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Targeted Delivery of Paclitaxel to EphA2-Expressing Cancer Cells  

PubMed Central

Purpose YSA is an EphA2-targeting peptide that effectively delivers anti-cancer agents to prostate cancer tumors (1). Here, we report on how we increased the drug-like properties of this delivery system. Experimental Design By introducing non-natural amino acids, we have designed two new EphA2 targeting peptides: YNH, where norleucine and homoserine replace the two methionine residues of YSA, and dYNH, where a D-tyrosine replaces the L-tyrosine at the first position of the YNH peptide. We describe the details of the synthesis of YNH and dYNH paclitaxel conjugates (YNH-PTX and dYNH-PTX) and their characterization in cells and in vivo. Results dYNH-PTX showed improved stability in mouse serum and significantly reduced tumor size in a prostate cancer xenograft model and also reduced tumor vasculature in a syngeneic orthotopic allograft mouse model of renal cancer compared to vehicle or paclitaxel treatments. Conclusion This study reveals that targeting EphA2 with dYNH drug conjugates could represent an effective way to deliver anti-cancer agents to a variety of tumor types. Translational Relevance Overexpression of the EphA2 positively correlates with tumor malignancy and poor prognosis. For this reason, EphA2 is an attractive target for cancer cell specific drug delivery. In this study, we report on the development of dYNH, an EphA2 targeting peptide that when coupled to paclitaxel (PTX) has favorable pharmacological properties and possesses powerful anti-tumor activity in vivo. dYNH-PTX may allow for an expanded therapeutic index of paclitaxel as well as precluding the need for complex formulations and long infusion times. PMID:23155185

Wang, Si; Noberini, Roberta; Stebbins, John L.; Das, Swadesh; Zhang, Ziming; Wu, Bainan; Mitra, Sayantan; Billet, Sandrine; Fernandez, Ana; Bhowmick, Neil A.; Kitada, Shinichi; Pasquale, Elena B.; Fisher, Paul B.; Pellecchia, Maurizio



Novel thermo-sensitive core-shell nanoparticles for targeted paclitaxel delivery  

NASA Astrophysics Data System (ADS)

Novel thermo-sensitive nanoparticles self-assembled from poly(N,N-diethylacrylamide- co-acrylamide)-block-poly(?-benzyl L-glutamate) were designed for targeted drug delivery in localized hyperthermia. The lower critical solution temperature (LCST) of nanoparticles was adjusted to a level between physiological body temperature (37 °C) and that used in local hyperthermia (about 43 °C). The temperature-dependent performances of the core-shell nanoparticles were systemically studied by nuclear magnetic resonance (NMR), circular dichroism (CD), fluorescence spectroscopy, dynamic light scattering (DLS), and atom force microscopy (AFM). The mean diameter of the nanoparticles increased slightly from 110 to 129 nm when paclitaxel (PTX), a poorly water-soluble anti-tumor drug, was encapsulated. A stability study in bovine serum albumin (BSA) solution indicated that the PTX loaded nanoparticles may have a long circulation time under physiological environments as the LCST was above physiological body temperature and the shell remained hydrophilic at 37 °C. The PTX release profiles showed thermo-sensitive controlled behavior. The proliferation inhibiting activity of PTX loaded nanoparticles was evaluated against Hela cells in vitro, compared with Taxol (a formulation of paclitaxel dissolved in Cremophor EL and ethanol). The cytotoxicity of PTX loaded nanoparticles increased obviously when hyperthermia was performed. The nanoparticles synthesized here could be an ideal candidate for thermal triggered anti-tumor PTX delivery system.

Li, Yuanpei; Pan, Shirong; Zhang, Wei; Du, Zhuo



Targeting stents with local delivery of paclitaxel-loaded magnetic nanoparticles using uniform fields  

PubMed Central

The use of stents for vascular disease has resulted in a paradigm shift with significant improvement in therapeutic outcomes. Polymer-coated drug-eluting stents (DES) have also significantly reduced the incidence of reobstruction post stenting, a disorder termed in-stent restenosis. However, the current DESs lack the capacity for adjustment of the drug dose and release kinetics to the disease status of the treated vessel. We hypothesized that these limitations can be addressed by a strategy combining magnetic targeting via a uniform field-induced magnetization effect and a biocompatible magnetic nanoparticle (MNP) formulation designed for efficient entrapment and delivery of paclitaxel (PTX). Magnetic treatment of cultured arterial smooth muscle cells with PTX-loaded MNPs caused significant cell growth inhibition, which was not observed under nonmagnetic conditions. In agreement with the results of mathematical modeling, significantly higher localization rates of locally delivered MNPs to stented arteries were achieved with uniform-field–controlled targeting compared to nonmagnetic controls in the rat carotid stenting model. The arterial tissue levels of stent-targeted MNPs remained 4- to 10-fold higher in magnetically treated animals vs. control over 5 days post delivery. The enhanced retention of MNPs at target sites due to the uniform field-induced magnetization effect resulted in a significant inhibition of in-stent restenosis with a relatively low dose of MNP-encapsulated PTX (7.5 ?g PTX/stent). Thus, this study demonstrates the feasibility of site-specific drug delivery to implanted magnetizable stents by uniform field-controlled targeting of MNPs with efficacy for in-stent restenosis. PMID:20404175

Chorny, Michael; Fishbein, Ilia; Yellen, Benjamin B.; Alferiev, Ivan S.; Bakay, Marina; Ganta, Srinivas; Adamo, Richard; Amiji, Mansoor; Friedman, Gary; Levy, Robert J.



Tumor Angiogenesis Therapy Using Targeted Delivery of Paclitaxel to the Vasculature of Breast Cancer Metastases  

PubMed Central

Breast cancer aberrantly expresses tissue factor (TF) in cancer tissues and cancer vascular endothelial cells (VECs). TF plays a central role in cancer angiogenesis, growth, and metastasis and, as such, is a target for therapy and drug delivery. TF is the cognate receptor of factor VIIa (fVIIa). We have coupled PTX (paclitaxel, also named Taxol) with a tripeptide, phenylalanine-phenylalanine-arginine chloromethyl ketone (FFRck) and conjugated it with fVIIa. The key aim of the work is to evaluate the antiangiogenic effects of PTX-FFRck-fVIIa against a PTX-resistant breast cancer cell line. Matrigel mixed with VEGF and MDA-231 was injected subcutaneously into the flank of athymic nude mice. Animals were treated by tail vein injection of the PTX-FFRck-fVIIa conjugate, unconjugated PTX, or PBS. The PTX-FFRck-fVIIa conjugate significantly reduces microvessel density in matrigel (p < 0.01–0.05) compared to PBS and unconjugated PTX. The breast cancer lung metastasis model in athymic nude mice was developed by intravenous injection of MDA-231 cells expressing luciferase. Animals were similarly treated intravenously with the PTX-FFRck-fVIIa conjugate or PBS. The conjugate significantly inhibits lung metastasis as compared to the control, highlighting its potential to antagonize angiogenesis in metastatic carcinoma. In conclusion, PTX conjugated to fVIIa is a promising therapeutic approach for improving selective drug delivery and inhibiting angiogenesis. PMID:25574399

Kisiel, Walter; Lu, Yang J.; Petersen, Lars C.; Ndungu, John M.; Moore, Terry W.; Parker, Ernest T.; Sun, Aiming; Liotta, Dennis C.; El-Rayes, Bassel F.; Brat, Daniel J.; Snyder, James P.; Shoji, Mamoru



Enhanced antitumor effect of novel dual-targeted paclitaxel liposomes  

NASA Astrophysics Data System (ADS)

A novel dual-targeted peptide containing an alpha V integrins specific ligand and a neuropilin-1 specific motif was developed which showed an increased specific targeting affinity to tumors. Active dual-targeted liposomes were then produced with this peptide and exhibited greater binding activity than single-targeted liposomes in vitro. Paclitaxel entrapped in this formulation greatly increased the uptake of paclitaxel in the targeting cells and significantly suppressed the growth of HUVEC and A549 cells compared with general paclitaxel injections (Taxol) and single-targeted paclitaxel liposomes. The treatment of tumor xenograft models with dual-targeted paclitaxel liposomes also resulted in better tumor growth inhibition than any other treatment groups. Therefore, the dual-targeted paclitaxel liposomes prepared in the present study might be a more promising drug for cancer treatment. Furthermore, the dual-targeting approach may produce synergistic effects that can be applied in the development of new targeted drug delivery systems.

Meng, Shuyan; Su, Bo; Li, Wei; Ding, Yongmei; Tang, Liang; Zhou, Wei; Song, Yin; Li, Heyan; Zhou, Caicun



Liprosomes loading paclitaxel for brain-targeting delivery by intravenous administration: In vitro characterization and in vivo evaluation.  


In this study, a lipid-protein nanocomplex (liprosome) was evaluated for its potential use for brain-targeting drug delivery. Liprosome was fabricated with the desolvation-ultrasonication method and characterized in terms of particle size, size distribution, zeta potential, morphology, crystal state of the drug, and in vitro release. The in vivo distribution of paclitaxel loading lipid-protein nanocomplex (PTX-liprosome) and Taxol were compared after i.v. administration in mice. The prepared PTX-liprosome has a high entrapment efficiency (>90%), small particle size (approximately 110nm), and narrow distribution (P.I.<0.2). Transmission electron microscopy (TEM) indicated that liprosome had a spherical multilayer structure. X-ray photoelectron spectroscopy (XPS) showed that the conjugate of PTX and BSA was in the interior of the PTX-liprosome. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) demonstrated that the drug existed in a molecular or amorphous state. Fourier transform infrared spectroscopy (FTIR) suggested that the hydrophobic interactions, electrostatic interactions and hydrogen bonds among of the PTX, lipid and protein play an important role during the formation of the PTX-liprosome. The hemolysis test showed a good safety profile for the intravenous administration of liprosome. The result of the in vivo distribution suggested that liprosome increased the drug uptake by the brain tissue and decreased drug accumulation in non-target organs. Therefore, liprosome is a potential drug delivery system for transporting PTX to the brain. PMID:25218393

Tang, Bo; Fang, Guihua; Gao, Ying; Liu, Yi; Liu, Jinwen; Zou, Meijuan; Cheng, Gang



Paclitaxel Nano-Delivery Systems: A Comprehensive Review  

PubMed Central

Paclitaxel is one of the most effective chemotherapeutic drugs ever developed and is active against a broad range of cancers, such as lung, ovarian, and breast cancers. Due to its low water solubility, paclitaxel is formulated in a mixture of Cremophor EL and dehydrated ethanol (50:50, v/v) a combination known as Taxol. However, Taxol has some severe side effects related to Cremophor EL and ethanol. Therefore, there is an urgent need for the development of alternative Taxol formulations. The encapsulation of paclitaxel in biodegradable and non-toxic nano-delivery systems can protect the drug from degradation during circulation and in-turn protect the body from toxic side effects of the drug thereby lowering its toxicity, increasing its circulation half-life, exhibiting improved pharmacokinetic profiles, and demonstrating better patient compliance. Also, nanoparticle-based delivery systems can take advantage of the enhanced permeability and retention (EPR) effect for passive tumor targeting, therefore, they are promising carriers to improve the therapeutic index and decrease the side effects of paclitaxel. To date, paclitaxel albumin-bound nanoparticles (Abraxane®) have been approved by the FDA for the treatment of metastatic breast cancer and non-small cell lung cancer (NSCLC). In addition, there are a number of novel paclitaxel nanoparticle formulations in clinical trials. In this comprehensive review, several types of developed paclitaxel nano-delivery systems will be covered and discussed, such as polymeric nanoparticles, lipid-based formulations, polymer conjugates, inorganic nanoparticles, carbon nanotubes, nanocrystals, and cyclodextrin nanoparticles. PMID:24163786

Ma, Ping; Mumper, Russell J.



Paclitaxel Nano-Delivery Systems: A Comprehensive Review.  


Paclitaxel is one of the most effective chemotherapeutic drugs ever developed and is active against a broad range of cancers, such as lung, ovarian, and breast cancers. Due to its low water solubility, paclitaxel is formulated in a mixture of Cremophor EL and dehydrated ethanol (50:50, v/v) a combination known as Taxol. However, Taxol has some severe side effects related to Cremophor EL and ethanol. Therefore, there is an urgent need for the development of alternative Taxol formulations. The encapsulation of paclitaxel in biodegradable and non-toxic nano-delivery systems can protect the drug from degradation during circulation and in-turn protect the body from toxic side effects of the drug thereby lowering its toxicity, increasing its circulation half-life, exhibiting improved pharmacokinetic profiles, and demonstrating better patient compliance. Also, nanoparticle-based delivery systems can take advantage of the enhanced permeability and retention (EPR) effect for passive tumor targeting, therefore, they are promising carriers to improve the therapeutic index and decrease the side effects of paclitaxel. To date, paclitaxel albumin-bound nanoparticles (Abraxane®) have been approved by the FDA for the treatment of metastatic breast cancer and non-small cell lung cancer (NSCLC). In addition, there are a number of novel paclitaxel nanoparticle formulations in clinical trials. In this comprehensive review, several types of developed paclitaxel nano-delivery systems will be covered and discussed, such as polymeric nanoparticles, lipid-based formulations, polymer conjugates, inorganic nanoparticles, carbon nanotubes, nanocrystals, and cyclodextrin nanoparticles. PMID:24163786

Ma, Ping; Mumper, Russell J



Engineering erythrocytes as a novel carrier for the targeted delivery of the anticancer drug paclitaxel.  


Paclitaxel (PTX) is formulated in a mixture of Cremophor EL and dehydrated alcohol. The intravenous administration of this formula is associated with a risk of infection and hypersensitivity reactions. The presence of Cremophor EL as a pharmaceutical vehicle contributes to these effects. Therefore, in this study, we used human erythrocytes, instead of Cremophor, as a pharmaceutical vehicle. PTX was loaded into erythrocytes using the preswelling method. Analysis of the obtained data indicates that 148.8 ?g of PTX was loaded/mL erythrocytes, with an entrapment efficiency of 46.36% and a cell recovery of 75.94%. Furthermore, we observed a significant increase in the mean cell volume values of the erythrocytes, whereas both the mean cell hemoglobin and the mean cell hemoglobin concentration decreased following the loading of PTX. The turbulence fragility index values for unloaded, sham-loaded and PTX-loaded erythrocytes were 3, 2, and 1 h, respectively. Additionally, the erythrocyte glutathione level decreased after PTX loading, whereas lipid peroxidation and protein oxidation increased. The release of PTX from loaded erythrocytes followed first-order kinetics, and about 81% of the loaded drug was released into the plasma after 48 h. The results of the present study revealed that PTX was loaded successfully into human erythrocytes with acceptable loading parameters and with some oxidative modification to the erythrocytes. PMID:25061408

Harisa, Gamaleldin I; Ibrahim, Mohamed F; Alanazi, Fars; Shazly, Gamal A



The use of ?-conotoxin ImI to actualize the targeted delivery of paclitaxel micelles to ?7 nAChR-overexpressing breast cancer.  


Alpha7 nicotinic acetylcholine receptor (?7 nAChR), a ligand-gated ion channel, is increasingly emerging as a new tumor target owing to its expression specificity and significancy for cancer. In an attempt to increase the targeted drug delivery to the ?7 nAChR-overexpressing tumors, herein, ?-conotoxin ImI, a disulfide-rich toxin with highly affinity for ?7 nAChR, was modified on the PEG-DSPE micelles (ImI-PMs) for the first time. The DLS, TEM and HPLC detections showed the spherical nanoparticle morphology about 20 nm with negative charge and high drug encapsulation. The ligand modification did not induce significant differences. The immunofluorescence assay confirmed the expression level of ?7 nAChR in MCF-7 cells. In vitro and in vivo experiments demonstrated that the ?7 nAChR-targeted nanomedicines could deliver more specifically and faster into ?7 nAChR-overexpressing MCF-7 cells. Furthermore, fluo-3/AM fluorescence imaging technique indicated that the increased specificity was attributed to the ligand-receptor interaction, and the inducitivity for intracellular Ca(2+) transient by ImI was still remained after modification. Moreover, paclitaxel, a clinical frequently-used anti-tumor drug for breast cancer, was loaded in ImI-modified nanomedicines to evaluate the targeting efficacy. Besides of exhibiting greater cytotoxicity and inducing more cell apoptosis in vitro, paclitaxel-loaded ImI-PMs displayed stronger anti-tumor efficacy in MCF-7 tumor-bearing nu/nu mice. Finally, the active targeting system showed low systemic toxicity and myelosuppression evidenced by less changes in body weight, white blood cells, neutrophilic granulocyte and platelet counts. In conclusion, ?7 nAChR is also a promising target for anti-tumor drug delivery and in this case, ?-conotoxin ImI-modified nanocarrier is a potential delivery system for targeting ?7 nAChR-overexpressing tumors. PMID:25542793

Mei, Dong; Lin, Zhiqiang; Fu, Jijun; He, Bing; Gao, Wei; Ma, Ling; Dai, Wenbing; Zhang, Hua; Wang, Xueqing; Wang, Jiancheng; Zhang, Xuan; Lu, Wanliang; Zhou, Demin; Zhang, Qiang



High cytotoxicity and resistant-cell reversal of novel paclitaxel loaded micelles by enhancing the molecular-target delivery of the drug  

NASA Astrophysics Data System (ADS)

Many antitumor drugs, such as paclitaxel (PTX), are widely used in cancer chemotherapy. However, their clinical use is limited by systemic toxicity, rapid blood clearance, and the occurrence of resistance. To increase the therapeutic index of these drugs, the antitumor drug PTX was encapsulated in novel micelles with glycolipid-like structure, which were formed by stearate grafted chitosan oligosaccharide in aqueous medium. The micelles could load the poorly soluble antitumor drug (PTX) with high entrapment efficiency and drug loading. PTX release was retarded as a result of the encapsulation of the micelles. PTX loaded micelles present excellent internalization into tumor cells as well as resistant cells and subsequently reside in cytoplasm, which results in increased intracellular accumulation of PTX in its molecular-target site. Consequently, cytotoxicity of PTX loaded micelles was improved sharply and resistant cells were reversed. In conclusion, high cytotoxicity can be obtained and resistant cells can be reversed by enhancing PTX's molecular-target delivery and accumulation via the encapsulation of the micelles. The present micelles are a promising carrier candidate for effective therapy of antitumor drugs with the target molecule in cytoplasm.

You, Jian; Hu, Fu-Qiang; Du, Yong-Zhong; Yuan, Hong; Ye, Bang-Fu



Conformationally Constrained and Nanoparticle Targeted Paclitaxels*  

PubMed Central

Paclitaxel (Taxol®) is one of the most important anticancer agents developed over the last 30 years. Its primary mechanism of action is by interaction with the cellular protein tubulin, causing irreversible polymerization to microtubules. A detailed knowledge of this crucial interaction is thus of paramount importance in the design and development of highly potent analogs and also for the potential development of “non-taxane” tubulin polymerization agents. This review briefly describes the discovery and development of taxol, and then describes our work on delineating the tubulin-binding conformation of paclitaxel by a combination of REDOR NMR and molecular modeling. The resulting “T-taxol” conformation was validated by the synthesis of conformationally constrained paclitaxel analogs, which had bioactivities up to twenty-fold higher than those of paclitaxel. The review concludes with recent work on the development of a gold nanoparticle derivative of paclitaxel. This delivery method has the potential to lower the dosage of paclitaxel needed while maintaining or increasing its effectiveness, thus significantly improving the benefits of this important chemotherapeutic agent.

Tamarkin, Lawrence; Paciotti, Giulio F.



Tumor-Targeted Paclitaxel Delivery and Enhanced Penetration Using TAT-Decorated Liposomes Comprising Redox-Responsive Poly(Ethylene Glycol).  


To combine the advantage of poly(ethylene gylcol) (PEG) for longer circulation and cell-penetrating peptides (CPPs) for efficient cellular uptake, paclitaxel (PTX)-loaded liposomes functionalized with TAT, the most frequently used CPP, and cleavable PEG via a redox-responsive disulfide linker (PTX-C-TAT-LP) were successfully developed here. Under physiological conditions, TAT was shielded by PEG layer and liposomes exhibited a long blood circulation. At tumor site, PEG could be detached in the presence of exogenous reducing agent [glutathione (GSH)] and TAT was exposed to facilitate cell internalization. In the presence of GSH, the liposomal vesicle C-TAT-LP showed increased cellular uptake and improved three-dimensional tumor spheroids penetration in vitro compared with analogous stable shielded liposomes. C-TAT-LP achieved enhanced tumor distribution and demonstrated superior delivery efficiency in vivo. PTX-C-TAT-LP with GSH strongly inhibited the proliferation of murine melanoma B16F1 tumor cells in vitro and in vivo with the tumor inhibition rate being 69.4% on B16F1-bearing mice. In addition, the serum aspartate transaminase level, alanine transaminase level, and creatine kinase level were almost completely within normal range in the PTX-C-TAT-LP with GSH group, revealing PTX-C-TAT-LP with GSH had no obvious drug-related adverse events for liver and heart. Taken together, C-TAT-LP is a promising tumor-targeting drug carrier. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:1160-1173, 2015. PMID:25449709

Fu, Han; Shi, Kairong; Hu, Guanlian; Yang, Yuting; Kuang, Qifang; Lu, Libao; Zhang, Li; Chen, Wenfei; Dong, Mingling; Chen, Yantao; He, Qin



Doxorubicin and paclitaxel loaded microbubbles for ultrasound triggered drug delivery  

PubMed Central

A polymer ultrasound contrast agent (UCA) developed in our lab has been shown to greatly reduce in size when exposed to ultrasound, resulting in nanoparticles less than 400 nm in diameter capable of escaping the leaky vasculature of a tumor to provide a sustained release of drug. Previous studies with the hydrophilic drug doxorubicin (DOX) demonstrated enhanced drug delivery to tumors when triggered with ultrasound. However the therapeutic potential has been limited due to the relatively low payload of DOX. This study compares the effects of loading the hydrophobic drug paclitaxel (PTX) on the agent’s acoustic properties, drug payload, tumoricidal activity, and the ability to deliver drugs through 400 nm pores. A maximum payload of 129.46 ± 1.80 ?g PTX/mg UCA (encapsulation efficiency 71.92 ± 0.99 %) was achieved, 20 times greater than the maximum payload of DOX (6.2 ?g/mg), while maintaining the acoustic properties. In vitro, the tumoricidal activity of paclitaxel loaded UCA exposed to ultrasound was significantly greater than controls not exposed to ultrasound (p<0.0016). This study has shown that PTX loaded UCA triggered with focused ultrasound have the potential to provide a targeted and sustained delivery of drug to tumors. PMID:21609756

Cochran, Michael C.; Eisenbrey, John; Ouma, Richard O.; Soulen, Michael; Wheatley, Margaret A.



Designing Paclitaxel Drug Delivery Systems Aimed at Improved Patient Outcomes: Current Status and Challenges  

PubMed Central

Paclitaxel is one of the most widely used and effective antineoplastic agents derived from natural sources. It has a wide spectrum of antitumor activity, particularly against ovarian cancer, breast cancer, nonsmall cell lung cancer, head and neck tumors, Kaposi's sarcoma, and urologic malignancies. It is a highly lipophilic compound with a log P value of 3.96 and very poor aqueous solubility of less than 0.01?mg/mL. In addition, the compound lacks functional groups that are ionizable which could potentially lead to an increase in its solubility with the alteration in pH. Therefore, the delivery of paclitaxel is associated with substantial challenges. Until the introduction of Abraxane, only commercial formulation was solution of paclitaxel in cremophor, which caused severe side effects. However, in recent years, a number of approaches have been reported to solubilize paclitaxel using cosolvents and inclusion complexes. In addition, innovative approaches have been reported for passive targeting of tumors using nanoparticles, nanosuspensions, liposomes, emulsions, micelles, implants, pastes and gels. All approaches for delivery of improved therapeutic outcome have been discussed in this paper. PMID:22934190

Surapaneni, Madhu S.; Das, Sudip K.; Das, Nandita G.



Polymeric nanoparticles for the intracellular delivery of paclitaxel in lung and breast cancer  

NASA Astrophysics Data System (ADS)

Nanoparticles are useful for addressing many of the difficulties encountered when administering therapeutic compounds. Nanoparticles are able to increase the solubility of hydrophobic drugs, improve pharmacokinetics through sustained release, alter biodistribution, protect sensitive drugs from low pH environments or enzymatic alteration, and, in some cases, provide targeting of the drug to the desired tissues. The use of functional nanocarriers can also provide controlled intracellular delivery of a drug. To this end, we have developed functional pH-responsive expansile nanoparticles for the intracellular delivery of paclitaxel. The pH-responsiveness of these nanoparticles occurs due to a hydrophobic to hydrophilic transition of the polymer occurring under mildly acidic conditions. These polymeric nanoparticles were systematically evaluated for the delivery of paclitaxel in vitro and in vivo to improve local therapy for lung and breast cancers. Nanoparticles were synthesized using a miniemulsion polymerization process and were subsequently characterized and found to swell when exposed to acidic environments. Paclitaxel was successfully encapsulated within the nanoparticles, and the particles exhibited drug release at pH 5 but not at pH 7.4. In addition, the uptake of nanoparticles was observed using flow cytometry, and the anticancer efficacy of the paclitaxel-loaded nanoparticles was measured using cancer cell lines in vitro. The potency of the paclitaxel-loaded nanoparticles was close to that of free drug, demonstrating that the drug was effectively delivered by the particles and that the particles could act as an intracellular drug depot. Following in vitro characterization, murine in vivo studies demonstrated the ability of the paclitaxel-loaded responsive nanoparticles to delay recurrence of lung cancer and to prevent establishment of breast cancer in the mammary fat pads with higher efficacy than paclitaxel alone. In addition, the ability of nanoparticles to migrate up to 40 cm through lymphatic channels to local lymph nodes was demonstrated using near infrared imaging in a large animal model. Continued investigation of functional nanoparticles, like the system described here for lung and breast cancer, will facilitate the development of new materials that meet the varied and demanding needs in chemotherapy, and may afford new treatment options for the local and metastatic control of many forms of cancer.

Zubris, Kimberly Ann Veronica


Carboxymethyl-chitosan-tethered lipid vesicles: hybrid nanoblanket for oral delivery of paclitaxel.  


We describe the development and evaluation of a hybrid lipopolymeric system comprising carboxymethyl chitosan (CMC), covalently tethered to phosphatidylethanolamine units on the surface of lipid nanovesicles, for oral delivery of paclitaxel. The bioploymer is intended to act as a blanket, thereby shielding the drug from harsh gastrointestinal conditions, whereas the lipid nanovesicle ensures high encapsulation efficiency of paclitaxel and its passive targeting to tumor. CMC-tethered nanovesicles (LN-C-PTX) in the size range of 200-300 nm improved the gastrointestinal resistance and mucoadhesion properties as compared with unmodified lipid nanovesicles (LN-PTX). Conjugation of CMC did not compromise the cytotoxic potential of paclitaxel yet facilitated the interaction and uptake of the nanovesicles by murine melanoma (B16F10) cells through an ATP-dependent process. CMC-conjugated nanovesicles, upon oral administration in rats, improved the plasma concentration profile of paclitaxel, with 1.5 fold increase in its bioavailability and 5.5 folds increase in elimination half life in comparison with Taxol. We also found that CMC in addition to providing a gastric resistant coating also imparted stealth character to the nanovesicles, thereby reducing their reticuloendothelial system (RES)-mediated uptake by liver and spleen and bypassing the need for PEGylation. In vivo efficacy in subcutaneous model of B16F10 showed significantly improved tumor growth inhibition and survival with CMC-tethered nanovesicles as compared with unmodified nanovesicles, both administered orally. LN-C-PTX exhibited therapeutic efficacy comparable to Taxol and Abraxane and also showed reduced toxicity and improved survival. Overall, these results suggest the therapeutic potential of CMC tethered nanovesicles as a platform for oral administration of paclitaxel and also unravel the ability of CMC to impart stealth character to the nanoparticles, thereby preventing their RES clearance. PMID:23721348

Joshi, Nitin; Saha, Rama; Shanmugam, Thanigaivel; Balakrishnan, Biji; More, Prachi; Banerjee, Rinti



Delivery of Paclitaxel Using PEGylated Graphene Oxide as a Nanocarrier.  


Paclitaxel (PTX) is an extensively used potent chemotherapy drug; however, low water solubility, poor bioavailability, and emergence of drug resistance in patients limited its biological application. In this report, we proposed a new drug delivery system for cancer therapy based on graphene oxide (GO), a novel 2D nanomaterial obtained from the oxidation of natural graphite, to improve the utilization rate of PTX. PTX was first connected to biocompatible 6-armed poly(ethylene glycol), followed by covalent introduction into the surface of GO sheets via a facile amidation process under mild conditions, affording the drug delivery system, GO-PEG-PTX (size 50-200 nm). GO-PEG nanosized carrier could quickly enter into human lung cancer A549 and human breast cancer MCF-7 cells verified by inverted fluorescence microscope using fluorescein isothiocyanate as probe. This nanocarrier was nontoxic to A549 and MCF-7 cells without linking with PTX. Nevertheless, GO-PEG-PTX showed remarkably high cytotoxicity to A549 and MCF-7 cells in a broad range of concentration of PTX and time compared to free PTX. This kind of nanoscale drug delivery system based on PEGylated GO may find widespread application in biomedicine. PMID:25546399

Xu, Zhiyuan; Zhu, Shaojia; Wang, Mingwei; Li, Yongjun; Shi, Ping; Huang, Xiaoyu



Nanocarrier-assisted sub-cellular targeting to the site of mitochondria improves the pro-apoptotic activity of paclitaxel.  


Many drug molecules exert their biological action on intracellular molecular targets present on or inside various cellular organelles. Consequently, it has become more evident that the efficiency and efficacy of drug action is dependent largely on how well an unaided drug molecule is able to reach its intracellular target. We hypothesized that the biological action of such drug molecules might be improved by specific delivery to the appropriate sub-cellular site by a pharmaceutical carrier designed for the purpose. To test our hypothesis, we used paclitaxel, a molecule that has recently been shown to have pro-apoptotic biological targets on the mitochondria but has a quantitative structure-activity relationship-predicted cytosolic accumulation and no affinity for mitochondria. Using a mitochondria-specific nanocarrier system (DQAsomes) prepared from the amphiphilic quinolinium derivative dequalinium chloride to deliver paclitaxel to mitochondria in cells, we report that it is possible to improve the pro-apoptotic action of paclitaxel. PMID:18686127

D'Souza, Gerard G M; Cheng, Shing-Ming; Boddapati, Sarathi V; Horobin, Richard W; Weissig, Volkmar



The enhanced longevity and liver targetability of Paclitaxel by hybrid liposomes encapsulating Paclitaxel-conjugated gold nanoparticles.  


Organic and inorganic drug delivery systems both demonstrate their own advantages and challenges in practical applications. Combining these two drug delivery strategies in one system is expected to solve their current issues and achieve desirable functions. In this paper, gold nanoparticles (GNPs) and liposomes have been chosen as the model systems to construct a hybrid system and investigate its performance for the tumor therapy of Paclitaxel (PTX). The thiol-terminated polyethylene glycol (PEG400)-PTX derivative has been covalently modified on the surface of GNPs, followed by the encapsulation of PTX-conjugated GNPs (PTX-PEG400@GNPs) in liposomes. The hybrid liposomes solve the solubility and stability problems of gold conjugates and show high drug loading capacity. In vitro PTX release from the hybrid system maintains the similar sustained behavior demonstrated in its conjugates. Under the protection of a biocompatible liposome shell, encapsulated PTX shows enhanced circulation longevity and liver targetability compared to Taxol(®) and PTX-PEG400@GNPs suspension in the pharmacokinetic and biodistribution studies. These indicate that encapsulating drug-conjugated inorganic nanoparticles inside organic carriers maintains the superiority of both vehicles and improves the performance of hybrid systems. Although these attributes of hybrid liposomes lead to a better therapeutic capacity in a murine liver cancer model than that of the comparison groups, it shows no significant difference from Taxol(®) and conjugate suspension. This result could be due to the delayed and sustained drug release from the system. However, it indicates the promising potential for these hybrid liposomes will allow further construction of a compound preparation with improved performance that is based on their enhanced longevity and liver targetability of Paclitaxel. PMID:25455782

Bao, Quan-Ying; Zhang, Ning; Geng, Dong-Dong; Xue, Jing-Wei; Merritt, Mackenzie; Zhang, Can; Ding, Ya



Paclitaxel Tumor-Priming Enhances siRNA Delivery and Transfection in 3-Dimensional Tumor Cultures  

PubMed Central

The clinical development of siRNA cancer therapeutics is limited by the poor interstitial transport and inefficient transfection in solid tumors. We have shown that paclitaxel pretreatment, by inducing apoptosis, causes expansion of the interstitial space and thereby improves nanoparticle delivery and transport in tumor interstitium (referred to as paclitaxel tumor priming) and efficacy of nanomedicines in tumor-bearing animals. The present study evaluated whether paclitaxel tumor priming improves the delivery and transfection of siRNA in 2- and 3-dimensional cultures of human oropharyngeal carcinoma FaDu cells. We used the fluorescent siGLO and confocal microcopy to monitor transport, and used survivin siRNA and immunostaining and immunoblotting to monitor transfection. Survivin is a chemoresistance gene/protein, inducible by chemotherapy. siRNA was loaded in cationic liposomes. The results showed that pretreatment with 50-200 nM paclitaxel (24 or 48 hr before siRNA) enhanced the total uptake of siGLO into monolayers (~15%, p<0.05), and the depth of penetration into 3-dimensional spheroids and tumor fragment histocultures (2.1- to 2.5-times greater area under the penetration-depth curve). In both monolayer cells and histocultures, paclitaxel pretreatment induced survivin upregulation (p<0.05). Survivin siRNA alone decreased the survivin levels in a dose-dependent manner and applying survivin siRNA after paclitaxel pretreatment completely abolished the paclitaxel-induced survivin increases. These findings indicate that paclitaxel tumor priming did not compromise the siRNA functionality. In summary, paclitaxel tumor priming improved the penetration, transfection and functionality of siRNA in tumors, thus offering a promising and practical means to develop chemo-siRNA cancer gene therapy. PMID:21417439

Wong, Ho Lun; Shen, Zancong; Lu, Ze; Wientjes, M. Guillaume; Au, Jessie L.-S.



Sulfatide-containing lipid perfluorooctylbromide nanoparticles as paclitaxel vehicles targeting breast carcinoma  

PubMed Central

Targeted nanoparticle (NP) delivery vehicles are emerging technologies, the full potential of which has yet to be realized. Sulfatide is known to bind to extracellular matrix glycoproteins that are highly expressed in breast tumors. In this study, we report for the first time the combination of sulfatide and lipid perfluorooctylbromide NPs as a targeted breast cancer delivery vehicle for paclitaxel (PTX). PTX-sulfatide-containing lipid perfluorooctylbromide NPs (PTX-SNPs) were prepared using the emulsion/solvent evaporation method. PTX-SNPs exhibited a spherical shape, small particle size, high encapsulation efficiency, and a biphasic release in phosphate-buffered solution. The cytotoxicity study and cell apoptosis assay revealed that blank sulfatide-containing lipid perfluorooctylbromide NPs (SNPs) had no cytotoxicity, whereas PTX-SNPs had greater EMT6 cytotoxicity levels than PTX-lipid perfluorooctylbromide NPs (PTX-NPs) and free PTX. An in vitro cellular uptake study revealed that SNPs can deliver greater amounts of drug with more efficient and immediate access to intracellular targets. In vivo biodistribution measured using high-performance liquid chromatography confirmed that the PTX-SNPs can target breast tumor tissues to increase the accumulation of PTX in these tissues. The in vivo tumor inhibition ability of PTX-SNPs was remarkably higher than PTX-NPs and free PTX. Furthermore, toxicity studies suggested that the blank SNPs had no systemic toxicity. All results suggested that SNPs may serve as efficient PTX delivery vehicles targeting breast carcinoma. PMID:25170267

Li, Xiao; Qin, Fei; Yang, Li; Mo, Liqian; Li, Lei; Hou, Lianbing



Efficient Drug Delivery of Paclitaxel Glycoside: A Novel Solubility Gradient Encapsulation into Liposomes Coupled with Immunoliposomes Preparation  

PubMed Central

Although the encapsulation of paclitaxel into liposomes has been extensively studied, its significant hydrophobic and uncharged character has generated substantial difficulties concerning its efficient encapsulation into the inner water core of liposomes. We found that a more hydrophilic paclitaxel molecule, 7-glucosyloxyacetylpaclitaxel, retained tubulin polymerization stabilization activity. The hydrophilic nature of 7-glucosyloxyacetylpaclitaxel allowed its efficient encapsulation into the inner water core of liposomes, which was successfully accomplished using a remote loading method with a solubility gradient between 40% ethylene glycol and Cremophor EL/ethanol in PBS. Trastuzumab was then conjugated onto the surface of liposomes as immunoliposomes to selectively target human epidermal growth factor receptor-2 (HER2)-overexpressing cancer cells. In vitro cytotoxicity assays revealed that the immunoliposomes enhanced the toxicity of 7-glucosyloxyacetylpaclitaxel in HER2-overexpressing cancer cells and showed more rapid suppression of cell growth. The immunoliposomes strongly inhibited the tumor growth of HT-29 cells xenografted in nude mice. Notably, mice survived when treated with the immunoliposomes formulation, even when administered at a lethal dose of 7-glucosyloxyacetylpaclitaxel in vivo. This data successfully demonstrates immunoliposomes as a promising candidate for the efficient delivery of paclitaxel glycoside. PMID:25264848

Murakami, Masaharu; Sekhar, Sreeja C.; Tominaga, Yuki; Okada, Masashi; Kudoh, Takayuki; Mizutani, Akifumi; Murakami, Hiroshi; Salomon, David S.; Mikuni, Katsuhiko; Mandai, Tadakatsu; Hamada, Hiroki; Seno, Masaharu



Thermosensitive and mucoadhesive sol-gel composites of paclitaxel/dimethyl-?-cyclodextrin for buccal delivery.  


The purpose of this study was to develop a buccal paclitaxel delivery system using the thermosensitive polymer Pluronic F127 (PF127) and the mucoadhesive polymer polyethylene oxide (PEO). The anticancer agent paclitaxel is usually used to treat ovarian, breast, and non-small-cell lung cancer. To improve its aqueous solubility, paclitaxel was incorporated into an inclusion complex with (2,6-di-O-methyl)-?-cyclodextrin (DM?CD). The formation of the paclitaxel inclusion complex was evaluated using various techniques, including x-ray diffractometry (XRD), Fourier-transform infrared (FT-IR) spectrophotometry, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Hydrogels were prepared using a cold method. Concentrations of 18, 20, and 23% (w/v) PF127 were dissolved in distilled water including paclitaxel and stored overnight in a refrigerator at 4 °C. PEO was added at concentrations of 0.1, 0.2, 0.4, 0.8, and 1% (w/v). Each formulation included paclitaxel (0.5 mg/mL). The sol-gel transition temperature of the hydrogels was measured using the tube-inverting method. Drug release from the hydrogels was measured using a Franz diffusion cell containing pH 7.4 phosphate-buffered solution (PBS) buffer at 37 °C. The cytotoxicity of each formulation was measured using the MTT assay with a human oral cancer cell (KB cell). The sol-gel transition temperature of the hydrogel decreased when PF127 was present and varied according to the presence of mucoadhesive polymers. The in vitro release was sustained and the release rate was slowed by the addition of the mucoadhesive polymer. The cytotoxicity of the blank formulation was low, although the drug-loaded hydrogel showed acceptable cytotoxicity. The results of our study suggest that the combination of a PF 127-based mucoadhesive hydrogel formulation and inclusion complexes improves the in vitro release and cytotoxic effect of paclitaxel. PMID:25275485

Choi, Soon Gil; Lee, Sang-Eun; Kang, Bong-Seok; Ng, Choon Lian; Davaa, Enkhzaya; Park, Jeong-Sook



Neovascular targeting chemotherapy: encapsulation of paclitaxel in cationic liposomes impairs functional tumor microvasculature.  


Cationic liposomes have been shown to be internalized selectively by angiogenic tumor endothelial cells after intravenous injection. Therefore, encapsulation of cytotoxic substances in cationic liposomes is a new approach to target tumor vasculature. It was the aim of our study to quantify the effects of paclitaxel encapsulated in cationic liposomes (MBT-0206) on tumor microvasculature and growth in vivo. Experiments were performed in the dorsal skinfold chamber preparation of Syrian Golden hamsters bearing syngeneic A-Mel-3 melanomas. Tumors were treated with intravenous infusion of MBT-0206 (20 mM) resulting in an effective paclitaxel dose of 5 mg/kg body weight (b.w.). Control animals received conventional paclitaxel in Cremophor EL (Taxol(R); 5 mg/kg b.w.), unloaded cationic liposomes (20 mM) or the solvent 5% glucose, respectively. Using intravital microscopy, tumor growth and effects on intratumoral microvasculature were analyzed. Tumor growth was significantly retarded after treatment with MBT-0206 compared to the treatment with paclitaxel. Analysis of intratumoral microcirculation revealed a reduced functional vessel density in tumors after application of liposomal paclitaxel. At the end of the observation time, vessel diameters were significantly smaller in animals treated with paclitaxel encapsulated in cationic liposomes while red blood cell velocity was less affected. This resulted in a significantly reduced blood flow in vessel segments and a reduced microcirculatory perfusion index in these animals. Histochemical TUNEL stain was vessel-associated after treatment with liposomal paclitaxel in contrast to few apoptotic tumor cells in the control groups. Our data demonstrate that encapsulation of paclitaxel in cationic liposomes significantly increased the antitumoral efficacy of the drug. Remarkable microcirculatory changes indicate that encapsulation of paclitaxel in cationic liposomes resulted in a mechanistic switch from tumor cell toxicity to an antivascular therapy. PMID:15054876

Strieth, Sebastian; Eichhorn, Martin E; Sauer, Birgitta; Schulze, Brita; Teifel, Michael; Michaelis, Uwe; Dellian, Marc



Double layer paclitaxel delivery systems based on bioresorbable terpolymer with shape memory properties.  


The growing interest in the bioresorbable polymers contributed to developing a number of commercially available controlled drug delivery systems. Due to a variety of drugs and their physicochemical properties, there is a necessity of choosing an appropriate drug carrier. Terpolymer with shape memory properties was used to obtain double layer matrices composed of drug free matrix and paclitaxel containing layer. The in vitro degradation and drug release study were conducted at 37 °C in PBS (pH 7.4). The investigated materials were characterized by GPC (gel permeation chromatography) and DSC (differential scanning calorimetry). HPLC (high-pressure liquid chromatography) was applied to analyze the amount of released paclitaxel. The main purpose of this work was to determine the usefulness of the studied terpolymer as an anti-restenotic drug vehicle. Based on the obtained results it was established that polymer's degradation proceeded regularly and provided even paclitaxel release profiles. Double layer systems allowed to modify the amount of released drug which may be considered while developing the self-expanding drug-eluting stents tailoring different clinical indications. PMID:24491529

Musia?-Kulik, Monika; Kasperczyk, Janusz; Smola, Anna; Dobrzy?ski, Piotr



Improved Biochemical Strategies for Targeted Delivery of Taxoids  

PubMed Central

Paclitaxel (Taxol ®) and docetaxel (Taxotere ®) are very important anti-tumor drugs in clinical use for cancer. However, their clinical utility is limited due to systemic toxicity, low solubility and inactivity against drug resistant tumors. To improve chemotherapeutic levels of these drugs, it would be highly desirable to design strategies which bypass the above limitations. In this respect various prodrug and drug targeting strategies have been envisioned either to improve oral bioavailability or tumor specific delivery of taxoids. Abnormal properties of cancer cells with respect to normal cells have guided in designing of these protocols. This review article records the designed biochemical strategies and their biological efficacies as potential taxoid chemotherapeutics. PMID:17419065

Ganesh, Thota



Facile preparation of paclitaxel loaded silk fibroin nanoparticles for enhanced antitumor efficacy by locoregional drug delivery.  


Non-toxic, safe materials and preparation methods are among the most important factors when designing nanoparticles (NPs) for future clinical application. Here we report a novel and facile method encapsulating anticancer drug paclitaxel (PTX) into silk fibroin (SF), a biocompatible and biodegradable natural polymer, without adding any toxic organic solvents, surfactants or other toxic agents. The paclitaxel loaded silk fibroin nanoparticles (PTX-SF-NPs) with a diameter of 130 nm were formed in an aqueous solution at room temperature by self-assembling of SF protein, which demonstrated mainly silk I conformation in the NPs. In cellular uptake experiments, coumarin-6 loaded SF NPs were taken up efficiently by two human gastric cancer cell lines BGC-823 and SGC-7901. In vitro cytotoxicity studies demonstrated that PTX kept its pharmacological activity when incorporating into PTX-SF-NPs, while SF showed no cytotoxicity to cells. The in vivo antitumor effects of PTX-SF-NPs were evaluated on gastric cancer nude mice exnograft model. We found that locoregional delivery of PTX-SF-NPs demonstrated superior antitumor efficacy by delaying tumor growth and reducing tumor weights compared with systemic administration. Furthermore, the organs of mice in NP treated groups didn't show obvious toxicity, indicating the in vivo safety of SF NPs. These results suggest that SF NPs are promising drug delivery carriers, and locoregional delivery of SF NPs could be a potential future clinical cancer treatment regimen. PMID:24274601

Wu, Puyuan; Liu, Qin; Li, Rutian; Wang, Jing; Zhen, Xu; Yue, Guofeng; Wang, Huiyu; Cui, Fangbo; Wu, Fenglei; Yang, Mi; Qian, Xiaoping; Yu, Lixia; Jiang, Xiqun; Liu, Baorui



In vivo prevention of arterial restenosis with paclitaxel-encapsulated targeted lipid–polymeric nanoparticles  

PubMed Central

Following recent successes with percutaneous coronary intervention (PCI) for treating coronary artery disease (CAD), many challenges remain. In particular, mechanical injury from the procedure results in extensive endothelial denudation, exposing the underlying collagen IV-rich basal lamina, which promotes both intravascular thrombosis and smooth muscle proliferation. Previously, we reported the engineering of collagen IV-targeting nanoparticles (NPs) and demonstrated their preferential localization to sites of arterial injury. Here, we develop a systemically administered, targeted NP system to deliver an antiproliferative agent to injured vasculature. Approximately 60-nm lipid–polymeric NPs were surface functionalized with collagen IV-targeting peptides and loaded with paclitaxel. In safety studies, the targeted NPs showed no signs of toxicity and a ?3.5-fold improved maximum tolerated dose versus paclitaxel. In efficacy studies using a rat carotid injury model, paclitaxel (0.3 mg/kg or 1 mg/kg) was i.v. administered postprocedure on days 0 and 5. The targeted NP group resulted in lower neointima-to-media (N/M) scores at 2 wk versus control groups of saline, paclitaxel, or nontargeted NPs. Compared with sham-injury groups, an ?50% reduction in arterial stenosis was observed with targeted NP treatment. The combination of improved tolerability, sustained release, and vascular targeting could potentially provide a safe and efficacious option in the management of CAD. PMID:22087004

Chan, Juliana M.; Drum, Chester L.; Bronson, Roderick T.; Golomb, Gershon; Langer, Robert; Farokhzad, Omid C.



Excipient effects on in vitro cytotoxicity of a novel paclitaxel self-emulsifying drug delivery system.  


Paclitaxel is a potent chemotherapeutic agent currently administered intravenously in polyoxyethylated castor oil (Cremophor EL) and dehydrated ethanol (1:1) for the treatment of solid tumors. The objective of this work was to develop a novel self-emulsifying drug delivery system (SEDDS) devoid of cremophor for the i.v./oral delivery of paclitaxel and to investigate the in vitro cytotoxicity of the combined excipients. The SEDDS formulations were characterized in terms of droplet size using a ternary phase diagram. The Caco-2 cell line was used to monitor the cytotoxicity of the excipients. Cell viability was determined colorimetrically at 570 nm utilizing the MTT assay. The distribution of the formulations on the phase diagram indicated the presence of macroemulsions ( approximately 1 microm), submicron emulsions (50-200 nm), and microemulsions (below 10 nm). An increase in the sodium deoxycholate excipient content led to an increase in physical stability but caused more chemical degradation of the drug and more cytotoxicity. The drug in the novel SEDDS was chemically stable for at least 1 year when kept as a two-part formulation. The drug loading was increased by approximately fivefold compared to the marketed i.v. formulation; the excipients presented a significantly reduced cytotoxicity and led to a stable microemulsion. PMID:14603486

Gursoy, Neslihan; Garrigue, Jean-Sebastien; Razafindratsita, Alain; Lambert, Gregory; Benita, Simon



Dual Targeting Biomimetic Liposomes for Paclitaxel/DNA Combination Cancer Treatment  

PubMed Central

Combinations of chemotherapeutic drugs with nucleic acid has shown great promise in cancer therapy. In the present study, paclitaxel (PTX) and DNA were co-loaded in the hyaluronic acid (HA) and folate (FA)-modified liposomes (HA/FA/PPD), to obtain the dual targeting biomimetic nanovector. The prepared HA/FA/PPD exhibited nanosized structure and narrow size distributions (247.4 ± 4.2 nm) with appropriate negative charge of ?25.40 ± 2.7 mV. HA/FA/PD (PTX free HA/FA/PPD) showed almost no toxicity on murine malignant melanoma cell line (B16) and human hepatocellular carcinoma cell line (HepG2) (higher than 80% cell viability), demonstrating the safety of the blank nanovector. In comparison with the FA-modified PTX/DNA co-loaded liposomes (FA/PPD), HA/FA/PPD showed significant superiority in protecting the nanoparticles from aggregation in the presence of plasma and degradation by DNase I. Moreover, HA/FA/PPD could also significantly improve the transfection efficiency and cellular internalization rates on B16 cells comparing to that of FA/PPD (p < 0.05) and PPD (p < 0.01), demonstrating the great advantages of dual targeting properties. Furthermore, fluorescence microscope and flow cytometry results showed that PTX and DNA could be effectively co-delivered into the same tumor cell via HA/FA/PPD, contributing to PTX/DNA combination cancer treatment. In conclusion, the obtained HA/FA/PPD in the study could effectively target tumor cells, enhance transfection efficiency and subsequently achieve the co-delivery of PTX and DNA, displaying great potential for optimal combination therapy. PMID:25177862

Liu, Guo-Xia; Fang, Gui-Qing; Xu, Wei



Paclitaxel-Loaded, Folic-Acid-Targeted and TAT-Peptide-Conjugated Polymeric Liposomes: In Vitro and In Vivo Evaluation  

Microsoft Academic Search

Objective  Folic acid and TAT peptide were conjugated on the octadecyl-quaternized, lysine-modified chitosan-cholesterol polymeric liposomes\\u000a (FA-TATp-PLs) to investigate their potential feasibility for tumor-targeted drug delivery.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  FA-TATp-PLs encapsulating paclitaxel or calcein were synthesized and characterized. Cellular uptake of PLs, FA-PLs, TATp-PLs\\u000a and FA-TATp-PLs was studied by confocal laser scanning microscopy (CLSM) in folate receptor (FR)-positive KB nasopharyngeal\\u000a epidermal carcinoma cells and FR-deficient

Peiqi Zhao; Hanjie Wang; Man Yu; Shuzhen Cao; Fei Zhang; Jin Chang; Ruifang Niu



Aptamers for Targeted Drug Delivery  

PubMed Central

Aptamers are a class of therapeutic oligonucleotides that form specific three-dimensional structures that are dictated by their sequences. They are typically generated by an iterative screening process of complex nucleic acid libraries employing a process termed Systemic Evolution of Ligands by Exponential Enrichment (SELEX). SELEX has traditionally been performed using purified proteins, and cell surface receptors may be challenging to purify in their properly folded and modified conformations. Therefore, relatively few aptamers have been generated that bind cell surface receptors. However, improvements in recombinant fusion protein technology have increased the availability of receptor extracellular domains as purified protein targets, and the development of cell-based selection techniques has allowed selection against surface proteins in their native configuration on the cell surface. With cell-based selection, a specific protein target is not always chosen, but selection is performed against a target cell type with the goal of letting the aptamer choose the target. Several studies have demonstrated that aptamers that bind cell surface receptors may have functions other than just blocking receptor-ligand interactions. All cell surface proteins cycle intracellularly to some extent, and many surface receptors are actively internalized in response to ligand binding. Therefore, aptamers that bind cell surface receptors have been exploited for the delivery of a variety of cargoes into cells. This review focuses on recent progress and current challenges in the field of aptamer-mediated delivery.

Ray, Partha; White, Rebekah R.



The seco-taxane IDN5390 is able to target class III beta-tubulin and to overcome paclitaxel resistance.  


A prominent mechanism of drug resistance to taxanes is the overexpression of class III beta-tubulin. The seco-taxane IDN5390 was chosen for its selective activity in paclitaxel-resistant cells with an overexpression of class III beta-tubulin. Moreover, the combined treatment paclitaxel/IDN5390 yielded a strong synergism, which was also evident in cell-free tubulin polymerization assays. In the presence of an anti-class III beta-tubulin as a blocking antibody, tubulin polymerization induced by paclitaxel and IDN5390 was enhanced and not affected, respectively, whereas synergism was abolished, thereby indicating that IDN5390 activity is not modulated by class III beta-tubulin levels. Such properties can be explained by taking into consideration the composition of class III beta-tubulin paclitaxel binding site; in fact, Ser277 interacting with paclitaxel C group in class I is replaced by an Arginine in class III. IDN5390 that has an open and flexible C ring and an acidic alpha-unsaturated enol-keton moiety better fits with class III beta-tubulin than paclitaxel at the binding site. Taking altogether, these findings indicate that the concomitant treatment IDN5390/paclitaxel is able to successfully target class I and III beta-tubulin and the combined use of two taxanes with diverse spectrum activity against tubulin isotypes could represent a novel approach to overcome paclitaxel resistance. PMID:15781655

Ferlini, Cristiano; Raspaglio, Giuseppina; Mozzetti, Simona; Cicchillitti, Lucia; Filippetti, Flavia; Gallo, Daniela; Fattorusso, Caterina; Campiani, Giuseppe; Scambia, Giovanni



Targeted Nanogels: A Versatile Platform for Drug Delivery to Tumors  

PubMed Central

While nanoparticle-based drug delivery formulations can improve the effectiveness and safety of certain anti-cancer drugs, many drugs, due to their chemical composition, are unsuitable for nanoparticle loading. Here, we describe a targeted nanogel drug delivery platform that can 1) encapsulate a wide range of drug chemotypes including: biological, small molecule, and cytotoxic agents 2) display targeting ligands and polymeric coatings on the surface, 3) enhance drug retention within the nanogel core after photo-crosslinking, and 4) retain therapeutic activity after lyophilization allowing for long term storage. For therapeutic studies, we utilized integrin ?v?3-targeted lipid-coated nanogels with crosslinked human serum albumin in the core for carrying therapeutic cargoes. These particles exhibited potent activity in tumor cell viability assays with drugs of distinct chemotype including: paclitaxel, docetaxel, bortezomib, 17-AAG, sorafenib, sunitinib, bosutinib, and dasatinib. Treatment of orthotopic breast and pancreas tumors in mice with taxane-loaded nanogels produced a 15-fold improvement in anti-tumor activity relative to Abraxane by blocking both primary tumor growth and spontaneous metastasis. With a modifiable surface and core, the lipid-coated nanogel represents a platform technology that can be easily adapted for specific drug delivery applications to treat a wide range of malignant diseases. PMID:21518727

Murphy, Eric A.; Majeti, Bharat K.; Mukthavaram, Rajesh; Acevedo, Lisette M.; Barnes, Leo A.; Cheresh, David A.



Effective Drug Delivery, in vitro and in vivo, By Carbon-Based Nanovectors Non-Covalently Loaded With Unmodified Paclitaxel  

PubMed Central

Many new drugs have low aqueous solubility and high therapeutic efficacy. Paclitaxel (PTX) is a classic example of this type of compound. Here we show that extremely small (<40 nm) hydrophilic carbon clusters (HCCs) that are PEGylated (PEG-HCCs) are effective drug delivery vehicles when simply mixed with paclitaxel. This formulation of PTX sequestered in PEG-HCCs (PTX/PEG-HCCs) is stable for at least twenty weeks. The PTX/PEG-HCCs formulation was as effective as PTX in a clinical formulation in reducing tumor volumes in an orthotopic murine model of oral squamous cell carcinoma. Preliminary toxicity and biodistribution studies suggest that the PEG-HCCs are not acutely toxic and, like many other nanomaterials, are primarily accumulated in the liver and spleen. This work demonstrates that carbon nanomaterials are effective drug delivery vehicles in vivo when non-covalently loaded with an unmodified drug. PMID:20681596

Berlin, Jacob M.; Leonard, Ashley D.; Pham, Tam T.; Sano, Daisuke; Marcano, Daniela C.; Yan, Shayou; Fiorentino, Stefania; Milas, Zvonimir L.; Kosynkin, Dmitry V.; Katherine Price, B.; Lucente-Schultz, Rebecca M.; Wen, XiaoXia; Gabriela Raso, M.; Craig, Suzanne L.; Tran, Hai T.; Myers, Jeffrey N.; Tour, James M.



Radiosensitization of malignant gliomas following intracranial delivery of paclitaxel biodegradable polymer microspheres  

PubMed Central

Object The aim of this study was to demonstrate that paclitaxel could function as a radiosensitizer for malignant glioma in vitro and in vivo. Methods The radiosensitizing effect of paclitaxel was tested in vitro using the human U373MG and rat 9L glioma cell lines. Cell cycle arrest in response to paclitaxel exposure was quantified by flow cytometry. Cells were subsequently irradiated, and toxicity was measured using the clonogenic assay. In vivo studies were performed in Fischer 344 rats implanted with intracranial 9L gliosarcoma. Rats were treated with control polymer implants, paclitaxel controlled-release polymers, radiotherapy, or a combination of the 2 treatments. The study end point was survival. Results Flow cytometry demonstrated G2-M arrest in both U373MG and 9L cells following 6–12 hours of paclitaxel exposure. The order in which the combination treatment was administered was significant. Exposure to radiation treatment (XRT) during the 6–12 hours after paclitaxel treatment resulted in a synergistic reduction in colony formation. This effect was greater than the effect from either treatment alone and was also greater than the effect of radiation exposure followed by paclitaxel. Rats bearing 9L gliosarcoma tumors treated with paclitaxel polymer administration followed by single-fraction radiotherapy demonstrated a synergistic improvement in survival compared with any other treatment, including radiotherapy followed by paclitaxel treatment. Median survival for control animals was 13 days; for those treated with paclitaxel alone, 21 days; for those treated with XRT alone, 21 days; for those treated with XRT followed by paclitaxel, 45 days; and for those treated with paclitaxel followed by XRT, more than 150 days (p < 0.0001). Conclusions These results indicate that paclitaxel is an effective radiosensitizer for malignant gliomas because it renders glioma cells more sensitive to ionizing radiation by causing G2-M arrest, and induces a synergistic response to chemoradiotherapy. PMID:24605841

Gabikian, Patrik; Tyler, Betty M.; Zhang, Irma; Li, Khan W.; Brem, Henry; Walter, Kevin A.



Chitosan-alginate composites blended with cloisite 30B as a novel drug delivery system for anticancer drug paclitaxel  

Microsoft Academic Search

In the present research program, polymer composites have been used as the drug carrier for delivery system of anticancer drug\\u000a Paclitaxel. Chitosan (CS) and sodium alginate (ALG) with different ratios were blended with different wt% of montmorillonite\\u000a (MMT) (Cloisite 30B) solution by solvent evaporation method. MMT was incorporated in the formulation as a matrix material\\u000a component which also plays the

P. L. Nayak; Debasish Sahoo


A novel trans-lymphatic drug delivery system: Implantable gelatin sponge impregnated with PLGA–paclitaxel microspheres  

Microsoft Academic Search

A translymphatic drug delivery system which incorporates poly-lactide-co-glycolide–paclitaxel (PLGA–PTX) or PLGA–rhodamine microspheres into gelatin sponge matrix is described. The system combines the sustained release properties of PLGA–PTX with the structural advantages of gelatin matrix that can be implanted directly to the lymphatic site for both therapeutic and prophylactic purposes. The PLGA microspheres were prepared using spray drying technique. The particles

Jiang Liu; Dale Meisner; Elizabeth Kwong; Xiao Y. Wu; Michael R. Johnston




PubMed Central

Overexpression of drug efflux transporters such as P-glycoprotein (P-gp) enables cancer cells to develop resistance to multiple anticancer drugs. Functional inhibitors of P-gp have shown promising efficacy in early clinical trials, but their long-term safety is yet to be established. A novel approach to overcome drug resistance is to use siRNA-mediated RNA interference to silence the expression of the efflux transporter. Because P-gp plays an important role in the physiological regulation of endogenous and xenobiotic compounds in the body, it is important to deliver P-gp targeted siRNA and anticancer drug specifically to tumor cells. Further, for optimal synergy, both the drug and siRNA may need to be temporally colocalized in the tumor cells. In the current study, we investigated the effectiveness of simultaneous and targeted delivery of anticancer drug, paclitaxel, along with P-gp targeted siRNA, using poly(D,L-lactide-co-glycolide) nanoparticles to overcome tumor drug resistance. Nanoparticles were surface functionalized with biotin for active tumor targeting. Dual agent nanoparticles encapsulating the combination of paclitaxel and P-gp targeted siRNA showed significantly higher cytotoxicity in vitro than nanoparticles loaded with paclitaxel alone. Enhanced therapeutic efficacy of dual agent nanoparticles could be correlated with effective silencing of the MDR1 gene that encodes for P-gp and with increased accumulation of paclitaxel in drug-resistant tumor cells. In vivo studies in a mouse model of drug-resistant tumor demonstrated significantly greater inhibition of tumor growth following treatment with biotin-functionalized nanoparticles encapsulating both paclitaxel and P-gp targeted siRNA at a paclitaxel dose that was ineffective in the absence of gene silencing. These results suggest that that the combination of P-gp gene silencing and cytotoxic drug delivery using targeted nanoparticles can overcome tumor drug resistance. PMID:19800114

Patil, Yogesh; Swaminathan, Suresh; Sadhukha, Tanmoy; Ma, Linan; Panyam, Jayanth



Formulation and pharmacokinetic evaluation of a paclitaxel nanosuspension for intravenous delivery.  


