García-Díaz, María; Foged, Camilla; Nielsen, Hanne Mørck
Polymeric nanoparticles are widely investigated as drug delivery systems for oral administration. However, the hydrophobic nature of many polymers hampers effective loading of the particles with hydrophilic macromolecules such as insulin. Thus, the aim of this work was to improve the loading of insulin into poly(lactic-co-glycolic) acid (PLGA) nanoparticles by pre-assembly with amphiphilic lipids. Insulin was complexed with soybean phosphatidylcholine or sodium caprate by self-assembly and subsequently loaded into PLGA nanoparticles by using the double emulsion-solvent evaporation technique. The nanoparticles were characterized in terms of size, zeta potential, insulin encapsulation efficiency and loading capacity. Upon pre-assembly with lipids, there was an increased distribution of insulin into the organic phase of the emulsion, eventually resulting in significantly enhanced encapsulation efficiencies (90% as compared to 24% in the absence of lipids). Importantly, the insulin loading capacity was increased up to 20% by using the lipid-insulin complexes. The results further showed that a main fraction of the lipid was incorporated into the nanoparticles and remained associated to the polymer during release studies in buffers, whereas insulin was released in a non-complexed form as a burst of approximately 80% of the loaded insulin. In conclusion, the protein load in PLGA nanoparticles can be significantly increased by employing self-assembled protein-lipid complexes.
Hamishehkar, Hamed; Emami, Jaber; Najafabadi, Abdolhossien Rouholamini; Gilani, Kambiz; Minaiyan, Mohsen; Hassanzadeh, Kambiz; Mahdavi, Hamid; Koohsoltani, Maryam; Nokhodchi, Ali
The pulmonary route is an alternative route of administration for the systemic delivery of peptide and proteins with short-half lives. A long-acting formulation of insulin was prepared by encapsulation of protein into respirable, biodegradable microcapsules prepared by an oil in oil emulsification/solvent evaporation method. Insulin-loaded PLGA microcapsules prepared as a dry powder inhaler formulation were administered via the pulmonary route to diabetic rats and serum insulin and glucose concentrations were monitored. Control treatments consisted of respirable spray-dried insulin (RSDI) powder administered by intratracheal insufflation, insulin-loaded PLGA microcapsules and NPH (long-acting) insulin administered by subcutaneous (SC) administration. Pharmacokinetic analysis demonstrated that insulin administered in PLGA microcapsules illustrated a sustained release profile which resulted in a longer mean residence time, 4 and 5 fold longer than those after pulmonary administration of RSDI and SC injection of NPH insulin, respectively. Accordingly, the hypoglycemic profile followed a stable and sustained pattern which remained constant between 10 and 48 h. Results of the in vitro experiments were in good agreement with those of in vivo studies. Bronchoalveolar lavage fluid analysis indicated that microcapsules administration did not increase the activities of lactate dehydrogenase and total protein. However, histological examination of the lung tissue indicated a minor but detectable effect on the normal physiology of the rat lung. These findings suggest that the encapsulation of peptides and proteins into PLGA microcapsules technique could be a promising controlled delivery system for pulmonary administration.
Fonte, Pedro; Soares, Sandra; Costa, Ana; Andrade, José Carlos; Seabra, Vítor; Reis, Salette; Sarmento, Bruno
PLGA nanoparticles are useful to protect and deliver proteins in a localized or targeted manner, with a long-term systemic delivery pattern intended to last for a period of time, depending on polymer bioerosion and biodegradability. However, the principal concern regarding these carriers is the hydrolytic instability of polymer in aqueous suspension. Freeze-drying is a commonly used method to stabilize nanoparticles, and cryoprotectants may be also used, to even increase its physical stability. The aim of the present work was to analyze the influence of cryoprotectants on nanoparticle stability and porosity after freeze-drying, which may influence protein release and stability. It was verified that freeze-drying significantly increased the number of pores on PLGA-NP surface, being more evident when cryoprotectants are added. The presence of pores is important in a lyophilizate to facilitate its reconstitution in water, although this may have consequences to protein release and stability. The release profile of insulin encapsulated into PLGA-NP showed an initial burst in the first 2 h and a sustained release up to 48 h. After nanoparticles freeze-drying the insulin release increased about 18% in the first 2 h due to the formation of pores, maintaining a sustained release during time. After freeze-drying with cryoprotectants, the amount of insulin released was higher for trehalose and lower for sucrose, glucose, fructose and sorbitol comparatively to freeze-dried PLGA-NP with no cryoprotectant added. Besides the porosity, the ability of cryoprotectants to be adsorbed on the nanoparticles surface may also play an important role on insulin release and stability. PMID:23507897
Sheng, Jianyong; Han, Limei; Qin, Jing; Ru, Ge; Li, Ruixiang; Wu, Lihong; Cui, Dongqi; Yang, Pei; He, Yuwei; Wang, Jianxin
Although several strategies have been applied for oral insulin delivery to improve insulin bioavailability, little success has been achieved. To overcome multiple barriers to oral insulin absorption simultaneously, insulin-loaded N-trimethyl chitosan chloride (TMC)-coated polylactide-co-glycoside (PLGA) nanoparticles (Ins TMC-PLGA NPs) were formulated in our study. The Ins TMC-PLGA NPs were prepared using the double-emulsion solvent evaporation method and were characterized to determine their size (247.6 ± 7.2 nm), ζ-potential (45.2 ± 4.6 mV), insulin-loading capacity (7.8 ± 0.5%) and encapsulation efficiency (47.0 ± 2.9%). The stability and insulin release of the nanoparticles in enzyme-containing simulated gastrointestinal fluids suggested that the TMC-PLGA NPs could partially protect insulin from enzymatic degradation. Compared with unmodified PLGA NPs, the positively charged TMC-PLGA NPs could improve the mucus penetration of insulin in mucus-secreting HT29-MTX cells, the cellular uptake of insulin via clathrin- or adsorption-mediated endocytosis in Caco-2 cells and the permeation of insulin across a Caco-2 cell monolayer through tight junction opening. After oral administration in mice, the TMC-PLGA NPs moved more slowly through the gastrointestinal tract compared with unmodified PLGA NPs, indicating the mucoadhesive property of the nanoparticles after TMC coating. Additionally, in pharmacological studies in diabetic rats, orally administered Ins TMC-PLGA NPs produced a stronger hypoglycemic effect, with 2-fold higher relative pharmacological availability compared with unmodified NPs. In conclusion, oral insulin absorption is improved by TMC-PLGA NPs with the multiple absorption barriers overcome simultaneously. TMC-PLGA NPs may be a promising drug delivery system for oral administration of macromolecular therapeutics.
Jain, Sanyog; Rathi, Vishal V; Jain, Amit K; Das, Manasmita; Godugu, Chandraiah
The present study reports a novel approach for enhancing the oral absorption and hypoglycemic activity of insulin via encapsulation in folate-(FA) coupled polyethylene glycol (PEG)ylated polylactide-co-glycolide (PLGA) nanoparticles (NPs; FA-PEG-PLGA NPs). Insulin-loaded FA-PEG-PLGA NPs (size ∼260 nm; insulin loading ∼6.5% [w/w]; encapsulation efficiency: 87.0 ± 1.92%) were prepared by double-emulsion solvent evaporation method. The bioavailability and hypoglycemic activity of orally administered FA-insulin NPs were studied in diabetic rats. FA-PEG-PLGA NPs (50 U/kg) exhibited a twofold increase in the oral bioavailability (double hypoglycemia) without any hypoglycemic shock as compared to subcutaneously administered standard insulin solution. Insulin NPs maintained a continual blood glucose level for 24 h, which, however, was transient (<8 h) in the case of subcutaneous insulin and associated with severe hypoglycemic shock. Overall, we have developed a patient-compliant, oral nanoformulation of insulin, once-daily administration of which would be sufficient to control diabetes for at least 24 h.
Wu, Zhi Min; Ling, Li; Zhou, Li Ying; Guo, Xin Dong; Jiang, Wei; Qian, Yu; Luo, Kathy Qian; Zhang, Li Juan
The aim of the present study was to develop the PLGA/HP55 nanoparticles with improved hypoglycemic effect for oral insulin delivery. The insulin-loaded PLGA/HP55 nanoparticles were produced by a modified multiple emulsion solvent evaporation method. The physicochemical characteristics, in vitro release of insulin, and in vivo efficacy in diabetic rats of the nanoparticles were evaluated. The insulin encapsulation efficiency was up to 94%, and insulin was released in a pH-dependent manner under simulated gastrointestinal conditions. When administered orally (50 IU/kg) to diabetic rats, the nanoparticles can decrease rapidly the blood glucose level with a maximal effect between 1 and 8 h. The relative bioavailability compared with subcutaneous injection (5 IU/kg) in diabetic rats was 11.3% ± 1.05%. This effect may be explained by the fast release of insulin in the upper intestine, where it is better absorbed by the high gradient concentration of insulin than other regions. These results show that the PLGA/HP55 nanoparticles developed in the study might be employed as a potential method for oral insulin delivery.
Malathi, Sampath; Nandhakumar, Perumal; Pandiyan, Velayudham; Webster, Thomas J; Balasubramanian, Sengottuvelan
Background Insulin is the drug therapy for patients with insulin-dependent diabetes mellitus. A number of attempts have been made in the past to overcome the problems associated with the oral delivery of insulin, but with little success. Orally administered insulin has encountered with many difficulties such as rapid degradation and poor intestinal absorption. The potential use of D-α-tocopherol poly(ethylene glycol) 1000 succinate (TPGS)-emulsified poly(ethylene glycol) (PEG)-capped poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) was investigated for sustained delivery of insulin (IS). Objective To investigate the efficacy of TPGS-emulsified PEG-capped PLGA NPs (TPPLG NPs) as a potential drug carrier for the oral delivery of insulin. Methods A series of biodegradable low-molecular-weight PLGA (80/20 [PLG4] and 70/30 [PLG6]) copolymers were synthesized by melt polycondensation. The commercial insulin-loaded TPGS-emulsified PEG-capped PLGA NPs (ISTPPLG NPs) were synthesized by water–oil–water emulsion solvent evaporation method. The physical and chemical properties of PLGA copolymers, particle size, zeta potential, and morphology of the NPs were examined. The in vivo studies of ISTPPLG NPs were carried out in diabetic rats by oral administration. Results The maximum encapsulation efficiency of ISTPPLG6 NPs was 78.6%±1.2%, and the mean diameter of the NPs was 180±20 nm. The serum glucose level was significantly (twofold) decreased on treatment with ISTPPLG NPs, and there was a threefold decrease with insulin-loaded PLGA (70/30) NPs when compared to that of free insulin-treated diabetic rats. The results show that the oral administration of ISTPPLG6 NPs is an effective method of reducing serum glucose level for a period of 24 hours. Histopathological studies reveal that ISTPPLG NPs could restore the damage caused by streptozotocin in the liver, kidneys, and pancreas, indicating its biocompatibility and regenerative effects. Conclusion ISTPPLG6 NPs can
Rafiei, Pedram; Haddadi, Azita
Docetaxel is a highly potent anticancer agent being used in a wide spectrum of cancer types. There are important matters of concern regarding the drug’s pharmacokinetics related to the conventional formulation. Poly(lactide-co-glycolide) (PLGA) is a biocompatible/biodegradable polymer with variable physicochemical characteristics, and its application in human has been approved by the United States Food and Drug Administration. PLGA gives polymeric nanoparticles with unique drug delivery characteristics. The application of PLGA nanoparticles (NPs) as intravenous (IV) sustained-release delivery vehicles for docetaxel can favorably modify pharmacokinetics, biofate, and pharmacotherapy of the drug in cancer patients. Surface modification of PLGA NPs with poly(ethylene glycol) (PEG) can further enhance NPs’ long-circulating properties. Herein, an optimized fabrication approach has been used for the preparation of PLGA and PLGA–PEG NPs loaded with docetaxel for IV application. Both types of NP formulations demonstrated in vitro characteristics that were considered suitable for IV administration (with long-circulating sustained-release purposes). NP formulations were IV administered to an animal model, and docetaxel’s pharmacokinetic and biodistribution profiles were determined and compared between study groups. PLGA and PEGylated PLGA NPs were able to modify the pharmacokinetics and biodistribution of docetaxel. Accordingly, the mode of changes made to pharmacokinetics and biodistribution of docetaxel is attributed to the size and surface properties of NPs. NPs contributed to increased blood residence time of docetaxel fulfilling their role as long-circulating sustained-release drug delivery systems. Surface modification of NPs contributed to more pronounced docetaxel blood concentration, which confirms the role of PEG in conferring long-circulation properties to NPs. PMID:28184163
Dhall, Sandeep; Silva, João P; Liu, Yan; Hrynyk, Michael; Garcia, Monika; Chan, Alex; Lyubovitsky, Julia; Neufeld, Ronald J; Martins-Green, Manuela
Burn wound healing involves a complex set of overlapping processes in an environment conducive to ischaemia, inflammation and infection costing $7.5 billion/year in the U.S.A. alone, in addition to the morbidity and mortality that occur when the burns are extensive. We previously showed that insulin, when topically applied to skin excision wounds, accelerates re-epithelialization and stimulates angiogenesis. More recently, we developed an alginate sponge dressing (ASD) containing insulin encapsulated in PLGA [poly(D,L-lactic-co-glycolic acid)] microparticles that provides a sustained release of bioactive insulin for >20 days in a moist and protective environment. We hypothesized that insulin-containing ASD accelerates burn healing and stimulates a more regenerative, less scarring healing. Using heat-induced burn injury in rats, we show that burns treated with dressings containing 0.04 mg insulin/cm(2) every 3 days for 9 days have faster closure, a higher rate of disintegration of dead tissue and decreased oxidative stress. In addition, in insulin-treated wounds, the pattern of neutrophil inflammatory response suggests faster clearing of the burned dead tissue. We also observe faster resolution of the pro-inflammatory macrophages. We also found that insulin stimulates collagen deposition and maturation with the fibres organized more like a basket weave (normal skin) than aligned and cross-linked (scar tissue). In summary, application of ASD-containing insulin-loaded PLGA particles on burns every 3 days stimulates faster and more regenerative healing. These results suggest insulin as a potential therapeutic agent in burn healing and, because of its long history of safe use in humans, insulin could become one of the treatments of choice when repair and regeneration are critical for proper tissue function.
Khalil, Najeh Maissar; do Nascimento, Thuane Castro Frabel; Casa, Diani Meza; Dalmolin, Luciana Facco; de Mattos, Ana Cristina; Hoss, Ivonete; Romano, Marco Aurélio; Mainardes, Rubiana Mara
The aim of this study was to assess the potential of nanoparticles to improve the pharmacokinetics of curcumin, with a primary goal of enhancing its bioavailability. Polylactic-co-glycolic acid (PLGA) and PLGA-polyethylene glycol (PEG) (PLGA-PEG) blend nanoparticles containing curcumin were obtained by a single-emulsion solvent-evaporation technique, resulting in particles size smaller than 200 nm. The encapsulation efficiency was over 70% for both formulations. The in vitro release study showed that curcumin was released more slowly from the PLGA nanoparticles than from the PLGA-PEG nanoparticles. A LC-MS/MS method was developed and validated to quantify curcumin in rat plasma. The nanoparticles were orally administered at a single dose in rats, and the pharmacokinetic parameters were evaluated and compared with the curcumin aqueous suspension. It was observed that both nanoparticles formulations were able to sustain the curcumin delivery over time, but greater efficiency was obtained with the PLGA-PEG nanoparticles, which showed better results in all of the pharmacokinetic parameters analyzed. The PLGA and PLGA-PEG nanoparticles increased the curcumin mean half-life in approximately 4 and 6h, respectively, and the C(max) of curcumin increased 2.9- and 7.4-fold, respectively. The distribution and metabolism of curcumin decreased when it was carried by nanoparticles, particularly PLGA-PEG nanoparticles. The bioavailability of curcumin-loaded PLGA-PEG nanoparticles was 3.5-fold greater than the curcumin from PLGA nanoparticles. Compared to the curcumin aqueous suspension, the PLGA and PLGA-PEG nanoparticles increased the curcumin bioavailability by 15.6- and 55.4-fold, respectively. These results suggest that PLGA and, in particular, PLGA-PEG blend nanoparticles are potential carriers for the oral delivery of curcumin. Copyright © 2012 Elsevier B.V. All rights reserved.
Lin, Ts-Ting; Gao, Dong-Yu; Liu, Ya-Chi; Sung, Yun-Chieh; Wan, Dehui; Liu, Jia-Yu; Chiang, Tsaiyu; Wang, Liying; Chen, Yunching
Sorafenib is a tyrosine kinase inhibitor that has recently been shown to be a potential antifibrotic agent. However, a narrow therapeutic window limits the clinical use and therapeutic efficacy of sorafenib. Herein, we have developed and optimized nanoparticle (NP) formulations prepared from a mixture of poly(ethylene glycol)-b-poly(lactic-co-glycolic acid) (PEG-PLGA) copolymers with poly(lactic-co-glycolic acid) (PLGA) for the systemic delivery of sorafenib into the fibrotic livers of CCl4-induced fibrosis mouse models. We characterized and compared the pharmaceutical and biological properties of two different PLGA nanoparticles (NPs)--PEG-PLGA NPs (PEG-PLGA/PLGA=10/0) and PEG-PLGA/PLGA NPs (PEG-PLGA/PLGA=5/5). Increasing the PLGA content in the PEG-PLGA/PLGA mixture led to increases in the particle size and drug encapsulation efficacy and a decrease in the drug release rate. Both PEG-PLGA and PEG-PLGA/PLGA NPs significantly prolonged the blood circulation of the cargo and increased the uptake by the fibrotic livers. The systemic administration of PEG-PLGA or PEG-PLGA/PLGA NPs containing sorafenib twice per week for a period of 4 weeks efficiently ameliorated liver fibrosis, as indicated by decreased α-smooth muscle actin (α-SMA) content and collagen production in the livers of CCl4-treated mice. Furthermore, sorafenib-loaded PLGA NPs significantly shrank the abnormal blood vessels and decreased microvascular density (MVD), leading to vessel normalization in the fibrotic livers. In conclusion, our results reflect the clinical potential of sorafenib-loaded PLGA NPs for the prevention and treatment of liver fibrosis. Copyright © 2015 Elsevier B.V. All rights reserved.
Kim, Byung Soo; Oh, Jae Min; Hyun, Hoon; Kim, Kyung Sook; Lee, Sang Hyo; Kim, Yu Han; Park, Kinam; Lee, Hai Bang; Kim, Moon Suk
Microencapsulation of insulin has been difficult, due to the high sensitivity of insulin to the harsh conditions that can occur during the microencapsulation process. We have developed a method of preparing insulin-loaded microcapsules by using a monoaxial ultrasonic atomizer to form microdroplets of insulin in aqueous solution surrounded by poly(lactic-co-glycolic acid) (PLGA) solution. Administration of these insulin-loaded microcapsules to type 1 diabetic rats maintained plasma insulin concentrations for 30 days, due to the sustained insulin release properties of the microcapsules. In contrast, plasma insulin concentrations after subcutaneous injection of insulin solution reached near zero levels within 2 days. Insulin solution showed only an immediate pharmacological effect, with no reduction of glycemia after 3 days, whereas insulin-loaded microcapsules maintained blood glucose levels at 100-200 mg/dL for 55 days. Molecular imaging using fluorescein isothiocyanate (FITC)-insulin-loaded microcapsules showed in vivo sustained release of the FITC-insulin in microcapsules. Using insulin-loaded microcapsules, we observed inflammation only immediately after injection, indicating that the rats adapted to long-term insulin release. In conclusion, insulin-loaded microcapsules may reduce nonrepetitive insulin administration and show sustained pharmacological performance.
Park, Min-Ho; Jun, Hye-Suk; Jeon, Jong-Woon; Park, Jin-Kyu; Lee, Bong-Joo; Suh, Guk-Hyun; Park, Jeong-Sook; Cho, Cheong-Weon
Bee venom-loaded poly(lactic-co-glycolic acid) (PLGA) particles were prepared by double emulsion-solvent evaporation, and characterized for a sustained-release system. Factors such as the type of organic solvent, the amount of bee venom and PLGA, the type of PLGA, the type of polyvinyl alcohol, and the emulsification method were considered. Physicochemical properties, including the encapsulation efficiency, drug loading, particle size, zeta-potential and surface morphology were examined by Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), and X-ray diffraction (XRD). The size of the bee venom-loaded PLGA particles was 500 nm (measured using sonication). Zeta-potentials of the bee venom-loaded PLGA particles were negative owing to the PLGA. FT-IR results demonstrated that the bee venom was completely encapsulated in the PLGA particles, indicated by the disappearance of the amine and amide peaks. In addition, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicated that the bee venom in the bee venom-loaded PLGA particles was intact. In vitro release of the bee venom from the bee venom-loaded PLGA particles showed a sustained-release profile over 1 month. Bee venom-loaded PLGA particles can help improve patients' quality of life by reducing the number of injections required.
Guimarães, Pedro Pires Goulart; Oliveira, Sheila Rodrigues; de Castro Rodrigues, Gabrielle; Gontijo, Savio Morato Lacerda; Lula, Ivana Silva; Cortés, Maria Esperanza; Denadai, Ângelo Márcio Leite; Sinisterra, Rubén Dario
The aim of this work was to synthesize sulfadiazine-poly(lactide-co-glycolide) (SUL-PLGA) nanoparticles (NPs) for the efficient delivery of 5-fluorouracil to cancer cells. The SUL-PLGA conjugation was assessed using FTIR, 1H-NMR, 13C-NMR, elemental analysis and TG and DTA analysis. The SUL-PLGA NPs were characterized using transmission and scanning electron microscopy and dynamic light scattering. Additionally, the zeta potential, drug content, and in vitro 5-FU release were evaluated. We found that for the SUL-PLGA NPs, Dh = 114.0 nm, ZP = -32.1 mV and the encapsulation efficiency was 49%. The 5-FU was released for up to 7 days from the NPs. Cytotoxicity evaluations of 5-FU-loaded NPs (5-FU-SUL-PLGA and 5-FU-PLGA) on two cancer cell lines (Caco-2, A431) and two normal cell lines (fibroblast, osteoblast) were compared. Higher cytotoxicity of 5-FU-SUL-PLGA NPs were found to both cancer cell lines when compared to normal cell lines, demonstrating that the presence of SUL could significantly enhance the cytotoxicity of the 5-FU-SUL-PLGA NPs when compared with 5-FU-PLGA NPs. Thus, the development of 5-FU-SUL-PLGA NPs to cancer cells is a promising strategy for the 5-FU antitumor formulation in the future.
Shi, Lei; Wang, Xiuli; Zhao, Feng; Luan, Hansen; Tu, Qingfeng; Huang, Zheng; Wang, Hao; Wang, Hongwei
Background 5-Aminolevulinic acid (ALA) is a prodrug for topical photodynamic therapy. The effectiveness of topical ALA can be limited by its bioavailability. The aim of this study was to develop a novel ALA delivery approach using poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). Methods A modified double emulsion solvent evaporation method was used to prepare ALA loaded PLGA NPs (ALA PLGA NPs). The characteristics, uptake, protoporphyrin IX fluorescence kinetics, and cytotoxicity of ALA PLGA NPs toward a human skin squamous cell carcinoma cell line were examined. Results The mean particle size of spherical ALA PLGA NPs was 65.6 nm ± 26 nm with a polydispersity index of 0.62. The encapsulation efficiency was 65.8% ± 7.2% and ALA loading capacity was 0.62% ± 0.27%. When ALA was dispersed in PLGA NPs, it turned into an amorphous phase. ALA PLGA NPs could be taken up by squamous cell carcinoma cells and localized in the cytoplasm. The protoporphyrin IX fluorescence kinetics and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay showed that ALA PLGA NPs were more effective than free ALA of the same concentration. Conclusion PLGA NPs provide a promising ALA delivery strategy for topical ALA-photodynamic therapy of skin squamous cell carcinoma. PMID:23926429
Shi, Lei; Wang, Xiuli; Zhao, Feng; Luan, Hansen; Tu, Qingfeng; Huang, Zheng; Wang, Hao; Wang, Hongwei
5-Aminolevulinic acid (ALA) is a prodrug for topical photodynamic therapy. The effectiveness of topical ALA can be limited by its bioavailability. The aim of this study was to develop a novel ALA delivery approach using poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs). A modified double emulsion solvent evaporation method was used to prepare ALA loaded PLGA NPs (ALA PLGA NPs). The characteristics, uptake, protoporphyrin IX fluorescence kinetics, and cytotoxicity of ALA PLGA NPs toward a human skin squamous cell carcinoma cell line were examined. The mean particle size of spherical ALA PLGA NPs was 65.6 nm±26 nm with a polydispersity index of 0.62. The encapsulation efficiency was 65.8%±7.2% and ALA loading capacity was 0.62%±0.27%. When ALA was dispersed in PLGA NPs, it turned into an amorphous phase. ALA PLGA NPs could be taken up by squamous cell carcinoma cells and localized in the cytoplasm. The protoporphyrin IX fluorescence kinetics and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay showed that ALA PLGA NPs were more effective than free ALA of the same concentration. PLGA NPs provide a promising ALA delivery strategy for topical ALA-photodynamic therapy of skin squamous cell carcinoma.
Zidan, Ahmed S.; Rahman, Ziyaur; Habib, Muhammad J.; Khan, Mansoor A.
The objective of this study was to evaluate near infrared (NIR) spectroscopy and imaging as approaches to assess drug contents in poly(dl-lactide-co-glycolide) (PLGA) based nanoparticles of a model protein, cyclosporine A (CyA). A 6-factors 12-runs designed set of experiments with Plackett–Burman (PB) screening was applied in order to examine the effects of drug loading (X1), polymer loading (X2), emulsifier concentration (X3), stirring rate (X4), type of organic solvent (X5), and ratio of organic to aqueous phases' volumes (X6), on drug entrapment efficiency (EFF). After omitting the factors with nonsignificant influences on EFF, a reduced mathematical relationship, EFF = 48.34 + 7.3X1 − 29.95X3, was obtained to explain the effect of the significant factors on EFF. Using two different sets for calibration and validation, the developed NIR calibration model was able to assess CyA contents within the 12 PB formulations. NIR spectral imaging was capable of clearly distinguishing the 12 formulations, both qualitatively and quantitatively. A good correlation with a coefficient of 0.9727 was obtained for constructing a quantile-quantile plot for the actual drug loading percentage and the % standard deviation obtained for the drug loading prediction using the hyperspectral images. PMID:19774658
Hosseininasab, Sara; Pashaei-Asl, Roghiyeh; Khandaghi, Amir Ahmad; Nasrabadi, Hamid Tayefi; Nejati-Koshki, Kazem; Akbarzadeh, Abolfazl; Joo, Sang Woo; Hanifehpour, Younes; Davaran, Soodabeh
Therapeutic proteins and peptides are corresponding to a major area of research in biotechnology companies and current pharmaceutical. Because of their natural instability, the enormous majority of these drugs require parentéral administration. Oral insulin delivery would be a highly attractive alternative process of administration, though it continues to be a mysterious target due to the enzymatic digestion of insulin and low levels of absorption from the gastrointestinal region. Hydrogel polymers can be considered as potential carriers for oral insulin delivery. In particular, a pH responsive hydrogel composed of PLGA-PEG has shown the ability to protect insulin from enzymes in the gastric environment and release in small intestines. However, this material has not shown similar potential for oral protein delivery of further model drugs. To date, the unique interaction between PLGA-PEG and insulin, as a potential drug for oral delivery, is not completely understood. The focus of this research is synthetization and characterization of hydrogels PLGA-PEG insulin nanoparticles and also pH sensitivity of insulin nanoparticles was investigated.
Shabir, Anjumn; Alhusban, Farhan; Perrie, Yvonne; Mohammed, Afzal R.
PLGA is a biodegradable polymer utilised widely in pharmaceutical research for the encapsulation of a wide range of drugs as nano particulate systems. This study investigates the impact of rotary ball milling on the physical properties of PLGA and its influence on nanoparticle formation prepared using the solvent displacement technique. By applying mechanical stress to the polymer and altering its physical appearance and molecular weight, the loading of lansoprazole within the nanoparticles was increased to 96%, with a reduction in particle size. The results indicate that rotary ball milling significantly reduces particle size, increases lansoprazole loading and improves the release profile for lansoprazole loaded PLGA nanoparticles PMID:24826005
Yan, Qi; Xiao, Li-Qun; Tan, Lei; Sun, Wei; Wu, Tao; Chen, Liang-Wen; Mei, Yan; Shi, Bin
Reports on the local delivery of drug loaded injectable hydrogels for bone regeneration are currently limited. This study assessed the effect of controlled simvastatin (SIM) release from a thermo-sensitive hydrogel in vitro and in vivo. We successfully manufactured and evaluated thermo-sensitive poly(d,l-lactide-co-glycolide)-poly(ethylene glycol)-poly(d,l-lactide-co-glycolide) triblock copolymers (PLGA-PEG-PLGA) loaded with SIM. The osteogenic effect of this hydrogel was tested in vitro and in vivo. MC-3T3 E1 cells proliferation and osteoblastic differentiation was analyzed after cultivation with the hydrogel extracts. Cells co-cultured with SIM/PLGA-PEG-PLGA extracts showed an increase in mineralization and osteogenic gene expression compared to the other two groups. Additionally, the characteristics of this composite in vivo were demonstrated using a rat bone defect model. The bone defects injected with SIM/PLGA-PEG-PLGA hydrogel showed increased new bone formation compared to samples treated with PLGA-PEG-PLGA and control samples. The results of this study suggest that SIM/PLGA-PEG-PLGA might provide potential therapeutic value for bone healing.
Byeon, Hyeong Jun; Kim, Insoo; Choi, Ji Su; Lee, Eun Seong; Shin, Beom Soo; Youn, Yu Seok
The aim of the current study was to investigate the antitumor potential of poly (D,L-lactic-co-glycolic acid) microspheres (PLGA MSs) containing polyethylene glycol (PEG)-conjugated (PEGylated) tumor necrosis factor-related apoptosis-inducing ligand (PEG-TRAIL). PEG-TRAIL PLGA MSs were prepared by using a water-in-oil-in-water double-emulsion method, and the apoptotic activities of supernatants released from the PLGA MSs at days 1, 3, and 7 were examined. The antitumor effect caused by PEG-TRAIL PLGA MSs was evaluated in pancreatic Mia Paca-2 cell-xenografted mice. PEG-TRAIL PLGA MS was found to be spherical and 14.4±1.06 μm in size, and its encapsulation efficiency was significantly greater than that of TRAIL MS (85.7%±4.1% vs 43.3%±10.9%, respectively). The PLGA MS gradually released PEG-TRAIL for 14 days, and the released PEG-TRAIL was shown to have clear apoptotic activity in Mia Paca-2 cells, whereas TRAIL released after 1 day had a negligible activity. Finally, PEG-TRAIL PLGA MS displayed remarkably greater antitumor efficacy than blank or TRAIL PLGA MS in Mia Paca-2 cell-xenografted mice in terms of tumor volume and weight, apparently due to increased stability and well-retained apoptotic activity of PEG-TRAIL in PLGA MS. We believe that this PLGA MS system, combined with PEG-TRAIL, should be considered a promising candidate for treating pancreatic cancer.
Byeon, Hyeong Jun; Kim, Insoo; Choi, Ji Su; Lee, Eun Seong; Shin, Beom Soo; Youn, Yu Seok
The aim of the current study was to investigate the antitumor potential of poly (D,L-lactic-co-glycolic acid) microspheres (PLGA MSs) containing polyethylene glycol (PEG)-conjugated (PEGylated) tumor necrosis factor–related apoptosis-inducing ligand (PEG-TRAIL). PEG-TRAIL PLGA MSs were prepared by using a water-in-oil-in-water double-emulsion method, and the apoptotic activities of supernatants released from the PLGA MSs at days 1, 3, and 7 were examined. The antitumor effect caused by PEG-TRAIL PLGA MSs was evaluated in pancreatic Mia Paca-2 cell-xenografted mice. PEG-TRAIL PLGA MS was found to be spherical and 14.4±1.06 μm in size, and its encapsulation efficiency was significantly greater than that of TRAIL MS (85.7%±4.1% vs 43.3%±10.9%, respectively). The PLGA MS gradually released PEG-TRAIL for 14 days, and the released PEG-TRAIL was shown to have clear apoptotic activity in Mia Paca-2 cells, whereas TRAIL released after 1 day had a negligible activity. Finally, PEG-TRAIL PLGA MS displayed remarkably greater antitumor efficacy than blank or TRAIL PLGA MS in Mia Paca-2 cell-xenografted mice in terms of tumor volume and weight, apparently due to increased stability and well-retained apoptotic activity of PEG-TRAIL in PLGA MS. We believe that this PLGA MS system, combined with PEG-TRAIL, should be considered a promising candidate for treating pancreatic cancer. PMID:25632232
Zou, Lidi; Chen, Fengqian; Bao, Jiaolin; Wang, Shengpeng; Wang, Lu; Chen, Meiwan; He, Chengwei; Wang, Yitao
Evodiamine (EVO) is a plant-derived indolequinazoline alkaloid with potential anticancer activity. However, low bioavailability caused by its poor water solubility limits it anticancer efficacy in clinic. To enhance the solubility and improve the bioavailability of EVO, a delivery system based on poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with EVO (EVO-PLGA NPs) for treating breast cancer was prepared in this study. The physicochemical characterization and in vitro antitumor evaluation of EVO-PLGA NPs were determined. EVO-PLGA NPs could persistently control the release of EVO for 180 h. 3-[4,5-Dimethyl-2-thiazolyl]-2,5-diphenyl tetrazolium bromide (MTT) assessment and colony formation assay showed that EVO-PLGA NPs could enhance the toxicity and the proliferation inhibition effect of EVO on MCF-7 breast cancer cells. EVO-PLGA NPs did not strengthen G2/M arrest effect of EVO-treated cells after 24h incubation. Meanwhile, EVO-PLGA NPs could increase the expression of cyclin B1 and decrease the expression of β-actin. Taken together, these results suggested that -PLGA NPs is promising for improving anticancer efficacy of EVO in breast cancer therapy.
Gao, Nansha; Chen, Zhihong; Xiao, Xiaojun; Ruan, Changshun; Mei, Lin; Liu, Zhigang; Zeng, Xiaowei
In order to enhance the therapeutic effect of chemotherapy on liver cancer, a biodegradable formulation of protamine-modified paclitaxel-loaded poly(lactide- co-glycolide)- b-poly(ethylene glycol)- b-poly(lactide- co-glycolide) (PLGA- b-PEG- b-PLGA) nanoparticles (PTX-loaded/protamine NPs) was prepared. Tri-block copolymer PLGA- b-PEG- b-PLGA was synthesized by ring-opening polymerization and characterized by 1H NMR spectroscopy and gel permeation chromatography. PTX-loaded and PTX-loaded/protamine NPs were characterized in terms of size, size distribution, zeta potential, surface morphology, drug encapsulation efficiency, and drug release. Confocal laser scanning microscopy showed that coumarin 6-loaded/protamine NPs were internalized by hepatocellular carcinoma cell line HepG2. The cellular uptake efficiency of NPs was obviously elevated after protamine modification. With commercial formulation Taxol® as the reference, HepG2 cells were also used to study the cytotoxicity of the NPs. PTX-loaded/protamine NPs exhibited significantly higher cytotoxicity than PTX-loaded NPs and Taxol® did. All the results suggested that surface modification of PTX-loaded PLGA- b-PEG- b-PLGA NPs with protamine boosted the therapeutic efficacy on liver cancer.
Liu, Hongyan; Xu, Hong; Zhang, Chenghong; Gao, Meng; Gao, Xiaoguang; Ma, Chuchu; Lv, Li; Gao, Dongyan; Deng, Sa; Wang, Changyuan; Tian, Yan
Heparin sodium (HS)-loaded polylactic-co-glycolic acid-D-α-tocopheryl polyethylene glycol 1000 succinate (PLGA-TPGS) nanoparticles (HPTNs) were prepared as a sustained and targeting delivery carrier and combined with emodin (EMO)-loaded PLGA-TPGS nanoparticles (EPTNs), which were investigated previously to form a combination therapy system for the treatment of liver cancer. To assess cellular uptake and evaluate the liver-targeting capacity by analyzing the drug concentrations and frozen slices, HS/eosin-loaded PLGA-TPGS nanoparticles, HS/fluorescein- loaded PLGA-TPGS nanoparticles and EMO/C6-loaded PLGA-TPGS nanoparticles, which contained eosin, fluorescein and C6 as fluorescent probes, respectively, were also prepared. All of these nanoparticles were characterized in terms of their size, size distribution, surface charge, drug loading, encapsulation efficiency, in vitro release profile and cellular uptake. The apoptosis of HepG2 cells induced by EPTNs in combination with HPTNs was determined by Annexin V-FITC staining and PI labelling. Transmission electron microscopy indicated that these nanoparticles were stably dispersed spheres with sizes ranging from 100 to 200 nm. The results demonstrated that fluorescent nanoparticles were internalized into HepG2 and HCa-F cells efficiently and had improved liver-targeting properties. The combination of EPTNs and HPTNs effectively inhibited cell growth in vitro and had a remarkable synergistic anticancer effect in vivo. EPTNs combined with HPTNs induced HepG2 cell apoptosis with synergistic effects. The liver H&E slice images of a hepatocarcinogenic mouse model indicated that EPTNs in combination with HPTNs significantly suppressed tumour growth in vivo. The research suggests that the combination therapy system of EPTNs and HPTNs could be a new direction for liver cancer therapy.
Haider, Adnan; Gupta, Kailash Chandra; Kang, Inn-Kyu
The development of tissue engineering in the field of orthopedic surgery is booming. Two fields of research in particular have emerged: approaches for tailoring the surface properties of implantable materials with osteoinductive factors as well as evaluation of the response of osteogenic cells to these fabricated implanted materials (hybrid material). In the present study, we chemically grafted insulin onto the surface of hydroxyapatite nanorods (nHA). The insulin-grafted nHAs (nHA-I) were dispersed into poly(lactide-co-glycolide) (PLGA) polymer solution, which was electrospun to prepare PLGA/nHA-I composite nanofiber scaffolds. The morphology of the electrospun nanofiber scaffolds was assessed by field emission scanning electron microscopy (FESEM). After extensive characterization of the PLGA/nHA-I and PLGA/nHA composite nanofiber scaffolds by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectrometry (EDS), and transmission electron microscopy (TEM), the PLGA/nHA-I and PLGA/nHA (used as control) composite nanofiber scaffolds were subjected to cell studies. The results obtained from cell adhesion, alizarin red staining, and Von Kossa assay suggested that the PLGA/nHA-I composite nanofiber scaffold has enhanced osteoblastic cell growth, as more cells were proliferated and differentiated. The fact that insulin enhanced osteoblastic cell proliferation will open new possibilities for the development of artificial scaffolds for bone tissue regeneration.
The development of tissue engineering in the field of orthopedic surgery is booming. Two fields of research in particular have emerged: approaches for tailoring the surface properties of implantable materials with osteoinductive factors as well as evaluation of the response of osteogenic cells to these fabricated implanted materials (hybrid material). In the present study, we chemically grafted insulin onto the surface of hydroxyapatite nanorods (nHA). The insulin-grafted nHAs (nHA-I) were dispersed into poly(lactide-co-glycolide) (PLGA) polymer solution, which was electrospun to prepare PLGA/nHA-I composite nanofiber scaffolds. The morphology of the electrospun nanofiber scaffolds was assessed by field emission scanning electron microscopy (FESEM). After extensive characterization of the PLGA/nHA-I and PLGA/nHA composite nanofiber scaffolds by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectrometry (EDS), and transmission electron microscopy (TEM), the PLGA/nHA-I and PLGA/nHA (used as control) composite nanofiber scaffolds were subjected to cell studies. The results obtained from cell adhesion, alizarin red staining, and Von Kossa assay suggested that the PLGA/nHA-I composite nanofiber scaffold has enhanced osteoblastic cell growth, as more cells were proliferated and differentiated. The fact that insulin enhanced osteoblastic cell proliferation will open new possibilities for the development of artificial scaffolds for bone tissue regeneration. PMID:25024679
Yeh, Hsi-Wei; Chen, Da-Ren
We investigated the effects of drug loading location, matrix material and shell thickness on the in vitro release of combinational drugs from core-shell PLGA (i.e., poly(lactic-co-glycolic acid)) particles. Budesonide and Theophylline were selected as highly hydrophobic and hydrophilic model drugs, respectively. The dual-capillary electrospray (ES) technique, operated at the cone-jet mode, was used to produce samples of drug-loaded core-shell composite particles with selected overall sizes, polymer materials, and shell thicknesses. Theophylline and Budesonide were loaded at different locations in a PLGA composite particle. This study illustrated how the aforementioned factors affect the release rates of Budesonide and Theophylline loaded in core-shell PLGA composites. We further identified that core-shell composite particles with both model drugs loaded in the core and with matrix PLGA polymers of low molecular weights and low LA/GA ratios are the best formulation for the sustained release of highly hydrophilic and hydrophobic active pharmaceutical ingredients from PLGA composite particles. The formulation strategy obtained in this study can be in principle generalized for biopharmaceutical applications in fixed-dose combination therapy. Copyright © 2017 Elsevier B.V. All rights reserved.
Shin, Yong Cheol; Shin, Dong-Myeong; Lee, Eun Ji; Lee, Jong Ho; Kim, Ji Eun; Song, Sung Hwa; Hwang, Dae-Youn; Lee, Jun Jae; Kim, Bongju; Lim, Dohyung; Hyon, Suong-Hyu; Lim, Young-Jun; Han, Dong-Wook
During the last few decades, considerable research on diabetic wound healing strategies has been performed, but complete diabetic wound healing remains an unsolved problem, which constitutes an enormous biomedical burden. Herein, hyaluronic acid (HA)/poly(lactic-co-glycolic acid, PLGA) core/shell fiber matrices loaded with epigallocatechin-3-O-gallate (EGCG) (HA/PLGA-E) are fabricated by coaxial electrospinning. HA/PLGA-E core/shell fiber matrices are composed of randomly-oriented sub-micrometer fibers and have a 3D porous network structure. EGCG is uniformly dispersed in the shell and sustainedly released from the matrices in a stepwise manner by controlled diffusion and PLGA degradation over four weeks. EGCG does not adversely affect the thermomechanical properties of HA/PLGA-E matrices. The number of human dermal fibroblasts attached on HA/PLGA-E matrices is appreciably higher than that on HA/PLGA counterparts, while their proliferation is steadily retained on HA/PLGA-E matrices. The wound healing activity of HA/PLGA-E matrices is evaluated in streptozotocin-induced diabetic rats. After two weeks of surgical treatment, the wound areas are significantly reduced by the coverage with HA/PLGA-E matrices resulting from enhanced re-epithelialization/neovascularization and increased collagen deposition, compared with no treatment or HA/PLGA. In conclusion, the HA/PLGA-E matrices can be potentially exploited to craft strategies for the acceleration of diabetic wound healing and skin regeneration.
Guo, Jun; Wu, Shu-Hong; Ren, Wei-Guo; Wang, Xin-Li; Yang, Ai-Qing
Prostate cancer is the most commonly diagnosed non-cutaneous malignancy in men in western and most developing countries. Bicalutamide (BLT) is an antineoplastic hormonal agent primarily used in the treatment of locally advanced and metastatic prostate cancers. In the present study, the aim was to develop a nanotechnology-based delivery system to target prostate cancer cells. This involved the development of a BLT-loaded poly(D,L-lactide-co-glycolide) PLGA (PLGA-BLT) nanoparticulate system in an attempt to improve the therapeutic efficacy of BLT in prostate cancer and to mitigate its toxicity. Nanosized particles with a uniform size distribution and spherical shape were developed. PLGA-BLT showed a pronounced cytotoxic effect on LNCaP and C4-2 cancer cells. The superior cell-killing effect of the nanoparticles may be attributable to their sustained drug-release characteristics and high cellular internalization. PLGA-BLT was also found to significantly inhibit colony formation in the two cell lines. Furthermore, the caspase-3 activity of PLGA-BLT treated cancer cells was enhanced, indicating the cell apoptosis-inducing potential of PLGA-BLT. Overall, these results suggest that nanotechnology-based formulations of BLT exhibit superior anticancer activity and have enormous potential in the treatment of prostate cancers.
GUO, JUN; WU, SHU-HONG; REN, WEI-GUO; WANG, XIN-LI; YANG, AI-QING
Prostate cancer is the most commonly diagnosed non-cutaneous malignancy in men in western and most developing countries. Bicalutamide (BLT) is an antineoplastic hormonal agent primarily used in the treatment of locally advanced and metastatic prostate cancers. In the present study, the aim was to develop a nanotechnology-based delivery system to target prostate cancer cells. This involved the development of a BLT-loaded poly(D,L-lactide-co-glycolide) PLGA (PLGA-BLT) nanoparticulate system in an attempt to improve the therapeutic efficacy of BLT in prostate cancer and to mitigate its toxicity. Nanosized particles with a uniform size distribution and spherical shape were developed. PLGA-BLT showed a pronounced cytotoxic effect on LNCaP and C4-2 cancer cells. The superior cell-killing effect of the nanoparticles may be attributable to their sustained drug-release characteristics and high cellular internalization. PLGA-BLT was also found to significantly inhibit colony formation in the two cell lines. Furthermore, the caspase-3 activity of PLGA-BLT treated cancer cells was enhanced, indicating the cell apoptosis-inducing potential of PLGA-BLT. Overall, these results suggest that nanotechnology-based formulations of BLT exhibit superior anticancer activity and have enormous potential in the treatment of prostate cancers. PMID:26668633
Rosa, A.R.; Steffens, D.; Santi, B.; Quintiliano, K.; Steffen, N.; Pilger, D.A.; Pranke, P.
The association of bioactive molecules, such as vascular endothelial growth factor (VEGF), with nanofibers facilitates their controlled release, which could contribute to cellular migration and differentiation in tissue regeneration. In this research, the influence of their incorporation on a polylactic-co-glycolic acid (PLGA) scaffold produced by electrospinning on cell adhesion and viability and cytotoxicity was carried out in three groups: 1) PLGA/BSA/VEGF; 2) PLGA/BSA, and 3) PLGA. Morphology, fiber diameter, contact angle, loading efficiency and controlled release of VEGF of the biomaterials, among others, were measured. The nanofibers showed smooth surfaces without beads and with interconnected pores. PLGA/BSA/VEGF showed the smallest water contact angle and VEGF released for up to 160 h. An improvement in cell adhesion was observed for the PLGA/BSA/VEGF scaffolds compared to the other groups and the scaffolds were non-toxic for the cells. Therefore, the scaffolds were shown to be a good strategy for sustained delivery of VEGF and may be a useful tool for tissue engineering. PMID:28793048
Rosa, A R; Steffens, D; Santi, B; Quintiliano, K; Steffen, N; Pilger, D A; Pranke, P
The association of bioactive molecules, such as vascular endothelial growth factor (VEGF), with nanofibers facilitates their controlled release, which could contribute to cellular migration and differentiation in tissue regeneration. In this research, the influence of their incorporation on a polylactic-co-glycolic acid (PLGA) scaffold produced by electrospinning on cell adhesion and viability and cytotoxicity was carried out in three groups: 1) PLGA/BSA/VEGF; 2) PLGA/BSA, and 3) PLGA. Morphology, fiber diameter, contact angle, loading efficiency and controlled release of VEGF of the biomaterials, among others, were measured. The nanofibers showed smooth surfaces without beads and with interconnected pores. PLGA/BSA/VEGF showed the smallest water contact angle and VEGF released for up to 160 h. An improvement in cell adhesion was observed for the PLGA/BSA/VEGF scaffolds compared to the other groups and the scaffolds were non-toxic for the cells. Therefore, the scaffolds were shown to be a good strategy for sustained delivery of VEGF and may be a useful tool for tissue engineering.
Park, Min-Ho; Kim, Ju-Heon; Jeon, Jong-Woon; Park, Jin-Kyu; Lee, Bong-Joo; Suh, Guk-Hyun; Cho, Cheong-Weon
It is known that allergic people was potentially vulnerable to bee venom (BV), which can induce an anaphylactic shock, eventually leading to death. Up until recently, this kind of allergy was treated only by venom immunotherapy (VIT) and its efficacy has been recognized worldwide. This treatment is practiced by subcutaneous injections that gradually increase the doses of the allergen. This is inconvenient for patients due to frequent injections. Poly (D,L-lactide-co-glycolide) (PLGA) has been broadly studied as a carrier for drug delivery systems (DDS) of proteins and peptides. PLGA particles usually induce a sustained release. In this study, the physicochemical properties of BV were examined prior to the preparation of BV-loaded PLGA nanoparticles NPs). The content of melittin, the main component of BV, was 53.3%. When protected from the light BV was stable at 4 °C in distilled water, during 8 weeks. BV-loaded PLGA particles were prepared using dichloromethane as the most suitable organic solvent and two min of ultrasonic emulsification time. This study has characterized the physicochemical properties of BV for the preparation BV-loaded PLGA NPs in order to design and optimize a suitable sustained release system in the future.
Tafaghodi, M; Eskandari, M; Kharazizadeh, M; Khamesipour, A; Jaafari, M R
Immune responses against the Leishmania antigens are not sufficient to protect against a leishmania challenge. Therefore these antigens need to be potentiated by various adjuvants and delivery systems. In this study, Poly (d,l-lactide-co-glycolide (PLGA) nanospheres as antigen delivery system and Quillaja saponins (QS) as immunoadjuvant have been used to enhance the immune response against autoclaved Leishmania major (ALM). PLGA nanospheres were prepared by a double-emulsion (W/O/W) technique. Particulate characteristics were studied by scanning electron microscopy and particle size analysis. Mean diameter for nanospheres loaded with ALM+QS was 294 ± 106 nm. BALB/c mice were immunized three times in 3-weeks intervals using ALM plus QS loaded nanospheres [(ALM+QS)PLGA], ALM encapsulated with PLGA nanospheres [(ALM)PLGA], (ALM)PLGA + QS, ALM + QS, ALM alone or PBS. The intensity of infection induced by L. major challenge was assessed by measuring size of footpad swelling. The strongest protection, showed by significantly (P < 0.05) smaller footpad, were observed in mice immunized with (ALM)PLGA. The (ALM+QS)PLGA group showed the least protection and highest swelling, while the (ALM)PLGA+QS, ALM+QS and ALM showed an intermediate protection with no significant difference. The mice immunized with ALM and ALM+QS showed the highest IgG2a/IgG1 ratio (P < 0.01), followed by (ALM)PLGA+QS. The highest IFN-γ and lowest IL-4 production was seen in (ALM)PLGA+QS, ALM+QS groups. The highest parasite burden was observed in (ALM)PLGA+QS and (ALM+QS)PLGA groups. It is concluded that PLGA nanospheres as a vaccine delivery system could increase the protective immune responses, but QS adjuvant has a reverse effect on protective immune responses and the least protective responses were seen in the presence of this adjuvant.
Zhang, Jinxie; Tao, Wei; Chen, Yuhan; Chang, Danfeng; Wang, Teng; Zhang, Xudong; Mei, Lin; Zeng, Xiaowei; Huang, Laiqiang
A doxorubicin-loaded mannitol-functionalized poly(lactide-co-glycolide)-b-D-α-tocopheryl polyethylene glycol 1000 succinate nanoparticles (DOX-loaded M-PLGA-b-TPGS NPs) were prepared by a modified nanoprecipitation method. The NPs were characterized by the particle size, surface morphology, particle stability, in vitro drug release and cellular uptake efficiency. The NPs were near-spherical with narrow size distribution. The size of M-PLGA-b-TPGS NPs was ~110.9 nm (much smaller than ~143.7 nm of PLGA NPs) and the zeta potential was -35.8 mV (higher than -42.6 mV of PLGA NPs). The NPs exhibited a good redispersion since the particle size and surface charge hardly changed during 3-month storage period. In the release medium (phosphate buffer solution vs. fetal bovine serum), the cumulative drug release of DOX-loaded M-PLGA-b-TPGS, PLGA-b-TPGS, and PLGA NPs were 76.41 versus 83.11 %, 58.94 versus 73.44 % and 45.14 versus 53.12 %, respectively. Compared with PLGA-b-TPGS NPs and PLGA NPs, the M-PLGA-b-TPGS NPs possessed the highest cellular uptake efficiency in A549 and H1975 cells (lung cancer cells). Ultimately, both in vitro and in vivo antitumor activities were evaluated. The results showed that M-PLGA-b-TPGS NPs could achieve a significantly higher level of cytotoxicity in cancer cells and a better antitumor efficiency on xenograft BALB/c nude mice tumor model than free DOX. In conclusion, the DOX-loaded M-PLGA-b-TPGS could be used as a potential DOX-loaded nanoformulation in lung cancer chemotherapy.
Gajendiran, M; Divakar, S; Raaman, N; Balasubramanian, S
Poly (lactic-co-glycolic acid) (PLGA (92:8)) and a series of PLGA-PEG-PLGA tri block copolymers were synthesized by direct melt polycondensation. The copolymers were characterized by FTIR, and 1HNMR spectroscopic techniques, viscosity, gel permeation chromatography (GPC) and powder x-ray diffraction (XRD). The rifampicin (RIF) loaded polymeric nanospheres (NPs) were prepared by ultrasonication-W/O emulsification technique. The NPs have been characterized by field emission scanning electron microscopy (FESEM), TEM, powder X-ray diffraction (XRD), UVvisible spectroscopy and DLS measurements. The drug loaded triblock copolymeric NPs have five folds higher drug content and drug loading efficiency than that of PLGA microspheres (MPs). The in vitro drug release study shows that the drug loaded NPs showed an initial burst release after that sustained release up to 72 h. All the triblock copolymeric NPs follow anomalous drug diffusion mechanism while the PLGA MPs follow non-Fickian super case-II mechanism up to 12 h. The overall in-vitro release follows second order polynomial kinetics up to 72 h. The antimicrobial activity of the RIF loaded polymer NPs was compared with that of pure RIF and tetracycline (TA). The RIF loaded triblock copolymeric NPs inhibited the bacterial growth more effectively than the pure RIF and TA.
