Tan, Jiangning; Markel, Troy A.; Kelly, Megan L.

2009-01-01

Human bone marrow mesenchymal stem cells (MSCs) are a potent source of growth factors, which are partly responsible for their beneficial paracrine effects. We reported previously that transforming growth factor-α (TGF-α), a putative mediator of wound healing and the injury response, increases the release of vascular endothelial growth factor (VEGF), augments tumor necrosis factor-α (TNF-α)-stimulated VEGF production, and activates mitogen-activated protein kinases and phosphatidylinositol 3-kinase (PI-3K) pathway in human MSCs. The experiments described in this report indicate that TGF-α increases MSC-derived hepatocyte growth factor (HGF) production. TGF-α-stimulated HGF production was abolished by inhibition of MEK, p38, PI-3K, or by small interfering RNA (siRNA) targeting TNF receptor 2 (TNFR2), but was not attenuated by siRNA targeting TNF receptor 1 (TNFR1). Ablation of TNFR1 significantly increased basal and stimulated HGF. A potent synergy between TGF-α and TNF-α was noted in MSC HGF production. This synergistic effect was abolished by MEK, P38, PI-3K inhibition, or by ablation of both TNF receptors using siRNA. We conclude that 1) novel cross talk occurs between tumor necrosis factor receptor and TGF-α/epidermal growth factor receptor in stimulating MSC HGF production; 2) this cross talk is mediated, at least partially, via activation of MEK, p38, and PI-3K; 3) TGF-α stimulates MSCs to produce HGF by MEK, p38, PI-3K, and TNFR2-dependent mechanisms; and 4) TNFR1 acts to decrease basal TGF-α and TNF-α-stimulated HGF. PMID:19692652

EGF receptor-targeting peptide conjugate incorporating a near-IR fluorescent dye and a novel 1,4,7-triazacyclononane-based (64)Cu(II) chelator assembled via click chemistry.

PubMed

Viehweger, Katrin; Barbaro, Lisa; García, Karina Pombo; Joshi, Tanmaya; Geipel, Gerhard; Steinbach, Jörg; Stephan, Holger; Spiccia, Leone; Graham, Bim

2014-05-21

A new Boc-protected 1,4,7-triazacyclononane (TACN)-based pro-chelator compound featuring a "clickable" azidomethylpyridine pendant has been developed as a building block for the construction of multimodal imaging agents. Conjugation to a model alkyne (propargyl alcohol), followed by deprotection, generates a pentadentate ligand, as confirmed by X-ray crystallographic analysis of the corresponding distorted square-pyramidal Cu(II) complex. The ligand exhibits rapid (64)Cu(II)-binding kinetics (>95% radiochemical yield in <5 min) and a high resistance to demetalation. It may thus prove suitable for use in (64)Cu(II)-based in vivo positron emission tomography (PET). The new chelating building block has been applied to the construction of a bimodal (PET/fluorescence) peptide-based imaging probe targeting the epidermal growth factor (EGF) receptor, which is highly overexpressed on the surface of several types of cancer cells. The probe consists of a hexapeptide sequence, Leu-Ala-Arg-Leu-Leu-Thr (designated "D4"), followed by a Cys-β-Ala-β-Ala spacer, then a β-homopropargylglycine residue with the TACN-based chelator "clicked" to its side chain. A sulfonated near-infrared (NIR) fluorescent cyanine dye (sulfo-Cy5) was introduced at the N-terminus to study the EGF receptor-binding ability of the probe by laser-fluorescence spectroscopy. Binding was also confirmed by coimmunoprecipitation methods, and an apparent dissociation constant (Kd) of ca. 10 nM was determined from radioactivity-based measurements of probe binding to two EGF receptor-expressing cell lines (FaDu and A431). The probe is shown to be a biased or partial allosteric agonist of the EGF receptor, inducing phosphorylation of Thr669 and Tyr992, but not the Tyr845, Tyr998, Tyr1045, Tyr1068, or Tyr1148 residues of the receptor, in the absence of the orthosteric EGF ligand. Additionally, the probe was found to suppress the EGF-stimulated autophosphorylation of these latter residues, indicating that it is also a noncompetitive antagonist.

Improvements in soft gelatin capsule sample preparation for USP-based simethicone FTIR analysis.

PubMed

Hargis, Amy D; Whittall, Linda B

2013-02-23

Due to the absence of a significant chromophore, Simethicone raw material and finished product analysis is achieved using a FTIR-based method that quantifies the polydimethylsiloxane (PDMS) component of the active ingredient. The method can be found in the USP monographs for several dosage forms of Simethicone-containing pharmaceutical products. For soft gelatin capsules, the PDMS assay values determined using the procedure described in the USP method were variable (%RSDs from 2 to 9%) and often lower than expected based on raw material values. After investigation, it was determined that the extraction procedure used for sample preparation was causing loss of material to the container walls due to the hydrophobic nature of PDMS. Evaluation revealed that a simple dissolution of the gelatin capsule fill in toluene provided improved assay results (%RSDs≤0.5%) as well as a simplified and rapid sample preparation. Copyright © 2012 Elsevier B.V. All rights reserved.

Gene Therapy Approaches to Human Immunodeficiency Virus and Other Infectious Diseases.

PubMed

Rogers, Geoffrey L; Cannon, Paula M

2017-10-01

Advances in gene therapy technologies, particularly in gene editing, are suggesting new avenues for the treatment of human immunodeficiency virus and other infectious diseases. This article outlines recent developments in antiviral gene therapies, including those based on the disruption of entry receptors or that target viral genomes using targeted nucleases, such as the CRISPR/Cas9 system. In addition, new ways to express circulating antiviral factors, such as antibodies, and approaches to harness and engineer the immune system to provide an antiviral effect that is not naturally achieved are described. Copyright © 2017 Elsevier Inc. All rights reserved.

Erythrocyte-derived optical nano-vesicles as theranostic agents

NASA Astrophysics Data System (ADS)

Mac, Jenny T.; Nunez, Vicente; Bahmani, Baharak; Guerrero, Yadir; Tang, Jack; Vullev, Valentine I.; Anvari, Bahman

2015-07-01

We have engineered nano-vesicles, derived from erythrocytes, which can be doped with various near infrared (NIR) organic chromophores, including the FDA-approved indocyanine green (ICG). We refer to these vesicles as NIR erythrocyte-mimicking transducers (NETS) since in response to NIR photo-excitation they can generate heat or emit fluorescent light. Using biochemical methods based on reduction amination, we have functionalized the surface of NET with antibodies to target specific biomolecules. We present results that demonstrate the effectiveness of NETs in targeted imaging of cancer cells that over-express the human epidermal growth factor receptor-2 (HER2).

Exendin-4 ameliorates oxidized-LDL-induced inhibition of macrophage migration in vitro via the NF-κB pathway

PubMed Central

Ma, Ge-fei; Chen, Song; Yin, Lei; Gao, Xiang-dong; Yao, Wen-bing

2014-01-01

Aim: To investigate the effects of the glucagon-like peptide-1 (GLP-1) receptor agonist exendin-4 on oxidized low-density lipoprotein (ox-LDL)-induced inhibition of macrophage migration and the mechanisms underlying the effects of exendin-4. Methods: Primary peritoneal macrophages were extracted from the peritoneal cavity of mice treated with 3% thioglycollate (2 mL, ip). Migration of the macrophages was examined using a cell migration assay. Macrophage migration-related factors including leptin-like ox-LDL receptor (LOX-1), cyclooxygenase 2 (COX-2), tumor necrosis factor (TNF)-α, interleukin-1 (IL-1)β, matrix metalloproteinase-2 (MMP-2), intercellular adhesion molecule (ICAM)-1 and macrophage migration inhibitory factor (MIF) were measured using semi-quantitative RT-PCR. Expression of MIF and ICAM-1 proteins was examined with ELISA. Gelatin zymography was used to evaluate the activity of MMP-9. Activation of the NF-κB pathway was determined by confocal laser scanning microscopy. Results: Treatment of the macrophages with ox-LDL (50 μg/mL) markedly suppressed the macrophage migration. Furthermore, ox-LDL treatment substantially increased the expression of the macrophage migration-related factors, the activity of MMP-9 and the translocation of the NF-κB p65 subunit. These effects of ox-LDL were significantly ameliorated by pretreatment with the specific NF-κB inhibitor ammonium pyrrolidine dithiocarbamate (100 μmol/L). These effects of ox-LDL were also significantly ameliorated by pretreatment with exendin-4 (25 and 50 nmol/L). Conclusion: Exendin-4 ameliorates the inhibition of ox-LDL on macrophage migration in vitro, via suppressing ox-LDL-induced expression of ICAM-1 and MIF, which is probably mediated by the NF-κB pathway. PMID:24335838

Exendin-4 ameliorates oxidized-LDL-induced inhibition of macrophage migration in vitro via the NF-κB pathway.

PubMed

Ma, Ge-fei; Chen, Song; Yin, Lei; Gao, Xiang-dong; Yao, Wen-bing

2014-02-01

To investigate the effects of the glucagon-like peptide-1 (GLP-1) receptor agonist exendin-4 on oxidized low-density lipoprotein (ox-LDL)-induced inhibition of macrophage migration and the mechanisms underlying the effects of exendin-4. Primary peritoneal macrophages were extracted from the peritoneal cavity of mice treated with 3% thioglycollate (2 mL, ip). Migration of the macrophages was examined using a cell migration assay. Macrophage migration-related factors including leptin-like ox-LDL receptor (LOX-1), cyclooxygenase 2 (COX-2), tumor necrosis factor (TNF)-α, interleukin-1 (IL-1)β, matrix metalloproteinase-2 (MMP-2), intercellular adhesion molecule (ICAM)-1 and macrophage migration inhibitory factor (MIF) were measured using semi-quantitative RT-PCR. Expression of MIF and ICAM-1 proteins was examined with ELISA. Gelatin zymography was used to evaluate the activity of MMP-9. Activation of the NF-κB pathway was determined by confocal laser scanning microscopy. Treatment of the macrophages with ox-LDL (50 μg/mL) markedly suppressed the macrophage migration. Furthermore, ox-LDL treatment substantially increased the expression of the macrophage migration-related factors, the activity of MMP-9 and the translocation of the NF-κB p65 subunit. These effects of ox-LDL were significantly ameliorated by pretreatment with the specific NF-κB inhibitor ammonium pyrrolidine dithiocarbamate (100 μmol/L). These effects of ox-LDL were also significantly ameliorated by pretreatment with exendin-4 (25 and 50 nmol/L). Exendin-4 ameliorates the inhibition of ox-LDL on macrophage migration in vitro, via suppressing ox-LDL-induced expression of ICAM-1 and MIF, which is probably mediated by the NF-κB pathway.

HER2-positive breast cancer, how far away from the cure?-on the current situation of anti-HER2 therapy in breast cancer treatment and survival of patients.

PubMed

Liao, Ning

2016-06-01

With the diagnosis and treatment of tumor enter into the area of precision medical, based on selected targeted molecular typing of patients with individualized diagnosis and treatment play an important role. HER gene encoded epidermal growth factor receptor 2 (HER2) leading to increased early distant metastasis of breast cancer in patients and poor prognosis. However, a number of clinical studies provided evidence-based anti-HER2 targeted therapy and confirmed the benefit of anti-HER2 targeted therapy in patient survival. In recent years, through the tireless efforts of scholars in the field of breast cancer in our country, the whole diagnosis and treatment of breast cancer has accomplished an international standard. But based on a variety of factors, the anti-HER2 targeted therapy between China and the developed countries, and between different areas in China still exists certain gaps, is now a problem need to be solved. This article will analyzing the diagnostic and treatment on HER2-positive breast cancer in the United States and China, exploring reasons and looking for answers to narrow down the gap in the treatment of HER2-positive breast cancer between China and the United States. Improve the anti-HER2 targeted therapy in our country, let the patients get maximum benefit from anti-HER2 targeted therapy.

Microfluidic-based screening of resveratrol and drug-loading PLA/Gelatine nano-scaffold for the repair of cartilage defect.