Paclitaxel is a diterpenoid isolated from Taxus brevifolia. It is effective for various cancers, especially ovarian and breast cancer. Due to its aqueous insolubility, it is administered dissolved in ethanol and Cremophor EL (BASF, Ludwigshafen, Germany), which can cause serious allergic reactions. In order to eliminate Cremophor EL, paclitaxel was formulated as a nanosuspension by high-pressure homogenization. The nanosuspension was lyophilized to obtain the dry paclitaxel nanoparticles (average size, 214.4 ± 15.03 nm), which enhanced both the physical and chemical stability of paclitaxel nanoparticles. Paclitaxel dissolution was also enhanced by the nanosuspension. Differential scanning calorimetry showed that the crystallinity of paclitaxel was preserved during the high-pressure homogenization process. The pharmacokinetics and tissue distribution of paclitaxel were compared after intravenous administration of paclitaxel nanosuspension and paclitaxel injection. In rat plasma, paclitaxel nanosuspension exhibited a significantly (P < 0.01) reduced area under the concentration curve (AUC)(0-?) (20.343 ± 9.119 ?g · h · mL(-1) vs 5.196 ± 1.426 ?g · h · mL(-1)), greater clearance (2.050 ± 0.616 L · kg(-1) · h(-1) vs 0.556 ± 0.190 L · kg(-1) · h(-1)), and shorter elimination half-life (5.646 ± 2.941 vs 3.774 ± 1.352 hours) compared with the paclitaxel solution. In contrast, the paclitaxel nanosuspension resulted in a significantly greater AUC(0-?) in liver, lung, and spleen (all P < 0.01), but not in heart or kidney. PMID:21796250

Wang, Yonglu; Li, Xueming; Wang, Liyao; Xu, Yuanlong; Cheng, Xiaodan; Wei, Ping



Formulation and pharmacokinetic evaluation of a paclitaxel nanosuspension for intravenous delivery  

PubMed Central

Paclitaxel is a diterpenoid isolated from Taxus brevifolia. It is effective for various cancers, especially ovarian and breast cancer. Due to its aqueous insolubility, it is administered dissolved in ethanol and Cremophor® EL (BASF, Ludwigshafen, Germany), which can cause serious allergic reactions. In order to eliminate Cremophor EL, paclitaxel was formulated as a nanosuspension by high-pressure homogenization. The nanosuspension was lyophilized to obtain the dry paclitaxel nanoparticles (average size, 214.4 ± 15.03 nm), which enhanced both the physical and chemical stability of paclitaxel nanoparticles. Paclitaxel dissolution was also enhanced by the nanosuspension. Differential scanning calorimetry showed that the crystallinity of paclitaxel was preserved during the high-pressure homogenization process. The pharmacokinetics and tissue distribution of paclitaxel were compared after intravenous administration of paclitaxel nanosuspension and paclitaxel injection. In rat plasma, paclitaxel nanosuspension exhibited a significantly (P < 0.01) reduced area under the concentration curve (AUC)0–? (20.343 ± 9.119 ?g · h · mL?1 vs 5.196 ± 1.426 ?g · h · mL?1), greater clearance (2.050 ± 0.616 L · kg?1 · h?1 vs 0.556 ± 0.190 L · kg?1 · h?1), and shorter elimination half-life (5.646 ± 2.941 vs 3.774 ± 1.352 hours) compared with the paclitaxel solution. In contrast, the paclitaxel nanosuspension resulted in a significantly greater AUC0–? in liver, lung, and spleen (all P < 0.01), but not in heart or kidney. PMID:21796250

Wang, Yonglu; Li, Xueming; Wang, Liyao; Xu, Yuanlong; Cheng, Xiaodan; Wei, Ping



Preparation and evaluation of paclitaxel-loaded PEGylated immunoliposome  

Microsoft Academic Search

A sterically stabilized paclitaxel-loaded liposome tailored to target human breast cancer cells was developed, thereby promoting the efficiency of intracellular delivery of paclitaxel through receptor-mediated endocytosis. Results indicated that the targeting moiety (thiolated Herceptin) was successfully coupled to the distal reactive maleimide terminus of the poly (ethylene glycol)-phospholipid conjugate as well as being incorporated in the liposomal bilayers. The particle

Tao Yang; Min-Koo Choi; Fu-De Cui; Jung Sun Kim; Suk-Jae Chung; Chang-Koo Shim; Dae-Duk Kim



Ultrasound-Mediated Destruction of LHRHa Targeted and Paclitaxel Loaded Lipid Microbubbles for the Treatment of Intraperitoneal Ovarian Cancer Xenografts  

PubMed Central

Ultrasound-targeted microbubble destruction (UTMD) is a promising technique to facilitate the delivery of chemotherapy in cancer treatment. However, the process typically uses non-specific microbubbles, leading to low tumor-to-normal tissue uptake ratio and adverse side effects. In this study, we synthesized the LHRH receptor targeted and paclitaxel (PTX) loaded lipid microbubbles (TPLMBs) for tumor-specific binding and enhanced therapeutic effect at the tumor site. An ovarian cancer xenograft model was established by injecting A2780/DDP cells intraperitoneally in BALB/c nude mice. Microscopic imaging of tumor sections after intraperitoneal injection of TPLMBs showed effective binding of the microbubbles with cancer cells. Ultrasound mediated destruction of the intraperitoneally injected TPLMBs yielded a superior therapeutic outcome in comparison with other treatment options. Immunohistochemical analyses of the dissected tumor tissue further confirmed the increased tumor apoptosis and reduced angiogenesis. Our experiment suggests that ultrasound mediated intraperitoneal administration of the targeted drug-loaded microbubbles may be a useful method for the treatment of ovarian cancer. PMID:24237050

Chang, Shufang; Liu, Hongxia; Zhu, Yi; Wang, Zhigang; Xu, Ronald X.



The ClC-3 chloride channel associated with microtubules is a target of paclitaxel in its induced-apoptosis  

PubMed Central

Recent evidences show that cationic fluxes play a pivotal role in cell apoptosis. In this study, the roles of Cl? channels in paclitaxel-induced apoptosis were investigated in nasopharyngeal carcinoma CNE-2Z cells. Chloride current and apoptosis were induced by paclitaxel and inhibited by chloride channel blockers. Paclitaxel-activated current possessed similar properties to volume-activated chloride current. After ClC-3 was knocked-down by ClC-3-siRNA, hypotonicity-activated and paclitaxel-induced chloride currents were obviously decreased, indicating that the chloride channel involved in paclitaxel-induced apoptosis may be ClC-3. In early apoptotic cells, ClC-3 was up-regulated significantly; over-expressed ClC-3 was accumulated in cell membrane to form intercrossed filaments, which were co-localized with ?-tubulins; changes of ultrastructures and decrease of flexibility in cell membrane were detected by atomic force microscopy. These suggest that ClC-3 is a critical target of paclitaxel and the involvement of ClC-3 in apoptosis may be associated with its accumulation with membrane microtubules and its over activation. PMID:24026363

Zhang, Haifeng; Li, Huarong; Yang, Lili; Deng, Zhiqin; Luo, Hai; Ye, Dong; Bai, Zhiquan; Zhu, Linyan; Ye, Wencai; Wang, Liwei; Chen, Lixin



Poly-cyclodextrin and poly-paclitaxel nano-assembly for anticancer therapy  

NASA Astrophysics Data System (ADS)

Effective anticancer therapy can be achieved by designing a targeted drug-delivery system with high stability during circulation and efficient uptake by the target tumour cancer cells. We report here a novel nano-assembled drug-delivery system, formed by multivalent host-guest interactions between a polymer-cyclodextrin conjugate and a polymer-paclitaxel conjugate. The multivalent inclusion complexes confer high stability to the nano-assembly, which efficiently delivers paclitaxel into the targeted cancer cells via both passive and active targeting mechanisms. The ester linkages between paclitaxel and the polymer backbone permit efficient release of paclitaxel within the cell by degradation. This novel targeted nano-assembly exhibits significant antitumour activity in a mouse tumour model. The strategy established in this study also provides knowledge for the development of advanced anticancer drug delivery.

Namgung, Ran; Mi Lee, Yeong; Kim, Jihoon; Jang, Yuna; Lee, Byung-Heon; Kim, In-San; Sokkar, Pandian; Rhee, Young Min; Hoffman, Allan S.; Kim, Won Jong



Improving Paclitaxel Delivery: In Vitro and In Vivo Characterization of PEGylated Polyphosphoester-Based Nanocarriers.  


Nanomaterials have great potential to offer effective treatment against devastating diseases by providing sustained release of high concentrations of therapeutic agents locally, especially when the route of administration allows for direct access to the diseased tissues. Biodegradable polyphosphoester-based polymeric micelles and shell cross-linked knedel-like nanoparticles (SCKs) have been designed from amphiphilic block-graft terpolymers, PEBP-b-PBYP-g-PEG, which effectively incorporate high concentrations of paclitaxel (PTX). Well-dispersed nanoparticles physically loaded with PTX were prepared, exhibiting desirable physiochemical characteristics. Encapsulation of 10 wt% PTX, into either micelles or SCKs, allowed for aqueous suspension of PTX at concentrations up to 4.8 mg/mL, as compared to <2.0 ?g/mL for the aqueous solubility of the drug alone. Drug release studies indicated that PTX released from these nanostructures was defined through a structure-function relationship, whereby the half-life of sustained PTX release was doubled through cross-linking of the micellar structure to form SCKs. In vitro, physically loaded micellar and SCK nanotherapeutics demonstrated IC50 values against osteosarcoma cell lines, known to metastasize to the lungs (CCH-OS-O and SJSA), similar to the pharmaceutical Taxol formulation. Evaluation of these materials in vivo has provided an understanding of the effects of nanoparticle structure-function relationships on intratracheal delivery and related biodistribution and pharmacokinetics. Overall, we have demonstrated the potential of these novel nanotherapeutics toward future sustained release treatments via administration directly to the sites of lung metastases of osteosarcoma. PMID:25629952

Zhang, Fuwu; Zhang, Shiyi; Pollack, Stephanie F; Li, Richen; Gonzalez, Amelia M; Fan, Jingwei; Zou, Jiong; Leininger, Sarah E; Pavía-Sanders, Adriana; Johnson, Rachel; Nelson, Laura D; Raymond, Jeffery E; Elsabahy, Mahmoud; Hughes, Dennis M P; Lenox, Mark W; Gustafson, Tiffany P; Wooley, Karen L



Targeted Drug Delivery in Pancreatic Cancer  

PubMed Central

Effective drug delivery in pancreatic cancer treatment remains a major challenge. Because of the high resistance to chemo and radiation therapy, the overall survival rate for pancreatic cancer is extremely low. Recent advances in drug delivery systems hold great promise for improving cancer therapy. Using liposomes, nanoparticles, and carbon nanotubes to deliver cancer drugs and other therapeutic agents such as siRNA, suicide gene, oncolytic virus, small molecule inhibitor and antibody has been a success in recent pre-clinical trials. However, how to improve the specificity and stability of the delivered drug using ligand or antibody directed delivery represent a major problem. Therefore, developing novel, specific, tumor-targeted drug delivery systems is urgently needed for this terrible disease. This review summarizes the current progress on targeted drug delivery in pancreatic cancer, and provides important information on potential therapeutic targets for pancreatic cancer treatment. PMID:19853645

Yu, Xianjun; Zhang, Yuqing; Chen, Changyi; Yao, Qizhi; Li, Min



“OA02” Peptide Facilitates the Precise Targeting of Paclitaxel-Loaded Micellar Nanoparticles to Ovarian Cancer In Vivo  

PubMed Central

Micellar nanoparticles (NPs) based on linear polyethylene glycol (PEG)-block-dendritic cholic acids (CA) copolymers (telodendrimers), for the targeted delivery of chemotherapeutic drugs in the treatment of cancers, are reported. The micellar NPs have been decorated with a high-affinity “OA02” peptide against alpha-3 integrin receptor to improve the tumor targeting specificity which is overexpressed on the surface of ovarian cancer cells. “Click chemistry” was used to conjugate alkyne-containing OA02 peptide to the azide group at the distal terminus of the PEG chain in a representative PEG5k-CA8 telodendrimer (micelle forming unit). The conjugation of OA02 peptide had negligible influence on the physicochemical properties of PEG5k-CA8 NPs and as hypothesized, OA02 peptide dramatically enhanced the uptake efficiency of PEG5k-CA8 NPs in SKOV-3 and ES-2 ovarian cancer cells via receptor-mediated endocytosis, but not in alpha-3 integrin negative K562 leukemia cells. When loaded with paclitaxel (PTX), OA02-NPs had significantly higher in vitro cytotoxicity against both SKOV-3 and ES-2 ovarian cancer cells as compared with non-targeted NPs. Furthermore, the in vivo biodistribution study demonstrated OA02 peptide greatly facilitated tumor localization and the intracellular uptake of PEG5k-CA8 NPs into ovarian cancer cells as validated in SKOV3-luc tumor bearing mice. Finally, PTX-loaded OA02-NPs exhibited superior anti-tumor efficacy and lower systemic toxicity profile in nude mice bearing SKOV-3 tumor xenografts, when compared with equivalent doses of non-targeted PTX-NPs as well as clinical PTX formulation (Taxol®). Therefore, OA02 targeted telodendrimers loaded with PTX have great potential as a new therapeutic approach for ovarian cancer patients. PMID:22396491

Xiao, Kai; Li, Yuanpei; Lee, Joyce S.; Gonik, Abby M.; Dong, Tiffany; Fung, Gabriel; Sanchez, Eduardo; Xing, Li; Cheng, Holland R.; Luo, Juntao; Lam, Kit S.



Fate of paclitaxel lipid nanocapsules in intestinal mucus in view of their oral delivery  

PubMed Central

The bioavailability of paclitaxel (Ptx) has previously been improved via its encapsulation in lipid nanocapsules (LNCs). In this work, the interactions between LNCs and intestinal mucus are studied because they are viewed as an important barrier to successful oral delivery. The rheological properties of different batches of pig intestinal mucus were studied under different conditions (the effect of hydration and the presence of LNCs). Fluorescence resonance energy transfer (FRET) was used to study the stability of LNCs in mucus at 37°C for at least 3 hours. Diffusion through 223, 446, and 893 ?m mucus layers of 8.4, 16.8, and 42 ?g/mL Ptx formulated as Taxol® (Bristol-Myers Squibb, Rueil-Malmaison, France) or encapsulated in LNCs (Ptx-LNCs) were investigated. The effect of the size of the LNCs on their diffusion was also investigated (range, 25–110 nm in diameter). Mucus behaves as a non-Newtonian gel with rheofluidifying properties and a flow threshold. The viscous (G?) and elastic (G?) moduli and flow threshold of the two mucus batches varied with water content, but G? remained below G?. LNCs had no effect on mucus viscosity and flow threshold. The FRET efficiency remained at 78% after 3 hours. Because the destruction of the LNCs would lead to a FRET efficiency below 25%, these results suggest only a slight modification of LNCs after their contact with mucus. The diffusion of Taxol® and Ptx-LNCs in mucus decreases if the mucus layer is thicker. Interestingly, the apparent permeability across mucus is higher for Ptx-LNCs than for Taxol® for drug concentrations of 16.8 and 42 ?g/mL Ptx (P<0.05). The diffusion of Ptx-LNCs through mucus is not size-dependent. This study shows that LNCs are stable in mucus, do not change mucus rheological properties, and improve Ptx diffusion at low concentrations, thus making these systems good candidates for Ptx oral delivery. The study of the physicochemical interaction between the LNC surface and its diffusion in mucus is now envisioned. PMID:24235827

Groo, Anne-Claire; Saulnier, Patrick; Gimel, Jean-Christophe; Gravier, Julien; Ailhas, Caroline; Benoit, Jean-Pierre; Lagarce, Frederic



Fate of paclitaxel lipid nanocapsules in intestinal mucus in view of their oral delivery.  


The bioavailability of paclitaxel (Ptx) has previously been improved via its encapsulation in lipid nanocapsules (LNCs). In this work, the interactions between LNCs and intestinal mucus are studied because they are viewed as an important barrier to successful oral delivery. The rheological properties of different batches of pig intestinal mucus were studied under different conditions (the effect of hydration and the presence of LNCs). Fluorescence resonance energy transfer (FRET) was used to study the stability of LNCs in mucus at 37°C for at least 3 hours. Diffusion through 223, 446, and 893 ?m mucus layers of 8.4, 16.8, and 42 ?g/mL Ptx formulated as Taxol® (Bristol-Myers Squibb, Rueil-Malmaison, France) or encapsulated in LNCs (Ptx-LNCs) were investigated. The effect of the size of the LNCs on their diffusion was also investigated (range, 25-110 nm in diameter). Mucus behaves as a non-Newtonian gel with rheofluidifying properties and a flow threshold. The viscous (G?) and elastic (G') moduli and flow threshold of the two mucus batches varied with water content, but G' remained below G?. LNCs had no effect on mucus viscosity and flow threshold. The FRET efficiency remained at 78% after 3 hours. Because the destruction of the LNCs would lead to a FRET efficiency below 25%, these results suggest only a slight modification of LNCs after their contact with mucus. The diffusion of Taxol® and Ptx-LNCs in mucus decreases if the mucus layer is thicker. Interestingly, the apparent permeability across mucus is higher for Ptx-LNCs than for Taxol® for drug concentrations of 16.8 and 42 ?g/mL Ptx (P<0.05). The diffusion of Ptx-LNCs through mucus is not size-dependent. This study shows that LNCs are stable in mucus, do not change mucus rheological properties, and improve Ptx diffusion at low concentrations, thus making these systems good candidates for Ptx oral delivery. The study of the physicochemical interaction between the LNC surface and its diffusion in mucus is now envisioned. PMID:24235827

Groo, Anne-Claire; Saulnier, Patrick; Gimel, Jean-Christophe; Gravier, Julien; Ailhas, Caroline; Benoit, Jean-Pierre; Lagarce, Frederic



Folate and CD44 receptors dual-targeting hydrophobized hyaluronic acid paclitaxel-loaded polymeric micelles for overcoming multidrug resistance and improving tumor distribution.  


The drug efflux mediated by P-glycoprotein (P-gp) transporter is one of the important factors responsible for multidrug resistance (MDR), and then the efficient intracellular drug delivery is an important strategy to overcome MDR of tumor cells. We describe and compare CD44 receptor single-targeting and folate (FA), CD44 receptors dual-targeting hyaluronic acid-octadecyl (HA-C18 ) micellar formulations to overcome MDR of tumor cells and to improve tumor distribution. In comparison with Taxol solution, the cytotoxicity of paclitaxel (PTX) loaded in HA-C18 and FA-HA-C18 micelles against drug-resistant tumor cells was improved significantly because of the increased intracellular delivery by active receptor-mediated endocytosis. Compared with the single-targeting micelles, dual-targeting micelles possessed better MDR-overcoming performance. Pharmacokinetic study demonstrated HA-C18 and FA-HA-C18 PTX-loaded micelles possessed much longer circulation and moderately larger AUC than Taxol solution. Above all, the tumor distribution in MCF-7 tumor-bearing mice of PTX encapsulated in HA-C18 and FA-HA-C18 micelles were 2.8 and 4.0 times higher than that of Taxol solution. It was concluded that dual-targeting FA-HA-C18 micelles demonstrate excellent MDR-overcoming ability and improved tumor distribution, and provide a novel effective nanoplatform for anticancer drug delivery in cancer chemotherapy. PMID:24619562

Liu, Yanhua; Sun, Jin; Lian, He; Cao, Wen; Wang, Yongjun; He, Zhonggui



Radiation-guided drug delivery to mouse models of lung cancer  

PubMed Central

Purpose The purpose of this study was to achieve improved cancer-specific delivery and bioavailability of radiation-sensitizing chemotherapy using radiation-guided drug delivery. Experimental Design Phage display technology was used to isolate a recombinant peptide (HVGGSSV) that binds to a radiation-inducible receptor in irradiated tumors. This peptide was used to target nab-paclitaxel to irradiated tumors, achieving tumor-specificity and enhanced bioavailability of paclitaxel. Results Optical imaging studies showed that HVGGSSV guided nab-paclitaxel selectively targeted irradiated tumors and showed 1.48 ± 1.66 photons/s/cm2/sr greater radiance compared to SGVSGHV-nab-paclitaxel, and 1.49 ± 1.36 photons/s/cm2/sr greater than nab-paclitaxel alone (p<0.05). Biodistribution studies showed more than 5-fold increase in paclitaxel levels within irradiated tumors in HVGGSSV-nab-paclitaxel treated groups as compared to either nab-paclitaxel or SGVSGHV-nab-paclitaxel at 72 hrs. Both LLC and H460 lung carcinoma murine models showed significant tumor growth delay for HVGGSSV-nab-paclitaxel as compared to nab-paclitaxel, SGVSGHV-nab-paclitaxel and saline controls. HVGGSSV-nab-paclitaxel treatment induced a significantly greater loss in vasculature in irradiated tumors compared to unirradiated tumors, nab-paclitaxel, SGVSGHV-nab-paclitaxel, and untreated controls. Conclusions HVGGSSV nab-paclitaxel was found to bind specifically to the TIP-1 receptor expressed in irradiated tumors, enhance bioavailability of paclitaxel, and significantly increase tumor growth delay as compared to controls in mouse models of lung cancer. Here we show that targeting nab-paclitaxel to radiation-inducible TIP-1 results in increased tumor-specific drug delivery and enhanced biological efficacy in the treatment of cancer. PMID:20802016

Hariri, Ghazal; Yan, Heping; Wang, Hailun; Han, Zhaozhong; Hallahan, Dennis E.



Folate-targeted paclitaxel-conjugated polymeric micelles inhibits pulmonary metastatic hepatoma in experimental murine H22 metastasis models  

PubMed Central

Hepatocellular carcinoma shows low response to most conventional chemotherapies; additionally, extrahepatic metastasis from hepatoma is considered refractory to conventional systemic chemotherapy. Target therapy is a promising strategy for advanced hepatoma; however, targeted accumulation and controlled release of therapeutic agents into the metastatic site is still a great challenge. Folic acid (FA) and paclitaxel (PTX) containing composite micelles (FA-M[PTX]) were prepared by coassembling the FA polymer conjugate and PTX polymer conjugate. The main purpose of this study is to investigate the inhibitory efficacy of FA-M(PTX) on the pulmonary metastasis of intravenously injected murine hepatoma 22 (H22) on BALB/c mice models. The lung metastatic burden of H22 were measured and tissues were analyzed by immunohistochemistry and histology (hematoxylin and eosin stain), followed by survival analysis. The results indicated that FA-M(PTX) prevented pulmonary metastasis of H22, and the efficacy was stronger than pure PTX and simple PTX-conjugated micelles. In particular, the formation of lung metastasis colonies in mice was evidently inhibited, which was paralleled with the downregulated expression of matrix metalloproteinase-2 and matrix metalloproteinase-9. Furthermore, the mice bearing pulmonary metastatic hepatoma in the FA-M(PTX) group gained significantly prolonged survival time when compared with others given equivalent doses of PTX of 30 mg/kg. The enhanced efficacy of FA-M(PTX) is theoretically ascribed to the target effect of FA; moreover, the extensive pulmonary capillary networks may play a role. In conclusion, FA-M(PTX) displayed great potential as a promising antimetastatic agent, and the FA-conjugated micelles is a preferential targeted delivery system when compared to micelles without FA. PMID:24790440

Zhang, Yan; Zhang, Hui; Wu, Wenbin; Zhang, Fuhong; Liu, Shi; Wang, Rui; Sun, Yingchun; Tong, Ti; Jing, Xiabin



pH and glutathion-responsive hydrogel for localized delivery of paclitaxel.  


pH and glutathion (GSH)- responsive nanogels (NGs) based on poly-N-isopropylacrilamide (NIPA), N-hydroxyethyl acrylamide (HEAA) and tert-butyl 2-acrylamidoethyl carbamate (2AAECM) were synthesized by a microemulsion polymerization method using N, N'-cystaminebisacrylamide (CBA) as a crosslinking agent and evaluated for passive targeting of paclitaxel (PTX). Physicochemical characterizations of unloaded and PTX-loaded NGs, such as particle size, morphology, encapsulation efficiency and in vitro PTX release were also assessed. Electron microscopy techniques (SEM and TEM) as well as dynamic light scattering (DLS) analysis showed nanosized spherical hydrogels. FTIR spectra confirmed the synthesis of nanogels by free radical polymerization among vinyl groups of monomers. In vitro release was analyzed by high-performance liquid chromatography (HPLC) and differences between two NG formulations were obtained. Nanogels released almost 64% of PTX after 50h at GSH concentrations equivalent to that in the cellular cytosol, whereas less PTX was released from NGs at pH and GSH levels similar to plasma. Cellular uptake and cytotoxicity were also demonstrated by using coumarin-6 and MTT assays, respectively, for three tumor cell lines (MCF7, HeLa and T47D). Cellular uptake assays revealed rapid uptake within 2h and intracellular accumulation of coumarin-6-loaded nanogels after 48 h incubation. MTT assays showed changes in cell viability at different concentrations of PTX formulations, as well as pure PTX (10 ?M, 20 ?M and 30 ?M). To investigate PTX effect on cell viability, changes in cell cycle were examined by flow cytometry and a G2/M cell arrest was demonstrated. Overall, synthesized nanogels may be used as potential carriers for hydrophobic anticancer drugs. PMID:24491841

Pérez, Elena; Fernández, Ana; Olmo, Rosa; Teijón, Jose M; Blanco, M Dolores



Self-assembled silk sericin\\/poloxamer nanoparticles as nanocarriers of hydrophobic and hydrophilic drugs for targeted delivery  

Microsoft Academic Search

In recent times self-assembled micellar nanoparticles have been successfully employed in tissue engineering for targeted drug delivery applications. In this review, silk sericin protein from non-mulberry Antheraea mylitta tropical tasar silk cocoons was blended with pluronic F-127 and F-87 in the presence of solvents to achieve self-assembled micellar nanostructures capable of carrying both hydrophilic (FITC-inulin) and hydrophobic (anticancer drug paclitaxel)

Biman B. Mandal; S. C. Kundu



IFE Target Fabrication, Delivery, and Cost Estimates  

E-print Network

IFE Target Fabrication, Delivery, and Cost Estimates N. B. Alexander, L. Brown, D. Callahan, P degrees... SOMBRERO 3-D model for neutronics analysisLaser Fusion HIF - HYLIFE-II ZFE #12;An initial cost analysis has been done for an "nth-of-a-kind" IFE target manufacturing Goodin, D.T., et al, "A cost


Tumor-Targeted Drug Delivery with Aptamers  

PubMed Central

Cancer is one of the leading causes of death around the world. Tumor-targeted drug delivery is one of the major areas in cancer research. Aptamers exhibit many desirable properties for tumor-targeted drug delivery, such as ease of selection and synthesis, high binding affinity and specificity, low immunogenicity, and versatile synthetic accessibility. Over the last several years, aptamers have quickly become a new class of targeting ligands for drug delivery applications. In this review, we will discuss in detail about aptamer-based delivery of chemotherapy drugs (e.g. doxorubicin, docetaxel, daunorubicin, and cisplatin), toxins (e.g. gelonin and various photodynamic therapy agents), and a variety of small interfering RNAs. Although the results are promising which warrants enthusiasm for aptamer-based drug delivery, tumor homing of aptamer-based conjugates after systemic injection has only been achieved in one report. Much remains to be done before aptamer-based drug delivery can reach clinical trials and eventually the day-to-day management of cancer patients. Therefore, future directions and challenges in aptamer-based drug delivery are also discussed. PMID:21838687

Zhang, Yin; Hong, Hao; Cai, Weibo



Folate-mediated targeting of albumin conjugates of paclitaxel obtained through a heterogeneous phase system.  


The study developed cytotoxic macromolecular conjugates that specifically target the folate receptor and deliver the drug into cell cytoplasm. The anticancer agent paclitaxel was conjugated to human serum albumin (HSA) and this drug-albumin conjugate was further equipped with folic acid, linked via an extended poly(ethylene glycol) spacer. Preparation was carried out in a heterogeneous phase system exploiting the binding ability of Cibacron Blue dye to HSA. Unreacted reagents were easily removed and, after purification by gel filtration, the conjugate was fully characterized. Binding and in vitro cytotoxicity studies on human nasopharyngeal epidermal carcinoma KB and colorectal carcinoma HT-29 cells (as negative control) demonstrated increased selectivity and anti-tumoral activity. PMID:19712735

Dosio, Franco; Arpicco, Silvia; Stella, Barbara; Brusa, Paola; Cattel, Luigi



A self-assembling nanoparticle for paclitaxel delivery in ovarian cancer  

Microsoft Academic Search

Paclitaxel (PTX) is one of the most effective chemotherapeutic drugs for the treatment of a variety of cancers. However, it is associated with serious side effects caused by PTX itself and the Cremophor EL emulsifier. In the present study, we report the development of a well-defined amphiphilic linear-dendritic copolymer (named as telodendrimer) composed of polyethylene glycol (PEG), cholic acid (CA,

Kai Xiao; Juntao Luo; Wiley L. Fowler; Yuanpei Li; Joyce S. Lee; Li Xing; R. Holland Cheng; Li Wang; Kit S. Lam



Bioadhesive Drug Delivery System Using Glyceryl Monooleate for the Intravesical Administration of Paclitaxel  

Microsoft Academic Search

Background: Many reports have shown that the efficacy of intravesical therapy for bladder cancer is in part limited by the poor penetration of drugs into the urothelium. The present study evaluated the effect of glyceryl monooleate (GMO) on the absorption of intravesically administered paclitaxel in a rabbit model of bladder cancer. Methods: Urine, plasma, and tissue pharmacokinetics were determined in

Seung-Ju Lee; Sae Woong Kim; Hesson Chung; Yeong Taek Park; Young Wook Choi; Yong-Hyun Cho; Moon Soo Yoon



Nanoparticles for intracellular-targeted drug delivery  

NASA Astrophysics Data System (ADS)

Nanoparticles (NPs) are very promising for the intracellular delivery of anticancer and immunomodulatory drugs, stem cell differentiation biomolecules and cell activity modulators. Although initial studies in the area of intracellular drug delivery have been performed in the delivery of DNA, there is an increasing interest in the use of other molecules to modulate cell activity. Herein, we review the latest advances in the intracellular-targeted delivery of short interference RNA, proteins and small molecules using NPs. In most cases, the drugs act at different cellular organelles and therefore the drug-containing NPs should be directed to precise locations within the cell. This will lead to the desired magnitude and duration of the drug effects. The spatial control in the intracellular delivery might open new avenues to modulate cell activity while avoiding side-effects.

Paulo, Cristiana S. O.; Pires das Neves, Ricardo; Ferreira, Lino S.



The Effect of Short-term Intra-arterial Delivery of Paclitaxel on Neointimal Hyperplasia and the Local Thrombotic Environment after Angioplasty  

SciTech Connect

PurposeTo evaluate the effects of short-term intra-arterial delivery of paclitaxel on neointimal hyperplasia and the local thrombotic environment after angioplasty.MethodsAn experimental common carotid artery injury model was established in 60 rats, which were divided into experimental groups (40 rats) and controls (20 rats). Local intra-arterial administration of paclitaxel was applied at 2 doses (90 and 180 {mu}g/30 {mu}l), and the effects of short-term delivery of paclitaxel on neointimal hyperplasia and the expression of tissue factor (TF), plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) were evaluated at days 15 and 30 by hematoxylin and eosin staining and immunohistochemistry.ResultsAt 15 and 30 days after injury, neointimal thickness and area, the ratio of intimal area to medial area and the stenotic rate were all significantly decreased in the group provided the high concentrations (180 {mu}g/30 {mu}l) of paclitaxel for 2 min or 10 min and in the group provided the low concentration (90 {mu}g/30 {mu}l) of paclitaxel for 10 min (p < 0.05). At 30 days after injury, there were no significant changes in TF expression among all experimental groups. PAI-1 expression increased in the neointima of the high concentration 10 min group (p < 0.05), while t-PA expression decreased in the neointima of the high concentration 2 min group (p < 0.05).ConclusionIn the rat common carotid artery injury model, the short-term delivery of paclitaxel could effectively inhibit neointimal hyperplasia in the long term, with very little influence on the local expression of TF and PAI-1.

Yajun, E, E-mail: [Affiliated Hospital of Hebei University, Department of Interventional Radiology (China); He Nengshu, E-mail:; Fan Hailun, E-mail: [Tianjin Institute of Radiology, General Hospital of Tianjin Medical University, Department of Radiology (China)



Co-delivery of doxorubicin and paclitaxel by PEG-polypeptide nanovehicle for the treatment of non-small cell lung cancer.  


Despite progress, combination therapy of different functional drugs to increase the efficiency of anticancer treatment still remains challenges. An amphiphilic methoxy poly(ethylene glycol)-b-poly(l-glutamic acid)-b-poly(l-lysine) triblock copolymer decorated with deoxycholate (mPEsG-b-PLG-b-PLL/DOCA) was synthesized and developed as a nanovehicle for the co-delivery of anticancer drugs: doxorubicin (DOX) and paclitaxel (PTX). The amphiphilic copolymer spontaneously self-assembled into micellar-type nanoparticles in aqueous solutions and the blank nanoparticles possessed excellent stability. Three different domains of the copolymer performed distinct functions: PEG outer corona provided prolonged circulation, middle biodegradable and hydrophilic PLG shell was designed for DOX loading through electrostatic interactions, and hydrophobic deoxycholate modified PLL served as the container for PTX. In vitro cytotoxicity assays against A549 human lung adenocarcinoma cell line demonstrated that the DOX + PTX co-delivered nanoparticles (Co-NPs) exhibited synergistic effect in inducing cancer cell apoptosis. Ex vivo DOX fluorescence imaging revealed that Co-NPs had highly efficient targeting and accumulation at the implanted site of A549 xenograft tumor in vivo. Co-NPs exhibited significantly higher antitumor efficiency in reducing tumor size compared to free drug combination or single drug-loaded nanoparticles, while no obvious side effects were observed during the treatment, indicating this co-delivery system with different functional antitumor drugs provides the clinical potential in cancer therapy. PMID:24794923

Lv, Shixian; Tang, Zhaohui; Li, Mingqiang; Lin, Jian; Song, Wantong; Liu, Huaiyu; Huang, Yubin; Zhang, Yuanyuan; Chen, Xuesi



Replacing Heme with Paclitaxel to Prepare Drug-Loaded Globin Nanoassembles for CD163 Targeting.  


Protein-based nanoparticles hold great promises in both preclinical and clinical practices, such as oncology diagnosis and treatment, because of their high biocompatibility and biodegradability. However, the complicated preparation and lack of targeting specific cells or tissues may limit their further uses. To overcome these limitations, we developed a novel replacing method for preparing dual-functional protein nanocarrier, such that one function is capable of encapsulating small molecule into protein, whereas the other function is cable of recognizing CD163 receptor [hemoglobin (Hb) scavenger receptor]. In this study, Hb was chosen as the targeting drug carrier. First, the heme group in the Hb was removed and replaced by paclitaxel (PTX) to form nanoparticles (Gb-NPs-PTX). The resulted Gb-NPs-PTX showed spherical shape and their diameter could be controlled in the range of 120-160 nm by altering the ratio of PTX to Hb. The binding activity of Gb-NPs-PTX to CD163 was confirmed by cell uptake in CD163(+) Chinese hamster ovary cells. Results in vivo also showed a CD163-dependent tissue accumulation of Gb-NPs-PTX in mice. In summary, by using the novel replacing method, PTX could be easily encapsulated into Hb nanoparticles and the targeting effects of Hb could also be kept. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:1045-1055, 2015. PMID:25640195

Meng, Zhengjie; Yang, Xiaoyan; Hu, Die; Wang, Kaikai; Zhi, Feng; Chen, Xi; Gong, Guangming; Wu, Jinhui; Hu, Yiqiao



Implications of nanoscale based drug delivery systems in delivery and targeting tubulin binding agent, noscapine in cancer cells.  


Noscapine, a tubulin binding anticancer agent undergoing Phase I/II clinical trials, inhibits tumor growth in nude mice bearing human xenografts of breast, lung, ovarian, brain, and prostrate origin. The analogues of noscapine like 9-bromonoscapine (EM011) are 5 to 10-fold more active than parent compound, noscapine. Noscapinoids inhibit the proliferation of cancer cells that are resistant to paclitaxel and epothilone. Noscapine also potentiated the anticancer activity of doxorubicin in a synergistic manner against triple negative breast cancer (TNBC). However, physicochemical and pharmacokinetic (ED50˜300-600 mg/kg bodyweight) limitations of noscapine present hurdle in development of commercial anticancer formulations. Therefore, objectives of the present review are to summarize the chemotherapeutic potential of noscapine and implications of nanoscale based drug delivery systems in enhancing the therapeutic efficacy of noscapine in cancer cells. We have constructed noscapine-enveloped gelatin nanoparticles, NPs and poly (ethylene glycol) grafted gelatin NPs as well as inclusion complex of noscapine in ?-cyclodextrin (?-CD) and evaluated their physicochemical characteristics. The Fe3O4 NPs were also used to incorporate noscapine in its polymeric nanomatrix system where molecular weight of the polymer governed the encapsulation efficiency of drug. The enhanced noscapine delivery using ?PAR-targeted optical-MR imaging trackable NPs offer a great potential for image directed targeted delivery of noscapine. Human Serum Albumin NPs (150-300 nm) as efficient noscapine drug delivery systems have also been developed for potential use in breast cancer. PMID:22571485

Chandra, Ramesh; Madan, Jitender; Singh, Prashant; Chandra, Ankush; Kumar, Pradeep; Tomar, Vartika; Dass, Sujata K



Magnetizable implants for targeted drug delivery  

NASA Astrophysics Data System (ADS)

The capability to deliver high effective dosages to specific sites in the human body has become the holy grail of drug delivery research. Drugs with proven effectiveness under in vitro investigation often reach a major roadblock under in vivo testing due to a lack of an effective delivery strategy. In addition, many clinical scenarios require delivery of agents that are therapeutic at the desired delivery point, but otherwise systemically toxic. This project proposes a method for targeted drug delivery by applying high magnetic field gradients within the body to an injected superparamagnetic colloidal fluid carrying a drug, with the aid of modest uniform magnetic field. The design involves patterning of endovascular implants, such as coronary stents, with soft magnetic coatings capable of applying high local magnetic field gradients within the body. Examination of the feasibility of the design has been focused around the treatment of coronary restenosis following angioplasty. Drug-eluting stents, which have debuted in hospitals over the past two years, have thus far reduced restenosis rates to below 10%. Our local drug delivery system is a viable alternative or enhancement to drug-eluting stents, offering increased clinician control of dose size, the ability to treat a site repeatedly, and a wide array of applications for treatment of other pathologies. The theoretical models, parallel plate and pipe flow analysis, and cell culture models presented give insight into the use of micron and sub-micron scale magnetic particles for site-specific delivery of pharmaceuticals and magnetically labeled cells.

Forbes, Zachary Graham


Targeted drug delivery via the folate receptor  

Microsoft Academic Search

The folate receptor is a highly selective tumor marker overexpressed in greater than 90% of ovarian carcinomas. Two general strategies have been developed for the targeted delivery of drugs to folate receptor-positive tumor cells: by coupling to a monoclonal antibody against the receptor and by coupling to a high affinity ligand, folic acid. First, antibodies against the folate receptor, including

Jennifer Sudimack; Robert J Lee



In vivo pharmacokinetics, biodistribution and anti-tumor effect of paclitaxel-loaded targeted chitosan-based polymeric micelle.  


Abstract A water-insoluble anti-tumor agent, paclitaxel (PTX) was successfully incorporated into novel-targeted polymeric micelles based on tocopherol succinate-chitosan-polyethylene glycol-folic acid (PTX/TS-CS-PEG-FA). The aim of the present study was to evaluate the pharmacokinetics, tissue distribution and efficacy of PTX/TS-CS-PEG-FA in comparison to Anzatax® in tumor bearing mice. The micellar formulation showed higher in vitro cytotoxicity against mice breast cancer cell line, 4T1, due to the folate receptor-mediated endocytosis. The IC50 value of PTX, a concentration at which 50% cells are killed, was 1.17 and 0.93?µM for Anzatax® and PTX/TS-CS-PEG-FA micelles, respectively. The in vivo anti-tumor efficacy of PTX/TS-CS-PEG-FA, as measured by reduction in tumor volume of 4T1 mouse breast cancer injected in Balb/c mice was significantly greater than that of Anzatax®. Pharmacokinetic study in tumor bearing mice revealed that the micellar formulation prolonged the systemic circulation time of PTX and the AUC of PTX/TS-CS-PEG-FA was obtained 0.83-fold lower than Anzatax®. Compared with Anzatax®, the Vd, T1/2ß and MRT of PTX/TS-CS-PEG-FA was increased by 2.76, 2.05 and 1.68-fold, respectively. As demonstrated by tissue distribution, the PTX/TS-CS-PEG-FA micelles increased accumulation of PTX in tumor, therefore, resulted in anti-tumor effects enhancement and drug concentration in the normal tissues reduction. Taken together, our evaluations show that PTX/TS-CS-PEG-FA micelle is a potential drug delivery system of PTX for the effective treatment of the tumor and systematic toxicity reduction, thus, the micellar formulation can provide a useful alternative dosage form for intravenous administration of PTX. PMID:25188785

Rezazadeh, Mahboubeh; Emami, Jaber; Hasanzadeh, Farshid; Sadeghi, Hojjat; Minaiyan, Mohsen; Mostafavi, Abolfazl; Rostami, Mahboubeh; Lavasanifar, Afsaneh



A self-assembling nanoparticle for paclitaxel delivery in ovarian cancer  

PubMed Central

Paclitaxel (PTX) is one of the most effective chemotherapeutic drugs for the treatment of a variety of cancers. However, it is associated with serious side effects caused by PTX itself and the Cremophor EL emulsifier. In the present study, we report the development of a well-defined amphiphilic linear–dendritic copolymer (named as telodendrimer) composed of polyethylene glycol (PEG), cholic acid (CA, a facial amphiphilic molecule) and lysine, which can form drug-loaded core/shell micelles when mixed with hydrophobic drug, such as PTX, under aqueous condition. We have used PEG5k-CA8, a representive telodendrimer, to prepare paclitaxel-loaded nanoparticles (PTX-PEG5k-CA8 NPs) with high loading capacity (7.3 mg PTX/mL) and a size of 20–60 nm. This novel nanoformulation of PTX was found to exhibit similar in vitro cytotoxic activity against ovarian cancer cells as the free drug (Taxol®) or paclitaxel/ human serum albumin nanoaggregate (Abraxane®). The maximum tolerated doses (MTDs) of PTX-PEG5k-CA8 NPs after single dose and five consective daily doses in mice were approximately 75 and 45 mg PTX/kg, respectively, which were 2.5-fold higher than those of Taxol®. In both subcutaneous and orthotopic intraperitoneal murine models of ovarian cancer, PTX-PEG5k-CA8 NPs achieved superior toxicity profiles and antitumor effects compared to Taxol® and Abraxane® at equivalent PTX doses, which were attributed to their preferential tumor accumulation, and deep penetration into tumor tissue, as confirmed by near infrared fluorescence (NIRF) imaging. PMID:19660809

Xiao, Kai; Luo, Juntao; Fowler, Wiley; Li, Yuanpei; Lee, Joyce; Wang, Li; Lam, Kit S.



Liposomes Loaded with Paclitaxel and Modified with Novel Triphenylphosphonium-PEG-PE Conjugate Possess Low Toxicity, Target Mitochondria and Demonstrate Enhanced Antitumor Effects In Vitro and In Vivo  

PubMed Central

Previously, stearyl triphenylphosphonium (STPP)-modified liposomes (STPP-L) were reported to target mitochondria. To overcome a non-specific cytotoxicity of STPP-L, we synthesized a novel polyethylene glycol- phosphatidylethanolamine (PEG-PE) conjugate with the TPP group attached to the distal end of the PEG block (TPP-PEG-PE). This conjugate was incorporated into the liposomal lipid bilayer, and the modified liposomes were studied for their toxicity, mitochondrial targeting, and efficacy in delivering paclitaxel (PTX) to cancer cells in vitro and in vivo. These TPP-PEG-PE-modified liposomes (TPP-PEG-L), surface grafted with as high as 8 mole % of the conjugate, were less cytotoxic compared to STPP-L or PEGylated STPP-L. At the same time, TPP-PEG-L demonstrated efficient mitochondrial targeting in cancer cells as shown by confocal microscopy in co-localization experiments with stained mitochondria. PTX-loaded TPP-PEG-L demonstrated enhanced PTX-induced cytotoxicity and anti-tumor efficacy in cell culture and mouse experiments compared to PTX-loaded unmodified plain liposomes (PL). Thus, TPP-PEG-PE can serve as a targeting ligand to prepare non-toxic liposomes as mitochondria-targeted drug delivery systems (DDS). PMID:22286008

Biswas, Swati; Dodwadkar, Namita S.; Deshpande, Pranali P.; Torchilin, Vladimir P.



Self-assembled silk sericin/poloxamer nanoparticles as nanocarriers of hydrophobic and hydrophilic drugs for targeted delivery  

NASA Astrophysics Data System (ADS)

In recent times self-assembled micellar nanoparticles have been successfully employed in tissue engineering for targeted drug delivery applications. In this review, silk sericin protein from non-mulberry Antheraea mylitta tropical tasar silk cocoons was blended with pluronic F-127 and F-87 in the presence of solvents to achieve self-assembled micellar nanostructures capable of carrying both hydrophilic (FITC-inulin) and hydrophobic (anticancer drug paclitaxel) drugs. The fabricated nanoparticles were subsequently characterized for their size distribution, drug loading capability, cellular uptake and cytotoxicity. Nanoparticle sizes ranged between 100 and 110 nm in diameter as confirmed by dynamic light scattering. Rapid uptake of these particles into cells was observed in in vitro cellular uptake studies using breast cancer MCF-7 cells. In vitro cytotoxicity assay using paclitaxel-loaded nanoparticles against breast cancer cells showed promising results comparable to free paclitaxel drugs. Drug-encapsulated nanoparticle-induced apoptosis in MCF-7 cells was confirmed by FACS and confocal microscopic studies using Annexin V staining. Up-regulation of pro-apoptotic protein Bax, down-regulation of anti-apoptotic protein Bcl-2 and cleavage of regulatory protein PARP through Western blot analysis suggested further drug-induced apoptosis in cells. This study projects silk sericin protein as an alternative natural biomaterial for fabrication of self-assembled nanoparticles in the presence of poloxamer for successful delivery of both hydrophobic and hydrophilic drugs to target sites.

Mandal, Biman B.; Kundu, S. C.



A Dicarboxylic Fatty Acid Derivative of Paclitaxel for Albumin Assisted Drug Delivery  

PubMed Central

Paclitaxel is a potent chemotherapy for many cancers but it suffers from very poor solubility. Consequently the TAXOL formulation uses copious amounts of the surfactant Cremophor EL to solubilize the drug for injection resulting in severe hypersensitivity and neutropenia. In contrast to Cremophor EL, presented is a way to solubilize paclitaxel (PTX) by conjugation of a dicarboxylic fatty acid for specific binding to the ubiquitous protein, serum albumin. The conjugation chemistry was simplified to a single step using the activated anhydride form of 3-pentadecylglutaric (PDG) acid which is reactive to a variety of nucleophiles. The PDG derivative is less cytotoxic than the parent compound and was found to slowly hydrolyze to PTX (~5% over 72 h) in serum, tumor cytosol, and tumor tissue homogenate. When injected intravenously to tumor bearing mice, [3H]-PTX in the TAXOL formulation was cleared rapidly with a half-life of 7 hours. In the case of the PDG derivative of PTX, the drug is quickly distributed and approximately 20% of the injected dose remained in the vasculature experiencing a 23-h half-life. These improvements from modifying PTX with the PDG fatty acid present the opportunity for PDG to become a generic modification for the improvement of many therapeutics. PMID:22674061

Hackett, Michael J.; Joolakanti, Shyamsunder; Hartranft, Megan E.; Guley, Patrick C.; Cho, Moo J.



Controlled delivery of paclitaxel from stent coatings using poly(hydroxystyrene-b-isobutylene-b-hydroxystyrene) and its acetylated derivative.  


A poly(styrene-b-isobutylene-b-styrene) (SIBS) triblock polymer is employed as the polymer drug carrier for the TAXUS Express2 Paclitaxel-Eluting Coronary Stent system (Boston Scientific Corp.). It has been shown that the release of paclitaxel (PTx) from SIBS can be modulated by modification of either drug-loading ratio or altering the triblock morphology by blending. In the present work, results toward achieving release modulation of PTx by chemical modification of the styrenic portion (using hydroxystyrene or its acetylated version) of the SIBS polymer system are reported. The synthesis of the precursor poly[(p-tert-butyldimethylsilyloxystyrene)]-b-isobutylene-b-[(p-tert-butyldimethylsilyloxystyrene] triblock copolymers was accomplished by living sequential block copolymerization of isobutylene (IB) and p-(tert-butyldimethylsiloxy)styrene (TBDMS) utilizing the capping-tuning technique in a one-pot procedure in methylcyclohexane/CH3Cl at -80 degrees C. This procedure involved the living cationic polymerization of IB with the 5-tert-butyl-1,3-bis(1-chloro-1-methylethyl)benzene/TiCl4 initiating system and capping of living difunctional polyisobutylene (PIB) chain ends with 1,1-ditolylethylene (DTE) followed by addition of titanium(IV) isopropoxide (Ti(OIp)4) to lower the Lewis acidity before the introduction of TBDMS. Deprotection of the product with tetrabutylammonium fluoride yielded poly(hydroxystyrene-b-isobutylene-b-hydroxystyrene), which was quantitatively acetylated to obtain the acetylated derivative. The hydroxystyrene and acetoxystyrene triblock copolymers have acceptable mechanical properties for use as drug delivery coatings for coronary stent applications. It was concluded that the hydrophilic nature of the endblocks and polarity effects on the drug/polymer miscibility lead to enhanced release of PTx from these polymers. The drug-polymer miscibility was confirmed by differential scanning calorimetry and atomic force microscopy evaluations. PMID:16153094

Sipos, Laszlo; Som, Abhijit; Faust, Rudolf; Richard, Robert; Schwarz, Marlene; Ranade, Shrirang; Boden, Mark; Chan, Ken



Amphiphilic carboxymethyl chitosan-quercetin conjugate with P-gp inhibitory properties for oral delivery of paclitaxel.  


An amphiphilic carboxymethyl chitosan-quercetin (CQ) conjugate was designed and synthesized for oral delivery of paclitaxel (PTX) to improve its oral bioavailability by increasing its water solubility and bypassing the P-gp drug efflux pumps. CQ conjugate had low critical micelle concentration (55.14 ?g/mL), and could self assemble in aqueous condition to form polymeric micelles (PMs). PTX-loaded CQ PMs displayed a particle size of 185.8 ± 4.6 nm and polydispersity index (PDI) of 0.134 ± 0.056. The drug-loading content (DL) and entrapment efficiency (EE) were 33.62 ± 1.34% and 85.63 ± 1.26%, respectively. Moreover, PTX-loaded CQ PMs displayed similar sustained-release profile in simulated gastrointestinal fluids (pH 1.2/pH 6.8) and PBS (pH 7.4). In situ intestinal absorption experiment showed that PTX-loaded CQ PMs significantly improved the effective permeability of PTX as compared to verapamil (P < 0.01). Likewise, PTX-loaded CQ PMs significantly enhanced the oral bioavailability of PTX, resulting in strong antitumor efficacy against tumor xenograft models with better safety profile as compared to Taxol(®) and Taxol(®) with verapamil. Overall, the results implicate that CQ PMs are promising vehicles for the oral delivery of water-insoluble anticancer drugs. PMID:24927684

Wang, Xiaoying; Chen, Yihang; Dahmani, Fatima Zohra; Yin, Lifang; Zhou, Jianping; Yao, Jing



Paclitaxel/Epigallocatechin gallate coloaded liposome: A synergistic delivery to control the invasiveness of MDA-MB-231 breast cancer cells.  


Matrix metalloproteinases (MMPs) have been investigated as a potential target for treating invasive breast cancers. The chemotherapy for breast cancer is often prescribed as a combination of drugs. The present study investigates a novel strategy of combining a MMP inhibitor, Epigallocatechin gallate (EGCG), along with an anticancer drug, Paclitaxel (PTX), in the form of a liposomal co-delivery system. The developed PTX/EGCG co-loaded liposomes showed an entrapment of 77.11±2.30% and 59.11±3.51% for PTX and EGCG, respectively. The in vitro efficacy of the liposomes was assessed by their ability to promote apoptosis and curtail cell invasion. On all parameters, namely cytotoxicity and caspase-3 activity that are indicators of apoptosis, and MMP-2 and - 9 inhibition and invasion assays that are indicators of cell invasion, the PTX/EGCG co-loaded liposomes showed better results than each of the individual drug loaded liposomes. These findings demonstrate the synergistic outcome of PTX/EGCG combination and indicate the suitability of PTX/EGCG co-loaded liposomes for the treatment of invasive breast cancer. PMID:25437065

Ramadass, Satiesh Kumar; Anantharaman, Niranjana Vaighya; Subramanian, Saravanan; Sivasubramanian, Srinivasan; Madhan, Balaraman



In vitro and in vivo characterization of a novel biocompatible polymer–lipid implant system for the sustained delivery of paclitaxel  

Microsoft Academic Search

Recently, a novel chitosan-based implantable formulation (chitosan-ePC) was developed to provide controlled, local release of paclitaxel (PTX) for the treatment of ovarian tumors. Hence, the objective of this study was to evaluate this delivery system in vitro in human ovarian SKOV-3 cells and in vivo in mice with intraperitoneal implants of drug-free or 14C-PTX–chitosan-ePC films. In vitro, 14C-PTX–chitosan-ePC implants (10

Emmanuel A. Ho; Vessela Vassileva; Christine Allen; Micheline Piquette-Miller



A novel biosensor for quantitative monitoring of on-target activity of paclitaxel  

NASA Astrophysics Data System (ADS)

This study describes a system for quantifying paclitaxel activity using the C-terminus of ?-tubulin as a biomarker. Following stabilization of microtubules with paclitaxel, a specific detyrosination reaction occurs at the C-terminus of ?-tubulin which could be used to assess efficacy. A fluorescence resonance energy transfer (FRET) based biosensor was synthesized comprising a short peptide that corresponded to the C-terminus of ?-tubulin, a fluorophore (Abz), and a quencher (Dnp). The fluorophore added to the end of the peptide can be released upon enzymatic detyrosination. In addition, a single fluorophore-tagged peptide was also conjugated to mesoporous silica nanoparticles to examine the feasibility of combining the drug with the peptide biomarker. As a proof of concept, we found that the degree of peptide cleavage, and therefore enzymatic activity, was directly correlated with exogenous bovine carboxypeptidase (CPA) an enzyme that mimics endogenous detyrosination. In addition, we show that cell lysates obtained from paclitaxel-treated cancer cells competed with exogenous CPA for biosensor cleavage in a paclitaxel dose-dependent manner. Our work provides strong evidence for the feasibility of combining paclitaxel with a novel biosensor in a multi-load nanoparticle.This study describes a system for quantifying paclitaxel activity using the C-terminus of ?-tubulin as a biomarker. Following stabilization of microtubules with paclitaxel, a specific detyrosination reaction occurs at the C-terminus of ?-tubulin which could be used to assess efficacy. A fluorescence resonance energy transfer (FRET) based biosensor was synthesized comprising a short peptide that corresponded to the C-terminus of ?-tubulin, a fluorophore (Abz), and a quencher (Dnp). The fluorophore added to the end of the peptide can be released upon enzymatic detyrosination. In addition, a single fluorophore-tagged peptide was also conjugated to mesoporous silica nanoparticles to examine the feasibility of combining the drug with the peptide biomarker. As a proof of concept, we found that the degree of peptide cleavage, and therefore enzymatic activity, was directly correlated with exogenous bovine carboxypeptidase (CPA) an enzyme that mimics endogenous detyrosination. In addition, we show that cell lysates obtained from paclitaxel-treated cancer cells competed with exogenous CPA for biosensor cleavage in a paclitaxel dose-dependent manner. Our work provides strong evidence for the feasibility of combining paclitaxel with a novel biosensor in a multi-load nanoparticle. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr01105h

Townley, H. E.; Zheng, Y.; Goldsmith, J.; Zheng, Y. Y.; Stratford, M. R. L.; Dobson, P. J.; Ahmed, A. A.



Chitosan\\/pshRNA plasmid nanoparticles targeting MDR1 gene reverse paclitaxel resistance in ovarian cancer cells  

Microsoft Academic Search

Summary  In order to investigate the effect of chitosan\\/pshRNA plasmid nanoparticles targeting MDR1 genes on the resistance of A2780\\/TS\\u000a cells to paclitaxel, chitosan\\/pshRNA plasmid nanoparticles were synthesized by means of a complex coacervation technique and\\u000a transfected into A2780\\/TS cells. The cells transfected with MDR1-targeted chitosan\\/pshRNA plasmid nanoparticles were experimental\\u000a cells and the cells transfected with chitosan\\/pGPU6\\/GFP\\/Neo no-load plasmid nanoparticles served as

Yan Yang; Zehua Wang; Minfang Li; Shi Lu



Delivery of paclitaxel from cobalt–chromium alloy surfaces without polymeric carriers  

PubMed Central

Polymer-based carriers are commonly used to deliver drugs from stents. However, adverse responses to polymer coatings have raised serious concerns. This research is focused on delivering drugs from stents without using polymers or any carriers. Paclitaxel (PAT), an anti-restenotic drug, has strong adhesion towards a variety of material surfaces. In this study, we have utilized such natural adhesion property of PAT to attach these molecules directly to cobalt–chromium (Co–Cr) alloy, an ultra-thin stent strut material. Four different groups of drug coated specimens were prepared by directly adding PAT to Co–Cr alloy surfaces: Group-A (PAT coated, unheated, and ethanol cleaned); Group-B (PAT coated, heat treated, and ethanol cleaned); Group-C (PAT coated, unheated, and not ethanol cleaned); and Group-D (PAT coated, heat treated and not ethanol cleaned). In vitro drug release of these specimens was investigated using high performance liquid chromatography. Groups A and B showed sustained PAT release for up to 56 days. A simple ethanol cleaning procedure after PAT deposition can remove the loosely bound drug crystals from the alloy surfaces and thereby allowing the remaining strongly bound drug molecules to be released at a sustained rate. The heat treatment after PAT coating further improved the stability of PAT on Co–Cr alloy and allowed the drug to be delivered at a much slower rate, especially during the initial 7 days. The specimens which were not cleaned in ethanol, Groups C and D, showed burst release. PAT coated Co–Cr alloy specimens were thoroughly characterized using scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. These techniques were collectively useful in studying the morphology, distribution, and attachment of PAT molecules on Co–Cr alloy surfaces. Thus, this study suggests the potential for delivering paclitaxel from Co–Cr alloy surfaces without using any carriers. PMID:20398928

Mani, Gopinath; Macias, Celia E.; Feldman, Marc D.; Marton, Denes; Oh, Sunho; Agrawal, C. Mauli



[Co-delivery of paclitaxel and cyclosporine by a novel liposome-silica hybrid nano-carrier for anti-tumor therapy via oral route].  


In this study, we developed a novel liposome-silica hybrid nano-carrier for tumor combination therapy via oral route, using paclitaxel and cyclosporine as a model drug pair. Optimization of the preparation of the drug-loading formulation and characterization of its physicochemical parameters and drug release profile were performed in vitro. Then in vivo pharmacodynamics and pharmacokinetics studies were performed. The results showed that the obtained formulation has a small particle size (mean diameter of 100.2 +/- 15.2 nm), a homogeneous distribution [the polydispersity index was (0.251 +/- 0.018)] and high encapsulation efficiency (90.15 +/- 2.47) % and (80.64 +/- 3.52) % for paclitaxel and cyclosporine respectively with a mild and easy preparation process. A sequential drug release trend of cyclosporine prior to palictaxel was observed. The liposome-silica hybrid nano-carrier showed good biocompatibility in vivo and co-delivery of cyclosporine and paclitaxel significantly enhanced the oral absorption of paclitaxel with improved anti-tumor efficacy, suggesting a promising approach for multi-drug therapy against tumor and other serious diseases via oral route. PMID:24783515

Deng, Li; Su, Ting-Ting; Huang, Xing-Liang; Wang, Ya-Hua; Li, Chong



miR-145 sensitizes ovarian cancer cells to paclitaxel by targeting Sp1 and Cdk6.  


Multidrug resistance (MDR) remains a major obstacle to effective chemotherapy treatment in ovarian cancer. In our study, paclitaxel-resistant ovarian cancer patients and cell lines had decreased miR-145 levels and expressed high levels of Sp1 and Cdk6. Introducing miR-145 into SKOV3/PTX and A2780/PTX cells led to a reduction in Cdk6 and Sp1 along with downregulation of P-gp and pRb. These changes resulted in increased accumulation of antineoplastic drugs and G1 cell cycle arrest, which rendered the cells more sensitive to paclitaxel in vitro and in vivo. These effects could be reversed by reintroducing Sp1 or Cdk6 into cells expressing high levels of miR-145, resulting in restoration of P-gp and pRb levels. Furthermore, we confirmed that both Cdk6 and Sp1 are targets of miR-145. Intriguingly, demethylation with 5-aza-dC led to reactivation of miR-145 expression in drug-resistant ovarian cancer cell lines, which also resulted in increased sensitivity to paclitaxel. Collectively, these findings begin to elucidate the role of miR-145 as an important regulator of chemoresistance in ovarian cancer by controlling both Cdk6 and Sp1. PMID:24510775

Zhu, Xiaolan; Li, Yuefeng; Xie, Chanjuan; Yin, Xinming; Liu, Yueqin; Cao, Yuan; Fang, Yue; Lin, Xin; Xu, Yao; Xu, Wenlin; Shen, Huiling; Wen, Jian



A novel biosensor for quantitative monitoring of on-target activity of paclitaxel.  


This study describes a system for quantifying paclitaxel activity using the C-terminus of ?-tubulin as a biomarker. Following stabilization of microtubules with paclitaxel, a specific detyrosination reaction occurs at the C-terminus of ?-tubulin which could be used to assess efficacy. A fluorescence resonance energy transfer (FRET) based biosensor was synthesized comprising a short peptide that corresponded to the C-terminus of ?-tubulin, a fluorophore (Abz), and a quencher (Dnp). The fluorophore added to the end of the peptide can be released upon enzymatic detyrosination. In addition, a single fluorophore-tagged peptide was also conjugated to mesoporous silica nanoparticles to examine the feasibility of combining the drug with the peptide biomarker. As a proof of concept, we found that the degree of peptide cleavage, and therefore enzymatic activity, was directly correlated with exogenous bovine carboxypeptidase (CPA) an enzyme that mimics endogenous detyrosination. In addition, we show that cell lysates obtained from paclitaxel-treated cancer cells competed with exogenous CPA for biosensor cleavage in a paclitaxel dose-dependent manner. Our work provides strong evidence for the feasibility of combining paclitaxel with a novel biosensor in a multi-load nanoparticle. PMID:25483994

Townley, H E; Zheng, Y; Goldsmith, J; Zheng, Y Y; Stratford, M R L; Dobson, P J; Ahmed, A A



Therapeutic targeting of erbB3 with MM-121/SAR256212 enhances antitumor activity of paclitaxel against erbB2-overexpressing breast cancer  

PubMed Central

Introduction Elevated expression of erbB3 rendered erbB2-overexpressing breast cancer cells resistant to paclitaxel via PI-3 K/Akt-dependent upregulation of Survivin. It is unclear whether an erbB3-targeted therapy may abrogate erbB2-mediated paclitaxel resistance in breast cancer. Here, we study the antitumor activity of an anti-erbB3 antibody MM-121/SAR256212 in combination with paclitaxel against erbB2-overexpressing breast cancer. Methods Cell growth assays were used to determine cell viability. Cells undergoing apoptosis were quantified by a specific apoptotic ELISA. Western blot analyses were performed to assess the protein expression and activation. Lentiviral vector containing shRNA was used to specifically knockdown Survivin. Tumor xenografts were established by inoculation of BT474-HR20 cells into nude mice. The tumor-bearing mice were treated with paclitaxel and/or MM-121/SAR256212 to determine whether the antibody (Ab) enhances paclitaxel’s antitumor activity. Immunohistochemistry was carried out to study the combinatorial effects on tumor cell proliferation and induction of apoptosis in vivo. Results MM-121 significantly facilitated paclitaxel-mediated anti-proliferative/anti-survival effects on SKBR3 cells transfected with a control vector or erbB3 cDNA. It specifically downregulated Survivin associated with inactivation of erbB2, erbB3, and Akt. MM-121 enhances paclitaxel-induced poly(ADP-ribose) polymerase (PARP) cleavage, activation of caspase-8 and -3, and apoptosis in both paclitaxel-sensitive and -resistant cells. Specific knockdown of Survivin in the trastuzumab-resistant BT474-HR20 cells dramatically enhanced paclitaxel-induced apoptosis, suggesting that increased Survivin caused a cross-resistance to paclitaxel. Furthermore, the studies using a tumor xenograft model-established from BT474-HR20 cells revealed that either MM-121 (10 mg/kg) or low-dose (7.5 mg/kg) paclitaxel had no effect on tumor growth, their combinations significantly inhibited tumor growth in vivo. Immunohistochemical analysis showed that the combinations of MM-121 and paclitaxel significantly reduced the cells with positive staining for Ki-67 and Survivin, and increased the cells with cleaved caspase-3. Conclusions The combinations of MM-121 and paclitaxel not only inhibit tumor cell proliferation, but also promote erbB2-overexpressing breast cancer cells to undergo apoptosis via downregulation of Survivin in vitro and in vivo, suggesting that inactivation of erbB3 with MM-121 enhances paclitaxel-mediated antitumor activity against erbB2-overexpressing breast cancers. Our data supports further exploration of the combinatorial regimens consisting of MM-121 and paclitaxel in breast cancer patients with erbB2-overexpressing tumors, particularly those resistant to paclitaxel. PMID:24168763



Macromolecules in drug delivery Macromolecular targeting agents, carriers, and drugs  

E-print Network

Macromolecules in drug delivery Macromolecular targeting agents, carriers, and drugs #12;Why macromolecules in drug delivery? Classic chemotherapy Drug delivery? Targeting A carrier for small drugs A release mechanism (if necessary) Protection of drug cargo #12;How? 3

Barthelat, Francois


Solid-Nanoemulsion Preconcentrate for Oral Delivery of Paclitaxel: Formulation Design, Biodistribution, and ? Scintigraphy Imaging  

PubMed Central

Aim of present study was to develop a solid nanoemulsion preconcentrate of paclitaxel (PAC) using oil [propylene glycol monocaprylate/glycerol monooleate, 4?:?1?w/w], surfactant [polyoxyethylene 20 sorbitan monooleate/polyoxyl 15 hydroxystearate, 1?:?1?w/w], and cosurfactant [diethylene glycol monoethyl ether/polyethylene glycol 300, 1?:?1?w/w] to form stable nanocarrier. The prepared formulation was characterized for droplet size, polydispersity index, and zeta potential. Transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to assess surface morphology and drug encapsulation and its integrity. Cumulative drug release of prepared formulation through dialysis bag and permeability coefficient through everted gut sac were found to be remarkably higher than the pure drug suspension and commercial intravenous product (Intaxel), respectively. Solid nanoemulsion preconcentrate of PAC exhibited strong inhibitory effect on proliferation of MCF-7 cells in MTT assay. In vivo systemic exposure of prepared formulation through oral administration was comparable to that of Intaxel in ? scintigraphy imaging. Our findings suggest that the prepared solid nanoemulsion preconcentrate can be used as an effective oral solid dosage form to improve dissolution and bioavailability of PAC. PMID:25114933

Ahmad, Javed; Mir, Showkat R.; Kohli, Kanchan; Chuttani, Krishna; Mishra, Anil K.; Panda, A. K.