Derman, Serap; Mustafaeva, Zeynep Akdeste; Abamor, Emrah Sefik; Bagirova, Melahat; Allahverdiyev, Adil
Canine parvovirus 2 (CPV-2) remains a significant worldwide canine pathogen and the most common cause of viral enteritis in dogs. The 1 L15 and 7 L15 peptides overlap each other with QPDGGQPAV residues (7-15 of VP2 capsid protein of CPV) is shown to produce high immune response. PLGA nanoparticles were demonstrated to have special properties such as; controlled antigen release, protection from degradation, elimination of booster-dose and enhancing the cellular uptake by antigen presenting cells. Nevertheless, there is no study available in literature, about developing vaccine based on PLGA nanoparticles with adjuvant properties against CPV. Thus, the aim of the present study was to synthesize and characterize high immunogenic W-1 L19 peptide (from the VP2 capsid protein of CPV) loaded PLGA nanoparticle and to evaluate their in vitro immunogenic activity. PLGA nanoparticles were produced with 5.26 ± 0.05 % loading capacity and high encapsulation efficiency with 81.2 ± 3.1 %. Additionally, it was evaluated that free NPs and W-1 L19 peptide encapsulated PLGA nanoparticles have Z-ave of 183.9 ± 12.1 nm, 221.7 ± 15.8 nm and polydispersity index of 0.107 ± 0.08, 0.135 ± 0.12 respectively. It was determined that peptide loaded PLGA nanoparticles were successfully phagocytized by macrophage cells and increased NO production at 2-folds (*P < 0.05) in contrast to free peptide, and 3-folds (*P < 0.01) in contrast to control. In conclusion, for the first time, W-1 L19 peptide loaded PLGA nanoparticles were successfully synthesized and immunogenic properties evaluated. Obtained results showed that PLGA nanoparticles enhanced the capacity of W-1 L19 peptide to induce nitric oxide production in vitro due to its adjuvant properties. Depend on the obtained results, these nanoparticles can be accepted as potential vaccine candidate against Canine Parvovirus. Studies targeting PLGA nanoparticles based delivery system must be maintained in near
Wu, Yanping; Wang, Zhongyuan; Liu, Gan; Zeng, Xiaowei; Wang, Xusheng; Gao, Yongfeng; Jiang, Lijuan; Shi, Xiaojun; Tao, Wei; Huang, Laiqiang; Mei, Lin
A novel nanocarrier system of cholic acid (CA) core, star-shaped polymer consisting of poly(D,L-lactide-co-glycolide) (PLGA) was developed for sustained and controlled delivery of simvastatin for chemotherapy of breast adenocarcinoma. The star-shaped polymer CA-PLGA with three branch arms was synthesized successfully through the core-first approach. The simvastatin-loaded star-shaped CA-PLGA nanoparticles were prepared through a modified nanoprecipitation method. The data showed that the fluorescence star-shaped CA-PLGA nanoparticles could be internalized into MDA-MB-231 and MDA-MB-468 human breast cancer cells. The simvastatin-loaded star-shaped CA-PLGA nanoparticles achieved significantly higher level of cytotoxicity than pristine simvastatin and simvastatin-loaded linear PLGA nanoparticles. Moreover, the expression of the cell cycle protein cyclin D1 was dramatically inhibited by simvastatin in both cells, with simvastatin-loaded star-shaped CA-PLGA nanoparticles having the greatest effect. MDA-MB-231 xenograft tumor model on BALB/c nude mice showed that simvastatin-loaded star-shaped CA-PLGA nanoformulations could effectively inhibit the growth of tumor over a longer period of time than pristine simvastatin and simvastatin-loaded linear PLGA nanoformulations at the same dose. In agreement with these, the nuclear expression of proliferation marker Ki-67 in simvastatin-loaded star-shaped CA-PLGA nanoparticles group was reduced to a most extent among four groups through tumor frozen section immunohistochemistry. In conclusion, the star-shaped CA-PLGA polymers could serve as a novel polymeric nanocarrier for breast cancer chemotherapy.
Ma, Hecheng; He, Chaoliang; Cheng, Yilong; Li, Dongsong; Gong, Yubao; Liu, Jianguo; Tian, Huayu; Chen, Xuesi
Combination cancer therapy has emerged as crucial approach for achieving superior anti-cancer efficacy. In this study, we developed a strategy by localized co-delivery of PLK1shRNA/polylysine-modified polyethylenimine (PEI-Lys) complexes and doxorubicin (DOX) using biodegradable, thermosensitive PLGA-PEG-PLGA hydrogels for treatment of osteosarcoma. When incubated with osteosarcoma Saos-2 and MG-63 cells, the hydrogel containing PLK1shRNA/PEI-Lys and DOX displayed significant synergistic effects in promoting the apoptosis of osteosarcoma cells in vitro. After subcutaneous injection of the hydrogel containing PLK1shRNA/PEI-Lys and DOX beside the tumors of nude mice bearing osteosarcoma Saos-2 xenografts, the hydrogels exhibited superior antitumor efficacy in vivo compared to the hydrogels loaded with PLK1shRNA/PEI-Lys or DOX alone. It is noteworthy that the combination treatment in vivo led to almost complete suppression of tumor growth up to 16 days, significantly enhanced PLK1 silencing, higher apoptosis of tumor masses, as well as increased cell cycle regulation. Additionally, ex vivo histological analysis of major organs of the mice indicated that the localized treatments showed no obvious damage to the organs, suggesting lower systemic toxicity of the treatments. Therefore, the strategy of localized, sustained co-delivery of PLK1shRNA and DOX by using the biodegradable, injectable hydrogel may have potential for efficient clinical treatment of osteosarcoma. Copyright © 2014 Elsevier Ltd. All rights reserved.
Gao, Meng; Xu, Hong; Bao, Xu; Zhang, Chenghong; Guan, Xin; Liu, Hongyan; Lv, Li; Deng, Sa; Gao, Dongyan; Wang, Changyuan; Tian, Yan
Heparin sodium (HS)-loaded polylactic-co-glycolic acid-D-α-tocopheryl polyethylene glycol 1000 succinate (PLGA-TPGS) nanoparticles (HPTNs) were prepared as sustained and targeted delivery carriers and combined with oleanolic acid (OA)-loaded PLGA-TPGS nanoparticles (OPTNs) that had been investigated in our previous work to form a combination therapy system for the treatment of liver cancer. To inspect cellular uptake and evaluate liver-targeting performance by analysing drug concentrations and cryosections, fluorescent probe coumarin-6 and eosin was used in preparations of HS/eosin-loaded, HS/coumarin-6-loaded, and OA/coumarin-6-loaded PLGA-TPGS nanoparticles. All of these NPs were characterized in terms of size, size distribution, surface charge, drug loading, encapsulation efficiency, and in vitro release profile. The apoptosis of HepG2 cells induced by OPTNs combined with HPTNs was determined by Annexin V-FITC staining and PI labelling. Transmission electron microscopy indicated that all of the nanoparticles were stably dispersed spheres with diameters ranging from 100 to 200nm. The results demonstrated that fluorescent nanoparticles were efficiently internalized into HepG2 and HCa-F cells, and that they exhibited enhanced liver targeting. The combination of HPTNs and OPTNs resulted in effective cell inhibition in vitro and a remarkable synergistic anticancer effect in vivo. The cell apoptosis results indicated that OPTNs combined with HPTNs could induce HepG2 cell apoptosis and exert synergistic effects. In vivo pharmacodynamics analysis using a solid tumour-bearing mouse model indicated that OPTNs combined with HPTNs could suppress tumour growth by 67.61%. This research suggests that the combined therapy system of OPTNs and HPTNs could be a new means of hepatoma therapy. Copyright © 2016 Elsevier Inc. All rights reserved.
Moraes Moreira Carraro, T C; Altmeyer, C; Maissar Khalil, N; Mara Mainardes, R
Amphotericin B (AmB) is widely applied in treatment of systemic fungal infections. However, the emergence of severe adverse effects, such as nephrotoxicity, hepatotoxicity and hemolytic anemia, can limit its clinical use. Poly(lactide-co-glycolide) (PLGA) or poly(lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) blend nanoparticles containing AmB were developed with the aim to decrease AmB toxicity and propose the oral route for AmB delivery. Nanoparticles were characterized by particle size, polydispersity index, Fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray diffraction analyses. The antifungal activity was evaluated against strains of Candida albicans and Cryptococcus neoformans. Toxicity was evaluated by hemolysis assay and after 7 days treatment in rats. Mean nanoparticle size was below 200nm with low polydispersity and AmB encapsulation efficiency higher than 90%. Nanoencapsulation resulted in AmB amorphization and no chemical interaction between drug and polymer. In C. albicans, minimum inhibitory concentration (MIC) of AmB-loaded PLGA-PEG nanoparticles was 2-fold higher than free AmB or marketed deoxycholate AmB (AmB-D), while MIC of AmB-loaded PLGA nanoparticles was 10-fold higher than AmB-loaded PLGA-PEG. In C. neoformans, the efficacy of AmB-loaded PLGA nanoparticles was comparable to free AmB, while AmB-loaded PLGA-PEG nanoparticles and AmB-D did not present MIC in tested concentration range. Nanoparticles inhibited the AmB-induced hemolysis. After 7 days treatment in rats, histologic examination revealed AmB-D treatment presented initial liver damage, while AmB-loaded nanoparticles did not present any hepatic cellular alteration. Kidney alteration was not observed in all treatments. Thus, PLGA and PLGA-PEG nanoparticles are promising carriers for AmB delivery with potential application in antifungal therapy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Sun, Ying; Zhu, Yunkai; Huang, Can; Li, Rongxin; Chen, Yaqing; Duan, Yourong
Magnetite loaded Polypeptide-PLGA multifunctional microbubbles (Fe3O4 /Polypeptide-PLGA MMBs) that show superparamagnetic properties were prepared by a modified double emulsion method and employed as imaging agent for dual-mode Ultrasound/Magnetic resonance (US/MR) imaging of prostatic cancer. The successful synthesis of MMBs was determined by Fourier Transform Infrared Spectrometer (FTIR), X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Atomic Absorption Spectroscopy (AAS) and vibrating sample magnetometer (VSM). The as-prepared MMBs had a diameter of 700 nm and were quite safe as confirmed by MTT assays. Prussian Blue Staining showed that targeted Fe3O4 /Polypeptide-PLGA MMBs enhanced the cellular uptake efficiency. In cell attachment study, adherence of MMBs was significantly higher to LNCaP cells compared with negative control PC3 cells. The in vitro results demonstrated that these MMBs could enhance both US and MR imaging of prostatic cancer.
Zhang, Hao-Xuan; Xiao, Gui-Yong; Wang, Xia; Dong, Zhao-Gang; Ma, Zhi-Yong; Li, Lei; Li, Yu-Hua; Pan, Xin; Nie, Lin
By utilizing a modified solid/oil/water (s/o/w) emulsion solvent evaporation technique, calcium phosphate composite scaffolds containing simvastatin-loaded PLGA microspheres (SIM-PLGA-CPC) were prepared in this study. We characterized the morphology, encapsulation efficiency and in vitro drug release of SIM-loaded PLGA microspheres as well as the macrostructure, pore size, porosity and mechanical strength of the scaffolds. Rabbit bone mesenchymal stem cells (BMSCs) were seeded onto SIM-PLGA-CPC scaffolds, and the proliferation, morphology, cell cycle and differentiation of BMSCs were investigated using the cell counting kit-8 (CCK-8) assay, scanning electron microscopy (SEM), flow cytometry, alkaline phosphatase (ALP) activity and alizarin red S staining, respectively. The results revealed that SIM-PLGA-CPC scaffolds were biocompatible and osteogenic in vitro. To determine the in vivo biocompatibility and osteogenesis of the scaffolds, both pure PLGA-CPC scaffolds and SIM-PLGA-CPC scaffolds were implanted in rabbit femoral condyles and microradiographically and histologically investigated. SIM-PLGA-CPC scaffolds exhibited good biocompatibility and could improve the efficiency of new bone formation. All these results suggested that the SIM-PLGA-CPC scaffolds fulfilled the basic requirements of bone tissue engineering scaffold and possessed application potentials in orthopedic surgery. © 2015 Wiley Periodicals, Inc.
Zhang, Yu; Zhou, Jun; Guo, Dajing; Ao, Meng; Zheng, Yuanyi; Wang, Zhigang
Thrombotic disease is a leading cause of death and disability worldwide. The development of magnetic resonance molecular imaging provides potential promise for early disease diagnosis. In this study, we explore the preparation and characterization of gadolinium (Gd)-loaded poly (lactic-co-glycolic acid) (PLGA) particles surface modified with the Arg-Gly-Asp-Ser (RGDS) peptide for the detection of thrombus. PLGA was employed as the carrier-delivery system, and a double emulsion solvent-evaporation method (water in oil in water) was used to prepare PLGA particles encapsulating the magnetic resonance contrast agent Gd diethylenetriaminepentaacetic acid (DTPA). To synthesize the Gd-PLGA/chitosan (CS)-RGDS particles, carbodiimide-mediated amide bond formation was used to graft the RGDS peptide to CS to form a CS-RGDS film that coated the surface of the PLGA particles. Blank PLGA, Gd-PLGA, and Gd-PLGA/CS particles were fabricated using the same water in oil in water method. Our results indicated that the RGDS peptide successfully coated the surface of the Gd-PLGA/CS-RGDS particles. The particles had a regular shape, smooth surface, relatively uniform size, and did not aggregate. The high electron density of the Gd-loaded particles and a translucent film around the particles coated with the CS and CS-RGDS films could be observed by transmission electron microscopy. In vitro experiments demonstrated that the Gd-PLGA/CS-RGDS particles could target thrombi and could be imaged using a clinical magnetic resonance scanner. Compared with the Gd-DTPA solution, the longitudinal relaxation time of the Gd-loaded particles was slightly longer, and as the Gd-load concentration increased, the longitudinal relaxation time values decreased. These results suggest the potential of the Gd-PLGA/CS-RGDS particles for the sensitive and specific detection of thrombus at the molecular level. PMID:24124363
Cooper, Dustin L.; Harirforoosh, Sam
Drug based nanoparticle (NP) formulations have gained considerable attention over the past decade for their use in various drug formulations. NPs have been shown to increase bioavailability, decrease side effects of highly toxic drugs, and prolong drug release. Nonsteroidal anti-inflammatory drugs such as diclofenac block cyclooxygenase expression and reduce prostaglandin synthesis, which can lead to several side effects such as gastrointestinal bleeding and renal insufficiency. The aim of this study was to formulate and characterize diclofenac entrapped poly(lactide-co-glycolide) (PLGA) based nanoparticles. Nanoparticles were formulated using an emulsion-diffusion-evaporation technique with varying concentrations of poly vinyl alcohol (PVA) (0.1, 0.25, 0.5, or 1%) or didodecyldimethylammonium bromide (DMAB) (0.1, 0.25, 0.5, 0.75, or 1%) stabilizers centrifuged at 8,800 rpm or 12,000 rpm. The resultant nanoparticles were evaluated based on particle size, zeta potential, and entrapment efficacy. DMAB formulated NPs showed the lowest particle size (108±2.1 nm) and highest zeta potential (−27.71±0.6 mV) at 0.1 and 0.25% respectively, after centrifugation at 12,000 rpm. Results of the PVA based NP formulation showed the smallest particle size (92.4±7.6 nm) and highest zeta potential (−11.14±0.5 mV) at 0.25% and 1% w/v, respectively, after centrifugation at 12,000 rpm. Drug entrapment reached 77.3±3.5% and 80.2±1.2% efficiency with DMAB and PVA formulations, respectively. The results of our study indicate the use of DMAB for increased nanoparticle stability during formulation. Our study supports the effective utilization of PLGA based nanoparticle formulation for diclofenac. PMID:24489896
Shankarayan, Raju; Kumar, Sumit; Mishra, Prashant
Piroxicam is a non-steroidal anti-inflammatory drug used for the treatment of musculoskeletal pain. The main problem encountered when piroxicam is administered orally is its gastric side-effect (ulcer, bleeding and holes in the stomach). Transmucosal delivery and encapsulation of piroxicam in biodegradable particles offer potential advantages over conventional oral delivery. The present study was aimed to develop an alternative to piroxicam-delivery which could overcome the direct contact of the drug at the mucosal membrane and its permeation through the mucosal membrane was studied. To achieve this, the piroxicam was encapsulated in Poly (lactide- co-glycolide) (PLGA) microparticles (size 1-4 μm, encapsulation efficiency 80-85 %) and nanoparticles (size 151.6 ± 28.6 nm, encapsulation efficiency 92.17 ± 3.08 %). Various formulation process parameters were optimised for the preparation of piroxicam-loaded PLGA nanoparticles of optimal size and encapsulation efficiency. Transmucosal permeability of piroxicam-loaded PLGA micro- and nanoparticles through the porcine oesophageal mucosa was studied. Using fluorescently labelled PLGA micro- and nanoparticles, size-dependent permeation was demonstrated. Furthermore, the effect of different permeation enhancers on the flux rate and permeability coefficient for the permeation of nanoparticles was investigated. The results suggested that amongst the permeation enhancers used the most efficient enhancement of permeation was observed with 10 mM sodium dodecyl sulphate.
Shin, Yong Cheol; Yang, Won Jun; Lee, Jong Ho; Oh, Jin-Woo; Kim, Tai Wan; Park, Jong-Chul; Hyon, Suong-Hyu; Han, Dong-Wook
This study concentrates on the development of biodegradable nanofiber membranes with controlled drug release to ensure reduced tissue adhesion and accelerated healing. Nanofibers of poly(lactic-co-glycolic acid) (PLGA) loaded with epigallocatechin-3-O-gallate (EGCG), the most bioactive polyphenolic compound in green tea, were electrospun. The physicochemical and biomechanical properties of EGCG-releasing PLGA (E-PLGA) nanofiber membranes were characterized by atomic force microscopy, EGCG release and degradation profiles, and tensile testing. In vitro antioxidant activity and hemocompatibility were evaluated by measuring scavenged reactive oxygen species levels and activated partial thromboplastin time, respectively. In vivo antiadhesion efficacy was examined on the rat peritonea with a surgical incision. The average fiber diameter of E-PLGA membranes was approximately 300-500 nm, which was almost similar to that of pure PLGA equivalents. E-PLGA membranes showed sustained EGCG release mediated by controlled diffusion and PLGA degradation over 28 days. EGCG did not adversely affect the tensile strength of PLGA membranes, whereas it significantly decreased the elastic modulus and increased the strain at break. E-PLGA membranes were significantly effective in both scavenging reactive oxygen species and extending activated partial thromboplastin time. Macroscopic observation after 1 week of surgical treatment revealed that the antiadhesion efficacy of E-PLGA nanofiber membranes was significantly superior to those of untreated controls and pure PLGA equivalents, which was comparable to that of a commercial tissue-adhesion barrier. In conclusion, the E-PLGA hybrid nanofiber can be exploited to craft strategies for the prevention of postsurgical adhesions.
Shin, Yong Cheol; Yang, Won Jun; Lee, Jong Ho; Oh, Jin-Woo; Kim, Tai Wan; Park, Jong-Chul; Hyon, Suong-Hyu; Han, Dong-Wook
This study concentrates on the development of biodegradable nanofiber membranes with controlled drug release to ensure reduced tissue adhesion and accelerated healing. Nanofibers of poly(lactic-co-glycolic acid) (PLGA) loaded with epigallocatechin-3-O-gallate (EGCG), the most bioactive polyphenolic compound in green tea, were electrospun. The physicochemical and biomechanical properties of EGCG-releasing PLGA (E-PLGA) nanofiber membranes were characterized by atomic force microscopy, EGCG release and degradation profiles, and tensile testing. In vitro antioxidant activity and hemocompatibility were evaluated by measuring scavenged reactive oxygen species levels and activated partial thromboplastin time, respectively. In vivo antiadhesion efficacy was examined on the rat peritonea with a surgical incision. The average fiber diameter of E-PLGA membranes was approximately 300–500 nm, which was almost similar to that of pure PLGA equivalents. E-PLGA membranes showed sustained EGCG release mediated by controlled diffusion and PLGA degradation over 28 days. EGCG did not adversely affect the tensile strength of PLGA membranes, whereas it significantly decreased the elastic modulus and increased the strain at break. E-PLGA membranes were significantly effective in both scavenging reactive oxygen species and extending activated partial thromboplastin time. Macroscopic observation after 1 week of surgical treatment revealed that the antiadhesion efficacy of E-PLGA nanofiber membranes was significantly superior to those of untreated controls and pure PLGA equivalents, which was comparable to that of a commercial tissue-adhesion barrier. In conclusion, the E-PLGA hybrid nanofiber can be exploited to craft strategies for the prevention of postsurgical adhesions. PMID:25187710
Aravind, Athulya; Nair, Remya; Raveendran, Sreejith; Veeranarayanan, Srivani; Nagaoka, Yutaka; Fukuda, Takahiro; Hasumura, Takahashi; Morimoto, Hisao; Yoshida, Yasuhiko; Maekawa, Toru; Sakthi Kumar, D.
Controlled and targeted drug delivery is an essential criterion in cancer therapy to reduce the side effects caused by non-specific drug release and toxicity. Targeted chemotherapy, sustained drug release and optical imaging have been achieved using a multifunctional nanocarrier constructed from poly (D, L-lactide-co-glycolide) nanoparticles (PLGA NPs), an anticancer drug paclitaxel (PTX), a fluorescent dye Nile red (NR), magnetic fluid (MF) and aptamers (Apt, AS1411, anti-nucleolin aptamer). The magnetic fluid and paclitaxel loaded fluorescently labeled PLGA NPs (MF-PTX-NR-PLGA NPs) were synthesized by a single-emulsion technique/solvent evaporation method using a chemical cross linker bis (sulfosuccinimidyl) suberate (BS3) to enable binding of aptamer on to the surface of the nanoparticles. Targeting aptamers were then introduced to the particles through the reaction with the cross linker to target the nucleolin receptors over expressed on the cancer cell surface. Specific binding and uptake of the aptamer conjugated magnetic fluid loaded fluorescently tagged PLGA NPs (Apt-MF-NR-PLGA NPs) to the target cancer cells induced by aptamers was observed using confocal microscopy. Cytotoxicity assay conducted in two cell lines (L929 and MCF-7) confirmed that targeted MCF-7 cancer cells were killed while control cells were unharmed. In addition, aptamer mediated delivery resulting in enhanced binding and uptake to the target cancer cells exhibited increased therapeutic effect of the drug. Moreover, these aptamer conjugated magnetic polymer vehicles apart from actively transporting drugs into specifically targeted tumor regions can also be used to induce hyperthermia or for facilitating magnetic guiding of particles to the tumor regions.
Van de Ven, H; Vermeersch, M; Vandenbroucke, R E; Matheeussen, A; Apers, S; Weyenberg, W; De Smedt, S C; Cos, P; Maes, L; Ludwig, A
Drug delivery systems present an opportunity to potentiate the therapeutic effect of antileishmanial drugs. Colloidal carriers are rapidly cleared by the phagocytic cells of the reticuloendothelial system (RES), rendering them ideal vehicles for passive targeting of antileishmanials. This paper describes the development of poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) for the antileishmanial saponin β-aescin. NPs were prepared using the combined emulsification solvent evaporation/salting-out technique. Confocal microscopy was used to visualise the internalisation and intracellular trafficking of fluorescein- and nile red-labelled PLGA NPs in J774A.1 macrophages infected with GFP-transfected Leishmania donovani. The in vitro activity of aescin and aescin-loaded NPs on L. infantum was determined in the axenic model as well as in the ex vivo model. The developed PLGA NPs were monodispersed with Z(ave)<300 nm, exhibited negative zeta potentials and had relatively high drug loadings ranging from 5.80 to 8.68% w/w PLGA. The fluorescent NPs were internalised by the macrophages and trafficked towards the lysosomes after 2 h in vitro incubation. Co-localisation of the NPs and the parasite was not shown. A two-fold increase in activity was observed in the ex vivo macrophage model by encapsulating β-aescin in PLGA NPs (IC(50), 0.48-0.76 µg/mL vs. 1.55 ± 0.32 µg/mL for the free drug).
Tong, Gui-Feng; Qin, Nan; Sun, Li-Wei
Depression is a debilitating psychiatric condition that remains the second most common cause of disability worldwide. Currently, depression affects more than 4 per cent of the world's population. Most of the drugs intended for clinical management of depression augment the availability of neurotransmitters at the synapse by inhibiting their neuronal reuptake. However, the therapeutic efficacy of antidepressants is often compromised as they are unable to reach brain by the conventional routes of administration. The purpose of the present study was to reconnoiter the potential of mucoadhesive PLGA-chitosan nanoparticles for the delivery of encapsulated Desvenlafaxine to the brain by nose to brain delivery route for superior pharmacokinetic and pharmacodynamic profile of Desvenlafaxine. Desvenlafaxine loaded PLGA-chitosan nanoparticles were prepared by solvent emulsion evaporation technique and optimized for various physiochemical characteristics. The antidepressant efficacy of optimized Desvenlafaxine was evaluated in various rodent depression models together with the biochemical estimation of monoamines in their brain. Further, the levels of Desvenlafaxine in brain and blood plasma were determined at various time intervals for calculation of different pharmacokinetic parameters. The optimized Desvenlafaxine loaded PLGA-chitosan nanoparticles (∼172 nm/+35 mV) on intranasal administration significantly reduced the symptoms of depression and enhanced the level of monoamines in the brain in comparison with orally administered Desvenlafaxine. Nose to brain delivery of Desvenlafaxine PLGA-chitosan nanoparticles also enhanced the pharmacokinetic profile of Desvenlafaxine in brain together with their brain/blood ratio at different time points. Thus, intranasal mucoadhesive Desvenlafaxine PLGA-chitosan nanoparticles could be potentially used for the treatment of depression.
The aim of this study was to formulate and characterize streptomycin-loaded PLGA-alginate nanoparticles for their potential therapeutic use in Salmonella subsp. enterica ATCC 14028 infections. The streptomycin nanoparticle was prepared by solvent diffusion method, and the other properties such as size, zeta potential, loading efficacy, release kinetics, and antimicrobial strength were evaluated. The survey shows that nanoparticles may serve as a carrier of streptomycin and may provide localized antibacterial activity in the treatment of Salmonellosis. Electron microscopy showed spherical particles with indentations. The average size of the nanoparticles was 90 nm. At pH 7.2, the release kinetics of streptomycin from the nanoparticles was successfully illustrated as an initial burst defined by a first order equation that after this stage, it has a drastic tendency to obtain steady state. Nevertheless, nanoparticles showed loading efficacy nearly about 70-75 %. In addition, the tendency of concentration of streptomycin released from nanoparticles to reach antibacterial activity was similar to that of free streptomycin against PLGA-alginate, but it had threefold more antimicrobial strength in comparison with free streptomycin. This work shows the potential use of streptomycin-loaded PLGA-alginate nanoparticles and its capability.
The aim of this study was to formulate and characterize streptomycin-loaded PLGA-alginate nanoparticles for their potential therapeutic use in Salmonella subsp. enterica ATCC 14028 infections. The streptomycin nanoparticle was prepared by solvent diffusion method, and the other properties such as size, zeta potential, loading efficacy, release kinetics, and antimicrobial strength were evaluated. The survey shows that nanoparticles may serve as a carrier of streptomycin and may provide localized antibacterial activity in the treatment of Salmonellosis. Electron microscopy showed spherical particles with indentations. The average size of the nanoparticles was 90 nm. At pH 7.2, the release kinetics of streptomycin from the nanoparticles was successfully illustrated as an initial burst defined by a first order equation that after this stage, it has a drastic tendency to obtain steady state. Nevertheless, nanoparticles showed loading efficacy nearly about 70-75 %. In addition, the tendency of concentration of streptomycin released from nanoparticles to reach antibacterial activity was similar to that of free streptomycin against PLGA-alginate, but it had threefold more antimicrobial strength in comparison with free streptomycin. This work shows the potential use of streptomycin-loaded PLGA-alginate nanoparticles and its capability.
Wang, S L; Xie, S Y; Zhu, L Y; Wang, F H; Zhou, W Z
Poly (lactic-co-glycolic acid) (PLGA) was used as a co-emulsifier in the preparation of insulin-loaded solid lipid nanoparticles (SLN) with hydrogenated castor oil as lipid matrix and lecithin as surfactant by double-emulsion technique. The effects of PLGA on the preparation and hypoglycaemic activity of insulin-loaded SLN were studied. The results showed that with the supplement of PLGA, the encapsulation efficiency and loading capacity were increased significantly from 79.08 +/- 1.62 to 85.57 +/- 3.21% and 1.58 +/- 0.03 to 1.71 +/- 0.06%, whereas the surface charge and particle size were changed insignificantly from -25.87 +/- 2.65 to -22.67 +/- 1.19 mv and 431.0 +/- 16.1 to 397.0 +/- 68.0 nm, respectively. In vivo studies demonstrated that PLGA increased the sustained hypoglycaemic activity from 12 to 36 h and 24 to 120 h in normal and steptozotocin-induced diabetic mice after a single intramuscular injection of the insulin-loaded SLN. These results demonstrated that PLGA could enhance the entrapment of insulin in the nanoparticles, and more importantly, prolong the time of hypoglycaemic activity of the insulin-loaded SLN.
Giarra, Simona; Serri, Carla; Russo, Luisa; Zeppetelli, Stefania; De Rosa, Giuseppe; Borzacchiello, Assunta; Biondi, Marco; Ambrosio, Luigi; Mayol, Laura
The arrangement of tumor targeting hyaluronic acid (HA) moieties on irinotecan (IRIN)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) has been directed by means of a gradient of lipophilicity between the oil and water phases of the emulsion used to produce the NPs. PLGA constitutes the NP bulk while HA is superficially exposed, with amphiphilic poloxamers acting as a bridge between PLGA and HA. Differential scanning calorimetry, zeta potential analyses and ELISA tests were employed to support the hypothesis of polymer assembly in NP formulations. The presence of flexible HA chains on NP surface enhances NP size stability over time due to an increased electrostatic repulsion between NPs and a higher degree of hydration of the device surface. IRIN in vitro release kinetics can be sustained up to 7-13 days. In vitro biologic studies indicated that HA-containing NPs were more toxic than bare PLGA NPs against CD44-overexpressing breast carcinoma cells (HS578T), therefore indicating their ability to target CD44 receptor.
TEFAS, LUCIA RUXANDRA; TOMUŢĂ, IOAN; ACHIM, MARCELA; VLASE, LAURIAN
Background and aims Quercetin is a flavonoid with good antioxidant activity, and exhibits various important pharmacological effects. The aim of the present work was to study the influence of formulation factors on the physicochemical properties of quercetin-loaded polymeric nanoparticles in order to optimize the formulation. Materials and methods The nanoparticles were prepared by the nanoprecipitation method. A 3-factor, 3-level Box-Behnken design was employed in this study considering poly(D,L-lactic-co-glycolic) acid (PLGA) concentration, polyvinyl alcohol (PVA) concentration and the stirring speed as independent variables. The responses were particle size, polydispersity index, zeta potential and encapsulation efficiency. Results The PLGA concentration seemed to be the most important factor influencing quercetin-nanoparticle characteristics. Increasing PLGA concentration led to an increase in particle size, as well as encapsulation efficiency. On the other hand, it exhibited a negative influence on the polydispersity index and zeta potential. The PVA concentration and the stirring speed had only a slight influence on particle size and polydispersity index. However, PVA concentration had an important negative effect on the encapsulation efficiency. Based on the results obtained, an optimized formulation was prepared, and the experimental values were comparable to the predicted ones. Conclusions The overall results indicated that PLGA concentration was the main factor influencing particle size, while entrapment efficiency was predominantly affected by the PVA concentration. PMID:26528074
Qiao, Tiankui; Jiang, Suchen; Song, Ping; Song, Xiaofeng; Liu, Qimin; Wang, Lijuan; Chen, Xuesi
Electropsun poly (lactide-co-glycolide) (PLGA) fiber membrane loaded xanthohumol (XN) has been developed using a co-solvent system of chloroform and dimethylformamide. To enhance its biological functionality as bone tissue engineering scaffolds, 5wt% hydroxyapatite grafted poly (l-lactic acid) (HA-g-PLLA) is blended into the spinning solution. The purpose of the present work is to disclose the effect of blending HA-g-PLLA on the corresponding properties of the medicated fiber membrane including morphology, thermodynamics, wettability, drug release, mechanics as well as cytotoxicity. XN and HA-g-PLLA can be well blended with PLGA to make fibers. Blending HA-g-PLLA not only turns amorphous XN/PLGA fiber membrane into crystal structure, but also changes the membranous wettability. Various medicated membranes exhibit the sustained release profiles. Drug release rate of the ternary membrane with HA-g-PLLA is slower compared to the binary XN/PLGA, and for the ternary membrane, the drug release accelerates with increasing XN content. A model is proposed to account for the drug release process. Tensile testing shows that at 10% of XN, the comprehensive mechanics of the ternary is preferable to the binary. At the same time, these fiber membranes are no cytotoxicity.
Rietscher, René; Czaplewska, Justyna A; Majdanski, Tobias C; Gottschaldt, Michael; Schubert, Ulrich S; Schneider, Marc; Lehr, Claus-Michael
The effect of modifying the well-established pharmaceutical polymer PLGA by different PEG-containing block-copolymers on the preparation of ovalbumin (OVA) loaded PLGA nanoparticles (NPs) was studied. The used polymers contained poly(d,l-lactic-co-glycolic acid) (PLGA), polyethylene glycol (PEG) and poly(allyl glycidyl ether) (PAGE) as building blocks. The double emulsion technique yielded spherical NPs in the size range from 170 to 220 nm (PDI<0.15) for all the differently modified polymers, allowing to directly compare protein loading of and release. PEGylation is usually believed to increase the hydrophilic character of produced particles, favoring encapsulation of hydrophilic substances. However, in this study simple PEGylation of PLGA had only a slight effect on protein release. In contrast, incorporating a PAGE block between the PEG and PLGA units, also eventually enabling active targeting introducing a reactive group, led to a significantly higher loading (+25%) and release rate (+100%), compared to PLGA and PEG-b-PLGA NPs.
Morales-Cruz, Moraima; Flores-Fernández, Giselle M.; Morales-Cruz, Myreisa; Orellano, Elsie A.; Rodriguez-Martinez, José A.; Ruiz, Mercedes; Griebenow, Kai
One of the first methods to encapsulate drugs within polymer nanospheres was developed by Fessi and coworkers in 1989 and consisted of one-step nanoprecipitation based on solvent displacement. However, proteins are poorly encapsulated within polymer nanoparticles using this method because of their limited solubility in organic solvents. To overcome this limitation, we developed a two-step nanoprecipitation method and encapsulated various proteins with high efficiency into poly(lactic-co-glycolic)acid (PLGA) nanospheres (NP). In this method, a protein nanoprecipitation step is used first followed by a second polymer nanoprecipitation step. Two model enzymes, lysozyme and α-chymotrypsin, were used for the optimization of the method. We obtained encapsulation efficiencies of >70%, an amount of buffer-insoluble protein aggregates of typically <2%, and a high residual activity of typically >90%. The optimum conditions identified for lysozyme were used to successfully encapsulate cytochrome c(Cyt-c), an apoptosis-initiating basic protein of similar size, to verify reproducibility of the encapsulation procedure. The size of the Cyt-c loaded-PLGA nanospheres was around 300–400 nm indicating the potential of the delivery system to passively target tumors. Cell viability studies, using a human cervical cancer cell line (HeLa), demonstrate excellent biocompatibility of the PLGA nanoparticles. PLGA nanoparticles carrying encapsulated Cyt-c were not efficient in causing apoptosis presumably because PLGA nanoparticles are not efficiently taken up by the cells. Future systems will have to be optimized to ascertain efficient cellular uptake of the nanoparticles by, e.g., surface modification with receptor ligands. PMID:23316451
Ma, Guilei; Zhang, Chao; Zhang, Linhua; Sun, Hongfan; Song, Cunxian; Wang, Chun; Kong, Deling
Star-shaped block copolymers based on poly(D,L-lactide-co-glycolide) (PLGA) and poly(ethylene glycol) (PEG) (st-PLGA-PEG) were synthesized with structural variation on arm numbers in order to investigate the relationship between the arm numbers of st-PLGA-PEG copolymers and their micelle properties. st-PLGA-PEG copolymers with arm numbers 3, 4 and 6 were synthesized by using different cores such as trimethylolpropane, pentaerythritol and dipentaerythritol, and were characterized by nuclear magnetic resonance and gel permeation chromatography. The critical micelle concentration decreased with increasing arm numbers in st-PLGA-PEG copolymers. The doxorubicin-loaded st-PLGA-PEG micelles were prepared by a modified nanoprecipitation method. Micellar properties such as particle size, drug loading content and in vitro drug release behavior were investigated as a function of the number of arms and compared with each other. The doxorubicin-loaded 4-arm PLGA-PEG micelles were found to have the highest cellular uptake efficiency and cytotoxicity compared with 3-arm PLGA-PEG micelles and 6-arm PLGA-PEG micelles. The results suggest that structural tailoring of arm numbers from st-PLGA-PEG copolymers could provide a new strategy for designing drug carriers of high efficiency. Structural tailoring of arm numbers from star shaped-PLGA-PEG copolymers (3-arm/4-arm/6-arm-PLGA-PEG) could provide a new strategy for designing drug carriers of high efficiency.
Gentile, Piergiorgio; Nandagiri, Vijay Kumar; Pabari, Ritesh; Daly, Jacqueline; Tonda-Turo, Chiara; Ciardelli, Gianluca; Ramtoola, Zebunnissa
Biodegradable poly(lactide-co-glycolide) (PLGA) nanoparticles, containing human parathyroid hormone (PTH (1–34)), prepared by a modified double emulsion-solvent diffusion-evaporation method, were incorporated in porous freeze-dried chitosan-gelatin (CH-G) scaffolds. The PTH-loaded nanoparticles (NPTH) were characterised in terms of morphology, size, protein loading, release kinetics and in vitro assessment of biological activity of released PTH and cytocompatibility studies against clonal human osteoblast (hFOB) cells. Structural integrity of incorporated and released PTH from nanoparticles was found to be intact by using Tris-tricine SDS-PAGE. In vitro PTH release kinetics from PLGA nanoparticles were characterised by a burst release followed by a slow release phase for 3–4 weeks. The released PTH was biologically active as evidenced by the stimulated release of cyclic AMP from hFOB cells as well as increased mineralisation studies. Both in vitro and cell studies demonstrated that the PTH bioactivity was maintained during the fabrication of PLGA nanoparticles and upon release. Finally, a content of 33.3% w/w NPTHs was incorporated in CH-G scaffolds, showing an intermittent release during the first 10 days and, followed by a controlled release over 28 days of observation time. The increased expression of Alkaline Phosphatase levels on hFOB cells further confirmed the activity of intermittently released PTH from scaffolds. PMID:26343649
Zhang, Haiping; Xu, Jianfang
The objective of the current study was to prepare microspheres of salmeterol (SM) using poly (lactide-co-glycolide) (PLGA) and assess its viability to enhance the oral bioavailability. Microspheres of SM were prepared by oil-in-water emulsion-solvent evaporation method. The formulations were characterized in encapsulation efficiency, particle size, zeta potential, and in vitro release. The prepared microspheres were found to be spherical in shape with smooth surface. The size of microspheres ranged from 14.7 to 16.5 µm. The polydispersity index (PDI) was 0.12 ± 0.05 and the zeta potential was -33.2 ± 1.4 mV. In vitro release profile, SM was graduated released from the microspheres as time lapsed, suggesting that SM was well entrapped in SM-loaded PLGA microspheres. The model that fitted best for SM released from the microspheres was Higuchi equation. In vivo study, SM-loaded PLGA microspheres are thought to have the potential to maintain SM concentration within target ranges for a long time, decreasing side effects caused by concentration fluctuation, ensuring the efficiency of treatment and improving patient compliance by reducing dosing frequency.
Lee, Cheng-Hung; Chang, Shang-Hung; Chen, Wei-Jan; Hung, Kuo-Chun; Lin, Yu-Huang; Liu, Shih-Jung; Hsieh, Ming-Jer; Pang, Jong-Hwei S; Juang, Jyuhn-Huarng
This work developed nanofibrous drug-loaded collagen/poly-D-L-lactide-glycolide (PLGA) scaffold membranes that provided the sustained release of glucophage for the wounds associated with diabetes. PLGA, glucophage, and collagen were firstly dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol and were spun into nanofibrous membranes by electrospinning. High-performance liquid chromatography assay was used to characterize the in vivo and in vitro release rates of the pharmaceuticals from the membranes. High concentrations of glucophage were released for over three weeks from the nanofibrous membranes. The nanofibrous glucophage-loaded collagen/PLGA membranes were more hydrophilic than collagen/PLGA membranes and exhibited a greater water-containing capacity. The glucophage-loaded collagen/PLGA membranes markedly promoted the healing of diabetic wounds. Moreover, the collagen content of diabetic rats using drug-eluting membranes was higher than that of the control rats, because of the down-regulation of matrix metalloproteinase 9. The experimental results herein suggest that the nanofibrous glucophage-loaded collagen/PLGA membranes had effect for increasing collagen content in treating diabetic wounds and very effective promoters of the healing of such wounds in the early stages. Copyright © 2014 Elsevier Inc. All rights reserved.
Pillai, Gopikrishna J; Paul-Prasanth, Bindhu; Nair, Shantikumar V; Menon, Deepthy
In the present work, 2-Methoxyestradiol [2ME2] loaded PLGA nanoparticles [NPs] were stabilized with Casein or poly(ethylene glycol) [PEG] and evaluated for its cellular interactions, pharmacokinetics and tumour accumulation. Surface stabilized PLGA nanoparticles prepared through a modified emulsion route possessed similar size, surface charge, drug loading and release characteristics. Particle-cell interactions as well as the anti-angiogenesis activity were similar for both nanoformulations in vitro. However, in vivo pharmacokinetics and tumour accumulation of the drug were substantially improved for the PEGylated nanoformulation. Reduced protein binding was observed for PEG stabilized PLGA NPs. Thus, it was demonstrated that nanoencapsulation of 2-ME2 within PEGylated PLGA nanocarrier could improve its half-life and plasma concentration and thereby increase the tumour accumulation.
Wang, Yan J.; Strohm, Eric M.; Sun, Yang; Niu, Chengcheng; Zheng, Yuanyi; Wang, Zhigang; Kolios, Michael C.
Phase-change contrast agents consisting of a perfluorocarbon (PFC) liquid core stabilized by a lipid, protein, or polymer shell have been proposed for a variety of clinical applications. Previous work has demonstrated that vaporization can be induced by laser irradiation through optical absorbers incorporated inside the droplet. In this study, Poly-lactide-coglycolic acid (PLGA) particles loaded with PFC liquid and silica-coated gold nanoparticles (GNPs) were developed and characterized using photoacoustic (PA) methods. Microsized PLGA particles were loaded with PFC liquid and GNPs (14, 35, 55nm each with a 20nm silica shell) using a double emulsion method. The PA signal intensity and optical vaporization threshold were investigated using a 375 MHz transducer and a focused 532-nm laser (up to 450-nJ per pulse). The laser-induced vaporization threshold energy decreased with increasing GNP size. The vaporization threshold was 850, 690 and 420 mJ/cm2 for 5μm-sized PLGA particles loaded with 14, 35 and 55 nm GNPs, respectively. The PA signal intensity increased as the laser fluence increased prior to the vaporization event. This trend was observed for all particles sizes. PLGA particles were then incubated with MDA-MB-231 breast cancer cells for 6 hours to investigate passive targeting, and the vaporization of the PLGA particles that were internalized within cells. The PLGA particles passively internalized by MDA cells were visualized via confocal fluorescence imaging. Upon PLGA particle vaporization, bubbles formed inside the cells resulting in cell destruction. This work demonstrates that GNPs-loaded PLGA/PFC particles have potential as PA theranostic agents in PA imaging and optically-triggered drug delivery systems.
Jonderian, Antranik; Maalouf, Rita
This study aims to characterize rhodamine B (Rh B) loaded poly(D,L-lactide-co-glycolide; PLGA) nanoparticles (NPs) and their interactions with cardiac myocytes. PLGA NPs were formulated using single emulsion solvent evaporation technique. The influence of varying parameters such as the stabilizer concentration, the sonication time, and the organic to aqueous ratio were investigated. The diameter, the dispersity, the encapsulation efficiency and the zeta potential of the optimized NPs were about 184 nm, 0.19, 40% and -21.7 mV, respectively. In vitro release showed that 29% of the Rh B was released within the first 8 h. Scanning electron microscopy measurements performed on the optimized NPs showed smooth surface and spherical shapes. No significant cytotoxic or apoptotic effects were observed on cardiac myocytes after 24 and 48 h of exposure with concentrations up to 200 μg/mL. The kinetic of the intracellular uptake was confirmed by confocal microscopy and cells took up PLGA NPs within the 1st hours. Interestingly, our data show an increase in the NPs’ uptake with time of exposure. Taken together, we demonstrate for the first time that the designed NPs can be used as potential probes for drug delivery in cardiac myocytes. PMID:27999542
Venkatesh, D. Nagasamy; Baskaran, Mahendran; Karri, Veera Venkata Satyanarayana Reddy; Mannemala, Sai Sandeep; Radhakrishna, Kollipara; Goti, Sandip
Nelfinavir mesylate (NFV) is an anti-viral drug, used in the treatment of Acquired Immunodeficiency Syndrome (AIDS). Poor oral bioavailability and shorter half-life (3.5–5 h) remain a major clinical limitation of NFV leading to unpredictable drug bioavailability and frequent dosing. In this context, the objective of the present study was to formulate NFV loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs), which can increase the solubility and oral bioavailability along with sustained release of the drug. NFV loaded PLGA-NPs were prepared by nanoprecipitation method using PLGA and Poloxomer 407. The prepared NPs were evaluated for particle size, zeta potential, morphology, drug content, entrapment efficiency (EE) and in vitro dissolution studies. Oral bioavailability studies were carried out in New Zealand rabbits by administering developed NFV PLGA-NPs and pure drug suspension. PLGA-NPs prepared by using 1:4 ratio of drug and PLGA, with a stirring rate of 1500 rpm for 4 h. The prepared NPs were in the size of 185 ± 0.83 nm with a zeta potential of 28.7 ± 0.09 mV. The developed NPs were found to be spherical with uniform size distribution. The drug content and EE of the optimized formulation were found to be 36 ± 0.19% and 72 ± 0.47% respectively. After oral administration of NFV PLGA-NPs, the relative bioavailability was enhanced about 4.94 fold compared to NFV suspension as a control. The results describe an effective strategy for oral delivery of NFV loaded PLGA NPs that helps in enhancing bioavailability and reduce the frequency of dosing. PMID:26702262
Han, Felicity Y.; Thurecht, Kristofer J.; Whittaker, Andrew K.; Smith, Maree T.
Poly(lactic-co-glycolic acid) (PLGA) is the most widely used biomaterial for microencapsulation and prolonged delivery of therapeutic drugs, proteins and antigens. PLGA has excellent biodegradability and biocompatibility and is generally recognized as safe by international regulatory agencies including the United States Food and Drug Administration and the European Medicines Agency. The physicochemical properties of PLGA may be varied systematically by changing the ratio of lactic acid to glycolic acid. This in turn alters the release rate of microencapsulated therapeutic molecules from PLGA microparticle formulations. The obstacles hindering more widespread use of PLGA for producing sustained-release formulations for clinical use include low drug loading, particularly of hydrophilic small molecules, high initial burst release and/or poor formulation stability. In this review, we address strategies aimed at overcoming these challenges. These include use of low-temperature double-emulsion methods to increase drug-loading by producing PLGA particles with a small volume for the inner water phase and a suitable pH of the external phase. Newer strategies for producing PLGA particles with high drug loading and the desired sustained-release profiles include fabrication of multi-layered microparticles, nanoparticles-in-microparticles, use of hydrogel templates, as well as coaxial electrospray, microfluidics, and supercritical carbon dioxide methods. Another recent strategy with promise for producing particles with well-controlled and reproducible sustained-release profiles involves complexation of PLGA with additives such as polyethylene glycol, poly(ortho esters), chitosan, alginate, caffeic acid, hyaluronic acid, and silicon dioxide. PMID:27445821
Wang, Wenping; Cai, Yaqin; Zhang, Guangxing; Liu, Yanhua; Sui, Hong; Park, Kinam; Wang, Hong
Lung-targeting sophoridine-loaded poly(lactide-co-glycolide) (PLGA) microspheres were constructed by a simple oil-in-oil emulsion-solvent evaporation method. The obtained microspheres were systematically studied on their morphology, size distribution, drug loading, encapsulation efficiency, in vitro release profile, and biodistribution in rats. The drug-loaded microparticles showed as tiny spheres under SEM and had an average size of 17 μm with 90% of the microspheres ranging from 12 to 24 μm. The drug loading and encapsulation efficiency were 65% and 6.5%, respectively. The in vitro drug release behavior of microspheres exhibited an initial burst of 16.6% at 4 h and a sustained-release period of 14 days. Drug concentration in lung tissue of rats was 220.10 μg/g for microspheres and 6.77 μg/g for solution after intraveneous injection for 30 min, respectively. And the microsphere formulation showed a significantly higher drug level in lung tissue than in other major organs and blood samples for 12 days. These results demonstrated that the obtained PLGA microspheres could potentially improve the treatment efficacy of sophoridine against lung cancer.
Klippstein, Rebecca; Wang, Julie Tzu-Wen; El-Gogary, Riham I; Bai, Jie; Mustafa, Falisa; Rubio, Noelia; Bansal, Sukhvinder; Al-Jamal, Wafa T; Al-Jamal, Khuloud T
Clinical applications of curcumin for the treatment of cancer and other chronic diseases have been mainly hindered by its short biological half-life and poor water solubility. Nanotechnology-based drug delivery systems have the potential to enhance the efficacy of poorly soluble drugs for systemic delivery. This study proposes the use of poly(lactic-co-glycolic acid) (PLGA)-based polymeric oil-cored nanocapsules (NCs) for curcumin loading and delivery to colon cancer in mice after systemic injection. Formulations of different oil compositions are prepared and characterized for their curcumin loading, physico-chemical properties, and shelf-life stability. The results indicate that castor oil-cored PLGA-based NC achieves high drug loading efficiency (≈18% w(drug)/w(polymer)%) compared to previously reported NCs. Curcumin-loaded NCs internalize more efficiently in CT26 cells than the free drug, and exert therapeutic activity in vitro, leading to apoptosis and blocking the cell cycle. In addition, the formulated NC exhibits an extended blood circulation profile compared to the non-PEGylated NC, and accumulates in the subcutaneous CT26-tumors in mice, after systemic administration. The results are confirmed by optical and single photon emission computed tomography/computed tomography (SPECT/CT) imaging. In vivo growth delay studies are performed, and significantly smaller tumor volumes are achieved compared to empty NC injected animals. This study shows the great potential of the formulated NC for treating colon cancer. PMID:26140363
Qi, Yiying; Du, Yi; Li, Weixu; Dai, Xuesong; Zhao, Tengfei; Yan, Weiqi
The integration of regenerated cartilage with surrounding native cartilage is a major challenge for the success of cartilage tissue-engineering strategies. The purpose of this study is to investigate whether incorporation of the power of mesenchymal stem cell (MSC) sheet to MSCs-loaded bilayer poly-(lactic-co-glycolic acid) (PLGA) scaffolds can improve the integration and repair of cartilage defects in a rabbit model. Rabbit bone marrow-derived MSCs were cultured and formed cell sheet. Full-thickness cylindrical osteochondral defects (4 mm in diameter, 3 mm in depth) were created in the patellar groove of 18 New Zealand white rabbits and the osteochondral defects were treated with PLGA scaffold (n = 6), PLGA/MSCs (n = 6) or MSC sheet-encapsulated PLGA/MSCs (n = 6). After 6 and 12 weeks, the integration and tissue response were evaluated histologically. The MSC sheet-encapsulated PLGA/MCSs group showed significantly more amounts of hyaline cartilage and higher histological scores than PLGA/MSCs group and PLGA group (P < 0.05). In addition, the MSC sheet-encapsulated PLGA/MCSs group showed the best integration between the repaired cartilage and surrounding normal cartilage and subchondral bone compared to other two groups. The novel method of incorporation of MSC sheet to PLGA/MCSs could enhance the ability of cartilage regeneration and integration between repair cartilage and the surrounding cartilage. Transplantation of autologous MSC sheet combined with traditional strategies or cartilage debris might provide therapeutic opportunities for improving cartilage regeneration and integration in humans.
Park, Ji Sun; Yang, Han Na; Yi, Se Won; Kim, Jae-Hwan; Park, Keun-Hong
Several factors are involved in angiogenesis. To form new blood vessels, we fabricated vehicles carrying an angiogenesis-related peptide (apelin) and gene (vascular endothelial growth factor (VEGF)165) that were internalized by human mesenchymal stem cells (hMSCs). These non-toxic poly-(DL)-lactic-co-glycolic acid (PLGA) nanoparticles (NPs) easily entered hMSCs without cytotoxicity. The negatively charged outer surface of PLGA NPs can be easily complexed with highly positively charged polyethylenimine (PEI) to deliver genes into cells. PLGA NPs complexed with PEI could be coated with negatively charged VEGF plasmid DNA and loaded with apelin. The physical characteristics of these PLGA NPs were determined by size distribution, gel retardation, and morphological analyses. Transfection of VEGF-coated apelin-loaded PLGA NPs resulted in the differentiation of hMSCs into endothelial cells and vascular formation in Matrigel in vitro. Following injection of hMSCs transfected with these PLGA NPs into an ischemic hind limb mouse model, these cells differentiated into endothelial cells and accelerated neovascularization.
Rong, Zi-Jie; Yang, Lian-Jun; Cai, Bao-Ta; Zhu, Li-Xin; Cao, Yan-Lin; Wu, Guo-Feng; Zhang, Zan-Jie
To develop adriamycin (ADM)-encapsulated poly(lactic-co-glycolic acid) (PLGA) nanoparticles in a porous nano-hydroxyapatite/collagen scaffold (ADM-PLGA-NHAC). To provide novel strategies for future treatment of osteosarcoma, the properties of the scaffold, including its in vitro extended-release properties, the inhibition effects of ADM-PLGA-NHAC on the osteosarcoma MG63 cells, and its bone repair capacity, were investigated in vivo and in vitro. The PLGA copolymer was utilized as a drug carrier to deliver ADM-PLGA nanoparticles (ADM-PLGA-NP). Porous nano-hydroxyapatite and collagen were used to materials to produce the porous nano-hydroxyapatite/collagen scaffold (NHAC), into which the ADM-PLGA-NP was loaded. The performance of the drug-carrying scaffold was assessed using multiple techniques, including scanning electron microscopy and in vitro extended release. The antineoplastic activities of scaffold extracts on the human osteosarcoma MG63 cell line were evaluated in vitro using the cell counting kit-8 (CCK8) method and live-dead cell staining. The bone repair ability of the scaffold was assessed based on the establishment of a femoral condyle defect model in rabbits. ADM-PLGA-NHAC and NHAC were implanted into the rat muscle bag for immune response experiments. A tumor-bearing nude mice model was created, and the TUNEL and HE staining results were observed under optical microscopy to evaluate the antineoplastic activity and toxic side effects of the scaffold. The composite scaffold demonstrated extraordinary extended-release properties, and its extracts also exhibited significant inhibition of the growth of osteosarcoma MG63 cells. In the bone repair experiment, no significant difference was observed between ADM-PLGA-NHAC and NHAC by itself. In the immune response experiments, ADM-PLGA-NHAC exhibited remarkable biocompatibility. The in vivo antitumor experiment revealed that the implantation of ADM-PLGA-NHAC in the tumor resulted in a improved antineoplastic
Ray, Sayantan; Ghosh Ray, Suparna; Mandal, Supratim
In this study we report the development and optimization of poly (D, L-lactide-co-glycolide) (PLGA) polymer encapsulated poorly aqueous soluble nonsteroidal antiandrogen drug bicalutamide, to develop a sustained release formulation for the treatment of prostate cancer. The bicalutamide-loaded PLGA nanoparticles were prepared by single emulsion (O/W) solvent evaporation method, and different process parameters like polymer concentration in the organic phase, surfactant concentration in aqueous phase and centrifugation speed for separation of nanoparticles were evaluated to optimize the drug-loaded nanoparticles. The optimum formulation of bicalutamide-loaded PLGA nanoparticles characterized extensively by different analytical techniques like laser light scattering to determine average particle size and size distribution, scanning electron microscopy (SEM) for surface morphology, powder X-ray diffraction (PXRD) for surface chemistry and differential scanning calorimetry (DSC) for thermogram properties. Significant decrease of crystallinity of bicalutamide confirms entrapment of the drug within the PLGA polymer matrix. Further, the drug encapsulation efficiency (EE) and in vitro drug release profile were measured by high-performance liquid chromatography and UV-spectrophotometry. In vitro drug release exhibited biphasic pattern with initial burst release followed by slow and continuous release up to 5 days. Optimum formulation of bicalutamide-loaded PLGA nanoparticles shows significant anti-tumor activity over prostate cancer cell lines (DU 145). The newly developed optimum formulation nanoparticles could be useful for sustained release delivery of bicalutamide.