PubMed

Ming, Li; Zhipeng, Yuan; Fei, Yu; Feng, Rao; Jian, Weng; Baoguo, Jiang; Yongqiang, Wen; Peixun, Zhang

2018-03-26

Cartilage defect is common in clinical but notoriously difficult to treat for low regenerative and migratory capacity of chondrocytes. Biodegradable tissue engineering nano-scaffold with a lot of advantages has been the direction of material to repair cartilage defect in recent years. The objective of our study is to establish a biodegradable drug-loading synthetic polymer (PLA) and biopolymer (Gelatine) composite 3D nano-scaffold to support the treatment of cartilage defect. We designed a microfluidic chip-based drug-screening device to select the optimum concentration of resveratrol, which has strong protective capability for chondrocyte. Then biodegradable resveratrol-loading PLA/Gelatine 3D nano-scaffolds were fabricated and used to repair the cartilage defects. As a result, we successfully cultured primary chondrocytes and screened the appropriate concentrations of resveratrol by the microfluidic device. We also smoothly obtained superior biodegradable resveratrol-loading PLA/Gelatine 3D nano-scaffolds and compared the properties and therapeutic effects of cartilage defect in rats. In summary, our microfluidic device is a simple but efficient platform for drug screening and resveratrol-loading PLA/Gelatine 3D nano-scaffolds could greatly promote the cartilage formation. It would be possible for materials and medical researchers to explore individualized pharmacotherapy and drug-loading synthetic polymer and biopolymer composite tissue engineering scaffolds for the repair of cartilage defect in future.

Extraction and characterization of gelatin from two edible Sudanese insects and its applications in ice cream making.

PubMed

Mariod, Abdalbasit Adam; Fadul, Hadia

2015-07-01

Three methods were used for extraction of gelatin from two insects, melon bug (Coridius viduatus) and sorghum bug (Agonoscelis versicoloratus versicoloratus). Extraction of insect gelatin using hot water gave higher yield reached up to 3.0%, followed by mild acid extraction which gave 1.5% and distilled water extraction which gave only 1.0%, respectively. The obtained gelatins were characterized by FTIR and the spectra of insect's gelatin seem to be similar when compared with commercial gelatin. Amide II bands of gelatins from melon and sorghum bug appeared around at 1542-1537 cm(-1). Slight differences in the amino acid composition of gelatin extracted from the two insects were observed. Ice cream was made by using 0.5% insect's gelatin and compared with that made using 0.5% commercial gelatin as stabilizing agent. The properties of the obtained ice cream produced using insects gelatin were significantly different when compared with that made using commercial gelatin. © The Author(s) 2014.

Fabrication and Physical Evaluation of Gelatin-Coated Carbonate Apatite Foam.

PubMed

Hara, Kanae; Fujisawa, Kenji; Nagai, Hirokazu; Takamaru, Natsumi; Ohe, Go; Tsuru, Kanji; Ishikawa, Kunio; Miyamoto, Youji

2016-08-23

Carbonate apatite (CO₃Ap) foam has gained much attention in recent years because of its ability to rapidly replace bone. However, its mechanical strength is extremely low for clinical use. In this study, to understand the potential of gelatin-reinforced CO₃Ap foam for bone replacement, CO₃Ap foam was reinforced with gelatin and the resulting physical characteristics were evaluated. The mechanical strength increased significantly with the gelatin reinforcement. The compressive strength of gelatin-free CO₃Ap foam was 74 kPa whereas that of the gelatin-reinforced CO₃Ap foam, fabricated using 30 mass % gelatin solution, was approximately 3 MPa. Heat treatment for crosslinking gelatin had little effect on the mechanical strength of the foam. The gelatin-reinforced foam did not maintain its shape when immersed in a saline solution as this promoted swelling of the gelatin; however, in the same conditions, the heat-treated gelatin-reinforced foam proved to be stable. It is concluded, therefore, that heat treatment is the key to the fabrication of stable gelatin-reinforced CO₃Ap foam.

Folate targeted polymeric 'green' nanotherapy for cancer

NASA Astrophysics Data System (ADS)

Narayanan, Sreeja; Binulal, N. S.; Mony, Ullas; Manzoor, Koyakutty; Nair, Shantikumar; Menon, Deepthy

2010-07-01

The concept of 'green' chemotherapy by employing targeted nanoparticle mediated delivery to enhance the efficacy of phytomedicines is reported. Poly (lactide-co-glycolide) (PLGA) nanoparticles encapsulating a well known nutraceutical namely, grape seed extract (GSE)—'NanoGSE'—was prepared by a nanoprecipitation technique. The drug-loaded nanoparticles of size ~ 100 nm exhibited high colloidal stability at physiological pH. Molecular receptor targeting of this nanophytomedicine against folate receptor over-expressing cancers was demonstrated in vitro by conjugation with a potential cancer targeting ligand, folic acid (FA). Fluorescence microscopy and flow cytometry data showed highly specific cellular uptake of FA conjugated NanoGSE on folate receptor positive cancer cells. Studies were also conducted to investigate the efficiency of targeted (FA conjugated) versus non-targeted (non-FA conjugated) nanoformulations in causing cancer cell death. The IC50 values were lowered by a factor of ~ 3 for FA-NanoGSE compared to the free drug, indicating substantially enhanced bioavailability to the tumor cells, sparing the normal ones. Receptor targeting of FA-NanoGSE resulted in a significant increase in apoptotic index, which was also quantified by flow cytometry and fluorescence microscopy. This in vitro study provides a basis for the use of nanoparticle mediated delivery of anticancer nutraceuticals to enhance bioavailability and effectively target cancer by a 'green' approach.

Synergistic apoptosis in head and neck squamous cell carcinoma cells by co-inhibition of insulin-like growth factor-1 receptor signaling and compensatory signaling pathways.

PubMed

Axelrod, Mark J; Mendez, Rolando E; Khalil, Ashraf; Leimgruber, Stephanie S; Sharlow, Elizabeth R; Capaldo, Brian; Conaway, Mark; Gioeli, Daniel G; Weber, Michael J; Jameson, Mark J

2015-12-01

In head and neck squamous cell carcinoma (HNSCC), resistance to single-agent targeted therapy may be overcome by co-targeting of compensatory signaling pathways. A targeted drug screen with 120 combinations was used on 9 HNSCC cell lines. Multiple novel drug combinations demonstrated synergistic growth inhibition. Combining the insulin-like growth factor-1 receptor (IGF-1R) inhibitor, BMS754807, with either the human epidermal growth factor receptor (HER)-family inhibitor, BMS599626, or the Src-family kinase inhibitor, dasatinib, resulted in substantial synergy and growth inhibition. Depending on the cell line, these combinations induced synergistic or additive apoptosis; when synergistic apoptosis was observed, AKT phosphorylation was inhibited to a greater extent than either drug alone. Conversely, when additive apoptosis occurred, AKT phosphorylation was not reduced by the drug combination. Combined IGF-1R/HER family and IGF-1R/Src family inhibition may have therapeutic potential in HNSCC. AKT may be a node of convergence between IGF-1R signaling and pathways that compensate for IGF-1R inhibition. © 2015 Wiley Periodicals, Inc.

Enhanced Sternal Healing via Platelet-Rich Plasma and Biodegradable Gelatin Hydrogel.

PubMed

Shibata, Masafumi; Takagi, Gen; Kudo, Mitsuhiro; Kurita, Jiro; Kawamoto, Yoko; Miyagi, Yasuo; Kanazashi, Mikimoto; Sakatani, Takashi; Naito, Zenya; Tabata, Yasuhiko; Miyamoto, Masaaki; Nitta, Takashi

2018-05-16

Platelet-rich plasma (PRP) contains numerous growth factors and promotes bone fracture healing. The aim of this study was to evaluate the effectiveness of the controlled release of PRP from biodegradable gelatin hydrogel for promoting healing in a rabbit ischemic sternal model. PRP was prepared from the whole blood of a Japanese white rabbit. Sixteen rabbits were randomized into four groups (each n = 4) and all underwent median sternotomy and bilateral internal thoracic artery removal. Before the sternum was closed, the following solutions were applied between the sternum incisions in three of the groups: 30 mg of gelatin hydrogel incorporating 300 μL of phosphate-buffered saline, 300 μL of a solution form of PRP, or 30 mg of gelatin hydrogel incorporating 300 μL of PRP (PRP+Gel). The fourth group acted as a control. Sternal healing was evaluated by histology and micro-computed tomography 7 days after the intervention. The PRP+Gel group showed a significantly higher proportion of fibrosis within the fracture area (an indicator of sternal healing) than the other groups and a significantly higher mean intensity of osteocalcin. These results indicate that the controlled release of PRP from locally applied gelatin hydrogel was markedly effective in enhancing sternal healing in the early postoperative period. This novel therapy could potentially help prevent complications such as deep sternal wound infection and could result in early postoperative ambulation after median sternotomy.

New Strategies in Engineering T-cell Receptor Gene-Modified T cells to More Effectively Target Malignancies.

PubMed

Schmitt, Thomas M; Stromnes, Ingunn M; Chapuis, Aude G; Greenberg, Philip D

2015-12-01

The immune system, T cells in particular, have the ability to target and destroy malignant cells. However, antitumor immune responses induced from the endogenous T-cell repertoire are often insufficient for the eradication of established tumors, as illustrated by the failure of cancer vaccination strategies or checkpoint blockade for most tumors. Genetic modification of T cells to express a defined T-cell receptor (TCR) can provide the means to rapidly generate large numbers of tumor-reactive T cells capable of targeting tumor cells in vivo. However, cell-intrinsic factors as well as immunosuppressive factors in the tumor microenvironment can limit the function of such gene-modified T cells. New strategies currently being developed are refining and enhancing this approach, resulting in cellular therapies that more effectively target tumors and that are less susceptible to tumor immune evasion. ©2015 American Association for Cancer Research.

Design of ligand-targeted nanoparticles for enhanced cancer targeting

NASA Astrophysics Data System (ADS)

Stefanick, Jared F.

Ligand-targeted nanoparticles are increasingly used as drug delivery vehicles for cancer therapy, yet have not consistently produced successful clinical outcomes. Although these inconsistencies may arise from differences in disease models and target receptors, nanoparticle design parameters can significantly influence therapeutic efficacy. By employing a multifaceted synthetic strategy to prepare peptide-targeted nanoparticles with high purity, reproducibility, and precisely controlled stoichiometry of functionalities, this work evaluates the roles of polyethylene glycol (PEG) coating, ethylene glycol (EG) peptide-linker length, peptide hydrophilicity, peptide density, and nanoparticle size on tumor targeting in a systematic manner. These parameters were analyzed in multiple disease models by targeting human epidermal growth factor receptor 2 (HER2) in breast cancer and very late antigen-4 (VLA-4) in multiple myeloma to demonstrate the widespread applicability of this approach. By increasing the hydrophilicity of the targeting peptide sequence and simultaneously optimizing the EG peptide-linker length, the in vitro cellular uptake of targeted liposomes was significantly enhanced. Specifically, including a short oligolysine chain adjacent to the targeting peptide sequence effectively increased cellular uptake ~80-fold using an EG6 peptide-linker compared to ~10-fold using an EG45 linker. In vivo, targeted liposomes prepared in a traditional manner lacking the oligolysine chain demonstrated similar biodistribution and tumor uptake to non-targeted liposomes. However, by including the oligolysine chain, targeted liposomes using an EG45 linker significantly improved tumor uptake ~8-fold over non-targeted liposomes, while the use of an EG6 linker decreased tumor accumulation and uptake, owing to differences in cellular uptake kinetics, clearance mechanisms, and binding site barrier effects. To further improve tumor targeting and enhance the selectivity of targeted nanoparticles, a dual-receptor targeted approach was evaluated by targeting multiple cell surface receptors simultaneously. Liposomes functionalized with two distinct peptide antagonists to target VLA-4 and Leukocyte Peyer's Patch Adhesion Molecule-1 (LPAM-1) demonstrated synergistically enhanced cellular uptake by cells overexpressing both target receptors and negligible uptake by cells that do not simultaneously express both receptors, providing a strategy to improve selectivity over conventional single receptor-targeted designs. Taken together, this process of systematic optimization of well-defined nanoparticle drug delivery systems has the potential to improve cancer therapy for a broader patient population.