Solid-nanoemulsion preconcentrate for oral delivery of paclitaxel: formulation design, biodistribution, and ? scintigraphy imaging.  


Aim of present study was to develop a solid nanoemulsion preconcentrate of paclitaxel (PAC) using oil [propylene glycol monocaprylate/glycerol monooleate, 4:1?w/w], surfactant [polyoxyethylene 20 sorbitan monooleate/polyoxyl 15 hydroxystearate, 1:1?w/w], and cosurfactant [diethylene glycol monoethyl ether/polyethylene glycol 300, 1:1?w/w] to form stable nanocarrier. The prepared formulation was characterized for droplet size, polydispersity index, and zeta potential. Transmission electron microscopy (TEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to assess surface morphology and drug encapsulation and its integrity. Cumulative drug release of prepared formulation through dialysis bag and permeability coefficient through everted gut sac were found to be remarkably higher than the pure drug suspension and commercial intravenous product (Intaxel), respectively. Solid nanoemulsion preconcentrate of PAC exhibited strong inhibitory effect on proliferation of MCF-7 cells in MTT assay. In vivo systemic exposure of prepared formulation through oral administration was comparable to that of Intaxel in ? scintigraphy imaging. Our findings suggest that the prepared solid nanoemulsion preconcentrate can be used as an effective oral solid dosage form to improve dissolution and bioavailability of PAC. PMID:25114933

Ahmad, Javed; Mir, Showkat R; Kohli, Kanchan; Chuttani, Krishna; Mishra, Anil K; Panda, A K; Amin, Saima



Simultaneous delivery of therapeutic antagomirs with paclitaxel for the management of metastatic tumors by a pH-responsive anti-microbial peptide-mediated liposomal delivery system.  


The roles of microRNAs (miRNAs) in the regulation of metastasis have been widely recognized in the recent years. Mir-10b antagomir (antagomir-10b) was shown to impede metastasis through the down-regulation of mir-10b; however, it could not stunt the growth of primary tumors. In this study we showed that the co-delivery of antagomir-10b with paclitaxel (PTX) by a novel liposomal delivery system modified with an anti-microbial peptide [D]-H6L9 (D-Lip) could significantly both hinder the migration of 4T1 cells and induce evident cellular apoptosis and cell death in the meantime. The histidines in the sequence of [D]-H6L9 allowed the peptide to get protonated under pH5.0 (mimicking the lysosome/endosome environment), and strong membrane lytic effect could thus be activated, leading to the escape of liposomes from the lysosomes and the decrease of of mir-10b expression. The in vivo and ex vivo fluorescence imaging showed that D-Lip could reach 4T1 tumors efficaciously. Incorporation of PTX did not influence the antagomir-10b delivery effect of D-Lip; for the in vivo tumor inhibition assay, compared with all the other groups, the combination of antagomir-10b and PTX delivered by D-Lip could prominently delay the growth of 4T1 tumors and reduce the lung metastases at the same time, and the expression of Hoxd10 in tumors was also significantly up-regulated. Taken together, these results demonstrated that D-Lip could act as a sufficient tool in co-delivering antagomir-10b and PTX. PMID:25445692

Zhang, Qianyu; Ran, Rui; Zhang, Li; Liu, Yayuan; Mei, Ling; Zhang, Zhirong; Gao, Huile; He, Qin



Targeted estrogen delivery reverses the metabolic syndrome  

PubMed Central

We report the development of a new combinatorial approach that allows for peptide-mediated selective tissue targeting of nuclear hormone pharmacology while eliminating adverse effects in other tissues. Specifically, we report the development of a glucagon-like peptide-1 (GLP-1)-estrogen conjugate that has superior sex-independent efficacy over either of the individual hormones alone to correct obesity, hyperglycemia and dyslipidemia in mice. The therapeutic benefits are driven by pleiotropic dual hormone action to improve energy, glucose and lipid metabolism, as shown by loss-of-function models and genetic action profiling. Notably, the peptide-based targeting strategy also prevents hallmark side effects of estrogen in male and female mice, such as reproductive endocrine toxicity and oncogenicity. Collectively, selective activation of estrogen receptors in GLP-1–targeted tissues produces unprecedented efficacy to enhance the metabolic benefits of GLP-1 agonism. This example of targeting the metabolic syndrome represents the discovery of a new class of therapeutics that enables synergistic co-agonism through peptide-based selective delivery of small molecules. Although our observations with the GLP-1–estrogen conjugate justify translational studies for diabetes and obesity, the multitude of other possible combinations of peptides and small molecules may offer equal promise for other diseases. PMID:23142820

Finan, Brian; Yang, Bin; Ottaway, Nickki; Stemmer, Kerstin; Müller, Timo D; Yi, Chun-Xia; Habegger, Kirk; Schriever, Sonja C; García-Cáceres, Cristina; Kabra, Dhiraj G; Hembree, Jazzminn; Holland, Jenna; Raver, Christine; Seeley, Randy J; Hans, Wolfgang; Irmler, Martin; Beckers, Johannes; de Angelis, Martin Hrab?; Tiano, Joseph P; Mauvais-Jarvis, Franck; Perez-Tilve, Diego; Pfluger, Paul; Zhang, Lianshan; Gelfanov, Vasily; DiMarchi, Richard D; Tschöp, Matthias H



Paclitaxel Injection  


... other medications. Paclitaxel injection manufactured with polyoxyethylated castor oil is used to treat ovarian cancer (cancer that ... and lung cancer. Paclitaxel injection with polyoxyethylated castor oil is also used to treat Kaposi's sarcoma (a ...


Multifunctional Magnetic Nanoparticles for Targeted Delivery  

PubMed Central

A major problem associated with therapy is the inability to deliver pharmaceuticals to a specific site of the body without causing nonspecific toxicity. Development of magnetic nanoparticles and techniques for their safe transport and concentration in specific sites in the body would constitute a powerful tool for gene/drug therapy in vivo. Furthermore, drug delivery in vitro could improve further if the drugs were modified with antibodies, proteins or ligands. For in vivo experiments, magnetic nanoparticles were conjugated with plasmid DNA expressing GFP and then coated with chitosan. These particles were injected into mice through tail vein and directed to heart and kidney by means of external magnets of 25 gauss or 2kA –kA/m. These particles were concentrated in the lungs, heart, and kidney of mice and the expression of GFP in these sites were monitored. The expression of GFP in specific locations was visualized by whole-body fluorescent imaging and the concentration of these particles in the designated body locations was confirmed by transmission electron microscopy. In another model system, we used atrial natriuretic peptide (ANP) and Carcino Embryonic Antigen (CEA) antibodies coupled to the chitosan coated magnetic nanoparticles to target cells in vitro. The present work demonstrates that a simple external magnetic field is all that is necessary to target a drug to a specific site inside the body without the need to functionalize the nanoparticles. However, the option to use magnetic targeting with external magnets on functionalized nanoparticles could prove as a more efficient means of drug delivery. PMID:19446653

Kumar, Arun; Jena, Prasanna K.; Behera, Sumita; Lockey, Richard F.; Mohapatra, Subhra; Mohapatra, Shyam



Synthesis and Evaluation of a Backbone Biodegradable Multiblock HPMA Copolymer Nanocarrier for the Systemic Delivery of Paclitaxel  

PubMed Central

The performance and safety of current antineoplastic agents, particularly water-insoluble drugs, are still far from satisfactory. For example, the currently widely used Cremophor EL®-based paclitaxel (PTX) formulation exhibits pharmacokinetic concerns and severe side effects. Thus, the concept of a biodegradable polymeric drug-delivery system, which can significantly improve therapeutic efficacy and reduce side effects is advocated. The present work aims to develop a new-generation of long-circulating, biodegradable carriers for effective delivery of PTX. First, a multiblock backbone biodegradable N-(2-hydroxypropyl)methacrylamide(HPMA) copolymer- PTX conjugate (mP-PTX) with molecular weight (Mw) of 335 kDa was synthesized by RAFT (reversible addition-fragmentation chain transfer) copolymerization, followed by chain extension. In vitro studies on human ovarian carcinoma A2780 cells were carried out to investigate the cytotoxicity of free PTX, HPMA copolymer-PTX conjugate with Mw of 48 kDa (P-PTX), and mP-PTX. The experiments demonstrated that mP-PTX has a similar cytotoxic effect against A2780 cells as free PTX and P-PTX. To further compare the behavior of this new biodegradable conjugate (mP-PTX) with free PTX and P-PTX in vivo evaluation was performed using female nu/nu mice bearing orthotopic A2780 ovarian tumors. Pharmacokinetics study showed that high Mw mP-PTX was cleared more slowly from the blood than commercial PTX formulation and low Mw P-PTX. SPECT/CT imaging and biodistribution studies demonstrated biodegradability as well as elimination of mP-PTX from the body. The tumors in the mP-PTX treated group grew more slowly than those treated with saline, free PTX, and P-PTX (single dose at 20 mg PTX/kg equivalent). Moreover, mice treated with mP-PTX had no obvious ascites and body-weight loss. Histological analysis indicated that mP-PTX had no toxicity in liver and spleen, but induced massive cell death in the tumor. In summary, this biodegradable drug delivery system has a great potential to improve performance and safety of current antineoplastic agents. PMID:23262201

Zhang, Rui; Luo, Kui; Yang, Jiyuan; Sima, Monika; Sun, Yongen; Janát-Amsbury, Margit M.; Kope?ek, Jind?ich



Hypoxia-targeted siRNA delivery.  


Altered vasculature and the resultant chaotic tumor blood flow lead to the appearance in fast-growing tumors of regions with gradients of oxygen tension and acute hypoxia (less than 1.4% oxygen). Due to its roles in tumorigenesis and resistance to therapy, hypoxia represents a problem in cancer therapy. Insufficient delivery of therapeutic agents to the hypoxic regions in solid tumors is recognized as one of the causes of resistance to therapy. This led to the development of hypoxia imaging agents, and the use of hypoxia-activated anticancer prodrugs. Here we show the first example of the hypoxia-induced siRNA uptake and silencing using a nanocarrier consisting of polyethyleneglycol?2000, azobenzene, polyethyleneimine?(PEI)(1.8?kDa), and 1,2-dioleyl-sn-glycero-3-phosphoethanolamine (DOPE) units (the nanocarrier is referred to as PAPD), where azobenzene imparts hypoxia sensitivity and specificity. We report hypoxia-activated green fluorescent protein (GFP) silencing in vitro and its downregulation in GFP-expressing tumors after intravenous administration. The proposed nanoformulation represents a novel tumor-environment-responsive modality for cancer targeting and siRNA delivery. PMID:24554550

Perche, F; Biswas, S; Wang, T; Zhu, L; Torchilin, V P



Sustained delivery of paclitaxel using thermogelling poly(PEG/PPG/PCL urethane)s for enhanced toxicity against cancer cells.  


A multiblock poly(ether ester urethane)s comprising poly(?-caprolactone), poly(ethylene glycol), and poly(propylene glycol) segments was synthesized. The aqueous copolymer solution exhibited thermogelling behavior at a critical gelation concentration of 3 wt %. The chemical structure and molecular characteristic of the copolymers were studied by gel permeation chromatography, NMR, and fourier transform infrared spectroscopy (FTIR). Rheological characterizations on the thermogel were carried out. Drug release studies using paclitaxel showed that sustained drug release of more than 2 weeks can be achieved with this system. The paclitaxel-loaded gels showed efficiency in the control of the growth of HeLa cells when compared with the paclitaxel dissolved in solution or paclitaxel encapsulated in Pluronics F127. The results demonstrated that the copolymers could be potentially used in chemotherapeutic applications. PMID:22619090

Loh, Xian Jun; Yee, Benjamin Jia Han; Chia, Fu Siong



?-Tocopherol succinate-modified chitosan as a micellar delivery system for paclitaxel: preparation, characterization and in vitro/in vivo evaluations.  


?-Tocopherol succinate hydrophobically modified chitosan (CS-TOS) containing 17 ?-tocopherol groups per 100 anhydroglucose units was synthesized by coupling reaction. The formation of CS-TOS was confirmed by (1)H NMR and FT-IR analysis. In aqueous medium, the polymer could self-aggregate to form micelles, and the critical micelle concentration (CMC) was determined to be 5.8 × 10(-3) mg/ml. Transmission electron microscopy (TEM) observation revealed that both bare and paclitaxel-loaded micelles were near spherical in shape. The mean particle size and zeta potential of drug-loaded micelles were about 78 nm and +25.7 mV, respectively. The results of DSC and XRD analysis indicated that paclitaxel was entrapped in the micelles in molecular or amorphous state. In vitro cytotoxicity and hemolysis study revealed the effectiveness and safety of this delivery system, which was further confirmed by the in vivo antitumor evaluations. It can be concluded that the CS-TOS was a potential micellar carrier for paclitaxel. PMID:22183133

Liang, Na; Sun, Shaoping; Li, Xuefeng; Piao, Hongze; Piao, Hongyu; Cui, Fude; Fang, Liang



Palmitoyl ascorbate-modified liposomes as nanoparticle platform for ascorbate-mediated cytotoxicity and paclitaxel co-delivery.  


Ascorbate has multiple biological roles and chemical interactions, some of which differ between normal and cancerous tissues. Biological effects of ascorbate depend on concentration, route of exposure, and duration of exposure. High-dose ascorbate acts as a pro-oxidant in tissue fluids and delivers peroxide to tissues and fluids, which is then detoxified by erythrocytes and plasma catalase in normally perfused areas. We have previously shown that nanoparticles incorporating palmitoyl ascorbate (PA) targeted and killed cancer cells in vitro. Here, our studies provide additional indications of the importance of extracellular reactive oxygen species (ROS) in the anti-cancer-toxicity by PA-liposomes. Cell death in vitro can be blocked by catalase, superoxide dismutase, and the thiol reductant TCEP. Intracellullar iron may also play a role. Iron chelation by desferrioxamine inhibited cell death but EDTA did not. Further, the fluorescent marker of ROS production in cells indicated that the PA-liposomes caused an increase in ROS. Fluorescent microscopy of tumor sections taken at 3h after injection of rhodamine-labeled liposomes demonstrated an increased accumulation of PA-liposomes compared to plain liposomes. However, the overall biodistribution of (111)In-labeled PA-liposomes was similar to plain liposomes. PA-liposomes provided substantial anti-tumor activity in vivo and enhanced the anti-cancer activity of liposomally encapsulated paclitaxel. Thus, nanoparticles incorporating PA provide a platform for enhancement of the anti-tumor activity of ascorbate. PMID:20433922

Sawant, Rupa R; Vaze, Onkar S; Rockwell, Karen; Torchilin, Vladimir P



Tumor-targeted paclitaxel-loaded folate conjugated poly(ethylene glycol)-poly(L-lactide) microparticles produced by supercritical fluid technology.  


The new biodegradable diblock copolymers poly(ethylene glycol)-poly(L-lactide) (PEG-PLLA) were synthesized and were chemically conjugated with folate (FA) in the PEG terminal ends to form FA-PEG-PLLA. Then the hydrophobic drug paclitaxel (PTX) loaded microparticles (PTX/FA-PEG-PLLA) were produced via solution enhanced dispersion by supercritical fluids (SEDS). These microparticles exhibited sphere-like shape by scanning electron microscopy observation and showed narrow hydrodynamic size distributions by dynamic light scattering measurement. Drug loading of PTX loaded microparticles was about 7-9 % and the encapsulation efficiency of PTX loaded microparticles was about 18-23 %. Flow cytometry and confocal laser scanning microscope analyses revealed that fluorescein isothiocyanate labeled FA conjugated microparticles presented significantly higher cellular uptake than FA-free group due to the FA-receptor-mediated endocytosis. In vitro cytotoxicity evaluation indicated that FA-PEG-PLLA expressed negligible cytotoxicity to mouse fibroblasts L929 cells. Moreover, PTX/FA-PEG-PLLA microparticles exhibited much higher anti-cancer efficacy than PTX/PEG-PLLA microparticles against human ovarian cancer SKOV3 cells. Nude mice xenografted with SKOV3 cells were used in biodistribution studies, the results indicated that an increased amount of PTX was accumulated in the tumor tissue deal with PTX/FA-PEG-PLLA microparticles. These results collectively suggested that PTX/FA-PEG-PLLA microparticles prepared by SEDS would have potential in anti-tumor applications as a tumor-targeted drug delivery formulation. PMID:25649516

Huang, Xiaobei; Zhang, Yanzhi; Yin, Guangfu; Pu, Ximing; Liao, Xiaoming; Huang, Zhongbing; Chen, Xianchun; Yao, Yadong



Toward Intracellular Targeted Delivery of Cancer Therapeutics  

PubMed Central

A number of anti-cancer drugs have their targets localized to particular intracellular compartments. These drugs reach the targets mainly through diffusion, dependent on biophysical and biochemical forces that allow cell penetration. This means that both cancer cells and normal cells will be subjected to such diffusion; hence many of these drugs, like chemotherapeutics, are potentially toxic and the concentration achieved at the site of their action is often suboptimal. The same relates to radiation that indiscriminately affects normal and diseased cells. However, nature-designed systems enable compounds present in the extracellular environment to end up inside the cell and even travel to more specific intracellular compartments. For example, viruses and bacterial toxins can more or less specifically recognize eukaryotic cells, enter these cells, and direct some protein portions to designated intracellular areas. These phenomena have led to creative thinking, such as employing viruses or bacterial toxins for cargo delivery to cells and, more specifically, to cancer cells. Proteins can be genetically engineered in order to not only mimic what viruses and bacterial toxins can do, but also to add new functions, extending or changing the intracellular routes. It is possible to make conjugates or, more preferably, single-chain proteins that recognize cancer cells and deliver cargo inside the cells, even to the desired subcellular compartment. These findings offer new opportunities to deliver drugs/labels only to cancer cells and only to their site of action within the cells. The development of such dual-specificity vectors for targeting cancer cells is an attractive and potentially safer and more efficacious way of delivering drugs. We provide examples of this approach for delivering brain cancer therapeutics, using a specific biomarker on glioblastoma tumor cells. PMID:22671766

Pandya, Hetal; Debinski, Waldemar



Synthesis and Characterization of a Magnetically Responsive Polymeric Drug Delivery System  

E-print Network

A magnetic target drug delivery system consisting of biodegradable polymeric microspheres (poly D, L-lactic acid) loaded with magnetite nanoparticles (10-100 nm) and anticancer drug (paclitaxel) was studied. The magnetite ...

Yu, Shi


miR-16 targets Bcl-2 in paclitaxel-resistant lung cancer cells and overexpression of miR-16 along with miR-17 causes unprecedented sensitivity by simultaneously modulating autophagy and apoptosis.  


Non-small cell lung cancer is one of the most aggressive cancers as per as the mortality and occurrence is concerned. Paclitaxel based chemotherapeutic regimes are now used as an important option for the treatment of lung cancer. However, resistance of lung cancer cells to paclitaxel continues to be a major clinical problem nowadays. Despite impressive initial clinical response, most of the patients eventually develop some degree of paclitaxel resistance in the course of treatment. Previously, utilizing miRNA arrays we reported that downregulation of miR-17 is at least partly involved in the development of paclitaxel resistance in lung cancer cells by modulating Beclin-1 expression [1]. In this study, we showed that miR-16 was also significantly downregulated in paclitaxel resistant lung cancer cells. We demonstrated that anti-apoptotic protein Bcl-2 was directly targeted miR-16 in paclitaxel resistant lung cancer cells. Moreover, in this report we showed that the combined overexpression of miR-16 and miR-17 and subsequent paclitaxel treatment greatly sensitized paclitaxel resistant lung cancer cells to paclitaxel by inducing apoptosis via caspase-3 mediated pathway. Combined overexpression of miR-16 and miR-17 greatly reduced Beclin-1 and Bcl-2 expressions respectively. Our results indicated that though miR-17 and miR-16 had no common target, both miR-16 and miR-17 jointly played roles in the development of paclitaxel resistance in lung cancer. miR-17 overexpression reduced cytoprotective autophagy by targeting Beclin-1, whereas overexpression of miR-16 potentiated paclitaxel induced apoptotic cell death by inhibiting anti-apoptotic protein Bcl-2. PMID:25435430

Chatterjee, Abhisek; Chattopadhyay, Dhrubajyoti; Chakrabarti, Gopal



J Drug Target . Author manuscript Targeted delivery of a proapoptotic peptide to tumors in vivo  

E-print Network

J Drug Target . Author manuscript Page /1 10 Targeted delivery of a proapoptotic peptide to tumors of perfectly controlled, targeted drug delivery systems. Author Keywords drug vectorization ; cancer ; integrin for tumour imaging and drug targeting. We designed the molecule RAFT-(c -RGDfK- ) , a constrained

Boyer, Edmond


Giant Fullerenes for Target Specific Drug Delivery  

NASA Astrophysics Data System (ADS)

Carbon nano-structures, such as giant fullerenes, have a great potential for biological and medical applications. Most of the previous research is dedicated to investigate the use of fullerenes as vehicles for carrying medication which is chemisorbed on the outside surface of the fullerenes. In contrast, using fullerenes as an enclosure was largely abandoned due to the high strength of the carbon-carbon bonds which has been perceived to prevent the rupturing of the fullerene to release their cargo. We performed atomistic computations based on classical force fields that will address this perception. Specifically we explore the physics and chemistry of OH functionalized carbon based giant fullerenes with diameters from 0.72 nm (60 atoms) to 5.7 nm (3840 atoms). The preliminary results show that OH functionalization on these fullerenes is not only viable but also provides a pH sensitive release mechanism. Furthermore our current results show that carbon-carbon bonds can be broken in low energy biological environments in the presence of a flow induced strain field. These insights may have implications for target specific drug delivery in general and cancer treatment in particular.

Courtney, Robert; Kiefer, Boris



Nanoparticle-based targeted drug delivery  

PubMed Central

Nanotechnology could be defined as the technology that has allowed for the control, manipulation, study, and manufacture of structures and devices in the “nanometer” size range. These nano-sized objects, e.g., “nanoparticles”, take on novel properties and functions that differ markedly from those seen from items made of identical materials. The small size, customized surface, improved solubility, and multi-functionality of nanoparticles will continue to open many doors and create new biomedical applications. Indeed, the novel properties of nanoparticles offer the ability to interact with complex cellular functions in new ways. This rapidly growing field requires cross-disciplinary research and provides opportunities to design and develop multifunctional devices that can target, diagnose, and treat devastating diseases such as cancer. This article presents an overview of nanotechnology for the biologist and discusses the attributes of our novel XPclad© nanoparticle formulation that has shown efficacy in treating solid tumors, for single dose vaccination, and oral delivery of therapeutic proteins. PMID:19186176

Singh, Rajesh; Lillard, James W.



The Na+/H+ exchanger (NHE1) as a novel co-adjuvant target in paclitaxel therapy of triple-negative breast cancer cells.  


Dysregulation of Na+/H+ exchanger isoform one (NHE1) activity is a hallmark of cells undergoing tumorigenesis and metastasis, the leading cause of patient mortality. The acidic tumor microenvironment is thought to facilitate the development of resistance to chemotherapy drugs and to promote extracellular matrix remodeling leading to metastasis. Here, we investigated NHE1 as a co-adjuvant target in paclitaxel chemotherapy of metastatic breast cancer. We generated a stable NHE1-knockout of the highly invasive, triple-negative, MDA-MB-231 breast cancer cells. The NHE1-knockout cells proliferated comparably to parental cells, but had markedly lower rates of migration and invasion in vitro. In vivo xenograft tumor growth in athymic nude mice was also dramatically decreased compared to parental MDA-MB-231 cells. Loss of NHE1 expression also increased the susceptibility of knockout cells to paclitaxel-mediated cell death. NHE1 inhibition, in combination with paclitaxel, resulted in a dramatic decrease in viability, and migratory and invasive potential of triple-negative breast cancer cells, but not in hormone receptor-positive, luminal MCF7 cells. Our data suggest that NHE1 is critical in triple-negative breast cancer metastasis, and its chemical inhibition boosts the efficacy of paclitaxel in vitro, highlighting NHE1 as a novel, potential co-adjuvant target in breast cancer chemotherapy. PMID:25514463

Amith, Schammim Ray; Wilkinson, Jodi Marie; Baksh, Shairaz; Fliegel, Larry



Nanoparticles of star-like copolymer mannitol-functionalized poly(lactide)-vitamin E TPGS for delivery of paclitaxel to prostate cancer cells.  


The purpose of this research was to develop novel nanoparticles (NPs) of star-like copolymer mannitol-functionalized poly(lactide)-vitamin E TPGS (M-PLA-TPGS) for paclitaxel delivery for prostate cancer treatment, and evaluate their therapeutic effects in prostate cancer cell line and animal model in comparison with the linear PLGA NPs and poly(lactide)-vitamin E TPGS (PLA-TPGS) NPs. The paclitaxel-loaded M-PLA-TPGS NPs, prepared by a modified nano-precipitation method, were observed by FESEM to be near-spherical shape with narrow size distribution. The drug-loaded NPs were further characterized in terms of size, surface charge, drug content, encapsulation efficiency and in vitro drug release. The results showed that the M-PLA-TPGS NPs were found to be stable, showing almost no change in particle size and surface charge during the three-month storage period. In vitro drug release exhibited biphasic pattern with initial burst release followed by slow and continuous release. The cellular uptake level of M-PLA-TPGS NPs was demonstrated higher than linear PLGA NPs and PLA-TPGS NPs in PC-3 cells. The data also showed that the paclitaxel-loaded M-PLA-TPGS nanoparticles have higher antitumor efficacy than that of linear PLA-TPGS nanoparticles and PLGA nanoparticles in vitro and in vivo. In summary, the star-like copolymer M-PLA-TPGS could be used as a potential and promising molecular biomaterial in developing novel nanoformulation for prostate cancer treatment. PMID:24621530

Wang, Kebing; Guo, Longhua; Xiong, Wei; Sun, Leilei; Zheng, Yi



Expert Review Functionalized Micellar Systems for Cancer Targeted Drug Delivery  

E-print Network

Expert Review Functionalized Micellar Systems for Cancer Targeted Drug Delivery Damon Sutton,1, and general use of micelles as drug delivery systems (4Y13). The purpose of this review is to provide stability, ability to solubilize water insoluble anticancer drugs, and prolonged blood circulation times

Gao, Jinming


Poly(ethylene oxide)-modified poly(beta-amino ester) nanoparticles as a pH-sensitive biodegradable system for paclitaxel delivery.  


The main objective of this study was to develop and characterize a pH-sensitive biodegradable polymeric nanoparticulate system for tumor-selective paclitaxel delivery. A representative hydrophobic poly(beta-amino ester) (poly-1) was synthesized by conjugate addition of 4,4'-trimethyldipiperidine with 1,4-butanediol diacrylate. Poly-1 (M(n) 10,000 daltons) nanoparticles were prepared by the controlled solvent displacement method in an ethanol-water system in the presence of Pluronic) F-108, a poly(ethylene oxide) (PEO)-containing non-ionic surfactant. Control and PEO-modified nanoparticles were characterized by Coulter counter, scanning electron microscopy (SEM), zeta potential measurements, and electron spectroscopy for chemical analysis (ESCA). Polymer degradation studies were performed in phosphate-buffered saline (PBS, pH 7.4) at 37 degrees C. Paclitaxel loading capacities and efficiencies were determined and release studies were performed in Tween)-80 (0.1%, w/v)-containing PBS at 37 degrees C. Control and PEO-modified nanoparticles, labeled with rhodamine-123, were incubated with BT-20 cells to examine the uptake and cellular distribution as a function of time. PEO-modified nanoparticles with an average size of 100-150 nm and a positive surface charge of 37.0 mV were prepared. SEM analysis showed distinct smooth, spherical particles. The ether (-C-O-) peak of the C(1s) envelope in ESCA confirmed the surface presence of PEO chains. Polymer biodegradation studies showed that almost 85% of the starting material degraded after 6 days. The maximum paclitaxel loading efficiency attained was 97% at 1.0% (w/w) of the drug. Paclitaxel release studies showed that approximately 10% was released in the first 24 h, 80% after 3 days, and the entire content was released in approximately 5 days. After 1 h of incubation, a large fraction of the administered control and PEO-modified poly-1 nanoparticles was internalized in BT-20 cells. Results of this study demonstrate that PEO-modified poly-1 nanoparticles could provide increased therapeutic benefit by delivering the encapsulated drug to solid tumors. PMID:12526819

Potineni, Anupama; Lynn, David M; Langer, Robert; Amiji, Mansoor M



Colon targeted delivery systems: review of polysaccharides for encapsulation and delivery.  


Colon-targeted delivery of bioactives has recently gained importance in addressing specific needs in the therapy of colon-based diseases. Many approaches have been attempted for the development of colon-specific delivery systems, with not much success in the past. Recent research into the utilization of the metabolic activity and the colonic microenvironment in the lower gastrointestinal tract has attained great value in the design of novel colon-targeted delivery systems based on natural biodegradable polymers. In the current article, special emphasis has been placed on polysaccharide systems, with minimal chemical modification, that have been exploitedfor colon targeting. These polysaccharide based encapsulation and targeted delivery systems are envisaged to have an immense potential for the development of food/nutraceutical formulations for colon-based diseases, including colorectal cancer. PMID:16047493

Kosaraju, Shantha L



Subcellular targeting strategies for drug design and delivery  

Microsoft Academic Search

Many drug targets are localized to particular subcellular compartments, yet current drug design strategies are focused on bioavailability and tissue targeting and rarely address drug delivery to specific intracellular compartments. Insights into how the cell traffics its constituents to these different cellular locations could improve drug design. In this Review, we explore the fundamentals of membrane trafficking and subcellular organization,

Lawrence Rajendran; Hans-Joachim Knölker; Kai Simons



Polymer- and liposome-based nanoparticles in targeted drug delivery.  


This review focuses on polymer- and liposome-based nanoparticles used in targeted delivery of bioactive molecules, from drugs to siRNA to pDNA. The perspective centers around commercial and clinical successes, and a rationalization of these successes. Microparticulate systems are not covered, and only those applications that truly utilize the advantages of nano size are covered. "Stealth" systems dominate in this review, as most of the clinical successes are for passive targeting rather than for active targeting of tissue. The relevance of nano size to gene delivery is also discussed with relevant examples. PMID:20515826

Venkatraman, Subbu S; Ma, Lwin Lwin; Natarajan, Jayaganesh V; Chattopadhyay, Sujay



Targeted delivery systems for biological therapies of inflammatory diseases.  


Introduction: Inflammatory diseases, including autoimmune diseases and autoinflammatory diseases, are characterized by the imbalance of pro-inflammatory cytokines and anti-inflammatory cytokines. Targeted systems allow for specific delivery and sustained release of biological agents to inflamed tissues and macrophages, hence reducing their side effects. Areas covered: This review discusses various targeting strategies for biological therapies of inflammatory diseases, with a focus on modulating macrophage functional polarization from an M1 to M2 phenotype. Furthermore, recent advances in the development of targeted delivery systems for gene therapy against inflammatory diseases including liposomal therapeutics, polymeric nanoparticles and microspheres, and multi-compartmental delivery systems are summarized. Expert opinion: Molecular advances have uncovered various targets for biological therapies against inflammatory diseases. Despite substantial promise, the potential translation from the bench to the clinic is limited due to poor systemic stability of the delivery systems, low tissue distribution, and safety concerns. In order to develop clinically translatable targeted delivery systems, thorough evaluation of the efficacy and toxicity in relevant animal models and in different inflammatory diseases is needed. In addition, issues related to long-term storage stability, scale-up and manufacturing of the systems need to be addressed. PMID:25366552

Tran, Thanh-Huyen; Amiji, Mansoor M



Increased antitumor activity, intratumor paclitaxel concentrations, and endothelial cell transport of cremophor-free, albumin-bound paclitaxel, ABI-007, compared with cremophor-based paclitaxel.  


ABI-007, an albumin-bound, 130-nm particle form of paclitaxel, was developed to avoid Cremophor/ethanol-associated toxicities in Cremophor-based paclitaxel (Taxol) and to exploit albumin receptor-mediated endothelial transport. We studied the antitumor activity, intratumoral paclitaxel accumulation, and endothelial transport for ABI-007 and Cremophor-based paclitaxel. Antitumor activity and mortality were assessed in nude mice bearing human tumor xenografts [lung (H522), breast (MX-1), ovarian (SK-OV-3), prostate (PC-3), and colon (HT29)] treated with ABI-007 or Cremophor-based paclitaxel. Intratumoral paclitaxel concentrations (MX-1-tumored mice) were compared for radiolabeled ABI-007 and Cremophor-based paclitaxel. In vitro endothelial transcytosis and Cremophor inhibition of paclitaxel binding to cells and albumin was compared for ABI-007 and Cremophor-based paclitaxel. Both ABI-007 and Cremophor-based paclitaxel caused tumor regression and prolonged survival; the order of sensitivity was lung > breast congruent with ovary > prostate > colon. The LD(50) and maximum tolerated dose for ABI-007 and Cremophor-based paclitaxel were 47 and 30 mg/kg/d and 30 and 13.4 mg/kg/d, respectively. At equitoxic dose, the ABI-007-treated groups showed more complete regressions, longer time to recurrence, longer doubling time, and prolonged survival. At equal dose, tumor paclitaxel area under the curve was 33% higher for ABI-007 versus Cremophor-based paclitaxel, indicating more effective intratumoral accumulation of ABI-007. Endothelial binding and transcytosis of paclitaxel were markedly higher for ABI-007 versus Cremophor-based paclitaxel, and this difference was abrogated by a known inhibitor of endothelial gp60 receptor/caveolar transport. In addition, Cremophor was found to inhibit binding of paclitaxel to endothelial cells and albumin. Enhanced endothelial cell binding and transcytosis for ABI-007 and inhibition by Cremophor in Cremophor-based paclitaxel may account in part for the greater efficacy and intratumor delivery of ABI-007. PMID:16489089

Desai, Neil; Trieu, Vuong; Yao, Zhiwen; Louie, Leslie; Ci, Sherry; Yang, Andrew; Tao, Chunlin; De, Tapas; Beals, Bridget; Dykes, Donald; Noker, Patricia; Yao, Rosie; Labao, Elizabeth; Hawkins, Michael; Soon-Shiong, Patrick



Targeted Nanomedicine for Suppression of CD44 and Simultaneous Cell Death Induction in Ovarian Cancer: an Optimal Delivery of siRNA and Anticancer Drug  

PubMed Central

Purpose: The proposed project is aimed at enhancing the efficiency of epithelial ovarian cancer treatment and reducing adverse side effects of chemotherapy using nanotechnology. Overexpression of the CD44 membrane receptor results in tumor initiation, growth, tumor stem cells specific behavior, development of drug resistance, and metastases. We hypothesize that a developed cancer targeted delivery system which combines CD44 siRNA with paclitaxel would successfully deliver its payload inside cancer cells, effectively induce cell death, and prevent metastases. Experimental Design: We synthesized, characterized, and tested a nanoscale-based drug delivery system containing a modified Polypropylenimine (PPI) dendrimer as a carrier; anticancer drug paclitaxel as a cell death inducer; a synthetic analog of luteinizing hormone-releasing hormone (LHRH) peptide as a tumor targeting moiety, and siRNA targeted to CD44 mRNA. The proposed NDDS was tested in vitro and in vivo using metastatic ovarian cancer cells isolated from patients with malignant ascites. Results: We found that in contrast to cells isolated from primary tumors, CD44 was highly overexpressed in metastatic cancer cells. Treatment with the proposed tumor-targeted nanoscale-based nucleic acid and drug delivery system led to the suppression of CD44 mRNA and protein, efficient induction of cell death, effective tumor shrinkage, and prevention of adverse side effects on healthy organs. Conclusion: We show a high therapeutic potential for combinatorial treatment of ovarian carcinoma with a novel drug delivery system that effectively transports siRNA targeting to CD44 mRNA simultaneously with cytotoxic agents. PMID:24036854

Shah, Vatsal; Taratula, Oleh; Garbuzenko, Olga B.; Taratula, Olena R.; Rodriguez-Rodriguez, Lorna; Minko, Tamara



Functionalized nanosystems for targeted mitochondrial delivery.  


Mitochondrial dysfunction including oxidative stress and DNA mutations underlies the pathology of various diseases including Alzheimer's disease and diabetes, necessitating the development of mitochondria targeted therapeutic agents. Nanotechnology offers unique tools and materials to target therapeutic agents to mitochondria. As discussed in this paper, a variety of functionalized nanosystems including polymeric and metallic nanoparticles as well as liposomes are more effective than plain drug and non-functionalized nanosystems in delivering therapeutic agents to mitochondria. Although the field is in its infancy, studies to date suggest the superior therapeutic activity of functionalized nanosystems for treating mitochondrial defects. PMID:22138492

Durazo, Shelley A; Kompella, Uday B



Cell-Specific Aptamer-Mediated Targeted Drug Delivery  

PubMed Central

Nucleic acid aptamers are in vitro-selected small, single-stranded DNA or RNA oligonucleotides that can specifically recognize their target on the basis of their unique 3-dimensional structures. Recent advances in the development of escort aptamers to deliver and enhance the efficacy of other therapeutic agents have drawn enthusiasm in exploiting cell-type-specific aptamers as drug delivery vehicles. This review mainly focuses on the recent developments of aptamer-mediated targeted delivery systems. We also place particular emphasis on aptamers evolved against cell membrane receptors and possibilities for translation to clinical applications. PMID:21182455

Zhou, Jiehua



Supramolecular self-assembly forming a multifunctional synergistic system for targeted co-delivery of gene and drug.  


For developing a multifunctional bioreducible targeted and synergistic co-delivery system for anticancer drug paclitaxel (PTX) and p53 gene for potential cancer therapy, supramolecular self-assembled inclusion complex was prepared from PTX and star-shaped cationic polymer containing ?-cyclodextrin (?-CD) and multiple oligoethylenimine (OEI) arms with folic acid (FA) conjugated via a disulfide linker. The inclusion complex, termed as ?-CD-OEI-SS-FA/PTX, was formed between PTX and the hydrophobic cavity of ?-CD core of the star polymer. The ?-CD-OEI-SS-FA/PTX complex further formed polyplexes with pDNA to give positively charged nanoparticles, becoming multifunctional supramolecular self-assembled co-delivery system for PTX and pDNA targeting to cancer cells that overexpress folate receptors (FRs). The results showed that the FA-targeted function induced higher gene transfection efficiency in the FR-positive KB cells. The redox-sensitive disulfide linker in the self-assembly system led to the detachment of the FA groups from the carrier after the FR-mediated endocytosis, which resulted in the release of the bound FRs followed by the recycling of the FRs from the cytosol onto the cell membrane surface, facilitating continuous FR-mediated endocytosis to achieve enhanced gene transfection. In addition, the complexed PTX was co-delivered to the cells with pDNA, which further enhanced the gene transfection even at low N/P ratios in the FR-positive KB cells. Further, the efficient delivery of wild-type p53 gene resulted in large cell population at sub G1 and G2/M phases, inducing significant cell apoptosis. Therefore, the multifunctional ?-CD-OEI-SS-FA/PTX self-assembly system with the synergistic effects of redox-sensitive FA-targeted and PTX-enhanced p53 gene delivery may be promising for cancer therapeutic application. PMID:24189097

Zhao, Feng; Yin, Hui; Li, Jun



Liposomes surface conjugated with human hemoglobin target delivery to macrophages  

PubMed Central

Current strategies to deliver therapeutic molecules to specific cell and tissue types rely on conjugation of antibodies and other targeting ligands directly to the therapeutic molecule itself or its carrier. This work describes a novel strategy to deliver therapeutic molecules into macrophages that takes advantage of the native hemoglobin (Hb) scavenging activity of plasma haptoglobin (Hp) and the subsequent uptake of the Hb-Hp complex into macrophages via CD163 receptor mediated endocytosis. The drug delivery system described in this work consists of hemoglobin decorated liposomes that can encapsulate any therapeutic molecule of interest, in this case the model fluorescent dye calcein was used in this study. The results of this study clearly demonstrate that this delivery system is specific towards macrophages and demonstrates the feasibility of using this approach in targeted drug delivery. PMID:22012493

Zhang, Ning; Palmer, Andre F.



Targeted Delivery of Radioprotective Agents to Mitochondria  

PubMed Central

Adverse effects of ionizing radiation are mediated through reactive oxygen and nitrogen species. Mitochondria are the principal source of these species in the cell and play an important role in irradiation-induced apoptosis. The use of free radical scavengers and nitric oxide synthase inhibitors has proven to protect normal tissues and, in some cases, to sensitize tumor tissues to radiation damage. Dual molecules that combine radical-scavenging and NOS-inhibitory functions may be particularly effective. Drugging strategies that target mitochondria can enhance the effectiveness of such agents, in comparison to systemic administration, and circumvent side effects. PMID:19144902

Zabbarova, Irina; Kanai, Anthony



Self-Assembling Peptide Amphiphiles for Targeted Drug Delivery  

NASA Astrophysics Data System (ADS)

The systemic delivery of therapeutics is currently limited by off-target side effects and poor drug uptake into the cells that need to be treated. One way to circumvent these issues is to target the delivery and release of therapeutics to the desired location while limiting systemic toxicity. Using self-assembling peptide amphiphiles (PAs), this work has investigated supramolecular nanostructures for the development of targeted therapies. Specifically, the research has focused on the interrelationships between presentation of targeting moeities and the control of nanostructure morphology in the context of systemic delivery for targeting cancer and vascular injuries. The self-assembly region of the PA was systematically altered to achieve control of nanostructure widths, from 100 nm to 10 nm, by the addition of valine-glutamic acid dimers into the chemical structure, subsequently increasing the degree of nanostructure twist. For the targeting of tumors, a homing PA was synthesized to include a dimeric, cyclic peptide sequence known to target the cancer-specific, death receptor 5 (DR5) and initiate apoptosis through the oligomerization of DR5. This PA presented a multivalent display of DR5-binding peptides, resulting in improved binding affinity measured by surface plasmon resonance. The DR5-targeting PA also showed enhanced efficacy in both in vitro and in vivo tumor models relative to non-targeted controls. Alternative modifications to the PA-based antitumor therapies included the use of a cytotoxic, membrane-lytic PA coassembled with a pegylated PA, which showed enhanced biodistribution and in vivo activity after coassembly. The functionalization of the hydrophobic core was also accomplished through the encapsulation of the chemotherapy camptothecin, which was shown to be an effective treatment in vivo. Additionally, a targeted PA nanostructure was designed to bind to the site of vascular intervention by targeting collagen IV. Following balloon angioplasty, targeted PA nanofibers showed enhanced binding by fluorescence relative to spherical micelles with the same targeting sequence, demonstrating the importance of nanostructure shape for vascular binding. Nitric oxide was functionalized onto the PA nanostructure through the S-nitrosylation (SNO) of a cysteine residue. Two weeks after vascular injury, the SNO-functionalized, targeted nanofibers showed significantly decreased levels of restenosis. In all treatment methods described, the control of multivalency through the tuning of supramolecular structure was essential to achieve optimal binding. Understanding the role of dynamic, supramolecular structures for the systemic delivery of peptide therapeutics should be an important focus of future work.

Moyer, Tyson


Tetraspecific ligand for tumor-targeted delivery of nanomaterials.  


The polygenetic nature of most cancers emphasizes the necessity of cancer therapies that target multiple essential signaling pathways. However, there is a significant paucity of targeting ligands with multi-specificities for targeted delivery of biomaterials. To address this unmet need, we generated a tetraspecific targeting ligand that recognizes four different cancer biomarkers, including VEGFR2, ?v?3 integrin, EGFR, and HER2 receptors, which have been implicated in numerous malignant tumors. The tetraspecific targeting ligand was constructed by sequentially connecting four targeting ligand subunits via flexible linkers, yielding a fusion protein that can be highly expressed in Escherichia coli and readily purified to near homogeneity. Surface Plasmon Resonance (SPR), Bio-Layer Interferometry (BLI) studies and extensive cellular binding analyses indicated that all the targeting ligand subunits in the tetraspecific fusion protein recognized their target receptors proximately to the corresponding monospecific ligands. The resulting tetraspecific targeting ligand was applied for the delivery of nanomaterials such as gold nanoparticles (AuNPs) for targeted hyperthermic killing of various cancer cell lines with biomarkers of interest expressed. We demonstrate that the tetraspecific ligand can be facilely introduced on the surface of AuNPs and efficient target-dependent killing of cancer cells can be achieved only when the AuNPs are conjugated with the tetraspecific ligand. Significantly, the tetraspecific ligand simultaneously interacts with more than one receptors, such as EGFR and HER2 receptors, when they are expressed on the surface of the same cell, as demonstrated by in vitro binding assays and cell binding analyses. Our results demonstrate that the tetraspecific ligand, through multivalency and synergistic binding, can be readily used to generate various 'smart' biomaterials with greatly broadened tumor targeting range for simultaneous targeting of multiple signaling pathways on many different cancer types. PMID:24786763

Kim, Dongwook; Friedman, Adam D; Liu, Rihe



Antitumor drug Paclitaxel-loaded pH-sensitive nanoparticles targeting tumor extracellular pH  

Microsoft Academic Search

Research efforts have been devoted to demonstrating that the pH-sensitive characteristics of poly NIPAAm\\/chitosan nanoparticles can be applied to targeting tumors. A copolymer of (NIPAAm) and chitosan (4:1, m\\/m) was synthesized, and its drug release characteristics investigated. The results revealed that drug-loaded nanoparticles which encapsulation and loading efficiencies were 85.7% and 9.6%, respectively, exhibited pH-sensitive responses to tumor pH. The

Fan Li; Hong Wu; Hui Zhang; Fei Li; Chun-hu Gu; Qian Yang



Targeted Decationized Polyplexes for siRNA Delivery.  


The applicability of small interfering RNA (siRNA) in future therapies depends on the availability of safe and efficient carrier systems. Ideally, siRNA delivery requires a system that is stable in the circulation but upon specific uptake into target cells can rapidly release its cargo into the cytoplasm. Previously, we evaluated a novel generation of carrier systems ("decationized" polyplexes) for DNA delivery, and it was shown that folate targeted decationized polyplexes had an excellent safety profile and showed intracellular triggered release upon cell specific uptake. Targeted decationized polyplexes consist of a core of disulfide cross-linked poly(hydroxypropyl methacrylamide) (pHPMA) stably entrapping nucleic acids and a shell of poly(ethylene glycol) (PEG) decorated with folate molecules. In the present study, the applicability of folate targeted decationized polyplexes for siRNA delivery was investigated. This required optimization of the carrier system particularly regarding the cross-linking density of the core of the polyplexes. Stable and nanosized siRNA decationized polyplexes were successfully prepared by optimizing the cross-link density of their core. Upon incubation in human plasma, a significant portion of siRNA remained entrapped in the decationized polyplexes as determined by fluorescence correlation spectroscopy (FCS). When tested in a folate receptor overexpressing cell line stably expressing luciferase, Skov3-luc, sequence specific gene silencing was observed. As expected, neither interference on the intrinsic luciferase expression nor on the cell metabolic activity (determined by XTT) was induced by the free-polymer or the siRNA polyplexes. In conclusion, targeted decationized polyplexes are safe and stable carriers that interact with the targeted cells and rapidly disassemble upon cell entry making them promising siRNA delivery systems. PMID:25384057

Novo, Luís; Takeda, Kaori M; Petteta, Tamara; Dakwar, George R; van den Dikkenberg, Joep B; Remaut, Katrien; Braeckmans, Kevin; van Nostrum, Cornelus F; Mastrobattista, Enrico; Hennink, Wim E



Pharmacytes: an ideal vehicle for targeted drug delivery.  


An ideal nanotechnology-based drug delivery system is a pharmacyte--a self-powered, computer-controlled medical nanorobot system capable of digitally precise transport, timing, and targeted delivery of pharmaceutical agents to specific cellular and intracellular destinations within the human body. Pharmacytes may be constructed using future molecular manufacturing technologies such as diamond mechanosynthesis which are currently being investigated theoretically using quantum ab initio and density-functional computational methods. Pharmacytes will have many applications in nanomedicine such as initiation of apoptosis in cancer cells and direct control of cell signaling processes. PMID:17048481

Freitas, Robert A



Targeted Liposomal Drug Delivery to Monocytes and Macrophages  

PubMed Central

As the role of monocytes and macrophages in a range of diseases is better understood, strategies to target these cell types are of growing importance both scientifically and therapeutically. As particulate carriers, liposomes naturally target cells of the mononuclear phagocytic system (MPS), particularly macrophages. Loading drugs into liposomes can therefore offer an efficient means of drug targeting to MPS cells. Physicochemical properties including size, charge and lipid composition can have a very significant effect on the efficiency with which liposomes target MPS cells. MPS cells express a range of receptors including scavenger receptors, integrins, mannose receptors and Fc-receptors that can be targeted by the addition of ligands to liposome surfaces. These ligands include peptides, antibodies and lectins and have the advantages of increasing target specificity and avoiding the need for cationic lipids to trigger intracellular delivery. The goal for targeting monocytes/macrophages using liposomes includes not only drug delivery but also potentially a role in cell ablation and cell activation for the treatment of conditions including cancer, atherosclerosis, HIV, and chronic inflammation. PMID:21512579

Kelly, Ciara; Jefferies, Caroline; Cryan, Sally-Ann



Paclitaxel (Taxol)--a guide to administration.  


The introduction of a new chemotherapeutic agent has implications for nursing care. Paclitaxel (Taxol) chemotherapy is now being used throughout Europe for treatment of patients with ovarian cancer who have previously failed a platinum-containing chemotherapy regimen, and in many countries to treat metastatic breast cancer. Nurses need to be equipped to care for these patients receiving Paclitaxel. This paper introduces nurses to Paclitaxel, the history of its development, its mechanism of action, potential side-effects and administration. Paclitaxel's side-effects include hypersensitivity reactions, neutropaenia, peripheral neuropathy, asymptomatic bradycardia, alopecia, malaise, myalgias and arthralgias. Administration guidelines will be discussed because Paclitaxel leaches plasticizer from polyvinyl chloride (PVC) intravenous-giving sets normally used to administer chemotherapy, hence an alternative delivery system is required. PMID:9117048

Preston, N J



Polysaccharide-Gold Nanocluster Supramolecular Conjugates as a Versatile Platform for the Targeted Delivery of Anticancer Drugs  

PubMed Central

Through the high affinity of the ?-cyclodextrin (?-CD) cavity for adamantane moieties, novel polysaccharide-gold nanocluster supramolecular conjugates (HACD-AuNPs) were successfully constructed from gold nanoparticles (AuNPs) bearing adamantane moieties and cyclodextrin-grafted hyaluronic acid (HACD). Due to their porous structure, the supramolecular conjugates could serve as a versatile and biocompatible platform for the loading and delivery of various anticancer drugs, such as doxorubicin hydrochloride (DOX), paclitaxel (PTX), camptothecin (CPT), irinotecan hydrochloride (CPT-11), and topotecan hydrochloride (TPT), by taking advantage of the controlled association/dissociation of drug molecules from the cavities formed by the HACD skeletons and AuNPs cores as well as by harnessing the efficient targeting of cancer cells by hyaluronic acid. Significantly, the release of anticancer drugs from the drug@HACD-AuNPs system was pH-responsive, with more efficient release occurring under a mildly acidic environment, such as that in a cancer cell. Taking the anticancer drug DOX as an example, cell viability experiments revealed that the DOX@HACD-AuNPs system exhibited similar tumor cell inhibition abilities but lower toxicity than free DOX due to the hyaluronic acid reporter-mediated endocytosis. Therefore, the HACD-AuNPs supramolecular conjugates may possess great potential for the targeted delivery of anticancer drugs. PMID:24566666

Li, Nan; Chen, Yong; Zhang, Ying-Ming; Yang, Yang; Su, Yue; Chen, Jia-Tong; Liu, Yu



A co-delivery system based on paclitaxel grafted mPEG-b-PLG loaded with doxorubicin: preparation, in vitro and in vivo evaluation.  


Herein, we develop a co-delivery system of paclitaxel (PTX) and doxorubicin hydrochloride (DOX·HCl) based on methoxypoly(ethylene glycol)-block-poly(L-glutamic acid) (mPEG-b-PLG) for cancer treatment. PTX was grafted to the mPEG-b-PLG by esterification to give mPEG-b-PLG-g-PTX. DOX·HCl was encapsulated via electrostatic interaction and hydrophobic stack between the DOX·HCl and mPEG-b-PLG-g-PTX in aqueous solution. The release rate of DOX·HCl from the drug-loaded nanoparticles (mPEG-b-PLG-g-PTX-DOX) was slow at blood pH (pH 7.4), but obviously increased at endosome pH (pH 5.4). The mPEG-b-PLG-g-PTX-DOX exhibited slight synergistic effect in inhibition of proliferation of A549 and MCF-7 human cancer cells. For in vivo treatment of xenograft human breast tumor (MCF-7), the mPEG-b-PLG-g-PTX-DOX nanoparticles exhibited remarkable tumor inhibition effect with a 95.5% tumor-suppression-rate which was significantly higher than those of related single anticancer agents such as free DOX·HCl and mPEG-b-PLG-g-PTX. These results indicated that the mPEG-b-PLG-g-PTX-DOX would have great potential in cancer therapy. PMID:24905776

Li, Qian; Lv, Shixian; Tang, Zhaohui; Liu, Muhua; Zhang, Dawei; Yang, Yan; Chen, Xuesi



Synthesis and optimization of a novel polymeric micelle based on hyaluronic acid and phospholipids for delivery of paclitaxel, in vitro and in-vivo evaluation.  


Novel polymeric micelles were synthesized based on hyaluronic acid (HA) and phospholipids (PEs) including 1,2-dimiristoyl phosphatidylethanolamine (DMPE) and 1,2-distearoyl phosphatidylethanolamine (DSPE). The newly developed micelles evaluated for the physicochemical properties including structural analysis by means of FTIR. Micelles were optimized for delivery of paclitaxel (PTX). The D-optimal design was applied in order to reach micelles with high entrapment efficiency (EE %) and minimum size, simultaneously. In this design the independent variables were the co-polymer type, the drug to polymer ratio and the formulation temperature, whereas the dependent variables were EE% and micelle size. The EE% of the optimized micelles was 46.8% and 59.9% for HA-DMPE and HA-DSPE micelles, respectively. The size of the optimized micelles was in the range of around 250nm. In vitro release study of the optimized micelles showed that PTX was released from HA-DMPE and HA-DSPE micelles as long as 23h and 34h, respectively. Differential scanning calorimetry (DSC) studies showed a conversion of the crystalline PTX molecules into the amorphous form in the micelles. In vivo real time image analysis showed that micellar system was mostly accumulated in the liver, spleen and heart. Accelerated stability studies represented that PTX loaded micelle formulations were stable both physically and chemically at least in 6 months' time. PMID:25148729

Saadat, Ebrahim; Amini, Mohsen; Khoshayand, Mohammad Reza; Dinarvand, Rassoul; Dorkoosh, Farid A



Feasibility studies of dermal delivery of paclitaxel with binary combinations of ethanol and isopropyl myristate: role of solubility, partitioning and lipid bilayer perturbation.  


In the current investigation, paclitaxel (PCL) delivery into the different layers of skin, vehicle optimization and relationship between vehicle composition and the relative contribution of solubility, partition and diffusion towards drug transport has been outlined. Saturation solubility of PCL was determined in ethanol (EtOH), isopropyl myristate (IPM) and their binary combinations, and partition studies performed to study the probability of skin depot formation. Epidermal and dermal partitioning was carried from PCL saturated vehicles. Skin permeation of PCL was studied using the rat skin. FT-IR has been utilized to study the skin barrier perturbation, and the localization of PCL and isopropyl myristate (IPM) in epidermis. High K(app) value in mineral oil/buffer indicated the tendency of PCL to form a reservoir in skin, and an inverse relationship between PCL solubility in different solvent systems and partitioning into epidermis was found. Maximum K(epidermis) for PCL was observed with IPM, while PCL in EtOH/IPM (1:1) showed high partitioning into dermis. Maximum flux of PCL was observed with EtOH/IPM (1:1). For lipophilic drug like PCL modulation of vehicle seems to be effective approach to increase the permeability across the skin. With a binary combination of EtOH/IPM (1:1) higher concentration of PCL can be delivered to deeper layer of skin whereas with IPM higher concentration of PCL could be localized in the epidermis. While engineering the delivery vehicle selection of solvents should be such that one of them is miscible in both hydrophilic and lipophilic phase like ethanol and another should be lipophilic in nature (IPM in this case) so that an optimum balance between 'push-pull' and 'blending' effect can be achieved. PMID:16126203

Panchagnula, Ramesh; Desu, Hariraghuram; Jain, Amit; Khandavilli, Sateesh



Nanostructured materials for selective recognition and targeted drug delivery  

NASA Astrophysics Data System (ADS)

Selective recognition requires the introduction of a molecular memory into a polymer matrix in order to make it capable of rebinding an analyte with a very high specificity. In addition, targeted drug delivery requires drug-loaded vesicles which preferentially localize to the sites of injury and avoid uptake into uninvolved tissues. The rapid evolution of nanotechnology is aiming to fulfill the goal of selective recognition and optimal drug delivery through the development of molecularly imprinted polymeric (MIP) nanoparticles, tailor-made for a diverse range of analytes (e.g., pharmaceuticals, pesticides, amino acids, etc.) and of nanostructured targeted drug carriers (e.g., liposomes and micelles) with increased circulation lifetimes. In the present study, PLGA microparticles containing multilamellar vesicles (MLVs), and MIP nanoparticles were synthesized to be employed as drug carriers and synthetic receptors respectively.

Kotrotsiou, O.; Kotti, K.; Dini, E.; Kammona, O.; Kiparissides, C.



Targeted Delivery of Multicomponent Cargos to Cancer via Nanoporous Particle-Supported Lipid Bilayers  

E-print Network

1 Targeted Delivery of Multicomponent Cargos to Cancer via Nanoporous Particle-Supported Lipid the SLB 24 5. Delivery of siRNA Cocktails via SP94-Targeted Protocells 25 Supplementary Figure 13 SP94 apoptosis of HCC within 24 hours 28 6. Delivery of Protein Toxins via SP94-Targeted Protocells 29

Brinker, C. Jeffrey


Multifunctional Inorganic Nanoparticles for Imaging, Targeting, and Drug Delivery  

PubMed Central

Drug delivery, magnetic resonance and fluorescence imaging, magnetic manipulation, and cell targeting are simultaneously possible using a multifunctional mesoporous silica nanoparticle. Superparamagnetic iron oxide nanocrystals were encapsulated inside mesostructured silica spheres that were labeled with fluorescent dye molecules and coated with hydrophilic groups to prevent aggregation. Water-insoluble anticancer drugs were delivered into human cancer cells; surface conjugation with cancer-specific targeting agents increased the uptake into cancer cells relative to that in non-cancerous fibroblasts. The highly versatile multifunctional nanoparticles could potentially be used for simultaneous imaging and therapeutic applications. PMID:19206485

Liong, Monty; Lu, Jie; Kovochich, Michael; Xia, Tian; Ruehm, Stefan G.; Nel, Andre E.; Tamanoi, Fuyuhiko; Zink, Jeffrey I.



PEG-Derivatized Embelin as a Nanomicellar Carrier For Delivery of Paclitaxel to Breast and Prostate Cancers  

PubMed Central

Paclitaxel (PTX) is one of the most effective chemotherapeutic agents for a wide spectrum of cancers, but its therapeutic benefit is often limited by severe side effects. We have developed a micelle-based PTX formulation based on a simple conjugate derived from polyethylene glycol 5000 (PEG5K) and embelin (EB). Embelin is a natural product and exhibits antitumor activity through blocking the activity of X-linked inhibitor of apoptosis protein (XIAP). PEG5K-EB2 conjugate self-assembles to form stable micelles in aqueous solution and efficiently encapsulates hydrophobic drugs such as PTX. PEG5K-EB2 micelles have a relatively low CMC of 0.002mg/mL (0.35?M) with sizes in the range of 20 ~ 30 nm with or without loaded PTX. In vitro cell uptake study showed that the PEG5K-EB2 micelles were efficiently taken up by tumor cells. In vitro release study showed that PTX formulated in PEG5K-EB2 micelles was slowly released over 5 days with much slower release kinetics than that of Taxol formulation. PTX formulated in PEG5K-EB2 micelles exhibited more potent cytotoxicity than Taxol in several cultured tumor cell lines. Total body near infrared fluorescence (NIRF) imaging showed that PEG5K-EB2 micelles were selectively accumulated at tumor site with minimal uptake in major organs including liver and spleen. PTX-loaded PEG5K-EB2 micelles demonstrated an excellent safety profile with a maximum tolerated dose (MTD) of 100–120 mg PTX/kg in mice, which was significantly higher than that for Taxol (15–20 mg PTX/kg). Finally, PTX formulated in PEG5K-EB2 micelles showed superior anti-tumor activity compared to Taxol in murine models of breast and prostate cancers. PMID:23182923

Lu, Jianqin; Huang, Yixian; Zhao, Wenchen; Marquez, Rebecca T.; Meng, Xiaojie; Li, Jiang; Gao, Xiang; Venkataramanan, Raman; Wang, Zhou; Li, Song



In vivo targeted delivery of nanoparticles for theranosis.  