Zhu, Xianbing; Zeng, Xiaowei; Zhang, Xudong; Cao, Wei; Wang, Yilin; Chen, Houjie; Wang, Teng; Tsai, Hsiang-I; Zhang, Ran; Chang, Danfeng; He, Shuai; Mei, Lin; Shi, Xiaojun
Ultraviolet (UV) radiation has deleterious effects on living organisms, and functions as a tumor initiator and promoter. Multiple natural compounds, like quercetin, have been shown the protective effects on UV-induced damage. However, quercetin is extremely hydrophobic and limited by its poor percutaneous permeation and skin deposition. Here, we show that quercetin-loaded PLGA-TPGS nanoparticles could overcome low hydrophilicity of quercetin and improve its anti-UVB effect. Quercetin-loaded NPs can significantly block UVB irradiation induced COX-2 up-expression and NF-kB activation in Hacat cell line. Moreover, PLGA-TPGS NPs could efficiently get through epidermis and reach dermis. Treatment of mice with quercetin-loaded NPs also attenuates UVB irradiation-associated macroscopic and histopathological changes in mice skin. These results demonstrated that copolymer PLGA-TPGS could be used as drug nanocarriers against skin damage and disease. The findings provide an external use of PLGA-TPGS nanocarriers for application in the treatment of skin diseases. Skin is the largest organ in the body and is subjected to ultraviolet (UV) radiation damage daily from the sun. Excessive exposure has been linked to the development of skin cancer. Hence, topically applied agents can play a major role in skin protection. In this article, the authors developed quercetin-loaded PLGA-TPGS nanoparticles and showed their anti-UVB effect. Copyright © 2015 Elsevier Inc. All rights reserved.
Dillen, Kathleen; Vandervoort, Jo; Van den Mooter, Guy; Ludwig, Annick
The objective of present study was to prepare positively charged ciprofloxacin-loaded nanoparticles providing a controlled release formulation. The particles were prepared by water-in-oil-in-water (w/o/w) emulsification and solvent evaporation, followed by high-pressure homogenisation. Two non-biodegradable positively charged polymers, Eudragit RS100 and RL100, and the biodegradable polymer poly(lactic-co-glycolic acid) or PLGA were used alone or in combination, with varying ratios. The formulations were evaluated in terms of particle size and zeta potential. Differential scanning calorimetry measurements were carried out on the nanoparticles and on the pure polymers Eudragit and PLGA. Drug loading and release properties of the nanoparticles were examined. The antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus was determined. During solvent evaporation, the size and zeta potential of the nanoparticles did not change significantly. The mean diameter was dependent on the presence of Eudragit and on the viscosity of the organic phase. The zeta potential of all Eudragit containing nanoparticles was positive in ultrapure water (around +21/+25 mV). No burst effect but a prolonged drug release was observed from all formulations. The particles' activity against P. aeruginosa and S. aureus was comparable with an equally concentrated ciprofloxacin solution.
Keohane, Kieran; Brennan, Des; Galvin, Paul; Griffin, Brendan T
The increasing realisation of the impact of size and surface properties on the bio-distribution of drug loaded colloidal particles has driven the application of micro fabrication technologies for the precise engineering of drug loaded microparticles. This paper demonstrates an alternative approach for producing size controlled drug loaded PLGA based microparticles using silicon Microfluidic Flow Focusing Devices (MFFDs). Based on the precise geometry and dimensions of the flow focusing channel, microparticle size was successfully optimised by modifying the polymer type, disperse phase (Qd) flow rate, and continuous phase (Qc) flow rate. The microparticles produced ranged in sizes from 5 to 50 μm and were highly monodisperse (coefficient of variation <5%). A comparison of Ciclosporin (CsA) loaded PLGA microparticles produced by MFFDs vs conventional production techniques was also performed. MFFDs produced microparticles with a narrower size distribution profile, relative to the conventional approaches. In-vitro release kinetics of CsA was found to be influenced by the production technique, with the MFFD approach demonstrating the slowest rate of release over 7 days (4.99 ± 0.26%). Finally, MFFDs were utilised to produce pegylated microparticles using the block co-polymer, PEG-PLGA. In contrast to the smooth microparticles produced using PLGA, PEG-PLGA microparticles displayed a highly porous surface morphology and rapid CsA release, with 85 ± 6.68% CsA released after 24h. The findings from this study demonstrate the utility of silicon MFFDs for the precise control of size and surface morphology of PLGA based microparticles with potential drug delivery applications.
Kimishima, Kaori; Matsuno, Tomonori; Makiishi, Jun; Tamazawa, Gaku; Sogo, Yu; Ito, Atsuo; Satoh, Tazuko
Composites of gatifloxacin (GFLX)-loaded poly (lactic-co-glycolic) acid (PLGA) and β-tricalcium phosphate (βTCP) containing 0, 1, and 10 wt % GFLX (0, 1, and 10 wt % GFLX composites), and GFLX-loaded PLGA containing 1, 5, and 10 wt % GFLX (1, 5, and 10wt % GFLX-PLGA) as controls were fabricated and characterized in vitro and in vivo. On in vitro evaluation, the 10 wt % GFLX composite released GFLX over at least 28 days in Hanks' balanced solution and exhibited clinically sufficient bactericidal activities against Streptococcus milleri and Bacteroides fragilis from 1 h to 10 days. The 0, 1, and 10 wt % GFLX composites and 10 wt % GFLX-PLGA were implanted in bone defects created by debridement of osteomyelitis lesions induced by S. milleri and B. fragilis in the mandible of rabbits (n = 5). Four weeks after implantation of the 10 wt % GFLX composite, inflammation in the debrided area disappeared in all the rabbits, while inflammation remained in all the rabbits after implantation of the 0 wt % GFLX composite and 10 wt % GFLX-PLGA, and in three rabbits after implantation of the 1 wt % GFLX composite. Bone formation appears to be less intense for the 10 wt % GFLX composite than for the 1 wt % GFLX composite probably owing to the rapid degradation of the 10 wt % GFLX composite. These findings show that the GFLX composite is effective for the local treatment of osteomyelitis.
Tabatabaei Mirakabad, Fatemeh Sadat; Akbarzadeh, Abolfazl; Milani, Morteza; Zarghami, Nosratollah; Taheri-Anganeh, Mortaza; Zeighamian, Vahideh; Badrzadeh, Fariba; Rahmati-Yamchi, Mohammad
Breast cancer is the most commonly diagnosed cancer and the leading cause of cancer death among women worldwide. Herbal medicines have tremendous potential as promising agents for the treatment of cancer. Curcumin is a natural polyphenol which has many anticancer effects. Because of its low aqueous solubility, low bioavailability, and quick degradation and metabolism, curcumin was released using PLGA-PEG nanoparticles. Herein, the efficiency of pure curcumin and curcumin-loaded PLGA-PEG in MCF-7 human breast cancer cell lines was studied. (1)H NMR, FT-IR and SEM demonstrated PLGA-PEG structure and curcumin loaded on nanoparticles. Subsequently, the cytotoxic effects of free curcumin and curcumin-loaded PLGA-PEG were determined via an MTT assay. Our study confirmed that curcumin-loaded PLGA-PEG has more cytotoxic effects on the MCF-7 breast cancer cell line and could be exploited as a potential source for developing novel drugs against breast cancer.
Li, Yu-Hua; Wang, Zhen-Dong; Wang, Wei; Ding, Chang-Wei; Zhang, Hao-Xuan
The composite of poly-lactic-co-glycolic acid (PLGA) and calcium phosphate cements (CPC) are currently widely used in bone tissue engineering. However, the properties and biocompatibility of the alendronate-loaded PLGA/CPC (APC) porous scaffolds have not been characterized. APC scaffolds were prepared by a solid/oil/water emulsion solvent evaporation method. The morphology, porosity, and mechanical strength of the scaffolds were characterized. Bone marrow mesenchymal stem cells (BMSCs) from rabbit were cultured, expanded and seeded on the scaffolds, and the cell morphology, adhesion, proliferation, cell cycle and osteogenic differentiation of BMSCs were determined. The results showed that the APC scaffolds had a porosity of 67.43 ± 4.2% and pore size of 213 ± 95 µm. The compressive strength for APC was 5.79 ± 1.21 MPa, which was close to human cancellous bone. The scanning electron microscopy, cell counting kit-8 assay, flow cytometry and ALP activity revealed that the APC scaffolds had osteogenic potential on the BMSCs in vitro and exhibited excellent biocompatibility with engineered bone tissue. APC scaffolds exhibited excellent biocompatibility and osteogenesis potential and can potentially be used for bone tissue engineering. PMID:25877763
Albisa, Airama; Piacentini, Emma; Sebastian, Victor; Arruebo, Manuel; Santamaria, Jesus; Giorno, Lidietta
The aim of this work is to develop a scalable continuous system suitable for the formulation of polymeric nanoparticles using membrane-assisted nanoprecipitation. One of the hurdles to overcome in the use of nanostructured materials as drug delivery vectors is their availability at industrial scale. Innovation in process technology is required to translate laboratory production into mass production while preserving their desired nanoscale characteristics. Membrane-assisted nanoprecipitation has been used for the production of Poly[(D,L lactide-co-glycolide)-co-poly ethylene glycol] diblock) (PLGA-PEG) nanoparticles using a pulsed back-and-forward flow arrangement. Tubular Shirasu porous glass membranes (SPG) with pore diameters of 1 and 0.2 μm were used to control the mixing process during the nanoprecipitation reaction. The size of the resulting PLGA-PEG nanoparticles could be readily tuned in the range from 250 to 400 nm with high homogeneity (PDI lower than 0.2) by controlling the dispersed phase volume/continuous phase volume ratio. Dexamethasone was successfully encapsulated in a continuous process, achieving an encapsulation efficiency and drug loading efficiency of 50% and 5%, respectively. The dexamethasone was released from the nanoparticles following Fickian kinetics. The method allowed to produce polymeric nanoparticles for drug delivery with a high productivity, reproducibility and easy scalability.
Tamazawa, Gaku; Ito, Atsuo; Miyai, Takahiro; Matsuno, Tomonori; Kitahara, Kazuki; Sogo, Yu; Kimishima, Kaori; Satoh, Tazuko
Gatifloxacine (GFLX)-containing poly(lactide-co-glycolide) (PLGA) was introduced to the pores and surfaces of porous β-tricalcium phosphate (βTCP) granules by melt compounding whereby no toxic solvent was used. The granular composite of GFLX-loaded PLGA and βTCP released GFLX for 42 days in Hanks' balanced solution and exhibited sufficient in vitro bactericidal activity against Streptococcus milleri and Bacteroides fragilis for at least 21 days. For in vivo evaluation, the granular composite was implanted in the dead space created by the debridement of osteomyelitis lesion induced by S. milleri and B. fragilis in rabbit mandible. After a 4-week implantation, the inflammation area within the debrided area was markedly reduced accompanied with osteoconduction and vascularization in half of the rabbits, and even disappeared in one of the six rabbits without any systemic administration of antibiotics. Outside the debrided area, inflammation and sequestrum were observed but the largest of such affected areas amounted to only 0.125 times of the originally infected and debrided area. These findings showed that the granular composite was effective for the local treatment of osteomyelitis as well as an osteoconductive scaffold which supported and encouraged vascularization.
Yang, Yang; Xie, Xiang Yang; Mei, Xing Guo
Poly (d,l-lactic-co-glycolide) nanoparticles (PLGA-NPs) have attracted considerable interest as new delivery vehicles for small molecules, with the potential to overcome issue such as poor drug solubility and cell permeability. However, their negative surface charge decreases bioavailability under oral administration. Recently, cationically modified PLGA-NPs has been introduced as novel carriers for oral delivery. In this study, our aim was to introduce and evaluate the physiochemical characteristics and bioadhesion of positively charged chitosan-coated PLGA-NPs (CS-PLGA-NPs), using thienorphine as a model drug. These results indicated that both CS-PLGA-NPs and PLGA-NPs had a narrow size distribution, averaging less than 130 nm. CS-PLGA-NPs was positively charged (+42.1 ± 0.4 mV), exhibiting the cationic nature of chitosan, whereas PLGA-NPs showed a negative surface charge (-2.01 ± 0.3 mV). CS-PLGA-NPs exhibited stronger bioadhesive potency than PLGA-NPs. Furthermore, the transport of thienorphine-CS-PLGA-NPs by Caco-2 cells was higher than thienorphine-PLGA-NPs or thienorphine solution. CS-PLGA-NPs were also found to significantly enhance cellular uptake compared with PLGA-NPs on Caco-2 cells. An evaluation of cytotoxicity showed no increase in toxicity in either kind of nanoparticles during the formulation process. The study proves that CS-PLGA-NPs can be used as a vector in oral drug delivery systems for thienorphine due to its positive surface charge and bioadhesive properties.
Background and the aim of the study The objective of the present study was to formulate and optimize nanoparticles (NPs) of sildenafil-loaded poly (lactic-co-glycolic acid) (PLGA) by double emulsion solvent evaporation (DESE) method. The relationship between design factors and experimental data was evaluated using response surface methodology. Method A Box-Behnken design was made considering the mass ratio of drug to polymer (D/P), the volumetric proportion of the water to oil phase (W/O) and the concentration of polyvinyl alcohol (PVA) as the independent agents. PLGA-NPs were successfully prepared and the size (nm), entrapment efficiency (EE), drug loading (DL) and cumulative release of drug from NPs post 1 and 8 hrs were assessed as the responses. Results The NPs were prepared in a spherical shape and the sizes range of 240 to 316 nm. The polydispersity index of size was lower than 0.5 and the EE (%) and DL (%) varied between 14-62% and 2-6%, respectively. The optimized formulation with a desirability factor of 0.9 was selected and characterized. This formulation demonstrated the particle size of 270 nm, EE of 55%, DL of 3.9% and cumulative drug release of 79% after 12 hrs. In vitro release studies showed a burst release at the initial stage followed by a sustained release of sildenafil from NPs up to 12 hrs. The release kinetic of the optimized formulation was fitted to Higuchi model. Conclusions Sildenafil citrate NPs with small particle size, lipophilic feature, high entrapment efficiency and good loading capacity is produced by this method. Characterization of optimum formulation, provided by an evaluation of experimental data, showed no significant difference between calculated and measured data. PMID:24355133
Chen, Hongbo; Zheng, Yi; Tian, Ge; Tian, Yan; Zeng, Xiaowei; Liu, Gan; Liu, Kexin; Li, Lei; Li, Zhen; Mei, Lin; Huang, Laiqiang
Three types of nanoparticle formulation from biodegradable PLGA-TPGS random copolymer were developed in this research for oral administration of anticancer drugs, which include DMAB-modified PLGA nanoparticles, unmodified PLGA-TPGS nanoparticles and DMAB-modified PLGA-TPGS nanoparticles. Firstly, the PLGA-TPGS random copolymer was synthesized and characterized. DMAB was used to increase retention time at the cell surface, thus increasing the chances of particle uptake and improving oral drug bioavailability. Nanoparticles were found to be of spherical shape with an average particle diameter of around 250 nm. The surface charge of PLGA-TPGS nanoparticles was changed to positive after DMAB modification. The results also showed that the DMAB-modified PLGA-TPGS nanoparticles have significantly higher level of the cellular uptake than that of DMAB-modified PLGA nanoparticles and unmodified PLGA-TPGS nanoparticles. In vitro, cytotoxicity experiment showed advantages of the DMAB-modified PLGA-TPGS nanoparticle formulation over commercial Taxotere® in terms of cytotoxicity against MCF-7 cells. In conclusion, oral chemotherapy by DMAB-modified PLGA-TPGS nanoparticle formulation is an attractive and promising treatment option for patients.
Najlah, Mohammad; Ahmed, Zahima; Iqbal, Mohammed; Wang, Zhipeng; Tawari, Patrica; Wang, Weiguang; McConville, Christopher
Non-Small Cell Lung Cancer (NSCLC) is the most common type of lung cancer in both men and women. A recent phase IIb study demonstrated that disulfiram (DSF) in combination with cisplatin and vinorelbine was well tolerated and prolonged the survival of patients with newly diagnosed NSCLC. However, DSF is rapidly (4min) metabolised in the bloodstream and it is this issue which is limiting its anticancer application in the clinic. We have recently demonstrated that a low dose of DSF-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles supplemented with oral Cu inhibited tumour growth and reduced metastasis in a xenograft mouse lung cancer model. Here we demonstrate the influence of PLGA polymer, stabilizer loading and molecular weight as well as sonication time on the characteristics, including DSF release and the cytotoxicity of 10% w/w DSF-loaded PLGA nanoparticles. The paper demonstrates that the choice of PLGA as no significance on the characteristics of the nanoparticles apart from their DSF release, which is due to the differing degradation rates of the polymers. However, increasing the loading and molecular weight of the stabilizer as well as the sonication time reduced the size of the nanoparticles, reduced their ability to protect the DSF from reacting with Cu and degrading in serum, while increasing their DSF release rate and cytotoxicity. Additionally, increasing the sonication time resulted in the premature degradation of the PLGA, which increased the permeability of the nanoparticles further decreasing their ability to protect DSF from reacting with Cu and degrading in serum, while increasing their DSF release rate and cytotoxicity. Copyright © 2016 Elsevier B.V. All rights reserved.
Wu, Binquan; Liang, Yong; Tan, Yi; Xie, Chunmei; Shen, Jin; Zhang, Mei; Liu, Xinkuang; Yang, Lixin; Zhang, Fujian; Liu, Liang; Cai, Shuyu; Huai, De; Zheng, Donghui; Zhang, Rongbo; Zhang, Chao; Chen, Ke; Tang, Xiaolong; Sui, Xuemei
The purpose of this research is to develop nanoparticles (NPs) of star-shaped copolymer mannitol-functionalized PLGA-TPGS for Genistein delivery for liver cancer treatment, and evaluate their therapeutic effects in liver cancer cell line and hepatoma-tumor-bearing nude mice in comparison with the linear PLGA nanoparticles and PLGA-TPGS nanoparticles. The Genistein-loaded M-PLGA-TPGS nanoparticles (MPTN), prepared by a modified nanoprecipitation method, were observed by FESEM and TEM to be near-spherical shape with narrow size distribution. The nanoparticles were further characterized in terms of their size, size distribution, surface charge, drug-loading content, encapsulation efficiency and in vitro drug release profiles. The data showed that the M-PLGA-TPGS nanoparticles were found to be stable, showing almost no change in particle size and surface charge during 3-month storage of their aqueous solution. In vitro Genistein release from the nanoparticles exhibited biphasic pattern with burst release at the initial 4days and sustained release afterwards. The cellular uptake efficiency of fluorescent M-PLGA-TPGS nanoparticles was 1.25-, 1.22-, and 1.29-fold higher than that of the PLGA-TPGS nanoparticles at the nanoparticle concentrations of 100, 250, and 500μg/mL, respectively. In the MPTN group, the ratio of apoptotic cells increased with the drug dose increased, which exhibited dose-dependent effect and a significant difference compared with Genistein solution group (p<0.05). The data also showed that the Genistein-loaded M-PLGA-TPGS nanoparticles have higher antitumor efficacy than that of linear PLGA-TPGS nanoparticles and PLGA nanoparticles in vitro and in vivo. In conclusion, the star-shaped copolymer M-PLGA-TPGS could be used as a potential and promising bioactive material for nanomedicine development for liver cancer treatment.
Sun, Dongdong; Li, Nuan; Zhang, Weiwei; Yang, Endong; Mou, Zhipeng; Zhao, Zhiwei; Liu, Haiping; Wang, Weiyun
Nanotechnology-based approaches have tremendous potential for enhancing efficacy against infectious diseases. PLGA-based nanoparticles as drug delivery carrier have shown promising potential, owing to their sizes and related unique properties. This article aims to develop nanosized poly ( d, l-lactide-co-glycolide) PLGA nanoparticle formulation loaded with quercetin (QT). QT is an antioxidant and antibacterial compound isolated from Chinese traditional medicine with low skin permeability and extreme water insolubility. The quercetin-loaded PLGA nanoparticles (PQTs) were synthesized by emulsion-solvent evaporation method and stabilized by coating with poly (vinyl alcohol). The characteristics of PQTs were analyzed by Fourier transform infrared spectroscopy, Ultraviolet-Visible spectroscopy, scanning electron microscope, transmission electron microscopy, and atomic force microscopy, respectively. The PQTs showed a spherical shape with an average size of 100-150 nm. We compared the antibacterial effects of PQTs against Escherichia coli ( E. coli) and Micrococcus tetragenus ( M. tetragenus).The PQTs produced stronger antibacterial activity to E. coli than that to M. tetragenus through disrupting bacterial cell wall integrity. The antibacterial ratio was increased with the increasing dosages and incubation time. Next, we tested the in vivo antibacterial activity in mice. No noticeable organ damage was captured from H&E-staining organ slices, suggesting the promise of using PQTs for in vivo applications. The results of this study demonstrated the interaction between bacteria and PLGA-based nanoparticles, providing encouragement for conducting further investigations on properties and antimicrobial activity of the PQTs in clinical application.
Hazekawa, Mai; Morihata, Kana; Yoshida, Miyako; Sakai, Yoshiki; Uchida, Takahiro
The purpose of this study was to evaluate the angiogenic effect of topical application of three types of ONO-1301-loaded poly (lactide-co-glycolide) microspheres (ONO-1301 PLGA MS). ONO-1301 PLGA MS were prepared with PLGA 5010, 5020 and 5050 (with molecular weights of 10 K, 20 K and 50 K, respectively), using the solvent evaporation method. The lactide:glycolide ratio was fixed at 50:50; only the molecular weight was varied. The microspheres had an average diameter of almost 25 µm, and a loading efficiency of at least 70%. The sustained-release effect and its dependence on the molecular weight of the polymer used was confirmed in an in vitro drug-release test and by measuring subcutaneous plasma levels after administration of the three types of ONO-1301 PLGA MS to rats for 28 days. In the murine sponge model, the three types of ONO-1301 PLGA MS were administered to mice in a subcutaneously placed sponge and hemoglobin and hepatocyte growth factor (HGF) levels in the sponge were measured at predefined intervals up to 28 days. The hemoglobin and HGF levels obtained were significantly higher than those obtained after daily administration of ONO-1301 powder. Additional in vivo fluorescence imaging showed that PLGA MS remained in the sponge for 28 days. In conclusion, the three types of ONO-1301 PLGA MS prepared with PLGA three different molecular weight suppress the burst release, stimulate angiogenesis on topical application in a murine sponge model. This formulation may therefore be capable of improving the clinical picture in some types of vascular disease.
Guan, Qingxia; Sun, Shuang; Li, Xiuyan; Lv, Shaowa; Xu, Ting; Sun, Jialin; Feng, Wenjing; Zhang, Liang; Li, Yongji
This study investigated the therapeutic efficiency of monomethoxy polyethylene glycol-poly(lactic-co-glycolic acid) (mPEG-PLGA) co-loaded with syringopicroside and hydroxytyrosol as a drug with effective targeting and loading capacity as well as persistent circulation in vivo. The nanoparticles were prepared using a nanoprecipitation method with mPEG-PLGA as nano-carrier co-loaded with syringopicroside and hydroxytyrosol (SH-NPs). The parameters like in vivo pharmacokinetics, biodistribution in vivo, fluorescence in vivo endomicroscopy, and cellular uptake of SH-NPs were investigated. Results showed that the total encapsulation efficiency was 32.38 ± 2.76 %. Total drug loading was 12.01 ± 0.42 %, particle size was 91.70 ± 2.11 nm, polydispersity index was 0.22 ± 0.01, and zeta potential was -24.5 ± 1.16 mV for the optimized SH-NPs. The nanoparticle morphology was characterized using transmission electron microscopy, which indicated that the particles of SH-NPs were in uniformity within the nanosize range and of spherical core shell morphology. Drug release followed Higuchi kinetics. Compared with syringopicroside and hydroxytyrosol mixture (SH), SH-NPs produced drug concentrations that persisted for a significantly longer time in plasma following second-order kinetics. The nanoparticles moved gradually into the cell, thereby increasing the quantity. ALT, AST, and MDA levels were significantly lower on exposure to SH-NPs than in controls. SH-NPs could inhibit the proliferation of HepG2.2.15 cells and could be taken up by HepG2.2.15 cells. The results confirmed that syringopicroside and hydroxytyrosol can be loaded simultaneously into mPEG-PLGA nanoparticles. Using mPEG-PLGA as nano-carrier, sustained release, high distribution in the liver, and protective effects against hepatic injury were observed in comparison to SH.
Fornaguera, C; Feiner-Gracia, N; Calderó, G; García-Celma, M J; Solans, C
The interest in polymeric nanoparticles as imaging systems for biomedical applications has increased notably in the last decades. In this work, PLGA nanoparticles, prepared from nano-emulsion templating, have been used to prepare novel fluorescent imaging agents. Two model fluorescent dyes were chosen and dissolved in the oil phase of the nano-emulsions together with PLGA. Nano-emulsions were prepared by the phase inversion composition (PIC) low-energy method. Fluorescent dye-loaded nanoparticles were obtained by solvent evaporation of nano-emulsion templates. PLGA nanoparticles loaded with the fluorescent dyes showed hydrodynamic radii lower than 40nm; markedly lower than those reported in previous studies. The small nanoparticle size was attributed to the nano-emulsification strategy used. PLGA nanoparticles showed negative surface charge and enough stability to be used for biomedical imaging purposes. Encapsulation efficiencies were higher than 99%, which was also attributed to the nano-emulsification approach as well as to the low solubility of the dyes in the aqueous component. Release kinetics of both fluorescent dyes from the nanoparticle dispersions was pH-independent and sustained. These results indicate that the dyes could remain encapsulated enough time to reach any organ and that the decrease of the pH produced during cell internalization by the endocytic route would not affect their release. Therefore, it can be assumed that these nanoparticles are appropriate as systemic imaging agents. In addition, in vitro toxicity tests showed that nanoparticles are non-cytotoxic. Consequently, it can be concluded that the preparation of PLGA nanoparticles from nano-emulsion templating represents a very versatile technology that enables obtaining biocompatible, biodegradable and safe imaging agents suitable for biomedical purposes.
Zhang, Fan; Song, Qingxin; Huang, Xuan; Li, Fengning; Wang, Kun; Tang, Yixing; Hou, Canglong; Shen, Hongxing
A potential bone tissue engineering material was produced from a biodegradable polymer, poly(lactic-co-glycolic acid) (PLGA), loaded with nanodiamond phospholipid compound (NDPC) via physical mixing. On the basis of hydrophobic effects and physical absorption, we modified the original hydrophilic surface of the nanodiamond (NDs) with phospholipids to be amphipathic, forming a typical core-shell structure. The ND-phospholipid weight ratio was optimized to generate sample NDPC50 (i.e., ND-phospholipid weight ratio of 100:50), and NDPC50 was able to be dispersed in a PLGA matrix at up to 20 wt %. Compared to a pure PLGA matrix, the introduction of 10 wt % of NDPC (i.e., sample NDPC50-PF10) resulted in a significant improvement in the material's mechanical and surface properties, including a decrease in the water contact angle from 80 to 55°, an approximately 100% increase in the Young's modulus, and an approximate 550% increase in hardness, thus closely resembling that of human cortical bone. As a novel matrix supporting human osteoblast (hFOB1.19) growth, NDPC50-PFs with different amounts of NDPC50 demonstrated no negative effects on cell proliferation and osteogenic differentiation. Furthermore, we focused on the behaviors of NDPC-PFs implanted into mice for 8 weeks and found that NDPC-PFs induced acceptable immune response and can reduce the rapid biodegradation of PLGA matrix. Our results represent the first in vivo research on ND (or NDPC) as nanofillers in a polymer matrix for bone tissue engineering. The high mechanical properties, good in vitro and in vivo biocompatibility, and increased mineralization capability suggest that biodegradable PLGA composite matrices loaded with NDPC may potentially be useful for a variety of biomedical applications, especially bone tissue engineering.
Chereddy, Kiran Kumar; Her, Charles-Henry; Comune, Michela; Moia, Claudia; Lopes, Alessandra; Porporato, Paolo E; Vanacker, Julie; Lam, Martin C; Steinstraesser, Lars; Sonveaux, Pierre; Zhu, Huijun; Ferreira, Lino S; Vandermeulen, Gaëlle; Préat, Véronique
Wound treatment remains one of the most prevalent and economically burdensome healthcare issues in the world. Poly (lactic-co-glycolic acid) (PLGA) supplies lactate that accelerates neovascularization and promotes wound healing. LL37 is an endogenous human host defense peptide that modulates wound healing and angiogenesis and fights infection. Hence, we hypothesized that the administration of LL37 encapsulated in PLGA nanoparticles (PLGA-LL37 NP) promotes wound closure due to the sustained release of both LL37 and lactate. In full thickness excisional wounds, the treatment with PLGA-LL37 NP significantly accelerated wound healing compared to PLGA or LL37 administration alone. PLGA-LL37 NP-treated wounds displayed advanced granulation tissue formation by significant higher collagen deposition, re-epithelialized and neovascularized composition. PLGA-LL37 NP improved angiogenesis, significantly up-regulated IL-6 and VEGFa expression, and modulated the inflammatory wound response. In vitro, PLGA-LL37 NP induced enhanced cell migration but had no effect on the metabolism and proliferation of keratinocytes. It displayed antimicrobial activity on Escherichia coli. In conclusion, we developed a biodegradable drug delivery system that accelerated healing processes due to the combined effects of lactate and LL37 released from the nanoparticles.
Bhargava-Shah, Aarohi; Foygel, Kira; Devulapally, Rammohan; Paulmurugan, Ramasamy
Background: This study explores the use of hydrophilic poly(ethylene glycol)-conjugated poly(lactic-co-glycolic acid) nanoparticles (PLGA-PEG-NPs) as delivery system to improve the antitumor effect of antiobesity drug orlistat for triple-negative breast cancer (TNBC) therapy by improving its bioavailability. Materials & methods: PLGA-PEG-NPs were synthesized by emulsion-diffusion-evaporation method, and the experiments were conducted in vitro in MDA-MB-231 and SKBr3 TNBC and normal breast fibroblast cells. Results: Delivery of orlistat via PLGA-PEG-NPs reduced its IC50 compared with free orlistat. Combined treatment of orlistat-loaded NPs and doxorubicin or antisense-miR-21-loaded NPs significantly enhanced apoptotic effect compared with independent doxorubicin, anti-miR-21-loaded NPs, orlistat-loaded NPs or free orlistat treatments. Conclusion: We demonstrate that orlistat in combination with antisense-miR-21 or current chemotherapy holds great promise as a novel and versatile treatment agent for TNBC. PMID:26787319
Song, Jia; Fan, Xiucong; Shen, Qi
Daidzein is one of the most effective candidates for treating cardiovascular and cerebrovascular disease. However, considering its poor oral absorption and limited bioavailability, daidzein-loaded nanostructured lipid carriers-PLGA nanofibers were designed to handle the drawbacks. Daidzein-NLCs were successfully prepared by an emulsification and low-temperature solidification method. The physicochemical characteristics of NLCs were evaluated afterwards. Based on the preparation of daidzein-loaded NLCs, Daidzein-NLCs-nanofibers were optimized by electrospinning and were observed under Scanning Electron Microscope to capture the appearance. The sustained release profile of daidzein from Daidzein-NLCs-nanofibers in vivo was best fitted to the Kormeyer-Peppas equation. The in vitro skin permeable behavior showed the cumulative amount of daidzein from Daidzein-NLCs-nanofibers reached 21.71 μg cm(-2) at 60 h, which was 3.78 times higher than pure daidzein solution. It demonstrated that the Daidzein-NLCs-nanofibers could significantly enhance the transported amount of drug. Confocal Laser Scanning Microscopy resulting images revealed a more effective content accumulation of Daidzein-NLCs-nanofibers than Daidzein-NLCs in epidermis. In vivo study indicated that Daidzein-NLCs-nanofibers had better skin retention than Daidzein-NLCs in the long term. The skin irritation experiment showed a positive result with no obvious stimulus observed. These results suggested that Daidzein-NLCs-nanofibers could be a potential candidate for transdermal delivery. Copyright © 2016 Elsevier B.V. All rights reserved.
Ruggiero, Maria R.; Geninatti Crich, Simonetta; Sieni, Elisabetta; Sgarbossa, Paolo; Forzan, Michele; Cavallari, Eleonora; Stefania, Rachele; Dughiero, Fabrizio; Aime, Silvio
Magnetic iron oxide nanoparticles (Fe-NPs) can be exploited in biomedicine as agents for magnetic fluid hyperthermia (MFH) treatments and as contrast enhancers in magnetic resonance imaging. New, oleate-covered, iron oxide particles have been prepared either by co-precipitation or thermal decomposition methods and incorporated into poly(lactic-co-glycolic acid) nanoparticles (PLGA-Fe-NPs) to improve their biocompatibility and in vivo stability. Moreover, the PLGA-Fe-NPs have been loaded with paclitaxel to pursue an MFH-triggered drug release. Remarkably, it has been found that the nanoparticle formulations are characterized by peculiar 1H nuclear magnetic relaxation dispersion (NMRD) profiles that directly correlate with their heating potential when exposed to an alternating magnetic field. By prolonging the magnetic field exposure to 30 min, a significant drug release was observed for PLGA-Fe-NPs in the case of the larger-sized magnetic nanoparticles. Furthermore, the immobilization of lipophilic Fe-NPs in PLGA-NPs also made it possible to maintain Néel relaxation as the dominant relaxation contribution in the presence of large iron oxide cores (diameters of 15-20 nm), with the advantage of preserving their efficiency when they are entrapped in the intracellular environment. The results reported herein show that NMRD profiles are a useful tool for anticipating the heating capabilities of Fe-NPs designed for MFH applications.
Cannavà, Carmela; Tommasini, Silvana; Stancanelli, Rosanna; Cardile, Venera; Cilurzo, Felisa; Giannone, Ignazio; Puglisi, Giovanni; Ventura, Cinzia Anna
PLGA microspheres were prepared as a sustained release system for the intra-articular administration of celecoxib (CCB). The microspheres were prepared in the presence of different concentrations of dimethyl-β-cyclodextrin (DM-β-Cyd), by the simple oil-in-water emulsion/evaporation solvent method. The microspheres were evaluated as to surface morphology, size and technological properties (such as encapsulation efficiency, drug loading capacity and drug release). Ex vivo studies on cultures of human chondrocytes were performed in order to evaluate the influence of the polymeric carriers on the pharmacological activity of CCB. All systems ranged from about 1 to 5 μm in size and had a high encapsulation efficiency percentage ranging from about 80% to 90% (w/w), except for CCB-loaded-PLGA microspheres containing the highest amount of DM-β-Cyd, in which a dramatic drop in the encapsulation efficiency was observed (about 54%, w/w). FIB images evidenced the fact that the microspheres had a porous structure in the presence of the highest amount of DM-β-Cyd. The macrocycle modulated the release profiles of CCB from the microspheres, producing in some cases a zero-order kinetic release. Ex vivo biological studies demonstrated that DM-β-Cyd improved the drug's anti-inflammatory activity. Thus, CCB-loaded PLGA/cyclodextrin microspheres may have a potential therapeutic application in the treatment of osteo- and rheumatoid arthritis. Copyright © 2013 Elsevier B.V. All rights reserved.
Song, Wantong; Tang, Zhaohui; Lei, Tian; Wen, Xue; Wang, Guanyi; Zhang, Dawei; Deng, Mingxiao; Tang, Xing; Chen, Xuesi
Disulfiram (DSF) showed great potential in an in vitro tumor therapy study; however, those results could not be applied to an in vivo study due to the extreme instability of DSF in blood. Here, we describe a system of methoxy poly(ethylene glycol)-b-poly(lactide-co-glycolide)/poly(ε-caprolactone) (mPEG-PLGA/PCL) mixed nanoparticles (NPs) for DSF loading and delivery. By adjusting the mPEG-PLGA/PCL content ratios, the DSF loading capacity increased to 7.8%, while the hydrodynamic radii of the NPs were around 50-100nm. The DSF-loaded NPs showed high stability in distilled water and 10% serum-containing phosphate buffered saline. The NPs efficiently protected DSF from degradation while maintaining its anti-tumor properties. Furthermore, a pharmacokinetics study demonstrated that NP delivery system enhanced the DSF concentration in the blood after tail vein injection. Finally, DSF delivery using this model effectively slowed the growth of a 4T1 murine xenograft tumor. The anti-tumor efficacy of the anti-alcoholic drug disulfiram has been known for some time. However, its use in the clinical setting is limited due to the underlying instability of the drug. In this study, the authors utilized a nanocarrier system of mPEG-PLGA/PCL for the delivery of this drug. The promising results may allow encapsulation of other drugs. Copyright © 2015. Published by Elsevier Inc.
Song, Xiang Rong; Zheng, Yu; He, Gu; Yang, Li; Luo, You Fu; He, Zhi Yao; Li, Shuang Zhi; Li, Jun Ming; Yu, Shui; Luo, Xun; Hou, Shi Xiang; Wei, Yu Quan
Hepatocellular carcinoma (HCC) is one of the malignant tumors with poor chemo-sensitivity to vincristine sulfate (VCR) due to multi-drug resistance (MDR). Combinations of encapsulated VCR and verapamil hydrochloride (VRP, a chemo-sensitizer) might be a potential strategy to improve HCC therapeutic efficacy of VCR. PLGA nanoparticles (PLGANPs) simultaneously loaded with VCR and VRP (CVn) were prepared. The entrapment efficiencies of VCR and VRP were 70.92 ± 3.78% and 85.78 ± 3.23%, respectively (n = 3). The HCC therapeutic activity of CVn was assessed using MTT assay. In BEL7402 and BEL7402/5-FU human hepatocarcinoma cell lines, CVn had the same antitumor effect as one free drug/another agent-loaded PLGANPs (C + Vn or Cn + V) combination and coadministration of two single-agent-loaded PLGANPs (Cn + Vn), which was slightly higher than that of the free VCR/VRP combination (C - V). CVn might cause lower normal tissue drug toxicity by the enhanced permeation and retention effect in vivo. Additionally, CVn might cause fewer drug-drug interaction and be the most potential formulation to simultaneously deliver VCR and VRP to the target cell in vivo than the other three nanoparticle formulations (C + Vn, Cn + V, and Cn + Vn). Therefore, we speculate that CVn might be the most effective preparation in the treatment of drug-resistant human HCC in vivo. © 2010 Wiley-Liss, Inc. and the American Pharmacists Association
Sharma, Deepak; Sharma, Rakesh Kumar; Bhatnagar, Aseem; Nishad, Dhruv K; Singh, Thakuri; Gabrani, Reema; Sharma, Sanjeev K; Ali, Javed; Dang, Shweta
The present study is aimed to develop poly(D, L-lactide-co-glycolic acid) (PLGA) nanoparticles (NP) loaded with midazolam (Mdz) for nose to brain delivery. NP were formulated by nanoprecipitation and characterized for z-average, zeta potential, % drug entrapment and ex vivo drug release. Mdz NP (MNP) were radiolabeled with technetium-99m. Biodistribution and gamma scintigraphic studies were performed on Sprague-Dawley rats following intranasal (i.n) and intravenous (i.v) administration to trace the transport of Mdz for nose-to-brain delivery. MNP showed z-average of 164±4.5nm with polydispersity index 0.099±0.02 and zeta potential of -16.6±2.5mV. Ex vivo drug studies indicated that MNP showed 29±1.2% of permeation upto 4h via sheep nasal mucosa, whereas Mdz suspension (MS) showed drug release of 83±1.2% within 4h. Comparing i.n administration of MNP, MS and i.v administration of MS, scintigraphy imaging and Brain/blood uptake ratios indicated higher brain targeting via i.n administration of MNP. Results indicated that the i.n MNP could be employed as a non invasive mode of delivery system with improved drug entrapment, stability and controlled drug release over a period of time.
Zhang, Hao-Xuan; Zhang, Xiu-Ping; Xiao, Gui-Yong; Hou, Yong; Cheng, Lei; Si, Meng; Wang, Shuai-Shuai; Li, Yu-Hua; Nie, Lin
Avascular necrosis of the femoral head (ANFH) is difficult to treat due to high pressure and hypoxia, and reduced levels of growth factors such as bone morphogenetic protein (BMP), and vascular endothelial growth factor (VEGF). We generated a novel calcium phosphate (CPC) composite scaffold, which contains BMP-VEGF-loaded poly-lactic-co-glycolic acid (PLGA) microspheres (BMP-VEGF-PLGA-CPC). The BMP-VEGF-loaded microspheres have an encapsulation efficiency of 89.15% for BMP, and 78.55% for VEGF. The BMP-VEGF-PLGA-CPC scaffold also demonstrated a porosity of 62% with interconnected porous structures, and pore sizes of 219 μm and compressive strength of 6.60 MPa. Additionally, bone marrow mesenchymal stem cells (BMSCs) were seeded on scaffolds in vitro. Further characterization showed that the BMP-VEGF-PLGA-CPC scaffolds were biocompatible and enhanced osteogenesis and angiogenesis in vitro. Using a rabbit model of ANFH, BMP-VEGF-PLGA-CPC scaffolds were implanted into the bone tunnels of core decompression in the femoral head for 6 and 12 weeks. Radiographic and histological analysis demonstrated that the BMP-VEGF-PLGA-CPC scaffolds exhibited good biocompatibility, and osteogenic and angiogenic activity in vivo. These results indicate that the BMP-VEGF-PLGA-CPC scaffold may improve the therapeutic effect of core decompression surgery and be used as a treatment for ANFH.
McConville, Christopher; Tawari, Patricia; Wang, Weiguang
Glioblastoma multiforme (GBM) has a poor prognosis and is one of the most common primary malignant brain tumours in adults. Stereotactic injections have been used to deliver chemotherapeutic drugs directly into brain tumours. This paper describes the development of disulfiram (DSF)-loaded biodegradable millirods manufactured using hot melt extrusion (HME) and injection moulding (IM). The paper demonstrates that the stability of the DSF within the millirods is dependent on the manufacturing technique used as well as the drug loading. The physical state of the DSF within the millirods was dependent on the fabrication process, with the DSF in the HME millirods being either completely amorphous within the PLGA, while the DSF within the IM millirods retained between 54 and 66% of its crystallinity. Release of DSF from the millirods was dependent on the degradation rate of the PLGA, the manufacturing technique used as well as the DSF loading. DSF in the 10% (w/w) DSF loaded HME millirods and the 20% (w/w) DSF-loaded HME and IM millirods had a similar cytotoxicity against a GBM cell line compared to the unprocessed DSF control. However, the 10% (w/w) DSF-loaded IM millirods had a significantly lower cytotoxicity when compared to the unprocessed control. Copyright © 2015 Elsevier B.V. All rights reserved.
Kumar, Gaurav; Sharma, Sadhna; Shafiq, Nusrat; Khuller, Gopal Krishan; Malhotra, Samir
A novel poly(lactic-co-glycolic acid) (PLGA)-based nanoformulation of levofloxacin was developed for multidrug-resistant tuberculosis with the purpose of achieving sustained release in plasma. After lyophilization of levofloxacin-loaded nanoparticles, the average size, charge, and polydispersity index were 268 ± 18 nm, -10.2 ± 1.5 mV, and 0.15 ± 0.03, respectively. The maximum drug encapsulation efficiency and loading capacity were 36.9 ± 6.1% (w/w) and 7.2 ± 1.2 mg/100 mg nanopowder, respectively. Biphasic extended-release profile was produced in vitro. Scanning electron microscopy and Fourier transform infrared studies showed spherical shape of drug-loaded nanoparticles and no drug-polymer interactions were observed. After single oral administration in mice, levofloxacin-loaded PLGA nanoparticles produced sustained release of levofloxacin for 4 days in plasma against 24 h for free levofloxacin. Levofloxacin was detected in organs (lung, liver, and spleen) for up to 4-6 days in case of levofloxacin-loaded nanoparticles, whereas free levofloxacin was cleared within 24 h. This novel formulation did not show any significant adverse effects on body weight and clinical signs in mice. No treatment-related changes were found in hematological and biochemical parameters and on histopathological evaluation. These results indicate the feasibility of development of an orally efficacious safe formulation of levofloxacin with sustained-release properties.
Parumasivam, Thaigarajan; Leung, Sharon S Y; Quan, Diana Huynh; Triccas, Jamie A; Britton, Warwick J; Chan, Hak-Kim
Inhaled delivery of drugs incorporated into poly (lactic-co-glycolic acid) (PLGA) microparticles allows a sustained lung concentration and encourages phagocytosis by alveolar macrophages that harboring Mycobacterium tuberculosis. However, limited data are available on the effects of physicochemical properties of PLGA, including the monomer ratio (lactide:glycide) and molecular weight (MW) on the aerosol performance, macrophage uptake, and toxicity profile. The present study aims to address this knowledge gap, using PLGAs with monomer ratios of 50:50, 75:25 and 85:15, MW ranged 24 - 240kDa and an anti-tuberculosis (TB) drug, rifapentine. The PLGA-rifapentine powders were produced through a solution spray drying technique. The particles were spherical with a smooth surface and a volume median diameter around 2μm (span ~2). When the powders were dispersed using an Osmohaler(®) at 100L/min for 2.4s, the fine particle fraction (FPFtotal, wt.% particles in aerosol <5μm relative to the total recovered drug mass) was ranged between 52 and 57%, with no significant difference between the formulations. This result suggests that the monomer ratio and MW are not crucial parameters for the aerosol performance of PLGA. The phagocytosis analysis was performed using Thp-1 monocyte-derived macrophages. The highest rate of uptake was observed in PLGA 85:15 followed by 75:25 and 50:50 with about 90%, 80% and 70%, respectively phagocytosis over 4h of exposure. Furthermore, the cytotoxicity analysis on Thp-1 and human lung adenocarcinoma epithelial cells demonstrated that PLGA concentration up to 1.5mg/mL, regardless of the monomer composition and MW, were non-toxic. In conclusion, the monomer ratio and MW are not crucial in determining the aerosol performance and cytotoxicity profile of PLGA however, the particles with high lactide composition have a superior tendency for macrophage uptake.
Wan, Feng; Maltesen, Morten Jonas; Andersen, Sune Klint; Bjerregaard, Simon; Foged, Camilla; Rantanen, Jukka; Yang, Mingshi
The aim of this study was to investigate the potential of using a spray-dryer equipped with a 3-fluid nozzle to microencapsulate protein drugs into polymeric microparticles. Lysozyme and PLGA were used as a model protein and a model polymer, respectively. The effects of process and formulation variables, such as i) the type of organic solvent, ii) the feeding rate ratio of the outer PLGA-containing feed solution to inner lysozyme-containing feed solution, and iii) the mass ratio of PLGA to protein, on the properties (morphology, internal structure, protein surface enrichment and release profiles) of the spray dried microparticles were investigated to understand protein microencapsulation and particle formation mechanisms. The spherical, condensed microparticles were obtained with D50 of 1.07-1.60 μm and Span in the range of 0.82-1.23. The lysozyme surface content decreased upon different organic solvents used as follows: acetonitrile > acetone > dichloromethane. Additionally, the lysozyme surface enrichment decreased slightly when increasing the feeding rate ratio of the outer feed solution to the inner feed solution from 4:1 to 10:1. Furthermore, it was observed that there was a correlation between the degree of burst release and the lysozyme surface enrichment, whereas the lysozyme loading content had no substantial impact on the release kinetics. The present work demonstrates the potential of spray dryer equipped with a 3-fluid nozzle in microencapsulation of proteins into PLGA matrices with different characteristics by varying process and formulation parameters.
Gao, Shanshan; Zhao, Na; Amer, Said; Qian, Mingming; Lv, Mengxi; Zhao, Yuliang; Su, Xin; Cao, Jieying; He, Hongxuan; Zhao, Baohua
In the present study, poly (lactic-co-glycolic) acid (PLGA) was used as a carrier for a divalent fusion DNA vaccine encoding the Aeromonas veronii outer membrane protein A (ompA) and Aeromonas hydrophila hemolysins (hly) protein. The recombinant pET-28a-ompA-hly was constructed by inserting the ompA gene and hly gene into a pET-28a expression vector. Loading of ompA-hly antigen module on PLGA microspheres were accomplished by water-in-oil-in-water (W/O/W) encapsulation. The molecular weight and specificity of pET-28a-ompA-hly were detected by dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and western blotting. The microspheres showed an average particle size of 100-150 μm and a loading efficiency (LE) of 68.8%. Mice received ompA-hly antigen-loaded PLGA microspheres by intraperitoneal or intragastric administration mounted strong and sustained IgG response, which was significantly higher (p<0.05) than those achieved by pET-28a-ompA-hly antigen alone. OmpA-hly antigen-loaded PLGA microsphere vaccine uniquely conferred a long lasting (30 days) sterile immunity against challenge infection. Results indicated that ompA-hly antigen-loaded PLGA microsphere vaccine is a qualified candidate vector system for sterile protective immunity against A. hydrophila and A. veronii infections.
Hamzian, Nima; Hashemi, Maryam; Ghorbani, Mahdi; Bahreyni Toosi, Mohammad Hossein; Ramezani, Mohammad
The aim of this study was to develop a novel multifunctional nanoparticle, which encapsulates SPION and Gemcitabine in PLGA ± PEG to form multifunctional drug delivery system. For this aim, super paramagnetic iron oxide nanoparticles (SPIONs) were simultaneously synthesized and encapsulated with Gemcitabine (Gem) in PLGA ± PEG copolymers via W/O/W double emulsification method. Optimum size and encapsulation efficiency for radiosensitization, hyperthermia and diagnostic applications were considered and the preparation parameters systematically were investigated and physicochemical characteristics of optimized nanoparticle were studied. Then SPION-PLGA and PLGA-Gem nanoparticles were prepared with the same optimized parameters and the toxicity of these nanoparticles was compared with Gemcitabine in human breast cancer cell line (MCF-7). The optimum preparation parameters were obtained with Gem/polymer equal to 0.04, SPION/polymer equal to 0.8 and 1% sucrose per 20 mg of polymer. The hydrodynamic diameters of all nanoparticles were under 200 nm. Encapsulation efficiency was adjusted between 13.2% to 16.1% for Gemcitabine and 48.2% to 50.1% for SPION. In-vitro Gemcitabine release kinetics had controlled behavior. Enhancement ratios for PLGA-Gem and SPION-PLGA-Gem at concentration of nanoparticles equal to IC50 of Gemcitabine were 1.53 and 1.89 respectively. The statistical difference was significant (p-value = 0.006 for SPION-PLGA-Gem and p-value = 0.015 for PLGA-Gem compared with Gemcitabine). In conclusion, we have successfully developed a Gemcitabine loaded super paramagnetic PLGA-Iron Oxide multifunctional drag delivery system. Future work includes in-vitro and in-vivo investigation of radiosensitization and other application of these nanoparticles.
Situ, Jun-Qing; Wang, Xiao-Juan; Zhu, Xiu-Liang; Xu, Xiao-Ling; Kang, Xu-Qi; Hu, Jing-Bo; Lu, Chen-Ying; Ying, Xiao-Ying; Yu, Ri-Sheng; You, Jian; Du, Yong-Zhong
Specific delivery of chemotherapy drugs and magnetic resonance imaging (MRI) contrast agent into tumor cells is one of the issues to highly efficient tumor targeting therapy and magnetic resonance imaging. Here, A54 peptide-functionalized poly(lactic-co-glycolic acid)-grafted dextran (A54-Dex-PLGA) was synthesized. The synthesized A54-Dex-PLGA could self-assemble to form micelles with a low critical micelle concentration of 22.51 μg. mL-1 and diameter of about 50 nm. The synthetic A54-Dex-PLGA micelles can encapsulate doxorubicin (DOX) as a model anti-tumor drug and superparamagnetic iron oxide (SPIO) as a contrast agent for MRI. The drug-encapsulation efficiency was about 80% and the in vitro DOX release was prolonged to 72 hours. The DOX/SPIO-loaded micelles could specifically target BEL-7402 cell line. In vitro MRI results also proved the specific binding ability of A54-Dex-PLGA/DOX/SPIO micelles to hepatoma cell BEL-7402. The in vivo MR imaging experiments using a BEL-7402 orthotopic implantation model further validated the targeting effect of DOX/SPIO-loaded micelles. In vitro and in vivo anti-tumor activities results showed that A54-Dex-PLGA/DOX/SPIO micelles revealed better therapeutic effects compared with Dex-PLGA/DOX/SPIO micelles and reduced toxicity compared with commercial adriamycin injection.
Situ, Jun-Qing; Wang, Xiao-Juan; Zhu, Xiu-Liang; Xu, Xiao-Ling; Kang, Xu-Qi; Hu, Jing-Bo; Lu, Chen-Ying; Ying, Xiao-Ying; Yu, Ri-Sheng; You, Jian; Du, Yong-Zhong
Specific delivery of chemotherapy drugs and magnetic resonance imaging (MRI) contrast agent into tumor cells is one of the issues to highly efficient tumor targeting therapy and magnetic resonance imaging. Here, A54 peptide-functionalized poly(lactic-co-glycolic acid)-grafted dextran (A54-Dex-PLGA) was synthesized. The synthesized A54-Dex-PLGA could self-assemble to form micelles with a low critical micelle concentration of 22.51 μg. mL−1 and diameter of about 50 nm. The synthetic A54-Dex-PLGA micelles can encapsulate doxorubicin (DOX) as a model anti-tumor drug and superparamagnetic iron oxide (SPIO) as a contrast agent for MRI. The drug-encapsulation efficiency was about 80% and the in vitro DOX release was prolonged to 72 hours. The DOX/SPIO-loaded micelles could specifically target BEL-7402 cell line. In vitro MRI results also proved the specific binding ability of A54-Dex-PLGA/DOX/SPIO micelles to hepatoma cell BEL-7402. The in vivo MR imaging experiments using a BEL-7402 orthotopic implantation model further validated the targeting effect of DOX/SPIO-loaded micelles. In vitro and in vivo anti-tumor activities results showed that A54-Dex-PLGA/DOX/SPIO micelles revealed better therapeutic effects compared with Dex-PLGA/DOX/SPIO micelles and reduced toxicity compared with commercial adriamycin injection. PMID:27775017
Liu, Xu-Jie; Li, Liang; Liu, Xiu-Jun; Li, Yi; Zhao, Chun-Yan; Wang, Rui-Qi; Zhen, Yong-Su
Previous studies have shown that mithramycin A (MIT) is a promising candidate for the treatment of pancreatic carcinoma through inhibiting transcription factor Sp1. However, systemic toxicities may limit its clinical application. Here, we report a rationally designed formulation of MIT-loaded nanoparticles (MIT-NPs) with a small size and sustained release for improved passive targeting and enhanced therapeutic efficacy. Nearly spherical MIT-NPs with a mean particle size of 25.0±4.6 nm were prepared by encapsulating MIT into methoxy poly(ethylene glycol)-block-poly(d,l-lactic-co-glycolic acid) (mPEG-PLGA) nanoparticles (NPs) with drug loading of 2.11%±0.51%. The in vitro release of the MIT-NPs lasted for >48 h with a sustained-release pattern. The cytotoxicity of MIT-NPs to human pancreatic cancer BxPC-3 and MIA Paca-2 cells was comparable to that of free MIT. Determined by flow cytometry and confocal microscopy, the NPs internalized into the cells quickly and efficiently, reaching the peak level at 1–2 h. In vivo fluorescence imaging showed that the prepared NPs were gradually accumulated in BxPC-3 and MIA Paca-2 xenografts and retained for 168 h. The fluorescence intensity in both BxPC-3 and MIA Paca-2 tumors was much stronger than that of various tested organs. Therapeutic efficacy was evaluated with the poorly permeable BxPC-3 pancreatic carcinoma xenograft model. At a well-tolerated dose of 2 mg/kg, MIT-NPs suppressed BxPC-3 tumor growth by 96%. Compared at an equivalent dose, MIT-NPs exerted significantly higher therapeutic effect than free MIT (86% versus 51%, P<0.01). Moreover, the treatment of MIT and MIT-NPs reduced the expression level of oncogene c-Myc regulated by Sp1, and notably, both of them decreased the protein level of CD47. In summary, the novel formulation of MIT-NPs shows highly therapeutic efficacy against pancreatic carcinoma xenograft. In addition, MIT-NPs can downregulate CD47 expression, implying that it might play a positive role in
Liu, Xu-Jie; Li, Liang; Liu, Xiu-Jun; Li, Yi; Zhao, Chun-Yan; Wang, Rui-Qi; Zhen, Yong-Su
Previous studies have shown that mithramycin A (MIT) is a promising candidate for the treatment of pancreatic carcinoma through inhibiting transcription factor Sp1. However, systemic toxicities may limit its clinical application. Here, we report a rationally designed formulation of MIT-loaded nanoparticles (MIT-NPs) with a small size and sustained release for improved passive targeting and enhanced therapeutic efficacy. Nearly spherical MIT-NPs with a mean particle size of 25.0±4.6 nm were prepared by encapsulating MIT into methoxy poly(ethylene glycol)-block-poly(d,l-lactic-co-glycolic acid) (mPEG-PLGA) nanoparticles (NPs) with drug loading of 2.11%±0.51%. The in vitro release of the MIT-NPs lasted for >48 h with a sustained-release pattern. The cytotoxicity of MIT-NPs to human pancreatic cancer BxPC-3 and MIA Paca-2 cells was comparable to that of free MIT. Determined by flow cytometry and confocal microscopy, the NPs internalized into the cells quickly and efficiently, reaching the peak level at 1-2 h. In vivo fluorescence imaging showed that the prepared NPs were gradually accumulated in BxPC-3 and MIA Paca-2 xenografts and retained for 168 h. The fluorescence intensity in both BxPC-3 and MIA Paca-2 tumors was much stronger than that of various tested organs. Therapeutic efficacy was evaluated with the poorly permeable BxPC-3 pancreatic carcinoma xenograft model. At a well-tolerated dose of 2 mg/kg, MIT-NPs suppressed BxPC-3 tumor growth by 96%. Compared at an equivalent dose, MIT-NPs exerted significantly higher therapeutic effect than free MIT (86% versus 51%, P<0.01). Moreover, the treatment of MIT and MIT-NPs reduced the expression level of oncogene c-Myc regulated by Sp1, and notably, both of them decreased the protein level of CD47. In summary, the novel formulation of MIT-NPs shows highly therapeutic efficacy against pancreatic carcinoma xenograft. In addition, MIT-NPs can downregulate CD47 expression, implying that it might play a positive role in
Wang, Chenhui; Yang, Jiebing; Han, Haobo; Chen, Jiawen; Wang, Yudi; Li, Quanshun; Wang, Yanbo
In this study, poly(lactic-co-glycolic acid) (PLGA) was used as a carrier to construct disulfiram-loaded porous microparticle through the emulsion solvent evaporation method, using ammonium bicarbonate as a porogen. The microparticle possessed highly porous surface, suitable aerodynamic diameter for inhalation (8.31±1.33 µm), favorable drug loading (4.09%±0.11%), and sustained release profile. The antiproliferation effect of release supernatant was detected through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay using non-small-cell lung cancer A549 as a model, with only 13.3% of cell viability observed for the release supernatant at 7 days. The antiproliferation mechanism was elucidated to be associated with the enhanced induction of cell apoptosis and cell cycle arrest at S phase through flow cytometry and Western blotting analysis. Finally, wound healing and transwell migration assay showed that they could efficiently inhibit the cell migration. These results demonstrated that disulfiram-loaded porous PLGA microparticle could achieve favorable antitumor efficiency, implying the potential of treating non-small-cell lung cancer in a pulmonary administration. PMID:28182125
Mudgil, Meetali; Pawar, Pravin K.