Orexin–Corticotropin-Releasing Factor Receptor Heteromers in the Ventral Tegmental Area as Targets for Cocaine

PubMed Central

Navarro, Gemma; Quiroz, César; Moreno-Delgado, David; Sierakowiak, Adam; McDowell, Kimberly; Moreno, Estefanía; Rea, William; Cai, Ning-Sheng; Aguinaga, David; Howell, Lesley A.; Hausch, Felix; Cortés, Antonio; Mallol, Josefa; Casadó, Vicent; Lluís, Carme; Canela, Enric I.

2015-01-01

Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R–OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R–OX1R heteromer. Cocaine binding to the σ1R–CRF1R–OX1R complex promotes a long-term disruption of the orexin-A–CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking. PMID:25926444

Targeting striatal metabotropic glutamate receptor type 5 in Parkinson's disease: bridging molecular studies and clinical trials.

PubMed

Vallano, A; Fernandez-Duenas, V; Garcia-Negredo, G; Quijada, M A; Simon, C P; Cuffí, M L; Carbonell, L; Sanchez, S; Arnau, J M; Ciruela, F

2013-12-01

Metabotropic glutamate (mGlu) receptors are G protein-coupled receptors expressed primarily on neurons and glial cells modulating the effects of glutamatergic neurotransmission. The pharmacological manipulation of these receptors has been postulated to be valuable in the management of some neurological disorders. Accordingly, the targeting of mGlu5 receptors as a therapeutic approach for Parkinson's disease (PD) has been proposed, especially to manage the adverse symptoms associated to chronic treatment with classical PD drugs. Thus, the specific pharmacological blocking of mGlu5 receptors constitutes one of the most attractive non-dopaminergic-based strategies for PD management in general and for the L-DOPA-induced dyskinesia (LID) in particular. Overall, we provide here an update of the current state of the art of these mGlu5 receptor-based approaches that are under clinical study as agents devoted to alleviate PD symptoms.

Safety and efficacy evaluation of gelatin-based nanoparticles associated with UV filters.

PubMed

Oliveira, Camila Areias de; Dario, Michelli Ferrera; Sarruf, Fernanda Daud; Mariz, Inês Fátima Afonso; Velasco, Maria Valéria Robles; Rosado, Catarina; Baby, André Rolim

2016-04-01

The safety and efficacy assessment of nanomaterials is a major concern of industry and academia. These materials, due to their nanoscale size, can have chemical, physical, and biological properties that differ from those of their larger counterparts. The encapsulation of natural ingredients can provide marked improvements in sun protection efficacy. This strategy promotes solubility enhancement of flavonoids and yields an improved active ingredient with innovative physical, physicochemical and functional characteristics. Rutin, a flavonoid, has chemical and functional stability in topical vehicles exerting a synergistic effect in association with ultraviolet (UV) filters. However, the solubility of rutin is a limiting factor. Additionally, this bioactive compound does not have tendency to permeate across the stratum corneum. As an alternative to common synthetic based sunscreens, rutin-entrapped gelatin nanoparticles were designed. The present study investigated the pre-clinical safety of gelatin nanoparticles (GNPs) using an in vitro method and also assessed the clinical safety and efficacy of the association of GNPs with three commonly used chemical UV filters (ethylhexyl dimethyl PABA, ethylhexyl methoxycinnamate and methoxydibenzoylmethane). The non-irritant and adequate safety profile under sun-exposed skin conditions of the nanomaterials and the emulsions qualified the products for clinical efficacy assays. The in vivo results indicated that the GNPs increased the antioxidant protection of the emulsions developed. However, the presence of rutin in the nanosized material did not enhance performance on the SPF test. In conclusion, these findings characterized the nanomaterials as an innovative platform for multifunctional bioactive sunscreens. Copyright © 2015 Elsevier B.V. All rights reserved.

Quantitative Impact of Plasma Clearance and Down-regulation on GLP-1 Receptor Molecular Imaging

PubMed Central

Zhang, Liang; Thurber, Greg M.

2016-01-01

Purpose Quantitative molecular imaging of beta cell mass (BCM) would enable early detection and treatment monitoring of type-1 diabetes. The glucagon like peptide-1 (GLP-1) receptor is an attractive target due to its beta cell specificity and cell surface location. We quantitatively investigated the impact of plasma clearance and receptor internalization on targeting efficiency in healthy B6 mice. Procedures Four exenatide-based probes were synthesized that varied in molecular weight, binding affinity, and plasma clearance. The GLP-1 receptor internalization rate and in vivo receptor expression were quantified. Results Receptor internalization (54,000 receptors/cell in vivo) decreased significantly within minutes, reducing the benefit of a slower clearing agent. The multimers and albumin binding probes had higher kidney and liver uptake, respectively. Conclusions Slow plasma clearance is beneficial for GLP-1 receptor peptide therapeutics. However, for exendin-based imaging of islets, downregulation of the GLP-1 receptor and non-specific background uptake result in a higher TBR for fast-clearing agents. PMID:26194012

The Na+-Taurocholate Cotransporting Polypeptide Traffics with the Epidermal Growth Factor Receptor

PubMed Central

Wang, Xintao; Wang, Pijun; Wang, Wenjun; Murray, John W.; Wolkoff, Allan W.

2015-01-01

Na+-taurocholate cotransporting polypeptide (ntcp) mediates uptake of bile acids as well as serving as the receptor for hepatitis B virus in human liver. Previous studies showed that ntcp traffics on microtubules between the cell surface and endocytic vesicles. Specific inhibition of protein kinase C (PKC)ζ resulted in loss of microtubule-based motility of these vesicles in vitro and in living cells. The aim of the present study was to characterize the PKCζ target. Incubation of ntcp-containing endocytic vesicles with γ-32P-ATP revealed a 180 kDa phosphoglycoprotein that was identified as the EGF receptor (EGFR). Surface biotinylation of HuH7 cells expressing GFP-ntcp revealed substantially reduced trafficking of ntcp to the cell surface with EGFR knockdown. Microtubule-based motility of ntcp-containing endocytic vesicles was also significantly reduced when they were not associated with EGFR. Ntcp was also found to undergo cellular redistribution upon stimulation of cells with EGF, consistent with a model in which ntcp and EGF-EGFR internalize into common endocytic vesicles from which they segregate, trafficking EGF-EGFR to lysosomes and recycling ntcp to the plasma membrane. EGF regulation of ntcp trafficking may play a heretofore unanticipated role in subcellular targeting of ntcp ligands such as hepatitis B. PMID:26650232

The Dynamic Behaviour of Ballistic Gelatin

NASA Astrophysics Data System (ADS)

Shepherd, C. J.; Appleby-Thomas, G. J.; Hazell, P. J.; Allsop, D. F.

2009-12-01

In order to characterise the effect of projectiles it is necessary to understand the mechanism of both penetration and resultant wounding in biological systems. Porcine gelatin is commonly used as a tissue simulant in ballistic tests because it elastically deforms in a similar manner to muscular tissue. Bullet impacts typically occur in the 350-850 m/s range; thus knowledge of the high strain-rate dynamic properties of both the projectile and target materials are desirable to simulate wounds. Unlike projectile materials, relatively little data exists on the dynamic response of flesh simulants. The Hugoniot for a 20 wt.% porcine gelatin, which exhibits a ballistic response similar to that of human tissues at room temperature, was determined using the plate-impact technique at impact velocities of 75-860 m/s. This resulted in impact stresses around three times higher than investigated elsewhere. In US-uP space the Hugoniot had the form US = 1.57+1.77 uP, while in P-uP space it was essentially hydrodynamic. In both cases this was in good agreement with the limited available data from the literature.

Pig Organ Energy Loss Comparison Experiments Using BBs.

PubMed

Maiden, Nicholas R; Musgrave, Ian; Fisk, Wesley; Byard, Roger W

2016-05-01

Torso models for ballistics research require that the mechanical properties of simulant materials must match the heterogeneous nature of tissues/organs within the human thorax/abdomen. A series of energy loss experiments were conducted on fresh porcine organs/tissues at room temperature and 37°C, using steel 4.5 mm BBs fired from a Daisy(®) brand air rifle. They were compared to FBI and NATO specification ordnance gelatin and a candidate surrogate material called Simulant "A". Two CED M2 chronographs measured BB velocity. The resulting energy loss was established using KE = 1/2 mv² before and after target perforation. The combined results at room temperature and 37°C were as follows: FBI specification gelatin was similar (p > 0.05) to heart and lung, spleen was similar to NATO specification gelatin, Simulant "A" was similar to hindquarter muscle, and hindquarter muscle, kidney, and spleen were similar to each other regarding energy retardation. These results can be used as a basis for the development of simulant materials to create an anatomically correct heterogeneous model. © 2016 American Academy of Forensic Sciences.

Microfluidic Synthesis of Composite Cross-Gradient Materials for Investigating Cell–Biomaterial Interactions

PubMed Central

He, Jiankang; Du, Yanan; Guo, Yuqi; Hancock, Matthew J.; Wang, Ben; Shin, Hyeongho; Wu, Jinhui; Li, Dichen; Khademhosseini, Ali

2010-01-01

Combinatorial material synthesis is a powerful approach for creating composite material libraries for the high-throughput screening of cell–material interactions. Although current combinatorial screening platforms have been tremendously successful in identifying target (termed “hit”) materials from composite material libraries, new material synthesis approaches are needed to further optimize the concentrations and blending ratios of the component materials. Here we employed a microfluidic platform to rapidly synthesize composite materials containing cross-gradients of gelatin and chitosan for investigating cell–biomaterial interactions. The microfluidic synthesis of the cross-gradient was optimized experimentally and theoretically to produce quantitatively controllable variations in the concentrations and blending ratios of the two components. The anisotropic chemical compositions of the gelatin/chitosan cross-gradients were characterized by Fourier transform infrared spectrometry and X-ray photoelectron spectrometry. The three-dimensional (3D) porous gelatin/chitosan cross-gradient materials were shown to regulate the cellular morphology and proliferation of smooth muscle cells (SMCs) in a gradient-dependent manner. We envision that our microfluidic cross-gradient platform may accelerate the material development processes involved in a wide range of biomedical applications. PMID:20721897

Gelatin-induced T-cell activation in children with nonanaphylactic-type reactions to vaccines containing gelatin.

PubMed

Taniguchi, K; Fujisawa, T; Ihara, T; Kamiya, H

1998-12-01

Many cases of anaphylactic or nonanaphylactic reactions have been reported to measles-mumps-rubella vaccine or its component vaccines that contain gelatin as a stabilizer. Increased levels of specific IgE antibodies to gelatin have been reported in children with anaphylactic reactions. However, IgE is not increased in cases of nonanaphylactic reaction, and the mechanisms of the reaction are still controversial. The study was aimed to elucidate the relationship between nonanaphylactic reaction and gelatin. We investigated in vitro induction of activated memory helper T cells (CD4(+ )CD25(+ )CD45RO+ cells) in response to gelatin in children with nonanaphylactic reactions to vaccines containing gelatin. In patients with delayed-type sensitivity to gelatin confirmed with a positive skin test response, CD4(+ )CD25(+ )CD45RO+ cells were significantly more strongly induced in culture containing gelatin than in control cultures. However, there was no significant difference between cultures with gelatin and those with control solvent in patients without reactions after vaccination. Of 76 patients with nonanaphylactic reactions after immunization with vaccine containing gelatin, 61 had an increased lymphocyte stimulation index to gelatin versus control children. These results suggest the possibility that nonanaphylactic reactions to gelatin-containing vaccine in Japan might be mediated by delayed hypersensitivity reactions against gelatin.

Polymer gel dosimeter with AQUAJOINT® as hydrogel matrix

NASA Astrophysics Data System (ADS)

Maeyama, Takuya; Ishida, Yasuhiro; Kudo, Yoshihiro; Fukasaku, Kazuaki; Ishikawa, Kenichi L.; Fukunishi, Nobuhisa

2018-05-01

We report a polymer gel dosimeter based on a new gel matrix (AQUAJOINT®) that is a thermo-irreversible hydrogel formed by mixing two types of water-based liquids at room temperature. Normoxic N-vinylpyrrolidone-based polymer gels were prepared with AQUAJOINT® instead of gelatin. This AQUAJOINT®-based gel dosimeter exhibits a 2.5-fold increase in sensitivity over a gelatin-based gel dosimeter and a linear dose-response in the dose range of 0-8 Gy. This gel has heat resistance in a jar and controlled gel properties such as viscoelastic and mechanical characters, which may be useful for deformable polymer gel dosimetry.