Therapy and diagnosis are two major categories in the clinical treatment of disease. Recently, the word "theranosis" has been created, combining the words to describe the implementation of these two distinct pursuits simultaneously. For successful theranosis, the efficient delivery of imaging agents and drugs is critical to provide sufficient imaging signal or drug concentration in the targeted disease site. To achieve this purpose, biomedical researchers have developed various nanoparticles composed of organic or inorganic materials. However, the targeted delivery of these nanoparticles in animal models and patients remains a difficult hurdle for many researchers, even if they show useful properties in cell culture condition. In this Account, we review our strategies for developing theranostic nanoparticles to accomplish in vivo targeted delivery of imaging agents and drugs. By applying these rational strategies, we achieved fine multimodal imaging and successful therapy. Our first strategy involves physicochemical optimization of nanoparticles for long circulation and an enhanced permeation and retention (EPR) effect. We accomplished this result by testing various materials in mouse models and optimizing the physical properties of the materials with imaging techniques. Through these experiments, we developed a glycol chitosan nanoparticle (CNP), which is suitable for angiogenic diseases, such as cancers, even without an additional targeting moiety. The in vivo mechanism of this particle was examined through rationally designed experiments. In addition, we evaluated and compared the biodistribution and target-site accumulation of bare and drug-loaded nanoparticles. We then focus on the targeting moieties that bind to cell surface receptors. Small peptides were selected as targeting moieties because of their stability, low cost, size, and activity per unit mass. Through phage display screening, the interleukin-4 receptor binding peptide was discovered, and we combined it with our nanoparticles. This product accumulated efficiently in atherosclerotic regions or tumors during both imaging and therapy. We also developed hyaluronic acid nanoparticles that can bind efficiently to the CD44 antigen receptors abundant in many tumor cells. Their delivery mechanism is based on both physicochemical optimization for the EPR effect and receptor-mediated endocytosis by their hyaluronic acid backbone. Finally, we introduce the stimuli-responsive system related to the chemical and biological changes in the target disease site. Considering the relatively low pH in tumors and ischemic sites, we applied pH-sensitive micelle to optical imaging, magnetic resonance imaging, anticancer drug delivery, and photodynamic therapy. In addition, we successfully evaluated the in vivo imaging of enzyme activity at the target site with an enzyme-specific peptide sequence and CNPs. On the basis of these strategies, we were able to develop self-assembled nanoparticles for in vivo targeted delivery, and successful results were obtained with them in animal models for both imaging and therapy. We anticipate that these rational strategies, as well as our nanoparticles, will be applied in both the diagnosis and therapy of many human diseases. These theranostic nanoparticles are expected to greatly contribute to optimized therapy for individual patients as personalized medicine, in the near future. PMID:21851104

Koo, Heebeom; Huh, Myung Sook; Sun, In-Cheol; Yuk, Soon Hong; Choi, Kuiwon; Kim, Kwangmeyung; Kwon, Ick Chan



Multiscale Modeling of Functionalized Nanocarriers in Targeted Drug Delivery  

PubMed Central

Targeted drug delivery using functionalized nanocarriers (NCs) is a strategy in therapeutic and diagnostic applications. In this paper we review the recent development of models at multiple length and time scales and their applications to targeting of antibody functionalized nanocarriers to antigens (receptors) on the endothelial cell (EC) surface. Our mesoscale (100 nm-1 ?m) model is based on phenomenological interaction potentials for receptor-ligand interactions, receptor-flexure and resistance offered by glycocalyx. All free parameters are either directly determined from independent biophysical and cell biology experiments or estimated using molecular dynamics simulations. We employ a Metropolis Monte Carlo (MC) strategy in conjunction with the weighted histogram analysis method (WHAM) to compute the free energy landscape (potential of mean force or PMF) associated with the multivalent antigen-antibody interactions mediating the NC binding to EC. The binding affinities (association constants) are then derived from the PMF by computing absolute binding free energy of binding of NC to EC, taking into account the relevant translational and rotational entropy losses of NC and the receptors. We validate our model predictions by comparing the computed binding affinities and PMF to a wide range of experimental measurements, including in vitro cell culture, in vivo endothelial targeting, atomic force microscopy (AFM), and flow chamber experiments. The model predictions agree closely and quantitatively with all types experimental measurements. On this basis, we conclude that our computational protocol represents a quantitative and predictive approach for model driven design and optimization of functionalized NCs in targeted vascular drug delivery. PMID:22116782

Liu, Jin; Bradley, Ryan; Eckmann, David M.; Ayyaswamy, Portonovo S.; Radhakrishnan, Ravi



Chlorotoxin Labeled Magnetic Nanovectors for Targeted Gene Delivery to Glioma  

PubMed Central

Glioma accounts for 80% of brain tumors, and currently remains one of the most lethal forms of cancers. Gene therapy could potentially improve the dismal prognosis of patients with glioma, but this treatment modality has not yet reached the bedside from the laboratory due to the lack of safe and effective gene delivery vehicles. In this study we investigate targeted gene delivery to C6 glioma cells in a xenograft mouse model using chlorotoxin (CTX) labeled nanoparticles. The developed nanovector consists of an iron oxide nanoparticle core, coated with a copolymer of chitosan, polyethylene glycol (PEG) and polyethylenimine (PEI). Green fluorescent protein (GFP) encoding DNA was bound to these nanoparticles, and CTX was then attached using a short PEG linker. Nanoparticles without CTX were also prepared as a control. Mice bearing C6 xenograft tumors were injected intravenously with the DNA bound nanoparticles. Nanoparticle accumulation in the tumor site was monitored using magnetic resonance imaging and analyzed by histology, and GFP gene expression was monitored through Xenogen IVIS fluorescence imaging and confocal fluorescence microscopy. Interestingly, the CTX did not affect the accumulation of nanoparticles at the tumor site, but specifically enhanced their uptake into cancer cells as evidenced by higher gene expression. These results indicate that this targeted gene delivery system may potentially improve treatment outcome of gene therapy for glioma and other deadly cancers. PMID:20731441

Kievit, Forrest M.; Veiseh, Omid; Fang, Chen; Bhattarai, Narayan; Lee, Donghoon; Ellenbogen, Richard G.; Zhang, Miqin



Ultrasound-Mediated Destruction of LHRHa Targeted and Paclitaxel Loaded Lipid Microbubbles Induces Proliferation Inhibition and Apoptosis in Ovarian Cancer Cells  

PubMed Central

Although paclitaxel (PTX) is used with platinum as the first line chemotherapy regimen for ovarian cancer, its clinical efficacy is often limited by severe adverse effects. Ultrasound targeted microbubble destruction (UTMD) technique holds a great promise in minimizing the side effects and maximizing the therapeutic efficacy. However, the technique typically uses non-targeted microbubbles with suboptimal efficiency. We synthesized targeted and PTX-loaded microbubbles (MBs) for UTMD mediated chemotherapy in ovarian cancer cells. PTX-loaded lipid MBs were coated with a luteinizing hormone-releasing hormone analogue (LHRHa) through a biotin-avidin linkage to target the ovarian cancer A2780/DDP cells that express the LHRH receptor. In the cell culture studies, PTX-loaded and LHRHa targeted MBs (TPLMBs) in combination with ultrasound (300 kHz, 0.5 W/cm2, 30 seconds) demonstrated anti-proliferative activities of 41.30 ± 3.93%, 67.76 ± 2.45%, and 75.93 ± 2.81% at 24 hours, 48 hours, and 72 hours after the treatment, respectively. The cell apoptosis ratio at 24 hours after the treatment is 32.6 ± 0.79 %, which is significantly higher than other treatment groups such as PTX only and no-targeted PTX-loaded MBs (NPLMBs) with or without ultrasound mediation. Our experiment verifies the hypothesis that ultrasound mediation of ovarian cancer targeted and drug loaded MBs will enhance the PTX therapeutic efficiency. PMID:24266423

Liu, Hongxia; Chang, Shufang; Sun, Jiangchuan; Zhu, Shenyin; Pu, Caixiu; Zhu, Yi; Wang, Zhigang; Xu, Ronald X.



Micelles of Different Morphologies—Advantages of Worm-like Filomicelles of PEO-PCL in Paclitaxel Delivery  

Microsoft Academic Search

Purpose  Worm-like and spherical micelles are both prepared here from the same amphiphilic diblock copolymer, poly(ethylene oxide)-b-poly (?-caprolactone) (PEO [5 kDa]–PCL [6.5 kDa]) in order to compare loading and delivery of hydrophobic drugs.\\u000a \\u000a \\u000a \\u000a Materials and Methods  Worm-like micelles of this degradable copolymer are nanometers in cross-section and spontaneously assemble to stable lengths\\u000a of microns, resembling filoviruses in some respects and thus suggesting

Shenshen Cai; Kandaswamy Vijayan; Debbie Cheng; Eliana M. Lima; Dennis E. Discher



Integrated nanoplasmonic-nanofluidic biosensors with targeted delivery of analytes  

NASA Astrophysics Data System (ADS)

Performances of the biosensors are often limited by the depletion zones created around the sensing area which impede the effective analyte transport. To overcome this limitation, we propose and demonstrate a nanoplasmonic-nanofluidic sensor enabling targeted delivery of analytes to the sensor surface with dramatic improvements in mass transport efficiency. Our sensing platform is based on extraordinary light transmission effect in suspended plasmonic nanoholes. This scheme allows three-dimensional control of the fluidic flow by connecting separate layers of microfluidic channels through plasmonic/nanofluidic holes. To implement the proposed sensor platform, we also introduce a lift-off free nanofabrication method.

Yanik, Ahmet Ali; Huang, Min; Artar, Alp; Chang, Tsung-Yao; Altug, Hatice



A genome-wide RNAi screen identifies novel targets of neratinib sensitivity leading to neratinib and paclitaxel combination drug treatments.  


ErbB2 is frequently activated in tumors, and influences a wide array of cellular functions, including proliferation, apoptosis, cell motility and adhesion. HKI-272 (neratinib) is a small molecule pan-kinase inhibitor of the ErbB family of receptor tyrosine kinases, and shows strong antiproliferative activity in ErbB2-overexpressing breast cancer cells. We undertook a genome-wide pooled lentiviral RNAi screen to identify synthetic lethal or enhancer (synthetic modulator screen) genes that interact with neratinib in a human breast cancer cell line (SKBR-3). These genes upon knockdown would modulate cell viability in the presence of subeffective concentrations of neratinib. We discovered a diverse set of genes whose depletion selectively impaired or enhanced the viability of SKBR-3 cells in the presence of neratinib. We observed diverse pathways including EGFR, hypoxia, cAMP, and protein ubiquitination that, when co-treated with RNAi and neratinib, resulted in arrest of cell proliferation. Examining the changes of these genes and their protein products also led to a rationale for clinically relevant drug combination treatments. Treatment of cells with either paclitaxel or cytarabine in combination with neratinib resulted in a strong antiproliferative effect. The identification of novel mediators of cellular response to neratinib and the development of potential drug combination treatments have expanded our understanding of neratinib's mode-of-action for the development of more effective therapeutic regimens. Notably, our findings support a paclitaxel and neratinib phase III clinical trial in breast cancer patients. PMID:21487605

Seyhan, Attila A; Varadarajan, Usha; Choe, Sung; Liu, Yan; McGraw, John; Woods, Matthew; Murray, Stuart; Eckert, Amy; Liu, Wei; Ryan, Terence E



Synergistic Antitumor Activity from Two-Stage Delivery of Targeted Toxins and Endosome-Disrupting Nanoparticles  

E-print Network

Plant-derived Type I toxins are candidate anticancer therapeutics requiring cytosolic delivery into tumor cells. We tested a concept for two-stage delivery, whereby tumor cells precoated with an antibody-targeted gelonin ...

Su, Xingfang


Polyelectrolyte Nanogels Decorated with Monoclonal Antibody for Targeted Drug Delivery  

PubMed Central

Novel surface-functionalized cross-linked nanogels were developed as a platform to allow conjugation of monoclonal antibodies (mAb) for targeted drug delivery. Well-defined diblock copolymers of poly(ethylene glycol)-b-poly(methacrylic acid) (PEG-b-PMA) with PEG terminal aldehyde functionality were synthesized by atom transfer radical polymerization (ATRP) and characterized by GPC and 1H NMR. These copolymers were used to prepare nanogels via condensation of PEG-b-PMA with Ca2+ ions into micelle-like aggregates, cross-linking of the PMA/Ca2+ cores and removal of Ca2+ ions. The resulting nanogels represent highly swollen spherical polyelectrolyte particles with free terminal aldehyde functionalities at the nonionic PEG chains. A reductive amination reaction between aldehyde groups and amino groups of mAb resulted in effective conjugation to the nanogels of mAb CC49 against tumor-associated glycoprotein 72 (TAG-72). The mAb retained the binding affinity to bovine submaxillary mucin after conjugation as shown by surface plasmon resonance (SPR). Therefore, aldehyde functionalized nanogels can be linked to mAb using a simple, one-step approach. They may have potential for targeted delivery of diagnostic and therapeutic agents to tumors. PMID:21503276

Nukolova, Nataliya V.; Yang, Zigang; Kim, Jong Oh; Kabanov, Alexander V.; Bronich, Tatiana K.



Amphoteric hyaluronic acid derivative for targeting gene delivery.  


The study aimed to develop an amphoteric hyaluronic acid (HA) derivative with polyethyleneimine (PEI) chains (HAP) for gene delivery to overcome the disadvantages of PEI as gene carrier including the cytotoxicity caused by excess of positive charge, non-special interaction and aggregation in the blood, and non-target gene delivery. The HAP was synthesized by an imine reaction between periodate-oxidized HA and PEI. The HAP/DNA complex was prepared, and its characterization was investigated. The size of complex with higher molecular weight HA in PBS was about 200 nm at optimal charge ratio. No apparent aggregation among the particles was observed. The HAPs also showed high protection of DNA from nuclease, better dissociation of DNA from the complex and lower cytotoxicity. It also exhibited higher transfection efficiency in HepG2 cells than the PEI/DNA complex. Among all complexes, the HAP50/DNA complex was especially found to be most efficient, yielding comparable transfection efficiency with that of Lipofectamine/DNA lipoplexes. Moreover, the HAP-IR820 obviously accumulated in tumor after i.v. administration as compared to the PEI-IR820, which indicated that the HAP could assist the DNA targeting to the tumor. Therefore, HAP should be a promising non-viral gene vector. PMID:20864163

Yao, Jing; Fan, Ying; Du, Ronghui; Zhou, Jianping; Lu, Yun; Wang, Wei; Ren, Jin; Sun, Xiaojing



Pharmaceutical approaches to colon targeted drug delivery systems  

Microsoft Academic Search

Purpose. Although oral delivery has become a widely accepted route of administration of therapeutic drugs, the gastrointestinal tract presents several formidable barriers to drug delivery. Colonic drug delivery has gained increased importance not just for the delivery of the drugs for the treatment of local diseases associated with the colon but also for its potential for the delivery of proteins

M. K. Chourasia; S. K. Jain


Potential of magnetic nanoparticles for targeted drug delivery  

PubMed Central

Nanoparticles (NPs) play an important role in the molecular diagnosis, treatment, and monitoring of therapeutic outcomes in various diseases. Their nanoscale size, large surface area, unique capabilities, and negligible side effects make NPs highly effective for biomedical applications such as cancer therapy, thrombolysis, and molecular imaging. In particular, nontoxic superparamagnetic magnetic NPs (MNPs) with functionalized surface coatings can conjugate chemotherapeutic drugs or be used to target ligands/proteins, making them useful for drug delivery, targeted therapy, magnetic resonance imaging, transfection, and cell/protein/DNA separation. To optimize the therapeutic efficacy of MNPs for a specific application, three issues must be addressed. First, the efficacy of magnetic targeting/guidance is dependent on particle magnetization, which can be controlled by adjusting the reaction conditions during synthesis. Second, the tendency of MNPs to aggregate limits their therapeutic use in vivo; surface modifications to produce high positive or negative charges can reduce this tendency. Finally, the surface of MNPs can be coated with drugs which can be rapidly released after injection, resulting in targeting of low doses of the drug. Drugs therefore need to be conjugated to MNPs such that their release is delayed and their thermal stability enhanced. This chapter describes the creation of nanocarriers with a high drug-loading capacity comprised of a high-magnetization MNP core and a shell of aqueous, stable, conducting polyaniline derivatives and their applications in cancer therapy. It further summarizes some newly developed methods to synthesize and modify the surfaces of MNPs and their biomedical applications. PMID:24198498

Yang, Hung-Wei; Hua, Mu-Yi; Liu, Hao-Li; Huang, Chiung-Yin; Wei, Kuo-Chen



Potential of magnetic nanoparticles for targeted drug delivery.  


Nanoparticles (NPs) play an important role in the molecular diagnosis, treatment, and monitoring of therapeutic outcomes in various diseases. Their nanoscale size, large surface area, unique capabilities, and negligible side effects make NPs highly effective for biomedical applications such as cancer therapy, thrombolysis, and molecular imaging. In particular, nontoxic superparamagnetic magnetic NPs (MNPs) with functionalized surface coatings can conjugate chemotherapeutic drugs or be used to target ligands/proteins, making them useful for drug delivery, targeted therapy, magnetic resonance imaging, transfection, and cell/protein/DNA separation. To optimize the therapeutic efficacy of MNPs for a specific application, three issues must be addressed. First, the efficacy of magnetic targeting/guidance is dependent on particle magnetization, which can be controlled by adjusting the reaction conditions during synthesis. Second, the tendency of MNPs to aggregate limits their therapeutic use in vivo; surface modifications to produce high positive or negative charges can reduce this tendency. Finally, the surface of MNPs can be coated with drugs which can be rapidly released after injection, resulting in targeting of low doses of the drug. Drugs therefore need to be conjugated to MNPs such that their release is delayed and their thermal stability enhanced. This chapter describes the creation of nanocarriers with a high drug-loading capacity comprised of a high-magnetization MNP core and a shell of aqueous, stable, conducting polyaniline derivatives and their applications in cancer therapy. It further summarizes some newly developed methods to synthesize and modify the surfaces of MNPs and their biomedical applications. PMID:24198498

Yang, Hung-Wei; Hua, Mu-Yi; Liu, Hao-Li; Huang, Chiung-Yin; Wei, Kuo-Chen



Advancements in the understanding of Paclitaxel metabolism in tissue culture.  


Paclitaxel is a potent chemotherapeutic agent approved in the treatment of a variety of cancers, and under evaluation for the treatment of Alzheimer's and heart disease. Originally isolated from Taxus brevifolia, this highly substituted ring diterpenoid belongs to a family of plant secondary metabolites known as taxoids. Paclitaxel is currently supplied through both a semi-synthetic process and plant cell culture. Taxus spp. cell culture offers the potential to produce large amounts of paclitaxel and related taxoids, although variability in accumulation and low yields represent key limitations. Thus, intense efforts have been put forth towards understanding Taxus spp. metabolism to increase paclitaxel accumulation in cell culture. While elicitation and environmental optimization have provided some success in increasing paclitaxel accumulation in vitro, understanding metabolism of paclitaxel on the molecular level is essential for process optimization. Utilizing direct and indirect molecular techniques, a further understanding of paclitaxel biosynthesis has been gained, though knowledge into other aspects of paclitaxel global metabolism, such as regulation, transport, and degradation is lacking. Taxus spp. cell cultures are highly heterogeneous, displaying significant cell-cell variability in growth and paclitaxel accumulation. Information gathered on culture subpopulations as well as putative transcriptional bottlenecks in paclitaxel biosynthesis, coupled with successful transformation of Taxus spp. will allow for the targeted metabolic engineering of Taxus spp. or other model organisms for paclitaxel accumulation to ensure future supply of this important pharmaceutical. PMID:17691991

Vongpaseuth, Kham; Roberts, Susan C



Targeted drug delivery and enhanced intracellular release using functionalized liposomes  

NASA Astrophysics Data System (ADS)

The ability to target cancer cells using an appropriate drug delivery system can significantly reduce the associated side effects from cancer therapies and can help in improving the overall quality of life, post cancer survival. Integrin alpha5beta1 is expressed on several types of cancer cells, including colon cancer and plays an important role in tumor growth and metastasis. Thus, the ability to target the integrin alpha 5beta1 using an appropriate drug delivery nano-vector can significantly help in inhibiting tumor growth and reducing tumor metastasis. The work in this thesis focuses on designing and optimizing, functionalized stealth liposomes (liposomes covered with polyethylene glycol (PEG)) that specifically target the integrin alpha5beta1. The PEG provides a steric barrier allowing the liposomes to circulate in the blood for longer duration and the functionalizing moiety, PR_b peptide specifically recognizes and binds to integrin alpha5beta1 expressing cells. The work demonstrates that by optimizing the amount of PEG and PR_b on the liposomal interface, nano-vectors can be engineered that bind to CT26.WT colon cancer cells in a specific manner and internalize through alpha 5beta1-mediated endocytosis. To further improve the efficacy of the system, PR_b functionalized pH-sensitive stealth liposomes that exhibit triggered release under mild acidic conditions present in endocytotic vesicles were designed. The study showed that PR_b functionalized pH-sensitive stealth liposomes, undergo destabilization under mildly acidic conditions and incorporation of the PR_b peptide does not significantly affect the pH-sensitivity of the liposomes. PR_b functionalized pH-sensitive stealth liposomes bind to CT26.WT colon carcinoma cells that express integrin alpha5beta 1, undergo cellular internalization, and release their load intracellularly in a short period of time as compared to other formulations. PR_b-targeted pH-sensitive stealth liposomes encapsulating 5-fluorouracil (5-FU) show significantly higher cytotoxicity than the PR_b-targeted inert stealth liposomes and the non-targeted stealth liposomes (both pH-sensitive and inert). The studies demonstrated that optimized PR_b functionalized pH sensitive liposomes have the potential to deliver a payload, such as chemotherapeutic agents, directly to colon cancer cells in an efficient and specific manner.

Garg, Ashish


Paclitaxel is incorporated by mesenchymal stromal cells and released in exosomes that inhibit in vitro tumor growth: a new approach for drug delivery.  


Mesenchymal stromal cells (MSCs) have been proposed for delivering anticancer agents because of their ability to home in on tumor microenvironment. We found that MSCs can acquire strong anti-tumor activity after priming with Paclitaxel (PTX) through their capacity to uptake and then release the drug. Because MSCs secrete a high amount of membrane microvesicles (MVs), we here investigated the role of MVs in the releasing mechanism of PTX. The murine SR4987 line was used as MSC model. The release of PTX from SR4987 in the conditioned medium (CM) was checked by HPLC and the anti-tumor activity of both CM and MVs was tested on the human pancreatic cell line CFPAC-1. MVs were isolated by ultracentrifugation, analyzed by transmission (TEM) and scanning electron microscopy (SEM), and the presence of PTX by the Fourier transformed infrared (FTIR) microspectroscopy. SR4987 loaded with PTX (SR4987PTX) secreted a significant amount of PTX and their CM possessed strong anti-proliferative activity on CFPAC-1. At TEM and SEM, SR4987PTX showed an increased number of "vacuole-like" structures and shed a relevant number of MVs, but did not differ from untreated SR4987. However, SR4987PTX-derived-MVs (SR4987PTX-MVs) demonstrated a strong anti proliferative activity on CFPAC-1. FTIR analysis of SR4987PTX-MVs showed the presence of an absorption spectrum in the corresponding regions of the PTX marker, absent in MVs from SR4987. Our work is the first demonstration that MSCs are able to package and deliver active drugs through their MVs, suggesting the possibility of using MSCs as a factory to develop drugs with a higher cell-target specificity. PMID:25084218

Pascucci, Luisa; Coccè, Valentina; Bonomi, Arianna; Ami, Diletta; Ceccarelli, Piero; Ciusani, Emilio; Viganò, Lucia; Locatelli, Alberta; Sisto, Francesca; Doglia, Silvia Maria; Parati, Eugenio; Bernardo, Maria Ester; Muraca, Maurizio; Alessandri, Giulio; Bondiolotti, Gianpietro; Pessina, Augusto



Annexin A5 Molecular Imaging Targeted Drug Delivery  

E-print Network

Ó The Author(s) 2010. This article is published with open access at Abstract Cells are able to execute apoptosis by activating series of specific biochemical reactions. One of the most prominent characteristics of cell death is the externalization of phosphatidylserine (PS), which in healthy cells resides predominantly in the inner leaflet of the plasma membrane. These features have made PS-externalization a well-explored phenomenon to image cell death for diagnostic purposes. In addition, it was demonstrated that under certain conditions viable cells express PS at their surface such as endothelial cells of tumor blood vessels, stressed tumor cells and hypoxic cardiomyocytes. Hence, PS has become a potential target for therapeutic strategies aiming at Targeted Drug Delivery. In this review we highlight the biomarker PS and various PS-binding compounds that have been employed to target PS for diagnostic purposes. We emphasize the 35 kD human protein annexin A5, that has been developed as a Molecular Imaging agent to measure cell death in vitro, and non-invasively in vivo in animal models and in patients with cardiovascular diseases and cancer. Recently focus has shifted from diagnostic towards therapeutic applications employing annexin A5 in strategies to deliver drugs to cells that express PS at their surface.

Kristof Schutters; Chris Reutelingsperger; K. Schutters; C. Reutelingsperger; C. Reutelingsperger



Cubosomes as targeted drug delivery systems - a biopharmaceutical approach.  


Cubosomes are reversed bicontinuous cubic phases and possess unique physicochemical properties. These special systems are receiving much attention for the delivery of various hydrophilic, hydrophobic and amphiphilic drugs with enhanced bioavailability and high loading capacity. A wide variety of drugs are applicable for cubosome formulation for various routes of delivery. The lipids used in cubosome formulation are more stable and offer stability to the formulation during shelf-life. The article reviews about the back ground, techniques of cubosome preparation such as high pressure homogenization, probe ultrasonication and automated cubosome preparation; and also methods of cubosomes preparation such as top down, bottom up and other methods with pictorial presentation. This article emphasizes the phase transition and also targeted approaches of cubosomes. The characterization studies for cubosomes such as cryo transmission electron microscopy, differential scanning calorimetry and scanning electron microscopy followed by in-vitro and in-vivo evaluation studies of cubosomes were explained with appropriate examples. Recent applications of cubosomes were explained with reference to flurbiprofen, odorranalectin, diazepam and dexamethasone. The advantages, disadvantages and limitations of cubosomal technology were emphasized. PMID:24836404

Lakshmi, Naga M; Yalavarthi, Prasanna R; Vadlamudi, Harini C; Thanniru, Jyotsna; Yaga, Gowri; K, Haritha



PECAM-targeted delivery of SOD inhibits endothelial inflammatory response  

PubMed Central

Elevated generation of reactive oxygen species (ROS) by endothelial enzymes, including NADPH-oxidase, is implicated in vascular oxidative stress and endothelial proinflammatory activation involving exposure of vascular cell adhesion molecule-1 (VCAM-1). Catalase and superoxide dismutase (SOD) conjugated with antibodies to platelet/endothelial cell adhesion molecule 1 (PECAM-1) bind specifically to endothelium and inhibit effects of corresponding ROS, H2O2, and superoxide anion. In this study, anti-PECAM/SOD, but not anti-PECAM/catalase or nontargeted enzymes, including polyethylene glycol (PEG)-SOD, inhibited 2- to 3-fold VCAM expression caused by tumor necrosis factor (TNF), interleukin-1?, and lipopolysaccharide. Anti- PECAM/SOD, but not nontargeted counterparts, accumulated in vascular endothelium after intravenous injection, localized in endothelial endosomes, and inhibited by 70% lipopolysaccharide-caused VCAM-1 expression in mice. Anti-PECAM/SOD colocalized with EEA-1-positive endothelial vesicles and quenched ROS produced in response to TNF. Inhibitors of NADPH oxidase and anion channel ClC3 blocked TNF-induced VCAM expression, affirming that superoxide produced and transported by these proteins, respectively, mediates inflammatory signaling. Anti-PECAM/SOD abolished VCAM expression caused by poly(I:C)-induced activation of toll-like receptor 3 localized in intracellular vesicles. These results directly implicate endosomal influx of superoxide in endothelial inflammatory response and suggest that site-specific interception of this signal attained by targeted delivery of anti-PECAM/SOD into endothelial endosomes may have anti-inflammatory effects.—Shuvaev, V. V., Han, J., Yu, K. J., Huang, S., Hawkins, B. J., Madesh, M., Nakada, M., and Muzykantov, V. R. PECAM-targeted delivery of SOD inhibits endothelial inflammatory response. PMID:20876216

Shuvaev, Vladimir V.; Han, Jingyan; Yu, Kevin J.; Huang, Shaohui; Hawkins, Brian J.; Madesh, Muniswamy; Nakada, Marian; Muzykantov, Vladimir R.



Synthetic Aptamer-Polymer Hybrid Constructs for Programmed Drug Delivery into Specific Target Cells  

E-print Network

Synthetic Aptamer-Polymer Hybrid Constructs for Programmed Drug Delivery into Specific Target Cells effective drug delivery with fewer side effects.8,9 The systems that have made the greatest progress. They achieve this by performing a coordinated series of complex functions, resulting in delivery that is far

Akhmedov, Azer


Magnetically responsive microparticles for targeted drug and radionuclide delivery.  

SciTech Connect

We are currently investigating the use of magnetic particles--polymeric-based spheres containing dispersed magnetic nanocrystalline phases--for the precise delivery of drugs via the human vasculature. According to this review, meticulously prepared magnetic drug targeting holds promise as a safe and effective method of delivering drugs to specific organ, tissue or cellular targets. We have critically examined the wide range of approaches in the design and implementation of magnetic-particle-based drug delivery systems to date, including magnetic particle preparation, drug encapsulation, biostability, biocompatibility, toxicity, magnetic field designs, and clinical trials. However, we strongly believe that there are several limitations with past developments that need to be addressed to enable significant strides in the field. First, particle size has to be carefully chosen. Micrometer-sized magnetic particles are better attracted over a distance than nanometer sized magnetic particles by a constant magnetic field gradient, and particle sizes up to 1 {micro}m show a much better accumulation with no apparent side effects in small animal models, since the smallest blood vessels have an inner diameter of 5-7 {micro}m. Nanometer-sized particles <70 nm will accumulate in organ fenestrations despite an effective surface stabilizer. To be suitable for future human applications, our experimental approach synthesizes the magnetic drug carrier according to specific predefined outcome metrics: monodisperse population in a size range of 100 nm to 1.0 {micro}m, non-toxic, with appropriate magnetic properties, and demonstrating successful in vitro and in vivo tests. Another important variable offering possible improvement is surface polarity, which is expected to prolong particle half-life in circulation and modify biodistribution and stability of drugs in the body. The molecules in the blood that are responsible for enhancing the uptake of particles by the reticuloendothelial system (RES) prefer to associate with hydrophobic surfaces. Accordingly, we will tackle this challenge by modifying the particles with hydrophilic coatings such as PEG or poloxamer (co-polymers containing hydrophobic polyoxypropylene segments and repetitive polyoxyethylene hydrophilic groups), which have a proven ability to mask recognition by the RES. Modeling is needed to help optimize the performance of targeted magnetic-particle delivery, enhance its medicinal value, and expedite its medical application. To this end, scientists at Argonne National Laboratory, working with The University of Chicago and Cleveland Clinic Hospital, are working on an effective magnetic drug targeting system based on custom magnetic field designs coupled to a three-dimensional imaging platform that addresses all associated physical and theoretical problems. Furthermore, while our clinical trial results are encouraging with regard to the tolerance and applicability of the system, more improvements must be made with respect to future study designs and systems being used. Given the technical hurdles in developing this potentially important technology, we believe we have made great progress and that we have a strong developmental plan.

Kaminski, M. D.; Ghebremeskel, A. N.; Nunez, L.; Kasza, K. E.; Chang, F.; Chien, T.-H.; Fisher, P. F.; Eastman, J. A.; Rosengart, A. J.; McDonald, L.; Xie, Y.; Johns, L.; Pytel, P.; Hafeli, U. O.



Role of nanotechnology in targeted drug delivery and imaging: a concise review  

Microsoft Academic Search

The use of nanotechnology in drug delivery and imaging in vivo is a rapidly expanding field. The emphases of this review are on biophysical attributes of the drug delivery and imaging platforms as well as the biological aspects that enable targeting of these platforms to injured and diseased tissues and cells. The principles of passive and active targeting of nanosized

Otilia M. Koo; Israel Rubinstein; Hayat Onyuksel



Electrospun Nanofibers of Guar Galactomannan for Targeted Drug Delivery  

NASA Astrophysics Data System (ADS)

Guar galactomannan is a biodegradable polysaccharide used widely in the food industry but also in the cosmetics, pharmaceutical, oil drilling, textile and paper industries. Guar consists of a mannose backbone and galactose side groups that are both susceptible to enzyme degradation, a unique property that can be explored for targeted drug delivery especially since those enzymes are naturally secreted by the microflora in human colon. The present study can be divided into three parts. In the first part, we discuss ways to modify guar to produce nanofibers by electrospinning, a process that involves the application of an electric field to a polymer solution or melt to facilitate production of fibers in the sub-micron range. Nanofibers are currently being explored as the next generation of drug carriers due to its many advantages, none more important than the fact that nanofibers are on a size scale that is a fraction of a hair's width and have large surface-to-volume ratio. The incorporation and controlled release of nano-sized drugs is one way in which nanofibers are being utilized in drug delivery. In the second part of the study, we explore various methods to crosslink guar nanofibers as a means to promote water-resistance in a potential drug carrier. The scope and utility of water-resistant guar nanofibers can only be fully appreciated when subsequent drug release studies are carried out. To that end, the third part of our study focuses on understanding the kinetics and diffusion mechanisms of a model drug, Rhodamine B, through moderately-swelling (crosslinked) hydrogel nanofibers in comparison to rapidly-swelling (non-crosslinked) nanofibers. Along the way, our investigations led us to a novel electrospinning set-up that has a unique collector designed to capture aligned nanofibers. These aligned nanofiber bundles can then be twisted to hold them together like yarn. From a practical standpoint, these yarns are advantageous because they come freely suspended and without any attached support. As composites of aligned nanofibers, yarns potentially combine the inherent advantages of nanofibers with the strength and pliability of larger sized fibers. As such, we became interested in exploring the potential of nanofiber yarns as drug carriers. Our study evolved to accommodate comparative studies between the behavior of traditional nonwoven mats and nanofiber yarns. Throughout the process, we sought to answer the bigger question: Can guar galactomannan nanofibers be used as a new biodegradable platform for drug delivery?

Chu, Hsiao Mei Annie



Buparvaquone loaded solid lipid nanoparticles for targeted delivery in theleriosis  

PubMed Central

Background: Buparvaquone (BPQ), a hydroxynaphthoquinone derivative, has been investigated for the treatment of many infections and is recommended as the gold standard for the treatment of theileriosis. Theileriosis, an intramacrophage infection is localized mainly in reticuloendotheileial system (RES) organs. The present study investigates development of solid lipid nanoparticles (SLN) of BPQ for targeted delivery to the RES. Materials and Methods: BPQ SLN was prepared using melt method by adding a molten mixture into aqueous Lutrol F68 solution (80°C). Larger batches were prepared up to 6 g of BPQ with GMS: BPQ, 2:1. SLN of designed size were obtained using ultraturrax and high pressure homogenizer. A freeze and thaw study was used to optimize type and concentration of cryoprotectant with Sf: Mean particle size, Si: Initial particle size <1.3. Differential scanning calorimetry (DSC), powder X-ray diffraction (XRD) and scanning electron microscope (SEM) study was performed on optimized formulation. Formulation was investigated for in vitro serum stability, hemolysis and cell uptake study. Pharmacokinetic and biodistribution study was performed in Holtzman rat. Results: Based on solubility in lipid; glyceryl monostearate (GMS) was selected for preparation of BPQ SLN. Batches of BPQ SLN were optimized for average particle size and entrapment efficiency at <100 mg solid content. A combination of Solutol HS-15 and Lutrol F68 at 2% w/v and greater enabled the desired Sf/Si < 1.3. Differential scanning calorimetry and powder X-ray diffraction revealed decrease in crystallinity of BPQ in BPQ SLN while, scanning electron microscope revealed spherical morphology. BPQ SLN revealed good stability at 4°C and 25°C. Low hemolytic potential (<8%) and in vitro serum stability up to 5 h was observed. Cytotoxicity of SLN to the U937 cell was low. The macrophage cell line revealed high (52%) uptake of BPQ SLN in 1 h suggesting the potential to RES uptake. SLN revealed longer circulation and biodistrbution study confirmed high RES uptake (75%) in RES organs like liver lung spleen etc. Conclusion: The high RES uptake suggests BPQ SLN as a promising approach for targeted and improved delivery in theileriosis. PMID:24459400

Soni, Maheshkumar P.; Shelkar, Nilakash; Gaikwad, Rajiv V.; Vanage, Geeta R.; Samad, Abdul; Devarajan, Padma V.



Development of novel drug delivery prototypes devices for targeted delivery drug therapy at the molecular level in aqueous media.  


A novel approach in target specific molecular prototype drug delivery system concerns the attempt to employ radical affording substances (RAS) or radical quenching substances (RQS) as prodrugs able to produce irreversible damage on the desired target and therefore to stimulate cellular apoptosis. However, radical species generated can react quickly within the chemical environment prior to reaching its proper site of action. In this short communication, we report our investigations towards developing two alternative novel, simple, flexible and effective drug delivery systems that provide optimal dosage of drugs precisely where and when needed and therefore achieve and sustain a complex delivery profile. We have demonstrated the application of two effective molecular prototype delivery systems able to harness free radical reactivity within the laboratory where biological processes can be studied and controlled, leading to the prevention of disease and the development of new treatments for disease states mediated by free radicals. PMID:21843149

George, Roy; Oberhozer, Theunis Gerhardus; Perchyonok, Victoria Tamara



Dose-dense Paclitaxel in Advanced Ovarian Cancer.  


Carboplatin and paclitaxel, delivered on a 3-weekly basis, is the historical standard for the management of advanced epithelial ovarian cancers (EOC). Increased dose intensity, the inclusion of additional active cytotoxic agents and lengthening treatment duration have failed to improve the outcomes seen with standard doses of carboplatin and paclitaxel in the treatment of EOC. Dose-dense (i.e. weekly) delivery of paclitaxel may exploit anticancer mechanisms such as anti-angiogenesis and the induction of apoptosis. Tumour regrowth may be more effectively impaired by the dose-dense delivery of paclitaxel. Non-randomised studies of dose-dense chemotherapy in EOC have been promising, particularly in heavily pretreated and platinum-resistant disease, with reported response rates as high as 60%. Dose-dense paclitaxel also seems to be well tolerated. These observations led to a number of comparative trials of dose-dense paclitaxel chemotherapy, three have been reported and four are ongoing. This review explores the rationale behind dose-dense delivery of paclitaxel and evaluates the results of completed phase III trials. PMID:25455846

Kumar, A; Hoskins, P J; Tinker, A V



Transporter targeted gatifloxacin prodrugs: Synthesis, permeability, and topical ocular delivery  

PubMed Central

Purpose To design and synthesize prodrugs of gatifloxacin targeting OCT, MCT, and ATB (0, +) transporters and to identify a prodrug with enhanced delivery to the back of the eye. Method Dimethylamino-propyl, carboxy-propyl, and amino-propyl(2-methyl) derivatives of gatifloxacin (GFX), DMAP-GFX, CP-GFX, and APM-GFX, were designed and synthesized to target OCT, MCT, and ATB (0, +) transporters, respectively. LC-MS method was developed to analyze drug and prodrug levels in various studies. Solubility and Log D (pH 7.4) were measured for prodrugs and the parent drug. Permeability of the prodrugs was determined in cornea, conjunctiva, and sclera-choroidretinal pigment epitheluim (SCRPE) and compared with gatifloxacin using Ussing chamber assembly. Permeability mechanisms were elucidated by determining the transport in the presence of transporter specific inhibitors. 1-Methyl-4-phenylpyridinium iodide (MPP+), nicotinic acid sodium salt, and ?-methyl-DL-tryptophan were used to inhibit OCT, MCT, and ATB (0, +) transporters, respectively. A prodrug selected based on in vitro studies was administered as an eye drop to pigmented rabbits and the delivery to various eye tissues including vitreous humor was compared with gatifloxacin dosing. Results DMAP-GFX exhibited 12.8-fold greater solubility than GFX. All prodrugs were more lipophilic, with the measured Log D (pH 7.4) values ranging from 0.05 to 1.04, when compared to GFX (Log D: -1.15). DMAP-GFX showed 1.4-, 1.8-, and 1.9-fold improvement in permeability across cornea, conjunctiva, as well as SCRPE when compared to GFX. Moreover, it exhibited reduced permeability in the presence of MPP+ (competitive inhibitor of OCT), indicating OCT-mediated transport. CP-GFX showed 1.2-, 2.3- and 2.5-fold improvement in permeability across cornea, conjunctiva and SCRPE, respectively. In the presence of nicotinic acid (competitive inhibitor of MCT), permeability of CP-GFX was reduced across conjunctiva. However, cornea and SCRPE permeability of CP-GFX was not affected by nicotinic acid. APM-GFX did not show any improvement in permeability when compared to GFX across cornea, conjunctiva, and SCRPE. Based on solubility and permeability, DMAP-GFX was selected for in vivo studies. DMAP-GFX showed 3.6- and 1.95-fold higher levels in vitreous humor and CRPE compared to that of GFX at 1 hour after topical dosing. In vivo conversion of DMAP-GFX prodrug to GFX was quantified in tissues isolated at 1 hour after dosing. Prodrug-to-parent drug ratio was 8, 70, 24, 21, 29, 13, 55, and 60 % in cornea, conjunctiva, iris-ciliary body, aqueous humor, sclera, CRPE, retina, and vitreous humor, respectively. Conclusions DMAP-GFX prodrug enhanced solubility, Log D, as well as OCT mediated delivery of gatifloxacin to the back of the eye. PMID:23003105

Vooturi, Sunil K.; Kadam, Rajendra S.; Kompella, Uday B.



HSA nanocapsules functionalized with monoclonal antibodies for targeted drug delivery.  


The chronic autoimmune disorder rheumatoid arthritis (RA) affects millions of adults and children every year. Chronically activated macrophages secreting enzymes and inflammatory cytokines play a key role in RA. Distinctive marker molecules on the macrophage surface could be used to design a targeted drug delivery device for the treatment of RA without affecting healthy cells and tissues. Here, different methods for covalent attachment of antibodies (mAb) recognizing MHC class II molecules found on macrophages onto human serum albumin (HSA) nanocapsules were compared. HSA nanocapsules were prepared with a hydrodynamic diameter of 500.7 ± 9.4 nm and a narrow size distribution as indicated by a polydispersity index (PDI) of 0.255 ± 0.024. This was achieved by using a sonochemical process avoiding toxic cross linking agents and emulsifiers. Covalent binding of mAb on the surface of HSA nanocapsules was realized using polyethyleneglycol (PEG)3000 as spacer molecule. The presence of mAb was confirmed by confocal laser scanning microscopy (CLSM) and enzyme-linked immunosorbent assay (ELISA). Specific binding of mAb-HSA nanocapsules to MHC class II molecules on antigen-presenting cells was demonstrated by flow cytometry analysis. PMID:24157344

Rollett, Alexandra; Reiter, Tamara; Ohradanova-Repic, Anna; Machacek, Christian; Cavaco-Paulo, Artur; Stockinger, Hannes; Guebitz, Georg M



PECAM-targeted delivery of SOD inhibits endothelial inflammatory response.  


Elevated generation of reactive oxygen species (ROS) by endothelial enzymes, including NADPH-oxidase, is implicated in vascular oxidative stress and endothelial proinflammatory activation involving exposure of vascular cell adhesion molecule-1 (VCAM-1). Catalase and superoxide dismutase (SOD) conjugated with antibodies to platelet/endothelial cell adhesion molecule 1 (PECAM-1) bind specifically to endothelium and inhibit effects of corresponding ROS, H(2)O(2), and superoxide anion. In this study, anti-PECAM/SOD, but not anti-PECAM/catalase or nontargeted enzymes, including polyethylene glycol (PEG)-SOD, inhibited 2- to 3-fold VCAM expression caused by tumor necrosis factor (TNF), interleukin-1?, and lipopolysaccharide. Anti- PECAM/SOD, but not nontargeted counterparts, accumulated in vascular endothelium after intravenous injection, localized in endothelial endosomes, and inhibited by 70% lipopolysaccharide-caused VCAM-1 expression in mice. Anti-PECAM/SOD colocalized with EEA-1-positive endothelial vesicles and quenched ROS produced in response to TNF. Inhibitors of NADPH oxidase and anion channel ClC3 blocked TNF-induced VCAM expression, affirming that superoxide produced and transported by these proteins, respectively, mediates inflammatory signaling. Anti-PECAM/SOD abolished VCAM expression caused by poly(I:C)-induced activation of toll-like receptor 3 localized in intracellular vesicles. These results directly implicate endosomal influx of superoxide in endothelial inflammatory response and suggest that site-specific interception of this signal attained by targeted delivery of anti-PECAM/SOD into endothelial endosomes may have anti-inflammatory effects. PMID:20876216

Shuvaev, Vladimir V; Han, Jingyan; Yu, Kevin J; Huang, Shaohui; Hawkins, Brian J; Madesh, Muniswamy; Nakada, Marian; Muzykantov, Vladimir R



Glycyrrhetinic Acid-Poly(ethylene glycol)-glycyrrhetinic Acid Tri-Block Conjugates Based Self-Assembled Micelles for Hepatic Targeted Delivery of Poorly Water Soluble Drug  

PubMed Central

The triblock 18?-glycyrrhetinic acid-poly(ethylene glycol)-18?-glycyrrhetinic acid conjugates (GA-PEG-GA) based self-assembled micelles were synthesized and characterized by FTIR, NMR, transmission electron microscopy, and particle size analysis. The GA-PEG-GA conjugates having the critical micelle concentration of 6 × 10?5?M were used to form nanosized micelles, with mean diameters of 159.21 ± 2.2?nm, and then paclitaxel (PTX) was incorporated into GA-PEG-GA micelles by self-assembly method. The physicochemical properties of the PTX loaded GA-PEG-GA micelles were evaluated including in vitro cellular uptake, cytotoxicity, drug release profile, and in vivo tissue distribution. The results demonstrate that the GA-PEG-GA micelles had low cytotoxicity and good ability of selectively delivering drug to hepatic cells in vitro and in vivo by the targeting moiety glycyrrhetinic acid. In conclusion, the GA-PEG-GA conjugates have potential medical applications for targeted delivery of poor soluble drug delivery. PMID:24376388

Xu, Ting; Liu, Chi; Chen, Can; Song, Xiangrong; Zheng, Yu



Near-infrared light-triggered, targeted drug delivery to cancer cells by aptamer gated nanovehicles.  


A novel cell-targeting, near-infrared light-responsive drug delivery platform based on mesoporous silica-coated gold nanorods that are surface-functionalized with aptamer DNA is constructed. Aptamer DNA is used as both capping and targeting agent. In vitro studies show the feasibility of using this nanocarrier for targeted and noninvasive remote controlled drug delivery and photothermal therapy. PMID:22539076

Yang, Xinjian; Liu, Xia; Liu, Zhen; Pu, Fang; Ren, Jinsong; Qu, Xiaogang



Engineering targeted proteins for intracellular delivery of biotherapeutics  

E-print Network

Biotherapeutics have revolutionized medicine with their ability to achieve unprecedented molecular recognition and mediate complex biological responses. The intracellular delivery of biotherapeutics is an unmet scientific ...

Pirie, Christopher M



Exploring targeted pulmonary delivery for treatment of lung cancer  

PubMed Central

Lung cancer is the most malignant cancer today. The treatment of lung cancer continues to be a challenge for oncologists. The direct delivery of chemotherapeutic agents to the lungs could represent a novel therapeutic approach for patients with pulmonary metastases. The large alveolar surface area, the low thickness of the epithelial barrier, and an extensive vascularization make the pulmonary route an ideal route for administration of oncolytics. This paper reviews the research performed over the last and current decades on the delivery of various oncolytics for pulmonary delivery for the treatment of lung cancer. Inhaled drug delivery devices in cancer therapy are also discussed in the present manuscript. PMID:23799201

Goel, Amit; Baboota, Sanjula; Sahni, Jasjeet K; Ali, Javed



Abstract --This paper studies the use of the innovative concept of MRI-targeted drug delivery platform for robotic  

E-print Network

Abstract -- This paper studies the use of the innovative concept of MRI-targeted drug delivery by external magnetic fields. I. INTRODUCTION Drug delivery of chemotherapy agents using aerosolized liposomes for intravascular targeted drug delivery and proved that targeting to specific lesions could be achieved by locating

Mavroidis, Constantinos


Polymeric Micelles for Delivery of Poorly Soluble Drugs: Preparation and Anticancer Activity In Vitro of Paclitaxel Incorporated into Mixed Micelles Based on Poly(ethylene Glycol)-Lipid Conjugate and Positively Charged Lipids  

PubMed Central

Paclitaxel-loaded mixed polymeric micelles consisting of poly(ethylene glycol)-distearoyl phosphoethanolamine conjugates (PEG-PE), solid triglycerides (ST), and cationic Lipofectin® lipids (LL) have been prepared. Micelles with the optimized composition (PEG-PE/ST/LL/paclitaxel = 12/12/2/1 by weight) had an average micelle size of about 100 nm, and zeta-potential of about 26 mV. Micelles were stable and did not release paclitaxel when stored at 4°C in the darkness (just 2.9% of paclitaxel have been lost after 4 months with the particle size remaining unchanged). The release of paclitaxel from such micelles at room temperature was also insignificant. However, at 37°C, approx. 16% of paclitaxel was released from PEG-PE/ST/LL/paclitaxel micelles in 72 h, probably, because of phase transition in the ST-containing micelle core. In vitro anticancer effects of PEG-PE/ST/LL/paclitaxel and control micelles were evaluated using human mammary adenocarcinoma (BT-20) and human ovarian carcinoma (A2780) cell lines. Paclitaxel in PEG-PE/ST/LL micelles demonstrated the maximum anti-cancer activity. Cellular uptake of fluorescently-labeled paclitaxel-containing micelles by BT-20 cells was investigated using a fluorescence microscopy. It seems that PEG-PE/ST/LL micelles, unlike micelles without the LL component, could escape from endosomes and enter the cytoplasm of BT-20 cancer cells thus increasing the anticancer efficiency of the micellar paclitaxel. PMID:15848957




Multifunctional magnetic silica nanotubes for MR imaging and targeted drug delivery.  


A multifunctional drug delivery vehicle consisting of a tubular shaped silica host, a compact superparamagnetic iron oxide nanoparticle layer and a hyaluronic acid surface coating was developed as a theranostic platform, for in vivo MR imaging and magnetically guided/cancer targeted drug delivery. PMID:25656155

Huang, Liang; Ao, Lijiao; Wang, Wei; Hu, Dehong; Sheng, Zonghai; Su, Wu



Near Infrared-Sensitive Nanoparticles for Targeted Drug Delivery  

E-print Network

The invasive nature and undesirable side-effects related to conventional cancer therapy, such as surgery and chemotherapy, have led to the development of novel drug delivery systems (DDS). A minimally invasive DDS using ...

Tan, Mei Chee


Nano to micro delivery systems: targeting angiogenesis in brain tumors  

PubMed Central

Treating brain tumors using inhibitors of angiogenesis is extensively researched and tested in clinical trials. Although anti-angiogenic treatment holds a great potential for treating primary and secondary brain tumors, no clinical treatment is currently approved for brain tumor patients. One of the main hurdles in treating brain tumors is the blood brain barrier - a protective barrier of the brain, which prevents drugs from entering the brain parenchyma. As most therapeutics are excluded from the brain there is an urgent need to develop delivery platforms which will bypass such hurdles and enable the delivery of anti-angiogenic drugs into the tumor bed. Such delivery systems should be able to control release the drug or a combination of drugs at a therapeutic level for the desired time. In this mini-review we will discuss the latest improvements in nano and micro drug delivery platforms that were designed to deliver inhibitors of angiogenesis to the brain. PMID:20932320



NEST Scientific Report 2007-2009 Nanotechnology for intracellular delivery and targeting of drugs, nanoreporters  

E-print Network

NEST Scientific Report 2007-2009 Nanotechnology for intracellular delivery and targeting of drugs to the Collaborators A. Albanese L. Albertazzi F. Beltram R. Bizzarri F. Cardarelli F. Salomone #12;Nanotechnology

Abbondandolo, Alberto


Cell-mediated Delivery and Targeted Erosion of Noncovalently Crosslinked Hydrogels  

NASA Technical Reports Server (NTRS)

A method for targeted delivery of therapeutic compounds from hydrogels is presented. The method involves administering to a cell a hydrogel in which a therapeutic compound is noncovalently bound to heparin.

Kiick, Kristi L. (Inventor); Yamaguchi, Nori (Inventor)



Quantification of Mesenchymal Stem Cell (MSC) Delivery to a Target Site Using In Vivo Confocal Microscopy  

E-print Network

The ability to deliver cells to appropriate target tissues is a prerequisite for successful cell-based therapy. To optimize cell therapy it is therefore necessary to develop a robust method of in vivo cell delivery ...

Mortensen, Luke J.


A Nonpolycationic Fully Proteinaceous Multiagent System for Potent Targeted Delivery of siRNA  

E-print Network

Protein-based methods of targeted short-interfering RNA (siRNA) delivery have the potential to solve some of the problems faced by nanoparticle-based methods, such as poor pharmacokinetics and biodistribution, low tumor ...

Liu, David V.


Enhanced oral delivery of paclitaxel using acetylcysteine functionalized chitosan-vitamin E succinate nanomicelles based on a mucus bioadhesion and penetration mechanism.  


In addition to being a physiological protective barrier, the gastrointestinal mucosal membrane is also a primary obstacle that hinders the oral absorption of many therapeutic compounds, especially drugs with a poor permeability. In order to resolve this impasse, we have designed multifunctional nanomicelles based on the acetylcysteine functionalized chitosan-vitamin E succinate copolymer (CS-VES-NAC, CVN), which exhibit marked bioadhesion, possess the ability to penetrate mucus, and enhance the oral absorption of a hydrophobic drug with a poor penetrative profile, paclitaxel. The intestinal absorption (Ka = 0.38 ± 0.04 min(-1), Papp = 0.059 cm · min(-1)) of CVN nanomicelles was greatly improved (4.5-fold) in comparison with paclitaxel solution, and CLSM (confocal laser scanning microscope) pictures also showed not only enhanced adhesion to the intestinal surface but improved accumulation within intestinal villi. The in vivo pharmacokinetics indicated that the AUC0-t (586.37 ng/mL · h) of CVN nanomicelles was markedly enhanced compared with PTX solution. In summary, the novel multifunctional CVN nanomicelles appear to be a promising nanocarrier for insoluble and poorly permeable drugs due to their high bioadhesion and permeation-enhancing capability. PMID:23909663

Lian, He; Zhang, Tianhong; Sun, Jin; Liu, Xiaohong; Ren, Guolian; Kou, Longfa; Zhang, Youxi; Han, Xiaopeng; Ding, Wenya; Ai, Xiaoyu; Wu, Chunnuan; Li, Lin; Wang, Yongjun; Sun, Yinghua; Wang, Siling; He, Zhonggui



The role of HER2 in cancer therapy and targeted drug delivery  

PubMed Central

HER2 is highly expressed in a significant proportion of breast cancer, ovarian cancer, and gastric cancer. Since the discovery of its role in tumorigenesis, HER2 has received great attention in cancer research during the past two decades. Successful development of the humanized monoclonal anti-HER2 antibody (Trastuzumab) for the treatment of breast cancer further spurred scientists to develop various HER2 specific antibodies, dimerization inhibitors and kinase inhibitors for cancer therapy. On the other hand, the high expression of HER2 and the accessibility of its extracellular domain make HER2 an ideal target for the targeted delivery of anti-tumor drugs as well as imaging agents. Although there is no natural ligand for HER2, various artificial ligands targeting HER2 have been developed and applied in various targeted drug delivery systems. The emphasis of this review is to elucidate the roles of HER2 in cancer therapy and targeted drug delivery. The structure and signal pathway of HER2 will be briefly described. The role of HER2 in tumorigenesis and its relationship with other tumor markers will be discussed. For the HER2 targeted cancer therapy, numerous strategies including the blockage of receptor dimerization, inhibition of the tyrosine kinase activity, and interruption of the downstream signal pathway will be summarized. For the targeted drug delivery to HER2 positive tumor cells, various targeting ligands and their delivery systems will be described in details. PMID:20385184

Tai, Wanyi; Mahato, Rubi; Cheng, Kun



Nanostructured lipid carriers and their current application in targeted drug delivery.  


In the last few decades, various drug-delivery technologies have emerged and a fascinating part of this has been the development of nanoscale drug delivery devices. Nanoparticles (NPs) and other colloidal drug-delivery systems modify the kinetics, drug distribution in the body and release profile of an associated drug. Nanostructured lipid carriers (NLCs) have been reported to be an alternative system to emulsions, liposomes, microparticles, solid lipid nanoparticles (SLNs) and their polymeric counterparts due to their numerous advantages. This paper basically reviews the types of NLCs, mechanism of skin penetration, stability related issues along with their production techniques, characterisation and applications towards targeted drug delivery. PMID:24813223

Jaiswal, Piyush; Gidwani, Bina; Vyas, Amber



A Novel Lanreotide-Encoded Micelle System Targets Paclitaxel to the Tumors with Overexpression of Somatostatin Receptors  

E-print Network

and cytotoxicity studies, lanreotide-encoded PEG-b-PCL micelles demonstrated more specific cell uptake and cytotoxicity in SSTR2-positive tumor cells via a receptor-mediated mechanism over the passive targeting) are core-shell nanoparticles (5-100 nm in diameter) that are self-assembled from amphiphilic blocks

Gao, Jinming


Calcium-crosslinked LABL-TAT complexes effectively target gene delivery to ICAM-1 expressing cells  

PubMed Central

Targeted gene delivery using non-viral vectors is a highly touted scheme to reduce the potential for toxic or immunological side effects by reducing dose. In previous reports, TAT polyplexes with DNA have shown relatively poor gene delivery. The transfection efficiency has been enhanced by condensing TAT/DNA complexes to a small particle size using calcium. To explore the targetability of these condensed TAT complexes, LABL peptide targeting intercellular cell-adhesion molecule-1 (ICAM-1) was conjugated to TAT peptide using a polyethylene glycol (PEG) spacer. PEGylation reduced the transfection efficiency of TAT, but TAT complexes targeting ICAM-1 expressing cells regained much of the lost transfection efficiency. Targeted block peptides properly formulated with calcium offer promise for gene delivery to ICAM-1 expressing cells at sites of injury or inflammation. PMID:21473630

Khondee, Supang; Baoum, Abdulgader; Siahaan, Teruna J.; Berkland, Cory



Battling with environments: drug delivery to target tissues with particles and functional biomaterials  

PubMed Central

Recent years have seen a growing interest in drug-delivery technology as an enabling tool for complicated pharmacological activities. At the same time, this field has faced as many ideas into clinical benefits. The Laboratory for Therapeutic Particles and Biomaterials Engineering at Purdue University (IN, USA) has striven to identify the current challenges in drug delivery and find solutions through the design of new drug-delivery systems. We develop new inhalable formulations for drug and gene delivery for cystic fibrosis patients, simple particle platforms for inhalable drug delivery, anion-resistant nonviral gene vectors, tumor-targeted nanoparticle systems, and hydrogel-based therapeutics. Through expanded collaborations with researchers in medicine and related disciplines, we strive to contribute to advancing the drug delivery field in a clinically relevant manner. PMID:21339855

Yeo, Yoon



Solid lipid nanoparticles for targeted brain drug delivery  

Microsoft Academic Search

The present review discusses the potential use of solid lipid nanoparticles for brain drug targeting purposes. The state of the art on surfactant-coated poly(alkylcyanoacrylate) nanoparticles specifically designed for brain targeting is given by emphasizing the transfer of this technology to solid lipid matrices. The available literature on solid lipid nanoparticles and related carriers for brain drug targeting is revised as

Paolo Blasi; Stefano Giovagnoli; Aurélie Schoubben; Maurizio Ricci; Carlo Rossi



Cell Penetrating and Cell Targeting Peptides in Drug Delivery (revised version) Eric Vivs*, Julien Schmidt and Andr Plegrin.  

E-print Network

1 Cell Penetrating and Cell Targeting Peptides in Drug Delivery (revised version) Eric Vivès-penetrating peptide, cell-targeting peptide, cell delivery, drug. Abstract During the last decade, the potential of peptides for drug delivery into cells has been highlighted by the discovery of several cell

Paris-Sud XI, Université de


Ferri-liposomes as an MRI-visible drug-delivery system for targeting tumours and their  

E-print Network

Ferri-liposomes as an MRI-visible drug-delivery system for targeting tumours-invasively monitor drug delivery in vivo. We also visualize the targeting of the tumour microenvironment by the drug substantially reduced the size of the tumour compared with systemic delivery of the same drug. C ancer

Bogyo, Matthew


Cell targeted gene delivery system based on modified pectin  

Technology Transfer Automated Retrieval System (TEKTRAN)

Citrus pectin modified with various amine groups have been studied for its potential as a novel non-viral gene delivery carrier. The modified cationic pectin was able to condense DNA and mediate transfection in a cell type specific manner. The modified pectin seems to be a promising carrier, attra...


Polymeric nanofibers: targeted gastro-retentive drug delivery systems.  


Abstract Background: Conventional oral dosage forms exhibit poor/low bioavailability due to incomplete release of drug and short residence time at the absorption site. Gastro-retentive drug delivery system (GRDDS) is particularly used to improve bioavailability of the drugs, which have narrow absorption window down in the levels of gastrointestinal tract and also to treat local disorders. Purpose: The purpose of this review is to describe the utility of the nanofibers as gastro-retentive dosage form. From last few decades, formulation scientists have put extensive efforts to develop suitable gastro-retentive drug delivery system, which is appropriate for commercialization. Current approaches used for preparation of gastro-retentive drug delivery system offers limited functional features to control the floating behavior. Recently, an extensive research has been developed to improve the gastric residence time by using nanofibers, which ultimately leads to the increased bioavailability of the drug. Multiple functional features and unique properties of nanofibers improve its gastro retention. Conclusion: Nanofiber system provides stomach-specific drug release for longer duration; moreover, increased local action of the drug due to prolonged contact time with the gastric mucosa. Thus, the nanofiber system promises to be the potential approach for gastric retention drug delivery system. PMID:25268275

Malik, Rafi; Garg, Tarun; Goyal, Amit K; Rath, Goutam



[Pharmacological action of paclitaxel].  


Paclitaxel (taxol, Tax) is a novel plant product isolated from the Pacific yew (Taxus brevifolia). It has a unique mechanism of action, because it induces very stable and dysfunctional microtubules. Paclitaxel has a broad spectrum of antineoplastic activity. It has been successfully used in the treatment of ovarian cancer, metastatic breast cancer, lung cancer, carcinoma of the head and neck, malignant melanoma and other human neoplasms. Tax has response rates of 20-36% in patients with refractory ovarian cancer. Toxic effects include myelosuppresion, hypersensitivity reactions, peripheral neuropathy, cardiac disturbances, alopecia. However, studies evaluating the drug still are ongoing paclitaxel seems to be one of the most promising antineoplastic agents. PMID:10344150

Potemski, P; P?uza?ska, A



Protein engineering for targeted delivery of radionuclides to tumors  

E-print Network

Traditional cancer treatment strategies include systemic chemotherapy, external beam radiation, and surgical excision. Chemotherapy is nonspecific, and targets all rapidly dividing cells. External beam radiation and surgery ...

Orcutt, Kelly Davis



Nanomicellar carriers for targeted delivery of anticancer agents  

PubMed Central

Clinical application of anticancer drugs is limited by problems such as low water solubility, lack of tissue-specificity and toxicity. Formulation development represents an important approach to these problems. Among the many delivery systems studied, polymeric micelles have gained considerable attention owing to ease in preparation, small sizes (10–100 nm), and ability to solubilize water-insoluble anticancer drugs and accumulate specifically at the tumors. This article provides a brief review of several promising micellar systems and their applications in tumor therapy. The emphasis is placed on the discussion of the authors’ recent work on several nanomicellar systems that have both a delivery function and antitumor activity, named dual-function drug carriers. PMID:24341817

Zhang, Xiaolan; Huang, Yixian; Li, Song



Co-delivery of drugs and DNA from cationic core-shell nanoparticles self-assembled from a biodegradable copolymer  

NASA Astrophysics Data System (ADS)

Non-viral gene-delivery systems are safer to use and easier to produce than viral vectors, but their comparatively low transfection efficiency has limited their applications. Co-delivery of drugs and DNA has been proposed to enhance gene expression or to achieve the synergistic/combined effect of drug and gene therapies. Attempts have been made to deliver drugs and DNA simultaneously using liposomes. Here we report cationic core-shell nanoparticles that were self-assembled from a biodegradable amphiphilic copolymer. These nanoparticles offer advantages over liposomes, as they are easier to fabricate, and are more readily subject to modulation of their size and degree of positive charge. More importantly, they achieve high gene-transfection efficiency and the possibility of co-delivering drugs and genes to the same cells. Enhanced gene transfection with the co-delivery of paclitaxel has been demonstrated by in vitro and in vivo studies. In particular, the co-delivery of paclitaxel with an interleukin-12-encoded plasmid using these nanoparticles suppressed cancer growth more efficiently than the delivery of either paclitaxel or the plasmid in a 4T1 mouse breast cancer model. Moreover, the co-delivery of paclitaxel with Bcl-2-targeted small interfering RNA (siRNA) increased cytotoxicity in MDA-MB-231 human breast cancer cells.