The aim of the present investigation was to prepare a colloidal ophthalmic formulation to improve the residence time of moxifloxacin. Moxifloxacin-loaded poly(dl-lactide-co-glycolide) (PLGA) nanosuspensions were prepared by using the solvent evaporation technique. The nanosuspensions were characterised physically by using different techniques like particle size, zeta potential, FTIR, DSC, and XRD analysis. In vitro and ex vivo studies of nanosuspensions were carried out using a modified USP dissolution apparatus and all-glass Franz diffusion cells, respectively. The antibacterial activities of the nanosuspension and marketed formulations were performed against S. aureus and P. aeroginosa. The moxifloxacin-loaded PLGA nanosuspensions showed uniform particle size, ranging between 164–490 nm with negative zeta potential for all batches. The percentage entrapment efficiency of the drug-loaded nano-suspension was found to be between 84.09 to 92.05%. In vitro drug release studies suggest that all of the formulations showed extended drug release profiles and follow Korsemeyer-Peppas release kinetics. In vitro corneal permeability was found to be comparable with that of the marketed formulation across isolated goat cornea, indicating the suitability of the nanosuspension formulation in the ophthalmic delivery of moxifloxacin. The optimised nano-suspension was found to be more active against S. aureus and P. aeruginosa compared to the marketed eye drops. PMID:23833723
Naseri, Marziyeh; Akbarzadeh, Abolfazl; Spotin, Adel; Akbari, Nagibeh Asl Rahnemaii; Mahami-Oskouei, Mahmoud; Ahmadpour, Ehsan
Treatment failures of human cystic echinococcosis (CE) with albendazole (ABZ) have attributed to its low solubility and poor drug absorption rate, resulting in low drug level in plasma. The scolicidal effects of ABZ-loaded liposome nanoparticles have recently evaluated; however, these particles have several challenges due to their low encapsulated load. This investigation was designed to evaluate and compare in vitro apoptotic activities of ABZ sulfoxide (ABZs) and ABZs-loaded poly(lactic-co-glycolic acid) (PLGA)-PEG against protoscoleces (PSCs). ABZs-loaded PLGA-PEG was prepared by a double-emulsion method (W1/O/W2). Various concentrations of ABZs and ABZs-loaded PLGA-PEG (50, 100, 150, and 200 μg/ml) were experimentally tested against PSC of CE at different exposure times (5, 10, 20, 30, and 60 min). ABZs-loaded PLGA-PEG at concentrations of 150 and 200 μg/ml was able to act at a 100 % scolicidal rate in all exposure times (5 to 60 min), while ABZs at a concentration of 200 μg/ml demonstrated 94, 100, and 100 % mortality rates following 20, 30, and 60 min of exposure times, respectively. The messenger RNA (mRNA) expression of caspase-3 was assessed by semi-quantitative RT-PCR after 15 h of exposure. Caspase-3 mRNA expression was higher in both PSC treated with ABZs and PSC treated with ABZs-loaded PLGA-PEG than that in control groups (P < 0.05). No significant difference was observed between the apoptotic intensity of PSC treated with ABZs and that of PSC treated with ABZs-loaded PLGA-PEG (P > 0.05). DNA fragmentation assay and ultrastructural changes revealed that ABZs and ABZs-loaded PLGA-PEG induced the apoptosis of PSC by activation of caspase-3. The higher permeability and scolicidal rate of ABZs-loaded PLGA-PEG can be addressed as an effectual alternative strategy to improve the treatment of human CE.
Mathew, Anila; Fukuda, Takahiro; Nagaoka, Yutaka; Hasumura, Takashi; Morimoto, Hisao; Yoshida, Yasuhiko; Maekawa, Toru; Venugopal, Kizhikkilot; Kumar, D Sakthi
Alzheimer's disease is a growing concern in the modern world. As the currently available medications are not very promising, there is an increased need for the fabrication of newer drugs. Curcumin is a plant derived compound which has potential activities beneficial for the treatment of Alzheimer's disease. Anti-amyloid activity and anti-oxidant activity of curcumin is highly beneficial for the treatment of Alzheimer's disease. The insolubility of curcumin in water restricts its use to a great extend, which can be overcome by the synthesis of curcumin nanoparticles. In our work, we have successfully synthesized water-soluble PLGA coated- curcumin nanoparticles and characterized it using different techniques. As drug targeting to diseases of cerebral origin are difficult due to the stringency of blood-brain barrier, we have coupled the nanoparticle with Tet-1 peptide, which has the affinity to neurons and possess retrograde transportation properties. Our results suggest that curcumin encapsulated-PLGA nanoparticles are able to destroy amyloid aggregates, exhibit anti-oxidative property and are non-cytotoxic. The encapsulation of the curcumin in PLGA does not destroy its inherent properties and so, the PLGA-curcumin nanoparticles can be used as a drug with multiple functions in treating Alzheimer's disease proving it to be a potential therapeutic tool against this dreaded disease.
Mathew, Anila; Fukuda, Takahiro; Nagaoka, Yutaka; Hasumura, Takashi; Morimoto, Hisao; Yoshida, Yasuhiko; Maekawa, Toru; Venugopal, Kizhikkilot; Kumar, D. Sakthi
Alzheimer's disease is a growing concern in the modern world. As the currently available medications are not very promising, there is an increased need for the fabrication of newer drugs. Curcumin is a plant derived compound which has potential activities beneficial for the treatment of Alzheimer's disease. Anti-amyloid activity and anti-oxidant activity of curcumin is highly beneficial for the treatment of Alzheimer's disease. The insolubility of curcumin in water restricts its use to a great extend, which can be overcome by the synthesis of curcumin nanoparticles. In our work, we have successfully synthesized water-soluble PLGA coated- curcumin nanoparticles and characterized it using different techniques. As drug targeting to diseases of cerebral origin are difficult due to the stringency of blood-brain barrier, we have coupled the nanoparticle with Tet-1 peptide, which has the affinity to neurons and possess retrograde transportation properties. Our results suggest that curcumin encapsulated-PLGA nanoparticles are able to destroy amyloid aggregates, exhibit anti-oxidative property and are non-cytotoxic. The encapsulation of the curcumin in PLGA does not destroy its inherent properties and so, the PLGA-curcumin nanoparticles can be used as a drug with multiple functions in treating Alzheimer's disease proving it to be a potential therapeutic tool against this dreaded disease. PMID:22403681
Kecel-Gündüz, Serda; Budama-Kilinc, Yasemin; Cakir Koc, Rabia; Kökcü, Yagmur; Bicak, Bilge; Aslan, Bahar; Özel, Aysen E
Phe-Tyr dipeptide which was investigated in Wakame food with greatest ACE-inhibitory activity is used as a pharmaceutical drug for the treatment of hypertension, cardiovascular diseases, and diabetic nephropathy. To improve the bioavailability of Phe-Tyr, a delivery system based on poly (lactic-co-glycolic acid) (PLGA) nanoparticles loaded with Phe-Tyr (Phe-Tyr-PLGA NPs) for treating hypertension and cardiovascular diseases was prepared in this study. In the experiments, poly(lactic-co-glycolic acid) (PLGA) and Phe-Tyr dipeptide-loaded PLGA nanoparticles were prepared using the double emulsion (w/o/w) method. The characterizations of the nanoparticles were performed with a UV-vis spectrometer, the Zeta-sizer system, and FTIR spectrometer. The optimum size of the Phe-Tyr dipeptide-loaded PLGA nanoparticle was obtained with a 213.8 nm average particle size, and a 0.061 polydispersity index, -19.5 mV zeta potential, 34% of loaded and 90.09% of encapsulation efficiency. From TEM analysis, it was clearly seen that the dipeptide loaded nanoparticles had the spherical and non-aggregated morphology and Phe-Tyr dipeptide loaded-PLGA nanoparticles were obtained successfully. Cell toxicity of nanoparticles at different concentrations was assayed with XTT methods on L929 fibroblast cells. This study determined that the nanoparticles have low toxicity at lower concentration and toxicity augmented with increasing concentration of dipeptide. To analyze the effect of solvents on structure of Phe-Tyr, Molecular dynamics simulation was performed with GROMACS program and molecular orbital calculations were carried out to obtain structural and electronic properties of dipeptide. Moreover, molecular docking calculations were also employed to model and predict protein-drug interactions.
Günday Türeli, Nazende; Türeli, Akif Emre; Schneider, Marc
Design of Experiments (DoE) is a powerful tool for systematic evaluation of process parameters' effect on nanoparticle (NP) quality with minimum number of experiments. DoE was employed for optimization of ciprofloxacin loaded PLGA NPs for pulmonary delivery against Pseudomonas aeruginosa infections in cystic fibrosis (CF) lungs. Since the biofilm produced by bacteria was shown to be a complicated 3D barrier with heterogeneous meshes ranging from 100nm to 500nm, nanoformulations small enough to travel through those channels were assigned as target quality. Nanoprecipitation was realized utilizing MicroJet Reactor (MJR) technology based on impinging jets principle. Effect of MJR parameters flow rate, temperature and gas pressure on particle size and PDI was investigated using Box-Behnken design. The relationship between process parameters and particle quality was demonstrated by constructed fit functions (R(2)=0.9934 p<0.0001 and R(2)=0.9983 p<0.0001, for particle size and PDI, respectively). Prepared nanoformulations varied between 145.2 and 979.8nm with PDI ranging from 0.050 to 1.00 and showed encapsulation efficiencies >65%. Response surface plots provided experimental data-based understanding of MJR parameters' effect, thus NP quality. Presented work enables ciprofloxacin loaded PLGA nanoparticle preparations with pre-defined quality to fulfill the requirements of local drug delivery under CF disease conditions. Copyright Â© 2016 Elsevier B.V. All rights reserved.
Siddharth, Sumit; Nayak, Anmada; Nayak, Deepika; Bindhani, Birendra Kumar; Kundu, Chanakya Nath
To overcome the toxicity, pharmacokinetics and drug resistance associated with doxorubicin (DOX), a strategy was developed by encapsulating DOX- loaded-PLGA-PVA- nanoparticles within chitosan-dextran sulfate nanoparticles (CS-DS) [CS-DS-coated-DOX-loaded -PLGA-PVA-NP] and study the sensitivity against DOX- resistance- breast cancer cells (MCF-7-DOX-R). These CS-DS and PLGA-PVA double coated DOX are spherical, stable, polydispersed and have zeta potential +2.89 mV. MCF-7- DOX-R cells were derived by exposing increasing doses of DOX in MCF-7 cells. These cells were resistance to 500 nM of DOX while parental cells were susceptible at 150 nM. The double coated NP caused more cytotoxicity in cancer and MCF-7-DOX-R cells without affecting the normal cells in comparison to DOX-loaded-PLGA-PVA-NP. These NP enhances the uptake of DOX in MCF-7-DOX-R cells and caused apoptosis by increasing apoptotic nuclei, Bax/Bcl-xL ratio, cleaved product PARP-1, tumor suppressor gene p21, p53, topoisomerase inhibition activity, DNA damage and decreasing the migratory potential of cells. An increased S phase arrest was noted in DOX and DOX- loaded- PLGA-PVA-NP treated cells but reduction of S phase and simultaneous increase of Sub-G1 was observed in double coated-NP. Thus, data revealed that CS-DS- DOX- loaded PLGA-PVA- NP caused DOX-resistance cell death by inducing inhibition of topoisomerase activity followed by DNA damage.
Deng, Wei; Kautzka, Zofia; Goldys, Ewa M.
In this study, poly(lactic-co-glycolic acid) (PLGA) nanocomposites were developed by incorporating a photosensitizer, verteporfin and gold nanoparticles into this polymeric matrix and utilised for enhanced photoynamic therapy. Both enhanced fluorescence and singlet oxygen generation from verteporfin were observed in this new formulation under both 425nm LED and 405nm laser illumination. A maximum enhancement factor of 2.5 for fluorescence and 1.84 for 1O2 generation was obtained when the molar ratio of gold:VP was 5:1 and excited at 425 nm, compared with PLGA doped with verteporfin only. The experiment results could be explained by the local electric field enhancement of gold nanoparticles. Furthermore, in vitro cell-killing effect on human pancreatic cancer cells was also demonstrated by using this new formulation following light exposure, indicating the utility of these nanocomposites for enhanced photodynamic therapy.
Das, Sreemanti; Khuda-Bukhsh, Anisur Rahman
Current treatment methods for melanoma have some limitations such as less target-specific action, severe side effects and resistance to drugs. Significant progress has been made in exploring novel drug delivery systems based on suitable biochemical mechanisms using nanoparticles ranging from 10 to 400 nm for drug delivery and imaging, utilizing their enhanced penetration and retention properties. Poly-lactide-co-glycolide (PLGA), a copolymer of poly-lactic acid and poly-glycolic acid, provides an ideally suited performance-based design for better penetration into skin cells, thereby having a greater potential for the treatment of melanoma. Moreover, encapsulation protects the drug from deactivation by biological reactions and interactions with biomolecules, ensuring successful delivery and bioavailability for effective treatment. Controlled and sustained delivery of drugs across the skin barrier that otherwise prohibits entry of larger molecules can be successfully made with adequately stable biocompatible nanocarriers such as PLGA for taking drugs through the small cutaneous pores permitting targeted deposition and prolonged drug action. PLGA is now being extensively used in photodynamic therapy and targeted therapy through modulation of signal proteins and drug-DNA interactions. Recent advances made on these nanomedicines and their advantages in the treatment of skin melanoma are highlighted and discussed in this review. PMID:27934796
Gu, Bing; Wang, Yan; Burgess, Diane J
The foreign body reaction is the major cause of the dysfunction and relatively short lifetime associated with implanted glucose biosensors. An effective strategy to maintain sensor functionality is to apply biocompatible coatings that elute drug to counter the negative tissue reactions. This has been achieved using dexamethasone releasing poly(lactic-co-glycolic acid) (PLGA) microspheres embedded in a polyvinyl alcohol (PVA) hydrogel coating. Accordingly, the biosensor lifetime relies on the duration and dose of drug release from the coating. To achieve long-term drug release mixed populations of microspheres have been used. In the current study, microspheres were prepared by blending low (25KDa) and high (113KDa) molecular weight PLGA at different mass ratios to overcome problems associated with mixing multiple populations of microspheres. "Real-time" in vitro studies demonstrated dexamethasone release for approximately 5 months. An accelerated method with discriminatory ability was developed to shorten drug release to less than 2 weeks. An in vivo pharmacodynamics study demonstrated efficacy against the foreign body reaction for 4.5 months. Such composite coatings composed of PLGA microspheres prepared using polymer blends could potentially be used to ensure long-term performance of glucose sensors.
Bowerman, Charles J; Byrne, James D; Chu, Kevin S; Schorzman, Allison N; Keeler, Amanda W; Sherwood, Candice A; Perry, Jillian L; Luft, James C; Darr, David B; Deal, Allison M; Napier, Mary E; Zamboni, William C; Sharpless, Norman E; Perou, Charles M; DeSimone, Joseph M
Novel treatment strategies, including nanomedicine, are needed for improving management of triple-negative breast cancer. Patients with triple-negative breast cancer, when considered as a group, have a worse outcome after chemotherapy than patients with breast cancers of other subtypes, a finding that reflects the intrinsically adverse prognosis associated with the disease. The aim of this study was to improve the efficacy of docetaxel by incorporation into a novel nanoparticle platform for the treatment of taxane-resistant triple-negative breast cancer. Rod-shaped nanoparticles encapsulating docetaxel were fabricated using an imprint lithography based technique referred to as Particle Replication in Nonwetting Templates (PRINT). These rod-shaped PLGA-docetaxel nanoparticles were tested in the C3(1)-T-antigen (C3Tag) genetically engineered mouse model (GEMM) of breast cancer that represents the basal-like subtype of triple-negative breast cancer and is resistant to therapeutics from the taxane family. This GEMM recapitulates the genetics of the human disease and is reflective of patient outcome and, therefore, better represents the clinical impact of new therapeutics. Pharmacokinetic analysis showed that delivery of these PLGA-docetaxel nanoparticles increased docetaxel circulation time and provided similar docetaxel exposure to tumor compared to the clinical formulation of docetaxel, Taxotere. These PLGA-docetaxel nanoparticles improved tumor growth inhibition and significantly increased median survival time. This study demonstrates the potential of nanotechnology to improve the therapeutic index of chemotherapies and rescue therapeutic efficacy to treat nonresponsive cancers.
Malinovskaya, Julia; Melnikov, Pavel; Baklaushev, Vladimir; Gabashvili, Anna; Osipova, Nadezhda; Mantrov, Sergey; Ermolenko, Yulia; Maksimenko, Olga; Gorshkova, Marina; Balabanyan, Vadim; Kreuter, Jörg; Gelperina, Svetlana
The paramount problem in the therapy of brain tumors is the inability of most drugs to cross the blood-brain barrier. PLGA nanoparticles overcoated with poloxamer 188 could overcome this problem and enabled a high anti-tumoral effect against the very aggressive intracranial 101.8 glioblastoma in rats that closely resembles human grade IV glioblastomas. The basis for the transport of these particles across the blood-brain barrier appears to be adsorption of blood apolipoproteins (ApoE or ApoA-I) on the nanoparticle surface caused by the poloxamer 188-coating, followed by receptor-mediated transcytosis of the nanoparticles. The objective of the present study is the elucidation of the mechanism by which the poloxamer 188-coated nanoparticles then enter the brain tumor cells. Their intracellular fate, therefore, was investigated using the U87 human glioma cell line. The main mechanism of the PLGA nanoparticle internalization by U87 cells was clathrin-mediated endocytosis. Within 1h free doxorubicin was released from late endosomes and could reach its target site, i.e. the DNA in the nuclei without degradation, whereas the PLGA nanoparticles, which were labeled with Cy5.5, still were observed in the endo-lysosomal compartment. These results demonstrate that the underlying mechanism of action in the brain cells is by diffusive doxorubicin release from the nanoparticles rather than by their intracellular degradation.
Courant, T; Roullin, V G; Cadiou, C; Delavoie, F; Molinari, M; Andry, M C; Chuburu, F
PLGA nanoparticles were prepared via a modified W/O/W emulsion solvent diffusion process, in which all formulation components were fully biocompatible and biodegradable. Different independent processing parameters were systematically studied. Nanoparticles were characterized by DLS (particle size, polydispersity, zeta-potential) and TEM/AFM (surface morphology). An optimized formulation was used to encapsulate copper complexes of cyclen and DOTA as potential PET imaging agents. Results showed that the predominant formulation factors appeared to be the lactide-to-glycolide (L:G) ratio of PLGA, the nature of the diffusion phase, and the presence of hydroxyl ions in the first-emulsion aqueous phase. By regulating those 3 parameters, PLGA nanoparticles were prepared with very good preparation yields (>95%), a size less than 200 nm and a polydispersity index less than 0.1. TEM pictures showed nanoparticles with a narrow size distribution, a spherical shape and a smooth surface. The optimized formulation allowed to encapsulate Cu-cyclen and Cu-DOTA complexes with an encapsulation efficiency between 20% and 25%.
Patil, Nilam H; Devarajan, Padma V
Alginic acid nanoparticles (NPs) containing insulin, with nicotinamide as permeation enhancer were developed for sublingual delivery. The lower concentration of proteolytic enzymes, lower thickness and enhanced retention due to bioadhesive property, were relied on for enhanced insulin absorption. Insulin-loaded NPs were prepared by mild and aqueous based nanoprecipitation process. NPs were negatively charged and had a mean size of ∼200 nm with low dispersity index. Insulin loading capacities of >95% suggested a high association of insulin with alginic acid. Fourier Transform Infra-Red Spectroscopy (FTIR) spectra and DSC (Differential Scanning Calorimetry) thermogram of insulin-loaded NPs revealed the association of insulin with alginic acid. Circular dichroism (CD) spectra confirmed conformational stability, while HPLC analysis confirmed chemical stability of insulin in the NPs. Sublingually delivered NPs with nicotinamide exhibited high pharmacological availability (>100%) and bioavailability (>80%) at a dose of 5 IU/kg. The high absolute pharmacological availability of 20.2% and bioavailability of 24.1% in comparison with subcutaneous injection at 1 IU/kg, in the streptozotocin-induced diabetic rat model, suggest the insulin-loaded alginic acid NPs as a promising sublingual delivery system of insulin.
Yin, Peihao; Wang, Yan; Qiu, YanYan; Hou, LiLi; Liu, Xuan; Qin, Jianmin; Duan, Yourong; Liu, Peifeng; Qiu, Ming; Li, Qi
Recent studies have shown that bufalin has a good antitumor effect but has high toxicity, poor water solubility, a short half-life, a narrow therapeutic window, and a toxic dose that is close to the therapeutic dose, which all limit its clinical application. This study aimed to determine the targeting efficacy of nanoparticles (NPs) made of methoxy polyethylene glycol (mPEG), polylactic-co-glycolic acid (PLGA), poly-L-lysine (PLL), and cyclic arginine-glycine-aspartic acid (cRGD) loaded with bufalin, ie, bufalin-loaded mPEG-PLGA-PLL-cRGD nanoparticles (BNPs), in SW620 colon cancer-bearing mice. BNPs showed uniform size. The size, shape, zeta potential, drug loading, encapsulation efficiency, and release of these nanoparticles were studied in vitro. The tumor targeting, cellular uptake, and growth-inhibitory effect of BNPs in vivo were tested. BNPs were of uniform size with an average particle size of 164 ± 84 nm and zeta potential of 2.77 mV. The encapsulation efficiency was 81.7% ± 0.89%, and the drug load was 3.92% ± 0.16%. The results of in vitro cytotoxicity studies showed that although the blank NPs were nontoxic, they enhanced the cytotoxicity of bufalin in BNPs. Drug release experiments showed that the release of the drug was prolonged and sustained. The results of confocal laser scanning microscopy indicated that BNPs could effectively bind to human umbilical vein endothelial cells. In the SW620 xenograft mice model, the BNPs could effectively target the tumor in vivo. The BNPs were significantly more effective than other NPs in preventing tumor growth. BNPs had even size distribution, were stable, and had a slow-releasing and tumor-targeting effect. BNPs significantly inhibited colon cancer growth in vitro and in vivo. As a novel drug carrier system, BNPs are a potentially promising targeting treatment for colon cancer.
Yin, Peihao; Wang, Yan; Qiu, YanYan; Hou, LiLi; Liu, Xuan; Qin, Jianmin; Duan, Yourong; Liu, Peifeng; Qiu, Ming; Li, Qi
Background: Recent studies have shown that bufalin has a good antitumor effect but has high toxicity, poor water solubility, a short half-life, a narrow therapeutic window, and a toxic dose that is close to the therapeutic dose, which all limit its clinical application. This study aimed to determine the targeting efficacy of nanoparticles (NPs) made of methoxy polyethylene glycol (mPEG), polylactic-co-glycolic acid (PLGA), poly-L-lysine (PLL), and cyclic arginine-glycine-aspartic acid (cRGD) loaded with bufalin, ie, bufalin-loaded mPEG-PLGA-PLL-cRGD nanoparticles (BNPs), in SW620 colon cancer-bearing mice. Methods: BNPs showed uniform size. The size, shape, zeta potential, drug loading, encapsulation efficiency, and release of these nanoparticles were studied in vitro. The tumor targeting, cellular uptake, and growth-inhibitory effect of BNPs in vivo were tested. Results: BNPs were of uniform size with an average particle size of 164 ± 84 nm and zeta potential of 2.77 mV. The encapsulation efficiency was 81.7% ± 0.89%, and the drug load was 3.92% ± 0.16%. The results of in vitro cytotoxicity studies showed that although the blank NPs were nontoxic, they enhanced the cytotoxicity of bufalin in BNPs. Drug release experiments showed that the release of the drug was prolonged and sustained. The results of confocal laser scanning microscopy indicated that BNPs could effectively bind to human umbilical vein endothelial cells. In the SW620 xenograft mice model, the BNPs could effectively target the tumor in vivo. The BNPs were significantly more effective than other NPs in preventing tumor growth. Conclusion: BNPs had even size distribution, were stable, and had a slow-releasing and tumor-targeting effect. BNPs significantly inhibited colon cancer growth in vitro and in vivo. As a novel drug carrier system, BNPs are a potentially promising targeting treatment for colon cancer. PMID:22888239
Samadder, Asmita; Das, Jayeeta; Das, Sreemanti; De, Arnab; Saha, Santu Kumar; Bhattacharyya, Soumya Sundar; Khuda-Bukhsh, Anisur Rahman
Diabetes is a menacing problem, particularly to inhabitants of groundwater arsenic contaminated areas needing new medical approaches. This study examines if PLGA loaded nano-insulin (NIn), administered either intraperitoneally (i.p.) or through oral route, has a greater cost-effective anti-hyperglycemic potential than that of insulin in chronically arsenite-fed hyperglycemic mice. The particle size, morphology and zeta potential of nano-insulin were determined using dynamic light scattering method, scanning electronic and atomic force microscopies. The ability of the nano-insulin (NIn) to cross the blood–brain barrier (BBB) was also checked. Circular dichroic spectroscopic (CD) data of insulin and nano-insulin in presence or absence of arsenic were compared. Several diabetic markers in different groups of experimental and control mice were assessed. The mitochondrial functioning through indices like cytochrome c, pyruvate-kinase, glucokinase, ATP/ADP ratio, mitochondrial membrane potential, cell membrane potential and calcium-ion level was also evaluated. Expressions of the relevant marker proteins and mRNAs like insulin, GLUT2, GLUT4, IRS1, IRS2, UCP2, PI3, PPARγ, CYP1A1, Bcl2, caspase3 and p38 for tracking-down the signaling cascade were also analyzed. Results revealed that i.p.-injected nano-encapsulated-insulin showed better results; NIn, due to its smaller size, faster mobility, site-specific release, could cross BBB and showed positive modulation in mitochondrial signaling cascades and other downstream signaling molecules in reducing arsenic-induced-hyperglycemia. CD data indicated that nano-insulin had less distorted secondary structure as compared with that of insulin in presence of arsenic. Thus, overall analyses revealed that PLGA nano-insulin showed better efficacy in combating arsenite-induced-hyperglycemia than that of insulin and therefore, has greater potentials for use in nano-encapsulated form. - Highlights: ► PLGA encapsulated nano-insulin
Ganguly, Soumya; Gaonkar, Raghuvir H.; Sinha, Samarendu; Gupta, Amit; Chattopadhyay, Dipankar; Chattopadhyay, Sankha; Sachdeva, Satbir S.; Ganguly, Shantanu; Debnath, Mita C.
The purpose of this study was to develop surfactant-free quercetin-loaded PLGA nanoparticles (Qr-NPs) and investigate the hepatoprotective efficacy of the product non-invasively by nuclear scintigraphy. The nanoparticles were prepared using PLGA by dialysis method and ranged in size between 50 and 250 nm with a narrow range of distribution. They were found to arrive at the fenestra of liver sinusoidal epithelium for accumulation. The sizes of nanoparticles (batch S1) were optimal to reach the target and offer enough protection of the hepatocytes degenerated by CCl4 intoxication as determined by various biochemical and histopathological tests. In vitro studies exhibited the cytotoxic effect of the formulation against HepG2 cell line. The hepatoprotective efficacy of Qr-NPs evaluated non-invasively by nuclear scintigraphic technique using 99mTc-labelled sulphur colloid revealed abnormality in liver at the area of decreased uptake in rats of CCl4-treated group, which disappeared in Qr-NP-treated group. In dynamic studies with 99mTc-mebrofenin, excretion was severely impaired in CCl4-treated group but was moderate in drug-treated group, proving the recovery of animals from damage.
Herrero-Vanrell, R; Ramirez, L; Fernandez-Carballido, A; Refojo, M F
The purpose of this work was to obtain a sterilized formulation consisting of biodegradable microspheres of poly (DL-lactide-co-glycolide) (PLGA) for intraocular sustained release of ganciclovir. Microspheres were prepared using a dispersion of ganciclovir in fluorosilicone oil (FSiO) that was further dispersed in an acetone solution of PLGA [50/50 and inherent viscosity 0.41 dl/g], and emulsified in silicone oil with a surfactant. Once prepared, the formulation was exposed with an effective gamma radiation dose of 2.5 megarads. The release rate data of ganciclovir from the sterilized and nonsterilized batches were compared using the similarity factor (f2). The dispersion of the drug in FSiO contributed to achieving a drug payload of up to 95% of the theoretical in the 300-500 microm microspheres. Ten mg released ganciclovir in vitro at 1.3 microg/h for the first 21 days, but decreased to approximately 0.2 microg/h from day 25 until the end of the release study (42 days). No significant differences in the amounts of encapsulated drug (alpha = 0.05) were observed between the sterilized and nonsterilized microspheres. Furthermore, dissolution profiles of formulations behaved similarly before and after gamma radiation exposure. The technique of microsphere preparation described resulted in high ganciclovir loading (95%) and prolonged drug release. The ganciclovir formulation behaved similarly before and after the sterilization process.
Rahimi, Mehdi; Mobedi, Hamid; Behnamghader, Aliasghar
Drug release mechanism of in situ-forming implants (ISIs) based on poly(lactic acid-co-glycolic acid) (PLGA) loaded with leuprolide acetate/β-cyclodextrin (LA/β-CD) complexes via fitting with four diffusion-based semi-empirical models were studied. The release rate constants and release exponent of ISIs were calculated. The main drug release mechanism was Fickian diffusion. The LA diffusion coefficient and release constant were decreased via increasing the portion of β-CD in complexes. The release curve was parabolic, with a higher initial slope and then consistent with the exponential. All ISIs containing LA/β-CD complexes better fitted with the Korsmeyer-Peppas, Weibull and Peppas-Sahlin models rather than first-order model. Furthermore, the effect of LA/β-CD complexation on the degradation of ISIs was studied through scanning electron microscopy (SEM). Results showed that hydrophilic nature of β-CD facilitated the surface erosion of PLGA chains, however after 18 d, ISI-1/10 had still a proper structural strength, due to no hydrolytic degradation of β-CD in this implant.
Samadder, Asmita; Das, Jayeeta; Das, Sreemanti; De, Arnab; Saha, Santu Kumar; Bhattacharyya, Soumya Sundar; Khuda-Bukhsh, Anisur Rahman
Diabetes is a menacing problem, particularly to inhabitants of groundwater arsenic contaminated areas needing new medical approaches. This study examines if PLGA loaded nano-insulin (NIn), administered either intraperitoneally (i.p.) or through oral route, has a greater cost-effective anti-hyperglycemic potential than that of insulin in chronically arsenite-fed hyperglycemic mice. The particle size, morphology and zeta potential of nano-insulin were determined using dynamic light scattering method, scanning electronic and atomic force microscopies. The ability of the nano-insulin (NIn) to cross the blood-brain barrier (BBB) was also checked. Circular dichroic spectroscopic (CD) data of insulin and nano-insulin in presence or absence of arsenic were compared. Several diabetic markers in different groups of experimental and control mice were assessed. The mitochondrial functioning through indices like cytochrome c, pyruvate-kinase, glucokinase, ATP/ADP ratio, mitochondrial membrane potential, cell membrane potential and calcium-ion level was also evaluated. Expressions of the relevant marker proteins and mRNAs like insulin, GLUT2, GLUT4, IRS1, IRS2, UCP2, PI3, PPARγ, CYP1A1, Bcl2, caspase3 and p38 for tracking-down the signaling cascade were also analyzed. Results revealed that i.p.-injected nano-encapsulated-insulin showed better results; NIn, due to its smaller size, faster mobility, site-specific release, could cross BBB and showed positive modulation in mitochondrial signaling cascades and other downstream signaling molecules in reducing arsenic-induced-hyperglycemia. CD data indicated that nano-insulin had less distorted secondary structure as compared with that of insulin in presence of arsenic. Thus, overall analyses revealed that PLGA nano-insulin showed better efficacy in combating arsenite-induced-hyperglycemia than that of insulin and therefore, has greater potentials for use in nano-encapsulated form. Copyright © 2012 Elsevier Inc. All rights reserved.
Abou-El-Naga, Iman Fathy; El Kerdany, Eman Dorry; Mady, Rasha Fadly; Shalaby, Thanaa Ibrahim; Zaytoun, Enas Mohammed
A marked reduction has been achieved in the incidence and clinical course of toxoplasmic encephalitis after the introduction of protease inhibitors within the treatment regimen of HIV (HIV-PIs). This work was undertaken to study for the first time, the efficacy of HIV-PIs, lopinavir/ritonavir (L/R), as a therapeutic agent in acute experimental toxoplasmosis. Lopinavir/ritonavir (L/R) were used in the same ratio present in aluvia, a known HIV-PIs drug used in the developing countries in the treatment regimens of AID's patient. Poly lactic-co-glycolic acid (PLGA) nanoparticles were used as a delivery system to L/R therapy. L/R alone or after its encapsulation on PLGA were given to Swiss strain albino mice that were infected with RH virulent toxoplasma strain. Both forms caused parasitological improvement in both mortality rate and parasite count. The higher efficacy was achieved by using L/R PLGA together with minimizing the effective dose. There was significant reduction in the parasite count in the peritoneal fluid and the liver. Parasite viability and infectivity were also significantly reduced. The anti-toxoplasma effect of the drug was attributed to the morphological distortion of the tachyzoites as evident by the ultrastructure examination and suppressed the egress of tachyzoites. L/R also induced changes that suggest apoptosis and autophagy of tachyzoites. The parasitophorous vacuole membrane was disrupted and vesiculated. The nanotubular networks inside the parasitophorous vacuole were disrupted. Therefore, the present work opens a new possible way for the approved HIV-PIs as an alternative treatment against acute toxoplasmosis. Furthermore, it increases the list of the opportunistic parasites that can be treated by this drug. The successful in vivo effect of HIV-PIs against Toxoplasma gondii suggests that this parasite may be a target in HIV treated patients, thus decrease the possibility of toxoplasmic encephalitis development. Copyright © 2017. Published
Öğünç, Yüksel; Demirel, Müzeyyen; Yakar, Arzu; İncesu, Zerrin
The objective of this study was to prepare the ɛ-viniferine and vincristine-loaded PLGA-b-PEG nanoparticle and to investigate advantages of these formulations on the cytotoxicity of HepG2 cells. Prepared nanoparticle has shown a homogeneous distribution with 113 ± 0.43 nm particle size and 0.323 ± 0.01 polydispersity index. Zeta potential was determined as -35.03 ± 1.0 mV. The drug-loading percentages were 6.01 ± 0.23 and 2.01 ± 0.07 for ɛ-viniferine and vincristine, respectively. The cellular uptake efficiency of coumarin-6-loaded nanoparticles was increased up to 87.8% after 4 h. Nanoparticles loaded with high concentrations of both drugs showed a cytotoxic effect on HepG2 cells, having the percentage of cell viability of between 43.23% and 47.37%. Unfortunately, the percentage of apoptotic cells after treated with drugs-loaded nanaoparticles (10.93%) was similar to free forms of drugs (12.1%) that might be due to low ɛ-viniferine release in biological pH at 24 h.
Kang, Han Chang; Lee, Ji Eun; Bae, You Han
Poly(lactide-co-glycolide) (PLGA) has most often been employed for the controlled release of protein formulations because of its safety profile with non-toxic degradation products. Nevertheless, such formulations have been plagued by a local acidic microenvironment and protein-polymer interactions, which result in chemical and physical denaturation of loaded proteins and often unfavorable release profiles. This study investigated the pH change of inner PLGA microsphere (MS) using charged (PLGA)n-b-branched polyethyleneimine (bPEI) micelles. The designed micelles can be transformed into either micelle or reverse micelle (RM) depending on the solvent and RM can form microspheres. In addition, (PLGA)n-b-bPEI can be modified into (PLGA)n-b-(carboxylated bPEI) via carboxylation of the primary amines. Cationic micelle (CM) or anionic micelle (AM) were complexed with counter-charged proteins leading to nanosized particles (approximately 100 nm). In the micelle/protein complexes, the micelles mostly maintained their proton buffering capacity, and consequently, prevented or delayed the typical decrease in pH caused by degradation of PLGA in aqueous solution. Reconstitutable micelle/protein complexes allowed for increased and fine-tuned protein loading (~20 wt% when using CM1 (CM prepared from PLGA36kDa-b-bPEI25kDa)/insulin complexes) in PLGA MS. In CM2 (CM prepared from (PLGA36kDa)2-b-bPEI25kDa)/insulin (4 of weight ratio (WR) of micelle to protein; WR4)-loaded PLGA MS, CM2 strongly prevented the micellar nanoenvironmental pH (pH 6.6 within 5 days and then approximately pH 8.5) to be acidified in PLGA MS for 9 weeks, unlike CM2-free PLGA MS. In conclusion, our findings propose that the proton buffering capacity and protein loading in PLGA MS can be tuned by controlling the complexation ratios of micelles and proteins, polymeric architectures of (PLGA)n-b-bPEI copolymers and WR of micelle/protein complexes and PLGA (or RM). PMID:22405902
Packhaeuser, C B; Kissel, T
The feasibility to generate in situ forming parenteral depot systems from insulin loaded dialkylaminoalkyl-amine-poly(vinyl alcohol)-g-poly(lactide-co-glycolide) nanoparticles, was investigated. Biodegradable nanoparticles formed polymeric semi-solid depots upon injection into isotonic phosphate buffered saline (PBS) with no additional initiators. Nanoparticles (NP) prepared from the different amine-modified polyesters displayed a pronounced positive zeta-potential of >25 mV. Diethylaminopropyl-amine-poly(vinyl alcohol)-g-poly(lactide-co-glycolide) (DEAPA(68)-PVAL-g-PLGA(1:20)), diethylaminoethyl-amine-poly(vinyl alcohol)-g-poly(lactide-co-glycolide) (DEAEA(33)-PVAL-g-PLGA(1:20)), and dimethylaminopropyl-amine-poly(vinyl alcohol)-g-poly(lactide-co-glycolide) (DMAPA(33)-PVAL-g-PLGA(1:20)), formed in situ depots by an ion-mediated aggregation with subsequent fusion of nanoparticles, related to a decreased glass transition temperature in the presence of PBS. Moreover, two factors, namely, polymer and insulin-nanocomplex concentration, were evaluated using a response surface design with respect to nanoparticles formation and insulin loading. Nanoparticles and implants were investigated by atomic force microscopy (AFM). The in vitro release from implants loaded with 2% insulin was carried out in a flow trough cell and quantified by high performance liquid chromatography (HPLC). The release showed a triphasic profile with an initial burst, pore diffusion and diffusion from the swollen matrix over more than two weeks. Insulin distribution in the implants during the release was followed by confocal laser scanning microscopy (CLSM). These findings combined with the protection of the model peptide against competitive macromolecules and the possibility to get dry powders by lyophilization make these nanoparticles-based depots suitable candidates for the design of controlled release devices for bioactive macromolecules.
Chuda, Chittasupho; Sheng-Xue, Xie; Abdulgader, Baoum; Tatyana, Yakovleva; Teruna, Siahaan J.; Cory, Berkland
Interaction of leukocyte function associated antigen-1 (LFA-1) on T-lymphoctytes and intercellular adhesion molecule-1 (ICAM-1) on epithelial cells controls leukocyte adhesion, spreading, and extravasation. This process plays an important role in leukocyte recruitment to a specific site of inflammation and has been indentified as a biomarker for certain types of carcinomas. Cyclo-(1,12)-PenITDGEATDSGC (cLABL) has been shown to inhibit LFA-1 and ICAM-1 interaction via binding to ICAM-1. In addition, cLABL has been shown to internalize after binding ICAM-1. The possibility of using cLABL conjugated nanoparticles (cLABL-NP) as a targeted and controlled release drug delivery system has been investigated in this study. The cLABL peptide was conjugated to a modified Pluronic® surfactant on poly (DL-lactic-co-glycolic acid) (PLGA) nanoparticles. The cLABL-NP showed more rapid cellular uptake by A549 lung epithelial cells compared to nanoparticles without peptide. The specificity of ICAM-1 mediated internalization was confirmed by blocking the uptake of cLABL-NP to ICAM-1 using free cLABL peptide to block the binding of cLABL-NP to ICAM-1 on the cell surface. Cell studies suggested that cLABL-NPs targeted encapsulated doxorubicin to ICAM-1 expressing cells. Cytotoxicity assay confirmed the activity of the drug incorporated in nanoparticles. Sustained release of doxorubicin afforded by PLGA nanoparticles may enable cLABL-NP as a targeted, controlled release drug delivery system. PMID:19429421
Chen, Cen; Yang, Wei; Wang, Dan-Tong; Chen, Chao-Long; Zhuang, Qing-Ye; Kong, Xiang-Dong
To improve the anti-tumor activity of hydrophobic drug curcumin, we prepared curcumin-loaded PLGA nanoparticles (PLGA-Cur NPs) through a modified spontaneous emulsification solvent diffusion (modified-SESD) method. The influence of main preparation parameters was investigated, such as the volume ratio of binary organic solvents and the concentration of surfactant. Results indicated that the synthesized regular spherical PLGA NPs with the average diameter of 189.7 nm exhibited relatively higher yield (58.9%), drug loading (11.0% (w/w)) and encapsulation efficiency (33.5%), and also a controllable drug release profile. In order to evaluate the in vitro cytotoxicity of the prepared NPs, MTT assay was conducted, and results showed that the NPs could effectively inhibit HL60 and HepG2 cells with lower IC50 values compared with free curcumin. Furthermore, confocal microscopy together with flow cytometry analysis proved the enhanced apoptosis-inducing ability of PLGA-Cur NPs. Polymeric NP formulations are potential to be used for hydrophobic drug delivery systems in cancer therapy.
Schiller, Stefan; Hanefeld, Andrea; Schneider, Marc; Lehr, Claus-Michael
Although nanomaterials are under investigation for a very broad range of medical applications, only a small fraction of these are already commercialized or in clinical development. A major challenge for the translation of nanomedicines into the clinic is the missing scalability of the available lab scale preparation methods and, ultimately, non-identical samples during early and late research. Protein-loaded PLGA nanoparticles using focused ultrasound in an emulsion solvent diffusion method were prepared in different batch sizes to evaluate achievable mean size, protein loading, and yield. Using the same equipment, nanoparticles could be prepared in batch sizes from 1 mg to 2.5 g. Size and yield were directly controllable by the amount of incident energy with good reproducibility. The nanoparticles displayed similar mean size, protein loading, and nanoparticle yield in batch sizes over three orders of magnitude. A scalable purification method based on diafiltration was established. The proposed method enables for feasibility studies during early research using just a small amount of polymer and protein, while at the same time it allows for larger scale production at later stages. As the proposed method further relies on contact-free energy transmission, it is especially suited for the preparation of clinical research samples.
Cheng, Lihua; Jin, Chengmeng; Lv, Wen; Ding, Qiuping; Han, Xu
Background Cisplatin is a potent anticancer drug, but its clinical application has been limited due to its undesirable physicochemical characteristics and severe side effects. Better drug formulations for cisplatin are highly desired. Methodology/Principal Findings Herein, we have developed a nanoparticle formulation for cisplatin with high encapsulation efficiency and reduced toxicity by using cisplatin-crosslinked carboxymethyl cellulose (CMC) core nanoparticles made from poly(lactide-co-glycolide)-monomethoxy-poly(polyethylene glycol) copolymers (PLGA-mPEG). The nanoparticles have an average diameter of approximately 80 nm measured by transmission electron microscope (TEM). The encapsulation efficiency of cisplatin in the nanoparticles is up to 72%. Meanwhile, we have also observed a controlled release of cisplatin in a sustained manner and dose-dependent treatment efficacy of cisplatin-loaded nanoparticles against IGROV1-CP cells. Moreover, the median lethal dose (LD50) of the cisplatin-loaded nanoparticles was more than 100 mg/kg by intravenous administration, which was much higher than that of free cisplatin. Conclusion This developed cisplatin-loaded nanoparticle is a promising formulation for the delivery of cisplatin, which will be an effective therapeutic regimen of ovarian cancer without severe side effects and cumulative toxicity. PMID:21966528
Gan, Mengyue; Zhang, Wenping; Wei, Shijie; Dang, Hongwan
The influence of mPEG-PCL and mPEG-PLGA on encapsulation efficiency and drug-loading of nanoparticles was very important. SN-38 NPs were prepared from a series of diblock copolymers: mPEG1000-PLGA2000, mPEG2000-PCLs, mPEG5000-PCLs, mPEG2000-PLGAs, and mPEG5000-PLGAs by the thin film-hydration method. The prepared nanoparticles were characterized by morphology, size, encapsulation efficiency, drug-loading, and in vitro release behavior. This experiment suggested that the encapsulation efficiency and drug-loading of SN-38 NPs were attained the maximum values when the ratio of hydrophilic to hydrophobic block was between 1:2 and 1:3.
Chang, Nai-Jen; Lin, Chih-Chan; Shie, Ming-You; Yeh, Ming-Long; Li, Chien-Feng; Liang, Peir-In; Lee, Kuan-Wei; Shen, Pei-Hsun; Chu, Chih-Jou
The regeneration of hyaline cartilage remains clinically challenging. Here, we evaluated the therapeutic effects of using cell-free porous poly(lactic-co-glycolic acid) (PLGA) graft implants (PGIs) along with early loading exercise to repair a full-thickness osteochondral defect. Rabbits were randomly allocated to a treadmill exercise (TRE) group or a sedentary (SED) group and were prepared as either a PGI model or an empty defect (ED) model. TRE was performed as a short-term loading exercise; SED was physical inactivity in a free cage. The knees were evaluated at 6 and 12 weeks after surgery. At the end of testing, none of the knees developed synovitis, formed osteophytes, or became infected. Macroscopically, the PGI-TRE group regenerated a smooth articular surface, with transparent new hyaline-like tissue soundly integrated with the neighboring cartilage, but the other groups remained distinct at the margins with fibrous or opaque tissues. In a micro-CT analysis, the synthesized bone volume/tissue volume (BV/TV) was significantly higher in the PGI-TRE group, which also had integrating architecture in the regeneration site. The thickness of the trabecular (subchondral) bone was improved in all groups from 6 to 12 weeks. Histologically, remarkable differences in the cartilage regeneration were visible. At week 6, compared with SED groups, the TRE groups manifested modest inflammatory cells with pro-inflammatory cytokines (i.e., TNF-α and IL-6), improved collagen alignment and higher glycosaminoglycan (GAG) content, particularly in the PGI-TRE group. At week 12, the PGI-TRE group had the best regeneration outcomes, showing the formation of hyaline-like cartilage, the development of columnar rounded chondrocytes that expressed enriched levels of collagen type II and GAG, and functionalized trabecular bone with osteocytes. In summary, the combination of implanting cell-free PLGA and performing an early loading exercise can significantly promote the full
Mao, Jingsong; Tang, Shunsong; Hong, Duo; Zhao, Fan; Niu, Meng; Han, Xiangjun; Qi, Ji; Bao, Han; Jiang, Yutian; Fu, Changhui; Long, Dan; Meng, Xianwei; Su, Hongying
The use of nanomaterials as drug delivery systems shows good effects in treating tumors. However, the effective dose of drugs targeted to tumor tissues is very low because of the effect of the reticuloendothelial system (RES) in removing such foreign substances. In order to eliminate the RES effect, we developed mPEG-PLGA@ZrO2@(DOX + ILS) (mPEG-PLGA@ZrO2@[DOX + ILS]) drug-loaded microspheres. These microwave (MW)-sensitized microspheres directly embolized the blood-supply vessels of tumors to induce tumor ischemia and hypoxia, as well as to aggregate drugs within tumor tissues in a long-lasting manner. Additionally, combination with MW ablation can triple the effects for the inhibition of tumor growth. The MW sensitive ionic liquid (ILS) in microspheres can rapidly produce a high temperature in a MW field on the basis of MW sensitization, thus accelerating the degradation of microspheres to release DOX-loaded ZrO2 into the lesions to kill tumors. Microspheres can also prolong the pharmacological time and effect of drugs through the enhanced permeability and retention (EPR) effect of nanocarriers, as well as the sustained release of nanomaterials. Studies performed in vivo revealed that mPEG-PLGA@ZrO2@(DOX + ILS) showed good biosafety. We undertook sensitized microsphere embolism therapy using novel mPEG-PLGA@ZrO2@(DOX + ILS) microspheres in a rabbit VX2 liver tumor model. Three, 6 and 9 d after treatment, computed tomography indicated no significant change in tumor size, and diffusion weighted imaging showed a marked decrease of residual tumor tissues. With the multiple functions of inducing embolisms, sensitization, and the sustained release of chemotherapeutics, novel mPEG-PLGA@ZrO2@(DOX + ILS) microspheres can achieve good therapeutic efficacy, in combination with MW ablation and chemotherapy, while embolizing the blood vessels of arterial tumors.
Le Broc-Ryckewaert, D; Carpentier, R; Lipka, E; Daher, S; Vaccher, C; Betbeder, D; Furman, C
Taxanes, including paclitaxel, are anti-cancer drugs approved for the treatment of prostate cancer but which have limited clinical application due to their hydrophobicity, their low therapeutic index and the emergence of chemoresistance. These side effects may be avoided through the use of new drug delivery systems such as nanoparticles, and paclitaxel-loaded PLGA nanoparticles up to 200 nm in size have shown encouraging results. As it is known that size affects the tissular penetration and distribution of tumors via the enhanced permeability and retention effect, so nanoparticles smaller than 100 nm are potentially interesting vehicles for improving paclitaxel delivery and efficacy. In this work, new paclitaxel-loaded small PLGA nanoparticles, between 49 nm and 95 nm in size and with positive or negative surface charges, were prepared without detergent. They were stable in the presence of serum, and HPLC showed that high paclitaxel loading and stability were achieved. Intracellular uptake of these nanoparticles was studied in PC3 cells by flow cytometry. Confocal studies confirmed a high tubulin destructuration at very low dose with these nanoparticles. This study suggests that both positively and negatively charged paclitaxel-loaded small PLGA nanoparticles deliver this drug into PC3 cells, and that this nanoparticle mode of delivery highly improves paclitaxel efficiency by up to two log-increase. These results also highlight the importance of small nanoparticles for drug delivery in cancer applications and are extremely promising for in vivo studies. Copyright © 2013 Elsevier B.V. All rights reserved.
Bohrey, Sarvesh; Chourasiya, Vibha; Pandey, Archna
The objective of the present work was to develop and optimize olanzapine loaded polymeric nanoparticles using a factorial design. The presented work developed and optimized olanzapine loaded polymeric nanoparticles by using a 33 factorial design. The 33 factorial design was used for studying the effect of the main preparation variables on particle size and percent drug entrapment efficiency of the nanoparticles. A modified nanoprecipitation method was used to prepare nanoparticles successfully by using the biodegradable polymer poly(lactic-co-glycolic)acid (PLGA), and they were characterized for various parameters such as particle size, shape, zeta potential, percent drug entrapment efficiency, percent process yield and in vitro drug release behavior. Examination of the interaction between the excipients used as well as investigation of the nature of the drug, the formulation and the nature of the drug in the formulations was carried out by FTIR studies. Different kinetic models were used to analyze the in vitro drug release data. The preferred formulation showed a particle size of 127.6 ± 1.9 nm, PDI of 0.239 ± 0.013, zeta potential of -29.2 mV, entrapment efficiency of 72.46 ± 3.8% and process yield of 89.65 ± 1.3%. TEM results showed that these nanoparticles were spherical in shape and follow the Korsmeyer-Peppas model with different release exponent values.
Dai, Juan; Long, Wei; Liang, Zhongping; Wen, Lu; Yang, Fan; Chen, Gang
Delivery of biomacromolecular drugs into the inner ear is challenging, mainly because of their inherent instability as well as physiological and anatomical barriers. Therefore, protein-friendly, hydrogel-based delivery systems following local administration are being developed for inner ear therapy. Herein, biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) containing interferon α-2 b (IFN α-2 b) were loaded in chitosan/glycerophosphate (CS/GP)-based thermosensitive hydrogel for IFN delivery by intratympanic injection. The injectable hydrogel possessed a physiological pH and formed semi-solid gel at 37 °C, with good swelling and deswelling properties. The CS/GP hydrogel could slowly degrade as visualized by scanning electron microscopy (SEM). The presence of NPs in CS/GP gel largely influenced in vitro drug release. In the guinea pig cochlea, a 1.5- to 3-fold increase in the drug exposure time of NPs-CS/GP was found than those of the solution, NPs and IFN-loaded hydrogel. Most importantly, a prolonged residence time was attained without obvious histological changes in the inner ear. This biodegradable, injectable, and thermosensitive NPs-CS/GP system may allow longer delivery of protein drugs to the inner ear, thus may be a potential novel vehicle for inner ear therapy.