Characteristic study of chitosan addition in Tilapia (Oreochromis niloticus) bone based gelatin film

NASA Astrophysics Data System (ADS)

Atmaka, W.; Yudhistira, B.; Putro, M. I. S.

2018-03-01

Tilapia (Oreochromis niloticus) is one of popular fish species in Indonesia. The high number in tilapia’s production and export of tilapia resulting in the increase of bone fish waste. an attempt to decrease the amount of the aforementioned waste, the fish bones were turned into gelatine. The gelatine produced from this waste can be put to good use by turning it into edible film due to its high water resistance and low tensile strength value. However, in order to make a proper film, both the water resistance and the tensile strength value needs another appropriate additional biopolymer. In this case, the appropriate biopolymer needed both to form the film and to repair its characteristics is chitosan. The purpose of this research is to find out the effect of the chitosan addition on the tilapia bone based gelatine film. The research used several mixtures of gelatine (G) and chitosan (C) with the following ratio: G100:C0 (GC1), G75:C25 (GC2), G50:C50 (GC3), G25:C75 (GC4), G0:C100 (GC5). ANOVA results (P<0.05) shows that the addition of chitosan on the gelatine film affected its characteristics in thickness, solubility, tensile strength, elongation at break, Fourier Transform Infrared (FTIR), color a, and color b but no significant effects on the vapor permeability and color L. The best result is shown on GC2 with thickness 0.119 mm; solubility 74.95%; tensile strength 2.635 Mpa; elongation at break 68.26%; water vapor permeability 5.897 g/h m2 and FTIR. The parameters in GC2 shows good compatibility between the two biopolymers.

IgE antibody to fish gelatin (type I collagen) in patients with fish allergy.

PubMed

Sakaguchi, M; Toda, M; Ebihara, T; Irie, S; Hori, H; Imai, A; Yanagida, M; Miyazawa, H; Ohsuna, H; Ikezawa, Z; Inouye, S

2000-09-01

Most children with anaphylaxis to measles, mumps, and rubella vaccines had shown sensitivity to bovine gelatin that was included in the vaccines. Recently, it was found that bovine type I collagen, which is the main content in the gelatin, is a major allergen in bovine gelatin allergy. Fish meat and skin also contain type I collagen. The present study was designed to investigate IgE antibody to fish gelatin in children with fish allergy. Serum samples were taken from patients in 3 groups: (1) 10 patients with fish allergy and specific IgE to fish meat; (2) two patients with allergies to both fish meat and bovine gelatin and specific IgE to fish meat and bovine gelatin; and (3) 15 patients with atopic dermatitis and specific IgE to fish meat. Various fish gelatins (type I collagen) were prepared from fish skin. IgE antibody to fish gelatin was analyzed by using ELISA and immunoblotting. Of 10 patients with fish allergy, 3 had specific IgE to fish gelatin. Of two patients with fish allergy and bovine gelatin allergy, all had specific IgE to fish gelatin. Of 15 patients with atopic dermatitis and specific IgE to fish meat, 5 had specific IgE to fish gelatin. Furthermore, IgE from pooled serum of the patients reacted with both the alpha1 and alpha2 chains of fish type I collagen in immunoblots. There is cross-reactivity among gelatins from various fishes, but there is little cross-reactivity between fish and bovine gelatins. Some fish-sensitive patients possessed IgE antibody to fish gelatin. Fish gelatin (type I collagen) might be an allergen in subjects with fish allergy.

The Target Residence Time of Antihistamines Determines Their Antagonism of the G Protein-Coupled Histamine H1 Receptor

PubMed Central

Bosma, Reggie; Witt, Gesa; Vaas, Lea A. I.; Josimovic, Ivana; Gribbon, Philip; Vischer, Henry F.; Gul, Sheraz; Leurs, Rob

2017-01-01

The pharmacodynamics of drug-candidates is often optimized by metrics that describe target binding (Kd or Ki value) or target modulation (IC50). However, these metrics are determined at equilibrium conditions, and consequently information regarding the onset and offset of target engagement and modulation is lost. Drug-target residence time is a measure for the lifetime of the drug-target complex, which has recently been receiving considerable interest, as target residence time is shown to have prognostic value for the in vivo efficacy of several drugs. In this study, we have investigated the relation between the increased residence time of antihistamines at the histamine H1 receptor (H1R) and the duration of effective target-inhibition by these antagonists. Hela cells, endogenously expressing low levels of the H1R, were incubated with a series of antihistamines and dissociation was initiated by washing away the unbound antihistamines. Using a calcium-sensitive fluorescent dye and a label free, dynamic mass redistribution based assay, functional recovery of the H1R responsiveness was measured by stimulating the cells with histamine over time, and the recovery was quantified as the receptor recovery time. Using these assays, we determined that the receptor recovery time for a set of antihistamines differed more than 40-fold and was highly correlated to their H1R residence times, as determined with competitive radioligand binding experiments to the H1R in a cell homogenate. Thus, the receptor recovery time is proposed as a cell-based and physiologically relevant metric for the lead optimization of G protein-coupled receptor antagonists, like the H1R antagonists. Both, label-free or real-time, classical signaling assays allow an efficient and physiologically relevant determination of kinetic properties of drug molecules. PMID:29033838

The 150 most important questions in cancer research and clinical oncology series: questions 50-56.

PubMed

2017-08-29

Since the beginning of 2017, Chinese Journal of Cancer has published a series of important questions in cancer research and clinical oncology, which sparkle diverse thoughts, interesting communications, and potential collaborations among researchers all over the world. In this article, seven more questions are presented as followed. Question 50. When tumor cells spread from primary site to distant sites, are they required to be "trained" or "armed" in the bone marrow niche prior to colonizing soft tissues? Question 51. Are there tipping points during cancer progression which can be identified for manipulation? Question 52. Can we replace molecular biomarkers by network biomarkers? Question 53. Are conventional inhibitors of key cellular processes such as cell proliferation and differentiation more effective than targeted chemotherapeutics that antagonize the downstream cell signaling network via cell-surface receptors such as epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor (VEGFR) and c-Met, or intracellular receptors such as androgen receptor (AR) and estrogen receptor (ER), by drugs like erlotinib, sunitinib and cabozantinib, or enzalutamide and tomoxifen? Question 54. How can we robustly identify the candidate causal event of somatic genome alteration (SGA) by using computational approach? Question 55. How can we systematically reveal the immune evasion mechanism exploited by each tumor and utilize such information to guide targeted therapy to restore immune sensitivity? Question 56. Can the nasopharyngeal carcinoma (NPC) patients with sarcomatoid carcinoma (SC) subtype benefit from more specific targeted therapy?

A peptide representing the carboxyl-terminal tail of the met receptor inhibits kinase activity and invasive growth.

PubMed

Bardelli, A; Longati, P; Williams, T A; Benvenuti, S; Comoglio, P M

1999-10-08

Interaction of the hepatocyte growth factor (HGF) with its receptor, the Met tyrosine kinase, results in invasive growth, a genetic program essential to embryonic development and implicated in tumor metastasis. Met-mediated invasive growth requires autophosphorylation of the receptor on tyrosines located in the kinase activation loop (Tyr(1234)-Tyr(1235)) and in the carboxyl-terminal tail (Tyr(1349)-Tyr(1356)). We report that peptides derived from the Met receptor tail, but not from the activation loop, bind the receptor and inhibit the kinase activity in vitro. Cell delivery of the tail receptor peptide impairs HGF-dependent Met phosphorylation and downstream signaling. In normal and transformed epithelial cells, the tail receptor peptide inhibits HGF-mediated invasive growth, as measured by cell migration, invasiveness, and branched morphogenesis. The Met tail peptide inhibits the closely related Ron receptor but does not significantly affect the epidermal growth factor, platelet-derived growth factor, or vascular endothelial growth factor receptor activities. These experiments show that carboxyl-terminal sequences impair the catalytic properties of the Met receptor, thus suggesting that in the resting state the nonphosphorylated tail acts as an intramolecular modulator. Furthermore, they provide a strategy to selectively target the MET proto-oncogene by using small, cell-permeable, peptide derivatives.

Enteric coating of soft gelatin capsules by spouted bed: effect of operating conditions on coating efficiency and on product quality.

PubMed

Pissinati, Rafael; Oliveira, Wanderley Pereira

2003-05-01

The present study was conducted in order to analyze the viability of the spouted bed process for application of a gastric-resistant coating to soft gelatin capsules. The variables investigated were: included angle of conical base, (gamma), the relation between the feed mass flow rate of the coating suspension and the feed mass flow rate of spouting gas (W(s)/W(g)); the ratio between the flow rate of the spouting gas and the flow rate at minimum spouting condition (Q/Q(ms)); the mass of capsules in the bed (M(0)), and the capsule's size. The product quality was measured by disintegration tests, traction x deformation tests, image analysis and by the evaluation of the coating mass distribution and shape factor variation during the coating operation. The experiments were performed in a spouted bed with a column diameter of 200 mm and included a conical base angle of 40 degrees. The best coating efficiency values were obtained for M(0)=300 g. Coating efficiency tended to increase with increasing W(s)/W(g) ratio. Disintegration tests showed that the gastric-resistant effect was obtained with a coating mass of 3.86 mg/cm(2). The shape factor increase during the coating operation. The capsule's coating mass distribution tended to maintain the original distribution.

Adenosine receptors and caffeine in retinopathy of prematurity

PubMed Central

Chen, Jiang-Fan; Zhang, Shuya; Zhou, Rong; Lin, Zhenlang; Cai, Xiaohong; Lin, Jing; Huo, Yuqing; Liu, Xiaoling

2017-01-01

Retinopathy of prematurity (ROP) is a major cause of childhood blindness in the world and is caused by oxygen-induced damage to the developing retinal vasculature, resulting in hyperoxia-induced vaso-obliteration and subsequent delayed retinal vascularization and hypoxia-induced pathological neovascularization driven by vascular endothelial growth factor (VEGF) signaling pathway in retina. Current anti-VEGF therapy has shown some effective in a clinical trial, but is associated with the unintended effects on delayed eye growth and retinal vasculature development of preterm infants. Notably, cellular responses to hypoxia are characterized by robust increases in extracellular adenosine production and the markedly induced adenosine receptors, which provide a novel target for preferential control of pathological angiogenesis without affecting normal vascular development. Here, we review the experimental evidence in support of adenosine receptor-based therapeutic strategy for ROP, including the aberrant adenosine signaling in oxygen-induced retinopathy and the role of three adenosine receptor subtypes (A1R, A2AR, A2BR) in development and treatment of ROP using oxygen-induced retinopathy models. The clinical and initial animal evidence that implicate the therapeutic effect of caffeine (a non-selective adenosine receptor antagonist) in treatment of ROP are highlighted. Lastly, we discussed the translational potential as well therapeutic advantage of adenosine receptor- and caffeine-based therapy for ROR and possibly other proliferative retinopathy. PMID:28088487

Mapping the Dynamics of the Glucocorticoid Receptor within the Nuclear Landscape.

PubMed

Stortz, Martin; Presman, Diego M; Bruno, Luciana; Annibale, Paolo; Dansey, Maria V; Burton, Gerardo; Gratton, Enrico; Pecci, Adali; Levi, Valeria

2017-07-24

The distribution of the transcription machinery among different sub-nuclear domains raises the question on how the architecture of the nucleus modulates the transcriptional response. Here, we used fluorescence fluctuation analyses to quantitatively explore the organization of the glucocorticoid receptor (GR) in the interphase nucleus of living cells. We found that this ligand-activated transcription factor diffuses within the nucleus and dynamically interacts with bodies enriched in the coregulator NCoA-2, DNA-dependent foci and chromatin targets. The distribution of the receptor among the nuclear compartments depends on NCoA-2 and the conformation of the receptor as assessed with synthetic ligands and GR mutants with impaired transcriptional abilities. Our results suggest that the partition of the receptor in different nuclear reservoirs ultimately regulates the concentration of receptor available for the interaction with specific targets, and thus has an impact on transcription regulation.