Wang, Yong; Gao, Shujun; Ye, Wen-Hui; Yoon, Ho Sup; Yang, Yi-Yan



Local delivery of nitric oxide: targeted delivery of therapeutics to bone and connective tissues  

PubMed Central

Non-invasive treatment of injuries and disorders affecting bones and connective tissue is a significant challenge facing the medical community. A treatment route that has recently been proposed is nitric oxide (NO) therapy. Nitric oxide plays several roles in physiology with many conditions lacking adequate levels of NO. As NO is a radical, localized delivery via NO donors is essential to promoting biological activity. Herein, we review current literature related to therapeutic NO delivery in the treatment of bone, skin and tendon repair. PMID:22433782

Nichols, Scott P.; Storm, Wesley L.; Koh, Ahyeon; Schoenfisch, Mark H.



Magnetic Targeted Delivery of Dexamethasone Acetate across the Round Window Membrane in Guinea Pigs  

PubMed Central

Hypothesis Magnetically susceptible PLGA nanoparticles will effectively target the round window membrane (RWM) for delivery of dexamethasone-acetate (Dex-Ac) to the scala tympani. Background Targeted delivery of therapeutics to specific tissues can be accomplished using different targeting mechanisms. One technology includes iron oxide nanoparticles, susceptible to external magnetic fields. If a nanocomposite composed of biocompatible polymer (PLGA), magnetite, and Dex-Ac can be pulled into and across the mammalian RWM, drug delivery can be enhanced. Method In vitro targeting and release kinetics of PLGA-magnetite-Dex-Ac nanoparticles first were measured using a RWM model. Next, these optimized nanocomposites were targeted to the RWM by filling the niche in anesthetized guinea pigs. A permanent magnet was placed opposite the RWM for 1 hour. Cochlear soft tissues, perilymph, and RWM were harvested after euthanasia and steroid levels were measured using HPLC. Results Membrane transport, in vitro, proved optimal targeting using a lower particle magnetite concentration (1 versus 5 or 10 mg/ml). In vivo targeted PLGA-magnetite-Dex-Ac particles had an average size of 482.8 ± 158 nm (DLS) and an average zeta potential ?19.9 ± 3.3 mV. In 1 hour, there was significantly increased cochlear targeted delivery of Dex or Dex-Ac, compared with diffusion alone. Conclusion Superparamagnetic PLGA-magnetite-Dex-Ac nanoparticles under an external magnetic field (0.26 mT) for 1 hour significantly increased Dex-Ac delivery to the inner ear. The RWM was not completely permeated and also became loaded with nanocomposites, indicating that delivery to the cochlea would continue for weeks by PLGA degradation and passive diffusion. PMID:23187928

Du, Xiaoping; Chen, Kejian; Kuriyavar, Satish; Kopke, Richard D.; Grady, Brian P.; Bourne, David H.; Li, Wei; Dormer, Kenneth J.



Conceptual design report for the University of Rochester cryogenic target delivery system  

SciTech Connect

The upgrade of the Omega laser at the University of Rochester's Laboratory for Laser Energetics (UR/LLE) will result in a need for large targets filled with D[sub 2] or Dt and maintained at cryogenic temperatures. This mandates a cryogenic target delivery system capable of filling, layering, characterizing and delivering cryogenic targets to the Omega Upgrade target chamber. The program goal is to design, construct, and test the entire target delivery system by June 1996. When completed (including an operational demonstration), the system will be shipped to Rochester for reassembly and commissioning in time for the Omega Upgrade cryogenic campaign, scheduled to start in 1998. General Atomics has been assigned the task of developing the conceptual design for the cryogenic target delivery system. Design and fabrication activities will be closely coordinated with the University of Rochester, Lawrence Livermore National laboratory (LLNL) and Los Alamos National Laboratory (LANL), drawing upon their knowledge base in fuel layering and cryogenic characterization. The development of a target delivery system for Omega could also benefit experiments at Lawrence Livermore National Laboratory and the other ICF Laboratories in that the same technologies could be applied to NOVA, the National Ignition Facility or the future Laboratory Microfusion Facility.

Fagaly, R.L.; Alexander, N.B.; Bourque, R.F.; Dahms, C.F.; Lindgren, J.R.; Miller, W.J. (General Atomics, San Diego, CA (United States)); Bittner, D.N.; Hendricks, C.D. (W.J. Schafer Associates, Livermore, CA (United States))



Conceptual design report for the University of Rochester cryogenic target delivery system  

SciTech Connect

The upgrade of the Omega laser at the University of Rochester`s Laboratory for Laser Energetics (UR/LLE) will result in a need for large targets filled with D{sub 2} or Dt and maintained at cryogenic temperatures. This mandates a cryogenic target delivery system capable of filling, layering, characterizing and delivering cryogenic targets to the Omega Upgrade target chamber. The program goal is to design, construct, and test the entire target delivery system by June 1996. When completed (including an operational demonstration), the system will be shipped to Rochester for reassembly and commissioning in time for the Omega Upgrade cryogenic campaign, scheduled to start in 1998. General Atomics has been assigned the task of developing the conceptual design for the cryogenic target delivery system. Design and fabrication activities will be closely coordinated with the University of Rochester, Lawrence Livermore National laboratory (LLNL) and Los Alamos National Laboratory (LANL), drawing upon their knowledge base in fuel layering and cryogenic characterization. The development of a target delivery system for Omega could also benefit experiments at Lawrence Livermore National Laboratory and the other ICF Laboratories in that the same technologies could be applied to NOVA, the National Ignition Facility or the future Laboratory Microfusion Facility.

Fagaly, R.L.; Alexander, N.B.; Bourque, R.F.; Dahms, C.F.; Lindgren, J.R.; Miller, W.J. [General Atomics, San Diego, CA (United States); Bittner, D.N.; Hendricks, C.D. [W.J. Schafer Associates, Livermore, CA (US)



Lipid-Coated Nanoscale Coordination Polymers for Targeted Delivery of Antifolates to Cancer Cells  

PubMed Central

Nanoscale coordination polymers (NCPs) have been demonstrated as an interesting platform for drug delivery, as they possess many advantages over small-molecule chemotherapeutics, such as high payloads, lower systemic toxicity, tunability, and enhanced tumor uptake. Existing formulations for the delivery of methotrexate (MTX), an antifolate cancer drug, have very low drug loadings. Herein, we report the incorporation of MTX as a building block in an NCP formulation with exceptionally high drug loadings (up to 79.1 wt%) and the selective delivery of the NCP to cancer cells. Encapsulation of the NCP in a functionalized lipid bilayer allows for targeted delivery and controlled release to cancer cells. A phosphor can be doped into the NCPs for monitoring particle uptake by optical imaging. The lipid-coated and anisamide-targeted NCPs have superior in vitro efficacy against acute lymphoblastic leukemia cells when compared to free drug. PMID:24288587

Huxford, Rachel C.; deKrafft, Kathryn E.; Boyle, William S.; Liu, Demin



New Lipid and Glycolipid-Based Nanosystems for Targeted Gene Delivery: Cholenims, Glycoclips, Glycolipids and Chitosan  

Microsoft Academic Search

Cationic lipid vesicles and polypeptides represent common non-viral gene delivery systems for in vitro and in vivo applications.\\u000a New non-viral vectors for targeted gene delivery, namely, mono-, di- and tricholesterol derivatives of oligoethyleneimine,\\u000a glycolipids and chitosan derivatives are reported in this chapter. Testing of genotoxicity, cytotoxicity and gene transfer\\u000a activity against transformed monolayer and suspension cell cultures is carried out

R. I. Zhdanov; E. V. Bogdanenko; T. V. Zarubina; S. I. Dominova; G. G. Krivtsov; A. S. Borisenko; A. S. Bogdanenko; G. A. Serebrennikova; Yu. L. Sebyakin; V. V. Vlassov


Aptamer-targeted DNA nanostructures for therapeutic delivery.  


DNA-based nanostructures have been widely used in various applications due to their structural diversity, programmability, and uniform structures. Their intrinsic biocompatibility and biodegradability further motivates the investigation of DNA-based nanostructures as delivery vehicles. Incorporating AS1411 aptamers into DNA pyramids leads to enhanced intracellular uptake and selectively inhibits the growth of cancer cells, achieved without the use of transfection reagents. Furthermore, aptamer-displaying pyramids are found to be substantially more resistant to nuclease degradation than single-stranded aptamers. These findings, along with their modularity, reinforce the potential of DNA-based nanostructures for therapeutic applications. PMID:24739136

Charoenphol, Phapanin; Bermudez, Harry



PR_b-targeted delivery of tumor necrosis factor-a by polymersomes for the treatment of prostate cancer  

E-print Network

PR_b-targeted delivery of tumor necrosis factor-a by polymersomes for the treatment of prostate. In this study we design and assess peptide functionalized polymer vesicles, or polymersomes, self assembled from of these PR_b-targeted polymersomes show great promise for the targeted delivery of therapeutics. Introduction

Kokkoli, Efie


Challenges in design and characterization of ligand-targeted drug delivery systems  

PubMed Central

Targeting of therapeutic agents to molecular markers expressed on the surface of cells requiring clinical intervention holds promise to improve specificity of delivery, enhancing therapeutic effects while decreasing potential damage to healthy tissues. Drug targeting to cellular receptors involved in endocytic transport facilitates intracellular delivery, a requirement for a number of therapeutic goals. However, after several decades of experimental design, there is still considerable controversy on the practical outcome of drug targeting strategies. The plethora of factors contributing to the relative efficacy of targeting makes the success of these approaches hardly predictable. Lack of fully specific targets, along with selection of targets with spatial and temporal expression well aligned to interventional requirements, pose difficulties to this process. Selection of adequate sub-molecular target epitopes determines accessibility for anchoring of drug conjugates and bulkier drug carriers, as well as proper signaling for uptake within the cell. Targeting design must adapt to physiological variables of blood flow, disease status, and tissue architecture by accommodating physicochemical parameters such as carrier composition, functionalization, geometry, and avidity. In many cases, opposite features need to meet a balance, e.g., sustained circulation versus efficient targeting, penetration through tissues versus uptake within cells, internalization within endocytic compartment to avoid efflux pumps versus accessibility to molecular targets within the cytosol, etc. Detailed characterization of these complex physiological factors and design parameters, along with a deep understanding of the mechanisms governing the interaction of targeted drugs and carriers with the biological environment, are necessary steps toward achieving efficient drug targeting systems. PMID:22709588

Muro, Silvia



Dendritic polymer-based nanodevices for targeted drug delivery applications  

NASA Astrophysics Data System (ADS)

Dendrimers and hyperbranched polymers are unimolecular micellar nanostructures, characterized by globular shape ( ˜ 20 nm) and large density of functional groups at periphery. The tailorable end groups make them ideal for conjugation with drugs, ligands, and imagining agents, making them an attractive molecular nanodevices for drug delivery. Compared to linear polymers and nanoparticles, these nanodevices enter cells rapidly, carrying drugs and delivering them inside cells. Performance of nanodevices prepared for asthma and cancer drug delivery will be discussed. Our conjugation procedure produced very high drug payloads. Dendritic polymer-drug conjugates were very effective in transporting methotrexate (a chemotherapy drug) into both sensitive (CCRF-CEM cell line) and resistant cell line (CEM-MTX). The conjugate nanodevice was 3 times more effective than free drug in the sensitive line, and 9 times more effective in the resistant cell line (based on IC50). The physics of cell entry and drug release from these nanodevices are being investigated. The conjugates appear to enter cells through endocytosis, with the rate of entry dependent on end-group, molecular weight, the pH of the medium, and the cancerous nature of the cells.

Kannan, R. M.; Kolhe, Parag; Gurdag, Sezen; Khandare, Jayant; Lieh-Lai, Mary



Targeted Delivery System of Nanobiomaterials in Anticancer Therapy: From Cells to Clinics  

PubMed Central

Targeted delivery systems of nanobiomaterials are necessary to be developed for the diagnosis and treatment of cancer. Nanobiomaterials can be engineered to recognize cancer-specific receptors at the cellular levels and to deliver anticancer drugs into the diseased sites. In particular, nanobiomaterial-based nanocarriers, so-called nanoplatforms, are the design of the targeted delivery systems such as liposomes, polymeric nanoparticles/micelles, nanoconjugates, norganic materials, carbon-based nanobiomaterials, and bioinspired phage system, which are based on the nanosize of 1–100?nm in diameter. In this review, the design and the application of these nanoplatforms are discussed at the cellular levels as well as in the clinics. We believe that this review can offer recent advances in the targeted delivery systems of nanobiomaterials regarding in vitro and in vivo applications and the translation of nanobiomaterials to nanomedicine in anticancer therapy. PMID:24672796

Jin, Su-Eon; Jin, Hyo-Eon; Hong, Soon-Sun



Tuning Pharmacokinetics and Biodistribution of a Targeted Drug Delivery System Through Incorporation of a Passive Targeting Component  

PubMed Central

Major challenges in the development of drug delivery systems (DDSs) have been the short half-life, poor bioavailability, insufficient accumulation and penetration of the DDSs into the tumor tissue. Understanding the pharmacokinetic (PK) parameters of the DDS is essential to overcome these challenges. Herein we investigate how surface chemistry affects the PK profile and organ distribution of a gold nanoparticle-based DDS containing both a passive and active targeting moiety via two common routes of administration: intravenous and intraperitoneal injections. Using LC/MS/MS, ELISA and INAA we report the half-life, peak plasma concentrations, area under the curve, ability to cross the peritoneal barrier and biodistribution of the nanoconjugates. The results highlight the design criteria for fine-tuning the PK parameters of a targeted drug delivery system that exploits the benefits of both active and passive targeting. PMID:25011609

Kudgus, Rachel A.; Walden, Chad A.; McGovern, Renee M.; Reid, Joel M.; Robertson, J. David; Mukherjee, Priyabrata



Impacts of Blood-Brain Barrier in Drug Delivery and Targeting of Brain Tumors  

PubMed Central

Introduction Entry of blood circulating agents into the brain is highly selectively con-trolled by specific transport machineries at the blood brain barrier (BBB), whose excellent barrier restrictiveness make brain drug delivery and targeting very challenging. Methods Essential information on BBB cellular microenvironment were reviewed and discussed towards impacts of BBB on brain drug delivery and targeting. Results Brain capillary endothelial cells (BCECs) form unique biological structure and architecture in association with astrocytes and pericytes, in which microenvironment the BCECs express restrictive tight junctional complexes that block the paracellular inward/outward traverse of biomolecules/compounds. These cells selectively/specifically control the transportation process through carrier and/or receptor mediated transport machineries that can also be exploited for the delivery of pharmaceuticals into the brain. Intelligent molecular therapies should be designed using such transport machineries for the efficient delivery of designated drugs into the brain. For better clinical outcomes, these smart pharmaceuticals should be engineered as seamless nanosystems to provide simultaneous imaging and therapy (multimodal theranostics). Conclusion The exceptional functional presence of BBB selectively controls inward and outward transportation mechanisms, thus advanced smart multifunctional nanomedicines are needed for the effective brain drug delivery and targeting. Fully understanding the biofunctions of BBB appears to be a central step for engineering of intelligent seamless therapeutics consisting of homing device for targeting, imaging moiety for detecting, and stimuli responsive device for on-demand liberation of therapeutic agent. PMID:23678437

Omidi, Yadollah; Barar, Jaleh



A polyvalent aptamer system for targeted drug delivery.  


Poor efficacy and off-target systemic toxicity are major problems associated with current chemotherapeutic approaches to treat cancer. We developed a new form of polyvalent therapeutics that is composed of multiple aptamer units synthesized by rolling circle amplification and physically intercalated chemotherapy agents (termed as "Poly-Aptamer-Drug"). Using a leukemia cell-binding aptamer and doxorubicin as a model system, we have successfully constructed Poly-Aptamer-Drug systems and demonstrated that the Poly-Aptamer-Drug is significantly more effective than its monovalent counterpart in targeting and killing leukemia cells due to enhanced binding affinity (? 40 fold greater) and cell internalization via multivalent effects. We anticipate that our Poly-Aptamer-Drug approach will yield new classes of tunable therapeutics that can be utilized to effectively target and treat cancers while minimizing the side effects of chemotherapy. PMID:24044994

Zhang, Zhiqing; Ali, M Monsur; Eckert, Mark A; Kang, Dong-Ku; Chen, Yih Yang; Sender, Leonard S; Fruman, David A; Zhao, Weian



Transcriptional Profiling of Targets for Combination Therapy of Lung Carcinoma with Paclitaxel and Mitogen-activated Protein\\/Extracellular Signal-regulated Kinase Kinase Inhibitor1  

Microsoft Academic Search

A combination of paclitaxel (Taxol) and mitogen-activated protein\\/ extracellular signal-regulated kinase kinase (MEK\\/Erk) inhibitor repre- sents a rational new approach to chemotherapy. We performed Af- fymetrix microarray analysis to understand the global effects of this combination in lung carcinoma. Genes involved in cell cycle control, apoptosis, adhesion, proliferation, invasion, and metastasis were modu- lated. We observed similar patterns of gene

Debra J. Taxman; Jeffrey P. MacKeigan; Casey Clements; Daniel T. Bergstralh



Synthesis and Evaluation of Fluorescent Magnetic Composites as Targeted Drug Delivery Carriers  

NASA Astrophysics Data System (ADS)

We have developed Fe3O4@ZnS-based fluorescent magnetic composites as targeted drug delivery carriers via a facile route. The results indicated that the composites exhibited both magnetic and fluorescent properties. Fe3O4@ZnS possessed high saturation magnetization (68.25 emu/g) at room temperature. Ultraviolet light can be easily obtained by exposing the microspheres to different excitation wavelengths. The drug loading studies showed that Fe3O4@ZnS-based fluorescent magnetic composites had an excellent drug loading performance. These traits made the composites better for the application of medical imaging and magnetic targeted drug delivery.

Jiang, Wei; Chen, Xiaolong; Wu, Juan; Xu, Shanshan; Tian, Renbing



An Efficient Targeted Drug Delivery through Apotransferrin Loaded Nanoparticles  

Microsoft Academic Search

BackgroundCancerous state is a highly stimulated environment of metabolically active cells. The cells under these conditions over express selective receptors for assimilation of factors essential for growth and transformation. Such receptors would serve as potential targets for the specific ligand mediated transport of pharmaceutically active molecules. The present study demonstrates the specificity and efficacy of protein nanoparticle of apotransferrin for

Athuluri Divakar Sai Krishna; Raj Kumar Mandraju; Golla Kishore; Anand Kumar Kondapi



The application of carbon nanotubes in target drug delivery systems for cancer therapies  

PubMed Central

Among all cancer treatment options, chemotherapy continues to play a major role in killing free cancer cells and removing undetectable tumor micro-focuses. Although chemotherapies are successful in some cases, systemic toxicity may develop at the same time due to lack of selectivity of the drugs for cancer tissues and cells, which often leads to the failure of chemotherapies. Obviously, the therapeutic effects will be revolutionarily improved if human can deliver the anticancer drugs with high selectivity to cancer cells or cancer tissues. This selective delivery of the drugs has been called target treatment. To realize target treatment, the first step of the strategies is to build up effective target drug delivery systems. Generally speaking, such a system is often made up of the carriers and drugs, of which the carriers play the roles of target delivery. An ideal carrier for target drug delivery systems should have three pre-requisites for their functions: (1) they themselves have target effects; (2) they have sufficiently strong adsorptive effects for anticancer drugs to ensure they can transport the drugs to the effect-relevant sites; and (3) they can release the drugs from them in the effect-relevant sites, and only in this way can the treatment effects develop. The transporting capabilities of carbon nanotubes combined with appropriate surface modifications and their unique physicochemical properties show great promise to meet the three pre-requisites. Here, we review the progress in the study on the application of carbon nanotubes as target carriers in drug delivery systems for cancer therapies. PMID:21995320



Delivery of Small Interfering RNA by Peptide-Targeted Mesoporous Silica Nanoparticle-Supported Lipid Bilayers  

PubMed Central

The therapeutic potential of small interfering RNAs (siRNAs) is severely limited by the availability of delivery platforms that protect siRNA from degradation, deliver it to the target cell with high specificity and efficiency, and promote its endosomal escape and cytosolic dispersion. Here we report that mesoporous silica nanoparticle-supported lipid bilayers (or ‘protocells’), exhibit multiple properties that overcome many of the limitations of existing delivery platforms. Protocells have a 10- to 100-fold greater capacity for siRNA than corresponding lipid nanoparticles and are markedly more stable when incubated under physiological conditions. Protocells loaded with a cocktail of siRNAs bind to cells in a manner dependent on the presence of an appropriate targeting peptide and, through an endocytic pathway followed by endosomal disruption, promote delivery of the silencing nucleotides to the cytoplasm. The expression of each of the genes targeted by the siRNAs was shown to be repressed at the protein level, resulting in a potent induction of growth arrest and apoptosis. Incubation of control cells that lack expression of the antigen recognized by the targeting peptide with siRNA-loaded protocells induced neither repression of protein expression nor apoptosis, indicating the precise specificity of cytotoxic activity. In terms of loading capacity, targeting capabilities, and potency of action, protocells provide unique attributes as a delivery platform for therapeutic oligonucleotides. PMID:22309035

Ashley, Carlee E.; Carnes, Eric C.; Epler, Katharine E.; Padilla, David P.; Phillips, Genevieve K.; Castillo, Robert E.; Wilkinson, Dan C.; Wilkinson, Brian S.; Burgard, Cameron A.; Sewell, Robin M.; Townson, Jason L.; Chackerian, Bryce; Willman, Cheryl L.; Peabody, David S.; Wharton, Walker; Brinker, C. Jeffrey



A Nonpolycationic Fully Proteinaceous Multiagent System for Potent Targeted Delivery of siRNA.  


Protein-based methods of targeted short-interfering RNA (siRNA) delivery have the potential to solve some of the problems faced by nanoparticle-based methods, such as poor pharmacokinetics and biodistribution, low tumor penetration, and polydispersity. However, protein-based targeted delivery has been limited to fusion proteins with polycationic peptides as siRNA carriers, whose high charge density in some cases results in undesirable biophysical and in vivo properties. Here, we present a fully proteinaceous, multiagent approach for targeted siRNA delivery to epidermal growth factor receptor (EGFR), using a nonpolycationic carrier for siRNA. Each agent contributes a fundamentally different mechanism of action that work together for potent targeted RNA interference. The first agent is an EGFR-targeted fusion protein that uses a double-stranded RNA-binding domain as a nonpolycationic siRNA carrier. This double-stranded RNA-binding domain fusion protein can deliver siRNA to the endosomes of an EGFR-expressing cell line. A second agent delivers the cholesterol-dependent cytolysin, perfringolysin O, in a targeted manner, which enhances the endosomal escape of siRNA and induces gene silencing. A third agent that clusters EGFR increases gene-silencing potency and decreases cytolysin toxicity. Altogether, this system is potent, with only 16 nmol/l siRNA required for gene silencing and a therapeutic window that spans two orders of magnitude of targeted cytolysin concentrations. PMID:24825362

Liu, David V; Yang, Nicole J; Wittrup, K Dane



Methotrexate delivery via folate targeted dendrimer-based nanotherapeutic platform  

PubMed Central

This paper provides a synopsis of the advancements made in advancing a dendrimer-based nanomedicine towards human clinical trials by the Michigan Nanotechnology Institute for Medicine and Biological Sciences. A brief description of the synthesis and characterization of a targeted multifunctional therapeutic will demonstrate the simple yet delicate task of producing novel chemotherapeutic agents. The results obtained from in vitro and in vivo studies not only authenticate the potential of using nanoparticles to target therapeutics but also provide valuable insight towards the future directions of this technology. A fundamental, cross-disciplinary collaboration was necessary to achieve the synthesis and testing of this technology, and was the keystone to establishing this innovative invention. Throughout this paper, we will stress that the unique collaboration that facilitated the evolution of this technology is vital to the success of future developments in nanomedicine. PMID:20049813

Majoros, István J.; Williams, Christopher R.; Becker, Andrew; Baker, James R.



Azo polymeric hydrogels for colon targeted drug delivery.  


Azo polymeric hydrogels were developed for colon specific targeting. Methacryloyloxy azobenzene was synthesized and hydrogels were prepared by copolymerizing with hydroxyethyl methacrylate. These hydrogels were characterized by various spectral techniques such as Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. Equilibrium swelling measurements of the hydrogels were carried out in distilled water and also in simulated gastric and intestinal fluids. The in vitro release studies of the incorporated 5-flurouracil were carried out in simulated gastric and intestinal fluids. The in vitro release profiles of the drug were also obtained in the presence of azoreductase in the culture of intestinal flora. The release was faster and almost followed a zero order pattern. This can be attributed to the cleavage of the azo crosslinks in the hydrogel by the azoreductase and the release of the entrapped drug at the site of targeting i.e., colon. PMID:8573669

Shantha, K L; Ravichandran, P; Rao, K P



A new acivicin prodrug designed for tumor-Targeted delivery  

Microsoft Academic Search

Acivicin is an antitumor agent known to inhibit cell growth. A new prodrug 9b of acivicin 10 was synthesized, based on a p-hydroxybenzylcarbamate self-immolative spacer capable to release acivicin under esterase activity. The prodrug includes a maleimide-containing arm for linkage with thiol-containing macromolecules such as antibodies. This molecule is intended for the conception of bioconjugates to target an inactive acivicin

Christophe Antczak; Brigitte Bauvois; Claude Monneret; Jean-Claude Florent



Near-infrared-controlled, targeted hydrophobic drug-delivery system for synergistic cancer therapy.  


Hydrophobicity has been an obstacle that hinders the use of many anticancer drugs. A critical challenge for cancer therapy concerns the limited availability of effective biocompatible delivery systems for most hydrophobic therapeutic anticancer drugs. In this study, we have developed a targeted near-infrared (NIR)-regulated hydrophobic drug-delivery platform based on gold nanorods incorporated within a mesoporous silica framework (AuMPs). Upon application of NIR light, the photothermal effect of the gold nanorods leads to a rapid rise in the local temperature, thus resulting in the release of the entrapped drug molecules. By integrating chemotherapy and photothermotherapy into one system, we have studied the therapeutic effects of camptothecin-loaded AuMP-polyethylene glycol-folic acid nanocarrier. Results revealed a synergistic effect in vitro and in vivo, which would make it possible to enhance the therapeutic effect of hydrophobic drugs and decrease drug side effects. Studies have shown the feasibility of using this nanocarrier as a targeted and noninvasive remote-controlled hydrophobic drug-delivery system with high spatial/temperal resolution. Owing to these advantages, we envision that this NIR-controlled, targeted drug-delivery method would promote the development of high-performance hydrophobic anticancer drug-delivery system in future clinical applications. PMID:23765904

Yang, Xinjian; Liu, Zhen; Li, Zhenhua; Pu, Fang; Ren, Jinsong; Qu, Xiaogang



Tetanus toxin C fragment conjugated nanoparticles for targeted drug delivery to neurons  

PubMed Central

The use of nanoparticles for targeted drug delivery is often facilitated by specific conjugation of functional targeting molecules to the nanoparticle surface. We compared different biotin binding proteins (avidin, streptavidin, or neutravidin) as crosslinkers to conjugate proteins to biodegradable nanoparticles prepared from PLGA-PEG-biotin polymers. Avidin gave the highest levels of overall protein conjugation, whereas neutravidin minimized protein non-specific binding to the polymer. The tetanus toxin C fragment (TTC), which is efficiently retrogradely transported in neurons and binds to neurons with high specificity and affinity, retained the ability to bind to neuroblastoma cells following amine group modifications. TTC was conjugated to nanoparticles using neutravidin, and the resulting nanoparticles were shown to selectively target neuroblastoma cells in vitro. TTC-conjugated nanoparticles have the potential to serve as drug delivery vehicles targeted to the central nervous system. PMID:17854886

Townsend, Seth A.; Evrony, Gilad D.; Gu, Frank X.; Schulze, Martin P.; Brown, Robert H.; Langer, Robert S.



Transferrin receptor-targeted theranostic gold nanoparticles for photosensitizer delivery in brain tumors  

NASA Astrophysics Data System (ADS)

Therapeutic drug delivery across the blood-brain barrier (BBB) is not only inefficient, but also nonspecific to brain stroma. These are major limitations in the effective treatment of brain cancer. Transferrin peptide (Tfpep) targeted gold nanoparticles (Tfpep-Au NPs) loaded with the photodynamic pro-drug, Pc 4, have been designed and compared with untargeted Au NPs for delivery of the photosensitizer to brain cancer cell lines. In vitro studies of human glioma cancer lines (LN229 and U87) overexpressing the transferrin receptor (TfR) show a significant increase in cellular uptake for targeted conjugates as compared to untargeted particles. Pc 4 delivered from Tfpep-Au NPs clusters within vesicles after targeting with the Tfpep. Pc 4 continues to accumulate over a 4 hour period. Our work suggests that TfR-targeted Au NPs may have important therapeutic implications for delivering brain tumor therapies and/or providing a platform for noninvasive imaging.

Dixit, Suraj; Novak, Thomas; Miller, Kayla; Zhu, Yun; Kenney, Malcolm E.; Broome, Ann-Marie



Overcoming the stromal barrier for targeted delivery of HPMA copolymers to pancreatic tumors.  


Delivery of macromolecules to pancreatic cancer is inhibited by a dense extracellular matrix composed of hyaluronic acid, smooth muscle actin and collagen fibers. Hyaluronic acid causes a high intratumoral fluidic pressure which prevents diffusion and penetration into the pancreatic tumor. This study involves the breaking down of hyaluronic acid by treating CAPAN-1 xenograft tumors in athymic nu/nu mice with targeted N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers radiolabeled with (111)In for single photon emission computerized tomography (SPECT) imaging. Two targeting strategies were investigated including ?v?3 integrin and HER2 receptors. HPMA copolymers were targeted to these receptors by conjugating short peptide ligands cRGDfK and KCCYSL to the side chains of the copolymer. Results demonstrate that tumor targeting can be achieved in vivo after treatment with hyaluronidase. This approach shows promise for enhanced delivery of polymer-peptide conjugates to solid tumors. PMID:23933441

Buckway, Brandon; Wang, Yongjian; Ray, Abhijit; Ghandehari, Hamidreza



First line treatment of advanced non-small-cell lung cancer – specific focus on albumin bound paclitaxel  

PubMed Central

Lung cancer is the leading cause of cancer mortality worldwide in both men and women. Non-small-cell lung cancer (NSCLC) is the most common type of lung cancer, accounting for more than 80% of cases. Paclitaxel has a broad spectrum of activity against various malignancies, including NSCLC. Paclitaxel is poorly soluble in water and thus, until recently, its commercially available preparations contained a non-ionic solvent Cremophor EL®. Cremophor EL® improves the solubility of paclitaxel and allows its intravenous administration. However, certain side-effects associated with paclitaxel, such as hypersensitivity reactions, myelosuppression, and peripheral neuropathy, are known to be worsened by Cremophor®. Nanoparticle albumin-bound paclitaxel ([nab-paclitaxel] ABRAXANE® ABI-007) is a new generation formulation of paclitaxel that obviates the need for Cremophor®, resulting in a safer and faster infusion without requiring the use of premedications to avoid hypersensitivity. Albumin-binding receptor-mediated delivery and lack of sequestering Cremophor® micelles allow higher intratumoral concentration of pharmacologically active paclitaxel. Multiple clinical trials have demonstrated a superior tolerability profile of nab-paclitaxel in comparison to solvent-bound paclitaxel (sb-paclitaxel). A recent Phase III trial compared the effects of weekly nab-paclitaxel in combination with carboplatin versus sb-paclitaxel in combination with carboplatin given every 3 weeks for first line treatment of NSCLC. This trial highlights the weekly nab-paclitaxel combination as an alternate treatment option for NSCLC, with higher response rate in squamous cell NSCLC and longer survival in elderly patients. This review will focus on the properties of nab-paclitaxel and its use in the first line treatment of NSCLC. PMID:24399877

Gupta, Neha; Hatoum, Hassan; Dy, Grace K



Glycyrrhetinic acid-modified chitosan\\/poly(ethylene glycol) nanoparticles for liver-targeted delivery  

Microsoft Academic Search

A liver-targeted drug delivery carrier, composed of chitosan\\/poly(ethylene glycol)–glycyrrhetinic acid (CTS\\/PEG–GA) nanoparticles, was prepared by an ionic gelation process, in which glycyrrhetinic acid (GA) acted as the targeting ligand. The formation and characterization of these nanoparticles were confirmed by FT-IR, dynamic light scattering (DLS) and zeta potential measurements. The biodistribution of the nanoparticles was assessed by single-photon emission computed tomography

Qin Tian; Chuang-Nian Zhang; Xiu-Hua Wang; Wei Wang; Wei Huang; Rui-Tao Cha; Chun-Hong Wang; Zhi Yuan; Min Liu; Hai-Ying Wan; Hua Tang



Biomolecular corona on nanoparticles: a survey of recent literature and its implications in targeted drug delivery  

PubMed Central

Achieving controlled cellular responses of nanoparticles (NP) is critical for the successful development and translation of NP-based drug delivery systems. However, precise control over the physicochemical and biological properties of NPs could become convoluted, diminished, or completely lost as a result of the adsorption of biomolecules to their surfaces. Characterization of the formation of the “biomolecular” corona has thus received increased attention due to its impact on NP and protein structure as well as its negative effect on NP-based targeted drug delivery. This review presents a concise survey of the recent literature concerning the importance of the NP-biomolecule corona and how it can be utilized to improve the in vivo efficacy of targeted delivery systems. PMID:25506050

Pearson, Ryan M.; Juettner, Vanessa V.; Hong, Seungpyo



Chlorotoxin-conjugated graphene oxide for targeted delivery of an anticancer drug  

PubMed Central

Current chemotherapy for glioma is rarely satisfactory due to low therapeutic efficiency and systemic side effects. We have developed a glioma-targeted drug delivery system based on graphene oxide. Targeted peptide chlorotoxin-conjugated graphene oxide (CTX-GO) sheets were successfully synthesized and characterized. Doxorubicin was loaded onto CTX-GO (CTX-GO/DOX) with high efficiency (570 mg doxorubicin per gram CTX-GO) via noncovalent interactions. Doxorubicin release was pH-dependent and showed sustained-release properties. Cytotoxicity experiments demonstrated that CTX-GO/DOX mediated the highest rate of death of glioma cells compared with free doxorubicin or graphene oxide loaded with doxorubicin only. Further, conjugation with chlorotoxin enhanced accumulation of doxorubicin within glioma cells. These findings indicate that CTX-GO is a promising platform for drug delivery and provide a rationale for developing a glioma-specific drug delivery system. PMID:24672236

Wang, Hao; Gu, Wei; Xiao, Ning; Ye, Ling; Xu, Qunyuan



Targeted delivery of Epirubicin to cancer cells by PEGylated A10 aptamer.  


Clinical administrations of anthracyclines are limited by cardiotoxicity and myelosuppression. Targeted delivery of anticancer agents is especially important in reducing their side effects. In this work, A10 (Apt), an aptamer for prostate-specific membrane anytigen (PSMA), was applied for targeted delivery of Epirubicin (Epi) to LNCaP cells (PSMA(+)). Flow cytometry analysis showed that PEG-Apt-Epi complex was internalized effectively to LNCaP cells (PSMA(+)), but not to PC3 cells (PSMA(-)). This fact was confirmed by less cytotoxicity of PEG-Apt-Epi complex in PC3 cells in comparison with Epi alone. No significant change in viability between Epi- and complex-treated LNCaP cells was observed. In conclusion, PEG-Apt-Epi complex is an efficient and simple system for specific delivery of drug to PSMA-expressing cell lines. PMID:23815443

Taghdisi, Seyed Mohammad; Danesh, Noor Mohammad; Sarreshtehdar Emrani, Ahmad; Tabrizian, Kaveh; Zandkarimi, Majid; Ramezani, Mohammad; Abnous, Khalil



Targeting blood–brain barrier changes during inflammatory pain: an opportunity for optimizing CNS drug delivery  

PubMed Central

The blood–brain barrier (BBB) is the most significant obstacle to effective CNS drug delivery. It possesses structural and biochemical features (i.e., tight-junction protein complexes and, influx and efflux transporters) that restrict xenobiotic permeation. Pathophysiological stressors (i.e., peripheral inflammatory pain) can alter BBB tight junctions and transporters, which leads to drug-permeation changes. This is especially critical for opioids, which require precise CNS concentrations to be safe and effective analgesics. Recent studies have identified molecular targets (i.e., endogenous transporters and intracellular signaling systems) that can be exploited for optimization of CNS drug delivery. This article summarizes current knowledge in this area and emphasizes those targets that present the greatest opportunity for controlling drug permeation and/or drug transport across the BBB in an effort to achieve optimal CNS opioid delivery. PMID:22468221

Ronaldson, Patrick T; Davis, Thomas P



Magnetofection: enhancing and targeting gene delivery by magnetic force in vitro and in vivo  

Microsoft Academic Search

Low efficiencies of nonviral gene vectors, the receptor-dependent host tropism of adenoviral or low titers of retroviral vectors limit their utility in gene therapy. To overcome these deficiencies, we associated gene vectors with superparamagnetic nanoparticles and targeted gene delivery by application of a magnetic field. This potentiated the efficacy of any vector up to several hundred-fold, allowed reduction of the

F. Scherer; M. Anton; U. Schillinger; J. Henkel; C. Bergemann; A. Kruger; B. Gansbacher; C. Plank



Targeted delivery of chlorotoxin-modified DNA-loaded nanoparticles to glioma via intravenous administration  

Microsoft Academic Search

Gene therapy offers great potential for brain glioma. However, therapeutic genes could not reach glioma spontaneously. A glioma-targeting gene delivery system is highly desired to transfer exogenous genes throughout the tumor focus. In this study, the nanoscopic high-branching dendrimer, polyamidoamine (PAMAM), was selected as the main vector. Chlorotoxin (CTX), which has been demonstrated to bind specifically to receptor expressed in

Rongqin Huang; Weilun Ke; Liang Han; Jianfeng Li; Shuhuan Liu; Chen Jiang



Towards multifunctional, targeted drug delivery systems using mesoporous silica nanoparticles - opportunities & challenges  

NASA Astrophysics Data System (ADS)

One of the big challenges of medicine today is to deliver drugs specifically to defected cells. Nanoparticulate drug carriers have the potential to answer to this call, as nanoparticles can cross physiological barriers and access different tissues, and also be provided in a targetable form aimed at enhancing cell specificity of the carrier. Recent developments within material science and strong collaborative efforts crossing disciplinary borders have highlighted the potential of mesoporous silica nanoparticles (MSNs) for such targeted drug delivery. Here we outline recent advances which in this sense push MSNs to the forefront of drug delivery development. Relatively straightforward inside-out tuning of the vehicles, high flexibility, and potential for sophisticated release mechanisms make these nanostructures promising candidates for targeted drug delivery such as `smart' cancer therapies. Moreover, due to the large surface area and the controllable surface functionality of MSNs, they can be controllably loaded with large amounts of drugs and coupled to homing molecules to facilitate active targeting, simultaneously carrying traceable (fluorescent or magnetically active) modalities, also making them highly interesting as theragnostic agents. However, the increased relative surface area and small size, and flexible surface functionalization which is beneficially exploited in nanomedicine, consequently also includes potential risks in their interactions with biological systems. Therefore, we also discuss some safety issues regarding MSNs and highlight how different features of the drug delivery platform influence their behaviour in a biological setting. Addressing these burning questions will facilitate the application of MSNs in nanomedicine.

Rosenholm, Jessica M.; Sahlgren, Cecilia; Lindén, Mika




EPA Science Inventory

We present an in silico dosimetry model which can be used for inhalation toxicology (risk assessment of inhaled air pollutants) and aerosol therapy ( targeted delivery of inhaled drugs). This work presents scientific and clinical advances beyond the development of the original in...


Self-assembled hybrid nanoparticles for targeted co-delivery of two drugs into cancer cells.  


A therapeutic aptamer-lipid-poly(lactide-co-glycolic acid) hybrid nanoparticle-based drug delivery system was prepared and characterized. This system can co-deliver two different drugs with distinct solubility and different anticancer mechanisms to target cancer cells with high specificity and efficiency. PMID:24516863

Huang, Fujian; You, Mingxu; Chen, Tao; Zhu, Guizhi; Liang, Haojun; Tan, Weihong



Cell-specific aptamers and their conjugation with nanomaterials for targeted drug delivery.  


Introduction: Aptamers are short, single-stranded DNA or RNA sequences that can fold into complex secondary and tertiary structures and bind to various target molecules with high affinity and specificity. These properties, as well as rapid tissue penetration and ease of chemical modification, make aptamers ideal recognition elements for in vivo targeted drug delivery and attractive molecules for use in disease diagnosis and therapy. Areas covered: The general properties of aptamers as well as advantages over their counterpart antibodies are briefly discussed. Next, aptamer selection by cell- systematic evolution of ligands by exponential enrichment is described in detail. Finally, the review summarizes recent progress in the field of targeted drug delivery based on aptamers and their conjugation to liposomes, micelles and other nanomaterials. Expert opinion: Advances in nanotechnology have led to new and improved nanomaterials for biomedical applications. Conjugation of nanoparticles (NPs) with aptamers exploits both technologies, making aptamer-NP conjugates ideal agents for drug delivery with proven therapeutic effects and the reduction of toxicity to normal tissue. The use of multivalent aptamer-conjugated nanomaterials represents one of the new directions for drug development in the future; as such, continuing studies of these multivalent aptamers and bioconjugates should result in important clinical applications in targeted drug delivery. PMID:25430795

Liao, Jie; Liu, Bo; Liu, Jun; Zhang, Jiani; Chen, Ke; Liu, Huixia



Theranostic Nanoparticles Carrying Doxorubicin Attenuate Targeting Ligand Specific Antibody Responses Following Systemic Delivery  

PubMed Central

Understanding the effects of immune responses on targeted delivery of nanoparticles is important for clinical translations of new cancer imaging and therapeutic nanoparticles. In this study, we found that repeated administrations of magnetic iron oxide nanoparticles (IONPs) conjugated with mouse or human derived targeting ligands induced high levels of ligand specific antibody responses in normal and tumor bearing mice while injections of unconjugated mouse ligands were weakly immunogenic and induced a very low level of antibody response in mice. Mice that received intravenous injections of targeted and polyethylene glycol (PEG)-coated IONPs further increased the ligand specific antibody production due to differential uptake of PEG-coated nanoparticles by macrophages and dendritic cells. However, the production of ligand specific antibodies was markedly inhibited following systemic delivery of theranostic nanoparticles carrying a chemotherapy drug, doxorubicin. Targeted imaging and histological analysis revealed that lack of the ligand specific antibodies led to an increase in intratumoral delivery of targeted nanoparticles. Results of this study support the potential of further development of targeted theranostic nanoparticles for the treatment of human cancers. PMID:25553097

Yang, Emmy; Qian, Weiping; Cao, Zehong; Wang, Liya; Bozeman, Erica N.; Ward, Christina; Yang, Bin; Selvaraj, Periasamy; Lipowska, Malgorzata; Wang, Y. Andrew; Mao, Hui; Yang, Lily



Depth-targeted transvascular drug delivery by using annular-shaped photomechanical waves  

NASA Astrophysics Data System (ADS)

Laser-based drug delivery is attractive for the targeting capability due to high spatial controllability of laser energy. Recently, we found that photomechanical waves (PMWs) can transiently increase the permeability of blood vessels in skin, muscle and brain of rats. In this study, we examined the use of annular-shaped PMWs to increase pressure at target depths due to superposition effect of pressure waves. This can increase the permeability of blood vessels located in the specific depth regions, enabling depth-targeted transvascular drug delivery. Annular PMWs were produced by irradiating a laser-absorbing material with annular-shaped pulsed laser beams that were produced by using an axicon lens. We first examined propagation and pressure characteristics of annular PMWs in tissue phantoms and confirmed an increased pressure at a target depth, which can be controlled by changing laser parameters. We injected Evans blue (EB) into a rat tail vein, and annular PMWs (inner diameter, 3 mm; outer diameter, 5 mm) were applied from the myofascial surface of the anterior tibialis muscle. After perfusion fixation, we observed fluorescence originating from EB in the tissue. We observed intense fluorescence at a target depth region of around 5 mm. These results demonstrate the capability of annular PMWs for depth-targeted transvascular drug delivery.

Akiyama, Takuya; Sato, Shunichi; Ashida, Hiroshi; Terakawa, Mitsuhiro



Targeted Polymersome Delivery of siRNA Induces Cell Death of Breast Cancer Cells Dependent upon Orai3 Protein Expression  

E-print Network

Targeted Polymersome Delivery of siRNA Induces Cell Death of Breast Cancer Cells Dependent upon 55455, United States ABSTRACT: Polymersomes, polymeric vesicles that self-assemble in aqueous solutions. Past work has highlighted peptide- functionalized polymersomes as a highly promising targeted delivery

Kokkoli, Efie


Acoustic Molecular Imaging and Targeted Drug Delivery with Perfluorocarbon Nanoparticles  

NASA Astrophysics Data System (ADS)

Advances in molecular biology and cellular biochemistry are providing new opportunities for diagnostic medical imaging to "see" beyond the anatomical manifestations of disease to the earliest biochemical signatures of disease. Liquid perfluorocarbon nanoparticles provide inherent acoustic contrast when bound to targets, e.g., fibrin deposits in a thrombus, but unbound nanoparticles are undetectable. This nanoparticle platform may be further functionalized with paramagnetic metals, such as gadolinium, or radionuclides, with homing ligands, like anti-?v?3-integrins, and therapeutic agents. Acoustic imaging of densely distributed biomarkers, e.g., fibrin epitopes, is readily accommodated with fundamental imaging, but for sparse biomarkers, e.g., integrins, we have developed and implemented novel, nonlinear imaging techniques based upon information-theoretic receivers (i.e., thermodynamic receivers). These novel receivers allow sensitive direct imaging of contrast development.

Lanza, Gregory M.; Hughes, Michael. S.; Marsh, Jon N.; Scott, Michael J.; Zhang, Huiying; Lacy, Elizabeth K.; Allen, John S.; Wickline, Samuel A.



Paclitaxel Induces Apoptosis in Breast Cancer Cells through Different Calcium—Regulating Mechanisms Depending on External Calcium Conditions  

PubMed Central

Previously, we reported that endoplasmic reticulum calcium stores were a direct target for paclitaxel initiation of apoptosis. Furthermore, the actions of paclitaxel attenuated Bcl-2 resistance to apoptosis through endoplasmic reticulum-mediated calcium release. To better understand the calcium-regulated mechanisms of paclitaxel-induced apoptosis in breast cancer cells, we investigated the role of extracellular calcium, specifically; whether influx of extracellular calcium contributed to and/or was necessary for paclitaxel-induced apoptosis. Our results demonstrated that paclitaxel induced extracellular calcium influx. This mobilization of extracellular calcium contributed to subsequent cytosolic calcium elevation differently, depending on dosage. Under normal extracellular calcium conditions, high dose paclitaxel induced apoptosis-promoting calcium influx, which did not occur in calcium-free conditions. In the absence of extracellular calcium an “Enhanced Calcium Efflux” mechanism in which high dose paclitaxel stimulated calcium efflux immediately, leading to dramatic cytosolic calcium decrease, was observed. In the absence of extracellular calcium, high dose paclitaxel’s stimulatory effects on capacitative calcium entry and apoptosis could not be completely restored. Thus, normal extracellular calcium concentrations are critical for high dose paclitaxel-induced apoptosis. In contrast, low dose paclitaxel mirrored controls, indicating that it occurs independent of extracellular calcium. Thus, extracellular calcium conditions only affect efficacy of high dose paclitaxel-induced apoptosis. PMID:24549172

Pan, Zhi; Avila, Andrew; Gollahon, Lauren



Targeted delivery of carbon nanotubes to cancer cells  

NASA Astrophysics Data System (ADS)

CD22 is broadly expressed on human B cell lymphomas. Monoclonal anti-CD22 antibodies (MAbs) alone, or coupled to toxins, have been used to selectively target these tumors both in severe combined immunodeficient (SCID) mice with xenografted human lymphomas and in patients. Single-walled carbon nanotubes (CNTs) attached to antibodies or peptides represent another approach to targeting cancer cells. CNTs convert absorbed near-infrared (NIR) light into heat, which can thermally ablate cells in the vicinity of the CNTs. We have made MAb-CNT constructs where the MAb was either noncovalently or covalently coupled to CNTs, and investigated their ability to bind specifically to cells and to thermally ablate them after exposure to NIR light. The specific binding of these MAb-CNT constructs to antigen-positive and antigen-negative cells was demonstrated in vitro by using CD22+CD25 - Daudi cells, CD22-CD25+ phytohemagglutinin (PHA)-activated normal human peripheral blood mononuclear cells (PBMCs) and CNTs coupled non-covalently or covalently to either anti-CD22 or anti-CD25. We then demonstrated that the MAb-CNTs could bind to tumor cells expressing the relevant antigen but not to cells lacking the antigen. Furthermore we showed that, following exposure to NIR light, the cells could be thermally ablated. We also determined the stability of the MAb-CNTs in conditions designed to mimic the in vivo environment, i.e. mouse serum at 37°C. We then use the intrinsic Raman signature of CNTs to study the circulation and tissue distribution of intravenously injected MAb-CNTs in a murine xenograft model of lymphoma in vivo over a period of 24 hrs. We demonstrated that the MAb-CNTs have a short half-life in blood and that most of them are cleared by the reticuloendothelial system (RES). In the current embodiment, these constructs would therefore be of limited effectiveness in vivo.

Chakravarty, Pavitra


Synthesis of Doxorubicin loaded magnetic chitosan nanoparticles for pH responsive targeted drug delivery.  


Targeted drug delivery is a promising alternative to overcome the limitations of classical chemotherapy. In an ideal targeted drug delivery system carrier nanoparticles would be directed to the tumor tissue and selectively release therapeutic molecules. As a novel approach, chitosan coated magnetic nanoparticles (CS MNPs) maintain a pH dependent drug delivery which provides targeting of drugs to the tumor site under a magnetic field. Among various materials, chitosan has a great importance as a pH sensitive, natural, biodegradable, biocompatible and bioadhesive polymer. The aim of this study was to obtain an effective targeted delivery system for Doxorubicin, using chitosan coated MNPs. Different sized CS MNPs were produced by in situ synthesis method. The anti-cancer agent Doxorubicin was loaded onto CS MNPs which were characterized previously. Doxorubicin loading was confirmed by FTIR. Drug loading and release characteristics, and stability of the nanoparticles were investigated. Our results showed that the CS MNPs have pH responsive release characteristics. The cellular internalization of Doxorubicin loaded CS MNPs were visualized by fluorescent microscopy. Doxorubicin loaded CS MNPs are efficiently taken up by MCF-7 (MCF-7/S) and Doxorubicin resistant MCF-7 (MCF-7/1 ?M) breast cancer cells, which increases the efficacy of drug and also maintains overcoming the resistance of Doxorubicin in MCF-7/Dox cells. Consequently, CS MNPs synthesized at various sizes can be effectively used for the pH dependent release of Doxorubicin in cancer cells. Results of this study can provide new insights in the development of pH responsive targeted drug delivery systems to overcome the side effects of conventional chemotherapy. PMID:24931189

Unsoy, Gozde; Khodadust, Rouhollah; Yalcin, Serap; Mutlu, Pelin; Gunduz, Ufuk



Iron Oxide Nanoparticles as a Drug Delivery Vehicle for MRI Monitored Magnetic Targeting of Brain Tumors  

PubMed Central

This study explored the possibility of utilizing iron oxide nanoparticles as a drug delivery vehicle for minimally invasive, MRI-monitored magnetic targeting of brain tumors. In vitro determined hydrodynamic diameter of ~100nm, saturation magnetization of 94 emu/g Fe and T2 relaxivity of 43 s?1mM?1 of the nanoparticles suggested their applicability for this purpose. In vivo effect of magnetic targeting on the extent and selectivity of nanoparticle accumulation in tumors of rats harboring orthotopic 9L-gliosarcomas was quantified with MRI. Animals were intravenously injected with nanoparticles (12 mg Fe/kg) under a magnetic field density of 0 T (control) or 0.4 T (experimental) applied for 30 minutes. MR images were acquired prior to administration of nanoparticles and immediately after magnetic targeting at 1 hour intervals for 4 hours. Image analysis revealed that magnetic targeting induced a 5-fold increase in the total glioma exposure to magnetic nanoparticles over non-targeted tumors (p=0.005) and a 3.6-fold enhancement in the target selectivity index of nanoparticle accumulation in glioma over the normal brain (p=0.025). In conclusion, accumulation of iron oxide nanoparticles in gliosarcomas can be significantly enhanced by magnetic targeting and successfully quantified by MR imaging. Hence, these nanoparticles appear to be a promising vehicle for glioma-targeted drug delivery. PMID:17964647

Chertok, Beata; Moffat, Bradford A.; David, Allan E.; Yu, Faquan; Bergemann, Christian; Ross, Brian D.; Yang, Victor C.



Recent approaches of lipid-based delivery system for lymphatic targeting via oral route.  


Lymphatic system is a key target in research field due to its distinctive makeup and huge contributing functions within the body. Intestinal lymphatic drug transport (chylomicron pathway) is intensely described in research field till date because it is considered to be the best for improving oral drug delivery by avoiding first pass metabolism. The lymphatic imaging techniques and potential therapeutic candidates are engaged for evaluating disease states and overcoming these conditions. The novel drug delivery systems such as self-microemulsifying drug delivery system, nanoparticles, liposomes, nano-lipid carriers, solid lipid carriers are employed for delivering drugs through lymphatic system via various routes such as subcutaneous route, intraperitoneal route, pulmonary route, gastric sub-mucosal injection, intrapleural and intradermal. Among these colloidal particles, lipid-based delivery system is considered to be the best for lymphatic delivery. From the last few decades, mesenteric lymph duct cannulation and thoracic lymph duct cannulation are followed to assess lymphatic uptake of drugs. Due to their limitations, chylomicrons inhibitors and in-vitro models are employed, i.e. lipolysis model and permeability model. Currently, research on this topic still continues and drainage system used to deliver the drugs against lymphatic disease as well as targeting other organs by modulating the chylomicron pathway. PMID:25148607

Chaudhary, Shilpa; Garg, Tarun; Murthy, R S R; Rath, Goutam; Goyal, Amit K



Single-Antibody, Targeted Nanoparticle Delivery of Camptothecin  

PubMed Central

We have developed a new method for assembling targeted nanoparticles that utilizes the complexation between targeting agents that contain boronic acids and polymer-drug conjugates that possess diols. Here, we report the first in vivo, antitumor results of a nanoparticle formed via this new assembly methodology. A nanoparticle consisting of a mucic acid polymer conjugate of camptothecin (CPT), MAP-CPT; and containing on average one Herceptin antibody is investigated in nude mice bearing HER2 overexpressing BT-474 human breast cancer tumors. Nontargeted MAP-CPT and antibody-containing MAP-CPT nanoparticles of ca. 30–40 nm diameter and slightly negative zeta potential show prolonged in vivo circulation and similar biodistributions after intravenous tail vein injections in mice. The maximum tolerated dose (MTD) of the nontargeted and Herceptin-containing MAP-CPT nanoparticles are found to be 10 and 8 mg CPT/kg, respectively, in mice. Mice bearing BT-474 human breast tumors treated with nontargeted MAP-CPT nanoparticles at 8 mg CPT/kg show significant tumor growth inhibition (mean tumor volume of 63 mm3) when compared to Irinotecan at 80 mg/kg (mean tumor volume of 575 mm3) and CPT at 8 mg/kg (mean tumor volume of 808 mm3) at the end of the study. Herceptin antibody treatment at 5.9 mg/kg results in complete tumor regressions in 5 out of 8 mice, with a mean tumor volume of 60 mm3 at the end of the study. Mice treated with MAP-CPT nanoparticles at 1 mg CPT/kg do not show tumor inhibition. However, all mice receiving administrations of MAP-CPT nanoparticles (1 mg CPT/kg) that contain on average a single Herceptin molecule per nanoparticle (5.9 mg Herceptin equivalent/kg) show complete tumor regression by the end of the study. These results demonstrate that the antitumor efficacy of nanoparticles carrying anticancer drugs can be enhanced by incorporating on average a single antibody. PMID:23676007

Han, Han; Davis, Mark E.



A doxorubicin delivery platform using engineered natural membrane vesicle exosomes for targeted tumor therapy.  


Targeted drug delivery vehicles with low immunogenicity and toxicity are needed for cancer therapy. Here we show that exosomes, endogenous nano-sized membrane vesicles secreted by most cell types, can deliver chemotherapeutics such as doxorubicin (Dox) to tumor tissue in BALB/c nude mice. To reduce immunogenicity and toxicity, mouse immature dendritic cells (imDCs) were used for exosome production. Tumor targeting was facilitated by engineering the imDCs to express a well-characterized exosomal membrane protein (Lamp2b) fused to ?v integrin-specific iRGD peptide (CRGDKGPDC). Purified exosomes from imDCs were loaded with Dox via electroporation, with an encapsulation efficiency of up to 20%. iRGD exosomes showed highly efficient targeting and Dox delivery to ?v integrin-positive breast cancer cells in vitro as demonstrated by confocal imaging and flow cytometry. Intravenously injected targeted exosomes delivered Dox specifically to tumor tissues, leading to inhibition of tumor growth without overt toxicity. Our results suggest that exosomes modified by targeting ligands can be used therapeutically for the delivery of Dox to tumors, thus having great potential value for clinical applications. PMID:24345736

Tian, Yanhua; Li, Suping; Song, Jian; Ji, Tianjiao; Zhu, Motao; Anderson, Gregory J; Wei, Jingyan; Nie, Guangjun



Targeted Delivery of Doxorubicin Using a Colorectal Cancer-Specific ssDNA Aptamer.  


Targeted drug delivery is particularly important in cancer treatment because many antitumor drugs are nonspecific and highly toxic to both cancerous and normal cells. The L33 aptamer is a single-stranded DNA (ssDNA) sequence that has the ability to recognize human colorectal cancer (CRC) cell line HCT116 specifically. In this study, we demonstrated that the L33 aptamer can selectively internalize into target HCT116 cells via receptor-mediated endocytosis. Based on this finding, we developed an aptamer-based drug delivery system using L33 as the carrier of the antitumor drug doxorubicin (Dox). The L33-Dox complex exhibited specific and high affinity (Kd ?=?14.3?±?2.2 nM) binding to HCT116 cells. The results of cytotoxicity assays revealed that the L33-Dox complex was capable of selectively delivering the drug to the target HCT116 cells and lowered the toxicity for nontarget CL187 cells. These findings indicate that the aptamer-based targeted drug delivery system has the potential to be used in clinical settings and may overcome drug resistance to a certain extent because high drug dosages can be directed toward target cells. Anat Rec, 297:2280-2288, 2014. © 2014 Wiley Periodicals, Inc. PMID:25044297

Li, Wanming; Chen, Hang; Yu, Min; Fang, Jin



Nanomaterials for targeted drug delivery to cancer stem cells.  


Recent developments in cancer biology have identified the existence of a sub-poplulation of cells - cancer stem cells (CSC) that are resistant to most traditional therapies (e.g. chemotherapy and radiotherapy) and have the ability to repair their damaged DNA. These findings have necessitated a break with traditional oncology management and encouraged new perspectives concerning cancer treatment. Understanding the functional biology of CSCs - especially the signaling pathways that are involved in their self-renewal mechanisms - is crucial for discovering new forms of treatment. In this review, we highlight current and future prospects for potential cancer therapies based on the use of nano-sized materials. Nanomaterials could revolutionize cancer management because of their distinctive features - unique surface chemistry, strong electronic, optic, and magnetic properties - that are found neither in bulk materials nor in single molecules. Based on these distinct properties, we believe that nanomaterials could be excellent candidates for use in CSC research in order to optimize cancer therapeutics. Moreover, we propose these nanomaterials for the inhibition of the self-renewal pathways of CSCs by focusing on the Hedgehog, Notch, and Wnt/?-catenin self-renewal mechanisms. By introducing these methods for the detection, targeting, and destruction of CSCs, an efficient alternative treatment for the incurable disease of cancer could be provided. PMID:24697156

Orza, Anamaria; Casciano, Daniel; Biris, Alexandru



Recent advances in lymphatic targeted drug delivery system for tumor metastasis  

PubMed Central

The lymphatic system has an important defensive role in the human body. The metastasis of most tumors initially spreads through the surrounding lymphatic tissue and eventually forms lymphatic metastatic tumors; the tumor cells may even transfer to other organs to form other types of tumors. Clinically, lymphatic metastatic tumors develop rapidly. Given the limitations of surgical resection and the low effectiveness of radiotherapy and chemotherapy, the treatment of lymphatic metastatic tumors remains a great challenge. Lymph node metastasis may lead to the further spread of tumors and may be predictive of the endpoint event. Under these circumstances, novel and effective lymphatic targeted drug delivery systems have been explored to improve the specificity of anticancer drugs to tumor cells in lymph nodes. In this review, we summarize the principles of lymphatic targeted drug delivery and discuss recent advances in the development of lymphatic targeted carriers. PMID:25610710

Zhang, Xiao-Yu; Lu, Wei-Yue



Bioresponsive hyaluronic acid-capped mesoporous silica nanoparticles for targeted drug delivery.  


In this paper, we present a facile strategy to synthesize hyaluronic acid (HA) conjugated mesoporous silica nanoparticles (MSP) for targeted enzyme responsive drug delivery, in which the anchored HA polysaccharides not only act as capping agents but also as targeting ligands without the need of additional modification. The nanoconjugates possess many attractive features including chemical simplicity, high colloidal stability, good biocompatibility, cell-targeting ability, and precise cargo release, making them promising agents for biomedical applications. As a proof-of-concept demonstration, the nanoconjugates are shown to release cargoes from the interior pores of MSPs upon HA degradation in response to hyaluronidase-1 (Hyal-1). Moreover, after receptor-mediated endocytosis into cancer cells, the anchored HA was degraded into small fragments, facilitating the release of drugs to kill the cancer cells. Overall, we envision that this system might open the door to a new generation of carrier system for site-selective, controlled-release delivery of anticancer drugs. PMID:23303570

Chen, Zhaowei; Li, Zhenhua; Lin, Youhui; Yin, Meili; Ren, Jinsong; Qu, Xiaogang



Recent advances in lymphatic targeted drug delivery system for tumor metastasis.  


The lymphatic system has an important defensive role in the human body. The metastasis of most tumors initially spreads through the surrounding lymphatic tissue and eventually forms lymphatic metastatic tumors; the tumor cells may even transfer to other organs to form other types of tumors. Clinically, lymphatic metastatic tumors develop rapidly. Given the limitations of surgical resection and the low effectiveness of radiotherapy and chemotherapy, the treatment of lymphatic metastatic tumors remains a great challenge. Lymph node metastasis may lead to the further spread of tumors and may be predictive of the endpoint event. Under these circumstances, novel and effective lymphatic targeted drug delivery systems have been explored to improve the specificity of anticancer drugs to tumor cells in lymph nodes. In this review, we summarize the principles of lymphatic targeted drug delivery and discuss recent advances in the development of lymphatic targeted carriers. PMID:25610710

Zhang, Xiao-Yu; Lu, Wei-Yue



Targeted delivery of EV peptide to tumor cell cytoplasm using lipid coated calcium carbonate nanoparticles.  