Negro, Sofía; Boeva, Liudmilla; Slowing, Karla; Fernández-Carballido, Ana; García-García, Luis; Barcia, Emilia
A new controlled delivery system is developed for ropinirole (RP) for the treatment of Parkinson´s disease (PD) consisting in PLGA microparticles (MPs) which exhibited in vitro constant release of RP (78.23 µg/day/10 mg MPs) for 19 days. The neuroprotective effects of RP released from MPs are evaluated in SKN-AS cells after exposure to rotenone (20 μM). Cell apoptosis was significantly reduced by RP (100-120 μM). Daily doses of rotenone (2 mg/kg) given i.p. to rats induced neuronal and behavioral changes similar to those of PD. After 15 days animals received RP in saline (1 mg/kg/day for 45 days) or as MPs at two dose levels (amount of MPs equivalent to 7.5 mg/kg or 15 mg/kg RP given on days 15 and 30). Brain immunochemistry (Nissl-staining, GFAP and TH immunohistochemistry) and behavioral testing (catalepsy, akinesia, rotarod and swim test) showed that animals receiving RP either in solution or encapsulated within MPs reverted PD symptoms with the best results obtained in animals receiving RP microspheres at the highest dose assayed, thereby confirming the potential therapeutic interest of the new RP delivery system.
Das, Nilanjana; Madan, Parshotam; Lin, Senshang
The principle of statistical optimization was employed to fabricate insulin-loaded Pluronic F-127 (PF-127) gel formulations having the potential for buccal delivery of basal insulin. A two-level resolution III fractional factorial design was applied to simultaneously evaluate five independent formulation variables: PF-127 concentration, insulin concentration, sodium sulfate concentration, hydroxypropylmethyl cellulose (HPMC) concentration, and presence of sodium glycocholate. The amount of insulin released and permeated from gels as well as gelation time and mucoadhesion force of gels were measured and used as dependent response variables for formulation optimization. Optimization of a gel formulation was achieved by applying constrained optimization via regression analysis. In vitro permeation flux of insulin from the optimized formulation through procine buccal mucosa was 93.17 (±0.058, n = 3) μg/cm(2). Plasma insulin levels following buccal administration of the optimized formulation at 10, 25 and 50 IU/kg to healthy rats were found to be dose dependent and basal insulin levels were maintained at least for 8 h. Furthermore, continuous hypoglycemia for at least 8 h was observed with 89%, 51% and 25% of blood glucose reduction, respectively, for these three doses. The results of this investigation conclude the feasibility of development of optimized buccal insulin-loaded Pluronic F-127 gels for basal insulin delivery.
Duan, Yourong; Sun, Xun; Gong, Tao; Wang, Qi; Zhang, Zhirong
This study describes the preparation and the evaluation of biodegradation monomethoxy (polyethylene glycol)-poly (lactide-co-glycolide)-monomethoxy (polyethyleneglycol) (mPEG-PLGA-mPEG, PELGE) nanoparticles (PELGE-NP) containing mitoxantrone (DHAQ) as a model drug. PELGE copolymers with various molar ratios of lactic to glycolic acid and different molecular weights and various content mPEG were synthesized by ring-opening polymerization. mPEG with weight-average molecular weight (Mw) 2,000 or 5,000 was introduced as a hydrophilic segment into a hydrophobic PLGA. A double emulsion method with dextran70 as stabilizer in the external aqueous phase was used to prepare the nanoparticles. The drug entrapment efficiencies were more than 80% and the mean diameters of the nanoparticles were less than 200 nm. Various PELGE was studied as biodegradable drug carriers and there in vitro/in vivo release profiles were examined. It was found that drug loading, polymer molecular weight, copolymer composition and end group modifications were critical factors affecting the in vitro/in vivo release properties. The amount of drug released increased as the mPEG contents increased and the molar ratios of lactic acid decreased in vitro. The intravenous (i.v.) administration of mPEG-PLGA-mPEG nanoparticles of DHAQ in mice resulted in prolonged DHAQ residence in systemic blood circulation compared to the intravenous administration of PLGA nanoparticles.
Löw, Karin; Knobloch, Thomas; Wagner, Sylvia; Wiehe, Arno; Engel, Andrea; Langer, Klaus; von Briesen, Hagen
The second generation photosensitizer mTHPC was approved by the European Medicines Agency (EMA) for the palliative treatment of advanced head and neck cancer in October 2001. It is known that mTHPC possesses a significant phototoxicity against a variety of human cancer cells in vitro but also exhibits dark toxicity and can cause adverse effects (especially skin photosensitization). Due to its poor water solubility, the administration of hydrophobic photosensitizer still presents several difficulties. To overcome the administration problems, the use of nanoparticles as drug carrier systems is much investigated. Nanoparticles based on poly(lactic-co-glycolic acid) (PLGA) have been extensively studied as delivery systems into tumours due to their biocompatibility and biodegradability. The goal of this study was the comparison of free mTHPC and mTHPC-loaded PLGA nanoparticles concerning cytotoxicity and intracellular accumulation in human colon carcinoma cells (HT29). The nanoparticles delivered the photosensitizer to the colon carcinoma cells and enabled drug release without losing its activity. The cytotoxicity assays showed a time- and concentration-dependent decrease in cell proliferation and viability after illumination. However, first and foremost mTHPC lost its dark toxic effects using the PLGA nanoparticles as a drug carrier system. Therefore, PLGA nanoparticles are a promising drug carrier system for the hydrophobic photosensitizer mTHPC.
Kojima, Ryo; Yoshida, Takatsune; Tasaki, Hiroaki; Umejima, Hiroyuki; Maeda, Masashi; Higashi, Yasuyuki; Watanabe, Shunsuke; Oku, Naoto
The objective of this study was to elucidate the release and absorption mechanisms of tacrolimus loaded into microspheres composed of poly(lactic-co-glycolic acid) (PLGA) and/or polylactic acid (PLA). Tacrolimus-loaded microspheres were prepared by the o/w emulsion solvent evaporation method. The entrapment efficiency correlated with the molecular weight of PLGA, and the glass transition temperature of PLGA microspheres was not decreased by the addition of tacrolimus. These results indicate that intermolecular interaction between tacrolimus and the polymer would affect the entrapment of tacrolimus in the microspheres. Tacrolimus was released with weight loss of the microspheres, and the dominant release mechanism of tacrolimus was considered to be erosion of the polymer rather than diffusion of the drug. The whole-blood concentration of tacrolimus in rats was maintained for at least 2 weeks after a single subcutaneous administration of the microspheres. The pharmacokinetic profile of tacrolimus following subcutaneous administration was similar to that following intramuscular administration, suggesting that the release and dissolution of tacrolimus, rather than the absorption of the dissolved tacrolimus, were rate-limiting steps. Graft-survival time in a heart transplantation rat model was prolonged by the administration of tacrolimus-loaded microspheres. The microsphere formulation of tacrolimus would be expected to precisely control the blood concentration while maintaining the immunosuppressive effect of the drug.
Hamishehkar, Hamed; Emami, Jaber; Najafabadi, Abdolhossein Rouholamini; Gilani, Kambiz; Minaiyan, Mohsen; Mahdavi, Hamid; Nokhodchi, Ali
Biodegradable polymeric microspheres are ideal vehicles for controlled delivery applications of drugs, peptides and proteins. Amongst them, poly(lactic-co-glycolic acid) (PLGA) has generated enormous interest due to their favorable properties and also has been approved by FDA for drug delivery. Insulin-loaded PLGA microparticles were prepared by our developed single phase oil in oil (o/o) emulsion solvent evaporation technique. Insulin, a model protein, was successfully loaded into microparticles by changing experimental variables such as polymer molecular weight, polymer concentration, surfactant concentration and stirring speed in order to optimize process variables on drug encapsulation efficiency, release rates, size and size distribution. A 2(4) full factorial design was employed to evaluate systematically the combined effect of variables on responses. Scanning electron microscope (SEM) confirmed spherical shapes, smooth surface morphology and microsphere structure without aggregation. FTIR and DSC results showed drug-polymer interaction. The encapsulation efficiency of insulin was mainly influenced by surfactant concentration. Moreover, polymer concentration and polymer molecular weight affected burst release of drug and size characteristics of microspheres, respectively. It was concluded that using PLGA with higher molecular weight, high surfactant and polymer concentrations led to a more appropriate encapsulation efficiency of insulin with low burst effect and desirable release pattern.
Cappellano, Giuseppe; Woldetsadik, Abiy Demeke; Orilieri, Elisabetta; Shivakumar, Yogesh; Rizzi, Manuela; Carniato, Fabio; Gigliotti, Casimiro Luca; Boggio, Elena; Clemente, Nausicaa; Comi, Cristoforo; Dianzani, Chiara; Boldorini, Renzo; Chiocchetti, Annalisa; Renò, Filippo; Dianzani, Umberto
"Inverse vaccination" refers to antigen-specific tolerogenic immunization treatments that are capable of inhibiting autoimmune responses. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), initial trials using purified myelin antigens required repeated injections because of the rapid clearance of the antigens. This problem has been overcome by DNA-based vaccines encoding for myelin autoantigens alone or in combination with "adjuvant" molecules, such as interleukin (IL)-4 or IL-10, that support regulatory immune responses. Phase I and II clinical trials with myelin basic protein (MBP)-based DNA vaccines showed positive results in reducing magnetic resonance imaging (MRI)-measured lesions and inducing tolerance to myelin antigens in subsets of MS patients. However, DNA vaccination has potential risks that limit its use in humans. An alternative approach could be the use of protein-based inverse vaccines loaded in polymeric biodegradable lactic-glycolic acid (PLGA) nano/microparticles (NP) to obtain the sustained release of antigens and regulatory adjuvants. The aim of this work was to test the effectiveness of PLGA-NP loaded with the myelin oligodendrocyte glycoprotein (MOG)35-55 autoantigen and recombinant (r) IL-10 to inverse vaccinate mice with EAE. In vitro experiments showed that upon encapsulation in PLGA-NP, both MOG35-55 and rIL-10 were released for several weeks into the supernatant. PLGA-NP did not display cytotoxic or proinflammatory activity and were partially endocytosed by phagocytes. In vivo experiments showed that subcutaneous prophylactic and therapeutic inverse vaccination with PLGA-NP loaded with MOG35-55 and rIL-10 significantly ameliorated the course of EAE induced with MOG35-55 in C57BL/6 mice. Moreover, they decreased the histopathologic lesions in the central nervous tissue and the secretion of IL-17 and interferon (IFN)-γ induced by MOG35-55 in splenic T cells in vitro. These data suggest that
Gaspar, Vítor M; Moreira, André F; Costa, Elisabete C; Queiroz, João A; Sousa, Fani; Pichon, Chantal; Correia, Ilídio J
Drug-DNA combination therapies are receiving an ever growing focus due to their potential for improving cancer treatment. However, such approaches are still limited by the lack of multipurpose delivery systems that encapsulate drugs and condense DNA simultaneously. In this study, we describe the successful formulation of gas-generating pH-responsive D-α-tocopherol PEG succinate-poly(D,L-lactic-co-glycolic acid) (TPGS-PLGA) hollow microspheres loaded with both Doxorubicin (Dox) and minicircle DNA (mcDNA) nanoparticles as a strategy to co-deliver these therapeutics. For this study mcDNA vectors were chosen due to their increased therapeutic efficiency in comparison to standard plasmid DNA. The results demonstrate that TPGS-PLGA microcarriers can encapsulate Dox and chitosan nanoparticles completely condense mcDNA. The loading of mcDNA-nanoparticles into microspheres was confirmed by 3D confocal microscopy and co-localization analysis. The resulting TPGS-PLGA-Dox-mcDNA nanoparticle-in-microsphere hybrid carriers exhibit a well-defined spherical shape and neutral surface charge. Microcarriers incubation in acidic pH produced a gas-mediated Dox release, corroborating the microcarriers stimuli-responsive character. Also, the dual-loaded TPGS-PLGA particles achieved 5.2-fold higher cellular internalization in comparison with non-pegylated microspheres. This increased intracellular concentration resulted in a higher cytotoxic effect. Successful transgene expression was obtained after nanoparticle-mcDNA co-delivery in the microspheres. Overall these findings support the concept of using nanoparticle-microsphere multipart systems to achieve efficient co-delivery of various drug-mcDNA combinations.
Mao, Shirui; Xu, Jing; Cai, Cuifang; Germershaus, Oliver; Schaper, Andreas; Kissel, Thomas
Using fluorescein isothiocyanate labeled dextran (FITC-dextran 40, FD40) as a hydrophilic model compound, microspheres were prepared by a WOW double emulsion technique. Influence of process parameters on microsphere morphology and burst release of FD40 from PLGA microspheres was studied. Internal morphology of microspheres was investigated by stereological method via cryo-cutting technique and scanning electron microscopy (SEM). Drug distribution in microspheres was observed with confocal laser scanning microscopy (CLSM). Polymer nature (RG503 and RG503H) had significant influence on the micro-morphology of microspheres. Increase in continuous water phase volume (W2) led to increased surface porosity but decreased internal porosity. By increasing PVA concentration in the continuous phase from 0.1 to 1%, particle size changed marginally but burst release decreased from 12.2 to 5.9%. Internal porosity of microspheres decreased considerably with increasing polymer concentration. Increase in homogenization speed during the primary emulsion preparation led to decreased internal porosity. Burst release decreased with increasing drug loading but increased with drug molecular weight. Drug distribution in microspheres depended on preparation method. The porosity of microspheres decreased with time in the diffusion stage, but internal morphology had no influence on the release behavior in the bioerosion stage. In summary, surface porosity and internal morphology play a significant role in the release of hydrophilic macromolecules from biodegradable microspheres in the initial release phase characterized by pore diffusion.
Xu, Yuanyuan; Shen, Ming; Li, Yiming; Sun, Ying; Teng, Yanwei; Wang, Yi; Duan, Yourong
To get better chemotherapy efficacy, the optimal synergic effect of Paclitaxel (PTX) and Temozolomide (TMZ) on glioblastoma cells lines was investigated. A dual drug-loaded delivery system based on mPEG-PLGA nanoparticles (NPs) was developed to potentiate chemotherapy efficacy for glioblastoma. PTX/TMZ-NPs were prepared with double emulsification solvent evaporation method and exhibited a relatively uniform diameter of 206.3 ± 14.7 nm. The NPs showed sustained release character. Cytotoxicity assays showed the best synergistic effects were achieved when the weight ratios of PTX to TMZ were 1:5 and 1:100 on U87 and C6 cells, respectively. PTX/TMZ-NPs showed better inhibition effect to U87 and C6 cells than single drug NPs or free drugs mixture. PTX/TMZ-NPs (PTX: TMZ was 1:5(w/w)) significantly inhibited the tumor growth in the subcutaneous U87 mice model. These results indicate that coordinate administration of PTX and TMZ combined with NPs is an efficient method for glioblastoma.
Li, Yiming; Sun, Ying; Teng, Yanwei; Wang, Yi; Duan, Yourong
To get better chemotherapy efficacy, the optimal synergic effect of Paclitaxel (PTX) and Temozolomide (TMZ) on glioblastoma cells lines was investigated. A dual drug-loaded delivery system based on mPEG-PLGA nanoparticles (NPs) was developed to potentiate chemotherapy efficacy for glioblastoma. PTX/TMZ-NPs were prepared with double emulsification solvent evaporation method and exhibited a relatively uniform diameter of 206.3 ± 14.7 nm. The NPs showed sustained release character. Cytotoxicity assays showed the best synergistic effects were achieved when the weight ratios of PTX to TMZ were 1:5 and 1:100 on U87 and C6 cells, respectively. PTX/TMZ-NPs showed better inhibition effect to U87 and C6 cells than single drug NPs or free drugs mixture. PTX/TMZ-NPs (PTX: TMZ was 1:5(w/w)) significantly inhibited the tumor growth in the subcutaneous U87 mice model. These results indicate that coordinate administration of PTX and TMZ combined with NPs is an efficient method for glioblastoma. PMID:26956046
Chen, Yan; Zheng, Xue-Lian; Fang, Dai-Long; Yang, Yang; Zhang, Jin-Kun; Li, Hui-Li; Xu, Bei; Lei, Yi; Ren, Ke; Song, Xiang-Rong
Multidrug-resistant breast cancers have limited and ineffective clinical treatment options. This study aimed to develop PLGA nanoparticles containing a synergistic combination of vincristine and verapamil to achieve less toxicity and enhanced efficacy on multidrug-resistant breast cancers. The 1:250 molar ratio of VCR/VRP showed strong synergism with the reversal index of approximately 130 in the multidrug-resistant MCF-7/ADR cells compared to drug-sensitive MCF-7 cells. The lyophilized nanoparticles could get dispersed quickly with the similar size distribution, zeta potential and encapsulation efficiency to the pre-lyophilized nanoparticles suspension, and maintain the synergistic in vitro release ratio of drugs. The co-encapsulated nanoparticle formulation had lower toxicity than free vincristine/verapamil combinations according to the acute-toxicity test. Furthermore, the most effective tumor growth inhibition in the MCF-7/ADR human breast tumor xenograft was observed in the co-delivery nanoparticle formulation group in comparison with saline control, free vincristine, free vincristine/verapamil combinations and single-drug nanoparticle combinations. All the data demonstrated that PLGANPs simultaneously loaded with chemotherapeutic drug and chemosensitizer might be one of the most potential formulations in the treatment of multidrug-resistant breast cancer in clinic. PMID:24552875
Wang, Haiou; Jia, Yuntao; Hu, Wenjing; Jiang, Huiming; Zhang, Jingqing; Zhang, Liangke
This study prepared monomethoxy poly(ethylene glycol)-poly(lactide-co-glycolide) (mPEG-PLGA) nanoparticles simultaneously loaded with vincristine sulfate (Vin) and curcumin (Cur) via O/W emulsion solvent evaporation. Five independent processing parameters were systematically evaluated to enhance the entrapment of dual agents with different properties (i.e. Vin and Cur, which are the hydrophilic and hydrophobic, respectively) into mPEG-PLGA nanoparticles and to control the particle size. The approaches used to investigate the enhancement of drug entrapment efficiencies and control over the particle size included mPEG-PLGA concentration, polyvinyl alcohol (PVA) concentration, initial Vin/Cur content, dichloromethane-to-acetone volume ratio, and aqueous-to-organic phase volume ratio. The nanoparticles produced using the optimum formulation conditions had a particle size of 131.5 nm with a low polydispersity index of 0.047. The entrapment efficiencies were 63.52 ± 2.36% for Vin and 54.60 ± 2.46% for Cur (n = 3). The drug loadings were 1.06 ± 0.04% for Vin and 3.64 ± 0.16% for Cur (n = 3).
Qi, Feng; Wu, Jie; Fan, Qingze; He, Fan; Tian, Guifang; Yang, Tingyuan; Ma, Guanghui; Su, Zhiguo
Exenatide-loaded poly(d,l-lactic-co-glycolic acid) (PLGA) microspheres hold great potential as a drug delivery system to treat type 2 diabetes mellitus (T2DM) because they can overcome the shortcoming of exenatide's short half-life and realize sustained efficacy. However, conventional preparation methods often lead to microspheres with a broad size distribution, which in turn would cause poor preparation repeatability, drug efficacy and so forth. In this study, we used Shirasu Porous Glass (SPG) premix membrane emulsification technique characterized with high trans-membrane flux and size controllability to prepare uniform-sized PLGA microspheres. By optimizing trans-membrane pressure and PVA concentration in external aqueous phase, uniform-sized PLGA microspheres with large size (around 20μm) were successfully obtained. To achieve high encapsulation efficiency (EE) and improve in vitro release behavior, we have carefully examined the process parameters. Our results show that using ultrasonication to form primary emulsion, microspheres with high EE were easily obtained, but the rate of in vitro release was very slow. Instead, high EE and appropriate in vitro release were achieved when homogenization with optimized time and speed were employed. Besides, we also systematically investigated the effect of formulations on loading efficiency (LE) as well as the relationship between the resultant size of the microspheres and pore size of the membrane. Finally, through RP-HPLC and CD spectra analysis, we have demonstrated that the bio-stability of exenatide in microspheres was preserved during the preparation process.
Cañadas, Cristina; Alvarado, Helen; Calpena, Ana C; Silva, Amélia M; Souto, Eliana B; García, Maria L; Abrego, Guadalupe
Pranoprofen (PF) is a NSAID considered as a safe anti-inflammatory treatment for strabismus and/or cataract surgery. The drug has been formulated in poly (lactic/glycolic) acid (PLGA) nanoparticles (PF-F1NPs with cPF 1.5mg/mL, PF-F2NPs with cPF 1mg/mL) produced by solvent displacement technique and tested the in vitro cytotoxicity, ex vivo corneal permeation, in vivo ocular tolerance and in vivo anti-inflammatory efficacy of PF-F1NPs, PF-F2NPs, in comparison to eye drops conventional dosage form (Oftalar(®), PF 1mg/mL) and free drug solution (PF dissolved in PBS, 1.5mg/mL). The mean particle size of both formulations was around 350nm, with polydispersity index below 0.1, and a net negative charge of -7.41mV and -8.5mV for PF-F1NPs and PF-F2NPs, respectively. Y-79 human retinoblastoma cell line was used to evaluate the cytotoxicity of PF-F1NPs and PF-F2NPs, which were compared to blank NPs and free drug solution (PF dissolved in PBS, 1.5mg/mL). Concentrations up to 75μg/mL exhibited no toxicity to Y-79 cells, whereas at 150μg/mL a decrease of about 80% on the cell viability was observed after exposing the cells to PF-F1NPs. When treating the Y-79 cells with concentrations of PF-F2NPs between 1μg/mL to 100μg/mL, the cell viability was similar to control values after 24h and 48h of exposure. An ex vivo corneal permeation study was carried out in New Zealand rabbits. A very similar profile has been observed for the permeation of PF through the cornea when administered as eye drops and as free drug solution, which was kept much lower in comparison to PF-NPs formulations. The permeated amount of PF from the PF-F1NPs was slightly smaller than from PF-F2NPs, attributed to the increase of viscosity of the formulations with the increase of cPVA concentration. New Zealand white rabbits were also used to evaluate the irritancy of PF-F1NPs and PF-F2NPs, which demonstrated to be well-tolerated to the eye (i.e. the mean total score (MTS) was 0). PF-F2NPs exhibited the
Kanamycin sulphate (KS) is a Mycobacterium tuberculosis protein synthesis inhibitor. Due to its intense hydrophilicity, KS is cleared from the body within 8 h. KS has a very short plasma half-life (2.5 h). KS is used in high concentrations to reach the therapeutic levels in plasma, which results in serious nephrotoxicity/ototoxicity. To overcome aforementioned limitations, the current study aimed to develop KS loaded PLGA-Vitamin-E-TPGS nanoparticles (KS-PLGA-TPGS NPs), to act as an efficient carrier for controlled delivery of KS. To achieve a substantial extension in blood circulation, a combined design, affixation of polyethylene glycol (PEG) to KS-PLGA-TPGS NPs and adsorption of water-soluble chitosan (WSC) (cationic deacetylated chitin) to particle surface, was raised for surface modification of NPs. Surface modified NPs (KS-PEG-WSC NPs) were prepared to provide controlled delivery and circulate in the bloodstream for an extended period of time, thus minimizing dosing frequency. In vivo pharmacokinetics and in vivo biodistribution following intramuscular administration were investigated. NPs surface charge was close to neutral +3.61 mV and significantly affected by the WSC coating. KS-PEG-WSC NPs presented striking prolongation in blood circulation, reduced protein binding, and long drew-out the blood circulation half-life with resultant reduced kidney sequestration vis-à-vis KS-PLGA-TPGS NPs. The studies, therefore, indicate the successful formulation development of KS-PEG-WSC NPs with reduced frequency of dosing of KS indicating low incidence of nephrotoxicity/ototoxicity. PMID:28352475
Gentile, Piergiorgio; Nandagiri, Vijay Kumar; Daly, Jacqueline; Chiono, Valeria; Mattu, Clara; Tonda-Turo, Chiara; Ciardelli, Gianluca; Ramtoola, Zebunnissa
Localised controlled release of simvastatin from porous freeze-dried chitosan-gelatin (CH-G) scaffolds was investigated by incorporating simvastatin loaded poly-(dl-lactide-co-glycolide) acid (PLGA) microparticles (MSIMs) into the scaffolds. MSIMs at 10% w/w simvastatin loading were prepared using a single emulsion-solvent evaporation method. The MSIM optimal amount to be incorporated into the scaffolds was selected by analysing the effect of embedding increasing amounts of blank PLGA microparticles (BL-MPs) on the scaffold physical properties and on the in vitro cell viability using a clonal human osteoblastic cell line (hFOB). Increasing the BL-MP content from 0% to 33.3% w/w showed a significant decrease in swelling degree (from 1245±56% to 570±35%). Scaffold pore size and distribution changed significantly as a function of BL-MP loading. Compressive modulus of scaffolds increased with increasing BL-MP amount up to 16.6% w/w (23.0±1.0kPa). No significant difference in cell viability was observed with increasing BL-MP loading. Based on these results, a content of 16.6% w/w MSIM particles was incorporated successfully in CH-G scaffolds, showing a controlled localised release of simvastatin able to influence the hFOB cell proliferation and the osteoblastic differentiation after 11 days.
Alibolandi, Mona; Alabdollah, Fatemeh; Sadeghi, Fatemeh; Mohammadi, Marzieh; Abnous, Khalil; Ramezani, Mohammad; Hadizadeh, Farzin
Insulin is the first line therapy in type 1 diabetes and usually patients suffer from three or more daily insulin injections. It is obvious that patient compliance can be improved greatly if insulin could be formulated in an oral dosage form. In the current study, polymersomes based on amphiphilic copolymers of dextran (DEX)5000-poly(lactic-co-glycolic acid) (PLGA)13,000 and DEX25000-PLGA48000 were synthesized and used for the encapsulation of insulin. The polymersomes were prepared using a modified direct hydration method by blending an aqueous solution of insulin with DEX-PLGA copolymers at room temperature. The in vitro insulin release through the nanopolymersomal system was studied in HCl 0.1N (pH1.2) and phosphate buffered saline (pH7.4). The results demonstrated that the average insulin encapsulation efficiency was >90%. The in vitro release experiment demonstrated that while insulin release in the simulated gastric condition was negligible, a significant amount of insulin was released in the simulated intestinal condition. According to the results of a circular dichroism test, secondary and tertiary structures of the released insulin were identical to that of standard insulin. Permeability studies across MDCK cells showed that permeability levels after 240 min were 16.89 ± 0.39% with DEX5000-PLGA13000 and 9.34 ± 0.79% with DEX25000-PLGA48000, indicating a noticeable increase compared with free insulin. Significant hypoglycemic effects in the in vivo diabetic rat model revealed the efficacy of the DEX-PLGA-based polymersomes as oral insulin carriers. Thus, insulin-loaded, self-assembled DEX-PLGA polymersomes showed promising in vitro and in vivo efficiency and can be considered as a potential oral insulin carrier system.
Martín-Banderas, Lucía; Álvarez-Fuentes, Josefa; Durán-Lobato, Matilde; Prados, José; Melguizo, Consolación; Fernández-Arévalo, Mercedes; Holgado, Ma Ángeles
CB13 (1-Naphthalenyl[4-(pentyloxy)-1-naphthalenyl]methanone)-loaded poly(lactic-co-glycolic acid) nanoparticles (NPs) were produced by nanoprecipitation and tested for their in vitro release behavior and in vitro cytotoxicity assays. The effects of several formulation parameters such as polymer type, surfactant concentration, and initial drug amount were studied. NPs had a particle size 90–300 nm in diameter. Results obtained show that the main influence on particle size was the type of polymer employed during the particle production: the greater the hydrophobicity, the smaller the particle size. In terms of encapsulation efficiency (%), high values were achieved (∼68%–90%) for all formulations prepared due to the poor solubility of CB13 in the external aqueous phase. Moreover, an inverse relationship between release rate and NP size was found. On the other hand, low molecular weight and low lactide content resulted in a less hydrophobic polymer with increased rates of water absorption, hydrolysis, and erosion. NPs showed no cytotoxicity and may be considered to be appropriate for drug-delivery purposes. PMID:23209365
Paswan, Suresh K; Saini, T R
The emulsifiers in an exceedingly higher level are used in the preparation of drug loaded polymeric nanoparticles prepared by emulsification solvent evaporation method. This creates great problem to the formulator due to their serious toxicities when it is to be administered by parenteral route. The final product is therefore required to be freed from the used surfactants by the conventional purification techniques which is a cumbersome job. The solvent resistant stirred cell ultrafiltration unit (Millipore) was used in this study using polyethersulfone ultrafiltration membrane (Biomax®) having pore size of NMWL 300 KDa as the membrane filter. The purification efficiency of this technique was compared with the conventional centrifugation technique. The flow rate of ultrafiltration was optimized for removal of surfactant (polyvinyl alcohol) impurities to the acceptable levels in 1-3.5 h from the nanoparticle dispersion of tamoxifen prepared by emulsification solvent evaporation method. The present investigations demonstrate the application of solvent resistant stirred cell ultrafiltration technique for removal of toxic impurities of surfactant (PVA) from the polymeric drug nanoparticles (tamoxifen) prepared by emulsification solvent evaporation method. This technique offers added benefit of producing more concentrated nanoparticles dispersion without causing significant particle size growth which is observed in other purification techniques, e.g., centrifugation and ultracentrifugation.
Mustafa, Sanaul; Devi, V Kusum; Pai, Roopa S
Moxifloxacin (MOX) is a Mycobacterium tuberculosis DNA gyrase inhibitor. Due to its intense hydrophilicity, MOX is cleared from the body within 24 h and required for repetitive doses which may then result in hepatotoxicity and acquisition of MOX resistant-TB, related with its use. To overcome the aforementioned limitations, the current study aimed to develop PLGA nanoparticles (PLGA NPs), to act as an efficient carrier for controlled delivery of MOX. To achieve a substantial extension in blood circulation, a combined design, affixation of polyethylene glycol (PEG) to MOX-PLGA NPs and adsorption of water-soluble chitosan (WSC) (cationic deacetylated chitin) to particle surface, was rose for surface modification of NPs. Surface modified NPs (MOX-PEG-WSC NPs) were prepared to provide controlled delivery and circulate in the bloodstream for an extended period of time, thus minimizing dosing frequency. In vivo pharmacokinetic and in vivo biodistribution following oral administration were investigated. NP surface charge was closed to neutral +4.76 mV and significantly affected by the WSC coating. MOX-PEG-WSC NPs presented striking prolongation in blood circulation, reduced protein binding, and long-drawn-out the blood circulation half-life with resultant reduced liver sequestration vis-à-vis MOX-PLGA NPs. The studies, therefore, indicate the successful formulation development of MOX-PEG-WSC NPs that showed sustained release behavior from nanoparticles which indicates low frequency of dosing.
Seju, U; Kumar, A; Sawant, K K
Olanzapine (OZ) is a second-generation or atypical antipsychotic which selectively binds to central dopamine D₂ and serotonin (5-HT(2c)) receptors. It has poor bioavailability due to hepatic first-pass metabolism and low permeability into the brain due to efflux by P-glycoproteins. The present investigation aimed to prepare a nanoparticulate drug delivery system of OZ using poly(lactic-co-glycolic acid) (PLGA) for direct nose-to-brain delivery to provide brain targeting and sustained release. PLGA nanoparticles (NP) were prepared by the nanoprecipitation technique and characterized by entrapment efficiency, particle size, zeta potential, modulated temperature differential scanning calorimetry (MTDSC) and X-ray diffraction (XRD) studies. The NP were evaluated for in vitro release, ex vivo diffusion, toxicity and pharmacokinetic studies. The NP were 91.2±5.2 nm in diameter and had entrapment efficiency 68.91±2.31%. MTDSC studies indicated broadening of the drug peak and a shift in the polymer peak, possibly due to physical interaction or H-bonding between the carbonyl groups of PLGA and the NH groups of OZ, and also due to the plasticization effect of OZ on PLGA. XRD studies indicated a decrease in the crystallinity of OZ or amorphization. In vitro drug release showed a biphasic pattern with initial burst release and, later, sustained release (43.26±0.156% after 120 h), following the Fickian diffusion-based release mechanism. Ex vivo diffusion through sheep nasal mucosa showed 13.21±1.59% of drug diffusion in 210 min from NP. Histopathological study of sheep nasal mucosa showed no significant adverse effect of OZ-loaded NP. In vivo pharmacokinetic studies showed 6.35 and 10.86 times higher uptake of intranasally delivered NP than OZ solution delivered through intravenous (IV) and intranasal (IN) route, respectively. These results proved that OZ could be transported directly to the brain after IN delivery of PLGA NP, enhanced drug concentration in the brain and
Niu, Chengcheng; Wang, Zhigang; Lu, Guangming; Krupka, Tianyi M; Sun, Yang; You, Yufang; Song, Weixiang; Ran, Haitao; Li, Pan; Zheng, Yuanyi
Current strategies for tumor-induced sentinel lymph node detection and metastasis therapy have limitations. In this work, we co-encapsulated iron oxide nanoparticles and chemotherapeutic drug into poly(lactic-co-glycolic acid) (PLGA) microbubbles to form multifunctional polymer microbubbles (MPMBs) for both tumor lymph node imaging and therapy. Fe(3)O(4) nanoparticles and doxorubicin (DOX) co-encapsulated PLGA microbubbles were prepared and filled with perfluorocarbon gas. Enhancement of ultrasound (US)/magnetic resonance (MR) imaging and US triggered drug delivery were evaluated both in vitro and in vivo. The MPMBs exhibited characters like narrow size distribution and smooth surface with a mean diameter of 868.0 ± 68.73 nm. In addition, varying the concentration of Fe(3)O(4) nanoparticles in the bubbles did not significantly influence the DOX encapsulation efficiency or drug loading efficiency. Our in vitro results demonstrated that these MPMBs could enhance both US and MR imaging which was further validated in vivo showing that these MPMBs enhanced tumor lymph nodes signals. The anti-tumor effect of MPMBs mediated chemotherapy was assessed in vivo using end markers like tumor proliferation index, micro blood vessel density and micro lymphatic vessel density, which were shown consistently the lowest after the MPMBs plus sonication treatment compared to controls. In line with these findings, the tumor cell apoptotic index was found the largest after the MPMBs plus sonication treatment. In conclusion, we have successfully developed a doxorubicin loaded superparamagnetic PLGA-Iron Oxide multifunctional theranostic agent for dual-mode US/MR Imaging of lymph node, and for low frequency US triggered therapy of metastasis in lymph nodes, which might provide a strategy for the imaging and chemotherapy of primary tumor and their metastases.
Ruozi, Barbara; Belletti, Daniela; Sharma, Hari S; Sharma, Aruna; Muresanu, Dafin F; Mössler, Herbert; Forni, Flavio; Vandelli, Maria Angela; Tosi, Giovanni
Cerebrolysin is a peptide mixture able to ameliorate symptomatology and delay progression of neurological disorders such as Alzheimer's disease and dementia. The administration of this drug in humans presents several criticisms due to its short half-life, poor stability, and high doses needed to achieve the effect. This paper investigates the potential of polylactic-co-glycolide (PLGA) nanoparticles (NPs) as sustained release systems for iv administration of cerebrolysin in normal and brain injured rats. NPs were prepared by water-in-oil-in-water (w/o/w) double emulsion technique and characterized by light scattering for mean size and zeta potential and by scanning electron microscopy (SEM) for surface morphology. The NPs produced by double sonication under cooling at 60 W for 45 s, 12 mL of 1 % w:v of PVA, and 1:0.6 w:w drug/PLGA ratio (C-NPs4) displayed an adequate loading of drug (24 ± 1 mg/100 mg of NPs), zeta potential value (-13 mV), and average diameters (ranged from 250 to 330 nm) suitable to iv administration. SEM images suggested that cerebrolysin was molecularly dispersed into matricial systems and partially adhered to the NP surface. A biphasic release with an initial burst effect followed by sustained release over 24 h was observed. Long-term stability both at room and at low temperature of freeze-dried NPs was investigated. To gain deeper insight into NP stability after in vivo administration, the stability of the best NP formulation was also tested in serum. These PLGA NPs loaded with cerebrolysin were able to reduce brain pathology following traumatic brain injury. However, the size, the polydispersivity, and the surface properties of sample were significantly affected by the incubation time and the serum concentration.
Saadati, Roonak; Dadashzadeh, Simin
The purpose of this study was to investigate the effect of d-alpha tocopheryl polyethylene glycol 1000 succinate (TPGS) alone or in combination with other emulsifiers in the fabrication of etoposide-loaded PLGA-PEG nanoparticles for in vivo applications. Nanoparticles were prepared by nanoprecipitation or single-emulsion solvent evaporation method using TPGS alone or in combination with other surfactants. These nanoparticles were fully characterized by different techniques. For nanoprecipitation preparations, by adding 0.1% TPGS to polyvinyl alcohol in the aqueous phase, encapsulation efficiency markedly increased (up to 82%); moreover, drug release was readily controlled up to 3 days. Regarding emulsion solvent evaporation method, the highest encapsulation efficiency was obtained for nanoparticles emulsified with polyvinyl alcohol or TPGS; however, the burst release was high. When the combination of TPGS and polyvinyl alcohol was applied a marked increase in encapsulation efficiency (∼ 90%) was observed and the drug release was extended to more than one week. Pharmacokinetic measurements showed that the optimum formulation generated 14.4 times higher AUC and lasted 5.1 times longer when compared to free drug. Overall, using TPGS in combination with polyvinyl alcohol as an emulsifier in preparing etoposide loaded PLGA-PEG nanoparticles markedly increased the encapsulation efficiency, sustained drug release and resulted in nanoparticles with noticeable sustainable in vivo disposition. Copyright © 2014 Elsevier B.V. All rights reserved.
Lin, Xia; Yang, Shenshen; Gou, Jingxin; Zhao, Mingming; Zhang, Yu; Qi, Na; He, Haibing; Cai, Cuifang; Tang, Xing; Guo, Penghong
The purpose of this study was to develop an in situ forming SAIB (sucrose acetate isobutyrate)-PLGA (poly (d, lactide-co-glycolide)) mixture matrix depot for sustained release of risperidone. The factors affecting the risperidone release kinetics were investigated to obtain further insight into the drug release mechanisms. The burst release in vitro was significantly reduced (4.95%) by using DMSO as solvent. And, increasing the PLGA content from 2 to 10% w/w decreased the initial release from 6.95 to 1.05%. The initial release in vivo decreased with increasing PLGA content (2.0% w/w PLGA, C(max) = 1161.7 ± 550.2 ng ml(-1); 10% w/w PLGA, C(max) = 280.3 ± 98.5 ng ml(-1)). The persistence (AUC(4-20 days)) over 20 days increased from 76.8 ± 20.7 to 362.8 ± 75.0 ng d ml(-1) by inclusion of 10% PLGA compared with the PLGA-free depot. These results demonstrate that the SAIB-PLGA mixture matrix depot could be useful as a sustained delivery system for risperidone.
Cui, Fude; Shi, Kai; Zhang, Liqiang; Tao, Anjin; Kawashima, Yoshiaki
Biodegradable nanoparticles loaded with insulin-phospholipid complex were prepared by a novel reverse micelle-solvent evaporation method, in which soybean phosphatidylcholine (SPC) was employed to improve the liposolubility of insulin, and biodegradable polymers as carrier materials to control drug release. Solubilization study, IR and X-ray diffraction analysis were employed to prove the complex formation. The effects of key parameters such as polymer/SPC weight ratio, organic phase and polymer type on the properties of the nanoparticles were investigated. Spherical particles of 200 nm mean diameter and a narrow size distribution were obtained under optimal conditions. The drug entrapment efficiency was up to 90%. The in vitro drug release was characterized by an initial burst and subsequent delayed release in both pH 6.8 and pH 1.2 dissolution mediums. The specific modality of drug release, i.e., free or SPC-combined, was investigated in the aid of ultracentrifugation and ultrafiltration methods. The influence of polymer type on the drug release was also discussed. The pharmacological effects of the nanoparticles made of PLGA 50/50 (Av.Mw 9500) were further evaluated to confirm their potential suitability for oral delivery. Intragastric administration of the 20 IU/kg nanoparticles reduced fasting plasma glucose levels to 57.4% within the first 8 h of administration and this continued for 12 h. PK/PD analysis indicated that 7.7% of oral bioavailability relative to subcutaneous injection was obtained.
Pan, Qiyong; Li, Wenkai; Yuan, Xuefeng; Rakhmanov, Yeltay; Wang, Pengcheng; Lu, Rui; Mao, Zekai; Shang, Xiaobin; You, Hongbo
With the application of tissue engineering to tissue regeneration, additional new complexes have been made in response to the challenge of cartilage-injury repair. This study was performed to construct a rat precartilaginous stem cells-based scaffold of self-assembling peptides RADA16-I/PLGA-PLL (poly-L-lysine coated PLGA) as extracellular matrix loading the NLS-TAT as a peptide-based carrier for a plasmid DNA containing hTGFβ3. After composites were cultured for 1, 2, 3 and 4 weeks, respectively, the results showed that the levels of chondrogenic-related gene expression were higher in the experimental group with and hTGFβ3 gene by reverse transcription-polymerase chain reaction, and with higher histochemical and immunohistochemical expression. hTGFβ3 protein expression had increased at 4 weeks based on western blot analysis. The results of this study show that a complex may be a suitable scaffold for cartilage repair and offer a strategy for tissue regeneration through the use of tissue engineering.
Herran, E; Perez-Gonzalez, R; Igartua, M; Pedraz, J L; Carro, E; Hernandez, R M
During adult life, hippocampus is an important brain region involved in neurogenesis. The generation and cell death of newly generated neuronal cells in this region have critical roles in brain maintenance and alterations in these processes are seen in Alzheimer's disease (AD). For the purpose of carrying out a neuroregenerative strategy, we propose a novel approach based on the encapsulation of vascular endothelial growth factor (VEGF) in poly (lactic co-glycolic acid) (PLGA) biodegradable nanospheres (NS) administered by craniotomy to stimulate the proliferation of neuronal precursors in a transgenic mouse model of AD. VEGF loaded nanospheres were prepared by double emulsion solvent evaporation technique, obtaining 200 nm nanospheres with a biphasic release profile. After demonstrating their efficacy in the proliferation and differentiation of neuronal cell cultures, in vivo studies were carried out. 3 months after VEGF-NS were implanted directly into the cerebral cortex of APP/Ps1 mice, the determination of BrdU(+) cells in the whole hippocampal region and specifically in the dentate gyrus, demonstrated a significantly enhanced cellular proliferation in VEGF-NS treated group. These results were also confirmed showing an increased number of DCX(+) and NeuN(+) cells. Hence, PLGA-VEGF nanospheres may be a potential strategy to modulate proliferative neuronal progenitors in the hippocampal region, and therefore, provide new insight for future therapeutic approaches in AD.
Lin, Zhen-Yu; Duan, Zhi-Xia; Guo, Xiao-Dong; Li, Jing-Feng; Lu, Hong-Wei; Zheng, Qi-Xin; Quan, Da-Ping; Yang, Shu-Hua
BMP-2 is one of the most important growth factors of bone regeneration. Polylactide-co-glycolic acid (PLGA), which is used as a biodegradable scaffold for delivering therapeutic agents, has been intensively investigated. In previous studies, we synthesized a novel BMP-2-related peptide (designated P24) and found that it could enhance the osteoblastic differentiation of bone marrow stromal cells (BMSCs). The objective of this study was to construct a biomimetic composite by incorporating P24 into a modified PLGA-(PEG-ASP)n copolymer to promote bone formation. In vitro, our results demonstrated that PLGA-(PEG-ASP)n scaffolds were shown to be an efficient system for sustained release of P24. Significantly more BMSCs attached to the P24/PLGA-(PEG-ASP)n and PLGA-(PEG-ASP)n membranes than to PLGA, and the cells in the two groups subsequently proliferated more vigorously than those in the PLGA group. The expression of osteogenic markers in P24/PLGA-(PEG-ASP)n group was stronger than that in the PLGA-(PEG-ASP)n and PLGA groups. Radiographic and histological examination, Western blotting and RT-PCR showed that P24/PLGA-(PEG-ASP)n scaffold could induce more effective ectopic bone formation in vivo, as compared with PLGA-(PEG-ASP)n or gelatin sponge alone. It is concluded that the PLGA-(PEG-ASP)n copolymer is a good P24 carrier and can serve as a good scaffold for controlled release of P24. This novel P24/PLGA-(PEG-ASP)n composite promises to be an excellent biomaterial for inducing bone regeneration.
Mohammadian, Farideh; Pilehvar-Soltanahmadi, Yones; Mofarrah, Mohsen; Dastani-Habashi, Mehdi; Zarghami, Nosratollah
Chrysin were well-documented as having significant biological roles particularly cancer chemo-preventive activity. However, the poor water solubility of chrysin limited their bioavailability and biomedical applications. In this study, we encapsulate the chrysin into PLGA-PEG nanoparticles for local treatment. In regard to the amount of the drug load, IC50 was significant decreased in nanocapsulated chrysin in comparison with free chrysin. This was confirmed through decrease of miR-18a, miR-21, and miR-221 genes expression by real-time PCR. The results demonstrated that PLGA-PEG-chrysin complexes can be more effective than free chrysin. Therefore, PLGA-PEG can be a better nanocarrier for this kind of hydrophobic flavonoid.
Jannuzzi, Grasielle Pereira; Souza, Nicole de Araújo; Françoso, Kátia Sanches; Pereira, Roney Henrique; Santos, Raquel Possemozer; Kaihami, Gilberto Hideo; Almeida, José Roberto Fogaça de; Batista, Wagner Luiz; Amaral, André Corrêa; Maranhão, Andrea Queiroz; Almeida, Sandro Rogério de; Ferreira, Karen Spadari
Paracoccidioidomycosis (PCM) is a systemic mycosis with lymphatic dissemination that is caused by Paracoccidioides species. Treatment of PCM consists of chemotherapeutics such as itraconazole, trimethoprim, sulfamethoxazole or amphotericin B. However, several studies are aiming to develop therapeutic alternatives for the treatment of fungal infection using new molecules as adjuvants. The single-chain variable fragments (scFv) from an antibody that mimics the main fungal component incorporated within poly(lactide-co-glycolic) acid (PLGA) nanoparticles helped treat the fungal disease. After expressing the scFv in Picchia pastoris (P. pastoris), the recombinant molecules were coupled with PLGA, and the BALB/c mice were immunized before or after infection with yeast Paracoccidioides brasiliensis (P. brasiliensis). Our results showed decreased disease progression and decreased fungal burden. Taken together, our results showed an increased of IFN-γ and IL-12 cytokine production and an increased number of macrophages and dendritic cells in the pulmonary tissue of BALB/c mice treated with a high concentration of our molecule. Our data further confirm that the scFv plays an important role in the treatment of experimental PCM. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
Trombone, Ana Paula F; Silva, Celio L; Almeida, Luciana P; Rosada, Rogerio S; Lima, Karla M; Oliver, Constance; Jamur, Maria C; Coelho-Castelo, Arlete A M
This study aimed to demonstrate that microspheres, used as delivery vehicle of DNA-Hsp65/TDM [plasmid DNA encoding heat shock protein 65 (Hsp65) coencapsulated with trehalose dimycolate (TDM) into PLGA microspheres], are widely spread among several organs after intramuscular administration in BALB/c mice. In general, we showed that these particles were phagocytosed by antigen presenting cells, such as macrophages and dendritic cells. Besides, it was demonstrated herein that draining lymph node cells presented a significant increase in the number of cells expressing costimulatory molecules (CD80 and CD86) and MHC class II, and also that the administration of the DNA-Hsp65/TDM and vector/TDM formulations resulted in the up-regulation of CD80, CD86 and MHC class II expression when compared to control formulations (vector/TDM and empty). Regarding the intracellular trafficking we observed that following phagocytosis, the microspheres were not found in the late endosomes and/or lysosomes, until 15 days after internalization, and we suggest that these constructions were hydrolysed in early compartments. Overall, these data expand our knowledge on PLGA [poly (lactic-co-glycolic acid)] microspheres as gene carriers in vaccination strategies, as well as open perspectives for their potential use in clinical practice.
Mosafer, Jafar; Abnous, Khalil; Tafaghodi, Mohsen; Mokhtarzadeh, Ahad; Ramezani, Mohammad
A superparamagnetic iron oxide nanoparticles (SPIONs)/doxorubicin (Dox) co-loaded poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles targeted with AS1411 aptamer (Apt) against murine C26 colon carcinoma cells is successfully developed via a modified multiple emulsion solvent evaporation method for theranostic purposes. The mean size of SPIO/Dox-NPs (NPs) was 130nm with a narrow particle size distribution and Dox loading of 3.0%. The SPIO loading of 16.0% and acceptable magnetic properties are obtained and analyzed using thermogravimetric and vibration simple magnetometer analysis, respectively. The best release profile from NPs was observed in PBS at pH 7.4, in which very low burst release was observed. Nucleolin is a targeting ligand to facilitate anti-tumor delivery of AS1411-targeted NPs. The Apt conjugation to NPs (Apt-NPs) enhanced cellular uptake of Dox in C26 cancer cells. Apt-NPs enhance the cytotoxicity effect of Dox followed by a significantly higher tumor inhibition and prolonged animal survival in mice bearing C26 colon carcinoma xenografts. Furthermore, Apt-NPs enhance the contrast of magnetic resonance images in tumor site. Altogether, these Apt-NPs could be considered as a powerful tumor-targeted delivery system for their potential as dual therapeutic and diagnostic applications in cancers. Copyright © 2016 Elsevier B.V. All rights reserved.
Allahyari, Mojgan; Mohit, Elham
abstract Due to the excellent safety profile of poly (D,L-lactide-co-glycolide) (PLGA) particles in human, and their biodegradability, many studies have focused on the application of PLGA particles as a controlled-release vaccine delivery system. Antigenic proteins/peptides can be encapsulated into or adsorbed to the surface of PLGA particles. The gradual release of loaded antigens from PLGA particles is necessary for the induction of efficient immunity. Various factors can influence protein release rates from PLGA particles, which can be defined intrinsic features of the polymer, particle characteristics as well as protein and environmental related factors. The use of PLGA particles encapsulating antigens of different diseases such as hepatitis B, tuberculosis, chlamydia, malaria, leishmania, toxoplasma and allergy antigens will be described herein. The co-delivery of antigens and immunostimulants (IS) with PLGA particles can prevent the systemic adverse effects of immunopotentiators and activate both dendritic cells (DCs) and natural killer (NKs) cells, consequently enhancing the therapeutic efficacy of antigen-loaded PLGA particles. We will review co-delivery of different TLR ligands with antigens in various models, highlighting the specific strengths and weaknesses of the system. Strategies to enhance the immunotherapeutic effect of DC-based vaccine using PLGA particles can be designed to target DCs by functionalized PLGA particle encapsulating siRNAs of suppressive gene, and disease specific antigens. Finally, specific examples of cellular targeting where decorating the surface of PLGA particles target orally administrated vaccine to M-cells will be highlighted. PMID:26513024
Mishra, Deepa; Kang, Han Chang; Cho, Hana; Bae, You Han
This study investigates the potential of dexamethasone (Dex) to enhance the nuclear accumulation and subsequent gene expression of plasmid DNA (pDNA) delivered using a charged polymeric micelle-based gene delivery system. (PLGA)n -b-bPEI25kDa block copolymers are synthesized and used to prepare Dex-loaded cationic micelles (DexCM). After preparing DexCM/pDNA complexes, bPEI1.8kDa is coated on the complexes using a Layer-by-Layer (LbL) technique to construct DexCM/pDNA/bPEI1.8kDa complexes (i.e., LbL-DexCM polyplexes) that are 100-180 nm in diameter and have a zeta potential of 30-40 mV. In MCF7 cells, LbL-DexCM polyplexes cause 3-13-fold higher transfection efficiencies compared to LbL-CM polyplexes and show negligible cytotoxicity. LbL-DexCM3 polyplexes induce much higher nuclear delivery of pDNA compared to LbL-CM3 polyplexes. These results suggest that Dex-loaded polyplexes could be used in gene and drug delivery applications to increase nuclear accumulation of therapeutic payloads, further leading to a decrease in the dose of the drug and gene necessary to achieve equivalent therapeutic effects.
Castellanos, Ingrid J; Flores, Giselle; Griebenow, Kai
The potential of cyclodextrins to stabilize alpha-chymotrypsin upon encapsulation in Poly(lactic-co-glycolic) acid (PLGA) microspheres using a solid-in-oil-in-water (s/o/w) technique was investigated. Two cyclodextrins, hydroxyl-propyl-beta-cyclodextrin (HPbetaCD) and methyl-beta-cyclodextrin (MbetaCD), one insoluble and the other soluble in methylene chloride, were used. The results demonstrate that HPbetaCD failed to stabilize alpha-chymotrypsin upon encapsulation. Specifically, 19% of the protein was aggregated and the specific activity of the enzyme was reduced to ca. 50% of that prior to encapsulation. In contrast, MbetaCD significantly decreased the formation of aggregates to 3% and the retained specific activity of the enzyme was approximately 90%. The co-lyophilization of alpha-chymotrypsin with MbetaCD prior to encapsulation was a requisite to preserve the protein stability in microspheres. Furthermore, MbetaCD prevented the loss of protein during the preparation of microspheres and the encapsulation efficiency was improved to 90%. Release experiments showed the use of MbetaCD modified the release profile: the burst release decreased from 54% (in the absence of the excipient) to 36%. The results suggest that MbetaCD might be a suitable excipient to improve protein stability in s/o/w encapsulation procedures.
Narayanan, Sreeja; Pavithran, Maya; Viswanath, Aiswarya; Narayanan, Dhanya; Mohan, Chandini C; Manzoor, K; Menon, Deepthy
The present study reports an engineered poly-l-lactide-co-glycolic acid (PLGA)-casein polymer-protein hybrid nanocarrier 190±12nm in size entrapping a combination of chemically distinct (hydrophobic/hydrophilic) model drugs. A simple emulsion-precipitation route was adopted to prepare nearly monodispersed nanoparticles with distinct core/shell morphology entrapping paclitaxel (Ptx) in the core and epigallocatechin gallate (EGCG) in the shell, with the intention of providing a sequential and sustained release of these drugs. The idea was that an early release of EGCG would substantially increase the sensitivity of Ptx to cancer, thereby providing improved therapeutics at lower concentrations, with less toxicity. The hemo- and immunocompatibility of the core/shell nanomedicine was established in this study. The core/shell nanoparticles injected via the tail vein in Sprague-Dawley rats did not reveal any organ toxicity as was evident from histopathological evaluations of the major organs. In vivo pharmacokinetic studies in rats by high-performance liquid chromatography confirmed a sustained and sequential release of both the drugs in plasma, indicating prolonged circulation of the nanomedicine and enhanced availability of the drugs when compared to the bare drugs. Overall, the polymer-protein multilayered nanoparticles proved to be a promising platform for nanopolypharmaceutics. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Jain, Sunil K; Haider, Tanweer; Kumar, Amrish; Jain, Akhlesh
Helicobacter pylori infection remains challenging as it mainly colonized beneath the deep gastric mucosa and adheres to epithelial cells of the stomach. Concanavalin-A (Con-A)-conjugated gastro-retentive poly (lactic-co-glycolic acid) (PLGA) nanoparticles of acetohydroxamic acid (AHA) and clarithromycin (CLR) were prepared and evaluated under in vitro conditions. Solvent evaporation method was employed for preparation of nanoparticles and characterized for particle size distribution, surface morphology, percent drug entrapment, and in vitro drug release in simulated gastric fluid. Optimized nanoparticles were conjugated with Con-A and further characterized for Con-A conjugation efficiency and mucoadhesion and tested for in vitro anti-H. pylori activity. The conjugation with Con-A further sustained the drug release over a period of 8 h when compared to non-conjugated nanoparticles of AHA and CLR. In vitro anti H. pylori study confirmed that Con-A-conjugated nanoparticles containing both drugs, i.e., CLR and AHA, had shown maximum zone of inhibition compared to other formulations. In a nut shell, results suggest that the developed systems could be used for better therapeutic activity against H. pylori infection.