Fabrication and Physical Evaluation of Gelatin-Coated Carbonate Apatite Foam

PubMed Central

Hara, Kanae; Fujisawa, Kenji; Nagai, Hirokazu; Takamaru, Natsumi; Ohe, Go; Tsuru, Kanji; Ishikawa, Kunio; Miyamoto, Youji

2016-01-01

Carbonate apatite (CO3Ap) foam has gained much attention in recent years because of its ability to rapidly replace bone. However, its mechanical strength is extremely low for clinical use. In this study, to understand the potential of gelatin-reinforced CO3Ap foam for bone replacement, CO3Ap foam was reinforced with gelatin and the resulting physical characteristics were evaluated. The mechanical strength increased significantly with the gelatin reinforcement. The compressive strength of gelatin-free CO3Ap foam was 74 kPa whereas that of the gelatin-reinforced CO3Ap foam, fabricated using 30 mass % gelatin solution, was approximately 3 MPa. Heat treatment for crosslinking gelatin had little effect on the mechanical strength of the foam. The gelatin-reinforced foam did not maintain its shape when immersed in a saline solution as this promoted swelling of the gelatin; however, in the same conditions, the heat-treated gelatin-reinforced foam proved to be stable. It is concluded, therefore, that heat treatment is the key to the fabrication of stable gelatin-reinforced CO3Ap foam. PMID:28773832

Extraction and physicochemical characterization of broiler (Gallus gallus domesticus) skin gelatin compared to commercial bovine gelatin.

PubMed

Aykin-Dinçer, E; Koç, A; Erbas, M

2017-09-01

Gelatin was extracted from broiler (Gallus gallus domesticus) skins and analyzed to compare its physicochemical properties with those of commercial bovine gelatin. The average yield of broiler skin gelatin was 6.5% on a wet weight basis. Broiler skin gelatin had more α1-and α2-chains than β-chain and contained high molecular weight (γ-chain) polymers. Glycine was the dominant amino acid in broiler skin gelatin (20.26%), followed by proline (Pro) (15.12%) then hydroxyproline (Hyp) (11.36%). Compared to commercial bovine gelatin, broiler skin gelatin had less total imino acids (Pro and Hyp) but a higher (33.65 vs. 31.38°C) melting temperature (P < 0.01). The differences in physical properties between the broiler and commercial bovine gelatins appeared to be associated with differences in their amino acid composition and molecular weight distribution. The sensory evaluation results revealed that broiler skin gelatin could be a potential alternative to commercial bovine gelatin, useful in various food products. © 2017 Poultry Science Association Inc.

Therapeutic Targeting of Siglecs using Antibody- and Glycan-based Approaches

PubMed Central

Angata, Takashi; Nycholat, Corwin M.; Macauley, Matthew S.

2015-01-01

The sialic acid-binding immunoglobulin-like lectins (Siglecs) are a family of immunomodulatory receptors whose functions are regulated by their glycan ligands. Siglecs are attractive therapeutic targets because of their cell-type specific expression pattern, endocytic properties, high expression on certain lymphomas/leukemias, and ability to modulate receptor signaling. Siglec-targeting approaches with therapeutic potential encompass antibody- and glycan-based strategies. Several antibody-based therapies are in clinical trials and continue to be developed for the treatment of lymphoma/leukemia and autoimmune disease, while the therapeutic potential of glycan-based strategies for cargo-delivery and immunomodulation is a promising new approach. Here, we review these strategies with special emphasis on emerging approaches and disease areas that may benefit from targeting the Siglec family. PMID:26435210

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ausborn, Natalie L.; Le, Quynh Thu; Bradley, Jeffrey D.

Therapeutic decisions in non-small cell lung cancer (NSCLC) have been mainly based on disease stage, performance status, and co-morbidities, and rarely on histological or molecular classification. Rather than applying broad treatments to unselected patients that may result in survival increase of only weeks to months, research efforts should be, and are being, focused on identifying predictive markers for molecularly targeted therapy and determining genomic signatures that predict survival and response to specific therapies. The availability of such targeted biologics requires their use to be matched to tumors of corresponding molecular vulnerability for maximum efficacy. Molecular markers such as epidermal growthmore » factor receptor (EGFR), K-ras, vascular endothelial growth factor (VEGF), mammalian target of rapamycin (mTOR), and anaplastic lymphoma kinase (ALK) represent potential parameters guide treatment decisions. Ultimately, identifying patients who will respond to specific therapies will allow optimal efficacy with minimal toxicity, which will result in more judicious and effective application of expensive targeted therapy as the new paradigm of personalized medicine develops.« less

Clinical validation of nuclear factor kappa B expression in invasive breast cancer.

PubMed

Agrawal, Anil Kumar; Pielka, Ewa; Lipinski, Artur; Jelen, Michal; Kielan, Wojciech; Agrawal, Siddarth

2018-01-01

Breast cancer is the most commonly diagnosed cancer in Polish women. The expression of transcription nuclear factor kappa B, a key inducer of inflammatory response promoting carcinogenesis and cancer progression in breast cancer, is not well-established. We assessed the nuclear factor kappa B expression in a total of 119 invasive breast carcinomas and 25 healthy control samples and correlated this expression pattern with several clinical and pathologic parameters including histologic type and grade, tumor size, lymph node status, estrogen receptor status, and progesterone receptor status. The data used for the analysis were derived from medical records. An immunohistochemical analysis of nuclear factor kappa B, estrogen receptor, and progesterone receptor was carried out and evaluation of stainings was performed. The expression of nuclear factor kappa B was significantly higher than that in the corresponding healthy control samples. No statistical difference was demonstrated in nuclear factor kappa B expression in relation to age, menopausal status, lymph node status, tumor size and location, grade and histologic type of tumor, and hormonal status (estrogen receptor and progesterone receptor). Nuclear factor kappa B is significantly overexpressed in invasive breast cancer tissues. Although nuclear factor kappa B status does not correlate with clinicopathological findings, it might provide important additional information on prognosis and become a promising object for targeted therapy.

Designer interface peptide grafts target estrogen receptor alpha dimerization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakraborty, S.; Asare, B.K.; Biswas, P.K., E-mail: pbiswas@tougaloo.edu

The nuclear transcription factor estrogen receptor alpha (ERα), triggered by its cognate ligand estrogen, regulates a variety of cellular signaling events. ERα is expressed in 70% of breast cancers and is a widely validated target for anti-breast cancer drug discovery. Administration of anti-estrogen to block estrogen receptor activation is still a viable anti-breast cancer treatment option but anti-estrogen resistance has been a significant bottle-neck. Dimerization of estrogen receptor is required for ER activation. Blocking ERα dimerization is therefore a complementary and alternative strategy to combat anti-estrogen resistance. Dimer interface peptide “I-box” derived from ER residues 503–518 specifically blocks ER dimerization.more » Recently using a comprehensive molecular simulation we studied the interaction dynamics of ERα LBDs in a homo-dimer. Based on this study, we identified three interface recognition peptide motifs LDKITDT (ERα residues 479–485), LQQQHQRLAQ (residues 497–506), and LSHIRHMSNK (residues 511–520) and reported the suitability of using LQQQHQRLAQ (ER 497–506) as a template to design inhibitors of ERα dimerization. Stability and self-aggregation of peptide based therapeutics poses a significant bottle-neck to proceed further. In this study utilizing peptide grafted to preserve their pharmacophoric recognition motif and assessed their stability and potential to block ERα mediated activity in silico and in vitro. The Grafted peptides blocked ERα mediated cell proliferation and viability of breast cancer cells but did not alter their apoptotic fate. We believe the structural clues identified in this study can be used to identify novel peptidometics and small molecules that specifically target ER dimer interface generating a new breed of anti-cancer agents. - Highlights: • Designer peptide grafts retain core molecular recognition motif during MD simulations. • Designer peptide grafts with Poly-ALA helix form stable complexes with estrogen receptor in silico. • Inhibitor peptides significantly decrease estrogen induced cell proliferation of ER positive breast cancer cells in vitro.« less

Comparison of water gel desserts from fish skin and pork gelatins using instrumental measurements.

PubMed

Zhou, Peng; Regenstein, Joe M

2007-05-01

The objective of this study was to compare water gel desserts from various gelatins using instrumental measurements. The puncture test and texture profile analysis (TPA) with compression were determined at 25% and 75% deformation; the melting properties were determined rheologically by monitoring the change of storage modulus (G') with increasing temperature. The measurements with 25% deformation were always nondestructive, while measurements with 75% deformation were mostly destructive. Desserts made from Alaska pollock gelatin (AG) or gelatin mixtures containing AG were more resistant to the destruction caused by the large deformation than tilapia gelatin and pork gelatins. In addition, the gel dessert made from AG melted at a lower temperature than those from tilapia skin gelatin and pork gelatins, while desserts made from gelatin mixtures reflected the melting properties of the separate gelatins.

Halal authenticity of gelatin using species-specific PCR.

PubMed

Shabani, Hessam; Mehdizadeh, Mehrangiz; Mousavi, Seyed Mohammad; Dezfouli, Ehsan Ansari; Solgi, Tara; Khodaverdi, Mahdi; Rabiei, Maryam; Rastegar, Hossein; Alebouyeh, Mahmoud

2015-10-01

Consumption of food products derived from porcine sources is strictly prohibited in Islam. Gelatin, mostly derived from bovine and porcine sources, has many applications in the food and pharmaceutical industries. To ensure that food products comply with halal regulations, development of valid and reliable analytical methods is very much required. In this study, a species-specific polymerase chain reaction (PCR) assay using conserved regions of mitochondrial DNA (cytochrome b gene) was performed to evaluate the halal authenticity of gelatin. After isolation of DNA from gelatin powders with known origin, conventional PCR using species-specific primers was carried out on the extracted DNA. The amplified expected PCR products of 212 and 271 bp were observed for porcine and bovine gelatin, respectively. The sensitivity of the method was tested on binary gelatin mixtures containing 0.1%, 1%, 10%, and 100% (w/w) of porcine gelatin within bovine gelatin and vice versa. Although most of the DNA is degraded due to the severe processing steps of gelatin production, the minimum level of 0.1% w/w of both porcine and bovine gelatin was detected. Moreover, eight food products labeled as containing bovine gelatin and eight capsule shells were subjected to PCR examination. The results showed that all samples contained bovine gelatin, and the absence of porcine gelatin was verified. This method of species authenticity is very useful to verify whether gelatin and gelatin-containing food products are derived from halal ingredients. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lubricin Surface Modification Improves Tendon Gliding After Tendon Repair in a Canine Model in Vitro

PubMed Central

Taguchi, Manabu; Sun, Yu-Long; Zhao, Chunfeng; Zobitz, Mark E.; Cha, Chung-Ja; Jay, Gregory D.; An, Kai-Nan; Amadio, Peter C.

2011-01-01

This study investigated the effects of lubricin on the gliding of repaired flexor digitorum profundus (FDP) tendons in vitro. Canine FDP tendons were completely lacerated, repaired with a modified Pennington technique, and treated with one of the following solutions: saline, carbodiimide derivatized gelatin/hyaluronic acid (cd-HA-gelatin), carbodiimide derivatized gelatin to which lubricin was added in a second step (cd-gelatin + lubricin), or carbodiimide derivatized gelatin/HA + lubricin (cd-HA-gelatin + lubricin). After treatment, gliding resistance was measured up to 1,000 cycles of simulated flexion/extension motion. The increase in average and peak gliding resistance in cd-HA-gelatin, cd-gelatin + lubricin, and cd-HA-gelatin + lubricin tendons was less than the control tendons after 1,000 cycles (p < 0.05). The increase in average gliding resistance of cd-HA-gelatin + lubricin treated tendons was also less than that of the cd-HA-gelatin treated tendons (p < 0.05). The surfaces of the repaired tendons and associated pulleys were assessed qualitatively with scanning electron microscopy and appeared smooth after 1,000 cycles of tendon motion for the cd-HA-gelatin, cd-gelatin + lubricin, and cd-HA-gelatin + lubricin treated tendons, while that of the saline control appeared roughened. These results suggest that tendon surface modification can improve tendon gliding ability, with a trend suggesting that lubricin fixed on the repaired tendon may provide additional improvement over that provided by HA and gelatin alone. PMID:18683890

D-Glucose as a modifying agent in gelatin/collagen matrix and reservoir nanoparticles for Calendula officinalis delivery.