Intracellular-acting peptide drugs are effective for inhibiting cytoplasmic protein targets, yet face challenges with penetrating the cancer cell membrane. We have developed a lipid nanoparticle formulation that utilizes a pH-sensitive calcium carbonate complexation mechanism to enable the targeted delivery of the intracellular-acting therapeutic peptide EEEEpYFELV (EV) into lung cancer cells. Lipid-calcium-carbonate (LCC) nanoparticles were conjugated with anisamide, a targeting ligand for the sigma receptor which is expressed on lung cancer cells. LCC EV nanoparticle treatment provoked severe apoptotic effects in H460 non-small cell lung cancer cells in vitro. LCC NPs also mediated the specific delivery of Alexa-488-EV peptide to tumor tissue in vivo, provoking a high tumor growth retardation effect with minimal uptake by external organs and no toxic effects. PMID:22796364

Kim, Sang Kyoon; Foote, Michael B; Huang, Leaf



Targeted in vivo delivery of siRNA and an endosome-releasing agent to hepatocytes.  


The discoveries of RNA interference (RNAi) and short interfering RNAs (siRNAs) have provided the opportunity to treat diseases in a fundamentally new way: by co-opting a natural process to inhibit gene expression at the mRNA level. Given that siRNAs must interact with the cells' natural RNAi machinery in order to exert their silencing effect, one of the most fundamental requirements for their use is efficient delivery to the desired cell type and, specifically, into the cytoplasm of those cells. Numerous research efforts involving the testing of a large number of delivery approaches using various carrier molecules and inventing several distinct formulation technologies during the past decade illustrate the difficulty and complexity of this task. We have developed synthetic polymer formulations for in vivo siRNA delivery named Dynamic PolyConjugates™ (DPCs) that are designed to mimic the features viruses possess for efficient delivery of their nucleic acids. These include small size, long half-life in circulation, capability of displaying distinct host cell tropism, efficient receptor binding and cell entry, disassembly in the endosome and subsequent release of the nucleic acid cargo to the cytoplasm. Here we present an example of this delivery platform composed of a hepatocyte-targeted endosome-releasing agent and a cholesterol-conjugated siRNA (chol-siRNA). This delivery platform forms the basis of ARC-520, an siRNA-based therapeutic for the treatment of chronic hepatitis B virus (HBV) infection. In this chapter, we provide a general overview of the steps in developing ARC-520 and detailed protocols for two critical stages of the discovery process: (1) verifying targeted in vivo delivery to hepatocytes and (2) evaluating in vivo drug efficacy using a mouse model of chronic HBV infection. PMID:25319651

Sebestyén, Magdolna G; Wong, So C; Trubetskoy, Vladimir; Lewis, David L; Wooddell, Christine I



Tumor cell-targeted delivery of nanoconjugated oligonucleotides in composite spheroids.  


Standard tissue culture has often been a poor model for predicting the efficacy of anti-cancer agents including oligonucleotides. In contrast to the simplicity of monolayer tissue cultures, a tumor mass includes tightly packed tumor cells, tortuous blood vessels, high levels of extracellular matrix, and stromal cells that support the tumor. These complexities pose a challenge for delivering therapeutic agents throughout the tumor, with many drugs limited to cells proximal to the vasculature. Multicellular tumor spheroids are superior to traditional monolayer cell culture for the assessment of cancer drug delivery, since they possess many of the characteristics of metastatic tumor foci. However, homogeneous spheroids comprised solely of tumor cells do not account for some of the key aspects of metastatic tumors, particularly the interaction with host cells such as fibroblasts. Further, homogeneous culture does not allow for the assessment of targeted delivery to tumor versus host cells. Here we have evaluated delivery of targeted and untargeted oligonucleotide nanoconjugates and of oligonucleotide polyplexes in both homogeneous and composite tumor spheroids. We find that inclusion of fibroblasts in the spheroids reduces delivery efficacy of the polyplexes. In contrast, targeted multivalent RGD-oligonucleotide nanoconjugates were able to effectively discriminate between melanoma cells and fibroblasts, thus providing tumor-selective uptake and pharmacological effects. PMID:25238564

Carver, Kyle; Ming, Xin; Juliano, Rudy L



Targeted drug-delivery approaches by nanoparticulate carriers in the therapy of inflammatory diseases  

PubMed Central

Limitations in therapy induced by adverse effects due to unselective drug availability and therefore the use of potentially too high doses are a common problem. One prominent example for this dilemma are inflammatory diseases. Colloidal carriers allow one to improve delivery of drugs to the site of action and appear promising to overcome this general therapeutic drawback. Specific uptake of nanoparticles by immune-related cells in inflamed barriers offers selective drug targeting to the inflamed tissue. Here we focus on nanocarrier-based drug delivery strategies for the treatment of common inflammatory disorders like rheumatoid arthritis, multiple sclerosis, uveitis or inflammatory bowel disease. PMID:19940000

Ulbrich, Wiebke; Lamprecht, Alf



Surface proteomic analysis of osteosarcoma identifies EPHA2 as receptor for targeted drug delivery  

PubMed Central

Background: Osteosarcoma (OS) is the most common bone tumour in children and adolescents. Despite aggressive therapy regimens, treatment outcomes are unsatisfactory. Targeted delivery of drugs can provide higher effective doses at the site of the tumour, ultimately improving the efficacy of existing therapy. Identification of suitable receptors for drug targeting is an essential step in the design of targeted therapy for OS. Methods: We conducted a comparative analysis of the surface proteome of human OS cells and osteoblasts using cell surface biotinylation combined with nano-liquid chromatography – tandem mass spectrometry-based proteomics to identify surface proteins specifically upregulated on OS cells. This approach generated an extensive data set from which we selected a candidate to study for its suitability as receptor for targeted treatment delivery to OS. First, surface expression of the ephrin type-A receptor 2 (EPHA2) receptor was confirmed using FACS analysis. Ephrin type-A receptor 2 expression in human tumour tissue was tested using immunohistochemistry. Receptor targeting and internalisation studies were conducted to assess intracellular uptake of targeted modalities via EPHA2. Finally, tissue micro arrays containing cores of human OS tissue were stained using immunohistochemistry and EPHA2 staining was correlated to clinical outcome measures. Results: Using mass spectrometry, a total of 2841 proteins were identified of which 156 were surface proteins significantly upregulated on OS cells compared with human primary osteoblasts. Ephrin type-A receptor 2 was highly upregulated and the most abundant surface protein on OS cells. In addition, EPHA2 was expressed in a vast majority of human OS samples. Ephrin type-A receptor 2 effectively mediates internalisation of targeted adenoviral vectors into OS cells. Patients with EPHA2-positive tumours showed a trend toward inferior overall survival. Conclusion: The results presented here suggest that the EPHA2 receptor can be considered an attractive candidate receptor for targeted delivery of therapeutics to OS. PMID:24064975

PosthumaDeBoer, J; Piersma, S R; Pham, T V; van Egmond, P W; Knol, J C; Cleton-Jansen, A M; van Geer, M A; van Beusechem, V W; Kaspers, G J L; van Royen, B J; Jiménez, C R; Helder, M N



A unique paclitaxel-mediated modulation of the catalytic activity of topoisomerase IIalpha.  


Paclitaxel (Taxol) is known to act by polymerizing and stabilizing microtubules. In spite of a known target, the existence of additional targets is suggested by a poor understanding of the mechanism(s) underlying eventual cell death by paclitaxel and by the drug's high efficacy, as compared to other spindle poisons. Based on the enhanced sensitivity of a mutant DNA double-strand break repair-deficient Chinese hamster ovary cell line to paclitaxel as well as to various topoisomerase (Topo) II poisons, it was hypothesized that paclitaxel, in addition to having an effect on microtubules, may also alter the activity of Topo II. This study demonstrates the unique, in vitro effects of paclitaxel on Topo II activity as investigated by monitoring the decatenation of kinetoplast DNA and relaxation of supercoiled plasmid DNA by Topo II. Unlike classical anti-topoisomerase drugs, low concentrations of paclitaxel (0.02-500 nM) stimulated Topo II catalytic activity, while higher concentrations over 5 microM inhibited the activity of Topo II. Furthermore, these effects of paclitaxel appear to be mediated through a direct interaction of paclitaxel with Topo II rather than an interaction with DNA or DNA-Topo II complexes. Collectively, the evidence presented suggests the existence of an atypical interaction between Topo II and paclitaxel that may disrupt the normal functioning of the enzyme. PMID:10378675

Dhawan, V; Swaffar, D S



Molecular design and nanoparticle-mediated intracellular delivery of functional proteins to target cellular pathways  

NASA Astrophysics Data System (ADS)

Intracellular delivery of specific proteins and peptides represents a novel method to influence stem cells for gain-of-function and loss-of-function. Signaling control is vital in stem cells, wherein intricate control of and interplay among critical pathways directs the fate of these cells into either self-renewal or differentiation. The most common route to manipulate cellular function involves the introduction of genetic material such as full-length genes and shRNA into the cell to generate (or prevent formation of) the target protein, and thereby ultimately alter cell function. However, viral-mediated gene delivery may result in relatively slow expression of proteins and prevalence of oncogene insertion into the cell, which can alter cell function in an unpredictable fashion, and non-viral delivery may lead to low efficiency of genetic delivery. For example, the latter case plagues the generation of induced pluripotent stem cells (iPSCs) and hinders their use for in vivo applications. Alternatively, introducing proteins into cells that specifically recognize and influence target proteins, can result in immediate deactivation or activation of key signaling pathways within the cell. In this work, we demonstrate the cellular delivery of functional proteins attached to hydrophobically modified silica (SiNP) nanoparticles to manipulate specifically targeted cell signaling proteins. In the Wnt signaling pathway, we have targeted the phosphorylation activity of glycogen synthase kinase-3beta (GSK-3beta) by designing a chimeric protein and delivering it in neural stem cells. Confocal imaging indicates that the SiNP-chimeric protein conjugates were efficiently delivered to the cytosol of human embryonic kidney cells and rat neural stem cells, presumably via endocytosis. This uptake impacted the Wnt signaling cascade, indicated by the elevation of beta-catenin levels, and increased transcription of Wnt target genes, such as c-MYC. The results presented here suggest that functional proteins can be delivered intracellularly in vitro using nanoparticles and used to target key signaling proteins and regulate cell signaling pathways. The same concept of naturally occurring protein-protein interactions can also be implemented to selectively bring intracellular protein targets in close proximity to proteasomal degradation machinery in cells and effect their depletion from the cellular compartments. This approach will be able to not only target entire pool of proteins to ubiquitination-mediated degradation, but also to specific sub-pools of posttranslationally modified proteins in the cell, provided peptides having distinct binding affinities are identified for posttranslational modifications. This system can then be tested for intracellular protein delivery using nanoparticle carriers to identify roles of different posttranslational modifications on the protein's activity. In future work, we propose to develop a cellular detection system, based on GFP complementation, which can be used to evaluate the efficiency of different protein delivery carriers to internalize proteins into the cell cytosol. We envision the application of nanoscale materials as intracellular protein delivery vehicles to target diverse cell signaling pathways at the posttranslational level, and subsequent metabolic manipulation, which may have interesting therapeutic properties and can potentially target stem cell fate.

Shah, Dhiral Ashwin


Targeted drug delivery into reversibly injured myocardium with silica nanoparticles: surface functionalization, natural biodistribution, and acute toxicity  

PubMed Central

The clinical outcome of patients with ischemic heart disease can be significantly improved with the implementation of targeted drug delivery into the ischemic myocardium. In this paper, we present our original findings relevant to the problem of therapeutic heart targeting with use of nanoparticles. Experimental approaches included fabrication of carbon and silica nanoparticles, their characterization and surface modification. The acute hemodynamic effects of nanoparticle formulation as well as nanoparticle biodistribution were studied in male Wistar rats. Carbon and silica nanoparticles are nontoxic materials that can be used as carriers for heart-targeted drug delivery. Concepts of passive and active targeting can be applied to the development of targeted drug delivery to the ischemic myocardial cells. Provided that ischemic heart-targeted drug delivery can be proved to be safe and efficient, the results of this research may contribute to the development of new technologies in the pharmaceutical industry. PMID:20463939

Galagudza, Michael M; Korolev, Dmitry V; Sonin, Dmitry L; Postnov, Viktor N; Papayan, Garry V; Uskov, Ivan S; Belozertseva, Anastasia V; Shlyakhto, Eugene V



Glycoprotein CD98 as a receptor for colitis-targeted delivery of nanoparticle.  


Treatment strategies for inflammatory bowel disease have been constrained by limited therapeutic efficacy and serious adverse effects owing to a lack of receptor for targeted drug delivery to the inflamed colon. Upon inflammation, CD98 expression is highly elevated in colonic epithelial cells and infiltrating immune cells. To investigate whether CD98 can be used as a colitis-targeted delivery receptor, we constructed CD98 Fab'-bearing quantum dots (QDs)-loaded nanoparticles (Fab'-NPs). The resultant Fab'-NPs had desired particle size (~458 nm) with a narrow size distribution and zeta-potential (approximately +19 mV), low cytotoxicity, and excellent fluorescence properties. Electron microscopy images provided direct evidence for the well-dispersed distribution of QDs within spherical Fab'-NPs. Cellular uptake experiments demonstrated that Fab'-NPs were efficiently internalized into Colon-26 and RAW 264.7 cells through the CD98-mediated endocytosis pathway, and showed that the targeting effect of CD98 Fab' markedly increased their cellular uptake efficiency compared with control pegylated QDs-loaded NPs (PEG-NPs). Furthermore, ex vivo studies showed much more effective accumulation of Fab'-NPs in colitis tissue than that of PEG-NPs. These findings suggest that because of inflammation-dependent over-expression of CD98, active colitis-targeted delivery can be accomplished using NPs decorated with CD98 antibody. PMID:24729869

Xiao, Bo; Yang, Yang; Viennois, Emilie; Zhang, Yuchen; Ayyadurai, Saravanan; Baker, Mark; Laroui, Hamed; Merlin, Didier




PubMed Central

Intrinsically echogenic liposomes (ELIP) can be adapted to encapsulate nitric oxide to facilitate ultrasound-enhanced delivery of therapeutic agents to atherosclerotic plaques. However, the NO loading of targeted ELIP caused a 93% decrease of antibody (Ab) immunoreactivity. The following hypothesis was tested: biotin/avidin-mediated coupling of NO-ELIP and Ab-conjugated ELIP will enable co-delivery of bioactive gases and ELIP that can encapsulate other agents without loss of targeting efficiency. Complex formation was initiated by addition of excess streptavidin to equal proportions of biotinylated Ab-ELIP and NO-ELIP. Fluorescence deconvolution microscopy, Coulter Multisizer 3 analysis and flow cytometry demonstrated that the ELIP coupling procedure formed mixed aggregates of ?10 liposomes within 1 minute. Intravascular ultrasound imaging and ELISA showed that echogenicity and targeting efficiency were completely and 69–99% retained, respectively. When complexed to NO-ELIP, ELIP bifunctionally targeted to both CD34 and ICAM-1 (BF-ELIP) increased human mononuclear cell migration through human coronary artery endothelial cell monolayers in transwell plates 4-fold relative to a nonspecific IgG-ELIP control and 2-fold relative to BF-ELIP alone. It was concluded that this novel multi-functional conjugation methodology provides a platform technology for site-specific co-delivery of bioactive gases and other agents. PMID:19903503

Klegerman, Melvin E.; Wassler, Michael; Huang, Shao-Ling; Zou, Yuejiao; Kim, Hyunggun; Shelat, Harnath S.; Holland, Christy K.; Geng, Yong-Jian; McPherson, David D.



Targeted drug delivery for cancer therapy: the other side of antibodies  

PubMed Central

Therapeutic monoclonal antibody (TMA) based therapies for cancer have advanced significantly over the past two decades both in their molecular sophistication and clinical efficacy. Initial development efforts focused mainly on humanizing the antibody protein to overcome problems of immunogenicity and on expanding of the target antigen repertoire. In parallel to naked TMAs, antibody-drug conjugates (ADCs) have been developed for targeted delivery of potent anti-cancer drugs with the aim of bypassing the morbidity common to conventional chemotherapy. This paper first presents a review of TMAs and ADCs approved for clinical use by the FDA and those in development, focusing on hematological malignancies. Despite advances in these areas, both TMAs and ADCs still carry limitations and we highlight the more important ones including cancer cell specificity, conjugation chemistry, tumor penetration, product heterogeneity and manufacturing issues. In view of the recognized importance of targeted drug delivery strategies for cancer therapy, we discuss the advantages of alternative drug carriers and where these should be applied, focusing on peptide-drug conjugates (PDCs), particularly those discovered through combinatorial peptide libraries. By defining the advantages and disadvantages of naked TMAs, ADCs and PDCs it should be possible to develop a more rational approach to the application of targeted drug delivery strategies in different situations and ultimately, to a broader basket of more effective therapies for cancer patients. PMID:23140144



Folate-polyethylene glycol conjugated carboxymethyl chitosan for tumor-targeted delivery of 5-fluorouracil.  


Targeted drug delivery has been evolving at an increasing rate due to its potential to reduce the minimum effective dose of a drug and its accompanying side effects. It has shown improved therapeutic efficacy at equivalent plasma concentrations; however, the development of effective targeted delivery systems has remained a major task. In this study, a drug carrier was designed and synthesized by conjugation of folate acid (FA) to carboxymethyl chitosan (CMCS) through a polyethylene glycol (PEG) spacer. The resulting conjugates were confirmed by 1H nuclear magnetic resonance and infrared spectroscopy. The cytotoxicity of CMCS and CMCS?5?fluorouracil (5?FU) was determined by a crystal violet stain assay. The potential of CMCS?PEG?FA for use in the targeted delivery of 5?FU was investigated using 3?(4,5?dimethylthiazol?2?yl)?2,5?diphenyltetrazolium bromide analysis in two cell lines, HeLa and A549, which contain different numbers of folate receptors on their surfaces. The MTT results revealed that in HeLa cells, the cytotoxicity of (CMCS?5?FU)?PEG?FU cells is greater compared with CMCS?5?FU, suggesting that folate receptor?mediated endocytosis may affect the cellular uptake efficiency of 5?FU?loaded CMCS?PEG?FA. The CMCS?PEG?FA conjugates presented in this study show promise as carriers for chemotherapeutic agents due to their solubility at physiological pH, efficiency in carrying chemotherapeutic agents, low cytotoxicity and targeting ability. PMID:24469407

Li, Hai-Lang; He, Ya-Xing; Gao, Qian-Hong; Wu, Guo-Zhong



Cell-mediated Delivery and Targeted Erosion of Vascular Endothelial Growth Factor-Crosslinked Hydrogelsa  

PubMed Central

We have previously reported a novel polymeric delivery vehicle that is assembled via interaction between heparin and the vascular endothelial growth factor (VEGF). Here, the cell-responsiveness of this hydrogel — including the delivery of VEGF in response to VEGFR-2 overexpressing PAE/KDR cells (porcine aortic endothelial cells (PAE) equipped with the transcript for the kinase insert domain receptor (KDR)), consequent erosion of the hydrogel matrix, and cellular response — are highlighted. The release of VEGF and hydrogel erosion reached 100% only in the presence of PAE/KDR. The [PEG-LMWH/VEGF] hydrogel (PEG = poly(ethylene glycol), LMWH = low molecular weight heparin) correspondingly prompted increases in VEGFR-2 phosphorylation and proliferation of PAE/KDR cells. This study proves that growth factor-crosslinked hydrogels can liberate VEGF in response to specific receptors, causing gel erosion and desired cell responses. The promise of these approaches in therapeutic applications, including targeted delivery, is suggested. PMID:21567519

Kim, Sung Hye; Kiick, Kristi L.



Targeted electro-delivery of oligonucleotides for RNA interference: siRNA and antimiR.  


For more than a decade, the understanding of RNA interference (RNAi) has been a growing field of interest. Micro-RNAs (miRNAs) are small regulatory RNAs that play an important role in disease development and progression and therefore represent a potential new class of therapeutic targets. However, delivery of RNAi-based oligonucleotides is one of the most challenging hurdles to RNAi-based drug development. Electropermeabilization (EP) is recognized as a successful non-viral method to transfer nucleic acids into living cells both in vitro and in vivo. EP is the direct application of electric pulses to cells or tissues that transiently permeabilize plasma membranes, allowing the efficient delivery of exogenous molecules. The present review focused on the mechanism of RNAi-based oligonucleotides electrotransfer, from cellular uptake to intracellular distribution. Biophysical theories on oligonucleotide electrotransfer will be also presented. The advantages and few drawbacks of EP-mediated delivery will also be discussed. PMID:24819217

Chabot, Sophie; Teissié, Justin; Golzio, Muriel



Targeted magnetic delivery and tracking of cells using a magnetic resonance imaging system.  


The success of cell therapies depends on the ability to deliver the cells to the site of injury. Targeted magnetic cell delivery is an emergent technique for localised cell transplantation therapy. The use of permanent magnets limits such a treatment to organs close to the body surface or an implanted magnetic source. A possible alternative method for magnetic cell delivery is magnetic resonance targeting (MRT), which uses magnetic field gradients inherent to all magnetic resonance imaging system, to steer ferromagnetic particles to their target region. In this study we have assessed the feasibility of such an approach for cell targeting, using a range of flow rates and different super paramagnetic iron oxide particles in a vascular bifurcation phantom. Using MRT we have demonstrated that 75% of labelled cells could be guided within the vascular bifurcation. Furthermore we have demonstrated the ability to image the labelled cells before and after magnetic targeting, which may enable interactive manipulation and assessment of the distribution of cellular therapy. This is the first demonstration of cellular MRT and these initial findings support the potential value of MRT for improved targeting of intravascular cell therapies. PMID:20382425

Riegler, Johannes; Wells, Jack A; Kyrtatos, Panagiotis G; Price, Anthony N; Pankhurst, Quentin A; Lythgoe, Mark F



Apoptosis induced by paclitaxel-loaded copolymer PLA–TPGS in Hep-G2 cells  

NASA Astrophysics Data System (ADS)

Paclitaxel is an important anticancer drug in clinical use for treatment of a variety of cancers. The clinical application of paclitaxel in cancer treatment is considerably limited due to its serious poor delivery characteristics. In this study paclitaxel-loaded copolymer poly(lactide)–d-?-tocopheryl polyethylene glycol 1000 succinate (PLA–TPGS) nanoparticles were prepared by a modified solvent extraction/evaporation technique. The characteristics of the nanoparticles, such as surface morphology, size distribution, zeta potential, solubility and apoptosis were investigated in vitro. The obtained spherical nanoparticles were negatively charged with a zeta potential of about ?18 mV with the size around 44 nm and a narrow size distribution. The ability of paclitaxel-loaded PLA–TPGS nanoparticles to induce apoptosis in human hepatocellular carcinoma cell line (Hep-G2) indicates the possibility of developing paclitaxel nanoparticles as a potential universal cancer chemotherapeutic agent.

Nguyen, Hoai Nam; Tran Thi, Hong Ha; Le Quang, Duong; Nguyen Thi, Toan; Tran Thi, Nhu Hang; Huong Le, Mai; Thu Ha, Phuong



Surface-Engineered Targeted PPI Dendrimer for Efficient Intracellular and Intratumoral siRNA Delivery  

PubMed Central

Low penetration ability of Small Interfering RNA (siRNA) through the cellular plasma membrane combined with its limited stability in blood, limits the effectiveness of the systemic delivery of siRNA. In order to overcome such difficulties, we constructed a nanocarrier-based delivery system by taking advantage of the lessons learned from the problems in the delivery of DNA. In the present study, siRNA nanoparticles were first formulated with Poly(Propyleneimine) (PPI) dendrimers. To provide lateral and steric stability to withstand the aggressive environment in the blood stream, the formed siRNA nanoparticles were caged with a dithiol containing cross-linker molecules followed by coating them with Poly(Ethylene Glycol) (PEG) polymer. A synthetic analog of Luteinizing Hormone-Releasing Hormone (LHRH) peptide was conjugated to the distal end of PEG polymer to direct the siRNA nanoparticles specifically to the cancer cells. Our results demonstrated that this layer-by-layer modification and targeting approach confers the siRNA nanoparticles stability in plasma and intracellular bioavailability, provides for their specific uptake by tumor cells, accumulation of siRNA in the cytoplasm of cancer cells, and efficient gene silencing. In addition, in vivo body distribution data confirmed high specificity of the proposed targeting delivery approach which created the basis for the prevention of adverse side effects of the treatment on healthy organs. PMID:19567257

Taratula, Oleh; Garbuzenko, Olga B.; Kirkpatrick, Paul; Pandya, Ipsit; Savla, Ronak; Pozharov, Vitaly P.; He, Huixin; Minko, Tamara



LHRH-targeted nanogels as delivery system for cisplatin to ovarian cancer  

PubMed Central

Targeted drug delivery using multifunctional polymeric nanocarriers is a modern approach for cancer therapy. Our purpose was to prepare targeted nanogels for selective delivery of chemotherapeutic agent cisplatin to luteinizing hormone-releasing hormone (LHRH) receptor overexpressing tumor in vivo. Building blocks of such delivery systems consisted of innovative soft block copolymer nanogels with ionic cores serving as a reservoir for cisplatin (loading 35%) and a synthetic analog of LHRH conjugated to the nanogels via poly(ethylene glycol) spacer. Covalent attachment of (D-Lys6)-LHRH to nanogels was shown to be possible without loss in either the ligand binding affinity or the nanogel drug incorporation ability. LHRH-nanogel accumulation was specific to the LHRH-receptor positive A2780 ovarian cancer cells and not towards LHRH-receptor negative SKOV-3 cells. The LHRH-nanogel cisplatin formulation was more effective and less toxic than equimolar doses of free cisplatin or untargeted nanogels in the treatment of receptor-positive ovarian cancer xenografts in mice. Collectively, the study indicates that LHRH mediated nanogel-cisplatin delivery is a promising formulation strategy for therapy of tumors that express the LHRH receptor. PMID:23957812

Nukolova, Natalia V.; Oberoi, Hardeep S.; Zhao, Yi; Chekhonin, Vladimir P.; Kabanov, Alexander V.; Bronich, Tatiana K.



Integrated hollow mesoporous silica nanoparticles for target drug/siRNA co-delivery.  


A hollow mesoporous silica nanoparticle (HMSNP) based drug/siRNA co-delivery system was designed and fabricated, aiming at overcoming multidrug resistance (MDR) in cancer cells for targeted cancer therapy. The as-prepared HMSNPs have perpendicular nanochannels connecting to the internal hollow cores, thereby facilitating drug loading and release. The extra volume of the hollow core enhances the drug loading capacity by two folds as compared with conventional mesoporous silica nanoparticles (MSNPs). Folic acid conjugated polyethyleneimine (PEI-FA) was coated on the HMSNP surfaces under neutral conditions through electrostatic interactions between the partially charged amino groups of PEI-FA and the phosphate groups on the HMSNP surfaces, blocking the mesopores and preventing the loaded drugs from leakage. Folic acid acts as the targeting ligand that enables the co-delivery system to selectively bind with and enter into the target cancer cells. PEI-FA-coated HMSNPs show enhanced siRNA binding capability on account of electrostatic interactions between the amino groups of PEI-FA and siRNA, as compared with that of MSNPs. The electrostatic interactions provide the feasibility of pH-controlled release. In vitro pH-responsive drug/siRNA co-delivery experiments were conducted on HeLa cell lines with high folic acid receptor expression and MCF-7 cell lines with low folic acid receptor expression for comparison, showing effective target delivery to the HeLa cells through folic acid receptor meditated cellular endocytosis. The pH-responsive intracellular drug/siRNA release greatly minimizes the prerelease and possible side effects of the delivery system. By simultaneously delivering both doxorubicin (Dox) and siRNA against the Bcl-2 protein into the HeLa cells, the expression of the anti-apoptotic protein Bcl-2 was successfully suppressed, leading to an enhanced therapeutic efficacy. Thus, the present multifunctional nanoparticles show promising potentials for controlled and targeted drug and gene co-delivery in cancer treatment. PMID:24123533

Ma, Xing; Zhao, Yun; Ng, Kee Woei; Zhao, Yanli



Enhanced Delivery of Gold Nanoparticles with Therapeutic Potential for Targeting Human Brain Tumors  

NASA Astrophysics Data System (ADS)

The blood brain barrier (BBB) remains a major challenge to the advancement and application of systemic anti-cancer therapeutics into the central nervous system. The structural and physiological delivery constraints of the BBB significantly limit the effectiveness of conventional chemotherapy, thereby making systemic administration a non-viable option for the vast majority of chemotherapy agents. Furthermore, the lack of specificity of conventional systemic chemotherapy when applied towards malignant brain tumors remains a major shortcoming. Hence novel therapeutic strategies that focus both on targeted and enhanced delivery across the BBB are warranted. In recent years nanoparticles (NPs) have emerged as attractive vehicles for efficient delivery of targeted anti-cancer therapeutics. In particular, gold nanoparticles (AuNPs) have gained prominence in several targeting applications involving systemic cancers. Their enhanced permeation and retention within permissive tumor microvasculature provide a selective advantage for targeting. Malignant brain tumors also exhibit transport-permissive microvasculature secondary to blood brain barrier disruption. Hence AuNPs may have potential relevance for brain tumor targeting. However, the permeation of AuNPs across the BBB has not been well characterized, and hence is a potential limitation for successful application of AuNP-based therapeutics within the central nervous system (CNS). In this dissertation, we designed and characterized AuNPs and assessed the role of polyethylene glycol (PEG) on the physical and biological properties of AuNPs. We established a size-dependent permeation profile with respect to core size as well as PEG length when AuNPs were assessed through a transport-permissive in-vitro BBB. This study was the first of its kind to systematically examine the influence of design on permeation of AuNPs through transport-permissive BBB. Given the significant delivery limitations through the non-transport permissive and intact BBB, we also assessed the role of magnetic resonance imaging (MRI) guided focused ultrasound (MRgFUS) disruption of the BBB in enhancing permeation of AuNPs across the intact BBB and tumor BBB in vivo. MRgFUS is a novel technique that can transiently increase BBB permeability thereby allowing delivery of therapeutics into the CNS. We demonstrated enhanced delivery of AuNPs with therapeutic potential into the CNS via MRgFUS. Our study was the first to establish a definitive role for MRgFUS in delivering AuNPs into the CNS. In summary, this thesis describes results from a series of research projects that have contributed to our understanding of the influence of design features on AuNP permeation through the BBB and also the potential role of MRgFUS in AuNP permeation across the BBB.

Etame, Arnold B.


Near-Infrared Light-Responsive Core-Shell Nanogels for Targeted Drug Delivery  

PubMed Central

A near-infrared light-responsive drug delivery platform based on Au-Ag-nanorods (Au-Ag NRs) coated with DNA-crosslinked polymeric shells was constructed. DNA complementarity has been applied to develop a polyacrylamide-based sol-gel transition system to encapsulate anticancer drugs into the gel scaffold. The Au-Ag NR based nanogels can also be readily functionalized with targeting moieties, such as aptamers, for specific recognition of tumor cells. When exposed to NIR irradiation, the photothermal effect of the Au-Ag NRs leads to a rapid rise in the temperature of the surrounding gel, resulting in the fast release of the encapsulated payload with high controllability. In vitro study confirmed that aptamer functionalized nanogels can be used as drug carriers feasible for targeted drug delivery with remote control capability by NIR light with high spatial/temporal resolution. PMID:21542633

Kang, Huaizhi; Trondoli, Anna Carolina; Zhu, Guizhi; Chen, Yan; Chang, Ya-Jen; Liu, Haipeng; Huang, Yu-Fen; Zhang, Xiaoling; Tan, Weihong



Development of multiple-layer polymeric particles for targeted and controlled drug delivery  

PubMed Central

The purpose of this work was to develop multilayered particles consisting of a magnetic core and two encompassing shells made up of poly (N-isopropylacrylamide) (PNIPAAm) and poly(d,l-lactide-co-glycolide) (PLGA) for targeted and controlled drug delivery. Transmission electron microscopy confirmed that multilayered particles were obtained with PNIPAAm magnetic nanoparticles embedded within the PLGA shell. Factorial analysis studies also showed that the particle size was inversely proportional to the surfactant concentration and sonication power and directly proportional to the PLGA concentration. Drug-release results demonstrated that these multilayer particles produced an initial burst release and a subsequent sustained release of both bovine serum albumin (BSA) and curcumin loaded into the core and shell of the particle, respectively. BSA release was also affected by changes in temperature. In conclusion, our results indicate that the multilayered magnetic particles could be synthesized and used for targeted and controlled delivery of multiple drugs with different release mechanisms. PMID:19699325

Koppolu, Bhanuprasanth; Rahimi, Maham; Nattama, Sivaniarvindpriya; Wadajkar, Aniket; Nguyen, Kytai Truong



Transferrin receptors and the targeted delivery of therapeutic agents against cancer  

PubMed Central

Background Traditional cancer therapy can be successful in destroying tumors, but can also cause dangerous side effects. Therefore, many targeted therapies are in development. The transferrin receptor (TfR) functions in cellular iron uptake through its interaction with transferrin. This receptor is an attractive molecule for the targeted therapy of cancer since it is upregulated on the surface of many cancer types and is efficiently internalized. This receptor can be targeted in two ways: 1) for the delivery of therapeutic molecules into malignant cells or 2) to block the natural function of the receptor leading directly to cancer cell death. Scope of review In the present article we discuss the strategies used to target the TfR for the delivery of therapeutic agents into cancer cells. We provide a summary of the vast types of anti-cancer drugs that have been delivered into cancer cells employing a variety of receptor binding molecules including Tf, anti-TfR antibodies, or TfR-binding peptides alone or in combination with carrier molecules including nanoparticles and viruses. Major conclusions Targeting the TfR has been shown to be effective in delivering many different therapeutic agents and causing cytotoxic effects in cancer cells in vitro and in vivo. General significance The extensive use of TfR for targeted therapy attests to the versatility of targeting this receptor for therapeutic purposes against malignant cells. More advances in this area are expected to further improve the therapeutic potential of targeting the TfR for cancer therapy leading to an increase in the number of clinical trials of molecules targeting this receptor. PMID:21851850

Daniels, Tracy R.; Bernabeu, Ezequiel; Rodríguez, José A.; Patel, Shabnum; Kozman, Maggie; Chiappetta, Diego A.; Holler, Eggehard; Ljubimova, Julia Y.; Helguera, Gustavo; Penichet, Manuel L.



Targeted Delivery of siRNA to Macrophages for Anti-inflammatory Treatment  

Microsoft Academic Search

Inflammation mediated by tumor necrosis factor-? (TNF-?) and the associated neuronal apoptosis characterizes a number of neurologic disorders. Macrophages and microglial cells are believed to be the major source of TNF-? in the central nervous system (CNS). Here, we show that suppression of TNF-? by targeted delivery of small interfering RNA (siRNA) to macrophage\\/microglial cells dramatically reduces lipopolysaccharide (LPS)-induced neuroinflammation

Sang-Soo Kim; Chunting Ye; Priti Kumar; Isaac Chiu; Sandesh Subramanya; Haoquan Wu; Premlata Shankar; N Manjunath



Self-assembling chitosan\\/poly-?-glutamic acid nanoparticles for targeted drug delivery  

Microsoft Academic Search

For the purpose of targeted drug delivery, composite biodegradable nanoparticles were prepared from chitosan and the poly-?-glutamic\\u000a acid via an ionotropic gelation process. These stable self-assembled nanoparticles were characterized by dynamic light scattering,\\u000a transmission electron microscopy, and atomic force microscopy, which demonstrated that the nanosystem consists of spherical\\u000a particles with a smooth surface both in aqueous environment and in dried

Zsolt Keresztessy; Magdolna Bodnár; Elizabeth Ber; István Hajdu; Min Zhang; John F. Hartmann; Tamara Minko; János Borbély



Nucleolin targeting AS1411 modified protein nanoparticle for antitumor drugs delivery.  


Over recent years, cell surface nucleolin as an anticancer target has attracted many researchers' attentions. To improve the antitumor efficacy, we developed a nucleolin targeted protein nanoparticle (NTPN) delivery system in which human serum albumin (HSA) was used as drug carrier and a DNA aptamer named AS1411, which had high affinity to nucleolin, was used as a bullet. The HSA nanoparticles (NPs-PTX) were fabricated by a novel self-assembly method and then modified with AS1411 (Apt-NPs-PTX). The resulted Apt-NPs-PTX were spherical. Compared with NPs-PTX, the uptake of Apt-NPs-PTX displayed a significant increase in MCF-7 cells while there was a decrease in nontumor cell lines such as MCF-10A and 3T3 cells. In a cytotoxic study, Apt-NPs-PTX displayed an enhanced cytotoxicity in MCF-7 tumor cells while there was almost no cytotoxicity in MCF-10A cells. Endostatin, a nucleolin inhibitor, could significantly decrease the internalization of Apt-NPs-PTX, suggesting nucleolin mediates the transmembrane process of Apt-NPs-PTX. Therefore, the AS1411 modified NTPN delivery system might be a promising targeted drug delivery system. PMID:23679916

Wu, Jinhui; Song, Chenchen; Jiang, Chenxiao; Shen, Xin; Qiao, Qian; Hu, Yiqiao



Formulation design for target delivery of iron nanoparticles to TCE zones  

NASA Astrophysics Data System (ADS)

Nanoparticles of zero-valent iron (NZVI) are effective reducing agents for some dense non-aqueous phase liquid (DNAPL) contaminants such as trichloroethylene (TCE). However, target delivery of iron nanoparticles to DNAPL zones in the aquifer remains an elusive feature for NZVI technologies. This work discusses three strategies to deliver iron nanoparticles to DNAPL zones. To this end, iron oxide nanoparticles coated with oleate (OL) ions were used as stable analogs for NZVI. The OL-coated iron oxide nanoparticles are rendered lipophilic via (a) the addition of CaCl2, (b) acidification, or (c) the addition of a cationic surfactant, benzethonium chloride (BC). Mixtures of OL and BC show promise as a target delivery strategy due to the high stability of the nanoparticles in water, and their preferential partition into TCE in batch experiments. Column tests show that while the OL-BC coated iron oxide nanoparticles remain largely mobile in TCE-free columns, a large fraction of these particles are retained in TCE-contaminated columns, confirming the effectiveness of this target delivery strategy.

Wang, Ziheng; Acosta, Edgar



Targeted Polymeric Micelle System for Delivery of Combretastatin A4 to Tumor Vasculature In Vitro  

Microsoft Academic Search

Purpose  To develop an efficient tumor vasculature-targeted polymeric micelle delivery system for combretastatin A4 (CA4), a novel\\u000a antivascular agent.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  CA4-loaded micelles were prepared from poly (ethylene glycol)-b-poly (d, l-lactide) copolymers. RGD peptides that target integrins ?v?3 and ?v?5, markers of angiogenic endothelial cells,\\u000a were coupled to the surface of micelles. The micelles were characterized in terms of particle size, morphology, drug

Yiguang Wang; Tingyuan Yang; Xun Wang; Jiancheng Wang; Xuan Zhang; Qiang Zhang



Self-assembled nanoplatform for targeted delivery of chemotherapy agents via affinity-regulated molecular interactions  

PubMed Central

Site-specific delivery of drugs while minimizing unwanted distribution has been one of the pursued goals in cancer therapy. In this endeavor, we have developed targeted polymeric nanoparticles called amphiphilic urethane acrylate nonionomer (UAN) for encapsulation of diverse water-insoluble drugs and diagnostic agents, as well as for simple and reproducible surface conjugation of targeting ligands. Using monoclonal antibodies or lymphocyte function-associated antigen-1 (LFA-1) I domain engineered for varying affinities to intercellular adhesion molecule (ICAM)-1, we were able to deliver UAN nanoparticles to human cancer cells with the efficiency dependent on the strength of the molecular interactions and the degree of ICAM-1 expression on cell surface. Compared to non-specific uptake of free drugs, targeted delivery of UAN nanoparticles carrying equal amount of drugs produced more potent cytotoxicity. Notably, without the targeting ligands attached, UAN nanoparticles were largely precluded from non-specific uptake by the cells, resulting in much lower toxicity. The versatility of our UAN nanoparticles in both payload encapsulation and presentation of targeting ligands may facilitate developing a robust platform for evaluating various combinations of cancer drugs and molecular interactions toward developing effective cancer therapy formulations. PMID:20667589

Park, Spencer; Kang, Sungkwon; Veach, Alexander J.; Vedvyas, Yogindra; Zarnegar, Rasa; Kim, Ju-Young; Jin, Moonsoo M.



Magnetic chitosan nanoparticles as a drug delivery system for targeting photodynamic therapy  

NASA Astrophysics Data System (ADS)

Photodynamic therapy (PDT) has become an increasingly recognized alternative to cancer treatment in clinic. However, PDT therapy agents, namely photosensitizer (PS), are limited in application as a result of prolonged cutaneous photosensitivity, poor water solubility and inadequate selectivity, which are encountered by numerous chemical therapies. Magnetic chitosan nanoparticles provide excellent biocompatibility, biodegradability, non-toxicity and water solubility without compromising their magnetic targeting. Nevertheless, no previous attempt has been reported to develop an in vivo magnetic drug delivery system with chitosan nanoparticles for magnetic resonance imaging (MRI) monitored targeting photodynamic therapy. In this study, magnetic targeting chitosan nanoparticles (MTCNPs) were prepared and tailored as a drug delivery system and imaging agents for PS, designated as PHPP. Results showed that PHPP-MTCNPs could be used in MRI monitored targeting PDT with excellent targeting and imaging ability. Non-toxicity and high photodynamic efficacy on SW480 carcinoma cells both in vitro and in vivo were achieved with this method at the level of 0-100 µM. Notably, localization of nanoparticles in skin and hepatic tissue was significantly less than in tumor tissue, therefore photosensitivity and hepatotoxicity can be attenuated.

Sun, Yun; Chen, Zhi-long; Yang, Xiao-xia; Huang, Peng; Zhou, Xin-ping; Du, Xiao-xia



Bifunctional Coupling Agents for Radiolabeling of Biomolecules and Target-Specific Delivery of Metallic Radionuclides  

PubMed Central

Receptor-based radiopharmaceuticals are of great current interest in early molecular imaging and radiotherapy of cancers, and provide a unique tool for target-specific delivery of radionuclides to the diseased tissues. In general, a target-specific radiopharmaceutical can be divided into four parts: targeting biomolecule (BM), pharmacokinetic modifying (PKM) linker, bifunctional coupling or chelating agent (BFC), and radionuclide. The targeting biomolecule serves as a “carrier” for specific delivery of the radionuclide. PKM linkers are used to modify radiotracer excretion kinetics. BFC is needed for radiolabeling of biomolecules with a metallic radionuclide. Different radiometals have significant difference in their coordination chemistry, and require BFCs with different donor atoms and chelator frameworks. Since the radiometal chelate can have a significant impact on physical and biological properties of the target-specific radiopharmaceutical, its excretion kinetics can be altered by modifying the coordination environment with various chelators or coligand, if needed. This review will focus on the design of BFCs and their coordination chemistry with technetium, copper, gallium, indium, yttrium and lanthanide radiometals. PMID:18538888

Liu, Shuang



Nucleic Acid aptamer-mediated drug delivery for targeted cancer therapy.  


Aptamers are emerging as promising therapeutic agents and recognition elements. In particular, cell-SELEX (systematic evolution of ligands by exponential enrichment) allows in vitro selection of aptamers selective to whole cells without prior knowledge of the molecular signatures on the cell surface. The advantage of aptamers is their high affinitiy and binding specificity towards the target. This Minireview focuses on single-stranded (ss) oligonucleotide (DNA or RNA)-based aptamers as cancer therapeutics/theranostics. Specifically, aptamer-nanomaterial conjugates, aptamer-drug conjugates, targeted phototherapy and targeted biotherapy are covered in detail. In reviewing the literature, the potential of aptamers as delivery systems for therapeutic and imaging applications in cancer is clear, however, major challenges remain to be resolved, such as the poorly understood pharmacokinetics, toxicity and off-target effects, before they can be fully exploited in a clinical setting. PMID:25277749

Zhu, Huijie; Li, Jin; Zhang, Xiao-Bing; Ye, Mao; Tan, Weihong



Evaluation of biosafety and intracellular uptake of Cremophor EL free paclitaxel elastic liposomal formulation.  


The present study examines the acute, sub-acute toxicity, and cytotoxicity of paclitaxel elastic liposomal formulation in comparison to a marketed Cremophor EL (polyoxyethylated castor oil):ethanol (1:1, v/v) based formulation. In the previous study, Cremophor EL free paclitaxel elastic liposomal formulation was developed and characterized. Cytotoxicity of formulation was evaluated by MTT assay using A549 cell lines. Percentage intracellular uptake of paclitaxel elastic liposomal and marketed formulation was determined using a fluorescence activating cell sorting assay (FACS) and fluorescence microscopy techniques. Single and repeated dose toxicity measurement showed no mortality, hematological, biochemical, or histopathological changes up to a dose of 120?mg/kg for paclitaxel elastic liposomal formulation, in comparison the marketed formulation showed toxicity at a dose of 40?mg/kg. Maximum tolerated dose (MTD) for paclitaxel elastic liposomal and marketed formulation was found to be 160?mg/kg and 40?mg/kg, respectively. Results of FACS analysis showed a 94.6?±?2.5% intracellular uptake of fluorescence marker acridine orange (AO) loaded in elastic liposomes; in comparison the AO solution showed only a 19.8?±?1.1% uptake. Paclitaxel elastic liposomal formulation seems to be a better alternative for safe and effective delivery of paclitaxel. This study proves the safety and higher intracellular uptake of paclitaxel elastic liposomal formulation. PMID:22074176

Utreja, Puneet; Jain, Subheet; Tiwary, A K



Enhanced Affinity Bifunctional Bisphosphonates for Targeted Delivery of Therapeutic Agents to Bone  

PubMed Central

Skeletal diseases have a major impact on the worldwide population and economy. Although several therapeutic agents and treatments are available for addressing bone diseases, they are not being fully utilized because of their uptake in non-targeted sites and related side effects. Active targeting with controlled delivery is an ideal approach for treatment of such diseases. Because bisphosphonates are known to have high affinity to bone and are being widely used in treatment of osteoporosis, they are well-suited for drug targeting to bone. In this study, a targeted delivery of therapeutic agent to resorption sites and wound healing sites of bone was explored. Towards this goal, bifunctional hydrazine-bisphosphonates (HBPs), with spacers of various lengths, were synthesized and studied for their enhanced affinity to bone. Crystal growth inhibition studies showed that these HBPs have high affinity to hydroxyapatite, and HBPs with shorter spacers bind stronger than alendronate to hydroxyapatite. The HBPs did not affect proliferation of MC3T3-E1 pre-osteoblasts, did not induce apoptosis, and were not cytotoxic at the concentration range tested (10?6 - 10?4 M). Furthermore, drugs can be linked to the HBPs through a hydrazone linkage that is cleavable at the low pH of bone resorption and wound healing sites, leading to release of the drug. This was demonstrated using hydroxyapatite as a model material of bone and 4-nitrobenzaldehyde as a model drug. This study suggests that these HBPs could be used for targeted delivery of therapeutic agents to bone. PMID:22073906

Yewle, Jivan N.; Puleo, David A.; Bachas, Leonidas G.



Gene delivery with active targeting to ovarian cancer cells mediated by folate receptor alpha.  


Folate receptor alpha (FRalpha) is overexpressed on ovarian cancer cells and is a promising molecular target for ovarian cancer gene therapy, but there was still no related report. In this study, folate modified cationic liposomes (F-PEG-CLPs) for ovarian cancer gene delivery were developed for the first time. Folate-poly(ethylene glycol)-succinate-cholesterol (F-PEG-suc-Chol) was firstly synthesized and then used to prepare folate-targeted cationic liposomes/plasmid DNA complexes (F-targeted lipoplexes). F-targeted lipoplexes were prepared by post-insertion method, and displayed membrane structure by transmission electron microscopy observation with the diameter of 193 nm-200 nm and the zeta potential of 35 mV-38 mV. DNase degradation experiments showed that plasmid DNA could be effectively shielded by F-targeted lipoplexes in vitro. F-targeted lipoplexes could transfer gene into human ovarian carcinoma cell line SKOV-3, and 0.1% F-PEG-CLPs composed by DOTAP/Chol/mPEG-Chol/F-PEG-suc-Chol (50:45:5:0.1, molar ratio) had the highest transfection efficiency. The transfection activity of F-targeted lipoplexes could be competitively inhibited by free folic acid, demonstrating that folate-FRalpha interaction caused high transfection efficiency of F-targeted lipoplexes. The uptake mechanism of F-targeted lipoplexes was further validated on human oral carcinoma cell line KB and human liver carcinoma cell line HepG2. The concentration-dependent and time-dependent cytotoxicity of targeted material F-PEG-suc-Chol was observed by MTT assay on SKOV-3 cell and its application would not increase the cytotoxicity of F-targeted lipoplexes in SKOV-3 cells. All the data indicated that F-PEG-CLPs would be a promising gene vector targeting for ovarian cancer therapy. PMID:23802413

He, Zhiyao; Yu, Yiyi; Zhang, Ying; Yan, Yongdong; Zheng, Yu; He, Jun; Xie, Yongmei; He, Gu; Wei, Yuquan; Song, Xiangrong



Nanoparticle-mediated delivery of siRNA targeting Parp1 extends survival of mice bearing tumors  

E-print Network

Nanoparticle-mediated delivery of siRNA targeting Parp1 extends survival of mice bearing tumors the survival of mice bearing tumors derived from Brca1-deficient ovarian cancer cells but not from Brca1 wild

Bhatia, Sangeeta


Cancer Nanotheranostics: Improving Imaging and Therapy by Targeted Delivery across Biological Barriers  

PubMed Central

Cancer nanotheranostics aims to combine imaging and therapy of cancer through use of nanotechnology. The ability to engineer nanomaterials to interact with cancer cells at the molecular level can significantly improve the effectiveness and specificity of therapy to cancers that are currently difficult to treat. In particular, metastatic cancers, drug-resistant cancers, and cancer stem cells impose the greatest therapeutic challenge that requires targeted therapy to treat effectively. Targeted therapy can be achieved with appropriate designed drug delivery vehicles such as nanoparticles, adult stem cells, or T cells in immunotherapy. In this article, we first review the different types of materials commonly used to synthesize nanotheranostic particles and their use in imaging. We then discuss biological barriers that these nanoparticles encounter and must bypass to reach the target cancer cells, including the blood, liver, kidneys, spleen, and particularly the blood-brain barrier. We then review how nanotheranostics can be used to improve targeted delivery and treatment of cancer cells using nanoparticles, adult stem cells, and T cells in immunotherapy. Finally, we discuss development of nanoparticles to overcome current limitations in cancer therapy. PMID:21842473

Kievit, Forrest M.; Zhang, Miqin



Carrier-free, functionalized pure drug nanorods as a novel cancer-targeted drug delivery platform  

NASA Astrophysics Data System (ADS)

A one-dimensional drug delivery system (1D DDS) is highly attractive since it has distinct advantages such as enhanced drug efficiency and better pharmacokinetics. However, drugs in 1D DDSs are all encapsulated in inert carriers, and problems such as low drug loading content and possible undesirable side effects caused by the carriers remain a serious challenge. In this paper, a novel, carrier-free, pure drug nanorod-based, tumor-targeted 1D DDS has been developed. Drugs are first prepared as nanorods and then surface functionalized to achieve excellent water dispersity and stability. The resulting drug nanorods show enhanced internalization rates mainly through energy-dependent endocytosis, with the shape-mediated nanorod (NR) diffusion process as a secondary pathway. The multiple endocytotic mechanisms lead to significantly improved drug efficiency of functionalized NRs with nearly ten times higher cytotoxicity than those of free molecules and unfunctionalized NRs. A targeted drug delivery system can be readily achieved through surface functionalization with targeting group linked amphipathic surfactant, which exhibits significantly enhanced drug efficacy and discriminates between cell lines with high selectivity. These results clearly show that this tumor-targeting DDS demonstrates high potential toward specific cancer cell lines.

Li, Yanan; Yang, Yinlong; An, Feifei; Liu, Zhuang; Zhang, Xiujuan; Zhang, Xiaohong



Molecularly self-assembled nucleic acid nanoparticles for targeted in vivo siRNA delivery  

NASA Astrophysics Data System (ADS)

Nanoparticles are used for delivering therapeutics into cells. However, size, shape, surface chemistry and the presentation of targeting ligands on the surface of nanoparticles can affect circulation half-life and biodistribution, cell-specific internalization, excretion, toxicity and efficacy. A variety of materials have been explored for delivering small interfering RNAs (siRNAs)--a therapeutic agent that suppresses the expression of targeted genes. However, conventional delivery nanoparticles such as liposomes and polymeric systems are heterogeneous in size, composition and surface chemistry, and this can lead to suboptimal performance, a lack of tissue specificity and potential toxicity. Here, we show that self-assembled DNA tetrahedral nanoparticles with a well-defined size can deliver siRNAs into cells and silence target genes in tumours. Monodisperse nanoparticles are prepared through the self-assembly of complementary DNA strands. Because the DNA strands are easily programmable, the size of the nanoparticles and the spatial orientation and density of cancer-targeting ligands (such as peptides and folate) on the nanoparticle surface can be controlled precisely. We show that at least three folate molecules per nanoparticle are required for optimal delivery of the siRNAs into cells and, gene silencing occurs only when the ligands are in the appropriate spatial orientation. In vivo, these nanoparticles showed a longer blood circulation time (t1/2 ~ 24.2 min) than the parent siRNA (t1/2 ~ 6 min).

Lee, Hyukjin; Lytton-Jean, Abigail K. R.; Chen, Yi; Love, Kevin T.; Park, Angela I.; Karagiannis, Emmanouil D.; Sehgal, Alfica; Querbes, William; Zurenko, Christopher S.; Jayaraman, Muthusamy; Peng, Chang G.; Charisse, Klaus; Borodovsky, Anna; Manoharan, Muthiah; Donahoe, Jessica S.; Truelove, Jessica; Nahrendorf, Matthias; Langer, Robert; Anderson, Daniel G.



Formulation of Functionalized PLGA-PEG Nanoparticles for In Vivo Targeted Drug Delivery  

PubMed Central

Nanoparticle (NP) size has been shown to significantly effect the biodistribution of targeted and non-targeted NPs in an organ specific manner. Herein we have developed NPs from carboxy-terminated poly (d,l-lactide-co-glycolide)-block-poly(ethylene glycol) (PLGA-b-PEG-COOH) polymer and studied the effects of altering the following formulation parameters on the size of NPs, including: 1) polymer concentration, 2) drug loading, 3) water miscibility of solvent, and 4) the ratio of water to solvent. We found that NP mean volumetric size correlates linearly with polymer concentration for NPs between 70 and 250 nm in diameter (linear coefficient = 0.99 for NPs formulated with solvents studied). NPs with desirable size, drug loading, and polydispersity were conjugated to the A10 RNA aptamer (Apt) that binds to the Prostate Specific Membrane Antigen (PSMA), and NP and NP-Apt biodistribution was evaluated in a LNCaP (PSMA+) xenograft mouse model of PCa. The surface functionalization of NPs with the A10 PSMA aptamer significantly enhanced delivery of NPs to tumors vs. equivalent NPs lacking the A10 PSMA aptamer (a 3.77-fold increase at 24 hrs; NP-Apt 0.83% ± 0.21% vs. NP 0.22% ± 0.07% of injected dose per gram of tissue; mean ± s.d., n = 4, p = 0.002). The ability to control NP size together with targeted delivery may result in favorable biodistribution and development of clinically relevant targeted therapies. PMID:17055572

Cheng, Jianjun; Teply, Benjamin A.; Sherifi, Ines; Sung, Josephine; Luther, Gaurav; Gu, Frank X.; Levy-Nissenbaum, Etgar; Radovic-Moreno, Aleksandar F.; Langer, Robert; Farokhzad, Omid C.



Cardiological Biopharmaceuticals in the Conception of Drug Targeting Delivery: Practical Results and Research Perspectives  

PubMed Central

The results of the clinical use of thrombolytic and antithrombotic preparations developed on the basis of protein conjugates obtained within the framework of the conception of drug targeting delivery in the organism are considered. A decrease has been noted in the number of biomedical projects focused on these derivatives as a result of various factors: the significant depletion of financial and organizational funds, the saturation of the pharmaceutical market with preparations of this kind, and the appearance of original means for interventional procedures. Factors that actively facilitate the conspicuous potentiation of the efficacy of bioconjugates were revealed: the biomedical testing of protein domains and their selected combinations, the optimization of molecular sizes for the bioconjugates obtained, the density of target localization, the application of cell adhesion molecules as targets, and the application of connected enzyme activities. Enzyme antioxidants and the opportunity for further elaboration of the drug delivery conception via the elucidation and formation of therapeutic targets for effective drug reactions by means of pharmacological pre- and postconditioning of myocardium arouse significant interest. PMID:23150805

Maksimenko, A.V.



Targeted Delivery of Antibiotics to Intracellular Chlamydial Infections using PLGA Nanoparticles  

PubMed Central

Chlamydia trachomatis and C pneumoniae are intracellular bacterial pathogens that have been shown to cause, or are strongly associated with, diverse chronic diseases. Persistent infections by both organisms are refractory to antibiotic therapy. The lack of therapeutic efficacy results from the attenuated metabolic rate of persistently infecting chlamydiae in combination with the modest intracellular drug concentrations achievable by normal delivery of antibiotics to the inclusions within which chlamydiae reside in the host cell cytoplasm. In this research, we evaluated whether nanoparticles formulated using the biodegradable poly(d-L-lactide-co-glycolide) (PLGA) polymer can enhance the delivery of antibiotics to the chlamydial inclusion complexes. We initially studied the trafficking of PLGA nanoparticles in Chlamydia-infected cells. We then evaluated nanoparticles for the delivery of antibiotics to the inclusions. Intracellular trafficking studies show that PLGA nanoparticles efficiently concentrate in inclusions in both acutely and persistently infected cells. Further, encapsulation of rifampin and azithromycin antibiotics in PLGA nanoparticles enhanced the effectiveness of the antibiotics in reducing microbial burden. Combination of rifampin and azithromycin was more effective than the individual drugs. Overall, our studies show that PLGA nanoparticles can be effective carriers for targeted delivery of antibiotics to intracellular chlamydial infections. PMID:21652065

Toti, Udaya S.; Guru, Bharath R.; Hali, Mirabela; McPharlin, Christopher; Wykes, Susan M.; Panyam, Jayanth; Whittum-Hudson, Judith A.



A comprehensive overview of exosomes as drug delivery vehicles - endogenous nanocarriers for targeted cancer therapy.  


Exosomes denote a class of secreted nanoparticles defined by size, surface protein and lipid composition, and the ability to carry RNA and proteins. They are important mediators of intercellular communication and regulators of the cellular niche, and their altered characteristics in many diseases, such as cancer, suggest them to be important both for diagnostic and therapeutic purposes, prompting the idea of using exosomes as drug delivery vehicles, especially for gene therapy. This review covers the current status of evidence presented in the field of exosome-based drug delivery systems. Components for successful exosome-based drug delivery, such as choice of donor cell, therapeutic cargo, use of targeting peptide, loading method and administration route are highlighted and discussed with a general focus pertaining to the results obtained in models of different cancer types. In addition, completed and on-going clinical trials are described, evaluating exosome-based therapies for the treatment of different cancer types. Due to their endogenous origin, exosome-based drug delivery systems may have advantages in the treatment of cancer, but their design needs further refinement to justify their usage on the clinical scale. PMID:24747178

Johnsen, Kasper Bendix; Gudbergsson, Johann Mar; Skov, Martin Najbjerg; Pilgaard, Linda; Moos, Torben; Duroux, Meg



Non-Condensing Polymeric Nanoparticles for Targeted Gene and siRNA Delivery  

PubMed Central

Gene therapy has shown a tremendous potential to benefit patients in a variety of disease conditions. However, finding a safe and effective systemic delivery system is the major obstacle in this area. Although viral vectors showed promise for high transfection rate, the immunogenicity associated with these systems has hindered further development. As an alternative to viral gene delivery, this review focuses on application of novel safe and effective non-condensing polymeric systems that have shown high transgene expression when administered systemically or by the oral route. Type B gelatin-based engineered nanocarriers were evaluated for passive and active tumor-targeted delivery and transfection using both reporter and therapeutic plasmid DNA. Additionally, we have shown that nanoparticles-in-microsphere oral system (NiMOS) can efficiently deliver reporter and therapeutic gene constructs in the gastrointestinal tract. Additionally, there has been a significant recent interest in the use small interfering RNA (siRNA) as a therapeutic system for gene silencing. Both gelatin nanoparticles and NiMOS have shown activity in systemic and oral delivery of siRNA, respectively. PMID:21621597

Xu, Jing; Ganesh, Shanthi; Amiji, Mansoor



NIR-to-visible upconversion nanoparticles for fluorescent labeling and targeted delivery of siRNA  

NASA Astrophysics Data System (ADS)

Near-infrared (NIR)-to-visible upconversion fluorescent nanoparticles were synthesized and used for imaging and targeted delivery of small interfering RNA (siRNA) to cancer cells. Silica-coated NaYF4 upconversion nanoparticles (UCNs) co-doped with lanthanide ions (Yb/Er) were synthesized. Folic acid and anti-Her2 antibody conjugated UCNs were used to fluorescently label the folate receptors of HT-29 cells and Her2 receptors of SK-BR-3 cells, respectively. The intracellular uptake of the folic acid and antibody conjugated UCNs was visualized using a confocal fluorescence microscope equipped with an NIR laser. siRNA was attached to anti-Her2 antibody conjugated UCNs and the delivery of these nanoparticles to SK-BR-3 cells was studied. Meanwhile, a luciferase assay was established to confirm the gene silencing effect of siRNA. Upconversion nanoparticles can serve as a fluorescent probe and delivery system for simultaneous imaging and delivery of biological molecules.

Jiang, Shan; Zhang, Yong; Lim, Kian Meng; Sim, Eugene K. W.; Ye, Lei



Safety Assessment of Liver-Targeted Hydrodynamic Gene Delivery in Dogs  

PubMed Central

Evidence in support of safety of a gene delivery procedure is essential toward gene therapy. Previous studies using the hydrodynamics-based procedure primarily focus on gene delivery efficiency or gene function analysis in mice. The current study focuses on an assessment of the safety of computer-controlled and liver-targeted hydrodynamic gene delivery in dogs as the first step toward hydrodynamic gene therapy in clinic. We demonstrate that the impacts of the hydrodynamic procedure were limited in the injected region and the influences were transient. Histological examination and the hepatic microcirculation measurement using reflectance spectrophotometry reveal that the liver-specific impact of the procedure involves a transient expansion of the liver sinusoids. No systemic damage or toxicity was observed. Physiological parameters, including electrocardiogram, heart rate, blood pressure, oxygen saturation, and body temperature, remained in normal ranges during and after hydrodynamic injection. Body weight was also examined to assess the long-term effects of the procedure in animals who underwent 3 hydrodynamic injections in 6 weeks with 2-week time interval in between. Serum biochemistry analysis showed a transient increase in liver enzymes and a few cytokines upon injection. These results demonstrate that image-guided, liver-specific hydrodynamic gene delivery is safe. PMID:25251246

Kamimura, Kenya; Kanefuji, Tsutomu; Yokoo, Takeshi; Abe, Hiroyuki; Suda, Takeshi; Kobayashi, Yuji; Zhang, Guisheng; Aoyagi, Yutaka; Liu, Dexi



Cargo-towing fuel-free magnetic nanoswimmers for targeted drug delivery.  