Zhai, Peng; Chen, X B; Schreyer, David J
Poly(lactic-co-glycolic acid) (PLGA) microspheres and PLGA/alginate composite microspheres were prepared by a novel double emulsion and solvent evaporation technique and loaded with bovine serum albumin (BSA) or rabbit anti-laminin antibody protein. The addition of alginate and the use of a surfactant during microsphere preparation increased the encapsulation efficiency and reduced the initial burst release of hydrophilic BSA. Confocal laser scanning microcopy (CLSM) of BSA-loaded PLGA/alginate composite microspheres showed that PLGA, alginate, and BSA were distributed throughout the depths of microspheres; no core/shell structure was observed. Scanning electron microscopy revealed that PLGA microspheres erode and degrade more quickly than PLGA/alginate composite microspheres. When loaded with anti-laminin antibody, the function of released antibody was well preserved in both PLGA and PLGA/alginate composite microspheres. The biocompatibility of PLGA and PLGA/alginate microspheres were examined using four types of cultured cell lines, representing different tissue types. Cell survival was variably affected by the inclusion of alginate in composite microspheres, possibly due to the sensitivity of different cell types to excess calcium that may be released from the calcium cross-linked alginate.
Ansari, Mohammad Javed; Anwer, Md Khalid; Jamil, Shahid; Al-Shdefat, Ramadan; Ali, Bahaa E; Ahmad, Mohammad Muqtader; Ansari, Mohammad Nazam
Insulin is a hormone used in the treatment of diabetes mellitus. Multiple injections of insulin every day may causes pain, allergic reactions at injection site, which lead to low patient compliance. The aim of this work was to develop and evaluate an efficient solid lipid nanoparticle (SLN) carrier for oral delivery of insulin. SLNs were prepared by double emulsion solvent evaporation (w/o/w) technique, employing glyceryltrimyristate (Dynasan 114) as lipid phase and soy lecithin and polyvinyl alcohol as primary and secondary emulsifier, respectively, and evaluated in vitro for particle size, polydispersity index (PDI) and drug entrapment. Among the eight different developed formulae (F1-F8), F7 showed an average particle size (99 nm), PDI (0.021), high entrapment of drug (56.5%). The optimized formulation (F7) was further evaluated by FT-IR, DSC, XRD, in vitro release, permeation, stability, bioavailability and pharmacological studies. Insulin-loaded SLNs showed better protection from gastrointestinal environment as evident from the relative bioavailability, which was enhanced five times as compared to the insulin solution. A significant enhancement of relative bioavailability of insulin was observed, i.e. approximately five times of pure insulin solution when loaded in SLN (8.26% versus 1.7% only).
Ghorbani, Farnaz; Nojehdehian, Hanieh; Zamanian, Ali
Hydroxyapatite (HA)-gelatin scaffolds incorporated with dexamethasone-loaded polylactic-co-glycolic acid (PLGA) microspheres were synthesized by freeze casting technique. Scanning electron microscopy (SEM) micrographs demonstrated a unidirectional microstructure and a decrease in the pore size as a function of temperature gradient. Higher amounts of HA resulted in a decrease in the pore size. According to the results, at lower cooling rates, the formation of a lamellar structure decreased the mechanical strength, but at the same time, enhanced the swelling ratio, biodegradation rate and drug release level. On the other hand, higher weight ratios of HA increased the compressive strength, and reduced the swelling ratio, biodegradation rate and drug release level. The results obtained by furrier transform infrared spectroscopy (FTIR) and bioactivity analysis illustrated that the interactions of the materials support the apatite formation in the simulated body fluid (SBF) solution. Based on the obtained results, the synthesized composite scaffolds have the necessary mechanical and physicochemical features to support the regeneration of defects and to maintain their stability during the neo-tissue formation. Copyright © 2016 Elsevier B.V. All rights reserved.
Li, Peng-Li; Li, Chun-Xia; Xue, Yi-Ting; Li, Hai-Hua; Liu, Hong-Bing; He, Xiao-Xi; Yu, Guang-Li; Guan, Hua-Shi
This study was aimed at developing a sensitive and selective HPLC method with postcolumn fluorescence derivatization for the detection of propylene glycol alginate sodium sulfate (PSS) in rat plasma. Plasma samples were prepared by a simple and fast ultrafiltration method. PSS was extracted from rat plasma with d-glucuronic acid as internal standard. Isocratic chromatographic separation was performed on a TSKgel G2500 PWxL column with the mobile phase of 0.1 M sodium sulfate at a flow rate of 0.5 mL/min. Analyte detection was achieved by fluorescence detection (FLD) at 250 nm (excitation) and 435 nm (emission) using guanidine hydrochloride as postcolumn derivatizing reagent in an alkaline medium at 120 °C. The calibration curve was linear over a concentration range of 1–500 μg/mL, and the lower limit of detection (LLOD) was found to be 250 ng/mL. This validated method was applied successfully to the pharmacokinetic study of PSS and PSS-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (PSS-NP) in rat plasma after a single intravenous (PSS only) and oral administration (PSS and PSS-NP). Significant differences in the main pharmacokinetic parameters of PSS and PSS-NP were observed. The relative bioavailability of PSS-NP was 190.10% compared with PSS which shows that PSS-NP can improve oral bioavailability. PMID:23549283
Li, Peng-Li; Li, Chun-Xia; Xue, Yi-Ting; Li, Hai-Hua; Liu, Hong-Bing; He, Xiao-Xi; Yu, Guang-Li; Guan, Hua-Shi
This study was aimed at developing a sensitive and selective HPLC method with postcolumn fluorescence derivatization for the detection of propylene glycol alginate sodium sulfate (PSS) in rat plasma. Plasma samples were prepared by a simple and fast ultrafiltration method. PSS was extracted from rat plasma with D-glucuronic acid as internal standard. Isocratic chromatographic separation was performed on a TSKgel G2500 PWxL column with the mobile phase of 0.1 M sodium sulfate at a flow rate of 0.5 mL/min. Analyte detection was achieved by fluorescence detection (FLD) at 250 nm (excitation) and 435 nm (emission) using guanidine hydrochloride as postcolumn derivatizing reagent in an alkaline medium at 120 °C. The calibration curve was linear over a concentration range of 1-500 μg/mL, and the lower limit of detection (LLOD) was found to be 250 ng/mL. This validated method was applied successfully to the pharmacokinetic study of PSS and PSS-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles (PSS-NP) in rat plasma after a single intravenous (PSS only) and oral administration (PSS and PSS-NP). Significant differences in the main pharmacokinetic parameters of PSS and PSS-NP were observed. The relative bioavailability of PSS-NP was 190.10% compared with PSS which shows that PSS-NP can improve oral bioavailability.
Warsi, Musarrat H; Anwar, Mohammed; Garg, Vaidehi; Jain, Gaurav K; Talegaonkar, Sushama; Ahmad, Farhan J; Khar, Roop K
Poor drug penetration and rapid clearance after topical instillation of a drug formulation into the eyes are the major causes for the lower ocular bioavailability from conventional eye drops. Along with this, poor encapsulation efficiency of hydrophilic drug in polymeric nanoparticles remains a major formulation challenge. Taking this perspective into consideration, dorzolamide (DZ)-loaded PLGA nanoparticles were developed employing two different emulsifiers (PVA and vitamin E TPGS) and the effects of various formulation and process variables on particle size and encapsulation efficiency were assessed. Nanoparticles emulsified with vitamin E TPGS (DZ-T-NPs) were found to possess enhanced drug encapsulation (59.8±6.1%) as compared to those developed with PVA as emulsifier (DZ-P-NPs). Transcorneal permeation study revealed a significant enhancement in permeation (1.8-2.5 fold) as compared to solution. In addition, ex vivo biodistribution study showed a higher concentration of drug in the aqueous humour (1.5-2.3 fold). Histological and IR-camera studies proved the non-irritant potential of the formulations. Pharmacoscintigraphic studies revealed the reduced corneal clearance, as well as naso-lachrymal drainage in comparison to drug solution. Furthermore, efficacy study revealed that DZ-P-NPs and DZ-T-NPs significantly reduced the intraocular pressure by 22.81% and 29.12%, respectively, after a single topical instillation into the eye. Copyright © 2014 Elsevier B.V. All rights reserved.
Manosroi, Aranya; Tangjai, Theeraphong; Sutthiwanjampa, Chanutchamon; Manosroi, Worapaka; Werner, Rolf G; Götz, Friedrich; Sainakham, Mathukorn; Manosroi, Jiradej
This study aimed to investigate the synergistic effect of trans-activator of transcription (Tat) and niosomes for the improvement of hypoglycemic activity of orally delivered human insulin. The elastic anionic niosomes composing of Tween 61/cholesterol/dicetyl phosphate/sodium cholate at 1:1:0.05:0.02 molar ratio loaded with insulin-Tat mixture (1:3 molar ratio) was prepared. Deformability of the elastic anionic niosomes decreased after loaded with the mixture of 1.35 times. For the in vitro release, the insulin (T10 = 4 h) loaded in the elastic anionic niosomes indicated the slower release rate than insulin in the mixture (T10 = 3 h) loaded in niosomes. At room temperature (30 ± 2 °C), the mixture loaded in elastic anionic niosomes was more chemical stable than the free mixture of 1.3, 1.4 and 1.7 times after stored for 4, 8 and 12 weeks, respectively. Oral administration in the alloxan-induced diabetic mice of the mixture loaded in elastic anionic niosomes with the insulin doses at 25, 50 and 100 IU/kg body weight indicated significant hypoglycemic activity with the percentage fasting blood glucose reduction of 1.95, 2.10 and 2.10 folds of the subcutaneous insulin injection at 12 h, respectively. This study has demonstrated the synergistic benefits of Tat and elastic anionic niosomes for improving the hypoglycemic activity of the orally delivered human insulin as well as the stability enhancement of human insulin when stored at high temperature. The results from this study can be further developed as an effective oral insulin delivery.
Shim, Jin-Hyung; Yoon, Min-Chul; Jeong, Chang-Mo; Jang, Jinah; Jeong, Sung-In; Cho, Dong-Woo; Huh, Jung-Bo
We successfully fabricated a three-dimensional (3D) printing-based PCL/PLGA/β-TCP guided bone regeneration (GBR) membrane that slowly released rhBMP-2. To impregnate the GBR membrane with intact rhBMP-2, collagen solution encapsulating rhBMP-2 (5 µg ml(-1)) was infused into pores of a PCL/PLGA/β-TCP membrane constructed using a 3D printing system with four dispensing heads. In a release profile test, sustained release of rhBMP-2 was observed for up to 28 d. To investigate the efficacy of the GBR membrane on bone regeneration, PCL/PLGA/β-TCP membranes with or without rhBMP-2 were implanted in an 8 mm calvaria defect of rabbits. Bone formation was evaluated at weeks 4 and 8 histologically and histomorphometrically. A space making ability of the GBR membrane was successfully maintained in both groups, and significantly more new bone was formed at post-implantation weeks 4 and 8 by rhBMP-2 loaded GBR membranes. Interestingly, implantation with rhBMP-2 loaded GBR membranes led to almost entire healing of calvaria defects within 8 weeks.
Xing, Lingxi; Shi, Qiusheng; Zheng, Kailiang; Shen, Ming; Ma, Jing; Li, Fan; Liu, Yang; Lin, Lizhou; Tu, Wenzhi; Duan, Yourong; Du, Lianfang
Pancreatic cancer, one of the most lethal human malignancies with dismal prognosis, is refractory to existing radio-chemotherapeutic treatment modalities. There is a critical unmet need to develop effective approaches, especially for targeted pancreatic cancer drug delivery. Targeted and drug-loaded nanoparticles (NPs) combined with ultrasound-mediated microbubble destruction (UMMD) have been shown to significantly increase the cellular uptake in vitro and drug retention in vivo, suggesting a promising strategy for cancer therapy. In this study, we synthesized pancreatic cancer-targeting organic NPs that were modified with anti CA19-9 antibody and encapsulated paclitaxol (PTX). The three-block copolymer methoxy polyethylene glycol-polylacticco-glycolic acid-polylysine (mPEG-PLGA-PLL) constituted the skeleton of the NPs. We speculated that the PTX-NPs-anti CA19-9 would circulate long-term in vivo, "actively target" pancreatic cancer cells, and sustainably release the loaded PTX while UMMD would "passively target" the irradiated tumor and effectively increase the permeability of cell membrane and capillary gaps. Our results demonstrated that the combination of PTX-NPs-anti CA19-9 with UMMD achieved a low IC50, significant cell cycle arrest, and cell apoptosis in vitro. In mouse pancreatic tumor xenografts, the combined application of PTX-NP-anti CA19-9 NPs with UMMD attained the highest tumor inhibition rate, promoted the pharmacokinetic profile by increasing AUC, t1/2, and mean residence time (MRT), and decreased clearance. Consequently, the survival of the tumor-bearing nude mice was prolonged without obvious toxicity. The dynamic change in cellular uptake, targeted real-time imaging, and the concentration of PTX in the plasma and tumor were all closely associated with the treatment efficacy both in vitro and in vivo. Our study suggests that PTX-NP-anti CA19-9 NPs combined with UMMD is a promising strategy for the treatment of pancreatic cancer.
Xing, Lingxi; Shi, Qiusheng; Zheng, Kailiang; Shen, Ming; Ma, Jing; Li, Fan; Liu, Yang; Lin, Lizhou; Tu, Wenzhi; Duan, Yourong; Du, Lianfang
Pancreatic cancer, one of the most lethal human malignancies with dismal prognosis, is refractory to existing radio-chemotherapeutic treatment modalities. There is a critical unmet need to develop effective approaches, especially for targeted pancreatic cancer drug delivery. Targeted and drug-loaded nanoparticles (NPs) combined with ultrasound-mediated microbubble destruction (UMMD) have been shown to significantly increase the cellular uptake in vitro and drug retention in vivo, suggesting a promising strategy for cancer therapy. In this study, we synthesized pancreatic cancer-targeting organic NPs that were modified with anti CA19-9 antibody and encapsulated paclitaxol (PTX). The three-block copolymer methoxy polyethylene glycol-polylacticco-glycolic acid-polylysine (mPEG-PLGA-PLL) constituted the skeleton of the NPs. We speculated that the PTX-NPs-anti CA19-9 would circulate long-term in vivo, "actively target" pancreatic cancer cells, and sustainably release the loaded PTX while UMMD would "passively target" the irradiated tumor and effectively increase the permeability of cell membrane and capillary gaps. Our results demonstrated that the combination of PTX-NPs-anti CA19-9 with UMMD achieved a low IC50, significant cell cycle arrest, and cell apoptosis in vitro. In mouse pancreatic tumor xenografts, the combined application of PTX-NP-anti CA19-9 NPs with UMMD attained the highest tumor inhibition rate, promoted the pharmacokinetic profile by increasing AUC, t1/2, and mean residence time (MRT), and decreased clearance. Consequently, the survival of the tumor-bearing nude mice was prolonged without obvious toxicity. The dynamic change in cellular uptake, targeted real-time imaging, and the concentration of PTX in the plasma and tumor were all closely associated with the treatment efficacy both in vitro and in vivo. Our study suggests that PTX-NP-anti CA19-9 NPs combined with UMMD is a promising strategy for the treatment of pancreatic cancer. PMID:27446491
DU, Jing; Sun, Ying; Li, Feng-Hua; DU, Lian-Fang; Duan, You-Rong
We investigated the efficacy and safety of ultrasound (US)-targeted microbubble (MB) destruction (UTMD)-enhanced delivery of monomethoxypoly(ethylene glycol)-poly(lactic-co-glycolic acid)-poly-L-lysine (mPEG-PLGA-PLL) nanoparticles (NPs) loading Cy3-labelled platelet-derived growth factor BB (PDGF-BB) siRNA to rat retina in vivo. Eighty Wistar rats were divided into five groups (G). The right eyes, respectively, received an intravitreal injection as follows: normal saline (NS) (G1), NPs and NS (G2), NPs and MBs (G3), NPs and NS (G4) and NPs and MBs (G5). In G4 and G5, the eyes were exposed to US for 5 mins. Twenty-four hours after transfection, the uptake and distribution of Cy3-labelled siRNA in rat retina were observed by fluorescent microscope. The percentage of Cy3- labelled siRNA-positive cells was evaluated by flow cytometer. The levels of PDGF-BB mRNA in retinal pigment epithelium (RPE) cells and secreted PDGF-BB proteins were also measured. Hematoxylin and eosin staining and frozen sections were used to observe tissue damage. Our results showed that the number of Cy3-labelled siRNApositive cells in G5 was significantly higher than those of the other groups (P less than 0.05 for all comparisons). The maximum efficiency of siRNA uptake in neural retina was 18.22 +/_ 1.67%. In G4 and G5, a small number of Cy3- labelled siRNA-positive cells were also detected in the pigmented cell layer of the retina. NPs loading siRNA delivered with UTMD could more effectively down-regulate the mRNA and protein expression of PDGF-BB than NPs plus US (P=0.014 and P=0.007, respectively). Histology showed no evident tissue damage after UTMDmediated NPs loading siRNA transfection. UTMD could be used safely to enhance the delivery of mPEG-PLGAPLL NPs loading siRNA into rat retina.
Bozzetto, L; Giorgini, M; Alderisio, A; Costagliola, L; Giacco, A; Riccardi, G; Rivellese, A A; Annuzzi, G
To evaluate feasibility and effectiveness on short-term blood glucose control of using glycaemic load counting (GLC) versus carbohydrate counting (CC) for prandial insulin dosing in patients with type 1 diabetes (T1D). Nine T1D patients on insulin pump, aged 26-58 years, HbA1c 7.7 ± 0.8 % (61 ± 8.7 mmol/mol), participated in this real-life setting study. By a crossover design, patients were randomised to calculate their pre-meal insulin dose based on the insulin/glycaemic load ratio (GLC period) or the insulin/carbohydrate ratio (CC period) for 1 week, shifting to the alternate method for the next week, when participants duplicated their first week food plan. Over either week, a blind subcutaneous continuous glucose monitoring was performed, and a 7-day food record was filled in. Total daily insulin doses (45 ± 10 vs. 44 ± 9 I.U.; M ± SD, p = 0.386) and basal infusion (26 ± 7 vs. 26 ± 8 I.U., p = 0.516) were not different during GLC and CC periods, respectively. However, the range of insulin doses (difference between highest and lowest insulin dose) was wider during GLC, with statistical significance at dinner (8.4 ± 6.2 vs. 6.0 ± 3.9 I.U., p = 0.041). Blood glucose iAUC after lunch was lower, albeit not significantly, during GLC than CC period (0.6 ± 8.6 vs. 3.4 ± 8.2 mmol/l∙3 h, p = 0.059). Postprandial glucose variability, evaluated as the maximal amplitude after meal (highest minus lowest glucose value), was significantly lower during GLC than CC period at lunch (4.22 ± 0.28 vs. 5.47 ± 0.39 mmol/l, p = 0.002) and dinner (3.89 ± 0.33 vs. 4.89 ± 0.33, p = 0.026). Calculating prandial insulin bolus based on glycaemic load counting is feasible in a real-life setting and may improve postprandial glucose control in people with T1D.
Fornaguera, C.; Feiner-Gracia, N.; Calderó, G.; García-Celma, M. J.; Solans, C.
Polymeric nanoparticles could be promising drug delivery systems to treat neurodegenerative diseases. Among the various methods of nanoparticle preparation, nano-emulsion templating was used in the present study to prepare galantamine-loaded nano-emulsions by a low-energy emulsification method followed by solvent evaporation to obtain galantamine-loaded polymeric nanoparticles. This approach was found to be suitable because biocompatible, biodegradable and safe nanoparticles with appropriate features (hydrodynamic radii around 20 nm, negative surface charge and stability higher than 3 months) for their intravenous administration were obtained. Encapsulation efficiencies higher than 90 wt% were obtained with a sustained drug release profile as compared to that from aqueous and micellar solutions. The enzymatic activity of the drug was maintained at 80% after its encapsulation into nanoparticles that were non-cytotoxic at the required therapeutic concentration. Therefore, novel galantamine-loaded polymeric nanoparticles have been designed for the first time using the nano-emulsification approach and showed the appropriate features to become advanced drug delivery systems to treat neurodegenerative diseases.Polymeric nanoparticles could be promising drug delivery systems to treat neurodegenerative diseases. Among the various methods of nanoparticle preparation, nano-emulsion templating was used in the present study to prepare galantamine-loaded nano-emulsions by a low-energy emulsification method followed by solvent evaporation to obtain galantamine-loaded polymeric nanoparticles. This approach was found to be suitable because biocompatible, biodegradable and safe nanoparticles with appropriate features (hydrodynamic radii around 20 nm, negative surface charge and stability higher than 3 months) for their intravenous administration were obtained. Encapsulation efficiencies higher than 90 wt% were obtained with a sustained drug release profile as compared to that from
Duvvuri, Sridhar; Janoria, Kumar Gaurav; Mitra, Ashim K
The purpose of this work is to develop empirical equations for describing the in vitro ganciclovir (GCV) release from PLGA microspheres and also to develop and characterize a formulation containing GCV loaded PLGA microspheres dispersed in thermogelling PLGA-PEG-PLGA polymer gel. Effect of polymer chain length and polymer blending on GCV entrapment and release from PLGA microspheres is also examined. PLGA microspheres of GCV were prepared from two polymers PLGA 6535 (d,l-lactide:glycolideColon, two colons65:35, Mw=45,000-75,000 Da) and Resomer RG 502H (d,l-lactide:glycolideColon, two colons50:50, Mw=8000 Da) and a 3:1 mixture. PLGA-PEG-PLGA polymer was synthesized and characterized. In vitro GCV release studies were conducted with microspheres and microspheres dispersed in 23% w/v PLGA-PEG-PLGA solution. Polymer blended microspheres entrap more GCV (72.67+/-2.49%) than both PLGA 6535 (51.37+/-2.7%) and Resomer RG 502H (47.13+/-1.13%) microspheres. In vitro drug release data was fit to sigmoid equations and release parameters were estimated by nonlinear regression analysis. These equations effectively describe three different phases in GCV release from PLGA microspheres, initial diffusion, matrix hydration and degradation. The amount of drug release during the initial phase decreased for the blend microspheres indicating efficient packing between the PLGA 6535 and Resomer RG 502H in the microsphere matrix. Moreover, upon dispersion into the polymer gel, the rate of drug release during initial diffusion phases slowed relative to microspheres alone. In conclusion, this study reports the development of PLGA microspheres with high payloads and their PLGA-PEG-PLGA gel based formulations. Drug release equations have been developed that effectively describe the triphasic GCV release.
Salama, Alaa H; Mahmoud, Azza A; Kamel, Rabab
Our objective was to prepare nanoparticulate system using a simple yet attractive innovated method as an ophthalmic delivery system for fluocinolone acetonide to improve its ocular bioavailability. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles were prepared by adopting thin film hydration method using PLGA/poloxamer 407 in weight ratios of 1:5 and 1:10. PLGA was used in 75/25 and 50/50 copolymer molar ratio of DL-lactide/glycolide. Results revealed that using PLGA with lower glycolic acid monomer ratio exhibited high particle size (PS), zeta potential (ZP) and drug encapsulation efficiency (EE) values with slow drug release pattern. Also, doubling the drug concentration during nanoparticles preparation ameliorated its EE to reach almost 100%. Furthermore, studies for separating the un-entrapped drug in nanoparticles using centrifugation method at 20,000 rpm for 30 min showed that the separated clear supernatant contained nanoparticles encapsulating an important drug amount. Therefore, separation of un-entrapped drug was carried out by filtrating the preparation using 20-25 μm pore size filter paper to avoid drug loss. Aiming to increase the PLGA nanoparticles mucoadhesion ability, surface modification of selected formulation was done using different amount of stearylamine and chitosan HCl. Nanoparticles coated with 0.1% w/v chitosan HCl attained most suitable results of PS, ZP and EE values as well as high drug release properties. Transmission electron microphotographs illustrated the deposition of chitosan molecules on the nanoparticles surfaces. Pharmacokinetic studies on Albino rabbit's eyes using HPLC indicated that the prepared novel chitosan-coated PLGA nanoparticles subjected to separation by filtration showed rapid and extended drug delivery to the eye.
Simonoska Crcarevska, M; Geskovski, N; Calis, S; Dimchevska, S; Kuzmanovska, S; Petruševski, G; Kajdžanoska, M; Ugarkovic, S; Goracinova, K
Modified nanoprecipitation method was used for improved incorporation of hydrophilic drug (irinotecan hydrochloride) into the PLGA/PEO-PPO-PEO blended and blended/adsorbed nanoparticles. One factor at a time (OFAT) variation experiments were conducted in order to determine key formulation factors (concentration and volume of drug solution, evaporation rate and PLGA/PEO-PPO-PEO ratio) influencing nanoparticle properties (particle size and size distribution, encapsulation efficiency, drug content, zeta potential, drug dissolution rate, as well as protein binding capacity). The insight into in vivo behavior of prepared nanoparticles and their potential for effective anticancer treatment was gained by performing biodistribution and cell culture studies as part of OFAT experiments. The mean particle size, mainly dependent upon PLGA/PEO-PPO-PEO ratio, was in the range of 112-125 nm, with narrow unimodal distribution (PDI∼0.1). Encapsulation efficiency (32-63%) was impacted by evaporation rate and PLGA/PEO-PPO-PEO ratio. Drug content (0.2-1.51%) and controlled release properties were related to the influence of all tested formulation factors. Structural information for the studied nanoparticles was obtained using DSC and FT-IR spectroscopy. Zeta potential values indicated that presence of PEO-PPO-PEO in the formulations shielded the high surface negative charge of PLGA. PEO-PPO-PEO surface coverage of PLGA/PEO-PPO-PEO blended as well as blended/adsorbed nanoparticles depended upon amount of used PEO-PPO-PEO during preparation procedure and was related to the protein resistant characteristics of nanoparticles. Results from in vivo studies evidenced prolonged blood circulation time of the prepared nanoparticles, while cell culture studies indicated higher in vitro bioefficacy compared to free drug. Performed experiments defined possible design space and justified further optimization of formulation using experimental design studies. Copyright © 2013 Elsevier B.V. All
Das, Nilanjana; Madan, Parshotam; Lin, Senshang
Insulin-loaded buccal Pluronic F-127 (PF-127) gel formulations were fabricated to study the effect of PF-127 concentration, insulin concentration, presence of salt, addition of polymer, and permeation enhancer on their gelation time, mucoadhesion force, release and permeation characteristics of insulin from the gels. Thereafter, the principle of statistical optimization to prepare a gel formulation having the potential for buccal delivery of basal insulin in diabetic patients was employed. The gelation time decreased as the concentration of PF-127 increased. Presence of salts as well as addition of polymer, such as methyl cellulose (MC) and hydroxypropylmethyl cellulose (HPMC) decreased the gelation time. An increase in PF-127 concentration and addition of MC and HPMC increased the mucoadhesion force of the gel formulations. Release and permeation of insulin from the gel formulations decreased with increased concentration of PF-127, presence of salts, and addition of MC and HPMC. Permeation of insulin from the optimized gel formulation was 93.17 (+/- 0.058, n = 3) microg/cm(2) which was not only found in close agreement with predicted results from the model equations used for the formulation optimization but also considered comparable to clinical setting. Therefore, the development of optimized buccal insulin-loaded Pluronic F-127 gels using a statistical experimental design is feasible.
Williams, Rebecca S; Kozan, Pinar; Samocha-Bonet, Dorit
Type 2 diabetes is increasingly being recognised as a global health crisis (World Health Organisation). Insulin resistance is closely associated with obesity and precedes the development of type 2 diabetes. However, there is now increasing evidence to suggest that diet itself may independently be associated with type 2 diabetes risk. A diet with a high acid load (or high potential renal net acid load, PRAL) can result in a decrease in pH towards the lower end of the normal physiological range, which may in turn lead to the development of insulin resistance. Conversely, reducing dietary acid load (the so called 'alkaline diet') may be protective and prevent the onset of type 2 diabetes. Here, we explore the influence of dietary acid load on the development of mild metabolic acidosis and induction of insulin resistance. Whilst large prospective cohort studies link high dietary acid load or low serum bicarbonate with the development of type 2 diabetes, the effect of a diet with a low acid (or high alkaline) load remains unclear. Further interventional studies are required to investigate the influence of dietary composition on the body's acid/base balance, insulin resistance and incidence of type 2 diabetes. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.
Coelho, Eduardo Antonio Ferraz; Tavares, Carlos Alberto Pereira; Lima, Karla de Melo; Silva, Célio Lopes; Rodrigues, José Maciel; Fernandes, Ana Paula
Heat shock proteins (HSPs) are highly conserved among different organisms. A mycobacterial HSP65 DNA vaccine was previously shown to have prophylactic and immunotherapeutic effects against Mycobacterium tuberculosis infection in mice. Here, BALB/c mice were immunized with mycobacterial DNA-hsp65 or with DNA-hsp65 and trehalose dymicolate (TDM), both carried by biodegradable microspheres (MHSP/TDM), and challenged with Leishmania (Leishmania) major. MHSP/TDM conferred protection against L. major infection, as indicated by a significant reduction of edema and parasite loads in infected tissues. Although high levels of interferon-gamma and low levels of interleukin (IL)-4 and IL-10 were detected in mice immunized with DNA-hsp65 or MHSP/TDM, only animals immunized with MHSP/TDM displayed a consistent Th1 immune response, i.e., significantly higher levels of anti-soluble Leishmania antigen (SLA) immunoglobulin G (IgG)2a and low anti-SLA IgG1 antibodies. These findings indicate that encapsulated MHSP/TDM is more immunogenic than naked hsp65 DNA, and has great potential to improve vaccine effectiveness against leishmaniasis and tuberculosis.
Tansık, Gülistan; Yakar, Arzu; Gündüz, Ufuk
One of the main problems of current cancer chemotherapy is the lack of selectivity of anti-cancer drugs to tumor cells, which leads to systemic toxicity and adverse side effects. In order to overcome these limitations, researches on controlled drug delivery systems have gained much attention. Nanoscale-based drug delivery systems provide tumor targeting. Among many types of nanocarriers, superparamagnetic nanoparticles with their biocompatible polymer coatings can be targeted to an intented site by an external magnetic field. Thus, the drug can be carried to the targeted site safely. The aim of this study is to prepare poly( dl-lactic- co-glycolic acid) (PLGA)-coated magnetic nanoparticles and load anti-cancer drug, doxorubicin to them. For this purpose, magnetite (Fe3O4) iron oxide nanoparticles were synthesized as a magnetic core material (MNP) and then coated with oleic acid. Oleic acid-coated MNP (OA-MNP) was encapsulated into PLGA. Effects of different OA-MNP/PLGA ratios on magnetite entrapment efficiency were investigated. Doxorubicin-loaded magnetic polymeric nanoparticles (DOX-PLGA-MNP) were prepared. After the characterization of prepared nanoparticles, their cytotoxic effects on MCF-7 cell line were studied. PLGA-coated magnetic nanoparticles (PLGA-MNP) had a proper size and superparamagnetic character. The highest magnetite entrapment efficiency of PLGA-MNP was estimated as 63 % at 1:8 ratio. Cytotoxicity studies of PLGA-MNP did not indicate any notable cell death between the concentration ranges of 2 and 125 μg/ml. Drug loading efficiency was estimated as 32 %, and it was observed that DOX-PLGA-MNP showed significant cytotoxicity on MCF-7 cells compared to PLGA-MNP. The results showed that prepared nanoparticles have desired size and superparamagnetic characteristics without serious toxic effects on cells. These nanoparticles may be suitable for targeted drug delivery applications.
Nimptsch, Katharina; Brand-Miller, Jennie C; Franz, Mary; Sampson, Laura; Willett, Walter C; Giovannucci, Edward
Dietary glycemic index and load are widely used to estimate the effect of carbohydrate-containing foods on postprandial blood glucose concentrations and as surrogates for insulin response. The food insulin index (II) directly quantifies the postprandial insulin secretion of a food and takes into account foods with a low or no carbohydrate content. We investigated the average dietary II and insulin load (IL) in relation to biomarkers of glycemic control, plasma lipids, and inflammation markers. In a cross-sectional setting and with the use of data from the Nurses' Health Study and the Health Professionals Follow-Up Study, we measured plasma concentrations of C-peptide, glycated hemoglobin (Hb A(1c)), HDL cholesterol, LDL cholesterol, triglycerides, C-reactive protein (CRP), and interleukin-6 (IL-6) in fasting blood samples of 4002 healthy men and women. The dietary II and IL were assessed from food-frequency questionnaires by using directly analyzed or published food II data. After multivariate adjustment, participants in the highest quintile of II had 26% higher triglyceride concentrations than did participants in the lowest quintile of II (P for trend < 0.0001). This association was strongest in obese [body mass index (in kg/m(2)) ≥30] participants (difference between highest and lowest quintiles in the II: 72%; P for trend = 0.01). Dietary II was inversely associated with HDL cholesterol in obese participants (difference: -18%; P for trend = 0.03). Similar associations were seen for the IL. Dietary II and IL were not significantly associated with plasma C-peptide, Hb A(1c), LDL cholesterol, CRP, or IL-6. Dietary II and IL were not associated with fasting biomarkers of glycemic control but may be physiologically relevant to plasma lipids, especially in obese individuals.
Lau, Cathrine; Faerch, Kristine; Glümer, Charlotte; Tetens, Inge; Pedersen, Oluf; Carstensen, Bendix; Jørgensen, Torben; Borch-Johnsen, Knut
To examine the relationship between daily glycemic index, daily glycemic load, simple sugars, dietary fiber, and the prevalence of a measure of insulin resistance in 30- to 60-year-old nondiabetic Danish men and women. The Inter99 study is a nonpharmacological intervention study. We used baseline data and examined cross-sectional associations between carbohydrate-related dietary factors and an estimate of insulin resistance in 5,675 subjects at 30-60 years. The dietary intake was estimated from a self-administered food frequency questionnaire, and insulin resistance was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). Multiple regressions were performed with HOMA-IR as the dependent variable and carbohydrate-related factors as explanatory variables. All models were adjusted for age, sex, smoking, physical activity, total energy intake, BMI, and waist circumference. Intake of lactose was positively associated with HOMA-IR (P < 0.0001), whereas daily glycemic load and intake of glucose, fructose, dietary fiber, total carbohydrate, fruit, and vegetables were inversely associated with HOMA-IR (P < 0.05). Intake of dietary fiber explained the associations with daily glycemic load and total carbohydrate and attenuated the association with fruit and vegetables. No significant associations were observed for daily glycemic index or sucrose. Habitual intake of diets with a high glycemic index and high glycemic load or diets with a high content of total carbohydrate including simple sugars was not associated with the probability of having insulin resistance. Furthermore, intake of dietary fiber was inversely associated with the probability of having insulin resistance.
Chen, Hongli; Xie, Li Qin; Qin, Jingwen; Jia, Yajing; Cai, Xinhua; Nan, WenBin; Yang, Wancai; Lv, Feng; Zhang, Qi Qing
In this study, poly(d,l-lactide-co-glycolide) nanoparticles (PLGA NPs) with biotinylated chitosan (Bio-CS)-surface modification were prepared to be usded as a tumor-targeted and prolonged delivery system for anticancer drugs. Epirubicin (EPB), as a model drug, was encapsulated into Bio-CS surface modified PLGA (Bio-CS-PLGA) NPs with a drug encapsulation efficiency of 84.1 ± 3.4%. EPB-loaded Bio-CS-PLGA NPs were spherical shaped, and had a larger size and higher positive zeta potential compared to the unmodfied EPB-loaded PLGA NPs. The in vitro drug releases showed that EPB-loaded Bio-CS-PLGA NPs exhibited relatively constant drug release kinetics during the first 48 h and the drug burst release significantly decreased in comparison to the unmodified PLGA NPs. The results of MTS assays showed that Bio-CS-PLGA NPs markedly increased the cytotoxicity of EPB, compared to both the unmodified PLGA NPs and the CS-PLGA NPs. The uptakes of NPs in human breast cancer MCF-7 cells were evaluated by the flow cytometry and the confocal microscope. The results revealed that Bio-CS-PLGA NPs exhibited a greater extent of cellular uptake than the unmodified PLGA NPs and CS-PLGA NPs. Moreover, the cellular uptake of Bio-CS-PLGA NPs was evidently inhibited by the endocytic inhibitors and the receptor ligand, indicating that biotin receptor-mediated endocytosis was perhaps involved in the cell entry of Bio-CS-PLGA NPs. In MCF-7 tumor-bearing nude mice, EPB-loaded Bio-CS-PLGA NPs were efficiently accumulated in the tumors. In summary, Bio-CS-PLGA NPs displayed great potential for application as the carriers of anticancer drugs.
Preparation, characterization and in vivo evaluation of a combination delivery system based on hyaluronic acid/jeffamine hydrogel loaded with PHBV/PLGA blend nanoparticles for prolonged delivery of Teriparatide.
Bahari Javan, Nika; Montazeri, Hamed; Rezaie Shirmard, Leila; Jafary Omid, Nersi; Barbari, Ghullam Reza; Amini, Mohsen; Ghahremani, Mohammad Hossein; Rafiee-Tehrani, Morteza; Abedin Dorkoosh, Farid
In the current study, biodegradable PHBV/PLGA blend nanoparticles (NPs) containing Teriparatide were loaded in hyaluronic acid/jeffamine (HA-JEF ED-600) hydrogel to prepare a combination delivery system (CDS) for prolonged delivery of Teriparatide. The principal purpose of the present study was to formulate an effective and prolonged Teriparatide delivery system in order to reduce the frequency of injection and thus enhance patient's compliance. Morphological properties, swelling behaviour, crosslinking efficiency and rheological characterization of HA-JEF ED-600 hydrogel were evaluated. The CDS was acquired by adding PHBV/PLGA NPs to HA-JEF ED-600 hydrogel simultaneously with crosslinking reaction. The percentage of NPs incorporation within the hydrogel as well as the loading capacity and morphology of Teriparatide loaded CDS were examined. Intrinsic fluorescence and circular dichroism spectroscopy proved that Teriparatide remains stable after processing. The release profile represented 63% Teriparatide release from CDS within 50days with lower burst release compared to NPs and hydrogel. MTT assay was conducted by using NIH3T3 cell line and no sign of reduction in cell viability was observed. Based on Miller and Tainter method, LD50 of Teriparatide loaded CDS was 131.8mg/kg. In vivo studies demonstrated that Teriparatide loaded CDS could effectively increase serum calcium level after subcutaneous injection in mice. Favourable results in the current study introduced CDS as a promising candidate for controlled delivery of Teriparatide and pave the way for future investigations in the field of designing prolonged delivery systems for other peptides and proteins.
Cui, Fuying; Qian, Feng; Zhao, Ziming; Yin, Lichen; Tang, Cui; Yin, Chunhua
To improve the efficiency of insulin via oral administration, pH-sensitive carboxylated chitosan grafted poly(methyl methacrylate) nanoparticles (CCGN) were prepared. CCGN were characterized by (1)H NMR, dynamic light scattering, zeta potential, and transmission electron microscopy, and the hypoglycemic effect of insulin loaded CCGN via the oral route was evaluated in normal and diabetic rats. CCGN exhibited a homogeneous morphology and a spherical shape with core-shell structure. They were aggregated in simulated gastric fluid while separated in simulated intestinal fluid. Insulin was mainly located in the shell of the CCGN via hydrogen bonding, electrostatic interaction, and Van der Waals force. Insulin release from the CCGN exhibited a pH-sensitive property in that it had a slow release rate at pH 2.0 and a fast release rate at pH 6.8 and 7.4. The pharmacological bioavailability after oral administration of insulin loaded CCGN at a dose of 25 IU/kg was found to be 9.7%. Besides, CCGN showed desirable tissue and blood compatibility. Therefore, the CCGN would be a promising delivery carrier for protein drugs via the oral route.
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Bi, Ru; Shao, Wei; Wang, Qun; Zhang, Na
Nowadays, growing attention has been paid to the pulmonary region as a target for the delivery of peptide and protein drugs, especially macromolecules with systemic effect like insulin, since the pulmonary route exhibits numerous benefits to be an alternative for repeated injection. Furthermore, encapsulation of insulin into liposomal carriers is an attractive way to increase drug retention time and control the drug release in the lung; however, its long-term stability during storage in the reservoir and the process of aerosolization might be suspected when practically applied. Thus, the aim of this study was to design and characterize dry powder inhalation of insulin-loaded liposomes prepared by novel spray-freeze-drying method for enhanced pulmonary delivery. Process variables such as compressed air pressure, pump speed, and concentration were optimized for parameters such as mean particle diameter, moisture content, and fine particle fraction of the produced powders. Influence of different kinds and amounts of lyoprotectants was also evaluated for the best preservation of the drug entrapped in the liposome bilayers after the dehydration-rehydration cycle. The in vivo study of intratracheal instillation of insulin-loaded liposomes to diabetic rats showed successful hypoglycemic effect with low blood glucose level and long-lasting period and a relative pharmacological bioavailability as high as 38.38% in the group of 8 IU/kg dosage.
Koska, J; Blazícek, P; Marko, M; Grna, J D; Kvetnanský, R; Vigas, M
Exercise, insulin-induced hypoglycemia and oral glucose loads (50 g and 100 g) were used to compare the production of malondialdehyde and the activity of antioxidant enzymes in healthy subjects. Twenty male volunteers participated in the study. Exercise consisted of three consecutive work loads on a bicycle ergometer of graded intensity (1.5, 2.0, and 2.5 W/kg, 6 min each). Hypoglycemia was induced by insulin (Actrapid MC Novo, 0.1 IU/kg, i.v.). Oral administration of 50 g and 100 g of glucose was given to elevate plasma glucose. The activity of superoxide dismutase (SOD) was determined in red blood cells, whereas glutathione peroxidase (GSH-Px) activity was measured in whole blood. The concentration of malondialdehyde (MDA) was determined by HPLC, catecholamines were assessed radioenzymatically and glucose was measured by the glucose-oxidase method. Exercise increased MDA concentrations, GSH-Px and SOD activities as well as plasma noradrenaline and adrenaline levels. Insulin hypoglycemia increased plasma adrenaline levels, but the concentrations of MDA and the activities of GSH-Px and SOD were decreased. Hyperglycemia increased plasma MDA concentrations, but the activities of GSH-Px and SOD were significantly higher after a larger dose of glucose only. Plasma catecholamines were unchanged. These results indicate that the transient increase of plasma catecholamine and insulin concentrations did not induce oxidative damage, while glucose already in the low dose was an important triggering factor for oxidative stress.
Ikizler, Halil O; Zelnick, Leila; Ruzinski, John; Curtin, Laura; Utzschneider, Kristina M; Kestenbaum, Bryan; Himmelfarb, Jonathan; de Boer, Ian H
In chronic kidney disease (CKD), dietary acid may promote metabolic acidosis and insulin resistance, which in turn may contribute to adverse clinical health outcomes. We examined associations between dietary acid load, serum bicarbonate, and insulin sensitivity in CKD. In a cross-sectional study, we collected 3-day prospective food diaries to quantify dietary acid load as net endogenous acid production (NEAP, the nonvolatile acid load produced by the diet's acid balance) and potential renal acid load (PRAL). We measured urine net acid excretion (NAE) in 24-hour urine samples. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp. Forty-two patients with CKD Stages 3 to 5 attending nephrology clinics in the Pacific Northwest and 21 control subjects (estimated glomerular filtration rate [eGFR] ≥ 60 mL/minute/1.73 m(2)). Serum bicarbonate and insulin sensitivity (SIclamp). Mean age was 60.8 ± 13.6 years, and 54% of participants were men. Mean eGFR and serum bicarbonate concentrations were 34.4 ± 13.1 mL/minute/1.73 m(2) and 24.1 ± 2.9 mEq/L for participants with CKD and 88.6 ± 14.5 mL/minute/1.73 m(2) and 26.3 ± 1.8 mEq/L for control subjects, respectively. Mean NEAP, PRAL, and NAE were 58.2 ± 24.3, 9.7 ± 18.4, and 32.1 ± 19.8 mEq/day, respectively. Considering all participants, dietary acid load was significantly, inversely associated with serum bicarbonate, adjusting for age, gender, race, eGFR, body mass index, and diuretic use: -1.2 mEq/L per standard deviation (SD) NEAP (95% confidence interval [CI] -1.8 to -0.6, P < .0001); -0.9 mEq/L bicarbonate per SD PRAL (95% CI -1.5 to -0.4, P = .0005); -0.7 mEq/L bicarbonate per SD NAE (95% CI -1.2 to -0.1, P = .01). These associations were similar in participants with and without CKD. However, neither NEAP and PRAL nor NAE was significantly associated with SIclamp. Serum bicarbonate was also not significantly associated with SIclamp. In CKD, dietary acid load is associated with serum bicarbonate
Xu, Bin; Jiang, Guohua; Yu, Weijiang; Liu, Depeng; Liu, Yongkun; Kong, Xiangdong; Yao, Juming
To improve insulin bioavailability and overcome multiple barriers for oral delivery of insulin, the composite nanocarriers (PLGA/FA-CS) prepared from poly(lactide-co-glycoside) (PLGA) and folic acid modified chitosan (FA-CS) were fabricated via electrostatic self-assembly method. The resultant composite nanocarriers exhibited low cytotoxicity against HT-29 cells and excellent stability against protein solution. The chemical stability of loaded insulin against digestive enzyme were established in presence of simulated gastric fluid (SGF) containing pepsin and simulated intestinal fluid (SIF) containing pancreatin, respectively. The uptake behavior of HT-29 cells was evaluated by confocal laser scanning microscope. After oral administration to the diabetic rats, an effective hypoglycemic effect was obtained compared with subcutaneous injection of insulin. This work suggests that the as-prepared composite nanocarriers may be a promising drug delivery system for oral administration of insulin and other biomacromolecules. Copyright © 2017 Elsevier B.V. All rights reserved.
Zhu, Siqi; Chen, Shuangxi; Gao, Yuan; Guo, Feng; Li, Fengying; Xie, Baogang; Zhou, Jianliang; Zhong, Haijun
Biodegradable polymer nanoparticle drug carriers are an attractive strategy for oral delivery of peptide and protein drugs. However, their ability to cross the intestinal epithelium membrane is largely limited. Therefore, in the present study, cell-penetrating peptides (R8, Tat, penetratin) and a secretion peptide (Sec) with N-terminal stearylation were introduced to modify nanoparticles (NPs) on the surface to improve oral bioavailability of peptide and protein drugs. In vitro studies conducted in Caco-2 cells showed the value of the apparent permeability coefficient (Papp) of the nanoparticles co-modified with Sec and penetratin (Sec-Pen-NPs) was about two-times greater than that of the nanoparticles modified with only penetratin (Pen-NPs), while the increase of transcellular transport of nanoparticles modified together with Sec and R8 (Sec-R8-NPs), or Sec and Tat (Sec-Tat-NPs), was not significant compared with nanoparticles modified with only R8 (R8-NPs) or Tat (Tat-NPs). Using insulin as the model drug, in vivo studies performed on rats indicated that compared to Pen-NPs, the relative bioavailability of insulin for Sec-Pen-NPs was 1.71-times increased after ileal segments administration, and stronger hypoglycemic effects was also observed. Therefore, the nanoparticles co-modified with penetratin and Sec could act as attractive carriers for oral delivery of insulin.
Momoh, Mumuni A; Kenechukwu, Franklin C; Nnamani, Petra O; Umetiti, Jennifer C
Effective oral insulin delivery has remained a challenge to the pharmaceutical industry. This study was designed to evaluate the effect of magnesium stearate on the properties of insulin-loaded Eudragit® RL 100 entrapped mucoadhesive microspheres. Microspheres containing Eudragit® RL 100, insulin, and varying concentrations of magnesium stearate (agglomeration-preventing agent) were prepared by emulsification-coacervation method and characterized with respect to differential scanning calorimetry (DSC), morphology, particle size, loading efficiency, mucoadhesive and micromeritics properties. The in vitro release of insulin from the microspheres was performed in simulated intestinal fluid (SIF, pH 7.2) while the in vivo hypoglycemic effect was investigated by monitoring the plasma glucose level of the alloxan-induced diabetic rats after oral administration. Stable, spherical, brownish, mucoadhesive, discrete and free flowing insulin-loaded microspheres were formed. While the average particle size and mucoadhesiveness of the microspheres increased with an increase in the proportion of magnesium stearate, loading efficiency generally decreased. After 12 h, microspheres prepared with Eudragit® RL 100: magnesium stearate ratios of 15:1, 15:2, 15:3 and 15:4 released 68.20 ± 1.57, 79.40 ± 1.52, 76.60 ± 1.93 and 70.00 ± 1.00 (%) of insulin, respectively. Reduction in the blood glucose level for the subcutaneously (sc) administered insulin was significantly (p ≤ 0.05) higher than for most of the formulations. However, the blood glucose reduction effect produced by the orally administered insulin-loaded microspheres prepared with four parts of magnesium stearate and fifteen parts of Eudragit® RL 100 after 12 h was equal to that produced by subcutaneously administered insulin solution. The results of this study can suggest that this carrier system could be an alternative for the delivery of insulin.
Nan, Kaihui; Ma, Feiyan; Hou, Huiyuan; Freeman, William R; Sailor, Michael J; Cheng, Lingyun
A water-soluble anthracycline antibiotic drug (daunorubicin, DNR) was loaded into oxidized porous silicon (pSiO2) microparticles and then encapsulated with a layer of polymer (poly lactide-co-glycolide, PLGA) to investigate their synergistic effects in control of DNR release. Similarly fabricated PLGA-DNR microspheres without pSiO2, and pSiO2 microparticles without PLGA were used as control particles. The composite microparticles synthesized by a solid-in-oil-in-water emulsion method have mean diameters of 52.33±16.37μm for PLGA-pSiO2_21/40-DNR and the mean diameter of 49.31±8.87μm for PLGA-pSiO2_6/20-DNR. The mean size, 26.00±8μm, of PLGA-DNR was significantly smaller, compared with the other two (P<0.0001). Optical microscopy revealed that PLGA-pSiO2-DNR microspheres contained multiple pSiO2 particles. In vitro release experiments determined that control PLGA-DNR microspheres completely released DNR within 38days and control pSiO2-DNR microparticles (with no PLGA coating) released DNR within 14days, while the PLGA-pSiO2-DNR microspheres released DNR for 74days. Temporal release profiles of DNR from PLGA-pSiO2 composite particles indicated that both PLGA and pSiO2 contribute to the sustained release of the payload. The PLGA-pSiO2 composite displayed a more constant rate of DNR release than the pSiO2 control formulation, and displayed a significantly slower release of DNR than either the PLGA or pSiO2 formulations. We conclude that this system may be useful in managing unwanted ocular proliferation when formulated with antiproliferation compounds such as DNR.
Mishraki-Berkowitz, T; Ben Ishai, P; Aserin, A; Feldman, Yu; Garti, N
The dielectric behavior of the insulin-loaded HII mesophase (containing GMO-TAG-water-glycerol-insulin) was studied using two empty reference systems (GMO-TAG-water and GMO-TAG-water-glycerol) at a frequency range of 10(-2)-10(6) Hz, and a temperature range of 290-333 K. Three clearly defined relaxation processes were observed and assigned to the reorientation of GMO polar heads, the tangential movement of counterions at the interface, and the movements of TAGs through the lipid tail. Upon addition of glycerol, a heterogeneous inner structure was formed within the HII cylinders: the water-glycerol core surrounded by a water rigid layer. Upon heating, two critical points were detected referring to the dehydration of the GMO heads (at 304 K, similar to the water-filled HII system) and to energetic modifications (at 316 K), resulting in breaking of the water layer allowing on-demand controlled release. Insulin incorporation combined the features of both reference HII systems. Yet, unlike the empty HII systems, insulin perturbed the GMO-water interface while decreasing the movement of the GMO headgroup, and reducing T0 (296 K). No interactions were formed between the dipole of each counterion at the interface region and the matrix (the GMO), fitting the Debye process. Dynamic behavior was observed, pointing to mobility between the hexagonal rods themselves, enabling controlled release from the HII carrier.
Wang, Yunfei; Liu, Peifeng; Qiu, Lihua; Sun, Ying; Zhu, Mingjie; Gu, Liying; Di, Wen; Duan, Yourong
Construction on the nanoparticles with lower toxicity and specific tumor targeting properties is challenging and requires careful design of composition, size, physicochemical properties tailored for the nanoparticles. Here the epidermal growth factor (EGF) modified methoxy polyethylene glycol-polylactic-co-glycolic acid-polylysine (mPEG-PLGA-PLL) encapsulated cisplatin (CDDP) nanoparticles (CDDP-NPs-EGF) was prepared to for solving the toxicity of CDDP and improving therapeutic efficiency. The remarkable features of CDDP-NPs-EGF are increasing cytotoxicity that attribute to effective cell cycle arrest and high cell apoptosis in vitro. In vivo, the CDDP-NPs-EGF change drug distribution, decrease the nephrotoxicity of CDDP and improve significantly therapeutic efficiency without inducing obvious system toxicity, verifying its key role of the CDDP-NPs-EGF in lowering drug toxicity and enhancing the antitumor efficiency for SKOV3 cancer in mice. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.
Ikizler, H. Omer; Zelnick, Leila; Ruzinski, John; Curtin, Laura; Utzschneider, Kristina M.; Kestenbaum, Bryan; Himmelfarb, Jonathan; de Boer, Ian H.
Objective In chronic kidney disease (CKD), dietary acid may promote metabolic acidosis and insulin resistance, which in turn may contribute to adverse clinical health outcomes. We examined associations between dietary acid load, serum bicarbonate, and insulin sensitivity in CKD. Design In a cross-sectional study, we collected 3-day prospective food diaries to quantify dietary acid load as net endogenous acid production (NEAP, the nonvolatile acid load produced by the diet’s acid balance) and potential renal acid load (PRAL). We measured urine net acid excretion (NAE) in 24-hour urine samples. Insulin sensitivity was measured by hyperinsulinemic euglycemic clamp. Subjects 42 patients with CKD stages 3–5 attending nephrology clinics in the Pacific Northwest and 21 control subjects (eGFR ≥60mL/min/1.73m2). Main outcome measures Serum bicarbonate and insulin sensitivity (SIclamp). Results Mean age was 60.8±13.6 years and 54% of participants were men. Mean eGFR and serum bicarbonate concentrations were 34.4±13.1 mL/min/1.73m2 and 24.1±2.9 mEq/L for participants with CKD and 88.6±14.5 mL/min/1.73m2 and 26.3±1.8 mEq/L for control subjects, respectively. Mean NEAP, PRAL, and NAE were 58.2±24.3, 9.7±18.4, and 32.1±19.8 mEq/day, respectively. Considering all participants, dietary acid load was significantly, inversely associated with serum bicarbonate, adjusting for age, sex, race, eGFR, BMI, and diuretic use: −1.2 mEq/L per SD NEAP (95% CI −1.8, −0.6, p<0.0001); −0.9 mEq/L bicarbonate per SD PRAL (95% CI −1.5, −0.4, p=0.0005); −0.7 mEq/L bicarbonate per SD NAE (95% CI −1.2, −0.1, p=0.01). These associations were similar in participants with and without CKD. However, neither NEAP, PRAL, nor NAE was significantly associated with SIclamp. Serum bicarbonate was also not significantly associated with SIclamp. Conclusions In CKD, dietary acid load is associated with serum bicarbonate, suggesting that acidosis may be improved by dietary changes, but
Wen, Zhen; Li, Gang; Lin, Dong-Hai; Wang, Jun-Teng; Qin, Li-Fang; Guo, Gui-Ping
The present study is to establish Caco-2/HT29-MTX co-cultured cells and investigate the transport capability of PLGA nanoparticles with different surface chemical properties across Caco-2/HT29-MTX co-cultured cells. PLGA-NPs, mPEG-PLGA-NPs and chitosan coated PLGA-NPs were prepared by nanoprecipitation method using poly(lactic-co-glycolic acid) as carrier material with surface modified by methoxy poly(ethylene glycol) and chitosan. The particle size and zeta potential of nanoparticles were measured by dynamic light scattering. Coumarin 6 was used as a fluorescent marker in the transport of nanoparticles investigated by confocal laser scanning microscopy. The transport of furanodiene (FDE) loaded nanoparticles was quantitively determined by high performance liquid chromatography. Colchicine and nocodazole were used in the transport study to explore the involved endocytosis mechanisms of nanoparticles. Distribution of the tight junction proteins ZO-1 was also analyzed by immunofluorescence staining. The results showed that the nanoparticles dispersed uniformly. The zeta potential of PLGA-NPs was negative, the mPEG-PLGA-NPs was close to neutral and the CS-PLGA-NPs was positive. The entrapment efficiency of FDE in all nanoparticles was higher than 75%. The transport capability of mPEG-PLGA-NPs across Caco-2/HT29-MTX co-cultured cells was higher than that of PLGA-NPs and CS-PLGA-NPs. Colchicine and nocodazole could significantly decrease the transport amount of nanoparticles. mPEG-PLGA-NPs could obviously reduce the distribution of ZO-1 protein than PLGA-NPs and CS-PLGA-NPs. The transport mechanism of PLGA-NPs and mPEG-PLGA-NPs were indicated to be a combination of endocytosis and paracellular way, while CS-PLGA-NPs mainly relied on the endocytosis way. PEG coating could shield the surface charge and enhance the hydrophilicity of PLGA nanoparticles, which leads mPEG-PLGA-NPs to possess higher anti-adhesion activity. As a result, mPEG-PLGA-NPs could penetrate the mucus
Mo, Yunfei; Guo, Rui; Liu, Jianghui; Lan, Yong; Zhang, Yi; Xue, Wei; Zhang, Yuanming
Although extensively used in the fields of drug-carrier and tissue engineering, the biocompatibility and mechanical properties of polylactide-polyglycolide (PLGA) nanofiber membranes still limit their applications. The objective of this study was to improve their utility by introducing cellulose nanocrystals (CNCs) into PLGA nanofiber membranes. PLGA and PLGA/CNC composite nanofiber membranes were prepared via electrospinning, and the morphology and thermodynamic and mechanical properties of these nanofiber membranes were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The cytocompatibility and cellular responses of the nanofiber membranes were also studied by WST-1 assay, SEM, and confocal laser scanning microscopy (CLSM). Incorporation of CNCs (1, 3, 5, and 7 wt.%) increased the average fiber diameter of the prepared nanofiber membranes from 100 nm (neat PLGA) to ∼400 nm (PLGA/7 wt.% CNC) and improved the thermal stability of the nanofiber membranes. Among the PLGA/CNC composite nanofiber membranes, those loaded with 7 wt.% CNC nanofiber membranes had the best mechanical properties, which were similar to those of human skin. Cell culture results showed that the PLGA/CNC composite nanofiber membranes had better cytocompatibility and facilitated fibroblast adhesion, spreading, and proliferation compared with neat PLGA nanofiber membranes. These preliminary results suggest that PLGA/CNC composite nanofiber membranes are promising new materials for the field of skin tissue engineering.