PubMed

Lam, P-L; Kok, S H-L; Bian, Z-X; Lam, K-H; Tang, J C-O; Lee, K K-H; Gambari, R; Chui, C-H

2014-05-01

Gelatin/Collagen-based matrix and reservoir nanoparticles require crosslinkers to stabilize the formed nanosuspensions, considering that physical instability is the main challenge of nanoparticulate systems. The use of crosslinkers improves the physical integrity of nanoformulations under the-host environment. Aldehyde-based fixatives, such as formaldehyde and glutaraldehyde, have been widely applied to the crosslinking process of polymeric nanoparticles. However, their potential toxicity towards human beings has been demonstrated in many previous studies. In order to tackle this problem, D-glucose was used during nanoparticle formation to stabilize the gelatin/collagen-based matrix wall and reservoir wall for the deliveries of Calendula officinalis powder and oil, respectively. In addition, therapeutic selectivity between malignant and normal cells could be observed. The C. officinalis powder loaded nanoparticles significantly strengthened the anti-cancer effect towards human breast adenocarcinoma MCF7 cells and human hepatoma SKHep1 cells when compared with the free powder. On the contrary, the nanoparticles did not show significant cytotoxicity towards normal esophageal epithelial NE3 cells and human skin keratinocyte HaCaT cells. On the basis of these evidences, D-glucose modified gelatin/collagen matrix nanoparticles containing C. officinalis powder might be proposed as a safer alternative vehicle for anti-cancer treatments. Copyright © 2014 Elsevier B.V. All rights reserved.

Harnessing Integrative Omics to Facilitate Molecular Imaging of the Human Epidermal Growth Factor Receptor Family for Precision Medicine.

PubMed

Pool, Martin; de Boer, H Rudolf; Hooge, Marjolijn N Lub-de; van Vugt, Marcel A T M; de Vries, Elisabeth G E

2017-01-01

Cancer is a growing problem worldwide. The cause of death in cancer patients is often due to treatment-resistant metastatic disease. Many molecularly targeted anticancer drugs have been developed against 'oncogenic driver' pathways. However, these treatments are usually only effective in properly selected patients. Resistance to molecularly targeted drugs through selective pressure on acquired mutations or molecular rewiring can hinder their effectiveness. This review summarizes how molecular imaging techniques can potentially facilitate the optimal implementation of targeted agents. Using the human epidermal growth factor receptor (HER) family as a model in (pre)clinical studies, we illustrate how molecular imaging may be employed to characterize whole body target expression as well as monitor drug effectiveness and the emergence of tumor resistance. We further discuss how an integrative omics discovery platform could guide the selection of 'effect sensors' - new molecular imaging targets - which are dynamic markers that indicate treatment effectiveness or resistance.

A pilot study of peptide vaccines for VEGF receptor 1 and 2 in patients with recurrent/progressive high grade glioma.

PubMed

Shibao, Shunsuke; Ueda, Ryo; Saito, Katsuya; Kikuchi, Ryogo; Nagashima, Hideaki; Kojima, Atsuhiro; Kagami, Hiroshi; Pareira, Eriel Sandika; Sasaki, Hikaru; Noji, Shinobu; Kawakami, Yutaka; Yoshida, Kazunari; Toda, Masahiro

2018-04-20

Early-phase clinical studies of glioma vaccines have shown feasibility and encouraging preliminary clinical activity. A vaccine that targets tumor angiogenesis factors in glioma microenvironment has not been reported. Therefore, we performed a pilot study to evaluate the safety and immunogenicity of a novel vaccination targeting tumor angiogenesis with synthetic peptides for vascular endothelial growth factor (VEGF) receptor epitopes in patients with recurrent/progressive high grade gliomas. Eight patients received intranodal vaccinations weekly at a dose of 2mg/kg bodyweight 8 times. T-lymphocyte responses against VEGF receptor (VEGFR) epitopes were assessed by enzyme linked immunosorbent spot assays. This treatment was well-tolerated in patients. The first four vaccines induced positive immune responses against at least one of the targeted VEGFR epitopes in the peripheral blood mononuclear cells in 87.5% of patients. The median overall survival time in all patients was 15.9 months. Two achieved progression-free status lasting at least 6 months. Two patients with recurrent GBM demonstrated stable disease. Plasma IL-8 level was negatively correlated with overall survival. These data demonstrate the safety and immunogenicity of VEGFR peptide vaccines targeting tumor vasculatures in high grade gliomas.

Neuropathogenic Escherichia coli K1 does not exhibit proteolytic activities to exert its pathogenicity.

PubMed

Iqbal, Junaid; Rajani, Mehak; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

2013-05-01

Proteases are well-known virulence factors that promote survival, pathogenesis and immune evasion of many pathogens. Several lines of evidence suggest that the blood-brain barrier permeability is a prerequisite in microbial invasion of the central nervous system. Because proteases are frequently associated with vascular permeability by targeting junctional proteins, here it is hypothesized that neuropathogenic Escherichia coli K1 exhibit proteolytic activities to exert its pathogenicity. Zymographic assays were performed using collagen and gelatin as substrates. The lysates of whole E. coli K1 strain E44, or E. coli K-12 strain HB101 were tested for proteolytic activities. The conditioned media were prepared by incubating bacteria in RPMI-1640 in the presence or absence of serum. The cell-free supernatants were collected and tested for proteases in zymography as mentioned above. Additionally, proteolytic degradation of host immune factors was determined by co-incubating conditioned media with albumin/immunoglobulins using protease assays. When collagen or gelatin were used as substrates in zymographic assays, neither whole bacteria nor conditioned media exhibited proteolytic activities. The conditioned media of neuropathogenic E. coli K1 strain E44, or E. coli K-12 strain HB101 did not affect degradation of albumin and immunoglobulins using protease assays. Neither zymographic assays nor protease assays detected proteolytic activities in either the whole bacteria or conditioned media of E. coli K1 strain E44 and E. coli K-12 strain HB101. These findings suggest that host cell monolayer disruptions and immune evasion strategies are likely independent of proteolytic activities of neuropathogenic E. coli K1.

Residues remote from the binding pocket control the antagonist selectivity towards the corticotropin-releasing factor receptor-1

PubMed Central

Sun, Xianqiang; Cheng, Jianxin; Wang, Xu; Tang, Yun; Ågren, Hans; Tu, Yaoquan

2015-01-01

The corticotropin releasing factors receptor-1 and receptor-2 (CRF1R and CRF2R) are therapeutic targets for treating neurological diseases. Antagonists targeting CRF1R have been developed for the potential treatment of anxiety disorders and alcohol addiction. It has been found that antagonists targeting CRF1R always show high selectivity, although CRF1R and CRF2R share a very high rate of sequence identity. This has inspired us to study the origin of the selectivity of the antagonists. We have therefore built a homology model for CRF2R and carried out unbiased molecular dynamics and well-tempered metadynamics simulations for systems with the antagonist CP-376395 in CRF1R or CRF2R to address this issue. We found that the side chain of Tyr6.63 forms a hydrogen bond with the residue remote from the binding pocket, which allows Tyr6.63 to adopt different conformations in the two receptors and results in the presence or absence of a bottleneck controlling the antagonist binding to or dissociation from the receptors. The rotameric switch of the side chain of Tyr3566.63 allows the breaking down of the bottleneck and is a perquisite for the dissociation of CP-376395 from CRF1R. PMID:25628267

Benzomorphan skeleton, a versatile scaffold for different targets: A comprehensive review.

PubMed

Turnaturi, Rita; Montenegro, Lucia; Marrazzo, Agostino; Parenti, Rosalba; Pasquinucci, Lorella; Parenti, Carmela

2018-06-07

Despite the fact that the benzomorphan skeleton has mainly been employed in medicinal chemistry for the development of opioid analgesics, it is a versatile structure. Its stereochemistry, as well as opportune modifications at the phenolic hydroxyl group and at the basic nitrogen, play a pivotal role addressing the benzomorphan-based compounds to a specific target. In this review, we describe the structure activity-relationships (SARs) of benzomorphan-based compounds acting at sigma 1 receptor (σ1R), sigma 2 receptor (σ2R), voltage-dependent sodium channel, N-Methyl-d-Aspartate (NMDA) receptor-channel complex and other targets. Collectively, the SARs data have highlighted that the benzomorphan nucleus could be regarded as a useful template for the synthesis of drug candidates for different targets. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Identification of the Niemann-Pick C1-like 1 cholesterol absorption receptor as a new hepatitis C virus entry factor

PubMed Central

Sainz, Bruno; Barretto, Naina; Martin, Danyelle N.; Hiraga, Nobuhiko; Imamura, Michio; Hussain, Snawar; Marsh, Katherine A.; Yu, Xuemei; Chayama, Kazuaki; Alrefai, Waddah A.; Uprichard, Susan L.

2011-01-01

Hepatitis C virus (HCV) is a leading cause of liver disease worldwide. With ~170 million individuals infected and current interferon-based treatment having toxic side-effects and marginal efficacy, more effective antivirals are critically needed1. Although HCV protease inhibitors were just FDA approved, analogous to HIV therapy, optimal HCV therapy likely will require a combination of antivirals targeting multiple aspects of the viral lifecycle. Viral entry represents a promising multi-faceted target for antiviral intervention; however, to date FDA-approved inhibitors of HCV cell entry are unavailable. Here we show that the cellular Niemann-Pick C1-Like 1 (NPC1L1) cholesterol uptake receptor is an HCV entry factor amendable to therapeutic intervention. Specifically, NPC1L1 expression is necessary for HCV infection as silencing or antibody-mediated blocking of NPC1L1 impairs cell-cultured-derived HCV (HCVcc) infection initiation. In addition, the clinically-available FDA-approved NPC1L1 antagonist ezetimibe2,3 potently blocks HCV uptake in vitro via a virion cholesterol-dependent step prior to virion-cell membrane fusion. Importantly, ezetimibe inhibits infection of all major HCV genotypes in vitro, and in vivo delays the establishment of HCV genotype 1b infection in mice with human liver grafts. Thus, we have not only identified NPC1L1 as an HCV cell entry factor, but also discovered a new antiviral target and potential therapeutic agent. PMID:22231557

Molecular docking, molecular modeling, and molecular dynamics studies of azaisoflavone as dual COX-2 inhibitors and TP receptor antagonists.

PubMed

Hadianawala, Murtuza; Mahapatra, Amarjyoti Das; Yadav, Jitender K; Datta, Bhaskar

2018-02-26

Designed multi-target ligand (DML) is an emerging strategy for the development of new drugs and involves the engagement of multiple targets with the same moiety. In the context of NSAIDs it has been suggested that targeting the thromboxane prostanoid (TP) receptor along with cyclooxygenase-2 (COX-2) may help to overcome cardiovascular (CVS) complications associated with COXIBs. In the present work, azaisoflavones were studied for their COX-2 and TP receptor binding activities using structure based drug design (SBDD) techniques. Flavonoids were selected as a starting point based on their known COX-2 inhibitory and TP receptor antagonist activity. Iterative design and docking studies resulted in the evolution of a new class scaffold replacing the benzopyran-4-one ring of flavonoids with quinolin-4-one. The docking and binding parameters of these new compounds are found to be promising in comparison to those of selective COX-2 inhibitors, such as SC-558 and celecoxib. Owing to the lack of structural information, a model for the TP receptor was generated using a threading base alignment method with loop optimization performed using an ab initio method. The model generated was validated against known antagonists for TP receptor using docking/MMGBSA. Finally, the molecules that were designed for selective COX-2 inhibition were docked into the active site of the TP receptor. Iterative structural modifications and docking on these molecules generated a series which displays optimum docking scores and binding interaction for both targets. Molecular dynamics studies on a known TP receptor antagonist and a designed molecule show that both molecules remain in contact with protein throughout the simulation and interact in similar binding modes. Graphical abstract ᅟ.

Anti-PDGF receptor β antibody-conjugated squarticles loaded with minoxidil for alopecia treatment by targeting hair follicles and dermal papilla cells.