Fuel-free nanomotors are essential for future in-vivo biomedical transport and drug-delivery applications. Herein, the first example of directed delivery of drug-loaded magnetic polymeric particles using magnetically driven flexible nanoswimmers is described. It is demonstrated that flexible magnetic nickel-silver nanoswimmers (5-6 ?m in length and 200 nm in diameter) are able to transport micrometer particles at high speeds of more than 10 ?m s(-1) (more than 0.2 body lengths per revolution in dimensionless speed). The fundamental mechanism of the cargo-towing ability of these magnetic (fuel-free) nanowire motors is modelled, and the hydrodynamic features of these cargo-loaded motors discussed. The effect of the cargo size on swimming performance is evaluated experimentally and compared to a theoretical model, emphasizing the interplay between hydrodynamic drag forces and boundary actuation. The latter leads to an unusual increase of the propulsion speed at an intermediate particle size. Potential applications of these cargo-towing nanoswimmers are demonstrated by using the directed delivery of drug-loaded microparticles to HeLa cancer cells in biological media. Transport of the drug carriers through a microchannel from the pick-up zone to the release microwell is further illustrated. It is expected that magnetically driven nanoswimmers will provide a new approach for the rapid delivery of target-specific drug carriers to predetermined destinations. PMID:22174121

Gao, Wei; Kagan, Daniel; Pak, On Shun; Clawson, Corbin; Campuzano, Susana; Chuluun-Erdene, Erdembileg; Shipton, Erik; Fullerton, Eric E; Zhang, Liangfang; Lauga, Eric; Wang, Joseph



Mathematical Modeling and Optimization of Drug Delivery from Intratumorally Injected Microspheres  

Microsoft Academic Search

Purpose: Paclitaxel is a highly promising phase-sensitive antitumor drug that could conceivably be improved by extended lower dosing as opposed to intermittent higher dosing. Although intratumoral delivery of paclitaxel to the whole tumor at different loads and rates has already been achieved, determining an optimal release mode of paclitaxel for tumor eradication remains difficult. This study set out to rationally

Abraham Rami Tzafriri; Elyakum Itzhak Lerner; Moshe Flashner-Barak; Michael Hinchcliffe; Eli Ratner; Hanna Parnas



Low-density lipoprotein-mimicking nanoparticles for tumor-targeted theranostic applications.  


This study introduces multifunctional lipid nanoparticles (LNPs), mimicking the structure and compositions of low-density lipoproteins, for the tumor-targeted co-delivery of anti-cancer drugs and superparamagnetic nanocrystals. Paclitaxel (4.7 wt%) and iron oxide nanocrystals (6.8 wt%, 11 nm in diameter) are co-encapsulated within folate-functionalized LNPs, which contain a cluster of nanocrystals with an overall diameter of about 170 nm and a zeta potential of about -40 mV. The folate-functionalized LNPs enable the targeted detection of MCF-7, human breast adenocarcinoma expressing folate receptors, in T2 -weighted magnetic resonance images as well as the efficient intracellular delivery of paclitaxel. Paclitaxel-free LNPs show no significant cytotoxicity up to 0.2 mg mL(-1) , indicating the excellent biocompatibility of the LNPs for intracellular drug delivery applications. The targeted anti-tumor activities of the LNPs in a mouse tumor model suggest that the low-density lipoprotein-mimetic LNPs can be an effective theranostic platform with excellent biocompatibility for the tumor-targeted co-delivery of various anti-cancer agents. PMID:25137631

Lee, Jeong Yu; Kim, Jin-Ho; Bae, Ki Hyun; Oh, Mi Hwa; Kim, Youngwook; Kim, Jee Seon; Park, Tae Gwan; Park, Keunchil; Lee, Jung Hee; Nam, Yoon Sung



Hyaluronic acid modified mesoporous silica nanoparticles for targeted drug delivery to CD44-overexpressing cancer cells  

NASA Astrophysics Data System (ADS)

In this paper, a targeted drug delivery system has been developed based on hyaluronic acid (HA) modified mesoporous silica nanoparticles (MSNs). HA-MSNs possess a specific affinity to CD44 over-expressed on the surface of a specific cancer cell line, HCT-116 (human colon cancer cells). The cellular uptake performance of fluorescently labelled MSNs with and without HA modification has been evaluated by confocal microscopy and fluorescence-activated cell sorter (FACS) analysis. Compared to bare MSNs, HA-MSNs exhibit a higher cellular uptake via HA receptor mediated endocytosis. An anticancer drug, doxorubicin hydrochloride (Dox), has been loaded into MSNs and HA-MSNs as drug delivery vehicles. Dox loaded HA-MSNs show greater cytotoxicity to HCT-116 cells than free Dox and Dox-MSNs due to the enhanced cell internalization behavior of HA-MSNs. It is expected that HA-MSNs have a great potential in targeted delivery of anticancer drugs to CD44 over-expressing tumors.

Yu, Meihua; Jambhrunkar, Siddharth; Thorn, Peter; Chen, Jiezhong; Gu, Wenyi; Yu, Chengzhong



A novel liposomal formulation of FTY720 (Fingolimod) for promising enhanced targeted delivery  

PubMed Central

We describe here the development and characterization of the physicochemical and pharmacokinetic properties of a novel liposomal formulation for FTY720 delivery, LP-FTY720. The mean diameter of LP-FTY720 was ~157 nm, and the FTY720 entrapment efficiency was ~85%. The liposomal formulation protected FTY720 from degradation in aqueous buffer and showed toxicity in CLL patient B cells comparable to that of free FTY720. Following intravenous injection in ICR mice, LP-FTY720 had an increased elimination phase half-life (~28 vs. ~19 hr) and decreased clearance (235 vs. 778 mL/h/kg) compared to the free drug. Antibodies against CD19, CD20 and CD37 were incorporated into LP-FTY720, which provided targeted delivery to CLL patient B cells and thus achieved higher killing efficacy. The novel liposomal carrier of FTY720 demonstrated improved pharmacokinetic properties, comparable activity, and a potential platform for targeted delivery to CLL by overcoming the limited application of free FTY720 to B malignancy treatment. PMID:23969101

Mao, Yicheng; Wang, Jiang; Zhao, Yuan; Wu, Yun; Kwak, Kwang Joo; Chen, Ching-Shih; Byrd, John C.; Lee, Robert J.; Phelps, Mitch A.; Lee, L. James; Muthusamy, Natarajan



Synthesis and Characterization of Polymer Nanocarriers for the Targeted Delivery of Therapeutic Enzymes  

PubMed Central

Protein drugs, such as recombinant enzymes useful for detoxification and replacement therapies, have extraordinary specificity and potency. However, inherently inadequate delivery to target sites and rapid inactivation limit their medical utility. Using chaperone polymeric particles designed within an injectible size range (sub-micron) may help solve these shortcomings. Such nanocarriers would (i) prevent premature inactivation of encapsulated therapeutic protein cargoes, (ii) provide a carrier that can be surface decorated by targeting ligands, and (iii) optimize sub-cellular localization of the drug. This chapter describes the techniques successfully employed for the preparation of polymer nanocarriers (PNC) loaded with the antioxidant enzyme, catalase, and targeted to endothelial cells. Methods of PNC synthesis, loading with catalase, characterization, coupling of a targeting moiety, and in vitro testing of the enzymatic and targeting activities are provided here. Advantages and disadvantages of specific designs are discussed. Due to the modular nature of the targeting methodology employed, it is believed that these protocols will provide a solid foundation for the formulation of a wide variety of enzymatic drug targeting strategies. PMID:20013177

Simone, Eric; Dziubla, Thomas; Shuvaev, Vladimir; Muzykantov, Vladimir R.



Design and fabrication of magnetic nanoparticles for targeted drug delivery and imaging  

PubMed Central

Magnetic nanoparticles (MNPs) represent a class of non-invasive imaging agents that have been developed for magnetic resonance (MR) imaging. These MNPs have traditionally been used for disease imaging via passive targeting, but recent advances have opened the door to cellular-specific targeting, drug delivery, and multi-modal imaging by these nanoparticles. As more elaborate MNPs are envisioned, adherence to proper design criteria (e.g. size, coating, molecular functionalization) becomes even more essential. This review summarizes the design parameters that affect MNP performance in vivo, including the physicochemical properties and nanoparticle surface modifications, such as MNP coating and targeting ligand functionalizations that can enhance MNP management of biological barriers. A careful review of the chemistries used to modify the surfaces of MNPs is also given, with attention paid to optimizing the activity of bound ligands while maintaining favorable physicochemical properties. PMID:19909778

Veiseh, Omid; Gunn, Jonathan; Zhang, Miqin



Investigation of strategies for drug delivery by combination targeting of nanocarriers to multiple epitopes or receptors  

NASA Astrophysics Data System (ADS)

Development of drug delivery systems (ie. nanocarriers) with controllable composition, architecture, and functionalities is heavily investigated in the field of drug delivery in order to improve clinical interventions. Designing drug nanocarriers which possess targeting properties is critical to enable them to reach the intended site of intervention in the body. To achieve this goal, the surface of drug nanocarriers can be modified with targeting moieties (antibodies, peptides, etc.) addressed to cell surface molecules expressed on the diseased tissues and cells. If these molecules are receptors capable of internalizing bound ligands via endocytosis, targeting can then enable drug transport into cells or across cellular barriers in the body. Yet, addressing nanocarriers to single targets presents limited control over cellular interactions and biodistribution. Since most cell-surface markers are not exclusively expressed in a precise site in vivo, high affinity of targeted nanocarriers may lead to non-desired accumulation in regions of the body associated with low expression. Modification of nanocarriers to achieve combined-targeting (binding to more than one cell-surface receptor) may help modulate binding to cells and also endocytosis, since cell receptors possess distinct functions and features affecting these parameters, such as their expression, location on the plasmalemma, activation in disease, mechanism of endocytosis, etc. Further, targeting nanocarriers to multiple epitopes of the same receptor, a strategy which has never been tested, may also modulate these parameters since they are highly epitope specific. In this dissertation, we investigate the effect of targeting model polymer nanocarriers to: (1) multiple receptors of similar function (intercellular-, platelet-endothelial-, and/or vascular-cell adhesion molecules), (2) multiple receptors of different function (intercellular adhesion molecule 1 and transferrin receptor), or (3) multiple epitopes of the same receptor (transferrin receptor epitopes 8D3 and R17). Binding to cells, endocytosis within cells, and biodistribution in mice were tested. Results indicate that combination targeting enhanced performance of nanocarriers with regard to these three parameters as compared to non-targeted nanocarriers and modulated their outcome relative to single-targeted nanocarriers. This modulation was observed as enhanced, intermediate, or diminished interaction with cells, accumulation in particular organs, and specificity for diseased sites relative to single-targeted nanocarriers. These results were general to strategies 1--3 and were difficult to foresee a priori due to the complex nature of said interactions. Importantly, outcomes depended on the multiplicity (dual- vs. triple-targeting) and/or combination of affinity moieties displayed on the nanocarrier surface, as well as the physiological/pathological state of cells and tissues. Modulation of the delivery of a model therapeutic cargo in mice relative to single-targeted nanocarriers demonstrated the potential of these strategies to control the biodistribution of therapeutic agents. Therefore, these findings illustrate that combination-targeting enables modulation over cellular interactions and biodistribution of nanocarriers, which may aid the development of nanocarriers tailored for particular therapeutic needs.

Papademetriou, Iason Titos


Tumor-targeted liposomal drug delivery mediated by a diseleno bond-stabilized cyclic peptide  

PubMed Central

Peptide ligands have played an important role in tumor-targeted drug delivery as targeting moieties. The in vivo fate of peptide-mediated drug delivery systems and the following antitumor effects may greatly depend on the stability of the peptide ligand. In the current study, a tumor-targeting cyclic peptide screened by phage display, Lyp-1 (a peptide that specifically binds to tumor and endothelial cells of tumor lymphatics in certain tumors), was structurally modified by replacement of the original intramolecular disulfide bond with a diseleno bond. The produced analog Syp-1 (seleno derivative of Lyp-1) maintained specific binding ability to the target protein p32 (Kd = 18.54 nM), which is similar to that of Lyp-1 (Kd = 10.59 nM), indicated by surface plasmon resonance assay. Compared with Lyp-1, Syp-1 showed significantly improved stability against serum. After the peptide attached onto the surface of fluorophore-encapsulating liposomes, the more efficient tumor uptake of liposomal fluorophore mediated by Syp-1 was observed. Furthermore, Syp-1 modified liposomal doxorubicin presented the most potent tumor growth inhibitory ability among all the therapeutic groups, with a low half maximal inhibitory concentration of 588 nM against MDA-MB-435 cells in vitro and a high tumor inhibition rate of 73.5% in vivo. These findings clearly indicated that Syp-1 was a stable and effective tumor targeting ligand and suggest that the sulfur-to-selenium replacement strategy may help stabilize the phage-displayed cyclic peptide containing disulfide-bond under physiological conditions and strongly support the validity of peptide-mediated drug targeting. PMID:23515368

Li, Chong; Wang, Yixin; Zhang, Xiaolin; Deng, Li; Zhang, Yan; Chen, Zhangbao



Molecular evidences for the chemosensitizing efficacy of liposomal curcumin in paclitaxel chemotherapy in mouse models of cervical cancer  

Microsoft Academic Search

The microtubule-targeting antineoplastic agent, paclitaxel, is highly efficacious against a wide spectrum of human cancers. However, dose-limiting toxicity and development of drug resistance limit its clinical application. Development of novel strategies that overcome chemoresistance and sensitize cancer cells to paclitaxel can enhance the therapeutic effect of this drug. We have previously shown that curcumin, a natural polyphenol, enhances paclitaxel-induced cytotoxicity

C N Sreekanth; S V Bava; E Sreekumar; R J Anto



Impact of ?-Targeted Radiation Therapy on Gene Expression in a Pre-Clinical Model for Disseminated Peritoneal Disease when Combined with Paclitaxel  

PubMed Central

To better understand the molecular basis of the enhanced cell killing effected by the combined modality of paclitaxel and 212Pb-trastuzumab (Pac/212Pb-trastuzumab), gene expression in LS-174T i.p. xenografts was investigated 24 h after treatment. Employing a real time quantitative PCR array (qRT-PCR array), 84 DNA damage response genes were quantified. Differentially expressed genes following therapy with Pac/212Pb-trastuzumab included those involved in apoptosis (BRCA1, CIDEA, GADD45?, GADD45?, GML, IP6K3, PCBP4, PPP1R15A, RAD21, and p73), cell cycle (BRCA1, CHK1, CHK2, GADD45?, GML, GTSE1, NBN, PCBP4, PPP1R15A, RAD9A, and SESN1), and damaged DNA repair (ATRX, BTG2, EXO1, FEN1, IGHMBP2, OGG1, MSH2, MUTYH, NBN, PRKDC, RAD21, and p73). This report demonstrates that the increased stressful growth arrest conditions induced by the Pac/212Pb-trastuzumab treatment suppresses cell proliferation through the regulation of genes which are involved in apoptosis and damaged DNA repair including single and double strand DNA breaks. Furthermore, the study demonstrates that 212Pb-trastuzumab potentiation of cell killing efficacy results from the perturbation of genes related to the mitotic spindle checkpoint and BASC (BRCA1-associated genome surveillance complex), suggesting cross-talk between DNA damage repair and the spindle damage response. PMID:25268703

Yong, Kwon Joong; Milenic, Diane E.; Baidoo, Kwamena E.; Brechbiel, Martin W.



Multifunctional disulfide-based cationic dextran conjugates for intravenous gene delivery targeting ovarian cancer cells.  


A folate-decorated, disulfide-based cationic dextran conjugate having dextran as the main chain and disulfide-linked 1,4-bis(3-aminopropyl)piperazine (BAP) residues as the grafts was designed and successfully prepared as a multifunctional gene delivery vector for targeted gene delivery to ovarian cancer SKOV-3 cells in vitro and in vivo. Initially, a new bioreducible cationic polyamide (denoted as pSSBAP) was prepared by polycondensation reaction of bis(p-nitrophenyl)-3,3'-dithiodipropanoate, a disulfide-containing monomer, and BAP. It was found that the pSSBAP was highly efficient for in vitro gene delivery against MCF-7 and SKOV-3 cell lines. Subsequently, two cationic dextran conjugates with different amounts of BAP residues (denoted as Dex-SSBAP6 and Dex-SSBAP30, respectively) were synthesized by coupling BAP to disulfide-linked carboxylated dextran or coupling pSSBAP-oligomer to p-nitrophenyl carbonated dextran. Both two conjugates were able to bind DNA to form nanosized polyplexes with an improved colloidal stability in physiological conditions. The polyplexes, however, were rapidly dissociated to liberate DNA in a reducing environment. In vitro transfection experiments revealed that the polyplexes of Dex-SSBAP30 efficiently transfected SKOV-3 cells, yielding transfection efficiency that is comparable to that of linear polyethylenimine or lipofectamine 2000. AlamarBlue assay showed that the conjugates had low cytotoxicity in vitro at a high concentration of 100 mg/L. Further, Dex-SSBAP30 has primary amine side groups and thus allows for folate (FA) conjugation, yielding FA-coupled Dex-SSBAP30 (Dex-SSBAP30-FA). It was found that Dex-SSBAP30-FA was efficient for targeted gene delivery to SKOV-3 tumor xenografted in a nude mouse model by intravenous injection, inducing a higher level of gene expression in the tumor as compared to Dex-SSBAP30 lacking FA and comparable gene expression to linear polyethylenimine as one of the most efficient polymeric vectors for intravenous gene delivery in vivo. Disulfide-based cationic dextran system thus has a high potential for intravenous gene delivery toward cancer gene therapy. PMID:24892216

Song, Yanyan; Lou, Bo; Zhao, Peng; Lin, Chao



Simultaneous nuclear imaging and intranuclear drug delivery by nuclear-targeted multifunctional upconversion nanoprobes.  


Nuclear-targeted therapy by delivering anticancer drug directly into cancer cell nuclei can elicit synergistic therapeutic effects and kill these cancer cells with much enhanced efficiencies. Besides nuclear targeting, another difficulty in nuclear-targeted therapy is how to achieve real-time monitoring of the therapy process simultaneously. In this article we report on the development of multifunctional upconversion nanoparticles (UCNPs) which were able to target cancer cell nuclei, and thus deliver the anticancer drug directly to the nuclear region and simultaneously image cell nucleus by magnetic resonance (MR)/upconversion fluorescent for real-time guidance of their therapeutic action simultaneously. The Er/Yb-doped NaYF(4) core and NaGdF(4) shell endow the core/shell structured UCNPs with enhanced upconversion fluorescent imaging and more sensitive T(1)-MR imaging performances, and the surface conjugation of TAT peptide served as a key role in the nuclear targeting and nuclear transport process. This multifunctional UCNPs-based nano-theranostic was used to improve the efficacy of DOX in Hela humor tumor models, by direct DOX delivery to the nucleus under the synchronous monitoring of the nano-theranostics. Further development of this technology may provide more exciting opportunities in treating cancer disease by nuclear-targeted therapy. PMID:22796158

Liu, Jia-nan; Bu, Wenbo; Pan, Li-min; Zhang, Shengjian; Chen, Feng; Zhou, Liangping; Zhao, Kuai-le; Peng, Weijun; Shi, Jianlin



Membrane domain formation—a key factor for targeted intracellular drug delivery  

PubMed Central

Protein molecules, toxins and viruses internalize into the cell via receptor-mediated endocytosis (RME) using specific proteins and lipids in the plasma membrane. The plasma membrane is a barrier for many pharmaceutical agents to enter into the cytoplasm of target cells. In the case of cancer cells, tissue-specific biomarkers in the plasma membrane, like cancer-specific growth factor receptors, could be excellent candidates for RME-dependent drug delivery. Recent data suggest that agent binding to these receptors at the cell surface, resulting in membrane domain formation by receptor clustering, can be used for the initiation of RME. As a result, these pharmaceutical agents are internalized into the cells and follow different routes until they reach their final intracellular targets like lysosomes or Golgi. We propose that clustering induced formation of plasma membrane microdomains enriched in receptors, sphingolipids, and inositol lipids, leads to membrane bending which functions as the onset of RME. In this review we will focus on the role of domain formation in RME and discuss potential applications for targeted intracellular drug delivery. PMID:25520666

Popov-?eleketi?, Dušan; van Bergen en Henegouwen, Paul M. P.



Functionalized Single-Walled Carbon Nanotubes as Rationally Designed Vehicles for Tumor-Targeted Drug Delivery  

SciTech Connect

A novel single-walled carbon nanotube (SWNT)-based tumor-targeted drug delivery system (DDS) has been developed, which consists of a functionalized SWNT linked to tumor-targeting modules as well as prodrug modules. There are three key features of this nanoscale DDS: (a) use of functionalized SWNTs as a biocompatible platform for the delivery of therapeutic drugs or diagnostics, (b) conjugation of prodrug modules of an anticancer agent (taxoid with a cleavable linker) that is activated to its cytotoxic form inside the tumor cells upon internalization and in situ drug release, and (c) attachment of tumor-recognition modules (biotin and a spacer) to the nanotube surface. To prove the efficacy of this DDS, three fluorescent and fluorogenic molecular probes were designed, synthesized, characterized, and subjected to the analysis of the receptor-mediated endocytosis and drug release inside the cancer cells (L1210FR leukemia cell line) by means of confocal fluorescence microscopy. The specificity and cytotoxicity of the conjugate have also been assessed and compared with L1210 and human noncancerous cell lines. Then, it has unambiguously been proven that this tumor-targeting DDS works exactly as designed and shows high potency toward specific cancer cell lines, thereby forming a solid foundation for further development.

Chen,J.; Wong,S.; Chen, S.; Zhao, X.; Kuznetsova, L.V.; and Ojima, I.



A dual-functionally modified chitosan derivative for efficient liver-targeted gene delivery.  


Galactosylated chitosan-hydroxypropyltrimethylammonium (gal-HTCC) was synthesized by galactosylating and quaternizing chitosan to endue chitosan with targeting specificity for potential applications as gene vectors. The composition and physicochemical properties of gal-HTCC were characterized by FT-IR, (1) H NMR, elemental analysis, X-ray diffraction, and turbidity measurement. It was found that water-soluble gal-HTCC showed a more amorphous structure than chitosan, and it also had a much better plasmid condensation capability than galactosylated chitosan. Cytotoxicity measurements revealed that gal-HTCC showed significantly lower cytotoxicity in HepG2 and HeLa cell lines compared to branched polyethylenimine (bPEI, 25 kDa) which was used as a positive control. The nanoparticles (NPs) consisted of gal-HTCC and plasmid DNA had desirable particle size (around 250 nm) with a narrow size distribution. Confocal laser scanning microscopy confirmed that NPs could be internalized and transported to the nucleus efficiently within 6 h. In vitro gene transfection results indicated that gal-HTCC had significantly higher transfection efficiency (7- to 32-fold) compared to chitosan and gal-chitosan for targetable delivery of pGL3 luciferase plasmid to HepG2, and its transfection efficiency was highly inhibited in the presence of galactose (20 mM). All these results suggest that gal-HTCC can function as a promising nonviral gene vector for efficient liver-targeted gene delivery. PMID:23203540

Xiao, Bo; Wang, Xiaoyu; Qiu, Zhiye; Ma, Jun; Zhou, Lei; Wan, Ying; Zhang, Shengmin



Hyaluronic acid oligosaccharide modified redox-responsive mesoporous silica nanoparticles for targeted drug delivery.  


A redox-responsive delivery system based on colloidal mesoporous silica (CMS) has been developed, in which 6-mercaptopurine (6-MP) was conjugated to vehicles by cleavable disulfide bonds. The oligosaccharide of hyaluronic acid (oHA) was modified on the surface of CMS by disulfide bonds as a targeting ligand and was able to increase the stability and biocompatibility of CMS under physiological conditions. In vitro release studies indicated that the cumulative release of 6-MP was less than 3% in the absence of glutathione (GSH), and reached nearly 80% within 2 h in the presence of 3 mM GSH. Confocal microscopy and fluorescence-activated cell sorter (FACS) methods were used to evaluate the cellular uptake performance of fluorescein isothiocyanate (FITC) labeled CMS, with and without oHA modification. The CMS-SS-oHA exhibited a higher cellular uptake performance via CD44 receptor-mediated endocytosis in HCT-116 (CD44 receptor-positive) cells than in NIH-3T3 (CD44 receptor-negative) cells. 6-MP loaded CMS-SS-oHA exhibited greater cytotoxicity against HCT-116 cells than NIH-3T3 cells due to the enhanced cell uptake behavior of CMS-SS-oHA. This study provides a novel strategy to covalently link bioactive drug and targeting ligand to the interiors and exteriors of mesoporous silica to construct a stimulus-responsive targeted drug delivery system. PMID:25311422

Zhao, Qinfu; Geng, Hongjian; Wang, Ying; Gao, Yikun; Huang, Jiahao; Wang, Yan; Zhang, Jinghai; Wang, Siling



Urokinase Plasminogen Activator System Targeted Delivery of Nanobins as a Novel Ovarian Cancer Therapeutics  

PubMed Central

The urokinase system is overexpressed in epithelial ovarian cancer (OvCa) cells and is expressed at low levels in normal cells. To develop a platform for intracellular and targeted delivery of therapeutics in OvCa, we conjugated urokinase plasminogen activator (uPA) antibodies to liposomal nanobins. The arsenic trioxide loaded nanobins had favorable physicochemical properties and the ability to bind specifically to uPA. Confocal microscopy showed that the uPA targeted nanobins were internalized by OvCa cells, while both ICP-MS and FACS analyses confirmed >4-fold higher uptake of targeted nanobins when compared to untargeted nanobins. In a co-culture assay, the targeted nanobins showed efficient uptake in OvCa cells but not in the normal primary omental mesothelial cells. Moreover, this uptake could be blocked by either down-regulating uPA receptor expression in the OvCa cells using shRNA or by competition with free uPA or uPA antibody. In proof-of-concept experiments, mice bearing orthotopic ovarian tumors showed a greater reduction in tumor burden when treated with targeted nanobins than with untargeted nanobins (47% versus 27%; p<0.001). The targeted nanobins more effectively inhibited tumor cell growth both in vitro and in vivo compared to untargeted nanobins, inducing caspase-mediated apoptosis and impairing stem cell marker, ALDH1A1, expression. Ex vivo fluorescence imaging of tumors and organs corroborated these results, showing preferential localization of the targeted nanobins to the tumor. These findings suggest that uPA targeted nanobins capable of specifically and efficiently delivering payloads to cancer cells could serve as the foundation for a new targeted cancer therapy utilizing protease receptors. PMID:24061648

Zhang, Yilin; Kenny, Hilary A.; Swindell, Elden P.; Mitra, Anirban K.; Hankins, Patrick L.; Ahn, Richard W.; Gwin, Katja; Mazar, Andrew P.; O’Halloran, Thomas V.; Lengyel, Ernst



Odorranalectin Is a Small Peptide Lectin with Potential for Drug Delivery and Targeting  

PubMed Central

Background Lectins are sugar-binding proteins that specifically recognize sugar complexes. Based on the specificity of protein–sugar interactions, different lectins could be used as carrier molecules to target drugs specifically to different cells which express different glycan arrays. In spite of lectin's interesting biological potential for drug targeting and delivery, a potential disadvantage of natural lectins may be large size molecules that results in immunogenicity and toxicity. Smaller peptides which can mimic the function of lectins are promising candidates for drug targeting. Principal Findings Small peptide with lectin-like behavior was screened from amphibian skin secretions and its structure and function were studied by NMR, NMR-titration, SPR and mutant analysis. A lectin-like peptide named odorranalectin was identified from skin secretions of Odorrana grahami. It was composed of 17 aa with a sequence of YASPKCFRYPNGVLACT. L-fucose could specifically inhibit the haemagglutination induced by odorranalectin. 125I-odorranalectin was stable in mice plasma. In experimental mouse models, odorranalectin was proved to mainly conjugate to liver, spleen and lung after i.v. administration. Odorranalectin showed extremely low toxicity and immunogenicity in mice. The small size and single disulfide bridge of odorranalectin make it easy to manipulate for developing as a drug targeting system. The cyclic peptide of odorranalectin disclosed by solution NMR study adopts a ?-turn conformation stabilized by one intramolecular disulfide bond between Cys6-Cys16 and three hydrogen bonds between Phe7-Ala15, Tyr9-Val13, Tyr9-Gly12. Residues K5, C6, F7, C16 and T17 consist of the binding site of L-fucose on odorranalectin determined by NMR titration and mutant analysis. The structure of odorranalectin in bound form is more stable than in free form. Conclusion These findings identify the smallest lectin so far, and show the application potential of odorranalectin for drug delivery and targeting. It also disclosed a new strategy of amphibian anti-infection. PMID:18584053

Xu, Xueqing; Yang, Hailong; Wu, Bingxian; Wang, Yipeng; Zhu, Jianhua; Lai, Ren; Jiang, Xinguo; Lin, Donghai; Prescott, Mark C.; Rees, Huw H.



Design of an integrated hardware interface for AOSLO image capture and cone-targeted stimulus delivery  

PubMed Central

We demonstrate an integrated FPGA solution to project highly stabilized, aberration-corrected stimuli directly onto the retina by means of real-time retinal image motion signals in combination with high speed modulation of a scanning laser. By reducing the latency between target location prediction and stimulus delivery, the stimulus location accuracy, in a subject with good fixation, is improved to 0.15 arcminutes from 0.26 arcminutes in our earlier solution. We also demonstrate the new FPGA solution is capable of delivering stabilized large stimulus pattern (up to 256x256 pixels) to the retina. PMID:20721171

Yang, Qiang; Arathorn, David W.; Tiruveedhula, Pavan; Vogel, Curtis R.; Roorda, Austin



Synthetic Nano-Low Density Lipoprotein as Targeted Drug DeliveryVehicle for Glioblastoma Multiforme  

SciTech Connect

This paper discribes a synthetic low density lipoprotein(LDL) made by complexing a 29 amino acid that consists of a lipid bindingdomain and the LDL receptor binding domain with a lipid microemulsion.The nano-LDL particles were intermdiate in size between LDL and HDL andbound to LDL receptors on GBM brain tumor cells. Synthetic nano-LDLuptake by GBM cells was LDL receptor specific and dependent on cellreceptor number. It is suggested that these synthetic particles can serveas a delivery vehicle for hydophobic anti-tumor drugs by targeting theLDL receptor.

Nikanjam, Mina; Blakely, Eleanor A.; Bjornstad, Kathleen A.; Shu,Xiao; Budinger, Thomas F.; Forte, Trudy M.



Neuropathy-Inducing Effects of Eribulin Mesylate Versus Paclitaxel in Mice with Preexisting Neuropathy  

PubMed Central

Eribulin mesylate (E7389, INN:eribulin mesilate Halaven®) is a non-taxane microtubule dynamics inhibitor currently in clinical use for advanced breast cancer. Other microtubule-targeting agents for breast cancer, including paclitaxel and ixabepilone, display a common treatment dose-limiting toxicity of peripheral neuropathy (PN). In an earlier study, we found eribulin mesylate had a lower propensity to induce PN in mice than either paclitaxel or ixabepilone. In the current study, we compared additional PN induced by paclitaxel versus eribulin mesylate when administered to mice with preexisting paclitaxel-induced PN. Initially, paclitaxel at 0.75 × its maximum tolerated dose (MTD; 22.5 mg/kg) was given on a Q2Dx3 regimen for 2 weeks. The second chemotherapy was 0.5 MTD eribulin mesylate (0.875 mg/kg) or paclitaxel (15 mg/kg) on a similar regimen, starting 2 weeks after the first. Initial paclitaxel treatment produced significant decreases in caudal nerve conduction velocity (NCV; averaging 19.5 ± 1 and 22.2 ± 1.3 %, p < 0.001) and amplitude (averaging 53.2 ± 2.6 and 72.4 ± 2.1 %, p < 0.001) versus vehicle when measured 24 h or 2 weeks after dosing cessation, respectively. Additional 0.5 MTD paclitaxel further reduced caudal NCV and amplitude relative to immediately before initiation of the second regimen (by 11 ± 2.1 and 59.2 ± 5 %, p < 0.01, respectively). In contrast, 0.5 MTD eribulin mesylate caused no further decrease in caudal NCV. In conclusion, unlike additional paclitaxel treatment, eribulin mesylate administered to mice with preexisting paclitaxel-induced PN had limited additional deleterious effects at 6 weeks. These preclinical data suggest that eribulin mesylate may have reduced tendency to exacerbate preexisting paclitaxel-induced PN in clinical settings. PMID:23637052

Wozniak, Krystyna M.; Wu, Ying; Farah, Mohamed H.; Littlefield, Bruce A.; Nomoto, Kenichi



Neuropathy-inducing effects of eribulin mesylate versus paclitaxel in mice with preexisting neuropathy.  


Eribulin mesylate (E7389, INN:eribulin mesilate Halaven(®)) is a non-taxane microtubule dynamics inhibitor currently in clinical use for advanced breast cancer. Other microtubule-targeting agents for breast cancer, including paclitaxel and ixabepilone, display a common treatment dose-limiting toxicity of peripheral neuropathy (PN). In an earlier study, we found eribulin mesylate had a lower propensity to induce PN in mice than either paclitaxel or ixabepilone. In the current study, we compared additional PN induced by paclitaxel versus eribulin mesylate when administered to mice with preexisting paclitaxel-induced PN. Initially, paclitaxel at 0.75 × its maximum tolerated dose (MTD; 22.5 mg/kg) was given on a Q2Dx3 regimen for 2 weeks. The second chemotherapy was 0.5 MTD eribulin mesylate (0.875 mg/kg) or paclitaxel (15 mg/kg) on a similar regimen, starting 2 weeks after the first. Initial paclitaxel treatment produced significant decreases in caudal nerve conduction velocity (NCV; averaging 19.5 ± 1 and 22.2 ± 1.3 %, p < 0.001) and amplitude (averaging 53.2 ± 2.6 and 72.4 ± 2.1 %, p < 0.001) versus vehicle when measured 24 h or 2 weeks after dosing cessation, respectively. Additional 0.5 MTD paclitaxel further reduced caudal NCV and amplitude relative to immediately before initiation of the second regimen (by 11 ± 2.1 and 59.2 ± 5 %, p < 0.01, respectively). In contrast, 0.5 MTD eribulin mesylate caused no further decrease in caudal NCV. In conclusion, unlike additional paclitaxel treatment, eribulin mesylate administered to mice with preexisting paclitaxel-induced PN had limited additional deleterious effects at 6 weeks. These preclinical data suggest that eribulin mesylate may have reduced tendency to exacerbate preexisting paclitaxel-induced PN in clinical settings. PMID:23637052

Wozniak, Krystyna M; Wu, Ying; Farah, Mohamed H; Littlefield, Bruce A; Nomoto, Kenichi; Slusher, Barbara S



AAV-Mediated Delivery of Zinc Finger Nucleases Targeting Hepatitis B Virus Inhibits Active Replication  

PubMed Central

Despite an existing effective vaccine, hepatitis B virus (HBV) remains a major public health concern. There are effective suppressive therapies for HBV, but they remain expensive and inaccessible to many, and not all patients respond well. Furthermore, HBV can persist as genomic covalently closed circular DNA (cccDNA) that remains in hepatocytes even during otherwise effective therapy and facilitates rebound in patients after treatment has stopped. Therefore, the need for an effective treatment that targets active and persistent HBV infections remains. As a novel approach to treat HBV, we have targeted the HBV genome for disruption to prevent viral reactivation and replication. We generated 3 zinc finger nucleases (ZFNs) that target sequences within the HBV polymerase, core and X genes. Upon the formation of ZFN-induced DNA double strand breaks (DSB), imprecise repair by non-homologous end joining leads to mutations that inactivate HBV genes. We delivered HBV-specific ZFNs using self-complementary adeno-associated virus (scAAV) vectors and tested their anti-HBV activity in HepAD38 cells. HBV-ZFNs efficiently disrupted HBV target sites by inducing site-specific mutations. Cytotoxicity was seen with one of the ZFNs. scAAV-mediated delivery of a ZFN targeting HBV polymerase resulted in complete inhibition of HBV DNA replication and production of infectious HBV virions in HepAD38 cells. This effect was sustained for at least 2 weeks following only a single treatment. Furthermore, high specificity was observed for all ZFNs, as negligible off-target cleavage was seen via high-throughput sequencing of 7 closely matched potential off-target sites. These results show that HBV-targeted ZFNs can efficiently inhibit active HBV replication and suppress the cellular template for HBV persistence, making them promising candidates for eradication therapy. PMID:24827459

Weber, Nicholas D.; Stone, Daniel; Sedlak, Ruth Hall; De Silva Feelixge, Harshana S.; Roychoudhury, Pavitra; Schiffer, Joshua T.; Aubert, Martine; Jerome, Keith R.



Engineering RNA for Targeted siRNA Delivery and Medical Application  

PubMed Central

RNA engineering for nanotechnology and medical applications is an exciting emerging research field. RNA has intrinsically defined features on the nanometer scale and is a particularly interesting candidate for such applications due to its amazing diversity, flexibility and versatility in structure and function. Specifically, the current use of siRNA to silence target genes involved in disease has generated much excitement in the scientific community. The intrinsic ability to sequence-specifically down-regulate gene expression in a temporally- and spatially-controlled fashion has led to heightened interest and rapid development of siRNA-based therapeutics. Though methods for gene silencing with high efficacy and specificity have been achieved in vitro, the effective delivery of nucleic acids to specific cells in vivo has been a hurdle for RNA therapeutics. This review covers different RNA-based approaches for diagnosis, prevention and treatment of human disease, with a focus on the latest developments of nonviral carriers of siRNA for delivery in vivo. The applications and challenges of siRNA therapy, as well as potential solutions to these problems, the approaches for using phi29 pRNA-based vectors as polyvalent vehicles for specific delivery of siRNA, ribozymes, drugs or other therapeutic agents to specific cells for therapy will also be addressed. PMID:20230868

Guo, Peixuan; Coban, Oana; Snead, Nick; Trebley, Joe; Hoeprich, Steve; Guo, Songchuan; Shu, Yi



PEI-derivatized fullerene drug delivery using folate as a homing device targeting to tumor.  


Fullerene (C60) has shown great potential in drug delivery. In this study, firstly, amine-functionalized C60 (C60-NH(2)) was achieved by introducing ethylenediamine onto the surface of C60, and then PEI-derivatized C60 (C60-PEI) was performed via a cationic polymerization of aziridine on the surface of C60-NH(2); FT-IR and TGA results verified the structure of water-soluble C60-PEI. C60-PEI was encapsulated with folic acid (FA) through an amide linker, and then docetaxel (DTX) was conjugated to C60-PEI-FA and obtained a drug delivery system, C60-PEI-FA/DTX. Compared with free DTX, the tumor targeting drug delivery could efficiently cross cell membranes, lead to more apoptosis and afford higher antitumor efficacy in a cultured PC3 cells in vitro. Furthermore, compared with free DTX in an in vivo murine tumor model, C60-PEI-FA/DTX afforded higher antitumor efficacy without obvious toxic effects to normal organs owing to its prolonged blood circulation and 7.5-fold higher DTX uptake of tumor, demonstrating that C60-PEI-FA/DTX may be promising for high treatment efficacy with minimal side effects in future therapy. PMID:23069706

Shi, Jinjin; Zhang, Hongling; Wang, Lei; Li, Lulu; Wang, Honghong; Wang, Zhenzhen; Li, Zhi; Chen, Chengqun; Hou, Lin; Zhang, Chaofeng; Zhang, Zhenzhong



A novel in situ gel for sustained drug delivery and targeting.  


The objective of this study was to develop a novel chitosan-glyceryl monooleate (GMO) in situ gel system for sustained drug delivery and targeting. The delivery system consisted of 3% (w/v) chitosan and 3% (w/v) GMO in 0.33M citric acid. In situ gel was formed at a biological pH. In vitro release studies were conducted in Sorensen's phosphate buffer (pH 7.4) and drugs were analyzed either by HPLC or spectrophotometry. Characterization of the gel included the effect of cross-linker, determination of diffusion coefficient and water uptake by thermogravimetric analysis (TGA). Mucoadhesive property of the gel was evaluated in vitro using an EZ-Tester. Incorporation of a cross-linker (glutaraldehyde) retarded the rate and extent of drug release. The in vitro release can further be sustained by replacing the free drug with drug-encapsulated microspheres. Drug release from the gel followed a matrix diffusion controlled mechanism. Inclusion of GMO enhanced the mucoadhesive property of chitosan by three- to sevenfold. This novel in situ gel system can be useful in the sustained delivery of drugs via oral as well as parenteral routes. PMID:15113617

Ganguly, Sudipta; Dash, Alekha K



Biomaterials-based nanofiber scaffold: targeted and controlled carrier for cell and drug delivery.  


Abstract Nanofiber scaffold formulations (diameter less than 1000?nm) were successfully used to deliver the drug/cell/gene into the body organs through different routes for an effective treatment of various diseases. Various fabrication methods like drawing, template synthesis, fiber-mesh, phase separation, fiber-bonding, self-assembly, melt-blown, and electrospinning are successfully used for fabrication of nanofibers. These formulations are widely used in various fields such as tissue engineering, drug delivery, cosmetics, as filter media, protective clothing, wound dressing, homeostatic, sensor devices, etc. The present review gives a detailed account on the need of the nanofiber scaffold formulation development along with the biomaterials and techniques implemented for fabrication of the same against innumerable diseases. At present, there is a huge extent of research being performed worldwide on all aspects of biomolecules delivery. The unique characteristics of nanofibers such as higher loading efficiency, superior mechanical performance (stiffness and tensile strength), controlled release behavior, and excellent stability helps in the delivery of plasmid DNA, large protein drugs, genetic materials, and autologous stem-cell to the target site in the future. PMID:25539071

Garg, Tarun; Rath, Goutam; Goyal, Amit K



Synthesis of Bisethylnorspermine Lipid Prodrug as Gene Delivery Vector Targeting Polyamine Metabolism in Breast Cancer  

PubMed Central

Progress in the development of nonviral gene delivery vectors continues to be hampered by low transfection activity and toxicity. Here we proposed to develop a lipid prodrug based on a polyamine analogue bisethylnorspermine (BSP) that can function dually as gene delivery vector and, after intracellular degradation, as active anticancer agent targeting dysregulated polyamine metabolism. We synthesized a prodrug of BSP (LS-BSP) capable of intracellular release of BSP using thiolytically sensitive dithiobenzyl carbamate linker. Biodegradability of LS-BSP contributed to decreased toxicity compared with nondegradable control L-BSP. BSP showed a strong synergistic enhancement of cytotoxic activity of TNF-related apoptosis-inducing ligand (TRAIL) in human breast cancer cells. Decreased enhancement of TRAIL activity was observed for LS-BSP when compared with BSP. LS-BSP formed complexes with plasmid DNA and mediated transfection activity comparable to DOTAP and L-BSP. Our results show that BSP-based vectors are promising candidates for combination drug/gene delivery. PMID:22545813

Dong, Yanmei; Zhu, Yu; Li, Jing; Zhou, Qing-Hui; Wu, Chao; Oupický, David



Potential biomarkers for paclitaxel sensitivity in hypopharynx cancer cell.  


Paclitaxel has been proved to be active in treatment and larynx preservation of HNSCC, however, the fact that about 20-40% patients do not respond to paclitaxel makes it urgent to figure out the biomarkers for paclitaxel-based treatment in Hypopharynx cancer (HPC) patients to improve the therapy effect. In this work, Fadu cells, treated or untreated with low dose of paclitaxel for 24 h, were applied to DNA microarray chips. The differential expression in mRNAs and miRs was analyzed and the network between expression-altered mRNAs and miRs was constructed. Differentially expressed genes were mainly enriched in superpathway of cholesterol biosynthesis (ACAT2, MSMO1, LSS, FDFT1 and FDPS etc.), complement system (C3, C1R, C1S, CFR and CFB etc.), interferon signaling (IFIT1, IFIT3, IFITM1 and MX1 etc.), mTOR signaling (MRAS, PRKAA2, PLD1, RND3 and EIF4A1 etc.) and IGF1 signaling (MRAS, IGFBP7, JUN and FOS etc.), most of these pathways are implicated in tumorigenesis or chemotherapy resistance. The first three pathways were predicted to be suppressed, while the last two pathways were predicted to be induced by paclitaxel, suggesting the combination therapy with mTOR inhibition and paclitaxel might be better than single one. The dramatically expression-altered miRs were miR-112, miR-7, miR-1304, miR-222*, miR-29b-1* (these five miRs were upregulated) and miR-210 (downregulated). The 26 putative target genes mediated by the 6 miRs were figured out and the miR-gene network was constructed. Furthermore, immunoblotting assay showed that ERK signaling in Fadu cells was active by low dose of paclitaxel but repressed by high dose of paclitaxel. Collectively, our data would provide potential biomarkers and therapeutic targets for paclitaxel-based therapy in HPC patients. PMID:24294361

Xu, Cheng-Zhi; Shi, Run-Jie; Chen, Dong; Sun, Yi-Yuan; Wu, Qing-Wei; Wang, Tao; Wang, Pei-Hua



Mito-DCA: a mitochondria targeted molecular scaffold for efficacious delivery of metabolic modulator dichloroacetate.  


Tumor growth is fueled by the use of glycolysis, which normal cells use only in the scarcity of oxygen. Glycolysis makes tumor cells resistant to normal death processes. Targeting this unique tumor metabolism can provide an alternative strategy to selectively destroy the tumor, leaving normal tissue unharmed. The orphan drug dichloroacetate (DCA) is a mitochondrial kinase inhibitor that has the ability to show such characteristics. However, its molecular form shows poor uptake and bioavailability and limited ability to reach its target mitochondria. Here, we describe a targeted molecular scaffold for construction of a multiple DCA loaded compound, Mito-DCA, with three orders of magnitude enhanced potency and cancer cell specificity compared to DCA. Incorporation of a lipophilic triphenylphosphonium cation through a biodegradable linker in Mito-DCA allowed for mitochondria targeting. Mito-DCA did not show any significant metabolic effects toward normal cells but tumor cells with dysfunctional mitochondria were affected by Mito-DCA, which caused a switch from glycolysis to glucose oxidation and subsequent cell death via apoptosis. Effective delivery of DCA to the mitochondria resulted in significant reduction in lactate levels and played important roles in modulating dendritic cell (DC) phenotype evidenced by secretion of interleukin-12 from DCs upon activation with tumor antigens from Mito-DCA treated cancer cells. Targeting mitochondrial metabolic inhibitors to the mitochondria could lead to induction of an efficient antitumor immune response, thus introducing the concept of combining glycolysis inhibition with immune system to destroy tumor. PMID:24617941

Pathak, Rakesh K; Marrache, Sean; Harn, Donald A; Dhar, Shanta



A novel hydrolysis-resistant lipophilic folate derivative enables stable delivery of targeted liposomes in vivo  

PubMed Central

Instability of targeting ligand is a roadblock towards successful development of folate targeted liposomes. Folate ligands have been linked to polyethylene glycol (PEG) and cholesterol by an amide bond to form folate-CONH-PEG-CONH-Cholesterol (F-CONH-PEG-CONH-Chol), which is subject to hydrolysis. To increase the stability of folate ligands and promote the long circulation and targeting effects, we synthesized a chemically stable lipophilic folate derivative, folate-CONH-PEG-NH-Cholesterol (F-CONH-PEG-NH-Chol), where the amide bond was replaced by a C-N bond, to deliver liposomal doxorubicin (Dox). Its physical stability, cellular uptake, cellular toxicity, pharmacokinetics, distribution, anti-tumor efficacy, and cardiac toxicity were investigated. Our results indicate that F-CONH-PEG-NH-Chol conjugated liposomes are taken up selectively by folate receptor-positive HeLa and KB cells. Compared with F-CONH-PEG-CONH-Chol with two carbonate linkages, F-CONH-PEG-NH-Chol better retained its drug entrapment efficiency and folate receptor-targeting activity during prolonged circulation. F-CONH-PEG-NH-Chol thus represents a physically stable and effective ligand for delivering folate receptor-targeted liposomes, with prolonged circulation time and efficient tissue distribution, as well as higher efficacy and less cardiac toxicity. Collectively, these results suggest that this novel conjugate can serve as a promising derivative for the delivery of anti-tumor therapeutic agents. PMID:25302024

Huang, Yifei; Yang, Tan; Zhang, Wendian; Lu, Yao; Ye, Peng; Yang, Guang; Li, Bin; Qi, Shibo; Liu, Yong; He, Xingxing; Lee, Robert J; Xu, Chuanrui; Xiang, Guangya



Novel tumor-targeting, self-assembling peptide nanofiber as a carrier for effective curcumin delivery  

PubMed Central

The poor aqueous solubility and low bioavailability of curcumin restrict its clinical application for cancer treatment. In this study, a novel tumor-targeting nanofiber carrier was developed to improve the solubility and tumor-targeting ability of curcumin using a self-assembled Nap-GFFYG-RGD peptide. The morphologies of the peptide nanofiber and the curcumin-encapsulated nanofiber were visualized by transmission electron microscopy. The tumor-targeting activity of the curcumin-encapsulated Nap-GFFYG-RGD peptide nanofiber (f-RGD-Cur) was studied in vitro and in vivo, using Nap-GFFYG-RGE peptide nanofiber (f-RGE-Cur) as the control. Curcumin was encapsulated into the peptide nanofiber, which had a diameter of approximately 10–20 nm. Curcumin showed sustained-release behavior from the nanofibers in vitro. f-RGD-Cur showed much higher cellular uptake in ?v?3 integrin-positive HepG2 liver carcinoma cells than did non-targeted f-RGE-Cur, thereby leading to significantly higher cytotoxicity. Ex vivo studies further demonstrated that curcumin could accumulate markedly in mouse tumors after administration of f-RGD-Cur via the tail vein. These results indicate that Nap-GFFYG-RGD peptide self-assembled nanofibers are a promising hydrophobic drug delivery system for targeted treatment of cancer. PMID:24399876

Liu, Jianfeng; Liu, Jinjian; Xu, Hongyan; Zhang, Yumin; Chu, Liping; Liu, Qingfen; Song, Naling; Yang, Cuihong



Insights into EPR effect versus lectin-mediated targeted delivery: biodegradable polycarbonate micellar nanoparticles with and without galactose surface decoration.  


Polymeric micelles with and without galactose are synthesized to study liver targeting ability in an orthotopic HCC rat model. Micelles with galactose accumulate more in the healthy liver tissue instead of HCC, while micelles without galactose amass in HCC by the EPR effect. These micelles show great potential as drug delivery carriers to target either the liver or HCC. PMID:25091699

Ebrahim Attia, Amalina Binte; Oh, Pamela; Yang, Chuan; Tan, Jeremy Pang Kern; Rao, Nithya; Hedrick, James L; Yang, Yi Yan; Ge, Ruowen



Targeted Drug Delivery to the Peripheral Nervous System using Gene Therapy  

PubMed Central

Gene transfer to target delivery of neurotrophic factors to the primary sensory afferent for treatment of polyneuropathy, or of inhibitory neurotransmitters for relief of chronic pain, offers the possibility of a highly selective targeted release of bioactive molecules within the nervous system. Preclinical studies with non-replicating herpes simplex virus (HSV)-based vectors injected into the skin to transduce neurons in the dorsal root ganglion have demonstrated efficacy in reducing-pain related behaviors in animal models of inflammatory pain, neuropathic pain, and pain caused by cancer, and in preventing progression of sensory neuropathy caused by toxins, chemotherapeutic drugs or resulting from diabetes. Successful completion of the first phase 1 clinical trial of HSV-mediated gene transfer in patients with intractable pain from cancer has set the stage for further clinical trials of this approach. PMID:22565023

Wolfe, Darren; Mata, Marina; Fink, David J.



Receptor-targeted liposome-peptide nanocomplexes for siRNA delivery.  


RNA interference induced by double-stranded, small interfering RNA (siRNA) molecules has attracted great attention as a genetic therapeutic approach. Despite major advances in this field, new nanoparticle formulations are required for in vivo delivery of siRNA, particularly for tissue-specific delivery of siRNA reagents. We have developed and optimized LYR nanocomplex formulations for siRNA delivery that consist of a liposome (DOTMA/DOPE; L) and a targeting peptide (K??GACYGLPHKFCG; Y) which self-assemble on mixing at optimal ratios with siRNA (R). Biophysical measurements indicated that LYR nanocomplexes were strongly cationic, mainly spherical particles of less than 100 nm. These formulations packaged and protected siRNA on incubation with RNAseA with >90% intact siRNA recovery. In addition, intact siRNA was recovered from LYRs upon heparin treatment. A critical synergy was observed between the lipid and peptide components for LYR particle stability and transfection efficiency. To evaluate targeting, transfections were compared with non-targeted formulations containing K?? with no targeting ligand. Gene knockdown efficiencies with targeted formulations were more than two-fold better in all cell lines tested (p < 0.01). LYR formulations with liposomes containing DOTMA, which has an 18-carbon (C18) alkyl tail, were significantly better in silencing than formulations containing cationic lipids with shorter alkyl tails. LYRs with siRNA against endogenous luciferase and GAPDH were successful in silencing these genes in 3 cell lines (1HAEo- human airway epithelial, B104 rat neuroblastoma, Neuro2A-Luc mouse neuroblastoma) in vitro with 80% efficiency, similar in efficiency to Lipofectamine 2000. Confocal microscopy analysis with LYRs containing fluorescently labelled siRNA (Cy3) showed that the siRNA was located in the perinuclear region of the cytoplasm, where the RNA-induced silencing complex (RISC) is likely to be found. The LYR formulations may have applications for the further development of siRNA-based therapeutics. PMID:21624650

Tagalakis, Aristides D; He, Lin; Saraiva, Luisa; Gustafsson, Kenth T; Hart, Stephen L



Targeted delivery of peptide-conjugated biocompatible gold nanoparticles into cancer cell nucleus  

NASA Astrophysics Data System (ADS)

Nucleus remains a significant target for nanoparticles with diagnostic and therapeutic applications because both genetic information of the cell and transcription machinery reside there. Novel therapeutic strategies (for example, gene therapy), enabled by safe and efficient delivery of nanoparticles and drug molecules into the nucleus, are heralded by many as the ultimate treatment for severe and intractable diseases. However, most nanomaterials and macromolecules are incapable of reaching the cell nucleus on their own, because of biological barriers carefully honed by evolution including cellular membrane and nuclear envelope. In this paper, we have demonstrated an approach of fabrication of biocompatible gold nanoparticle (Au NP)-based vehicles which can entering into cancer cell nucleus by modifying Au NPs with both PEG 5000 and two different peptides (RGD and nuclear localization signal (NLS) peptide). The Au NPs used were fabricated via femtosecond laser ablation of Au bulk target in deionized water. The Au NPs produced by this method provide chemical free, virgin surface, which allows us to carry out "Sequential Conjugation" to modify their surface with PEG 5000, RGD, and NLS. "Sequential Conjugation" described in this presentation is very critical for the fabrication of Au NP-based vehicles capable of entering into cancer cell nucleus as it enables the engineering and tuning surface chemistries of Au NPs by independently adjusting amounts of PEG and peptides bound onto surface of Au NPs so as to maximize their nuclear targeting performance and biocompatibility regarding the cell line of interest. Both optical microscopy and transmission electron microscopy (TEM) are used to confirm the in vitro targeted nuclear delivery of peptide-conjugated biocompatible Au NPs by showing their presence in the cancer cell nucleus.

Qian, Wei; Curry, Taeyjuana; Che, Yong; Kopelman, Raoul



MRI-Visible Micellar Nanomedicine for Targeted Drug Delivery to Lung Cancer Cells  

PubMed Central

Polymeric micelles are emerging as a highly integrated nanoplatform for cancer targeting, drug delivery and tumor imaging applications. In this study, we describe a multifunctional micelle (MFM) system that is encoded with a lung cancer-targeting peptide (LCP), and encapsulated with superparamagnetic iron oxide (SPIO) and doxorubicin (Doxo) for MR imaging and therapeutic delivery, respectively. The LCP-encoded MFM showed significantly increased ?v?6-dependent cell targeting in H2009 lung cancer cells over a scrambled peptide (SP)-encoded MFM control as well as in an ?v?6-negative H460 cell control. 3H-Labeled MFM nanoparticles were used to quantify the time- and dose-dependent cell uptake of MFM nanoparticles with different peptide encoding (LCP vs SP) and surface densities (20% and 40%) in H2009 cells. LCP functionalization of the micelle surface increased uptake of the MFM by more than 3-fold compared to the SP control. These results were confirmed by confocal laser scanning microscopy, which further demonstrated the successful Doxo release from MFM and accumulation in the nucleus. SPIO clustering inside the micelle core resulted in high T2 relaxivity (>400 Fe mM?1 s?1) of the resulting MFM nanoparticles. T2-weighted MRI images showed clear contrast differences between H2009 cells incubated with LCP-encoded MFM over the SP-encoded MFM control. An ATP activity assay showed increased cytotoxicity of LCP-encoded MFM over SP-encoded MFM in H2009 cells (IC50 values were 28.3 ± 6.4 nM and 73.6 ± 6.3 nM, respectively; p < 0.005). The integrated diagnostic and therapeutic design of MFM nanomedicine potentially allows for image-guided, target-specific treatment of lung cancer. PMID:19708690

Guthi, Jagadeesh Setti; Yang, Su-Geun; Huang, Gang; Li, Shunzi; Khemtong, Chalermchai; Kessinger, Chase W.; Peyton, Michael; Minna, John D.; Brown, Kathlynn C.; Gao, Jinming



Water-soluble polymers for targeted drug delivery to human squamous carcinoma of head and neck.  


Human squamous cell carcinoma of the head and neck (SCCHN) is characterized by over expression of a tumor cell surface-specific receptor namely Hsp47/CBP2 that makes it a favorable candidate for targeted delivery of anticancer drugs. Several synthetic peptides have been identified as effective ligands for binding to CBP2. The purpose of this study is to investigate the potential of water-soluble N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-doxorubicin (Dox) conjugates containing a Hsp47/CBP2 binding peptide sequence, namely WHYPWFQNWAMA for targeted delivery to SCCHN. An HPMA copolymer containing Dox and CBP2 targeting peptide conjugated via lysosomally degradable glycylphenylalanylleucylglycine (GFLG) spacer was synthesized by free radical precipitation copolymerization. A control polymer without targeting moiety was also synthesized. The conjugates were characterized for drug content, peptide content, molecular weight and molecular weight distribution. The uptake of polymeric conjugates by both drug resistant and drug sensitive SCCHN cells were determined in vitro by flow cytometry using FACS scan analysis. Cytotoxicity of the conjugates towards drug sensitive as well as multidrug resistant SCCHN cells were evaluated by a clonal survival assay and compared to free Dox. The cytotoxicity of the free peptide was similarly evaluated. The internalization and subcellular fate of the conjugates in drug sensitive SCCHN cells was monitored using confocal microscopy. The new targetable copolymer contained 0.16 mmole peptide/g polymer. Studies on drug sensitive SCCHN cells demonstrated lesser uptake of both targeted and non-targeted conjugates compared to free Dox suggesting a slower endocytic mechanism of uptake for the conjugates as opposed to rapid diffusion of free Dox. At higher Dox equivalent concentrations (>20 microM) the targeted conjugate showed significantly higher uptake (p < or = 0.028) than the non-targeted conjugate. The uptake of the targeted conjugate was inhibited in the presence of an anti Hsp47 antibody suggesting the involvement of active receptor mediated endocytosis in cell entry of the conjugate. Compared to free Dox, the targeted and non-targeted conjugates caused marginally lower inhibition (p < or = 0.01) of the drug sensitive SCCHN cells. In contrast, the same conjugates showed significantly higher uptake (p < or = 0.004) by drug resistant SCCHN cells and caused significantly higher inhibition (p < or = 0.02) of drug resistant SCCHN cells when compared to free Dox. Results suggest that the polymeric conjugates were able to overcome drug resistance. Confocal microscopy studies demonstrated the uptake of the polymeric conjugates, followed by internalization, intralysosomal localization and subsequent release of Dox. HPMA copolymer-Dox-peptide conjugates targeted to SCCHN cells were able to overcome drug resistance and increase efficacy in vitro. The results suggest that targetable polymeric conjugates have potential to improve systemic head and neck cancer chemotherapy by increasing tumor localization and reducing dose-limiting toxicity. PMID:16036307

Nan, Anjan; Ghandehari, Hamidreza; Hebert, Carla; Siavash, Hessam; Nikitakis, Nikolaos; Reynolds, Mark; Sauk, John J



Immuno-LipoTRAIL: Targeted delivery of TRAIL-functionalized liposomal nanoparticles.  


The TNF-related apoptosis-inducing ligand (TRAIL) is a powerful inducer of apoptosis in tumor cells; however, clinical studies with recombinant soluble TRAIL were rather disappointing. Here, we developed TRAIL-functionalized liposomes (LipoTRAIL, LT) to mimic membrane-displayed TRAIL for efficient activation of death receptors DR4 and DR5 and enhanced induction of apoptosis, which were combined with an anti-EGFR single-chain Fv fragment (scFv) for targeted delivery to EGFR-positive tumor cells. These immuno-LipoTRAILs (ILTs) bound specifically to EGFR-expressing cells (Colo205) and exhibited increased cytotoxicity compared with that of nontargeted LTs. Compared to that of the soluble TRAIL, the plasma half-life of the functionalized liposomes was strongly extended, and increased antitumor activity of LT and ILT was demonstrated in a xenograft tumor model. Thus, we established a multifunctional liposomal TRAIL formulation (ILT) with improved pharmacokinetic and pharmacodynamic behavior, characterized by targeted delivery and increased induction of apoptosis due to multivalent TRAIL presentation. PMID:24766622

Seifert, Oliver; Pollak, Nadine; Nusser, Anja; Steiniger, Frank; Rüger, Ronny; Pfizenmaier, Klaus; Kontermann, Roland E



Maximizing gene delivery efficiencies of cationic helical polypeptides via balanced membrane penetration and cellular targeting.  


The application of non-viral gene delivery vectors is often accompanied with the poor correlation between transfection efficiency and the safety profiles of vectors. Vectors with high transfection efficiencies often suffer from high toxicities, making it unlikely to improve their efficiencies by increasing the DNA dosage. In the current study, we developed a ternary complex system which consisted of a highly membrane-active cationic helical polypeptide (PVBLG-8), a low-toxic, membrane-inactive cationic helical polypeptide (PVBLG-7) capable of mediating mannose receptor targeting, and DNA. The PVBLG-7 moiety notably enhanced the cellular uptake and transfection efficiency of PVBLG-8 in a variety of mannose receptor-expressing cell types (HeLa, COS-7, and Raw 264.7), while it did not compromise the membrane permeability of PVBLG-8 or bring additional cytotoxicities. Because of the simplicity and adjustability of the self-assembly approach, optimal formulations of the ternary complexes with a proper balance between membrane activity and targeting capability were easily identified in each specific cell type. The optimal ternary complexes displayed desired cell tolerability and markedly outperformed the PVBLG-8/DNA binary complexes as well as commercial reagent Lipofectamine™ 2000 in terms of transfection efficiency. This study therefore provides an effective and facile strategy to overcome the efficiency-toxicity poor correlation of non-viral vectors, which contributes insights into the design strategy of effective and safe non-viral gene delivery vectors. PMID:24211080

Zheng, Nan; Yin, Lichen; Song, Ziyuan; Ma, Liang; Tang, Haoyu; Gabrielson, Nathan P; Lu, Hua; Cheng, Jianjun



Formulation, Evaluation and Optimization of Pectin- Bora Rice Beads for Colon Targeted Drug Delivery System  

PubMed Central

Purpose: The purpose of this research was to established new polysaccharide for the colon targeted drug delivery system, its formulation and in vitro and in vivo evaluation. Methods: Microspheres containing pectin and bora rice were prepared by ionotropic gelation technique using zinc acetate as cross linking agent and model drug used was glipizide. A 32 full factorial design was employed to study the effect of independent variables, polymer to drug ratio (A), and concentration of cross linking agent (B) on dependent variables, particle size, swelling index, drug entrapment efficiency and percentage drug release. Results: Results of trial batches indicated that polymer to drug ratio and concentration of cross linking agent affects characteristics of beads. Beads were discrete, spherical and free flowing. Beads exhibited small particle size and showed higher percentage of drug entrapment efficiency. The optimized batch P2 exhibited satisfactory drug entrapment efficiency 68% and drug release was also controlled for more than 24 hours. The polymer to drug ratio had a more significant effect on the dependent variables. In vivo gamma scintigraphy study of optimized pectin-bora rice beads demonstrated degradation of beads whenever they reached to the colon. Conclusion: Bora rice is potential polysaccharide for colon targeted drug delivery system. PMID:24511481

Ramteke, Kuldeep Hemraj; Nath, Lilakant



Green synthesis of pullulan stabilized gold nanoparticles for cancer targeted drug delivery  

NASA Astrophysics Data System (ADS)

The aim of this study was to synthesize green chemistry based gold nanoparticles using liver specific biopolymer and to develop a liver cancer targeted drug delivery system with enhanced efficacy and minimal side effects. Pullulan stabilized gold nanoparticles (PAuNPs) were coupled with 5-Fluorouracil (5-Fu) and folic acid (Fa) which could be used as a tool for targeted drug delivery and imaging of cancer. The toxicity of 5-Fu, 5-Fu adsorbed gold nanoparticles (5-Fu@AuNPs), Fa-coupled 5-Fu adsorbed gold nanoparticles (5-Fu@AuNPs-Fa), was studied using zebrafish embryo as an in vivo model. The in vitro cytotoxicity of free 5-Fu, 5-Fu@AuNPs, 5-Fu@AuNPs-Fa against HepG2 cells was studied and found that the amount of 5-Fu required to achieve 50% of growth of inhibition (Ic50) was much lower in 5-Fu@AuNP-Fa than in free 5-Fu, 5-Fu@AuNPs. The in vivo biodistribution of PAuNPs showed that higher amount of gold had been accumulated in liver (54.42 ± 5.96 ?g) than in other organs.