Tang, Xiaolong; Liang, Yong; Feng, Xiaojun; Zhang, Rongbo; Jin, Xu; Sun, Leilei
Multidrug resistance (MDR) is a major hurdle to the success of cancer chemotherapy. Poloxamers have been shown to reverse MDR by inhibiting the P-glycoprotein (P-gp) pump. The objective of this research is to test the feasibility of docetaxel-loaded PLGA-TPGS/Poloxamer 235 nanoparticles to overcome MDR in docetaxel-resistant human breast cancer cell line. Docetaxel-loaded nanoparticles were prepared by a modified nanoprecipitation method using PLGA-TPGS and PLGA-TPGS/Poloxamer 235 mixture, respectively. The PLGA-TPGS/Poloxamer 235 nanoparticles were of spherical shape and have a rough and porous surface. The docetaxel-loaded PLGA-TPGS/Poloxamer 235 porous nanoparticles which had an average size of around 180nm with a narrow size distribution were stable, showing almost no change in particle size and surface charge during the 3-month storage period. The in vitro drug release profile of both nanoparticle formulations showed a biphasic release pattern. There was an increased level of uptake of PLGA-TPGS/Poloxamer 235 porous nanoparticles (PPNPs) in docetaxel-resistant human breast cancer cell line, MCF-7/TXT, in comparison with PLGA-TPGS nanoparticles (PTNPs). The PLGA-TPGS/Poloxamer 235 porous nanoparticles produced significantly higher level of toxicity than both of PLGA-TPGS nanoparticle formulation and Taxotere® both in vitro and in vivo, indicating docetaxel-loaded PLGA-TPGS/Poloxamer 235 porous nanoparticles have significant potential for the treatment of breast cancer.
Zhao, Wen; Li, Jiaojiao; Jin, Kaixiang; Liu, Wenlong; Qiu, Xuefeng; Li, Chenrui
Electrospun PLGA-based scaffolds have been applied extensively in biomedical engineering, such as tissue engineering and drug delivery system. Due to lack of the recognition sites on cells, hydropholicity and single-function, the applications of PLGA fibrous scaffolds are limited. In order to tackle these issues, many works have been done to obtain functional PLGA-based scaffolds, including surface modifications, the fabrication of PLGA-based composite scaffolds and drug-loaded scaffolds. The functional PLGA-based scaffolds have significantly improved cell adhesion, attachment and proliferation. Moreover, the current study has summarized the applications of functional PLGA-based scaffolds in wound dressing, vascular and bone tissue engineering area as well as drug delivery system.
Abulateefeh, Samer R; Alkilany, Alaaldin M
The preparation of microcapsules consisting of poly(D,L-lactide-co-glycolide) (PLGA) polymer shell and aqueous core is a clear challenge and hence has been rarely addressed in literature. Herein, aqueous core-PLGA shell microcapsules have been prepared by internal phase separation from acetone-water in oil emulsion. The resulting microcapsules exhibited mean particle size of 1.1 ± 0.39 μm (PDI = 0.35) with spherical surface morphology and internal poly-nuclear core morphology as indicated by scanning electron microscopy (SEM). The incorporation of water molecules into PLGA microcapsules was confirmed by differential scanning calorimetry (DSC). Aqueous core-PLGA shell microcapsules and the corresponding conventional PLGA microspheres were prepared and loaded with risedronate sodium as a model drug. Interestingly, aqueous core-PLGA shell microcapsules illustrated 2.5-fold increase in drug encapsulation in comparison to the classical PLGA microspheres (i.e., 31.6 vs. 12.7%), while exhibiting sustained release behavior following diffusion-controlled Higuchi model. The reported method could be extrapolated to encapsulate other water soluble drugs and hydrophilic macromolecules into PLGA microcapsules, which should overcome various drawbacks correlated with conventional PLGA microspheres in terms of drug loading and release.
Formulation and in vitro characterization of inhalable polyvinyl alcohol-free rifampicin-loaded PLGA microspheres prepared with sucrose palmitate as stabilizer: efficiency for ex vivo alveolar macrophage targeting.
Diab, R; Brillault, J; Bardy, A; Gontijo, A V L; Olivier, J C
In this work a new formulation of inhalable rifampicin-loaded PLGA microspheres (RIF-MS) is proposed for the management of tuberculosis treatment. For their formulation, the non-biodegradable polyvinyl alcohol surfactant was replaced with a biodegradable and biocompatible sucrose ester, sucrose palmitate. The effects of critical process and formulation parameters have been investigated and the obtained microspheres were characterized in terms of size, morphology, encapsulation efficiencies and RIF release profile. The optimized RIF-MS showed high drug loading (34.2%, w/w), an aerodynamic diameter compliant with deep lung delivery and an in vitro gradual and almost complete drug release over a week. The drug release data fitted well to the Higuchi models suggesting a drug release governed by Fickian diffusion. The RIF-MS uptake qualitative and quantitative studies on ex vivo rat alveolar macrophages (AM) revealed an efficient internalization of RIF-MS and their location in the perinuclear area. RIF intracellular levels were 7-fold higher in AM incubated with RIF-MS than with an equivalent amount of free RIF. Copyright © 2012 Elsevier B.V. All rights reserved.
Zhao, Xiuhua; Shan, Chang; Zu, Yuangang; Zhang, Ying; Wang, Weiguo; Wang, Kunlun; Sui, Xiaoyu; Li, Ruiqiang
Insulin is the most effective and durable drug in the treatment of advanced stage diabetes. However, oral delivering insulin was a tough task for rapid enzymatic degradation. In this work, we designed and developed a delivery system composed of enteric nanosphere for oral delivery of insulin. The silica was selected for loading insulin, which surface has a lot of pores with a powerful adsorption capacity, advantages for permeability and slow-release. The insulin-loaded silica (Ins-SiO2) was prepared by adsorption in HCl solution. The Ins-SiO2 obtained was coated with the hydroxypropyl methylcellulose phthalate (HP55) by desolvation method, which is a good enteric coating material. The Ins-SiO2-HP55, an enteric nanosphere of insulin obtained were characterized by transmission electron microscope (TEM), surface area, Fourier-transform infrared (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results showed that insulin was loaded most in the pores of silica, while the HP55 coated on the extent of Ins-SiO2. In vitro drug release results revealed that the release of insulin from Ins-SiO2-HP55 was markedly reduced in simulated gastric fluid (SGF). By contrast, the release amount of insulin from Ins-SiO2-HP55 was increased significantly in simulated intestinal fluid (SIF). In vivo evaluation on diabetic animals showed the blood glucose level of diabetic rats could be effectively reduced after oral administration Ins-SiO2-HP55. There is marked hypoglycemic effect after 1h of taking the Ins-SiO2-HP55. After 3h, the GLU of rats of the Ins-SiO2-HP55 stably kept from 4.85 to 2.67 mmol/L that was significantly less than the normal level (6.7 mmol/L). However, that of rats taking raw insulin kept from 8.03 to 6.56 mmol/L that is higher than the normal level. These results suggested that Ins-SiO2-HP55 could have potential value in oral administration systems of diabetes chemotherapy.
Ibarra, Jaime; Melendres, Julio; Almada, Mario; Burboa, María G.; Taboada, Pablo; Juárez, Josué; Valdez, Miguel A.
In this work, we report the synthesis and characterization of a new hybrid nanoparticles system performed by magnetite nanoparticles, loaded in a PLGA matrix, and stabilized by different concentrations of chitosan. Magnetite nanoparticles were hydrophobized with oleic acid and entrapped in a PLGA matrix by the emulsion solvent evaporation method, after that, magnetite/PLGA/chitosan nanoparticles were obtained by adding dropwise magnetite/PLGA nanoparticles in chitosan solutions. Magnetite/PLGA nanoparticles produced with different molar ratios did not show significant differences in size and the 3:1 molar ratio showed best spherical shapes as well as uniform particle size. Isothermal titration calorimetry studies demonstrated that the first stage of PLGA-chitosan interaction is mostly regulated by electrostatic forces. Based on a single set of identical sites model, we obtained for the average number of binding sites a value of 3.4, which can be considered as the number of chitosan chains per nanoparticle. This value was confirmed by using a model based on the DLVO theory and fitting zeta potential measurements of magnetite/PLGA/chitosan nanoparticles. From the adjusted parameters, we found that an average number of chitosan molecules of 3.6 per nanoparticle are attached onto the surface of the PLGA matrix. Finally, we evaluated the effect of surface charge of nanoparticles on a membrane model of endothelial cells performed by a mixture of three phospholipids at the air-water interface. Different isotherms and adsorption curves show that cationic surface of charged nanoparticles strongly interact with the phospholipids mixture and these results can be the basis of future experiments to understand the nanoparticles- cell membrane interaction.
Krusenstjerna-Hafstrøm, Thomas; Madsen, Michael; Vendelbo, Mikkel H; Pedersen, Steen B; Christiansen, Jens S; Møller, Niels; Jessen, Niels; Jørgensen, Jens O L
GH induces acute insulin resistance in skeletal muscle in vivo, which in rodent models has been attributed to crosstalk between GH and insulin signaling pathways. Our objective was to characterize time course changes in signaling pathways for GH and insulin in human skeletal muscle in vivo following GH exposure in the presence and absence of an oral glucose load. Eight young men were studied in a single-blinded randomized crossover design on 3 occasions: 1) after an intravenous GH bolus 2) after an intravenous GH bolus plus an oral glucose load (OGTT), and 3) after intravenous saline plus OGTT. Muscle biopsies were taken at t = 0, 30, 60, and 120. Blood was sampled at frequent intervals for assessment of GH, insulin, glucose, and free fatty acids (FFA). GH increased AUC(glucose) after an OGTT (p<0.05) without significant changes in serum insulin levels. GH induced phosphorylation of STAT5 independently of the OGTT. Conversely, the OGTT induced acute phosphorylation of the insulin signaling proteins Akt (ser(473) and thr(308)), and AS160.The combination of OGTT and GH suppressed Akt activation, whereas the downstream expression of AS160 was amplified by GH. WE CONCLUDED THE FOLLOWING: 1) A physiological GH bolus activates STAT5 signaling pathways in skeletal muscle irrespective of ambient glucose and insulin levels 2) Insulin resistance induced by GH occurs without a distinct suppression of insulin signaling proteins 3) The accentuation of the glucose-stimulated activation of AS 160 by GH does however indicate a potential crosstalk between insulin and GH. ClinicalTrials.gov NCT00477997.
Peng, Qiang; Zhang, Zhi-Rong; Gong, Tao; Chen, Guo-Qiang; Sun, Xun
The application of poly(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx) for sustained and controlled delivery of hydrophilic insulin was made possible by preparing insulin phospholipid complex loaded biodegradable PHBHHx nanoparticles (INS-PLC-NPs). The INS-PLC-NPs produced by a solvent evaporation method showed a spherical shape with a mean particle size, zeta potential and entrapment efficiency of 186.2 nm, -38.4 mv and 89.73%, respectively. In vitro studies demonstrated that only 20% of insulin was released within 31 days with a burst release of 5.42% in the first 8 h. The hypoglycaemic effect in STZ induced diabetic rats lasted for more than 3 days after the subcutaneous injection of INS-PLC-NPs, which significantly prolonged the therapeutic effect compared with the administration of insulin solution. The pharmacological bioavailability (PA) of INS-PLC-NPs relative to insulin solution was over 350%, indicating that the bioavailability of insulin was significantly enhanced by INS-PLC-NPs. Therefore, the INS-PLC-NPs system is promising to serve as a long lasting insulin release formulation, by which the patient compliance can be enhanced significantly. This study also showed that phospholipid complex loaded biodegradable nanoparticles (PLC-NPs) have a great potential to be used as a sustained delivery system for hydrophilic proteins to be encapsulated in hydrophobic polymers.
Moghadam, Sajjad Khalili; Bahadoran, Zahra; Mirmiran, Parvin; Tohidi, Maryam; Azizi, Fereidoun
In the current study, we investigated the longitudinal association between dietary acid load and the risk of insulin resistance (IR) in the Tehranian adult population. This longitudinal study was conducted on 925 participants, aged 22~80 years old, in the framework of the third (2006~2008) and fourth (2009~2011) phases of the Tehran Lipid and Glucose Study. At baseline, the dietary intake of subjects was assessed using a validated semi-quantitative food frequency questionnaire, and the potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores were calculated at baseline. Fasting serum insulin and glucose were measured at baseline and again after a 3-year of follow-up; IR was defined according to optimal cut-off values. Multiple logistic regression models were used to estimate the risk of IR according to the PRAL and NEAP quartile categories. Mean age and body mass index of the participants were 40.3 years old of 26.4 kg/m2, respectively. Mean PRAL and NEAP scores were −11.2 and 35.6 mEq/d, respectively. After adjustment for potential confounders, compared to the lowest quartile of PRAL and NEAP, the highest quartile was accompanied with increased risk of IR [odds ratio (OR)=2.81, 95% confidence interval (CI)=1.32~5.97 and OR=2.18, 95% CI=1.03 ~4.61, respectively]. Our findings suggest that higher acidic dietary acid-base load, defined by higher PRAL and NEAP scores, may be a risk factor for the development of IR and related metabolic disorders. PMID:27390726
Wang, Chenhui; Yu, Changhui; Liu, Jiaxin; Teng, Lesheng; Sun, Fengying; Li, Youxin
The goal of this research is to prepare poly(cyclohexane-1,4 diyl acetone dimethylene ketal) (PCADK)/poly(D,L-lactide-co-glycolide) (PLGA) blend microspheres loaded with recombinant human growth hormone (rhGH). The effect of PCADK degradation products on the structural integrity, secondary and tertiary structure and pharmacodynamics of rhGH was evaluated by native-polyacrylamide gel electrophoresis (Native-PAGE), size-exclusion high performance liquid chromatography (SEC-HPLC), circular dichroism (CD), fluorescence spectroscopy and in hypophysectomized rat models. Compared with PLGA degradation products, rhGH was found to be more stable in the presence of PCADK degradation products. PCADK/PLGA blend microspheres were then prepared and the morphology, encapsulation efficiency, release behavior and rhGH stability were investigated. PCADK/PLGA microspheres had regular shapes and smooth surfaces when the proportion of PCADK was less than 50%. The late-releasable amount of rhGH in PCADK/PLGA microspheres was greater than that in PLGA microspheres. In addition, the PCADK/PLGA microspheres showed larger AUC and improved therapeutic effects on rats than PLGA microspheres. Furthermore, the pH inside the microspheres was detected by CLSM to explain the improved rhGH stability in the PCADK/PLGA microspheres. In conclusion, PCADK/PLGA blend microspheres showed potential to improve rhGH stability and the efficacy of sustained-release of rhGH compared with PLGA microspheres.
Wang, Xiaoyan; Zhang, Yu; Xue, Wei; Wang, Hong; Qiu, Xiaozhong; Liu, Zonghua
In this work, we explored the potential of thermo-sensitive PLGA-PEG-PLGA with sol-gel transition temperature around 32℃ as an intramuscular vaccine delivery system by using ovalbumin as a model antigen. First, in vitro release test showed that the PLGA-PEG-PLGA-deriving hydrogels could release ovalbumin in vitro in a more sustainable way. From fluorescence living imaging, 50-200 mg/mL of PLGA-PEG-PLGA formulations could release antigen in a sustainable manner in vivo, suggesting that the PLGA-PEG-PLGA hydrogel worked as an antigen-depot. Further, the sustainable antigen release from the PLGA-PEG-PLGA hydrogels increased antigen availability in the spleens of the immunized mice. The intramuscular immunization results showed that 50-200 mg/mL of PLGA-PEG-PLGA formulations promoted significantly more potent antigen-specific IgG immune response. In addition, 200 mg/mL of PLGA-PEG-PLGA formulation significantly enhanced the secretion of both Th1 and Th2 cytokines. From in vitro splenocyte proliferation assay, 50-200 mg/mL of PLGA-PEG-PLGA formulations all initiated significantly higher splenocyte activation. These results indicate that the thermo-sensitive and injectable PLGA-PEG-PLGA hydrogels (particularly, 200 mg/mL of PLGA-PEG-PLGA-based hydrogel) own promising potential as an intramuscular vaccine delivery system.
Vilos, Cristian; Velasquez, Luis A.; Rodas, Paula I.; Zepeda, Katherine; Bong, Soung-Jae; Herrera, Natalia; Cantin, Mario; Simon, Felipe; Constandil, Luis
Drug delivery systems based on polymeric microparticles represent an interesting field of development for the treatment of several infectious diseases for humans and animals. In this work, we developed PLGA microparticles loaded with ceftiofur (PLGA-cef), a third- generation cephalosporin that is used exclusively used in animals. PLGA-cef was prepared by the double emulsion w/o/w method, and exhibited a diameter in the range of 1.5–2.2 μm, and a negative ζ potential in the range of -35 to -55 mV. The loading yield of PLGA-cef was ~7% and encapsulation efficiency was approximately 40%. The pharmacokinetic study demonstrated a sustained release profile of ceftiofur for 20 days. PLGA-cef administrated in a single dose was more effective than ceftiofur non-encapsulated in rats challenged with S. Typhimurium. The in vivo toxicological evaluation showed that PLGA-cef did not affect the blood biochemical, hematological and hemostasis parameters. Overall, the PLGA-cef showed slow in vivo release profile, high antibacterial efficacy, and low toxicity. The results obtained supports the safe application of PLGA-cef as sustained release platform in the veterinary industry. PMID:25915043
Vilos, Cristian; Velasquez, Luis A; Rodas, Paula I; Zepeda, Katherine; Bong, Soung-Jae; Herrera, Natalia; Cantin, Mario; Simon, Felipe; Constandil, Luis
Drug delivery systems based on polymeric microparticles represent an interesting field of development for the treatment of several infectious diseases for humans and animals. In this work, we developed PLGA microparticles loaded with ceftiofur (PLGA-cef), a third- generation cephalosporin that is used exclusively used in animals. PLGA-cef was prepared by the double emulsion w/o/w method, and exhibited a diameter in the range of 1.5-2.2 μm, and a negative ζ potential in the range of -35 to -55 mV. The loading yield of PLGA-cef was ~7% and encapsulation efficiency was approximately 40%. The pharmacokinetic study demonstrated a sustained release profile of ceftiofur for 20 days. PLGA-cef administrated in a single dose was more effective than ceftiofur non-encapsulated in rats challenged with S. Typhimurium. The in vivo toxicological evaluation showed that PLGA-cef did not affect the blood biochemical, hematological and hemostasis parameters. Overall, the PLGA-cef showed slow in vivo release profile, high antibacterial efficacy, and low toxicity. The results obtained supports the safe application of PLGA-cef as sustained release platform in the veterinary industry.
Klupa, Tomasz; Benbenek-Klupa, Teresa; Matejko, Bartlomiej; Mrozinska, Sandra; Malecki, Maciej T
We aimed to estimate the impact of ingestion of a pure protein load on the glucose levels in T1DM patients treated with insulin pumps. We examined 10 T1DM patients (6 females, mean age-32.3 years, mean HbA1c-6.8%) treated with insulin pumps equipped with a continuous glucose monitoring system (CGMS). In Phase I, baseline insulin infusion was optimized to minimize the differences in fasting glucose levels to less than 30 mg/dL between any two time points between 9 a.m. and 3 p.m. In Phase II, the patients were exposed to single pure protein load. CGMS record was performed and the glucose pattern was defined for 6 hours of each phase. The maximal glucose level increment was similar for the entire duration of the fasting and the protein load test (26.6 versus 27.6 mg/dL, resp., P < 0.78). There was only a borderline difference in change between baseline versus 6th hour glucose (12.5 and 19.0 mg/dL, P = 0.04). Glucose variability, assessed by standard deviation of mean glucose levels, was 36.4 and 37.9 mg/dL, respectively (P = 0.01). The administration of a pure protein load does not seem to have a clinically significant impact on glucose levels in T1DM patients treated with insulin pumps.
Klupa, Tomasz; Benbenek-Klupa, Teresa; Matejko, Bartlomiej; Mrozinska, Sandra; Malecki, Maciej T.
We aimed to estimate the impact of ingestion of a pure protein load on the glucose levels in T1DM patients treated with insulin pumps. We examined 10 T1DM patients (6 females, mean age—32.3 years, mean HbA1c—6.8%) treated with insulin pumps equipped with a continuous glucose monitoring system (CGMS). In Phase I, baseline insulin infusion was optimized to minimize the differences in fasting glucose levels to less than 30 mg/dL between any two time points between 9 a.m. and 3 p.m. In Phase II, the patients were exposed to single pure protein load. CGMS record was performed and the glucose pattern was defined for 6 hours of each phase. The maximal glucose level increment was similar for the entire duration of the fasting and the protein load test (26.6 versus 27.6 mg/dL, resp., P < 0.78). There was only a borderline difference in change between baseline versus 6th hour glucose (12.5 and 19.0 mg/dL, P = 0.04). Glucose variability, assessed by standard deviation of mean glucose levels, was 36.4 and 37.9 mg/dL, respectively (P = 0.01). The administration of a pure protein load does not seem to have a clinically significant impact on glucose levels in T1DM patients treated with insulin pumps. PMID:25767510
The manipulation of organic materials--cells, tissues, and even living organisms--offers many exciting possibilities for the future from organic computers to improved aquaculture. Commercial researchers are using the microgravity environment to produce large near perfect protein crystals Research on insulin has yielded crystals that far surpass the quality of insulin crystals grown on the ground. Using these crystals industry partners are working to develop new and improved treatments for diabetes. Other researchers are exploring the possibility of producing antibiotics using plant cell cultures which could lead to both orbital production and the improvement of ground-based antibiotic production.
Müller, M; Vörös, J; Csúcs, G; Walter, E; Danuser, G; Merkle, H P; Spencer, N D; Textor, M
Microspheres made of poly(lactic-co-glycolic acid) (PLGA) are biocompatible and biodegradable, rendering them a promising tool in the context of drug delivery. However, nonspecific adsorption of plasma proteins on PLGA micro- and nanospheres is a main limitation of drug targeting. Poly(L-lysine)-g-poly(ethylene glycol) (PLL-g-PEG), physisorbed on flat metal oxide surfaces, has previously been shown to suppress protein adsorption drastically. The goal of our work was to characterize the efficiency of the protein repellent character of PLL-g-PEG on PLGA microspheres and to show the feasibility of introducing functional groups on the PLGA microspheres via functionalized PLL-g-PEG. To quantify the adsorbed amount of protein, a semiquantitative method that uses confocal laser scanning microscopy (CLSM) was applied. The first part of the experiment confirms the feasibility of introducing specific functional groups on PLL-g-PEG-coated PLGA microspheres. In the second part of the experiment, PLL-g-PEG-coated PLGA microspheres show a drastic decrease of adsorbed proteins by two orders of magnitude in comparison to uncoated PLGA microspheres. Low protein-binding, functionalizable microspheres provide a fundamental basis for the design of drug delivery and biosensor systems. Copyright 2003 Wiley Periodicals, Inc.
Tang, Xiaolong; Liang, Yong; Liu, Xinkuang; Zhou, Shuping; Liu, Liang; Zhang, Fujina; Xie, Chunmei; Cai, Shuyu; Wei, Jia; Zhu, Yongqiang; Hou, Wei
Activating HIV-1 proviruses in latent reservoirs combined with inhibiting viral spread might be an effective anti-HIV therapeutic strategy. Active specific delivery of therapeutic drugs into cells harboring latent HIV, without the use of viral vectors, is a critical challenge to this objective. In this study, nanoparticles of poly(lactic-co-glycolic acid)-polyethylene glycol diblock copolymers conjugated with anti-CD45RO antibody and loaded with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) and/or protease inhibitor nelfinavir (Nel) were tested for activity against latent virus in vitro. Nanoparticles loaded with SAHA, Nel, and SAHA + Nel were characterized in terms of size, surface morphology, zeta potential, entrapment efficiency, drug release, and toxicity to ACH-2 cells. We show that SAHA- and SAHA + Nel-loaded nanoparticles can target latently infected CD4+ T-cells and stimulate virus production. Moreover, nanoparticles loaded with SAHA + NEL were capable of both activating latent virus and inhibiting viral spread. Taken together, these data demonstrate the potential of this novel reagent for targeting and eliminating latent HIV reservoirs.
Fu, Xudong; Zeng, Huilin; Guo, Jiaping; Liu, Hong; Shi, Zhen; Chen, Huhai; Li, Dezong; Xie, Xiangyang; Kuang, Changchun
Postoperative pain is a complex physiological response to disease and tissue injury. Moderate-to-severe pain typically occurs within 48 h after surgery. Amino amide local anesthetics are widely applied to manage postoperative pain, and they have high efficacy, a low risk for addiction and limited side effects. However, these anesthetics also have short half-lives, often necessitating continuous injection to obtain satisfactory pain relief. In the current work, we used a poly(lactic-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-PLGA (PLGA-PEG-PLGA) temperature-sensitive gel to deliver a local anesthetic, ropivacaine hydrochloride (RP), to prolong its analgesic effect. We investigated the influence of polymer and drug concentration on gelation temperature and the in vitro drug release rate from the temperature-sensitive gel. RP-loaded PLGA-PEG-PLGA solution is a liquid at room temperature and forms a gel at temperatures slightly lower than body temperature. With regard to the gel's drug release rate, 37.5, 51.3 and 72.6% of RP was released at 12, 24 and 48 h, respectively. This in vitro drug release profile conformed to the Higuchi equation. To assess pain control efficacy when using the gel, we evaluated the mechanical paw withdrawal reflex threshold, thermal pain threshold and incision cumulative pain scores in a rat incisional model. The results showed that the anti-pain effect of a single injection of RP-loaded gel at the incision site lasted for 48 h, which is significantly longer than the effect produced by injection of RP solution alone. The use of RP-loaded thermosensitive gels could provide a promising method for managing postoperative pain.
Chen, Y; Wang, F; Benson, H A E
The objective of this study was to examine formulation factors that influence the incorporation of the hydrophilic peptide dalargin into poly(D, L-lactic-co-glycolic acid) (PLGA) and methoxy-polyethylene glycol (mPEG)-PLGA nanoparticles. In particular, the effect of ionic additives and nanoparticle method of preparation on the incorporation of dalargin and resultant nanoparticle properties was investigated. Biodegradable nanoparticles were prepared from mPEG-PLGA and PLGA by both solvent evaporation and solvent diffusion methods with inclusion of ionic additives of dextran sulphate (DS), sulfobutyl ether-beta-cyclodextrin (SB-CD), or sodium dodecyl sulfate (SDS). The resultant nanoparticles were analyzed for their mean particle size and size distribution, zeta-potential, peptide loading, yield, and morphology. The inclusion of ionic additives in the nanoparticle formulation significantly influenced dalargin entrapment efficiency (EE). For example, with the PLGA/SDS formulation EE increased from 13.3% to 91.2% and from 4.1% to 68.6% with the solvent diffusion and evaporation methods, respectively. The inclusion of ionic surfactant SDS has also lead to the formation of smaller size of nanoparticles. Isothermal titration microcalorimetry revealed a strong interaction between dalargin and DS, medium level interaction with SDS, and weak interaction with SB-CD. The results of this study suggest that a strong ionic interaction between peptides and additives may lead to enhanced peptide incorporation but also increased particle size. Intermediate ionic interaction, especially when it is associated with the formation of reversed micelles in a hydrophobic polymer solution, could be used to enhance the incorporation of hydrophilic peptides in PLGA and mPEG-PLGA nanoparticles. (c) 2008 Wiley Periodicals, Inc.
Luo, Yue Yuan; Xiong, Xiang Yuan; Tian, Yuan; Li, Zi Ling; Gong, Yan Chun; Li, Yu Ping
Currently, repeated routine subcutaneous injections of insulin are the standard treatment for insulin-dependent diabetic patients. However, patients' poor compliance for injections often fails to achieve the stable concentration of blood glucose. As a protein drug, the oral bioavailability of insulin is low due to many physiological reasons. Several carriers, such as macromolecules and liposomes have been used to deliver drugs in vivo. In this review article, the gastrointestinal barriers of oral insulin administration are described. Strategies for increasing the bioavailability of oral insulin, such absorption enhancers, enzyme inhibitors, enteric coatings are also introduced. The potential absorption mechanisms of insulin-loaded nanoparticles across the intestinal epithelium, including intestinal lymphatic route, transcellular route and paracellular route are discussed in this review. Natural polymers, such as chitosan and its derivates, alginate derivatives, γ-PGA-based materials and starch-based nanoparticles have been exploited for oral insulin delivery; synthetic polymers, such as PLGA, PLA, PCL and PEA have also been developed for oral administration of insulin. This review focuses on recent advances in using biodegradable natural and synthetic polymers for oral insulin delivery along with their future prospects.
Lei, Fan; Si, Ting; Luo, Xisheng; Xu, Ronald X.
Curcumin-loaded PLGA microcapsules are fabricated by a liquid-driving coaxial flow focusing device. In the process, a stable coaxial cone-jet configuration is formed under the action of a coflowing liquid stream and the coaxial liquid jet eventually breaks up into microcapsules because of flow instability. This process can be well controlled by adjusting the flow rates of three phases including the driving PVA water solution, the outer PLGA ethyl acetate solution and the inner curcumin propylene glycol solution. Confocal and SEM imaging methods clearly indicate the core-shell structure of the resultant microcapsules. The encapsulation rate of curcumin in PLGA is measured to be more than 70%, which is much higher than the tranditional methods such as emulsion. The size distribution of resultant microcapsules under different conditions is presented and compared. An in vitro release simulation platform is further developed to verify the feasibility and reliability of the method.
Shen, Yu-Bin; Du, Zhe; Tang, Chuan; Guan, Yi-Xin; Yao, Shan-Jing
Supercritical fluid assisted atomization introduced by a hydrodynamic cavitation mixer (SAA-HCM) was proposed as a green technique to fabricate insulin-loaded dry powders for inhalation administration. N-trimethyl chitosan (TMC), a polymeric mucoadhesive absorption enhancer, was synthesized and successfully micronized from aqueous solution using SAA-HCM. The prepared well-defined spherical TMC microparticles with preserved structure and thermal stability were potential carriers for delivery of proteins. Then, insulin-loaded TMC microparticles with high loading efficiency were coprecipitated from aqueous solutions using SAA-HCM without use of any organic solvents. The polymer/protein ratio revealed to be a factor influencing the particle morphology, and non-coalescing composite microparticles in amorphous state mainly ranging from 1μm to 5μm could be obtained in this work. Aerodynamic properties were assessed by next generation impactor (NGI) and the mass median aerodynamic diameter (MMAD) lied inside the inhalable range of 1-5μm, while fine particle fraction (FPF) reached above 60%. The structural integrity of encapsulated insulin was confirmed by HPLC, circular dichroism and fluorescence spectroscopy. In vivo study demonstrated that TMC could enhance the absorption and bioavailability of the pulmonarily administered insulin formulation for SD rats. These results suggest that TMC microparticles could be efficiently prepared as a promising vehicle for drug delivery, and SAA-HCM is a promising technique to prepare inhalable polymer/protein composite dry powders. Copyright © 2016 Elsevier B.V. All rights reserved.
Yang, Xiaoxia; Ji, Xiaoqing; Shi, Chunhuan; Liu, Jing; Wang, Haiyang; Luan, Yuxia
The amantadine drug and oleic acid surfactant are used to form amantadine-based ion pair amphiphiles based on proton transfer reaction between the drug and the surfactant molecules. The ion pair amphiphiles are characterized by 1H-nuclear magnetic resonance, Fourier transform infrared spectroscopy, and X-ray diffraction. Self-assembly properties of amantadine-based ion pair amphiphiles are studied by surface tension determination, transmission electron microscopy, zeta potential, and dynamic light scattering. The aggregation behavior studies indicate that the as-prepared ion pair amphiphiles can self-assemble into vesicles with the size of 200-300 nm in aqueous solution. The drug release results show that the amantadine release rate could be well controlled by incorporating the amantadine-based ion pair vesicles in poly (lactic-co-glycolic acid)-poly (ethylene glycol)-poly (lactic-co-glycolic acid) (PLGA-PEG-PLGA) copolymer hydrogel. The drug release from the AT-OA vesicle-loaded PLGA-PEG-PLGA hydrogel is significantly inhibited in comparison with the AT-loaded PLGA-PEG-PLGA hydrogel. The present work thus demonstrates that the vesicle-loaded hydrogel is a good candidate for the drug delivery system with long-term controlled drug release behavior.
Pascual-Gil, S; Simón-Yarza, T; Garbayo, E; Prosper, F; Blanco-Prieto, M J
The growth factor neuregulin (NRG) is one of the most promising candidates in protein therapy as potential treatment for myocardial infarction (MI). In the last few years, biomaterial based delivery systems, such as polymeric microparticles (MPs) made of poly(lactic co glycolic acid) and polyethylene glycol (PLGA and PEG-PLGA MPs), have improved the efficacy of protein therapy in preclinical studies. However, no cardiac treatment based on MPs has yet been commercialized since this is a relatively new field and total characterization of polymeric MPs remains mandatory before they reach the clinical arena. Therefore, the objective of this study was to characterize the in vivo release, bioactivity and biodegradation of PLGA and PEG-PLGA MPs loaded with biotinylated NRG in a rat model of MI. The effect of PEGylation in the clearance of the particles from the cardiac tissue was also evaluated. Interestingly, MPs were detected in the cardiac tissue for up to 12 weeks after administration. In vivo release analysis showed that bNRG was released in a controlled manner throughout the twelve week study. Moreover, the biological cardiomyocyte receptor (ErbB4) for NRG was detected in its activated form only in those animals treated with bNRG loaded MPs. On the other hand, the PEGylation strategy was effective in diminishing phagocytosis of these MPs compared to noncoated MPs in the long term (12 weeks after injection). Taking all this together, we report new evidence in favor of the use of polymeric PLGA and PEG-PLGA MPs as delivery systems for treating MI, which could be soon included in clinical trials.
Tamir, I; Grant, D B; Fosbrooke, A S; Segall, M M; Lloyd, J K
Analysis of serum free fatty acids by gas-liquid chromatography showed high proportions (27-57%) of octanoic acid for up to 4 hr after the ingestion of a single oral load of medium-chain triglyceride (approximately 1 g/kg body weight) in four volunteers. The effects of a medium-chain triglyceride load on the concentrations of plasma free long-chain fatty acids, plasma glucose, serum insulin, and serum triglyceride were observed and compared with the effects of a glucose load. A rapid fall in the free long-chain fatty acids followed both loads but only a small rise in serum insulin was observed after medium-chain triglyceride. The fall in free long-chain fatty acids following ingestion of medium-chain triglyceride cannot therefore be caused mainly by the release of insulin and may be due to a direct action on adipose tissue. No medium-chain fatty acids were detected in the serum triglyceride after ingestion of medium-chain triglyceride, but there was a small but significant increase in the percentage of hexadecenoic acid in this fraction.
Tafaghodi, Mohsen; Khamesipour, Ali; Jaafari, Mahmoud R
Various adjuvants and delivery systems have been evaluated for increasing the protective immune responses against leishmaniasis and mostly have been shown not to be effective enough. In this study, poly(D,L-lactide-co-glycolide) (PLGA) nanospheres as an antigen delivery system and CpG-ODN as an immunoadjuvant have been used for the first time to enhance the immune response against autoclaved Leishmania major (ALM). PLGA nanospheres were prepared by a double-emulsion (W/O/W) technique. Particulate characteristics were studied by scanning electron microscopy and particle size analysis. Mean diameter of ALM + CpG-ODN-loaded nanospheres was 300 ± 128 nm. BALB/c mice were immunized three times in 3-week intervals using ALM plus CpG-ODN-loaded nanospheres [(ALM + CpG-ODN)(PLGA)], ALM encapsulated PLGA nanospheres [(ALM)(PLGA)], (ALM)(PLGA) + CpG, ALM + CpG, ALM alone, or phosphate buffer solution (PBS). The intensity of infection induced by L. major challenge was assessed by measuring size of footpad swelling. The strongest protection, showed by significantly (P<0.05) smaller footpad, was observed in mice immunized with (ALM + CpG-ODN)(PLGA). The (ALM)(PLGA), (ALM)(PLGA) + CpG, and ALM + CpG were also showed a significantly (P<0.05) smaller footpad swelling compared to the groups received either PBS or ALM alone. The mice immunized with (ALM + CpG-ODN)(PLGA), (ALM)(PLGA) + CpG, and ALM + CpG showed the highest IgG2a/IgG1 ratio, interferon-γ production, and lowest interleukin-4 production compared to the other groups. It is concluded that when both PLGA nanospheres and CpG-ODN adjuvants were used simultaneously, it induce stronger immune response and enhance protection rate against Leishmania infection.
Li, Ping; Tan, Angel; Prestidge, Clive A; Nielsen, Hanne Mørck; Müllertz, Anette
This study aims at evaluating the combination of self-nanoemulsifying drug delivery systems (SNEDDS) and enteric-coated capsules as a potential delivery strategy for oral delivery of insulin. The SNEDDS preconcentrates, loaded with insulin-phospholipid complex at different levels (0, 2.5 and 10% w/w), were readily dispersed in water to form nanoemulsions of 35 nm and vesicles of 300 nm. The association efficiency of non-complexed insulin in the dispersed SNEDDS was 18.6%, and was increased to 73.1% for insulin-phospholipid complex (at 10% loading level). The morphology of the dispersed SNEDDS changed from nanoemulsion droplets to vesicular structures with increasing complex loading levels. A pH-dependent insulin release profile was observed for SNEDDS filled into capsules coated with the enteric polymer, Eudragit(®) L100. Using a Caco-2 cell model, it was observed that the transport of insulin was enhanced by factors of 7.7- and 9.3- for SNEDDS loaded with 2.5 and 10% complex, respectively. In healthy fasted rats, administration of SNEDDS (10% complex) filled in enteric-coated capsules produced a 2.7-fold and 3.4-fold enhancement in the relative bioavailability and glucose reduction, respectively. This study shows the effectiveness of combining SNEDDS (loaded with insulin-phospholipid complex) with enteric-coated capsules for enhancing the oral absorption and efficacy of insulin.
Abrego, Guadalupe; Alvarado, Helen; Souto, Eliana B; Guevara, Bessy; Bellowa, Lyda Halbaut; Garduño, Maria Luisa; Garcia, María Luisa; Calpena, Ana C
Pranoprofen (PF)-loaded nanoparticles (PF-F1NPs and PF-F2NPs) have been formulated into blank hydrogels (HG_PF-F1NPs and HG_PF-F1NPs) or into hydrogels composed of 3% azone (HG_PF-F1NPs-Azone and HG_PF-F2NPs-Azone), as innovative strategy to improve the biopharmaceutical profile of the selected non-steroidal anti-inflammatory drug (Pranoprofen, PF) for topical application. The purpose of this approach has been to increase the contact of PF with the skin, improve its retention in deeper layers, thus enhancing its anti-inflammatory and analgesic effects. The physicochemical characterization of the developed hydrogels showed a non-Newtonian behaviour, typical of semi-solid formulations for skin administration, with sustained release profile. The results obtained from ex vivo skin human permeation and in vivo anti-inflammatory efficacy studies suggest that topical application of HG_PF-F2NPs has been more effective in the treatment of oedema on the skin' surface in comparison to other hydrogels. No signs of skin irritancy have been detected for all the semi-solid formulations containing 0% or 3% azone. Copyright © 2016 Elsevier B.V. All rights reserved.
Bishayee, Kausik; Khuda-Bukhsh, Anisur Rahman; Huh, Sung-Oh
Controlled release of medications remains the most convenient way to deliver drugs. In this study, we precipitated gold nanoparticles with quercetin. We loaded gold-quercetin into poly(DL-lactide-co-glycolide) nanoparticles (NQ) and tested the biological activity of NQ on HepG2 hepatocarcinoma cells to acquire the sustained release property. We determined by circular dichroism spectroscopy that NQ effectively caused conformational changes in DNA and modulated different proteins related to epigenetic modifications and cell cycle control. The mitochondrial membrane potential (MMP), reactive oxygen species (ROS), cell cycle, apoptosis, DNA damage, and caspase 3 activity were analyzed by flow cytometry, and the expression profiles of different anti- and pro-apoptotic as well as epigenetic signals were studied by immunoblotting. A cytotoxicity assay indicated that NQ preferentially killed cancer cells, compared to normal cells. NQ interacted with HepG2 cell DNA and reduced histone deacetylases to control cell proliferation and arrest the cell cycle at the sub-G stage. Activities of cell cycle-related proteins, such as p21(WAF), cdk1, and pAkt, were modulated. NQ induced apoptosis in HepG2 cells by activating p53-ROS crosstalk and induces epigenetic modifications leading to inhibited proliferation and cell cycle arrest.
Andrade-Carrera, Berenice; Clares, Beatriz; Noé, Véronique; Mallandrich, Mireia; Calpena, Ana C; García, María Luisa; Garduño-Ramírez, María Luisa
The search for new alternatives for the prevention and treatment of cancer is extremely important to minimize human mortality. Natural products are an alternative to chemical drugs, since they are a source of many potential compounds with anticancer properties. In the present study, the (2S)-5,7-dihydroxy-6-prenylflavanone (semi-systematic name), also called (2S)-5,7-dihydroxy-6-(3-methyl-2-buten-1-yl)-2-phenyl-2,3-dihydro-4H-1-Benzopyran-4-one (CAS Name registered) (1) was isolated from Eysenhardtia platycarpa leaves. This flavanone 1 was considered as the lead compound to generate new cytotoxic derivatives 1a, 1b, 1c and 1d. These compounds 1, 1a, 1b, 1c, and 1d were then loaded in nanosized drug delivery systems such as polymeric nanoparticles (NPs). Small homogeneous spherical shaped NPs were obtained. Cytotoxic activity of free compounds 1, 1a, 1b, 1c, and 1d and encapsulated in polymeric NPs (NPs1, NPs1a, NPs1b, NPs1c and NPs1d) were evaluated against the pancreatic cancer cell line MiaPaCa-2. The obtained results demonstrated that NPs1a and NPs1b exhibited optimal cytotoxicity, and an even higher improvement of the cytotoxic efficacy was exhibited with the encapsulation of 1a. Based on these results, NPs1a were proposed as promising anticancer agent candidates.
Cetin, Meltem; Aktas, Mustafa Sinan; Vural, Imran; Ozturk, Murat
The main objective of this study was to prepare salmon calcitonin (sCT)-loaded Eudragit®RSPO, Eudragit®L100 and Eudragit®-poly(lactic-co-glycolic acid) blend nanoparticles for in vitro and in vivo evaluation as an oral drug delivery system. The prepared nanoparticles ranged in size from 179.7 to 308.9 nm with a polydispersity index between 0.051 and 2.75, and had surface charges ~ -11 to +6 mV. Efficient sCT encapsulation and release was observed with all the nanoparticle formulations. The polymer type was an important factor that influenced the release characteristics and the in vivo hypocalcemic effect. Nanoparticle formulations were also prepared with sodium taurodeoxycholate (NaTDC) and characterized. No statistically significant difference was noted between the hypocalcemic effect of any of the nanoparticle formulations with and without NaTDC (p > 0.05). The use of Eudragit®RSPO nanoparticles appears to be a potential approach for the oral delivery of sCT.
Nimptsch, K; Kenfield, S; Jensen, M K; Stampfer, M J; Franz, M; Sampson, L; Brand-Miller, J C; Willett, W C; Giovannucci, E
Insulin may play a role in prostate cancer tumorigenesis. Postprandial blood glucose and insulin responses of foods depend importantly on the carbohydrate quality and quantity, represented by glycemic index (GI), glycemic load (GL), fiber and whole-grain content, but are also influenced by intake of protein and other characteristics. The recently developed insulin index (II) quantifies the postprandial insulin secretion, also taking into account these additional characteristics. We investigated the association between dietary GI, GL, II, fiber, and whole grains and risk of total prostate cancer (n = 5,112) and subgroups of prostate cancer as defined by stage or grade in 49,934 male participants of the Health Professionals Follow-up Study. Multivariate adjusted hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated using Cox proportional hazards regression. Dietary GI, GL, II, or fiber was not associated with risk of total or subgroups of prostate cancer. We observed a positive association between dietary intake of whole grains and total prostate cancer (HR highest versus lowest quintile 1.13, 95% CI 1.03-1.24), which was attenuated after restriction to PSA-screened participants (HR 1.03, 95% CI 0.91-1.17). These results suggest that long-term exposure to a diet with a high insulin response does not affect prostate cancer incidence.
Nan, Kaihui; Ma, Feiyan; Hou, Huiyuan; Freeman, William R.; Sailor, Michael J.; Cheng, Lingyun
A water-soluble anthracycline antibiotic drug (daunorubicin, DNR) was loaded into oxidized porous silicon (pSiO2) microparticles and then encapsulated with a layer of polymer (poly lactide-co-glycolide, PLGA) to investigate their synergistic effects in control of DNR release. Similarly fabricated PLGA-DNR microspheres without pSiO2, and pSiO2 microparticles without PLGA were used as control particles. The composite microparticles synthesized by a solid-in-oil-in-water (S/O/W) emulsion method have mean diameters of 52.33±16.37 μm for PLGA-pSiO2_21/40-DNR and the mean diameter of 49.31±8.87 μm for PLGA-pSiO2_6/20-DNR. The mean size, 26.00±8 μm, of PLGA-DNR was significantly smaller, compared with the other two (p<0.0001). Optical microscopy revealed that PLGA-pSiO2-DNR microsphere contained multiple pSiO2 particles. In vitro release experiments determined that control PLGA-DNR microspheres completely released DNR within 38 days and control pSiO2-DNR microparticles (with no PLGA coating) released DNR within 14 days, while the PLGA-pSiO2-DNR microspheres released DNR for 74 days. Temporal release profiles of DNR from PLGA-pSiO2 composite particles indicated that both PLGA and pSiO2 contribute to the sustained release of the payload. The PLGA-pSiO2 composite displayed a more constant rate of DNR release than the pSiO2 control formulation, and it displayed a significantly slower release of DNR than either the PLGA or pSiO2 formulations. We conclude that this system may be useful in managing unwanted ocular proliferation when formulated with anti-proliferation compounds such as DNR. PMID:24793657
Déat-Lainé, Emmanuelle; Hoffart, Valérie; Cardot, Jean-Michel; Subirade, Muriel; Beyssac, Eric
Insulin was encapsulated into microparticles (MP) made of denaturized whey proteins (WP) and alginate (ALG) using an extrusion/cold gelation process with calcium ions. High encapsulation efficiency of 85% was obtained. Influence of insulin on polymeric viscosity and on microparticle behavior was evaluated. Insulin seemed to interact with WP chains by non covalent binding and steric hindrance. This influence was balanced by ALG addition. Nevertheless, insulin was released rapidly by diffusion at both acidic and intestinal dissolution media. Despite this fast in vitro release, WP/ALG MP showed an important enzymatic inhibition effect on trypsin and alpha-chymotrypsin. Thus, WP/ALG MP contributed to an effective insulin protection towards enzymatic degradation. The aforementioned results suggested that WP based microparticles are a promising carrier for improving oral delivery of insulin.
Wang, Jun-Teng; Lin, Dong-Hai; Qin, Li-Fang; Wen, Zhen; Guo, Gui-Ping
To investigate the effects of particle size, mPEG molecular weight, coating density and zeta potential of monomethoxyl poly(ethylene glycol)-poly(lactic-co-glycolic acid) (mPEG-PLGA) nanoparticles on their transportation across the rat nasal mucosa, mPEG-PLGA-NPs with different mPEG molecular weights (M(r) 1 000, 2 000) and coating density (0, 5%, 10%, 15%) and chitosan coated PLGA-NP, which loaded coumarin-6 as fluorescent marker, were prepared with the nanoprecipitation method and emulsion-solvent evaporation method, and determine their particle size, zeta potential, the efficiency of fluorescent labeling, in vitro leakage rate and the stability with the lysozyme were determined. The effects of physical and chemical properties on the transmucosal transport of the fluorescent nanoparticles were investigated by confocal laser scanning microscopy (CLSM). The result showed that the size of nanoparticles prepared with nanoprecipitation method varied between 120 and 200 nm; the size of nanoparticles prepared with emulsion-solvent evaporation method varied between 420 and 450 nm. Nanoparticles dispersed uniformly; the zeta potential of PLGA-NPs was negative; mPEG-PLGA-NPs was close to neutral; chitosan coated PLGA-NPs was positive; and the efficiency of fluorescent labeling were higher than 80%. In vitro leak was less than 5% within 4 h and nanoparticles were basically stable with lysozyme. The CLSM results show that the transportation efficiency of mPEG-PLGA-NPs with a high PEG coating density and high mPEG molecular weight was significantly higher than that of uncoated PLGA nanoparticles and also that of chitosan coated PLGA-NPs (P < 0.05). The hydrophilcity, zeta potential and particle size of nanoparticles play important roles on the efficiency of mPEG-PLGA nanoparticles to transport across the rat nasal mucosa.
D'Souza, Susan; Faraj, Jabar A.; Giovagnoli, Stefano; DeLuca, Patrick P.
The aim of this study was to design and evaluate biodegradable PLGA microspheres for sustained delivery of Risperidone, with an eventual goal of avoiding combination therapy for the treatment of schizophrenia. Two PLGA copolymers (50 : 50 and 75 : 25) were used to prepare four microsphere formulations of Risperidone. The microspheres were characterized by several in vitro techniques. In vivo studies in male Sprague-Dawley rats at 20 and 40 mg/kg doses revealed that all formulations exhibited an initial burst followed by sustained release of the active moiety. Additionally, formulations prepared with 50 : 50 PLGA had a shorter duration of action and lower cumulative AUC levels than the 75 : 25 PLGA microspheres. A simulation of multiple dosing at weekly or 15-day regimen revealed pulsatile behavior for all formulations with steady state being achieved by the second dose. Overall, the clinical use of Formulations A, B, C, or D will eliminate the need for combination oral therapy and reduce time to achieve steady state, with a smaller washout period upon cessation of therapy. Results of this study prove the suitability of using PLGA copolymers of varying composition and molecular weight to develop sustained release formulations that can tailor in vivo behavior and enhance pharmacological effectiveness of the drug. PMID:24616812
Background Poly lactic-co-glycolic acid (PLGA) based nanoparticles are considered to be a promising drug carrier in tumor targeting but suffer from the high level of opsonization by reticuloendothelial system due to their hydrophobic structure. As a result surface modification of these nanoparticles has been widely studied as an essential step in their development. Among various surface modifications, human serum albumin (HSA) possesses advantages including small size, hydrophilic surface and accumulation in leaky vasculature of tumors through passive targeting and a probable active transport into tumor tissues. Methods PLGA nanoparticles of docetaxel were prepared by emulsification evaporation method and were surface conjugated with human serum albumin. Fourier transform infrared spectrum was used to confirm the conjugation reaction where nuclear magnetic resonance was utilized for conjugation ratio determination. In addition, transmission electron microscopy showed two different contrast media in conjugated nanoparticles. Furthermore, cytotoxicity of free docetaxel, unconjugated and conjugated PLGA nanoparticles was studied in HepG2 cells. Results Size, zeta potential and drug loading of PLGA nanoparticles were about 199 nm, −11.07 mV, and 4%, respectively where size, zeta potential and drug loading of conjugated nanoparticles were found to be 204 nm, −5.6 mV and 3.6% respectively. Conjugated nanoparticles represented a three-phasic release pattern with a 20% burst effect for docetaxel on the first day. Cytotoxicity experiment showed that the IC50 of HSA conjugated PLGA nanoparticles (5.4 μg) was significantly lower than both free docetaxel (20.2 μg) and unconjugated PLGA nanoparticles (6.2 μg). Conclusion In conclusion surface modification of PLGA nanoparticles through HSA conjugation results in more cytotoxicity against tumor cell lines compared with free docetaxel and unconjugated PLGA nanoparticles. Albumin conjugated PLGA nanoparticles may
Desai, Kashappa-Goud H.; Kadous, Samer; Schwendeman, Steven P.