PubMed

Aljuffali, Ibrahim A; Pan, Tai-Long; Sung, Calvin T; Chang, Shu-Hao; Fang, Jia-You

2015-08-01

This study developed lipid nanocarriers, called squarticles, conjugated with anti-platelet-derived growth factor (PDGF)-receptor β antibody to determine whether targeted Minoxidil (MXD) delivery to the follicles and dermal papilla cells (DPCs) could be achieved. Squalene and hexadecyl palmitate (HP) were used as the matrix of the squarticles. The PDGF-squarticles showed a mean diameter and zeta potential of 195 nm and -46 mV, respectively. Nanoparticle encapsulation enhanced MXD porcine skin deposition from 0.11 to 0.23 μg/mg. The antibody-conjugated nanoparticles ameliorated follicular uptake of MXD by 3-fold compared to that of the control solution in the in vivo mouse model. Both vertical and horizontal skin sections exhibited a wide distribution of nanoparticles in the follicles, epidermis, and deeper skin strata. The encapsulated MXD moderately elicited proliferation of DPCs and vascular endothelial growth factor (VEGF) expression. The active targeting of PDGF-squarticles may be advantageous to improving the limited success of alopecia therapy. Topical use of minoxidil is only one of the very few treatment options for alopecia. Nonetheless, the current delivery method is far from ideal. In this article, the authors developed lipid nanocarriers with anti-platelet-derived growth factor receptor ? antibody to target dermal papilla cells, and showed enhanced uptake of minoxidil. Copyright © 2015 Elsevier Inc. All rights reserved.

Utilization of the Tango beta-arrestin recruitment technology for cell-based EDG receptor assay development and interrogation.

PubMed

Wetter, Justin A; Revankar, Chetana; Hanson, Bonnie J

2009-10-01

Cellular assay development for the endothelial differentiation gene (EDG) family of G-protein-coupled receptors (GPCRs) and related lysophospholipid (LP) receptors is complicated by endogenous receptor expression and divergent receptor signaling. Endogenously expressed LP receptors exist in most tissue culture cell lines. These LP receptors, along with other endogenously expressed GPCRs, contribute to off-target signaling that can complicate interpretation of second-messenger-based cellular assay results. These receptors also activate a diverse and divergent set of cellular signaling pathways, necessitating the use of a variety of assay formats with mismatched procedures and functional readouts. This complicates examination and comparison of these receptors across the entire family. The Tango technology uses the conserved beta-arrestin-dependent receptor deactivation process to allow interrogation of the EDG and related receptors with a single functional assay. This method also isolates the target receptor signal, allowing the use of tissue culture cell lines regardless of their endogenous receptor expression. The authors describe the use of this technique to build cell-based receptor-specific assays for all 8 members of the EDG receptor family as well as the related LPA receptors GPR23, GPR92, and GPR87. In addition, they demonstrate the value of this technology for identification and investigation of functionally selective receptor compounds as demonstrated by the immunosuppressive compound FtY720-P and its action at the EDG(1) and EDG(3) receptors.

Recent Progress in the Design and Discovery of RXR Modulators Targeting Alternate Binding Sites of the Receptor.

PubMed

Su, Ying; Zeng, Zhiping; Chen, Ziwen; Xu, Dan; Zhang, Weidong; Zhang, Xiao-Kun

2017-01-01

Retinoid X receptors (RXRs) occupy a central position within the nuclear receptor superfamily. They not only function as important transcriptional factors but also exhibit diverse nongenomic biological activities. The pleiotropic actions of RXRs under both physiological and pathophysiological conditions confer RXRs important drug targets for the treatment of cancer, and metabolic and neurodegenerative diseases. RXR modulators have been studied for the purpose of developing both drug molecules and chemical tools for biological investigation of RXR. Development of RXR modulators has focused on small molecules targeting the canonical ligand-binding pocket. However, accumulating results have demonstrated that there are other binding mechanisms by which small molecules interact with RXR to act as RXR modulators. This review discusses the recent development in the design and discovery of RXR modulators with a focus on those targeting novel binding sites on RXR.

Physicochemical and functional properties of gelatin extracted from Yak skin.

PubMed

Xu, Mengqi; Wei, Lixin; Xiao, Yuancan; Bi, Hongtao; Yang, Hongxia; Du, Yuzhi

2017-02-01

Different molecular weight distribution (MWD) gelatin was extracted from Yak skin after enzymatic pretreatments and their physicochemical and functional properties (SDS-PAGE, UV-vis absorption spectra, DSC, FT-IR, Amino acid analysis, AFM, emulsibility and foamability) were analyzed. The gelatin was extracted by pepsin and got different MWD of Yak skin gelatin by controlling the enzymolysis time. The SDS-PAGE showed the MWD of the Yak skin gelatin. The UV-vis absorption turned out that the broad MWD of Yak skin gelatin had a higher maximum absorption peaks. The FT-IR and AFM indicated that the gelatin structures and microstructures changed with the change of the MWD. The broad MWD of the Yak skin gelatin had a higher denaturation temperature (T D ), and it was higher than most of the other mammals and marine biological gelatin. The broad MWD gelatin also had higher imino acids (proline and hydroxyproline) contents and lower foamability and emulsibility compared to the narrow MWD gelatin. These findings, obtained for the first time for Yak skin gelatin, showed that it has great potential for application as an alternative to commercial gelatin due to its good thermotolerance, particularly in the applications of the biological materials, stabilizer of thermo-tolerant and so on. Copyright © 2016 Elsevier B.V. All rights reserved.

Fibroblast growth factor receptor signaling crosstalk in skeletogenesis.

PubMed

Miraoui, Hichem; Marie, Pierre J

2010-11-02

Fibroblast growth factors (FGFs) play important roles in the control of embryonic and postnatal skeletal development by activating signaling through FGF receptors (FGFRs). Germline gain-of-function mutations in FGFR constitutively activate FGFR signaling, causing chondrocyte and osteoblast dysfunctions that result in skeletal dysplasias. Crosstalk between the FGFR pathway and other signaling cascades controls skeletal precursor cell differentiation. Genetic analyses revealed that the interplay of WNT and FGFR1 determines the fate and differentiation of mesenchymal stem cells during mouse craniofacial skeletogenesis. Additionally, interactions between FGFR signaling and other receptor tyrosine kinase networks, such as those mediated by the epidermal growth factor receptor and platelet-derived growth factor receptor α, were associated with excessive osteoblast differentiation and bone formation in the human skeletal dysplasia called craniosynostosis, which is a disorder of skull development. We review the roles of FGFR signaling and its crosstalk with other pathways in controlling skeletal cell fate and discuss how this crosstalk could be pharmacologically targeted to correct the abnormal cell phenotype in skeletal dysplasias caused by aberrant FGFR signaling.

Selective redox regulation of cytokine receptor signaling by extracellular thioredoxin-1

PubMed Central

Schwertassek, Ulla; Balmer, Yves; Gutscher, Marcus; Weingarten, Lars; Preuss, Marc; Engelhard, Johanna; Winkler, Monique; Dick, Tobias P

2007-01-01

The thiol-disulfide oxidoreductase thioredoxin-1 (Trx1) is known to be secreted by leukocytes and to exhibit cytokine-like properties. Extracellular effects of Trx1 require a functional active site, suggesting a redox-based mechanism of action. However, specific cell surface proteins and pathways coupling extracellular Trx1 redox activity to cellular responses have not been identified so far. Using a mechanism-based kinetic trapping technique to identify disulfide exchange interactions on the intact surface of living lymphocytes, we found that Trx1 catalytically interacts with a single principal target protein. This target protein was identified as the tumor necrosis factor receptor superfamily member 8 (TNFRSF8/CD30). We demonstrate that the redox interaction is highly specific for both Trx1 and CD30 and that the redox state of CD30 determines its ability to engage the cognate ligand and transduce signals. Furthermore, we confirm that Trx1 affects CD30-dependent changes in lymphocyte effector function. Thus, we conclude that receptor–ligand signaling interactions can be selectively regulated by an extracellular redox catalyst. PMID:17557078

Effect of egg albumen protein addition on physicochemical properties and nanostructure of gelatin from fish skin.

PubMed

Cai, Luyun; Feng, Jianhui; Peng, Xichun; Regenstein, Joe M; Li, Xiuxia; Li, Jianrong; Zhao, Wei

2016-12-01

The physicochemical properties and nanostructure of mixtures of egg albumen protein (EAP) and gelatin from under-utilised grass carp ( Ctenopharyngodon idella ) skins were studied. The gelatin with 1% EAP had an acceptable gel strength. The addition of 5% EAP significantly increased the melting and gelling temperatures of gelatin gels. Additionally, the colour turned white and the crystallinity was higher in gelatin gels with gradient concentrations of EAP (1, 3, and 5%). Gelatin with 5% EAP had the highest G' values while gelatin with 1% EAP had the lowest G' values. Atomic force microscopy showed the heterogeneous nanostructure of fish gelatin, and a simple coacervate with a homogeneous distribution was only observed with the addition of 1% EAP, indicating interaction between gelatin and EAP. These results showed that EAP effect fish gelatin's physicochemical and nanostructure properties and has potential applications in foods and pharmaceuticals.

The Epidermal Growth Factor Receptor Critically Regulates Endometrial Function during Early Pregnancy

PubMed Central

Large, Michael J.; Wetendorf, Margeaux; Lanz, Rainer B.; Hartig, Sean M.; Creighton, Chad J.; Mancini, Michael A.; Kovanci, Ertug; Lee, Kuo-Fen; Threadgill, David W.; Lydon, John P.; Jeong, Jae-Wook; DeMayo, Francesco J.

2014-01-01

Infertility and adverse gynecological outcomes such as preeclampsia and miscarriage represent significant female reproductive health concerns. The spatiotemporal expression of growth factors indicates that they play an important role in pregnancy. The goal of this study is to define the role of the ERBB family of growth factor receptors in endometrial function. Using conditional ablation in mice and siRNA in primary human endometrial stromal cells, we identified the epidermal growth factor receptor (Egfr) to be critical for endometrial function during early pregnancy. While ablation of Her2 or Erbb3 led to only a modest reduction in litter size, mice lacking Egfr expression are severely subfertile. Pregnancy demise occurred shortly after blastocyst implantation due to defects in decidualization including decreased proliferation, cell survival, differentiation and target gene expression. To place Egfr in a genetic regulatory hierarchy, transcriptome analyses was used to compare the gene signatures from mice with conditional ablation of Egfr, wingless-related MMTV integration site 4 (Wnt4) or boneless morphogenic protein 2 (Bmp2); revealing that not only are Bmp2 and Wnt4 key downstream effectors of Egfr, but they also regulate distinct physiological functions. In primary human endometrial stromal cells, marker gene expression, a novel high content image-based approach and phosphokinase array analysis were used to demonstrate that EGFR is a critical regulator of human decidualization. Furthermore, inhibition of EGFR signaling intermediaries WNK1 and AKT1S1, members identified in the kinase array and previously unreported to play a role in the endometrium, also attenuate decidualization. These results demonstrate that EGFR plays an integral role in establishing the cellular context necessary for successful pregnancy via the activation of intricate signaling and transcriptional networks, thereby providing valuable insight into potential therapeutic targets. PMID:24945252

RNA sequencing-based analysis of gallbladder cancer reveals the importance of the liver X receptor and lipid metabolism in gallbladder cancer

PubMed Central

Zuo, Mingxin; Rashid, Asif; Wang, Ying; Jain, Apurva; Li, Donghui; Behari, Anu; Kapoor, Vinay Kumar; Koay, Eugene J.; Chang, Ping; Vauthey, Jean Nicholas; Li, Yanan; Espinoza, Jaime A.; Roa, Juan Carlos; Javle, Milind

2016-01-01

Gallbladder cancer (GBC) is an aggressive malignancy. Although surgical resection may be curable, most patients are diagnosed at an advanced unresectable disease stage. Cholelithiasis is the major risk factor; however the pathogenesis of the disease, from gallstone cholecystitis to cancer, is still not understood. To understand the molecular genetic underpinnings of this cancer and explore novel therapeutic targets for GBC, we examined the key genes and pathways involved in GBC using RNA sequencing. We performed gene expression analysis of 32 cases of surgically-resected GBC along with normal gallbladder tissue controls. We observed that 519 genes were differentially expressed between GBC and normal GB mucosal controls. The liver X receptor (LXR)/retinoid X receptor (RXR) and farnesoid X receptor (FXR) /RXR pathways were the top canonical pathways involved in GBC. Key genes in these pathways, including SERPINB3 and KLK1, were overexpressed in GBC, especially in female GBC patients. Additionally, ApoA1 gene expression suppressed in GBC as compared with normal control tissues. LXR and FXR genes, known to be important in lipid metabolism also function as tumor suppressors and their down regulation appears to be critical for GBC pathogenesis. LXR agonists may have therapeutic value and as potential therapeutic targets. PMID:27167107

Single Vesicle Analysis of Endocytic Fission on Microtubules In Vitro

PubMed Central

Wolkoff, Allan W.