Ganeshkumar, Moorthy; Ponrasu, Thangavel; Raja, Modhugoor Devendiran; Subamekala, Muthaiya Kannappan; Suguna, Lonchin



Nanotechnology in the targeted drug delivery for bone diseases and bone regeneration  

PubMed Central

Nanotechnology is a vigorous research area and one of its important applications is in biomedical sciences. Among biomedical applications, targeted drug delivery is one of the most extensively studied subjects. Nanostructured particles and scaffolds have been widely studied for increasing treatment efficacy and specificity of present treatment approaches. Similarly, this technique has been used for treating bone diseases including bone regeneration. In this review, we have summarized and highlighted the recent advancement of nanostructured particles and scaffolds for the treatment of cancer bone metastasis, osteosarcoma, bone infections and inflammatory diseases, osteoarthritis, as well as for bone regeneration. Nanoparticles used to deliver deoxyribonucleic acid and ribonucleic acid molecules to specific bone sites for gene therapies are also included. The investigation of the implications of nanoparticles in bone diseases have just begun, and has already shown some promising potential. Further studies have to be conducted, aimed specifically at assessing targeted delivery and bioactive scaffolds to further improve their efficacy before they can be used clinically. PMID:23836972

Gu, Wenyi; Wu, Chengtie; Chen, Jiezhong; Xiao, Yin



Glucose-conjugated chitosan nanoparticles for targeted drug delivery and their specific interaction with tumor cells  

NASA Astrophysics Data System (ADS)

A novel targeted drug delivery system, glucose-conjugated chitosan nanoparticles (GCNPs), was developed for specific recognition and interaction with glucose transporters (Gluts) over-expressed by tumor cells. GC was synthesized by using succinic acid as a linker between glucosamine and chitosan (CS), and successful synthesis was confirmed by NMR and elemental analysis. GCNPs were prepared by ionic crosslinking method, and characterized in terms of morphology, size, and zeta potential. The optimally prepared nanoparticles showed spherical shapes with an average particle size of (187.9 ± 3.8) nm and a zeta potential of (- 15.43 ± 0.31) mV. The GCNPs showed negligible cytotoxicity to mouse embryo fibroblast and 4T1 cells. Doxorubicin (DOX) could be efficiently entrapped into GCNPs, with a loading capacity and encapsulation efficiency of 20.11% and 64.81%, respectively. DOX-loaded nanoparticles exhibited sustained-release behavior in phosphate buffered saline (pH 7.4). In vitro cellular uptake studies showed that the GCNPs had better endocytosis ability than CSNPs, and the antitumor activity of DOX/GCNPs was 4-5 times effectiveness in 4T1 cell killing than that of DOX/CSNPs. All the results demonstrate that nanoparticles decorated with glucose have specific interactions with cancer cells via the recognition between glucose and Gluts. Therefore, Gluts-targeted GCNPs may be promising delivery agents in cancer therapies.

Li, Jing; Ma, Fang-Kui; Dang, Qi-Feng; Liang, Xing-Guo; Chen, Xi-Guang



P-glycoprotein trafficking as a therapeutic target to optimize CNS drug delivery  

PubMed Central

The primary function of the blood-brain barrier (BBB) /neurovascular unit is to protect the CNS from potentially harmful xenobiotic substances and maintain CNS homeostasis. Restricted access to the CNS is maintained via a combination of tight junction proteins as well as a variety of efflux and influx transporters that limits the transcellular and paracellular movement of solutes. Of the transporters identified at the BBB, P-glycoprotein (P-gp) has emerged as the transporter that is the greatest obstacle to effective CNS drug delivery. In this chapter we provide data to support intracellular protein trafficking of P-gp within cerebral capillary microvessels as a potential target for improved drug delivery. We show that pain induced changes in P-gp trafficking are associated with changes in P-gp’s association with caveolin-1, a key scaffolding/trafficking protein that co-localizes with P-gp at the luminal membrane of brain microvessels. Changes in co-localization with the phosphorylated and non-phosphorylated forms of caveolin-1, by pain, are accompanied by dynamic changes in the distribution, relocalization and activation of P-gp “pools” between microvascular endothelial cell subcellular compartments. Since redox sensitive processes may be involved in signaling disassembly of higher order structures of P-gp, we feel that manipulating redox signaling, via specific protein targeting at the BBB, may protect disulfide bond integrity of P-gp reservoirs and control trafficking to the membrane surface providing improved CNS drug delivery. The advantage of therapeutic drug “relocalization” of a protein is that the physiological impact can be modified, temporarily or long term, despite pathology-induced changes in gene transcription. PMID:25307213

Davis, Thomas P.; Sanchez-Covarubias, Lucy; Tome, Margaret E.



Delivery of CdiA nuclease toxins into target cells during contact-dependent growth inhibition.  


Bacterial contact-dependent growth inhibition (CDI) is mediated by the CdiB/CdiA family of two-partner secretion proteins. CDI systems deploy a variety of distinct toxins, which are contained within the polymorphic C-terminal region (CdiA-CT) of CdiA proteins. Several CdiA-CTs are nucleases, suggesting that the toxins are transported into the target cell cytoplasm to interact with their substrates. To analyze CdiA transfer to target bacteria, we used the CDI system of uropathogenic Escherichia coli 536 (UPEC536) as a model. Antibodies recognizing the amino- and carboxyl-termini of CdiA(UPEC536) were used to visualize transfer of CdiA from CDI(UPEC536+) inhibitor cells to target cells using fluorescence microscopy. The results indicate that the entire CdiA(UPEC536) protein is deposited onto the surface of target bacteria. CdiA(UPEC536) transfer to bamA101 mutants is reduced, consistent with low expression of the CDI receptor BamA on these cells. Notably, our results indicate that the C-terminal CdiA-CT toxin region of CdiA(UPEC536) is translocated into target cells, but the N-terminal region remains at the cell surface based on protease sensitivity. These results suggest that the CdiA-CT toxin domain is cleaved from CdiA(UPEC536) prior to translocation. Delivery of a heterologous Dickeya dadantii CdiA-CT toxin, which has DNase activity, was also visualized. Following incubation with CDI(+) inhibitor cells targets became anucleate, showing that the D.dadantii CdiA-CT was delivered intracellularly. Together, these results demonstrate that diverse CDI toxins are efficiently translocated across target cell envelopes. PMID:23469034

Webb, Julia S; Nikolakakis, Kiel C; Willett, Julia L E; Aoki, Stephanie K; Hayes, Christopher S; Low, David A



Paclitaxel (Taxol) in breast cancer.  


Paclitaxel (Taxol) is a diterpine plant compound that was isolated initially from the bark of the western yew tree, Taxus brevifolia, but can now be produced by semisynthesis from a renewable source. Paclitaxel is the first new agent in the past decade to have confirmed single agent activity in breast cancer in excess of 50%. A 28% response rate has been reported in doxorubicin-refractory patients. Ongoing studies include attempts to combine paclitaxel with other drugs used for breast cancer treatment and with radiation. PMID:7908664

Arbuck, S G; Dorr, A; Friedman, M A



Nanotechnology-based drug delivery systems.  


Nanoparticles hold tremendous potential as an effective drug delivery system. In this review we discussed recent developments in nanotechnology for drug delivery. To overcome the problems of gene and drug delivery, nanotechnology has gained interest in recent years. Nanosystems with different compositions and biological properties have been extensively investigated for drug and gene delivery applications. To achieve efficient drug delivery it is important to understand the interactions of nanomaterials with the biological environment, targeting cell-surface receptors, drug release, multiple drug administration, stability of therapeutic agents and molecular mechanisms of cell signalling involved in pathobiology of the disease under consideration. Several anti-cancer drugs including paclitaxel, doxorubicin, 5-fluorouracil and dexamethasone have been successfully formulated using nanomaterials. Quantom dots, chitosan, Polylactic/glycolic acid (PLGA) and PLGA-based nanoparticles have also been used for in vitro RNAi delivery. Brain cancer is one of the most difficult malignancies to detect and treat mainly because of the difficulty in getting imaging and therapeutic agents past the blood-brain barrier and into the brain. Anti-cancer drugs such as loperamide and doxorubicin bound to nanomaterials have been shown to cross the intact blood-brain barrier and released at therapeutic concentrations in the brain. The use of nanomaterials including peptide-based nanotubes to target the vascular endothelial growth factor (VEGF) receptor and cell adhesion molecules like integrins, cadherins and selectins, is a new approach to control disease progression. PMID:18053152

Suri, Sarabjeet Singh; Fenniri, Hicham; Singh, Baljit



Herbal and polymeric approaches for liver-targeting drug delivery: novel strategies and their significance.  


Abstract The liver is a vital organ present in vertebrates, which performs many functions including detoxification, protein synthesis and production of various bio-chemicals which are very important for digestion. A large number of serious liver disorders affect millions of people worldwide which are very difficult to treat properly despite many efforts. There are several factors which are responsible for liver injuries, include plants (Crotalaria Senecio Heliotropium Symphytum officinale), drugs (analgesic and antibiotics), industrial toxins (mercury and lead), water, alcohol and so on. Herbal medicinal preparations can be used for the treatment of a large number of human liver disorders like cirrhosis, hepatitis, carcinomas, etc. Indian Medicinal Practitioner's Co-operative pharmacy and Stores (IMPCPS) approved herbal-based systems (Unani, Siddha and Ayurveda) for the treatment of various chronic liver disorders. Different types of the receptors are found on the surface of hepatocytes, Kupffer cell, hepatic stellate cell and sinusoidal endothelial cells, etc., which can be used for achieving liver targeting. These receptors bind to different types of ligands (galactosylated, lactobionic acid, asialofetuin, etc.) which can be used in the formulation to achieve targeted delivery of the drug. Various novel particulate approaches (liposomes, niosomes, nanoparticles, micelles, nanosuspensions, etc.) can be used to enhance the targeting efficiency of systems to receptors found on the surface of different cells present in the liver. In this review, we focused on the status of liver targeting via herbal and nanotechnology inspired formulation approaches. PMID:25101832

Rohilla, Raman; Garg, Tarun; Goyal, Amit K; Rath, Goutam



Targeted drug delivery to tumor vasculature by a carbohydrate mimetic peptide  

PubMed Central

Although numerous carbohydrates play significant roles in mammalian cells, carbohydrate-based drug discovery has not been explored due to the technical difficulty of chemically synthesizing complex carbohydrate structures. Previously, we identified a series of carbohydrate mimetic peptides and found that a 7-mer peptide, designated I-peptide, inhibits hematogenous carbohydrate-dependent cancer cell colonization. During analysis of the endothelial surface receptor for I-peptide, we found that I-peptide bound to annexin 1 (Anxa1). Because Anxa1 is a highly specific tumor vasculature surface marker, we hypothesized that an I-peptide-like peptide could target anticancer drugs to the tumor vasculature. This study identifies IFLLWQR peptide, designated IF7, as homing to tumors. When synthetic IF7 peptide was conjugated to fluorescent Alexa 488 (A488) and injected intravenously into tumor-bearing mice, IF7-A488 targeted tumors within minutes. IF7 conjugated to the potent anticancer drug SN-38 and injected intravenously into nude mice carrying human colon HCT116 tumors efficiently suppressed tumor growth at low dosages with no apparent side effects. These results suggest that IF7 serves as an efficient drug delivery vehicle by targeting Anxa1 expressed on the surface of tumor vasculature. Given its extremely specific tumor-targeting activity, IF7 may represent a clinically relevant vehicle for anticancer drugs. PMID:22114188

Hatakeyama, Shingo; Sugihara, Kazuhiro; Shibata, Toshiaki K.; Nakayama, Jun; Akama, Tomoya O.; Tamura, Naoaki; Wong, Shuk-Man; Bobkov, Andrey A.; Takano, Yutaka; Ohyama, Chikara; Fukuda, Minoru; Fukuda, Michiko N.



Preparation of Quantum Dot/Drug Nanoparticle Formulations for Traceable Targeted Delivery and Therapy  

PubMed Central

Quantum dots (QDs) are luminescent nanocrystals with rich surface chemistry and unique optical properties that make them useful as probes or carriers for traceable targeted delivery and therapy applications. QDs can be functionalized to target specific cells or tissues by conjugating them with targeting ligands. Recent advancement in making biocompatible QD formulations has made these nanocrystals suitable for in vivo applications. This review provides an overview of the preparation of QDs and their use as probes or carriers for traceable, targeted therapy of diseases in vitro and in vivo. More specifically, recent advances in the integration of QDs with drug formulations for therapy and their potential toxicity in vitro and in vivo are highlighted. The current findings and challenges for optimizing QD/drug formulations with respect to optimal size and stability, short-term and long-term toxicity, and in vivo applications are described. Lastly, we attempt to predict key trends in QD/drug formulation development over the next few years and highlight areas of therapy where their use may provide breakthrough results in the near future. PMID:22896770

Yong, Ken-Tye; Wang, Yucheng; Roy, Indrajit; Rui, Hu; Swihart, Mark T.; Law, Wing-Cheung; Kwak, Sang Kyu; Ye, Ling; Liu, Jianwei; Mahajan, Supriya D.; Reynolds, Jessica L.



The targeted delivery of multicomponent cargos to cancer cells by nanoporous particle-supported lipid bilayers  

NASA Astrophysics Data System (ADS)

Encapsulation of drugs within nanocarriers that selectively target malignant cells promises to mitigate side effects of conventional chemotherapy and to enable delivery of the unique drug combinations needed for personalized medicine. To realize this potential, however, targeted nanocarriers must simultaneously overcome multiple challenges, including specificity, stability and a high capacity for disparate cargos. Here we report porous nanoparticle-supported lipid bilayers (protocells) that synergistically combine properties of liposomes and nanoporous particles. Protocells modified with a targeting peptide that binds to human hepatocellular carcinoma exhibit a 10,000-fold greater affinity for human hepatocellular carcinoma than for hepatocytes, endothelial cells or immune cells. Furthermore, protocells can be loaded with combinations of therapeutic (drugs, small interfering RNA and toxins) and diagnostic (quantum dots) agents and modified to promote endosomal escape and nuclear accumulation of selected cargos. The enormous capacity of the high-surface-area nanoporous core combined with the enhanced targeting efficacy enabled by the fluid supported lipid bilayer enable a single protocell loaded with a drug cocktail to kill a drug-resistant human hepatocellular carcinoma cell, representing a 106-fold improvement over comparable liposomes.

Ashley, Carlee E.; Carnes, Eric C.; Phillips, Genevieve K.; Padilla, David; Durfee, Paul N.; Brown, Page A.; Hanna, Tracey N.; Liu, Juewen; Phillips, Brandy; Carter, Mark B.; Carroll, Nick J.; Jiang, Xingmao; Dunphy, Darren R.; Willman, Cheryl L.; Petsev, Dimiter N.; Evans, Deborah G.; Parikh, Atul N.; Chackerian, Bryce; Wharton, Walker; Peabody, David S.; Brinker, C. Jeffrey



In Vivo Tumor Targeting and Image-Guided Drug Delivery with Antibody-Conjugated, Radiolabeled Mesoporous Silica Nanoparticles  

PubMed Central

Since the first use of biocompatible mesoporous silica (mSiO2) nanoparticles as drug delivery vehicles, in vivo tumor targeted imaging and enhanced anti-cancer drug delivery has remained a major challenge. In this work, we describe the development of functionalized mSiO2 nanoparticles for actively targeted positron emission tomography (PET) imaging and drug delivery in 4T1 murine breast tumor-bearing mice. Our structural design involves the synthesis, surface functionalization with thiol groups, PEGylation, TRC105 antibody (specific for CD105/endoglin) conjugation, and 64Cu-labeling of uniform 80 nm sized mSiO2 nanoparticles. Systematic in vivo tumor targeting studies clearly demonstrated that 64Cu-NOTA-mSiO2-PEG-TRC105 could accumulate prominently at the 4T1 tumor site via both the enhanced permeability and retention effect and TRC105-mediated binding to tumor vasculature CD105. As a proof-of-concept, we also demonstrated successful enhanced tumor targeted delivery of doxorubicin (DOX) in 4T1 tumor-bearing mice after intravenous injection of DOX-loaded NOTA-mSiO2-PEG-TRC105, which holds great potential for future image-guided drug delivery and targeted cancer therapy. PMID:24083623

Chen, Feng; Hong, Hao; Zhang, Yin; Valdovinos, Hector F.; Shi, Sixiang; Kwon, Glen S.; Theuer, Charles P.; Barnhart, Todd E.; Cai, Weibo



Targeted delivery of antibody-based therapeutic and imaging agents to CNS tumors: Crossing the blood-brain-barrier divide  

PubMed Central

Introduction Brain tumors are inherently difficult to treat in large part due to the cellular blood-brain barriers (BBB) that limit the delivery of therapeutics to the tumor tissue from the systemic circulation. Virtually no large-molecules, including antibody-based proteins, can penetrate the BBB. With antibodies fast becoming attractive ligands for highly specific molecular targeting to tumor antigens, a variety of methods are being investigated to enhance the access of these agents to intracranial tumors for imaging or therapeutic applications. Areas covered This review describes the characteristics of the BBB and the vasculature in brain tumors, described as the blood-brain tumor barrier (BBTB). Antibodies targeted to molecular markers of CNS tumors will be highlighted, and current strategies for enhancing the delivery of antibodies across these cellular barriers into the brain parenchyma to the tumor will be discussed. Non-invasive imaging approaches to assess BBB/BBTB permeability and/or antibody targeting will be presented as a means of guiding the optimal delivery of targeted agents to brain tumors. Expert Opinion Pre-clinical and clinical studies highlight the potential of several approaches in increasing brain tumor delivery across the blood-brain barrier divide. However, each carries its own risks and challenges. There is tremendous potential in using neuroimaging strategies to assist in understanding and defining the challenges to translating and optimizing molecularly-targeted antibody delivery to CNS tumors to improve clinical outcomes. PMID:23751126

Chacko, Ann-Marie; Li, Chunsheng; Pryma, Daniel A.; Brem, Steven; Coukos, George; Muzykantov, Vladimir R.



PR_b-targeted delivery of tumor necrosis factor-? by polymersomes for the treatment of prostate cancer  

Microsoft Academic Search

Targeted delivery of therapeutics is an active area of research with cancer being an important target because of the necessity for new and better cancer therapies. In this study we design and assess peptide functionalized polymer vesicles, or polymersomes, self assembled from poly(ethylene oxide)-b- poly(butadiene) (PEO-PBD) diblock copolymers for the treatment of prostate cancer. PR_b, a highly effective a5b1 targeting

Döne Demirgöz; Todd O. Pangburn; Kevin P. Davis; Sangwoo Lee; Frank S. Bates; Efrosini Kokkoli



Multifunctional quantum dot-polypeptide hybrid nanogel for targeted imaging and drug delivery  

NASA Astrophysics Data System (ADS)

A new type of multifunctional quantum dot (QD)-polypeptide hybrid nanogel with targeted imaging and drug delivery properties has been developed by metal-affinity driven self-assembly between artificial polypeptides and CdSe-ZnS core-shell QDs. On the surface of QDs, a tunable sandwich-like microstructure consisting of two hydrophobic layers and one hydrophilic layer between them was verified by capillary electrophoresis, transmission electron microscopy, and dynamic light scattering measurements. Hydrophobic and hydrophilic drugs can be simultaneously loaded in a QD-polypeptide nanogel. In vitro drug release of drug-loaded QD-polypeptide nanogels varies strongly with temperature, pH, and competitors. A drug-loaded QD-polypeptide nanogel with an arginine-glycine-aspartic acid (RGD) motif exhibited efficient receptor-mediated endocytosis in ?v?3 overexpressing HeLa cells but not in the control MCF-7 cells as analyzed by confocal microscopy and flow cytometry. In contrast, non-targeted QD-polypeptide nanogels revealed minimal binding and uptake in HeLa cells. Compared with the original QDs, the QD-polypeptide nanogels showed lower in vitro cytotoxicity for both HeLa cells and NIH 3T3 cells. Furthermore, the cytotoxicity of the targeted QD-polypeptide nanogel was lower for normal NIH 3T3 cells than that for HeLa cancer cells. These results demonstrate that the integration of imaging and drug delivery functions in a single QD-polypeptide nanogel has the potential for application in cancer diagnosis, imaging, and therapy.A new type of multifunctional quantum dot (QD)-polypeptide hybrid nanogel with targeted imaging and drug delivery properties has been developed by metal-affinity driven self-assembly between artificial polypeptides and CdSe-ZnS core-shell QDs. On the surface of QDs, a tunable sandwich-like microstructure consisting of two hydrophobic layers and one hydrophilic layer between them was verified by capillary electrophoresis, transmission electron microscopy, and dynamic light scattering measurements. Hydrophobic and hydrophilic drugs can be simultaneously loaded in a QD-polypeptide nanogel. In vitro drug release of drug-loaded QD-polypeptide nanogels varies strongly with temperature, pH, and competitors. A drug-loaded QD-polypeptide nanogel with an arginine-glycine-aspartic acid (RGD) motif exhibited efficient receptor-mediated endocytosis in ?v?3 overexpressing HeLa cells but not in the control MCF-7 cells as analyzed by confocal microscopy and flow cytometry. In contrast, non-targeted QD-polypeptide nanogels revealed minimal binding and uptake in HeLa cells. Compared with the original QDs, the QD-polypeptide nanogels showed lower in vitro cytotoxicity for both HeLa cells and NIH 3T3 cells. Furthermore, the cytotoxicity of the targeted QD-polypeptide nanogel was lower for normal NIH 3T3 cells than that for HeLa cancer cells. These results demonstrate that the integration of imaging and drug delivery functions in a single QD-polypeptide nanogel has the potential for application in cancer diagnosis, imaging, and therapy. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03058c

Yang, Jie; Yao, Ming-Hao; Wen, Lang; Song, Ji-Tao; Zhang, Ming-Zhen; Zhao, Yuan-Di; Liu, Bo



Preparation of irinotecan-loaded folate-targeted liposome for tumor targeting delivery and its antitumor activity.  


The purpose of this study was to investigate the in vivo distribution and antitumor activity of irinotecan (camptothecin (CPT)-11)-loaded folate-targeted liposome (F-Lip) in tumor-bearing mice following i.v. administration. Folate-poly(ethylene glycol)-distearoylphosphatidylcholine (FA-PEG-DSPE) was synthesized by amide reaction of DSPE-PEG-NH(2) and FA. F-Lip modified by FA-PEG-DSPE was prepared by an ammonium sulfate gradient. The mean particle size and entrapment efficiency of F-Lip with negative charge were 197.8 ± 4.58 nm and 91.39 ± 2.34 %, respectively. The distributions of CPT-11 and SN-38 in the tumor after i.v. administration of F-Lip, CPT-11-loaded liposomes (C-Lip), and CPT-11 injection (C-Inj) were far greater with the F-Lip group in comparison to the C-Inj and C-Lip, which might contribute to folate-meditated targeting uptake by the folate receptor on the surface of the tumor cells. The uptake of CPT-11 in the liver and rectum for two liposome groups were all markedly increased as compared to the C-Inj. Moreover, F-Lip exhibited a dose-dependent tumor growth inhibition and superior anticancer activity to C-Lip and C-Inj after i.v. administration. It also showed no significant body weight loss and much lower toxicity on the center immune organs. Therefore, F-Lip may be presented as potential candidates for tumor targeting drug delivery. PMID:22639238

Zhang, Ziqiang; Yao, Jing



Dual-layer surface coating of PLGA-based nanoparticles provides slow-release drug delivery to achieve metronomic therapy in a paclitaxel-resistant murine ovarian cancer model.  


Development of drug resistance is a central challenge to the treatment of ovarian cancer. Metronomic chemotherapy decreases the extent of drug-free periods, thereby hindering development of drug resistance. Intraperitoneal chemotherapy allows for treatment of tumors confined within the peritoneum, but achieving sustained tumor-localized chemotherapy remains difficult. We hypothesized that modulating the surface properties of poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles could enhance their drug retention ability and extend their release profile, thereby enabling metronomic, localized chemotherapy in vivo. Paclitaxel was encapsulated in particles coated with a layer of polydopamine and a subsequent layer of poly(ethylene glycol) (PEG). These particles achieved a 3.8-fold higher loading content compared to that of nanoparticles formulated from linear PLGA-PEG copolymers. In vitro release kinetic studies and in vivo drug distribution profiles demonstrate sustained release of paclitaxel. Although free drug conferred no survival advantage, low-dose intraperitoneal administration of paclitaxel-laden surface-coated nanoparticles to drug-resistant ovarian tumor-bearing mice resulted in significant survival benefits in the absence of any apparent systemic toxicity. PMID:25251833

Amoozgar, Zohreh; Wang, Lei; Brandstoetter, Tania; Wallis, Samuel S; Wilson, Erin M; Goldberg, Michael S



Probucol release from novel multicompartmental microcapsules for the oral targeted delivery in type 2 diabetes.  


In previous studies, we developed and characterised multicompartmental microcapsules as a platform for the targeted oral delivery of lipophilic drugs in type 2 diabetes (T2D). We also designed a new microencapsulated formulation of probucol-sodium alginate (PB-SA), with good structural properties and excipient compatibility. The aim of this study was to examine the stability and pH-dependent targeted release of the microcapsules at various pH values and different temperatures. Microencapsulation was carried out using a Büchi-based microencapsulating system developed in our laboratory. Using SA polymer, two formulations were prepared: empty SA microcapsules (SA, control) and loaded SA microcapsules (PB-SA, test), at a constant ratio (1:30), respectively. Microcapsules were examined for drug content, zeta potential, size, morphology and swelling characteristics and PB release characteristics at pH 1.5, 3, 6 and 7.8. The production yield and microencapsulation efficiency were also determined. PB-SA microcapsules had 2.6?±?0.25% PB content, and zeta potential of -66?±?1.6%, suggesting good stability. They showed spherical and uniform morphology and significantly higher swelling at pH 7.8 at both 25 and 37°C (p?targeted delivery with a multiphasic release pattern and with good stability and uniformity. However, the release of PB from the microcapsules was not controlled, suggesting uneven distribution of the drug within the microcapsules. PMID:25168450

Mooranian, Armin; Negrulj, Rebecca; Al-Sallami, Hesham S; Fang, Zhongxiang; Mikov, Momir; Golocorbin-Kon, Svetlana; Fakhoury, Marc; Watts, Gerald F; Matthews, Vance; Arfuso, Frank; Lambros, Amanda; Al-Salami, Hani



Target-specific delivery of doxorubicin to retinoblastoma using epithelial cell adhesion molecule aptamer  

PubMed Central

Purpose To study target-specific delivery of doxorubicin (Dox) using an RNA aptamer against epithelial cell adhesion molecule (EpCAM) in retinoblastoma (RB) cells. Methods The binding affinity of the EpCAM aptamer to RB primary tumor cells, Y79 and WERI-Rb1 cells, and Müller glial cell lines were evaluated with flow cytometry. Formation of physical conjugates of aptamer and Dox was monitored with spectrofluorimetry. Cellular uptake of aptamer-Dox conjugates was monitored through fluorescent microscopy. Drug efficacy was monitored with cell proliferation assay. Results The EpCAM aptamer (EpDT3) but not the scrambled aptamer (Scr-EpDT3) bound to RB tumor cells, the Y79 and WERI-Rb1 cells. However, the EpCAM aptamer and the scrambled aptamer did not bind to the noncancerous Müller glial cells. The chimeric EpCAM aptamer Dox conjugate (EpDT3-Dox) and the scrambled aptamer Dox conjugate (Scr-EpDT3-Dox) were synthesized and tested on the Y79, WERI-Rb1, and Müller glial cells. The targeted uptake of the EpDT3-Dox aptamer caused cytotoxicity in the Y79 and WERI-Rb1 cells but not in the Müller glial cells. There was no significant binding or consequent cytotoxicity by the Scr-EpDT3-Dox in either cell line. The EpCAM aptamer alone did not cause cytotoxicity in either cell line. Conclusions The results show that the EpCAM aptamer-Dox conjugate can selectively deliver the drug to the RB cells there by inhibiting cellular proliferation and not to the noncancerous Müller glial cells. As EpCAM is a cancer stem cell marker, this aptamer-based targeted drug delivery will prevent the undesired effects of non-specific drug activity and will kill cancer stem cells precisely in RB. PMID:23213278

Subramanian, Nithya; Raghunathan, Vaishnavi; Kanwar, Jagat R.; Kanwar, Rupinder K.; Elchuri, Sailaja V.; Khetan, Vikas



Targeted Cytosolic Delivery of Cell-Impermeable Compounds by Nanoparticle-Mediated, Light-Triggered Endosome Disruption  

PubMed Central

Nanoparticle (NP)-mediated drug delivery typically relies on cargo release to occur passively or in response to environmental stimuli. Here we present a delivery method based on light-activated disruption of intracellular vesicles after internalization of biofunctionalized mesoporous silica nanoparticles loaded with cargo. This method combines the power of targeted delivery with the spatiotemporal control of light activation. As an example, we delivered a cell-impermeable fluorescent compound exclusively to the cytosol of multidrug resistant cancer cells in a mixed population. PMID:20446663

Febvay, Sébastien; Marini, Davide M.; Belcher, Angela M.; Clapham, David E.



Superparamagnetic iron oxide nanoparticles (SPIONs)-loaded Trojan microparticles for targeted aerosol delivery to the lung.  


Targeted aerosol delivery to specific regions of the lung may improve therapeutic efficiency and minimise unwanted side effects. Targeted delivery could potentially be achieved with porous microparticles loaded with superparamagnetic iron oxide nanoparticles (SPIONs)-in combination with a target-directed magnetic gradient field. The aim of this study was to formulate and evaluate the aerodynamic properties of SPIONs-loaded Trojan microparticles after delivery from a dry powder inhaler. Microparticles made of SPIONs, PEG and hydroxypropyl-?-cyclodextrin (HP?CD) were formulated by spray drying and characterised by various physicochemical methods. Aerodynamic properties were evaluated using a next generation cascade impactor (NGI), with or without a magnet positioned at stage 2. Mixing appropriate proportions of SPIONs, PEG and HP?CD allowed Trojan microparticle to be formulated. These particles had a median geometric diameter of 2.8±0.3?m and were shown to be sensitive to the magnetic field induced by a magnet having a maximum energy product of 413.8kJ/m(3). However, these particles, characterised by a mass median aerodynamic diameter (MMAD) of 10.2±2.0?m, were considered to be not inhalable. The poor aerodynamic properties resulted from aggregation of the particles. The addition of (NH4)2CO3 and magnesium stearate (MgST) to the formulation improved the aerodynamic properties of the Trojan particles and resulted in a MMAD of 2.2±0.8?m. In the presence of a magnetic field on stage 2 of the NGI, the amount of particles deposited at this stage increased 4-fold from 4.8±0.7% to 19.5±3.3%. These Trojan particles appeared highly sensitive to the magnetic field and their deposition on most of the stages of the NGI was changed in the presence compared to the absence of the magnet. If loaded with a pharmaceutical active ingredient, these particles may be useful for treating localised lung disease such as cancer nodules or bacterial infectious foci. PMID:24055690

Tewes, Frederic; Ehrhardt, Carsten; Healy, Anne Marie



Enzyme/pH dual sensitive polymeric nanoparticles for targeted drug delivery to the inflamed colon.  


Novel nanoparticles whose drug release profiles are controlled by both enzyme and pH were prepared for the colon-specific drug delivery using a polymeric mixture of enzyme-sensitive azo-polyurethane and pH-sensitive Eudragit S100 (ES-Azo.pu). The enzyme/pH dual sensitive nanoparticles were designed to release a drug based on a two-fold approach which specifically aimed to target drug delivery to the inflamed colon while preventing the burst release of drugs in the stomach and small intestine. Single pH-sensitive (ES) and dual sensitive (ES-Azo.pu) nanoparticles were prepared using an oil-in-water emulsion solvent evaporation method and coumarin-6 (C-6) was used as a model drug. The successful formation of ES and ES-azo.pu nanoparticles that have 214 nm and 244 nm in mean particle size, respectively, was confirmed by scanning electron microscopy and qNano. ES nanoparticles showed almost 100% of burst drug release at pH 7.4, whereas ES-Azo.pu nanoparticles prevented the burst drug release at pH 7.4, followed by a sustained release phase thereafter. Furthermore, ES-Azo.pu nanoparticles exhibited enzyme-triggered drug release in the presence of rat cecal contents obtained from a rat model of colitis. An in vivo localization study in rat gastrointestinal tract demonstrated that ES-Azo.pu nanoparticles were selectively distributed in the inflamed colon, showing 5.5-fold higher C-6 than ES nanoparticles. In conclusion, the enzyme/pH dual sensitive nanoparticles presented in this study can serve as a promising strategy for colon-specific drug delivery against inflammatory bowel disease and other colon disorders. PMID:25266978

Naeem, Muhammad; Kim, Wooseong; Cao, Jiafu; Jung, Yunjin; Yoo, Jin-Wook



Photoactive metal carbonyl complexes as potential agents for targeted CO delivery.  


The surprising discovery of carbon monoxide (CO) as a signaling molecule in mammalian physiology has recently raised interest in this toxic gas among researchers in biochemical and pharmaceutical community. CO is endogenously produced mainly from catabolism of heme by the enzyme heme oxygenase (HO) and participates in a myriad of anti-inflammatory, anti-proliferative, and vasoregulatory pathways. In animal models, low doses of CO have exhibited beneficial effects in suppression of organ graft rejection and safeguarding the heart during reperfusion after cardiopulmonary bypass surgery. The salutary effects of CO have naturally drawn attention of the pharmaceutical industry for its use as a cytoprotective agent. Safety-related concerns of the use of this noxious gas have prompted research in the area of syntheses of CO-releasing molecules (CORMs) and to date, several metal carbonyls (metal complexes of CO) have been employed as CORMs in promoting prolonged (and safe) delivery of low doses of CO to cellular targets. Because many carbonyl complexes release CO upon illumination, investigators have recently began to explore the possibility of "controlled CO delivery" through the use of light. During the past few years, a number of photoactive CORMs or "photoCORMs" have been synthesized that release CO upon illumination with UV or visible light. The utility of these photoCORMs in CO delivery has also been confirmed. Novel design principles for isolation of photoCORMs have started to appear in recent reports. Scrutiny of the literature reveals the emergence of a new exciting area of drug development in such efforts. The potential of photoCORMs as CO-donating pharmaceuticals along with a brief overview of the physiological roles of CO is presented in this review. PMID:24287103

Gonzales, Margarita A; Mascharak, Pradip K



A lysosome-targeted drug delivery system based on sorbitol backbone towards efficient cancer therapy.  


A straightforward synthetic approach was adopted for the construction of a lysosome-targeted drug delivery system (TDDS) using sorbitol scaffold (Sor) linked to octa-guanidine and tetrapeptide GLPG, a peptide substrate of lysosomal cysteine protease, cathepsin B. The main objective was to efficiently deliver the potential anticancer drug, doxorubicin to the target sites, thereby minimizing dose-limiting toxicity. Three TDDS vectors were synthesized viz., DDS1: Sor-GLPG-Fl, DDS2: Sor-Fl (control) and DDS3: Sor-GLPGC-SMCC-Dox. Dox release from DDS3 in the presence of cathepsin B was studied by kinetics measurement based on the fluorescent property of Dox. The cytotoxicity of DDS1 was assessed and found to be non-toxic. Cellular internalization and colocalization studies of all the 3 systems were carried out by flow cytometry and confocal microscopy utilizing cathepsin B-expressing HeLa cells. DDS1 and DDS3 revealed significant localization within the lysosomes, in contrast to DDS2 (control). The doxorubicin-conjugated carrier, DDS3, demonstrated significant cytotoxic effect when compared to free Dox by MTT assay and also by flow cytometric analysis. The targeted approach with DDS3 is expected to be promising, because it is indicated to be advantageous over free Dox, which possesses dose-limiting toxicity, posing risk of injury to normal tissues. PMID:25062087

Maniganda, Santhi; Sankar, Vandana; Nair, Jyothi B; Raghu, K G; Maiti, Kaustabh K



Mechanisms and Implications of Dual-Acting Methotrexate in Folate-Targeted Nanotherapeutic Delivery  

PubMed Central

The rational design of a nanoplatform in drug delivery plays a crucial role in determining its targeting specificity and efficacy in vivo. A conventional approach relies on the surface conjugation of a nanometer-sized particle with two functionally distinct types of molecules, one as a targeting ligand, and the other as a therapeutic agent to be delivered to the diseased cell. However, an alternative simplified approach can be used, in which a single type of molecule displaying dual function as both a targeting ligand and therapeutic agent is conjugated to the nanoparticle. In this review, we evaluate the validity of this new strategy by using methotrexate, which displays multifunctional mechanisms of action. Methotrexate binds to the folate receptor, a surface biomarker frequently overexpressed in tumor cells, and also inhibits dihydrofolate reductase, an enzyme critical for cell survival and division. Thus we describe a series of fifth generation poly(amido amine) dendrimers conjugated with methotrexate, and discuss several lines of evidence supporting the efficacy of this new platform strategy based on surface plasmon resonance spectroscopy, enzyme activity assays, and cell-based studies with folate receptor (+) KB cancer cells. PMID:25590303

Wong, Pamela T.; Choi, Seok Ki



In Vivo Fluorescence Resonance Energy Transfer Imaging for Targeted Anti-Cancer Drug Delivery Kinetics  

NASA Astrophysics Data System (ADS)

We describe an approach for the evaluation of targeted anti-cancer drug delivery in vivo. The method emulates the drug release and activation process through acceptor release from a targeted donor-acceptor pair that exhibits fluorescence resonance energy transfer (FRET). In this case, folate targeting of the cancer cells is used - 40 % of all human cancers, including ovarian, lung, breast, kidney, brain and colon cancer, over-express folate receptors. We demonstrate the reconstruction of the spatially-dependent FRET parameters in a mouse model and in tissue phantoms. The FRET parameterization is incorporated into a source for a diffusion equation model for photon transport in tissue, in a variant of optical diffusion tomography (ODT) called FRET-ODT. In addition to the spatially-dependent tissue parameters in the diffusion model (absorption and diffusion coefficients), the FRET parameters (donor-acceptor distance and yield) are imaged as a function of position. Modulated light measurements are made with various laser excitation positions and a gated camera. More generally, our method provides a new vehicle for studying disease at the molecular level by imaging FRET parameters in deep tissue, and allows the nanometer FRET ruler to be utilized in deep tissue.

Webb, Kevin; Gaind, Vaibhav; Tsai, Hsiaorho; Bentz, Brian; Chelvam, Venkatesh; Low, Philip



Alkali reversal of psoralen cross-link for the targeted delivery of psoralen monoadduct lesion  

SciTech Connect

Psoralen intercalates into double-stranded DNA and photoreacts mainly with thymines to form monoadducts and interstrand cross-links. The authors used an oligonucleotide model to demonstrate a novel mechanism: the reversal of psoralen cross-links by base-catalyzed rearrangement at 90/sup 0/C (BCR). The BCR reaction is more efficient than the photoreversal reaction. They show that the BCR occurs predominantly on the furan side of a psoralen cross-link. The cleavage does not result in the breaking of the DNA backbone, and the thymine based freed from the cross-link by the cleavage reaction appears to be unmodified. Similarly, BCR of the furan-side monoadduct of psoralen removed the psoralen molecule and regenerated the unaltered native oligonucleotide. The pyrone-side psoralen monoadduct is relatively resistant to BCR. One can use BCR to perform efficient oligonucleotide-directed, site-specific delivery of a psoralen monoadduct. As a demonstration of this approach, they have hybridized a 19 base long oligonucleotide vehicle containing a furan-side psoralen monoadduct to a 56 base long complementary oligonucleotide target strand and formed a specific cross-link at the target site with 365-nm UV. Subsequent BCR released the oligonucleotide vehicle and deposited the psoralen at the target site.

Yeung, A.T.; Dinehart, W.J.; Jones, B.K.



Self-immolative polycations as gene delivery vectors and prodrugs targeting polyamine metabolism in cancer.  


Polycations are explored as carriers to deliver therapeutic nucleic acids. Polycations are conventionally pharmacological inert with the sole function of delivering therapeutic cargo. This study reports synthesis of a self-immolative polycation (DSS-BEN) based on a polyamine analogue drug N(1),N(11)-bisethylnorspermine (BENSpm). The polycation was designed to function dually as a gene delivery carrier and a prodrug targeting dysregulated polyamine metabolism in cancer. Using a combination of NMR and HPLC, we confirm that the self-immolative polycation undergoes intracellular degradation into the parent drug BENSpm. The released BENSpm depletes cellular levels of spermidine and spermine and upregulates polyamine catabolic enzymes spermine/spermidine N(1)-acetyltransferase (SSAT) and spermine oxidase (SMO). The synthesized polycations form polyplexes with DNA and facilitate efficient transfection. Taking advantage of the ability of BENSpm to sensitize cancer cells to TNF?-induced apoptosis, we show that DSS-BEN enhances the cell killing activity of TNF? gene therapy. The reported findings validate DSS-BEN as a dual-function delivery system that can deliver a therapeutic gene and improve the outcome of gene therapy as a result of the intracellular degradation of DSS-BEN to BENSpm and the subsequent beneficial effect of BENSpm on dysregulated polyamine metabolism in cancer. PMID:25153488

Zhu, Yu; Li, Jing; Kanvinde, Shrey; Lin, Zhiyi; Hazeldine, Stuart; Singh, Rakesh K; Oupický, David



Targeting Anticancer Drug Delivery to Pancreatic Cancer Cells Using a Fucose-Bound Nanoparticle Approach  

PubMed Central

Owing to its aggressiveness and the lack of effective therapies, pancreatic ductal adenocarcinoma has a dismal prognosis. New strategies to improve treatment and survival are therefore urgently required. Numerous fucosylated antigens in sera serve as tumor markers for cancer detection and evaluation of treatment efficacy. Increased expression of fucosyltransferases has also been reported for pancreatic cancer. These enzymes accelerate malignant transformation through fucosylation of sialylated precursors, suggesting a crucial requirement for fucose by pancreatic cancer cells. With this in mind, we developed fucose-bound nanoparticles as vehicles for delivery of anticancer drugs specifically to cancer cells. L-fucose-bound liposomes containing Cy5.5 or Cisplatin were effectively delivered into CA19-9 expressing pancreatic cancer cells. Excess L-fucose decreased the efficiency of Cy5.5 introduction by L-fucose-bound liposomes, suggesting L-fucose-receptor-mediated delivery. Intravenously injected L-fucose-bound liposomes carrying Cisplatin were successfully delivered to pancreatic cancer cells, mediating efficient tumor growth inhibition as well as prolonging survival in mouse xenograft models. This modality represents a new strategy for pancreatic cancer cell-targeting therapy. PMID:22808043

Yoshida, Makoto; Takimoto, Rishu; Murase, Kazuyuki; Sato, Yasushi; Hirakawa, Masahiro; Tamura, Fumito; Sato, Tsutomu; Iyama, Satoshi; Osuga, Takahiro; Miyanishi, Koji; Takada, Kohichi; Hayashi, Tsuyoshi; Kobune, Masayoshi; Kato, Junji



Targeting potassium channels for increasing delivery of imaging agents and therapeutics to brain tumors  

PubMed Central

Every year in the US, 20,000 new primary and nearly 200,000 metastatic brain tumor cases are reported. The cerebral microvessels/capillaries that form the blood–brain barrier not only protect the brain from toxic agents in the blood but also pose a significant hindrance to the delivery of small and large therapeutic molecules. Different strategies have been employed to circumvent the physiological barrier posed by blood–brain tumor barrier (BTB). Studies in our laboratory have identified significant differences in the expression levels of certain genes and proteins between normal and brain tumor capillary endothelial cells (ECs). In this study, we validated the non-invasive and clinically relevant dynamic contrast enhancing-magnetic resonance imaging (DCE-MRI) method with invasive, clinically irrelevant but highly accurate quantitative autoradiography method using rat glioma model. We also showed that DCE-MRI metric of tissue vessel perfusion-permeability is sensitive to changes in blood vessel permeability following administration of calcium-activated potassium (BKCa) channel activator NS-1619. Our results show that human gliomas and brain tumor ECs that overexpress BKCa channels can be targeted for increased BTB permeability for MRI enhancing agents to brain tumors. We conclude that monitoring the outcome of increased MRI enhancing agents’ delivery to microsatellites and leading tumor edges in glioma patients would lead to beneficial clinical outcome. PMID:23755013

Khaitan, Divya; Ningaraj, Nagendra S.



Preparation and characterization of magnetic gene vectors for targeting gene delivery  

NASA Astrophysics Data System (ADS)

The PEI-CMD-MNPs were successfully prepared by the surface modification of magnetic Fe3O4 nanoparticles with carboxymethyl dextran (CMD) and polyethyleneimine (PEI). The PEI-CMD-MNPs polyplexes exhibited a typical superparamagnetic behavior and were well stable over the entire range of pH and NaCl concentration. These PEI-CMD-MNPs were used as magnetic gene vectors for targeting gene delivery. The prepared MNPs at different surface modification stages were characterized using Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), field emissions canning electron microscopy (FE-SEM), powder X-ray diffraction (XRD) and dynamic laser light scattering (DLS) analysis. The magnetic properties were studied by vibrating sample magnetometer (VSM). To evaluate the performance of the magnetic nanoparticles as gene transfer vector, the PEI-CMD-MNPs were used to delivery green fluorescent protein (GFP) gene into BHK21 cells. The expression of GFP gene was detected by fluorescence microscope. DNA-PEI-CMD-MNPs polyplexes absorbed by the cells were also monitored by Magnetic resonance imaging (MRI). The transfection efficiency and gene expression efficiency of that transfected with a magnet were much higher than that of standard transfection.

Zheng, S. W.; Liu, G.; Hong, R. Y.; Li, H. Z.; Li, Y. G.; Wei, D. G.



Mannosylated Chitosan Nanoparticles for Delivery of Antisense Oligonucleotides for Macrophage Targeting  

PubMed Central

The therapeutic potential of antisense oligonucleotides (ASODN) is primarily dependent upon its safe and efficient delivery to specific cells overcoming degradation and maximizing cellular uptake in vivo. The present study focuses on designing mannosylated low molecular weight (LMW) chitosan nanoconstructs for safe ODNs delivery by macrophage targeting. Mannose groups were coupled with LMW chitosan and characterized spectroscopically. Mannosylated chitosan ODN nanoparticles (MCHODN NPs) were formulated by self-assembled method using various N/P ratio (moles of amine groups of MCH to phosphate moieties of ODNs) and characterized for gel retardation assay, physicochemical characteristics, cytotoxicity and transfection efficiency, and antisense assay. Complete complexation of MCH/ODN was achieved at charge ratio of 1:1 and above. On increasing the N/P ratio of MCH/ODN, particle size of the NPs decreased whereas zeta potential (ZV) increased. MCHODN NPs displayed much higher transfection efficiency into Raw 264.7 cells (bears mannose receptors) than Hela cells and no significant toxicity was observed at all MCH concentrations. Antisense assay revealed that reduction in lipopolysaccharide (LPS) induced serum TNF-? is due to antisense activity of TJU-2755 ODN (sequence complementary to 3?-UTR of TNF-?). These results suggest that MCHODN NPs are acceptable choice to improve transfection efficiency in vitro and in vivo. PMID:25057492

Asthana, Abhay; Kohli, Dharm Veer; Vyas, Suresh Prasad



Fabrication of high specificity hollow mesoporous silica nanoparticles assisted by Eudragit for targeted drug delivery.  


Hollow mesoporous silica nanoparticles (HMSNs) are one of the most promising carriers for effective drug delivery due to their large surface area, high volume for drug loading and excellent biocompatibility. However, the non-ionic surfactant templated HMSNs often have a broad size distribution and a defective mesoporous structure because of the difficulties involved in controlling the formation and organization of micelles for the growth of silica framework. In this paper, a novel "Eudragit assisted" strategy has been developed to fabricate HMSNs by utilising the Eudragit nanoparticles as cores and to assist in the self-assembly of micelle organisation. Highly dispersed mesoporous silica spheres with intact hollow interiors and through pores on the shell were fabricated. The HMSNs have a high surface area (670m(2)/g), small diameter (120nm) and uniform pore size (2.5nm) that facilitated the effective encapsulation of 5-fluorouracil within HMSNs, achieving a high loading capacity of 194.5mg(5-FU)/g(HMSNs). The HMSNs were non-cytotoxic to colorectal cancer cells SW480 and can be bioconjugated with Epidermal Growth Factor (EGF) for efficient and specific cell internalization. The high specificity and excellent targeting performance of EGF grafted HMSNs have demonstrated that they can become potential intracellular drug delivery vehicles for colorectal cancers via EGF-EGFR interaction. PMID:25617610

She, Xiaodong; Chen, Lijue; Velleman, Leonora; Li, Chengpeng; Zhu, Haijin; He, Canzhong; Wang, Tao; Shigdar, Sarah; Duan, Wei; Kong, Lingxue



Galactosylated Chitosan Oligosaccharide Nanoparticles for Hepatocellular Carcinoma Cell-Targeted Delivery of Adenosine Triphosphate  

PubMed Central

Nanoparticles composed of galactosylated chitosan oligosaccharide (Gal-CSO) and adenosine triphosphate (ATP) were prepared for hepatocellular carcinoma cell-specific uptake, and the characteristics of Gal-CSO/ATP nanoparticles were evaluated. CSO/ATP nanoparticles were prepared as a control. The average diameter and zeta potential of Gal-CSO/ATP nanoparticles were 51.03 ± 3.26 nm and 30.50 ± 1.25 mV, respectively, suggesting suitable properties for a drug delivery system. Subsequently, the cytotoxicity of Gal-CSO/ATP nanoparticles were examined by the methyl tetrazolium (MTT) assay, and the half maximal inhibitory concentration (IC50) values were calculated with HepG2 (human hepatocellular carcinoma cell line) cells. The results showed that the cytotoxic effect of nanoparticles on HepG2 cells was low. In the meantime, it was also found that the Gal-CSO/ATP nanoparticles could be uptaken by HepG2 cells, due to expression of the asialoglycoprotein receptor (ASGP-R) on their surfaces. The presented results indicate that the Gal-CSO nanoparticles might be very attractive to be used as an intracellular drug delivery carrier for hepatocellular carcinoma cell targeting, thus warranting further in vivo or clinical investigations. PMID:23899789

Zhu, Xiu Liang; Du, Yong Zhong; Yu, Ri Sheng; Liu, Ping; Shi, Dan; Chen, Ying; Wang, Ying; Huang, Fang Fang



Close-packed vesicles for diclofenac skin delivery and fibroblast targeting.  


Concentrated and interconnected penetration enhancer containing vesicles (PEVs) are proposed as carriers for dermal delivery of diclofenac. PEVs were prepared by using a commercial phosphatidylcholine mixture (180 mg/m) and transcutol in different amounts. Conventional liposomes were also prepared and tested as control. All vesicles showed a mean size ranging from 75 to 253 nm with fairly narrow size distribution, negative zeta potential value, and drug loading capacity between 48 and 70%. SWAXS studies showed that composition affected vesicle structure and morphology: 10 and 30% transcutol PEVs were unilamellar while liposomes and 20% transcutol PEVs were multilamellar. Rheological studies demonstrated that control liposomes and 10 and 30% transcutol containing PEVs behaved as Newtonian fluids while 20% transcutol containing PEVs showed a plastic behavior. Ex vivo (trans)dermal delivery experiments showed an improved skin deposition of diclofenac when PEVs were used. Vesicle toxicity and uptake of fibroblasts, target of inflammation treatment, were evaluated by MTT test and fluorescence microscopy. Control liposomes and PEVs were both able to interact and being internalized by the 3T3 fibroblasts at all time exposure tested. Furthermore, PEVs showed to be able to reduce the in vitro drug toxicity. PMID:23907049

Manca, Maria Letizia; Manconi, Maria; Falchi, Angela Maria; Castangia, Ines; Valenti, Donatella; Lampis, Sandrina; Fadda, Anna Maria



Mannosylated chitosan nanoparticles for delivery of antisense oligonucleotides for macrophage targeting.  


The therapeutic potential of antisense oligonucleotides (ASODN) is primarily dependent upon its safe and efficient delivery to specific cells overcoming degradation and maximizing cellular uptake in vivo. The present study focuses on designing mannosylated low molecular weight (LMW) chitosan nanoconstructs for safe ODNs delivery by macrophage targeting. Mannose groups were coupled with LMW chitosan and characterized spectroscopically. Mannosylated chitosan ODN nanoparticles (MCHODN NPs) were formulated by self-assembled method using various N/P ratio (moles of amine groups of MCH to phosphate moieties of ODNs) and characterized for gel retardation assay, physicochemical characteristics, cytotoxicity and transfection efficiency, and antisense assay. Complete complexation of MCH/ODN was achieved at charge ratio of 1:1 and above. On increasing the N/P ratio of MCH/ODN, particle size of the NPs decreased whereas zeta potential (ZV) increased. MCHODN NPs displayed much higher transfection efficiency into Raw 264.7 cells (bears mannose receptors) than Hela cells and no significant toxicity was observed at all MCH concentrations. Antisense assay revealed that reduction in lipopolysaccharide (LPS) induced serum TNF-? is due to antisense activity of TJU-2755 ODN (sequence complementary to 3'-UTR of TNF-?). These results suggest that MCHODN NPs are acceptable choice to improve transfection efficiency in vitro and in vivo. PMID:25057492

Asthana, Gyati Shilakari; Asthana, Abhay; Kohli, Dharm Veer; Vyas, Suresh Prasad



PMMA/polysaccharides nanofilm loaded with adenosine deaminase inhibitor for targeted anti-inflammatory drug delivery.  


A novel drug delivery vector, a free-standing polymeric ultrathin film (nanofilm) composed of PMMA and a polysaccharides multilayer, is presented. Chitosan and sodium alginate are alternatively deposited by spin-assisted LbL assembly onto a plasma-treated PMMA thin film. Hydrophobic anti-inflammatory drugs, an adenosine deaminase inhibitor (APP) and its fluorescent dansyl derivate (APP-Dns), are encapsulated inside the LbL multilayer using a simple casting deposition procedure. The resulting drug loaded nanofilm can be suspended in water upon dissolution of a PVA sacrificial layer. Morphological characterization of the nanofilm shows that PMMA/LbL nanofilms possess nanometric thickness (<200 nm) and very low surface roughness (1-2 nm for drug loaded nanofilms and <1 nm for blank nanofilm). Drug loaded films exhibit a diffusion controlled release mechanism following the Korsmayer-Peppas release model, confirmed by the fit of release data with a characteristic power law. Drug release is impaired through the PMMA layer, which acts effectively as a barrier for drug transport. This ultrathin polymer film can find application as a nanopatch for targeted inflammatory drug delivery to treat localized pathologies as inflammatory bowel disease. PMID:24073802

Redolfi Riva, Eugenio; Desii, Andrea; Sartini, Stefania; La Motta, Concettina; Mazzolai, Barbara; Mattoli, Virgilio



Antibody-targeted delivery of doxorubicin entrapped in sterically stabilized liposomes can eradicate lung cancer in mice.  


Cancer chemotherapy is limited by adverse side effects resulting from toxicities to normal tissues. Targeted delivery of drugs to diseased tissues in vivo would help to reduce these side effects. Liposomes containing lipid derivatives of polyethylene glycol have circulation times sufficiently long to allow for effective in vivo drug delivery. Polyethylene glycol liposomes, containing entrapped doxorubicin, targeted to KLN-205 squamous cell carcinoma of the lung by means of specific antibodies attached at the liposome surface were capable of reducing tumor burden to a high degree and eradicating tumor in a significant percentage of mice. PMID:8453612

Ahmad, I; Longenecker, M; Samuel, J; Allen, T M



Targeted Drug Delivery to the Brain by MRI-guided Focused Ultrasound  

NASA Astrophysics Data System (ADS)

The effect of focused ultrasound on the absorption of liposome-encapsulated doxorubicin in the brain was investigated. By applying focused ultrasound in the presence of microbubble ultrasound contrast agent, we achieved targeted drug delivery to the brain in vivo. Tissue drug concentrations in sonicated brain corresponded with cytotoxic levels measured in various human tumors and were significantly different from those measured in unexposed contralateral control samples (p ? 0.02). In addition, increased MR signal enhancement at the focal location on contrast-enhanced T1-weighted fast spin echo images correlated with increased penetration of doxorubicin into brain tissue (r = 0.85), indicating the potential of MRI to be used as an indicator of blood-brain barrier permeability during treatment. Further investigation is required to evaluate the efficacy of this technique and to optimize its parameters for clinical application.

Treat, Lisa Hsu; McDannold, Nathan; Vykhodtseva, Natalia; Zhang, Yongzhi; Tam, Karen; Hynynen, Kullervo



Targeted delivery of curcumin to tumors via PEG-derivatized FTS-based micellar system.  


Curcumin and S-trans, trans-farnesylthiosalicylic acid (FTS) are two promising anticancer agents. In this study, we demonstrated that the two agents exerted significant synergy in antitumor activity in various types of cancer cells with combination indices ranging from 0.46 to 0.98 (a value of less than unity indicates synergism). We have further shown that synergistic-targeted co-delivery of the two agents can be achieved via formulating curcumin in polyethylene glycol (PEG)-derivatized FTS-based nanomicellar system. Curcumin formulated in PEG-FTS micelles had small size of around 20 nm. The nanomicellar curcumin demonstrated enhanced cytotoxicity towards several cancer cell lines in vitro. Intravenous application of curcumin-loaded micelle (20 mg kg(-1) curcumin) led to a significantly more effective inhibition of tumor growth in a syngeneic mouse breast cancer model (4T1.2) than curcumin formulated in Cremophor/EL (P?

Chen, Yichao; Zhang, Xiaolan; Lu, Jianqin; Huang, Yixian; Li, Jiang; Li, Song



Targeted Delivery of Magnetic Cobalt Nanoparticles to the Eye Following Systemic Administration  

NASA Astrophysics Data System (ADS)

The eye offers a unique environment in the body to study progression and response to treatment of various ocular, vascular, and neurologic diseases as they occur in vivo. Due to its clear optical media, we can directly view blood vessels and nerve tissue, which often reflect the health of these tissues in the rest of the body. There are limitations to topical, periocular, or intraocular drug delivery that include access of the drug to the posterior segment of the eye and complications such as local scarring, hemorrhage, retinal detachment, cataract formation, or infection. The aim of this proof-of-concept study was to determine if systemically delivered magnetic cobalt nanoparticles (Co-MNP) could be directed to the eye of C57Bl mice via a unidirectional magnetic field. Both radioactive biodistribution studies and confocal imaging confirmed the increased presence of magnetic particles in the eye following magnetic targeting.

Dengler, Mirko; Saatchi, Katayoun; Dailey, James P.; Matsubara, Joanne; Mikelberg, Frederick S.; Häfeli, Urs O.; Yeung, Sonia N.



Engineered nanocrystal technology: in-vivo fate, targeting and applications in drug delivery.  


Formulation of nanocrystals is a robust approach which can improve delivery of poorly water soluble drugs, a challenge pharmaceutical industry has been facing since long. Large scale production of nanocrystals is done by techniques like precipitation, media milling and, high pressure homogenization. Application of appropriate stabilizers along with drying accords long term stability and commercial viability to nanocrystals. These can be administered through oral, parenteral, pulmonary, dermal and ocular routes showing their high therapeutic applicability. They serve to target drug molecules in specific regions through size manipulation and surface modification. This review dwells upon the in-vivo fate and varying applications in addition to the facets of drug nanocrystals stated above. PMID:24667572

Pawar, Vivek K; Singh, Yuvraj; Meher, Jaya Gopal; Gupta, Siddharth; Chourasia, Manish K



Multi-ligand nanoparticles for targeted drug delivery to the injured vascular wall  

NASA Astrophysics Data System (ADS)

Pathological conditions like coronary artery disease, acute myocardial infarction, stroke, and peripheral artery diseases as well as cardiovascular interventions used in the treatment of coronary artery diseases such as angioplasty and stenting damage/injure the blood vessel wall, leading to inflamed or activated endothelial cells that have been implicated in events leading to thrombosis, inflammation, and restenosis. Oral administration of anti-coagulant and anti-inflammatory drugs causes systemic toxicity, bleeding, patient incompliance, and inadequate amounts of drugs at the injured area. Though drug-eluting stents have shown therapeutic benefits, complications such as in-stent restenosis and late thrombosis still remain and are a cause for concern. Rapid growth in the field of nanotechnology and nanoscience in recent years has paved the way for new targeted and controlled drug delivery strategies. In this perspective, the development of biodegradable nanoparticles for targeted intracellular drug delivery to the inflamed endothelial cells may offer an improved avenue for treatment of cardiovascular diseases. The major objective of this research was to develop "novel multi-ligand nanoparticles," as drug carriers that can efficiently target and deliver therapeutic agents to the injured/inflamed vascular cells under dynamic flow conditions. Our approach mimics the natural binding ability of platelets to injured/activated endothelial cells through glycoprotein Ib (GPIb) bound to P-selectin expressed on inflamed endothelial cells and to the subendothelium through GPIb binding to von Willebrand factor (vWF) deposited onto the injured vascular wall. Our design also exploits the natural cell membrane translocation ability of the internalizing cell peptide - trans-activating transcriptor (TAT) to enhance the nanoparticle uptake by the targeted cells. Our hypothesis is that these multi-ligand nanoparticles would show an increased accumulation at the injury site since GPIb specially binds to both P-selectin expressed on damaged endothelial cells and vWF deposited on injured subendothelium while the cell penetrating peptide -- TAT would facilitate enhanced uptake of these nanoparticles by the damaged vascular cells. To test this hypothesis, fluorescent drug loaded poly (D, L-lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG) nanoparticles (PLGA-PEG NPs) were formulated using a standard double emulsion method. We further conjugated GPIb and TAT via carbodiimide and avidin-biotin chemistry to the PLGA-PEG nanoparticles. Characterization of these nanoparticles indicated the average size to be about 200nm. Endothelial cell uptake studies indicated an optimal nanoparticle incubation time of one hour and optimal dose of 400 mug/ml. Biocompatibility results showed these particles to be non-toxic to endothelial cells. Moreover, dexamethasone release profiles from the nanoparticles demonstrated their ability to provide a sustained drug release over four weeks. Static and dynamic uptake studies of control, GPIb-conjugated, and GPIb-TAT-conjugated PLGA-PEG nanoparticles on activated endothelial cells exhibited an increased adhesion and uptake of GPIb-TAT conjugated PLGA-PEG nanoparticles compared to control nanoparticles. A similar trend of significantly higher adhesion of GPIb-TAT conjugated PLGA-PEG nanoparticles to the injured vessel wall was also observed in preliminary ex-vivo studies using the rat carotid injury model. These results suggest that "our novel multi-ligand NPs" would provide a unique active targeting strategy. This system would rapidly target and deliver therapeutic agents to the injured vascular wall under flow conditions. It could also serve as an effective therapeutic delivery system to treat the complications associated with cardiovascular diseases.

Kona, Soujanya