2016-01-01

Following endocytosis, internalized molecules are found within intracellular vesicles and tubules that move along the cytoskeleton and undergo fission, as demonstrated here using primary cultured rat hepatocytes. Although the use of depolymerizing drugs has shown that the cytoskeleton is not required to segregate endocytic protein, many studies suggest that the cytoskeleton is involved in the segregation of protein in normal cells. To investigate whether cytoskeletal-based movement results in the segregation of protein, we tracked the contents of vesicles during in vitro microscopy assays. These studies showed that the addition of ATP causes fission of endocytic contents along microtubules, resulting in the segregation of proteins that are targeted for different cellular compartments. The plasma membrane proteins, sodium (Na+) taurocholate cotransporting polypeptide (ntcp) and transferrin receptor, segregated from asialoorosomucoid (ASOR), an endocytic ligand that is targeted for degradation. Epidermal growth factor receptor, which is degraded, and the asialoglycoprotein receptor, which remains partially bound to ASOR, segregated less efficiently from ASOR. Vesicles containing ntcp and transferrin receptor had reduced fission in the absence of ASOR, suggesting that fission is regulated to allow proteins to segregate. A single round of fission resulted in 6.5-fold purification of ntcp from ASOR, and 25% of the resulting vesicles were completely depleted of the endocytic ligand. PMID:18284582

Preclinical discovery and development of maraviroc for the treatment of HIV.

PubMed

Veljkovic, Nevena; Vucicevic, Jelica; Tassini, Sabrina; Glisic, Sanja; Veljkovic, Veljko; Radi, Marco

2015-06-01

Maraviroc is a first-in-class antiretroviral (ARV) drug acting on a host cell target (CCR5), which blocks the entry of the HIV virus into the cell. Maraviroc is currently indicated for combination ARV treatment in adults infected only with CCR5-tropic HIV-1. This drug discovery case history focuses on the key studies that led to the discovery and approval of maraviroc, as well as on post-launch clinical reports. The article is based on the data reported in published preclinical and clinical studies, conference posters and on drug package data. The profound understanding of HIV's entry mechanisms has provided a strong biological rationale for targeting the chemokine receptor CCR5. The CCR5-antagonist mariviroc, with its unique mode of action and excellent safety profile, is an important therapeutic option for HIV patients. In general, the authors believe that targeting host factors is a useful approach for combating new and re-emerging transmissible diseases, as well as pathogens that easily become resistant to common antiviral drugs. Maraviroc, offering a potent and safe cellular receptor-mediated pharmacological response to HIV, has paved the way for the development of a new generation of host-targeting antivirals.

Characterization of ovarian clear cell carcinoma using target drug-based molecular biomarkers: implications for personalized cancer therapy.

PubMed

Li, Mengjiao; Li, Haoran; Liu, Fei; Bi, Rui; Tu, Xiaoyu; Chen, Lihua; Ye, Shuang; Cheng, Xi

2017-02-10

It has long been appreciated that different subtypes (serous, clear cell, endometrioid and mucinous) of epithelial ovarian carcinoma (EOC) have distinct pathogenetic pathways. However, clinical management, especially chemotherapeutic regimens, for EOC patients is not subtype specific. Ovarian clear cell carcinoma (CCC) is a rare histological subtype of EOC, which exhibits high rates of recurrence and low chemosensitivity. We assessed potential therapeutic targets for ovarian CCC patients through analyzing the variation of drug-based molecular biomarkers expression between ovarian CCC and high-grade serous carcinoma (HGSC). Seven candidate drug-based molecular biomarkers, human epidermal growth factor receptor (EGFR), human epidermal growth factor receptor-2 (HER2), phosphatase and tensin homolog deleted on chromosome ten (PTEN), aurora kinase A (AURKA), breast cancer susceptibility gene 1 (BRCA1), breast cancer susceptibility gene 2 (BRCA2) and programmed death-ligand 1 (PD-L1) were measured in 96 ovarian CCC and 113 HGSC by immunohistochemistry in paraffin embedded tissues. The relationship between these biomarkers and clinicopathological factors were explored. The expression level of four of the seven drug-based molecular biomarkers was markedly different between HGSC and CCC. High expression levels of HER2 and PD-L1 were more commonly observed in CCC patients (12.6% vs 2.7%, 21.1% vs 11.6%, P = 0.006, 0.064, respectively), while loss of BRCA1 and BRCA2 expression were more frequently occurred in HGSC patients (72.6% vs 54.3%, 89.4% vs 79.8%, P = 0.007, 0.054, respectively). Survival analysis showed that five of seven biomarkers had prognostic values but varied between subtypes. Furthermore, EGFR expressed frequently in CCC patients with endometriosis than in HGSC patients (44.4% vs 8.3%, P = 0.049). AURKA and PD-L1 correlated with the resistance to platinum-based chemotherapy in CCC patients (P = 0.043, 0.028, respectively) while no similar results were observed in HGSC patients. Ovarian CCC showed a markedly different expression map of drug-based molecular biomarkers from HGSC, which suggested a new personalized target therapy in this rare subtype.

New Chimeric Antigen Receptor Design for Solid Tumors

PubMed Central

Wang, Yuedi; Luo, Feifei; Yang, Jiao; Zhao, Chujun; Chu, Yiwei

2017-01-01

In recent years, chimeric antigen receptor (CAR) T-cell therapy has become popular in immunotherapy, particularly after its tremendous success in the treatment of lineage-restricted hematologic cancers. However, the application of CAR T-cell therapy for solid tumors has not reached its full potential because of the lack of specific tumor antigens and inhibitory factors in suppressive tumor microenvironment (TME) (e.g., programmed death ligand-1, myeloid-derived suppressor cells, and transforming growth factor-β). In this review, we include some limitations in CAR design, such as tumor heterogeneity, indefinite spatial distance between CAR T-cell and its target cell, and suppressive TME. We also summarize some new approaches to overcome these hurdles, including targeting neoantigens and/or multiple antigens at once and depleting some inhibitory factors. PMID:29312360

3D-QSAR studies on 1,2,4-triazolyl 5-azaspiro [2.4]-heptanes as D3R antagonists

NASA Astrophysics Data System (ADS)

Zhang, Xin; Zhang, Hui

2018-07-01

Dopamine D3 receptor has become an attractive target in the treatment of abused drugs. 3D-QSAR studies were performed on a novel series of D3 receptor antagonists, 1,2,4-triazolyl 5-azaspiro [2.4]-heptanes, using CoMFA and CoMSIA methods. Two predictive 3D-QSAR models have been generated for the modified design of D3R antagonists. Based on the steric, electrostatic, hydrophobic and hydrogen-bond acceptor information of contour maps, key structural factors affecting the bioactivity were explored. This work gives helpful suggestions on the design of novel D3R antagonists with increased activities.

The Development of Novel Recombinant Human Gelatins as Replacements for Animal-Derived Gelatin in Pharmaceutical Applications

NASA Astrophysics Data System (ADS)

Olsen, David; Chang, Robert; Williams, Kim E.; Polarek, James W.

We have developed a recombinant expression system to produce a series of novel recombinant human gelatins that can substitute for animal sourced gelatin preparations currently used in pharmaceutical and nutraceutical applications. This system allows the production of human sequence gelatins, or, if desired, gelatins from any other species depending on the availability of the cloned gene. The gelatins produced with this recombinant system are of defined molecular weight, unlike the animal-sourced gelatins, which consist of numerous polypeptides of varying size. The fermentation and purification process used to prepare these recombinant gelatins does not use any human- or animal-derived components and thus this recombinant material should be free from viruses and agents that cause transmissible spongiform encephalopathies. The recombinant gelatins exhibit lot-to-lot reproducibility and we have performed extensive analytical testing on them. We have demonstrated the utility of these novel gelatins as biological stabilizers and plasma expanders, and we have shown they possess qualities that are important in applications where gel formation is critical. Finally, we provide examples of how our system allows the engineering of these recombinant gelatins to optimize the production process.

Accounting for pharmacokinetic differences in dual-tracer receptor density imaging

PubMed Central

Tichauer, K M; Diop, M; Elliott, J T; Samkoe, K S; Hasan, T; St. Lawrence, K; Pogue, B W

2014-01-01

Dual-tracer molecular imaging is a powerful approach to quantify receptor expression in a wide range of tissues by using an untargeted tracer to account for any nonspecific uptake of a molecular-targeted tracer. This approach has previously required the pharmacokinetics of the receptor-targeted and untargeted tracers to be identical, requiring careful selection of an ideal untargeted tracer for any given targeted tracer. In this study, methodology capable of correcting for tracer differences in arterial input functions, as well as binding-independent delivery and retention, is derived and evaluated in a mouse U251 glioma xenograft model using an Affibody tracer targeted to epidermal growth factor receptor (EGFR), a cell membrane receptor overexpressed in many cancers. Simulations demonstrated that blood, and to a lesser extent vascular-permeability, pharmacokinetic differences between targeted and untargeted tracers could be quantified by deconvolving the uptakes of the two tracers in a region of interest devoid of targeted tracer binding, and therefore corrected for, by convolving the uptake of the untargeted tracer in all regions of interest by the product of the deconvolution. Using fluorescently labelled, EGFR-targeted and untargeted Affibodies (known to have different blood clearance rates), the average tumor concentration of EGFR in 4 mice was estimated using dual-tracer kinetic modelling to be 3.9 ± 2.4 nM compared to an expected concentration of 2.0 ± 0.4 nM. However, with deconvolution correction a more equivalent EGFR concentration of 2.0 ± 0.4 nM was measured. PMID:24743262

Receptor-Targeted Nipah Virus Glycoproteins Improve Cell-Type Selective Gene Delivery and Reveal a Preference for Membrane-Proximal Cell Attachment.

PubMed

Bender, Ruben R; Muth, Anke; Schneider, Irene C; Friedel, Thorsten; Hartmann, Jessica; Plückthun, Andreas; Maisner, Andrea; Buchholz, Christian J

2016-06-01

Receptor-targeted lentiviral vectors (LVs) can be an effective tool for selective transfer of genes into distinct cell types of choice. Moreover, they can be used to determine the molecular properties that cell surface proteins must fulfill to act as receptors for viral glycoproteins. Here we show that LVs pseudotyped with receptor-targeted Nipah virus (NiV) glycoproteins effectively enter into cells when they use cell surface proteins as receptors that bring them closely enough to the cell membrane (less than 100 Å distance). Then, they were flexible in receptor usage as demonstrated by successful targeting of EpCAM, CD20, and CD8, and as selective as LVs pseudotyped with receptor-targeted measles virus (MV) glycoproteins, the current standard for cell-type specific gene delivery. Remarkably, NiV-LVs could be produced at up to two orders of magnitude higher titers compared to their MV-based counterparts and were at least 10,000-fold less effectively neutralized than MV glycoprotein pseudotyped LVs by pooled human intravenous immunoglobulin. An important finding for NiV-LVs targeted to Her2/neu was an about 100-fold higher gene transfer activity when particles were targeted to membrane-proximal regions as compared to particles binding to a more membrane-distal epitope. Likewise, the low gene transfer activity mediated by NiV-LV particles bound to the membrane distal domains of CD117 or the glutamate receptor subunit 4 (GluA4) was substantially enhanced by reducing receptor size to below 100 Å. Overall, the data suggest that the NiV glycoproteins are optimally suited for cell-type specific gene delivery with LVs and, in addition, for the first time define which parts of a cell surface protein should be targeted to achieve optimal gene transfer rates with receptor-targeted LVs.