Purpose To investigate the effect of γ-irradiation of poly(lactic-co-glycolic acid) (PLGA)/Al(OH)3/0 or 5 wt% diethyl phthalate (DEP) microspheres for active self-healing encapsulation of vaccine antigens. Methods Microspheres were irradiated with 60Co at 2.5 and 1.8 MRad and 0.37 and 0.20 MRad/h. Encapsulation of tetanus toxoid (TT) was achieved by mixing Al(OH)3-PLGA microspheres with TT solution at 10-38°C. Electron paramagnetic resonance (EPR) spectroscopy was used to examine free radical formation. Glass transition temperature (Tg) and molecular weight of PLGA was measured by differential scanning calorimetry and gel permeation chromatography, respectively. Loading and release of TT were examined by modified Bradford, amino acid analysis, and ELISA assays. Results EPR spectroscopy results indicated absence of free radicals in PLGA microspheres after γ-irradiation. Antigen-sorbing capacity, encapsulation efficiency, and Tg of the polymer were also not adversely affected. When DEP-loaded microspheres were irradiated at 0.2 MRad/h, some PLGA pores healed during irradiation and PLGA healing during encapsulation was suppressed. The molecular weight of PLGA was slightly reduced when DEP-loaded microspheres were irradiated at the same dose rate. These trends were not observed at 0.37 MRad/h. Gamma irradiation slightly increased TT initial burst release. Apart from the slightly higher polymer molecular weight decline caused by higher irradiation dose in case of DEP-loaded microspheres, the small increase in total irradiation dose from 1.8 to 2.5 MRad had insignificant effect on the polymer and microspheres properties analyzed. Conclusion Gamma irradiation is a plausible approach to provide a terminally sterilized, self-healing encapsulation PLGA excipient for vaccine delivery. PMID:23515830
Sun, Deqing; Xue, Aiying; Zhang, Bin; Lou, Haiyan; Shi, Huanying; Zhang, Xiumei
Acetylpuerarin (AP) is an acetylated derivative of puerarin (PUE). The study aimed to prepare polysorbate 80-coated poly(lactic-co-glycolic acid) (PLGA) nanoparticles to improve the permeability of AP across the blood-brain barrier (BBB) and enhance its brain-protective effects. AP-loaded PLGA nanoparticles (AP-PLGA-NPs) were prepared using a solvent diffusion methodology. The NPs were characterized. The pharmacokinetics, tissue distributions and brain-protective effects of AP-PLGA-NPs were evaluated in animals. AP-PLGA-NPs were successfully prepared with a mean particle size of 145.0 nm and a zeta potential of -14.81 mV. The in-vitro release of AP from the PLGA-NPs showed a biphasic release profile. AP was metabolized into PUE in rats. The AUC0-∞ values of AP and PUE for AP-PLGA-NPs were 2.90- and 2.29-fold as great as those for AP solution, respectively. The values of the relative targeting efficiency in the brain were 2.40 and 2.58 for AP and PUE, and the ratios of peak concentration were 1.91 and 1.89 for AP and PUE, respectively. Compared with the crude drug, AP-PLGA-NPs showed better brain-protective effects in rats. Polysorbate 80-coated PLGA-NPs can improve the permeability of AP cross the BBB and enhance its brain-protective effects in rats. © 2015 Royal Pharmaceutical Society.
Brownley, Kimberly A; Heymen, Steve; Hinderliter, Alan L; Galanko, Joseph; Macintosh, Beth
Alterations in appetite hormones favoring increased postprandial satiety have been implicated in both the glycemic control and potential weight-loss benefits of a low-glycemic diet. Racial differences exist in dietary glycemic load and appetite hormone concentrations. This study examined the impact of glycemic load on appetite hormones in 20 black women [10 normal weight, BMI = 22.8 ± 1.42 (mean ± SD); 10 obese, BMI = 35.1 ± 2.77] and 20 white women (10 normal weight, BMI = 22.9 ± 1.45; 10 obese, BMI = 34.3 ± 2.77). Each woman completed two 4.5-d weight-maintenance, mixed-macronutrient, high-glycemic vs. low-glycemic load diets that concluded with a test meal of identical composition. Blood samples collected before and serially for 3 h after each test meal were assayed for plasma ghrelin and serum insulin and glucose concentrations. Compared with the high-glycemic load meal, the low-glycemic load meal was associated with lower insulin(AUC) (P = 0.02), glucose(AUC) (P = 0.01), and urge to eat ratings (P = 0.05) but with higher ghrelin(AUC) (P = 0.008). These results suggest the satiating effect of a low-glycemic load meal is not directly linked to enhanced postprandial suppression of ghrelin. Notably, these effects were significant among white but not black women, suggesting that black women may be less sensitive than white women to the glucoregulatory effects of a low-glycemic load. These findings add to a growing literature demonstrating racial differences in postprandial appetite hormone responses. If reproducible, these findings have implications for individualized diet prescription for the purposes of glucose or weight control in women.
Xi, Juqun; Da, Lanyue; Yang, Changshui; Chen, Rui; Gao, Lizeng; Fan, Lei; Han, Jie
Nanoparticle drug delivery carriers, which can implement high performances of multi-functions, are of great interest, especially for improving cancer therapy. Herein, we reported a new approach to construct Mn(2+)-coordinated doxorubicin (DOX)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles as a platform for synergistic chemo-photothermal tumor therapy. DOX-loaded PLGA (DOX/PLGA) nanoparticles were first synthesized through a double emulsion-solvent evaporation method, and then modified with polydopamine (PDA) through self-polymerization of dopamine, leading to the formation of PDA@DOX/PLGA nanoparticles. Mn(2+) ions were then coordinated on the surfaces of PDA@DOX/PLGA to obtain Mn(2+)-PDA@DOX/PLGA nanoparticles. In our system, Mn(2+)-PDA@DOX/PLGA nanoparticles could destroy tumors in a mouse model directly, by thermal energy deposition, and could also simulate the chemotherapy by thermal-responsive delivery of DOX to enhance tumor therapy. Furthermore, the coordination of Mn(2+) could afford the high magnetic resonance (MR) imaging capability with sensitivity to temperature and pH. The results demonstrated that Mn(2+)-PDA@ DOX/PLGA nanoparticles had a great potential as a smart theranostic agent due to their imaging and tumor-growth-inhibition properties.
Xi, Juqun; Da, Lanyue; Yang, Changshui; Chen, Rui; Gao, Lizeng; Fan, Lei; Han, Jie
Nanoparticle drug delivery carriers, which can implement high performances of multi-functions, are of great interest, especially for improving cancer therapy. Herein, we reported a new approach to construct Mn2+-coordinated doxorubicin (DOX)-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles as a platform for synergistic chemo-photothermal tumor therapy. DOX-loaded PLGA (DOX/PLGA) nanoparticles were first synthesized through a double emulsion-solvent evaporation method, and then modified with polydopamine (PDA) through self-polymerization of dopamine, leading to the formation of PDA@DOX/PLGA nanoparticles. Mn2+ ions were then coordinated on the surfaces of PDA@DOX/PLGA to obtain Mn2+-PDA@DOX/PLGA nanoparticles. In our system, Mn2+-PDA@DOX/PLGA nanoparticles could destroy tumors in a mouse model directly, by thermal energy deposition, and could also simulate the chemotherapy by thermal-responsive delivery of DOX to enhance tumor therapy. Furthermore, the coordination of Mn2+ could afford the high magnetic resonance (MR) imaging capability with sensitivity to temperature and pH. The results demonstrated that Mn2+-PDA@ DOX/PLGA nanoparticles had a great potential as a smart theranostic agent due to their imaging and tumor-growth-inhibition properties. PMID:28479854
Guimarães, Pedro P G; Oliveira, Michele F; Gomes, Alinne D M; Gontijo, Sávio M L; Cortés, Maria E; Campos, Paula P; Viana, Celso T R; Andrade, Silvia P; Sinisterra, Rubén D
The objective of this study was to evaluate the in vivo anti-inflammatory angiogenesis activity and in vitro cytotoxicity on normal and cancer cell models of a drug delivery system consisting of poly(lactic-co-glycolic acid) nanofibers loaded with daunorubicin (PLGA-DNR) that were fabricated using an electrospinning process. The PLGA-DNR nanofibers were also characterized by thermogravimetric analysis (TGA), differential thermal analysis (DTA) and differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and confocal fluorescence microscopy. In vitro release of DNR from the nanofibers and its corresponding mechanism were also evaluated. Sixty-five percent of the DNR was released in an initial burst over 8h, and by 1224 h, eighty-five percent of the DNR had been released. The Higuchi model yielded the best fit to the DNR release profile over the first 8h, and the corresponding data from 24 to 1224 h could be modeled using zero-order kinetics. The PLGA-DNR nanofibers exhibited a higher cytotoxicity to A431 cells than free DNR but a cytotoxicity similar to free DNR against fibroblast cells. A higher antiangiogenic effect of PLGA nanofibers was observed in the in vivo data when compared to free DNR, and no inflammatory potential was observed for the nanofibers. Copyright © 2015 Elsevier B.V. All rights reserved.
Wang, Hua; Liu, Jun; Tao, Shan; Chai, Guihong; Wang, Jianwei; Hu, Fu-Qiang; Yuan, Hong
Purpose Nanoparticles (NPs) that target bone tissue were developed using poly(lactic-co-glycolic acid) (PLGA) copolymers and tetracycline (TC)-based bone-targeting moieties. These NPs are expected to enable the transport of drugs, such as simvastatin (SIM), for the treatment of osteoporosis. Methods The molecular structures of TC–PLGA were validated by 1H-NMR, and the SIM-loaded NPs were prepared using the solvent emulsification method. The surface properties, cytotoxicity, cellular uptake, cell mineralization, bone targeting potential, and animal pharmacodynamics of the TC–PLGA NPs were evaluated and compared to those of PLGA NPs. Results It was confirmed that the average particle size of the NPs was approximately 220 nm. In phosphate-buffered saline (PBS, pH 7.4), the SIM-loaded NPs exhibited a cumulative release of up to 80% within 72 hours. An in vitro cell evaluation indicated that the NPs had an excellent cellular uptake capacity and showed great biocompatibility with MC3T3-E1 cells, thereby reducing the cytotoxic effects of SIM. The cell mineralization assay showed that the SIM-loaded NPs induced osteogenic differentiation and mineralized nodule formation in MC3T3-E1 cells, thereby achieving the same effect as SIM. Preliminary findings from in vitro and in vivo bone affinity assays indicated that the TC–PLGA NPs may display increased bone-targeting efficiency compared to PLGA NPs lacking a TC moiety. The use of SIM-loaded TC–PLGA NPs in treating osteoporosis was tested through animal pharmacodynamics analyses performed in ovariectomized rats, and the results suggested that the SIM-loaded TC–PLGA NPs can improve the curative effects of SIM on the recovery of bone mineral density compared to either SIM-loaded PLGA NPs or SIM alone. Conclusion Bone-targeting NPs, which were based on the conjugation of TC to PLGA copolymers, have the ability to target bone. These NPs may be developed as a delivery system for hydrophobic drugs, and they are expected to
Desai, Kashappa-Goud H.; Schwendeman, Steven P.
Herein, we describe the detailed development of a simple and effective method to microencapsulate vaccine antigens in poly(lactic-co-glycolic acid) (PLGA) by simple mixing of preformed active self-microencapsulating (SM) PLGA microspheres in a low concentration aqueous antigen solution at modest temperature (10-38 °C). Co-encapsulating protein-sorbing vaccine adjuvants and polymer plasticizers were used to “actively” load the protein in the polymer pores and facilitate polymer self-healing at temperature > hydrated polymer glass transition temperature, respectively. The microsphere formulation parameters and loading conditions to provide optimal active self-healing microencapsulation of vaccine antigen in PLGA was investigated. Active self-healing encapsulation of two vaccine antigens, ovalbumin and tetanus toxoid (TT), in PLGA microspheres was adjusted by preparing blank microspheres containing different vaccine adjuvant (aluminum hydroxide (Al(OH)3) or calcium phosphate). Active loading of vaccine antigen in Al(OH)3-PLGA microspheres was found to: a) increase proportionally with an increasing loading of Al(OH)3 (0.88-3 wt%) and addition of porosigen, b) decrease when the inner Al(OH)3/trehalose phase to 1 mL outer oil phase and size of microspheres was respectively > 0.2 mL and 63 μm, and c) change negligibly by PLGA concentration and initial incubation (loading) temperature. Encapsulation of protein sorbing Al(OH)3 in PLGA microspheres resulted in suppression of self-healing of PLGA pores, which was then overcome by improving polymer chain mobility, which in turn was accomplished by coincorporating hydrophobic plasticizers in PLGA. Active self-healing microencapsulation of manufacturing process-labile TT in PLGA was found to: a) obviate micronization- and organic solvent-induced TT degradation, b) improve antigen loading (1.4-1.8 wt% TT) and encapsulation efficiency (~ 97%), c) provide nearly homogeneous distribution and stabilization of antigen in polymer
Mehrasa, Mohammad; Asadollahi, Mohammad Ali; Ghaedi, Kamran; Salehi, Hossein; Arpanaei, Ayyoob
Aligned poly lactic-co-glycolic acid (PLGA) and PLGA/gelatin nanofibrous scaffolds embedded with mesoporous silica nanoparticles (MSNPs) were fabricated using electrospinning method. The mean diameters of nanofibers were 641±24 nm for the pure PLGA scaffolds vs 418±85 nm and 267±58 nm for the PLGA/10 wt% MSNPs and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively. The contact angle measurement results (102°±6.7 for the pure PLGA scaffold vs 81°±6.8 and 18°±8.7 for the PLGA/10 wt% MSNPs and the PLGA/gelatin/10 wt% MSNPs scaffolds, respectively) revealed enhanced hydrophilicity of scaffolds upon incorporation of gelatin and MSNPs. Besides, embedding the scaffolds with MSNPs resulted in improved tensile mechanical properties. Cultivation of PC12 cells on the scaffolds demonstrated that introduction of MSNPs into PLGA and PLGA/gelatin matrices leads to the improved cell attachment and proliferation as well as long cellular processes. DAPI staining results indicated that cell proliferations on the PLGA/10 wt% MSNPs and the PLGA/gelatin/10 wt% MSNPs scaffolds were strikingly (nearly 2.5 and 3 folds, respectively) higher than that on the aligned pure PLGA scaffolds. These results suggest superior properties of silica nanoparticles-incorporated PLGA/gelatin eletrospun nanofibrous scaffolds for the stem cell culture and tissue engineering applications. Copyright © 2015 Elsevier B.V. All rights reserved.
Amjadi, Issa; Rabiee, Mohammad; Hosseini, Motahare-Sadat
Attempts have been made to prepare nanoparticles based on poly(lactic-co-glycolic acid) (PLGA) and doxorubicin. Biological evaluation and physio-chemical characterizations were performed to elucidate the effects of initial drug loading and polymer composition on nanoparticle properties and its antitumor activity. PLGA nanoparticles were formulated by sonication method. Lactide/glycolide ratio and doxorubicin amounts have been tailored. Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were employed to identify the presence of doxorubicin within nanospheres. The in vitro release studies were performed to determine the initial ant net release rates over 24 h and 20 days, respectively. Furthermore, cytotoxicity assay was measured to evaluate therapeutic potency of doxorubicin-loaded nanoparticles. Spectroscopy and thermal results showed that doxorubicin was loaded into the particles successfully. It was observed that lactide/glycolide content of PLGA nanoparticles containing doxorubicin has more prominent role in tuning particle characteristics. Doxorubicin release profiles from PLGA 75 nanospheres demonstrated that the cumulative release rate increased slightly and higher initial burst was detected in comparison to PLGA 50 nanoparticles. MTT data revealed doxorubicin induced antitumor activity was enhanced by encapsulation process, and increasing drug loading and glycolide portion. The results led to the conclusion that by controlling the drug loading and the polymer hydrophilicity, we can adjust the drug targeting and blood clearance, which may play a more prominent role for application in chemotherapy. PMID:24523742
Zhao, Xingyu; Han, Yu; Li, Jiawei; Cai, Bo; Gao, Hang; Feng, Wei; Li, Shuqiang; Liu, Jianguo; Li, Dongsong
Combining biomaterials scaffolds with bone morphogenetic protein-2 (BMP-2) is currently used to promote the regeneration of bone tissue. However, the traditional strategies used to add BMP-2 into the polymer scaffolds directly suffer from limitations that can result in lower growth factor loading and damage the bioactivity of growth factors. In this study, we report the fabrication of poly(lactide-co-glycolide)/hydroxyapatite (PLGA/HA) composite fibrous scaffolds via melt-spinning method to mimic native extracellular matrix (ECM). In order to effectively immobilize BMP-2 on PLGA/HA composite fibrous scaffolds, the surface of the scaffold was modified with polydopamine (PDA) (PDA-PLGA/HA). PDA was chosen as an adhesive polymeric bridge-layer between PLGA/HA fibrous scaffolds and BMP-2. Analysis of the scaffold using scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscope revealed that the PDA coating was attached to the scaffold surface. Moreover, analysis of the scaffold using water contact angle demonstrated an increased hydrophilicity via PDA modification. Furthermore, the PDA coating effectively immobilized BMP-2 on the PDA-PLGA/HA fibrous scaffold and a sustained release profile of BMP-2 was achieved in the BMP-2-immobilized PLGA/HA fibrous scaffold. In vitro experiments showed that BMP-2-immobilized PLGA/HA fibrous scaffold significantly promoted the attachment and proliferation of MC3T3-E1 cells. More importantly, the ALP activity, mRNA expression of osteosis-related genes and calcium deposition in MC3T3-E1 cells cultured on BMP-2-immobilized PLGA/HA fibrous scaffold were significantly increased. These results collectively demonstrate that the BMP-2-immobilized PLGA/HA fibrous scaffold is a promising candidate for bone regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.
He, Huacheng; Markoutsa, Eleni; Zhan, Yihong; Zhang, Jiajia; Xu, Peisheng
Most photothermal converting systems are not biodegradable, which bring the uneasiness when they are administered into human body due to the uncertainty of their fate. Hereby, we developed a mussel-inspired PLGA/polydopamine core-shell nanoparticle for cancer photothermal and chemotherapy. With the help of an anti-EGFR antibody, the nanoparticle could effectively enter head and neck cancer cells and convert near-infrared light to heat to trigger drug release from PLGA core for chemotherapy as well as ablate tumors by the elevated temperature. Due to the unique nanoparticle concentration dependent peak working-temperature nature, an overheating or overburn situation can be easily prevented. Since the nanoparticle was retained in the tumor tissue and subsequently released its payload inside the cancer cells, no any doxorubicin-associated side effects were detected. Thus, the developed mussel-inspired PLGA/polydopamine core-shell nanoparticle could be a safe and effective tool for the treatment of head and neck cancer. The described EGFR targeted PLGA/polydopamine core-shell nanoparticle (PLGA/PD NP) is novel in the following aspects: Different from most photothermal converting nanomaterials, PLGA/PD NP is biodegradable, which eliminates the long-term safety concerns thwarting the clinical application of photothermal therapy. Different from most photothermal nanomaterials, upon NIR irradiation, PLGA/PD NP quickly heats its surrounding environment to a NP concentration dependent peak working temperature and uniquely keeps that temperature constant through the duration of light irradiation. Due to this unique property an overheating or overburn situation for the adjacent healthy tissue can be easily avoided. The PLGA/PD NP releases its payload through detaching PD shell under NIR laser irradiation. The EGFR-targeted doxorubicin-loaded PLGA/PD NP effectively eradicate head and neck tumor in vivo through the synergism of photothermal therapy and chemotherapy while not
Wang, Xiaojie; Shi, Lei; Tu, Qingfeng; Wang, Hongwei; Zhang, Haiyan; Wang, Peiru; Zhang, Linglin; Huang, Zheng; Wang, Xiuli; Zhao, Feng; Luan, Hansen
Background: Squamous cell carcinoma (SCC) is a common skin cancer and its treatment is still difficult. The aim of this study was to evaluate the effectiveness of nanoparticle (NP)-assisted ALA delivery for topical photodynamic therapy (PDT) of cutaneous SCC. Methods: UV-induced cutaneous SCCs were established in hairless mice. ALA loaded polylactic-co-glycolic acid (PLGA) NPs were prepared and characterized. The kinetics of ALA PLGA NPs-induced protoporphyrin IX (PpIX) fluorescence in SCCs, therapeutic efficacy of ALA NP-mediated PDT, and immune responses were examined. Results: PLGA NPs could enhance PpIX production in SCC. ALA PLGA NP mediated topical PDT was more effective than free ALA of the same concentration in treating cutaneous SCC. Conclusion: PLGA NPs provide a promising strategy for delivering ALA in topical PDT of cutaneous SCC.
Feng, Liang; Ward, Jonette A; Li, S Kevin; Tolia, Gaurav; Hao, Jinsong; Choo, Daniel I
Temperature sensitive copolymer systems were previously studied using modified diffusion cells in vitro for intratympanic injection, and the PLGA-PEG-PLGA copolymer systems were found to provide sustained drug delivery for several days. The objectives of the present study were to assess the safety of PLGA-PEG-PLGA copolymers in intratympanic injection in guinea pigs in vivo and to determine the effects of additives glycerol and poloxamer in PLGA-PEGPLGA upon drug release in the diffusion cells in vitro for sustained inner ear drug delivery. In the experiments, the safety of PLGA-PEG-PLGA copolymers to inner ear was evaluated using auditory brainstem response (ABR). The effects of the additives upon drug release from PLGA-PEG-PLGA hydrogel were investigated in the modified Franz diffusion cells in vitro with cidofovir as the model drug. The phase transition temperatures of the PLGA-PEG-PLGA copolymers in the presence of the additives were also determined. In the ABR safety study, the PLGA-PEG-PLGA copolymer alone did not affect hearing when delivered at 0.05-mL dose but caused hearing loss after 0.1-mL injection. In the drug release study, the incorporation of the bioadhesive additive, poloxamer, in the PLGA-PEG-PLGA formulations was found to decrease the rate of drug release whereas the increase in the concentration of the humectant additive, glycerol, provided the opposite effect. In summary, the PLGA-PEG-PLGA copolymer did not show toxicity to the inner ear at the 0.05-mL dose and could provide sustained release that could be controlled by using the additives for inner ear applications.
Baskaran, Mrudhula; Baskaran, Padmamalini; Arulsamy, Navamoney; Thyagarajan, Baskaran
Drugs used in the treatment of diseases can cause several unwanted systemic side effects. A site-specific drug delivery system can eliminate such consequences by delivering drugs to certain target areas of the body where therapeutic effects are required. Here we present the preparation and evaluation of magnetic nanoparticles of capsaicin, the active ingredient in chili peppers, coated with poly-L-lactide co-glycolide (PLGA), a FDA-approved biodegradable bioavailable polymer. PCMN were prepared by solvent-evaporation/coprecipitation technique and their physicochemical and pharmacological characteristics evaluated in vitro. Further, effective pain/inflammation therapeutics of PCMN in a mouse model of inflammation was also studied. We also prepared and evaluated the subcellular localization of PLGA coated fluorescence magnetic nanoparticle (PFMN) in vitro in HEK293 cells. Transmission electron microscopic images of PCMN showed that the size of the nanoparticles were of the order of 10-20 nm. PCMN showed approximately 9.29% drug loading and 89.15% encapsulation efficiencies. In vitro dissolution studies showed an increased solubility of capsaicin due to the nano-size of the PCMN, while PLGA coating allowed sustained release of capsaicin in vitro. The PCMN also reduced paw edema after injection in mice, and confocal microscopy revealed the successful intracellular localization of PLGA-coated fluorescein magnetic nanoparticles in HEK293 cells. The PCMN provided a sustained release of capsaicin in vitro and inhibited carrageenan-induced inflammatory pain in mouse model in vivo. These data suggest that PLGA coating of capsaicin magnetic nanoparticles have the potential to be amenable for a sustained release of capsaicin to relieve pain.
Furtado, Stacia; Abramson, Danielle; Burrill, Roxanne; Olivier, Gloria; Gourd, Celinda; Bubbers, Emily; Mathiowitz, Edith
The bioadhesive polymer, poly(fumaric-co-sebacic) anhydride, p(FASA), was used to fabricate small diameter insulin microspheres and evaluate their in vivo performance in a type 1 diabetic rat as well as a type 1 diabetic dog model. The process of phase inversion nanoencapsulation was used to fabricate p(FASA) microspheres containing insulin. Using laser diffraction spectrometry, 90% of the microspheres used in the fed double dose rat experiments were found to have a volumetric diameter of 5.9 microm or smaller. In comparison, 90% of the microspheres used in fed single dose rat experiments were found to have a volumetric diameter of 2.6 microm or smaller while the microspheres used in the diabetic dog experiments were found to have a volumetric diameter of 1.2 microm or smaller. Insulin microspheres administered to diabetic rats in the fed double dose experiment produced a relative bioavailability (RB) of 23.3% while insulin microspheres administered to diabetic rats in the fed single dose experiment produced a RB of 5.5+/-1.7%. Insulin microspheres administered to fasted diabetic dogs produced a RB of 5.5+/-3.4%.
Kenechukwu, Franklin C.; Momoh, Mumuni A.
Introduction: The aim of this study was to use Eudragit® RL 100 (pH-independent polymer) and magnesium stearate (a hydrophobic droplet stabilizer) in combination to improve the controlled release effect of insulin-loaded Eudragit® entrapped microspheres prepared by the emulsification-coacervation technique. Materials and Methods: Mucoadhesive insulin-loaded microspheres containing magnesium stearate and varying proportions of Eudragit® RL 100 were prepared by the emulsification-coacervation technique and evaluated for thermal properties, physicochemical performance, and in vitro dissolution in acidic and subsequently basic media. Results: Stable, spherical, brownish, discrete, free-flowing and mucoadhesive insulin-loaded microspheres with size range of 14.20 ± 0.30-19.80 ± 0.60 μm and loading efficiency of 74.55 ± 1.05-75.90 ± 1.94% were formed. After 3 h, microspheres prepared with insulin: Eudragit® RL 100 ratios of 1:4, 1:6, and 1:8 released 73.40 ± 1.38, 66.20 ± 1.59, and 71.30 ± 1.27 (%) of insulin, respectively. Conclusion: The physicochemical and physico-technical properties of the microspheres developed in this study demonstrated the effectiveness of the Eudragit® RL entrapped mucoadhesive microspheres (prepared by the emulsification-coacervation technique using varying polymer concentration) as a carrier system for oral insulin delivery. PMID:27051626
Giovino, Concetta; Ayensu, Isaac; Tetteh, John; Boateng, Joshua S
Mucoadhesive chitosan based films, incorporated with insulin loaded nanoparticles (NPs) made of poly(ethylene glycol)methyl ether-block-polylactide (PEG-b-PLA) have been developed and characterised. Blank-NPs were prepared by double emulsion solvent evaporation technique with varying concentrations of the copolymer (5 and 10%, w/v). The optimised formulation was loaded with insulin (model protein) at initial loadings of 2, 5 and 10% with respect to copolymer weight. The developed NPs were analysed for size, size distribution, surface charge, morphology, encapsulation efficiency and drug release. NPs showing negative (ζ)-potential (<-6 mV) with average diameter> 300 nm and a polydispersity index (P.I.) of ≈ 0.2, irrespective of formulation process, were achieved. Insulin encapsulation efficiencies of 70% and 30% for NPs-Insulin-2 and NPs-Insulin-5 were obtained, respectively. The in vitro release behaviour of both formulations showed a classic biphasic sustained release of protein over 5 weeks which was influenced by pH of the release medium. Optimised chitosan films embedded with 3mg of insulin loaded NPs were produced by solvent casting with homogeneous distribution of NPs in the mucoadhesive matrix, which displayed excellent physico-mechanical properties. The drug delivery system has been designed as a novel platform for potential buccal delivery of macromolecules. Copyright © 2012 Elsevier B.V. All rights reserved.
Ahmadi, F.; Derakhshandeh, K.; Jalalizadeh, A.; Mostafaie, A.; Hosseinzadeh, L.
Ovarian cancer is the fifth leading cause of the cancer-related death among women. 9-nitrocamptothecin (9-NC) is a water-insoluble derivative of camptothecin used for the treatment of patients with advanced ovarian cancer. Previous studies showed that the encapsulation of 9-NC in poly (lactic-co-glycolic acid, PLGA) nanoparticles increased the cytotoxic effect of the drug on different cancer cell lines. In the present study, the cytotoxic effects of 9-NC, 9-NC-loaded PLGA and PLGA-polyethylene glycol (PLGA-PEG) nanoparticles with varying degree of PEG (5, 10, and 15%) were evaluated on human ovarian carcinoma cell line. Furthermore, the mode of cell death induced by 9-NC and the optimized 9-NC-loaded PLGA-PEG nanoparticles on A2780 cell line were investigated. 9-NC incorporating nanoparticles were prepared by nanopercipitation method and their physicochemical characteristics were evaluated using standard methods. The results showed that activation of caspase-3 and -9 significantly increased by free 9-NC and PLGA-PEG loaded nanoparticles in A2780 cells. In contrast to the free drug which increased the activation of caspase-8, 9-NC-loaded PLGA-PEG nanoparticles did not alter the activation of caspase-8. Collectively, it appears that apoptosis induced by 9-NC incorporated in PLGA-PEG 5% occurred through the activation of caspase-9 rather than activation of caspase-8 which is the mediator of extrinsic pathway. Moreover, our results confirmed that 9-NC in nanoparticles at the level of gene expression potentiated down-regulation of Bcl-2, up regulation of Bax, and Smac/DIABLO leading to a decrease in mitochondrial membrane potential. Taken together, our results showed that 9-NC incorporated in PLGA-PEG 5% nanoparticles is able to induce apoptosis in A2780 human ovarian carcinoma cells and has the potential for the treatment of ovarian carcinoma. PMID:26487893
Shi, Gang; Ding, Yuanyuan; Zhang, Xin; Wu, Luyan; He, Fei; Ni, Caihua
Hydrophobically modified sodium alginate, poly (lactic-glycolic acid) grafting from sodium alginate (ALG-g-PLGA), was successfully synthesized through direct one-step polymerization of sodium alginate, glycolic acid, and lactic acid. ALG-g-PLGA self-assembled to colloidal nanoparticles and subsequently hydrogel microspheres were obtained by crosslinking ALG-g-PLGA nanoparticles in the solution of calcium chloride. The modified hydrogel microspheres could be used as the drug delivery vehicles for a hydrophobic ibuprofen. Compared with sodium alginate, ALG-g-PLGA demonstrated an improved drug loading rate, encapsulation efficiency, and prolonged release speed. The products, as novel and highly promising biomaterials, have potential applications.
Lark, D S; Fisher-Wellman, K H; Neufer, P D
Skeletal muscle from sedentary obese patients is characterized by depressed electron transport activity, reduced expression of genes required for oxidative metabolism, altered mitochondrial morphology and lower overall mitochondrial content. These findings imply that obesity, or more likely the metabolic imbalance that causes obesity, leads to a progressive decline in mitochondrial function, eventually culminating in mitochondrial dissolution or mitoptosis. A decrease in the sensitivity of skeletal muscle to insulin represents one of the earliest maladies associated with high dietary fat intake and weight gain. Considerable evidence has accumulated to suggest that the cytosolic ectopic accumulation of fatty acid metabolites, including diacylglycerol and ceramides, underlies the development of insulin resistance in skeletal muscle. However, an alternative mechanism has recently been evolving, which places the etiology of insulin resistance in the context of cellular/mitochondrial bioenergetics and redox systems biology. Overnutrition, particularly from high-fat diets, generates fuel overload within the mitochondria, resulting in the accumulation of partially oxidized acylcarnitines, increased mitochondrial hydrogen peroxide (H2O2) emission and a shift to a more oxidized intracellular redox environment. Blocking H2O2 emission prevents the shift in redox environment and preserves insulin sensitivity, providing evidence that the mitochondrial respiratory system is able to sense and respond to cellular metabolic imbalance. Mitochondrial H2O2 emission is a major regulator of protein redox state, as well as the overall cellular redox environment, raising the intriguing possibility that elevated H2O2 emission from nutrient overload may represent the underlying basis for the development of insulin resistance due to disruption of normal redox control mechanisms regulating protein function, including the insulin signaling and glucose transport processes.
Tang, Yu; Singh, Jagdish
The objective of this study was to develop poly (d,l-lactide-co-glycolide) (PLGA) based injectable phase sensitive in situ gel forming delivery system for controlled delivery of aspirin, and to characterize the effect of drug/polymer interaction on the in vitro release of aspirin and polymer degradation. Aspirin was dissolved into PLGA solution in 1-methyl-2-pyrrolidone. Poly(ethylene glycol)400 was used as plasticizer to reduce initial burst release. The solution formulation was injected into aqueous release medium to form a gel depot. Released samples were withdrawn periodically and assayed for aspirin content by high performance liquid chromatography. The effect of aspirin on the degradation of PLGA matrix was evaluated using Proton Nuclear Magnetic Resonance and Gel Permeation Chromatography. PLGA based in situ gel forming formulations controlled the in vitro release of aspirin for 7 days only. Analysis of PLGA matrix residuals revealed that PLGA in aspirin loaded formulations exhibited a significantly (p<0.05) faster degradation compared to blank formulations. These findings suggest that aspirin causes an unusually faster degradation of PLGA. Such faster degradation of PLGA has not been noticed for any other drugs reported in the literature.
Samadder, Asmita; Das, Sreemanti; Das, Jayeeta; Khuda-Bukhsh, Anisur Rahman
The present study evaluates relative efficacies of insulin and PLGA-loaded-nano-insulin (NIn) in combating arsenic-induced impairment of glucose uptake, insulin resistance and mitochondrial dysfunction in L6 skeletal muscle cells. L6 cells were treated with 0.5 mM sodium arsenite for 30 min and then the cells were further treated with either 100 nM insulin (standardized dose) or either of the two doses, 50 nM and 100 nM of nano-insulin. Various biomarkers like pyruvate-kinase and glucokinase, ATP/ADP ratio, mitochondrial membrane potential, cytosolic release of mitochondrial cytochrome c, cell membrane potential and calcium-ion level were studied and analyzed to ascertain the status of mitochondrial functioning in all experimental and control sets of L6 cells. The size, morphology and zeta potential of formulated NIn were determined by using dynamic light scattering, scanning electronic and atomic-force microscopies. Expression of signalling cascades like GLUT4, IRS1, IRS2, UCP2, PI3, and p38 was critically analyzed. Overall results suggested that both insulin and NIn improved mitochondrial functioning in arsenite-intoxicated L6 cells, NIn showing better effects at a much lower dose (at nearly 10-fold decreased dose) than that produced by insulin. Nano-insulin being non-toxic and effective at a much lesser dose, therefore, has potential for therapeutic use in the management of arsenic induced diabetes.
Wang, Xiaojie; Shi, Lei; Huang, Zheng; Wang, Xiuli
Background: Squamous cell carcinoma (SCC) is a common skin cancer and its treatment is still a challenge. Although topical photodynamic therapy (PDT) is effective for treating in situ and superficial SCC, the effectiveness of topical ALA delivery to thick SCC can be limited by its bioavailability. Polylactic-co-glycolic acid nanopartieles (PLGA NPs) might provide a promising ALA delivery strategy. The aim of this study was to evaluate the efficacy of ALA PLGA NPs PDT for the treatment of cutaneous SCC in a mouse model. Methods: ALA loaded PLGA NPs were prepared and characterized. The therapeutic efficacy of ALA PLGA NP mediated PDT in treating UV-induced cutaneous SCC in the mice model were examined. Results: In vivo study showed that ALA PLGA NPs PDT were more effective than free ALA of the same concentration in treating mouse cutaneous SCC. Conclusion: ALA PLGA NPs provides a promising strategy for delivering ALA and treating cutaneous SCC.
Khanal, Shalil; Adhikari, Udhab; Rijal, Nava P.; Bhattarai, Shanta R.; Sankar, Jagannathan; Bhattarai, Narayan
Poly(lactic-co-glycolic acid) (PLGA) based nanoparticles have gained increasing attention in delivery applications due to their capability for controlled drug release characteristics, biocompatibility, and tunable mechanical, as well as degradation, properties. However, thorough study is always required while evaluating potential toxicity of the particles from dose dumping, inconsistent release and drug-polymer interactions. In this research, we developed PLGA nanoparticles modified by chitosan (CS), a cationic and pH responsive polysaccharide that bears repetitive amine groups in its backbone. We used a model drug, diclofenac sodium (DS), a nonsteroidal anti-inflammatory drug (NSAID), to study the drug loading and release characteristics. PLGA nanoparticles were synthesized by double-emulsion solvent evaporation technique. The nanoparticles were evaluated based on their particle size, surface charge, entrapment efficacy, and effect of pH in drug release profile. About 390–420 nm of average diameters and uniform morphology of the particles were confirmed by scanning electron microscope (SEM) imaging and dynamic light scattering (DLS) measurement. Chitosan coating over PLGA surface was confirmed by FTIR and DLS. Drug entrapment efficacy was up to 52%. Chitosan coated PLGA showed a pH responsive drug release in in vitro. The release was about 45% more at pH 5.5 than at pH 7.4. The results of our study indicated the development of chitosan coating over PLGA nanoparticle for pH dependent controlled release DS drug for therapeutic applications. PMID:27490577
Zhang, Jiang; Liu, Yang; Luo, Rifang; Chen, Si; Li, Xin; Yuan, Shuheng; Wang, Jin; Huang, Nan
Drug-eluting stents (DESs) have been an important breakthrough for interventional cardiology applications since 2002. Though successful in reducing restenosis, some adverse clinical problems still emerged, which were mostly caused by the bare-metal stents and non-biodegradable polymer coatings, associated with the delayed endothelialization process. In this study, dexamethasone-loaded poly (lactic-co-glycolic acid) (PLGA) coatings were developed to explore the potential application of dexamethasone-eluting stents. Dexamethasone-eluting PLGA stents were prepared using ultrasonic atomization spray method. For other tests like stability and cytocompatibility and hemocompatibility tests, dexamethasone loaded coatings were deposited on 316L SS wafers. Fourier transform-infrared spectroscopy (FT-IR) results demonstrated that there was no chemical reaction between PLGA and dexamethasone. The balloon expansion experiment and surface morphology observation suggested that the stent coatings were smooth and uniform, and could also withstand the compressive and tensile strains imparted without cracking after stent expansion. The drug release behavior in vitro indicated that dexamethasone existed burst release within 1 day, but it presented linear release characteristics after 6 days. In vitro platelets adhesion, activation test and APTT test were also done, which showed that after blending dexamethasone into PLGA, the hemocompatibility was improved. Besides, dexamethasone and dexamethasone-loaded PLGA coatings could significantly inhibit the attachment and proliferation of smooth muscle cells.
Salama, Hamed A; Ghorab, Mahmoud; Mahmoud, Azza A; Abdel Hady, Mayssa
Nanoparticles fabricated from the biodegradable and biocompatible polymer, polylactic-co-glycolic acid (PLGA), could be a promising system for targeting ocular drug delivery. The objective of this work was to investigate the possibility of encapsulating brinzolamide in PLGA nanoparticles in order to be applied as a subconjunctival injection that could represent a starting point for developing new therapeutic strategies against increase in ocular pressure. The brinzolamide-loaded PLGA nanoparticles were fabricated using emulsion-diffusion-evaporation method with varying concentrations of Tween 80 or poloxamer 188 (Plx) in aqueous and organic phases. The nanoparticles were characterized in terms of particle size and size distribution, entrapment efficiency and in-vitro drug release pattern as well as DSC and X-ray analysis. Nanoparticles prepared using Tween 80 in the aqueous phase showed higher encapsulation efficiency and smaller particle size-values compared to those prepared using Plx. Furthermore, the addition of Plx 188 or Brij 97 to the organic phase in the formulation containing Tween 80 in the aqueous phase led to an increase in the particle diameter-values of the obtained nanoparticles. The nanoparticles had the capacity to release the brinzolamide in a biphasic release profile. The nanoparticles were spherical in shape and the drug was entraped in the nanoparticles in an amorphous form. Selected nanoparticles, injected subconjunctivally in normotensive Albino rabbits, were able to reduce the IOP for up to 10 days. Nanoparticles loaded with brinzolamide with lower particle size were able to reduce the IOP for longer period compared to those with higher particle size. Histopathological studies for the anterior cross sections of the rabbits' eyes revealed that the tested nanoparticles were compatible with the ocular tissue. The overall results support that PLGA nanoparticles, applied as subconjunctival injection, can be considered as a promising carrier for
Szczypaczewska, M; Nazar, K; Kaciuba-Uscilko, H
To find out to what extent body composition affects glucose tolerance, blood glucose (BG) and insulin (IRI) responses to a 100-g oral glucose tolerance test (OGTT) were compared in 10 male body builders, 11 untrained lean control subjects, and 11 mildly obese men, all of similar age (19-35 years). In comparison with the remaining two groups, the body builders had the lowest percentage of fat, although their lean body mass (LBM) in absolute terms did not differ from that in obese subjects. Both BG and IRI concentrations during the OGTT were the lowest in body builders, medium in controls, and the highest in obese men. The differences in glucose tolerance between the groups were also demonstrated by comparison of the subjects' BG levels during the OGTT with the respective mean BG values obtained in a reference group of 42 healthy nonobese men aged from 20 to 55 years. The data indicate that body builders show better glucose tolerance and improved insulin action in comparison with untrained, nonobese subjects of similar age and body weight. Lean body mass in absolute terms cannot, however, be considered as a sole determinant of the insulin action in the body since in mildly obese subjects glucose tolerance was considerably reduced in spite of the fact that their LBM was similar to that in body builders. Either muscle hypertrophy or reduced adiposity may account for the beneficial effects of body building on glucose metabolism.
Rong, Xianfang; Yang, Sixing; Miao, Huamao; Guo, Tingting; Wang, Zhenyu; Shi, Wanru; Mo, Xiaofen; Yuan, Weien; Jin, Tuo
We explored the neuroprotective effects of erythropoietin (EPO)-loaded dextran microparticle-based Poly(DL-lactide-co-glycolide)/Poly(DL-lactide) (PLGA/PLA) microspheres (EPO-dextran PLGA/PLA microspheres) on retinal ganglion cells (RGCs) in optic nerve crush rats for a prolonged period of time. EPO-dextran PLGA/PLA microspheres were prepared first by a novel solid-in-oil-in-water (S/O/W) technique. Then, the in vitro EPO release profile was assessed. Afterward, the bioactive effect of EPO released from EPO-dextran PLGA/PLA microspheres was explored in vitro on the retinal explants. Lastly, the neuroprotective effects of EPO-dextran PLGA/PLA microspheres on RGCs were evaluated in optic nerve crush rats with TUNEL staining for apoptotic RGCs. The level of glial fibrillary acidic protein (GFAP) expressed in retina was explored by immunohistochemistry staining. Survival RGCs were observed by DiI retrograde labeling using a DiI fluorescent tracer (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate). The results demonstrated that a sustained release of EPO from PLGA/PLA microspheres could last for at least 60 days. EPO released from the microspheres showed as efficaciously neuroregenerative as EPO protein solution on retinal explants (P = 0.2554 for neurite density, P = 0.1004 for neurite length). TUNEL staining revealed that EPO-dextran PLGA/PLA microspheres remarkably reduced RGCs death when compared to the control (untreated) group (P < 0.01 at five days and one week post-crush, P < 0.05 at two weeks post-crush). Increased GFAP expression in retina was reduced greatly in EPO-dextran PLGA/PLA microspheres-administrated rats two weeks post optic nerve crush. DiI retrograde labeling revealed that a single injection of EPO-dextran PLGA/PLA microspheres significantly promoted RGCs survival (P < 0.01 at four and eight weeks post-crush). A single intravitreal injection of EPO-dextran PLGA/PLA microspheres appeared to have a prolonged protective effect on
Wang, Dong-Fang; Rong, Wen-Ting; Lu, Yu; Hou, Jie; Qi, Shan-Shan; Xiao, Qing; Zhang, Jue; You, Jin; Yu, Shu-Qin; Xu, Qian
In this study, we successfully synthesized d-α-tocopheryl polyethylene glycol 2000 succinate (TPGS2k) and prepared TPGS2k-modified poly(lactic-co-glycolic acid) nanoparticles (TPGS2k/PLGA NPs) loaded with 7-ethyl-10-hydroxycamptothecin (SN-38), designated TPGS2k/PLGA/SN-38 NPs. Characterization measurements showed that TPGS2k/PLGA/SN-38 NPs displayed flat and spheroidal particles with diameters of 80-104 nm. SN-38 was encapsulated in TPGS2k emulsified PLGA NPs with the entrapment efficiency and loading rates of SN-38 83.6 and 7.85%, respectively. SN-38 could release constantly from TPGS2k/PLGA/SN-38 NPs in vitro. TPGS2k/PLGA/SN-38 NPs induced significantly higher cytotoxicity on A549 cells and the multidrug resistance (MDR) cell line (A549/DDP cells and A549/Taxol cells) compared with free SN-38. Further studies on the mechanism of the NPs in increasing the death of MDR cells showed that following the SN-38 releasing into cytoplasm the remaining TPGS2k/PLGA NPs could reverse the P-gp mediated MDR via interfering with the structure and function of mitochondria and rather than directly inhibiting the enzymatic activity of P-gp ATPase. Therefore, TPGS2k/PLGA NPs can reduce the generation of ATP and the release of energy for the requisite of P-gp efflux transporters. The results indicated that TPGS2k/PLGA NPs could become the nanopharmaceutical materials with the capability to reversal MDR and improve anticancer effects of some chemotherapy drugs as P-gp substrates.
INTRAVrrAL MICROSCOPIC EVIDENCE THAT POLYLACTIDE -POLYGLYCOLIDE (PLGA) DELAYS NEO-OSTEOGENESIS AND NEO-ANGIOGENESIS IN HEMAUNG BON H. Winet ,, J.O...healing in a BCI loaded with an erodible returns to an acceptable level of function, no further copolymer, PLGA ( polylactide -polyglycolide). To surgery is...also must be biocompatible, to the extent that Key Words: Bio-erodible implants, polylactide -poly- they generate no significant foreign-body reaction
Wang, Chenhui; Yu, Changhui; Liu, Jiaxin; Sun, Fengying; Teng, Lesheng; Li, Youxin
The aim of this study was to prepare PCADK/PLGA-blend microspheres for improving the stability of human immunoglobulin G (IgG). The short half-life of antibodies limit their development as therapeutic agents, thus PLGA microspheres were prepared to sustained release antibodies and prolong their half-life. However, the acidic intra-microsphere environment causes the loss of antibody stability and activity. In this study, the effect of PCADK or PLGA degradation products on IgG was investigated by size exclusion chromatography (SEC-HPLC), circular dichroism (CD), fluorescence spectroscopy and antigenicity detection. The degradation products of PCADK exerted a larger influence on IgG than that of PLGA. Then PCADK/PLGA microspheres were prepared by the emulsionsolvent evaporation method and systematically characterized and 20% PCADK were selected as the optimal proportion. In addition, the release profile of microspheres and the stability of the released IgG were investigated. The stability of the IgG released from the PCADK/PLGA microspheres was better than that of IgG released from the PLGA microspheres. Confocal laser scanning microscopy (CLSM) was used to determine the pH inside the microspheres. The IgG-loaded PCADK/PLGA microspheres have important advantages over the PLGA microspheres in terms of IgG stability and could be a good carrier to deliver antibodies for the treatment of disease.
Chen, Xiufen; Chen, Jianzhong; Li, Bowen; Yang, Xiang; Zeng, Rongjie; Liu, Yajun; Li, Tao; Ho, Rodney J Y; Shao, Jingwei
Poly (d,l-lactide-co-glycolide)-poly (ethylene glycol)-poly (d,l-lactide-co-glycolide) triblock copolymers (PLGA-PEG-PLGA) has been proven to be desirable for anti-cancer drug delivery by intravenous administration. But till now there is no report of developing this micelle as a sustained oral formulation for cancer therapy. 3β-acetoxy-urs-12-en-28-oic acid hexamethylenediamine (US597), a derivative of natural product ursolic acid has been developed as a novel cancer metastasis chemopreventive agent by us. Herein, we developed a new oral dosage formulation of PLGA-PEG-PLGA tri-block micelles loaded with US597 (US597@micelles). US597@micelles was prepared by a double emulsion solvent evaporation method, and characterized in regards to mean diameter (<100nm), drug loading (25.9-28.5%), zeta potential (5.76-10.65mV) and encapsulation efficiency (55.7-74.3%), respectively. In vitro, US597@micelles could ameliorate sustained drug release, inhibit cell proliferation by inducing apoptosis (46.6% of late apoptosis), and influence the integrity of nuclei and mitochondrial on HepG2. Moreover, in vivo pharmacokinetic study by UPLC/MS/MS method demonstrated better absorption, metabolism and elimination characters of US597@micelles as an oral dosage form (Cmax=53±49ng/mL, t1/2=8.716±7.033h) over free US597 (Cmax=14±11ng/mL, t1/2=16.433±8.821h). In conclusion, PLGA-PEG-PLGA micelles as a promising oral drug delivery system are able to improve the bioavailability and efficacy of US597 in cancer therapy.
Pereira de Sousa, Irene; Moser, Thomas; Steiner, Corinna; Fichtl, Barbara; Bernkop-Schnürch, Andreas
It was the aim of this study to combine two strategies - namely the virus-mimicking strategy and the surface PEGylation strategy - in order to generate highly mucus permeating nanocarriers for oral insulin delivery. Chondroitin sulphate was covalently conjugated with poly(ethylene glycol) 5 kDa at different degree of modification and with the functionalized polymers NPs were formulated via complexation with chitosan. NPs were characterized by particle size, zeta potential, surface hydrophilicity and permeation ability in porcine mucus and on excised mucosa. The NPs presented a size between 510 and 670 nm and a zeta potential between -1 and -5 mV when dispersed in simulated intestinal fluid. The mucus permeation test revealed a correlation between the NPs hydrophilicity and their ability to move through mucus. A 5-fold higher amount of NPs with the higher degree of PEGylation could permeate through fresh mucus compared to non-PEGylated NPs. Moreover, highly PEGylated NPs showed a 3.7-fold greater ability to be retained in intestinal mucosa against buffer flow compared to unmodified NPs. Finally, insulin was incorporated with a payload of 2.18% and the release profile showed a 65% release within 4h. Results of this study provide strong evidence for the potential of combining different surface modification strategies in order to improve the mucus permeating properties of NPs for oral peptide delivery. Copyright © 2016 Elsevier B.V. All rights reserved.
Park, Wooram; Kim, Dongin; Kang, Han Chang; Bae, You Han; Na, Kun
For long-term, sustained protein delivery, a new, star-shaped block copolymer composed of methoxy poly(ethylene glycol) (mPEG), branched oligoethylenimine (bOEI), and poly(l-histidine) (pHis) was synthesized via the multi-initiation and ring-opening polymerization (ROP) of His N-carboxy anhydride (NCA) on bOEI with a PEG conjugation. The resulting mPEG-bOEI-pHis (POH) had strong buffering capacity within the neutral-to-acidic pH range and was complexed with insulin (Ins) via an electrostatic attraction plus hydrophobic interactions, resulting in the formation of a dual-interaction complex (DIC, weight ratio 2) of approximately 30-60 nm in size. This DIC tolerated high salt concentrations without destabilization, supporting the existence of hydrophobic interactions, and protected Ins from the organic solvent/water interface. The DIC in poly(lactide-co-glycolide) microspheres (PLGA MS) as a long-term Ins delivery formulation was evenly distributed via a double-emulsion method. The DIC-loaded PLGA MS offered a higher Ins loading and a lower initial burst than Ins-loaded PLGA MS. This formulation possessed near zero-order release kinetics (for at least one month). In streptozotocin (STZ)-induced diabetic rats, a DIC-loaded PLGA MS formulation was able to maintain blood-glucose levels at 200-350 mg/dL for the first two weeks and even lower levels (100-200 mg/dL) for the next two weeks. Thus, a new POH polymer and its complex with a drug protein could have potential biological application as a long-term, sustained protein delivery system.
Gidwani, Bina; Vyas, Amber
PLGA nanospheres are considered to be promising drug carrier in the treatment of cancer. Inclusion complex of bendamustine (BM) with epichlorohydrin beta cyclodextrin polymer was prepared by freeze-drying method. Phase solubility study revealed formation of AL type complex with stability constant (Ks = 645 M(-1)). This inclusion complex was encapsulated into PLGA nanospheres using solid-in-oil-in-water (S/O/W) technique. The particle size and zeta potential of PLGA nanospheres loaded with cyclodextrin-complexed BM were about 151.4 ± 2.53 nm and - 31.9 ± (-3.08) mV. In-vitro release study represented biphasic release pattern with 20% burst effect and sustained slow release. DSC studies indicated that inclusion complex incorporated in PLGA nanospheres was not in a crystalline state but existed in an amorphous or molecular state. The cytotoxicity experiment was studied in Z-138 cells and IC50 value was found to be 4.3 ± 0.11 µM. Cell viability studies revealed that the PLGA nanospheres loaded with complex exerts a more pronounced effect on the cancer cells as compared to the free drug. In conclusion, PLGA nanospheres loaded with inclusion complex of BM led to sustained drug delivery. The nanospheres were stable after 3 months of storage conditions with slight change in their particle size, zeta potential and entrapment efficiency.
Andreani, Tatiana; Miziara, Leonardo; Lorenzón, Esteban N; de Souza, Ana Luiza R; Kiill, Charlene P; Fangueiro, Joana F; Garcia, Maria L; Gremião, Palmira D; Silva, Amélia M; Souto, Eliana B
The present paper focuses on the development and characterization of silica nanoparticles (SiNP) coated with hydrophilic polymers as mucoadhesive carriers for oral administration of insulin. SiNP were prepared by sol-gel technology under mild conditions and coated with different hydrophilic polymers, namely, chitosan, sodium alginate or poly(ethylene glycol) (PEG) with low and high molecular weight (PEG 6000 and PEG 20000) to increase the residence time at intestinal mucosa. The mean size and size distribution, association efficiency, insulin structure and insulin thermal denaturation have been determined. The mean nanoparticle diameter ranged from 289 nm to 625 nm with a PI between 0.251 and 0.580. The insulin association efficiency in SiNP was recorded above 70%. After coating, the association efficiency of insulin increased up to 90%, showing the high affinity of the protein to the hydrophilic polymer chains. Circular dichroism (CD) indicated that no conformation changes of insulin structure occurred after loading the peptide into SiNP. Nano-differential scanning calorimetry (nDSC) showed that SiNP shifted the insulin endothermic peak to higher temperatures. The influence of coating on the interaction of nanoparticles with dipalmitoylphosphatidylcholine (DPPC) biomembrane models was also evaluated by nDSC. The increase of ΔH values suggested a strong association of non-coated SiNP and those PEGylated nanoparticles coated with DPPC polar heads by forming hydrogen bonds and/or by electrostatic interaction. The mucoadhesive properties of nanoparticles were examined by studying the interaction with mucin in aqueous solution. SiNP coated with alginate or chitosan showed high contact with mucin. On the other hand, non-coated SiNP and PEGylated SiNP showed lower interaction with mucin, indicating that these nanoparticles can interdiffuse across mucus network. The results of the present work provide valuable data in assessing the in vitro performance of insulin-loaded
Utzinger, Maximilian; Jarzebinska, Anita; Haag, Nicolas; Schweizer, Martin; Winter, Gerhard; Dohmen, Christian; Rudolph, Carsten; Plank, Christian
In this study lipoplexes containing chemically modified messenger RNA (cmRNA) were incorporated into poly (lactic-co-glycolic acid) (PLGA) microspheres via water-in-oil-in-water (W/O/W) double emulsion solvent evaporation technique. The nanoparticle encapsulation by microparticle formation was optimized to achieve lipoplex release and maximum transfection efficiency in surrounding cells. It was possible to adjust characteristic features in surface topology and size of the PLGA-microspheres by varying the extent of lipoplex loading into the polymer matrix. The partial release of lipids and mRNA out of the microparticle system, their accumulation in cells and the production of encoded protein were visualized via fluorescence microscopy. These bioactive microspheres, containing cmRNA bearing lipoplexes, were developed for the incorporation of a therapeutic component into injectable calcium phosphate cements (CPC). Due to the incorporation of PLGA/lipoplex microspheres as a degradable entity, the porosity of the cement phase could additionally be adjusted. This approach of complex nanoparticle incorporation into polymer/cement composites represents a promising example for combining transcript therapy with biomechanical engineering.
Zhang, Shaozhi; Liu, Jiwei; Ge, Baojian; Du, Meiling; Fu, Li; Fu, Yushan; Yan, Qiu
The objective of this study is to investigate the encapsulation of 20(R)-ginsenoside Rg3 (20(R)-Rg3) using polylactic-co-glycolic acid (PLGA) and promotion for its antitumor activity. Preparation and evaluation of the antitumor efficacy of 20(R)-Rg3-loaded PLGA nanoparticles were the first reported. The data will be helpful to apply 20(R)-Rg3 efficiently and broadly in new drug form development and clinical cancer treatment. The nanoparticles were prepared using emulsion and solvent evaporation methods. The uniform particle size and good dispersion were further confirmed by scanning electron microscopy. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was applied to detect cell proliferation after 20(R)-Rg3-loaded PLGA nanoparticles treatment. Western blotting and immunofluorescent staining were used for observation of key proteins related with proliferation and apoptosis. Cell cycle and apoptosis were analyzed by flow cytometer technology. The results showed that the size of 20(R)-Rg3-loaded PLGA was 97.5 nm in diameter, and zeta potential was -28 mV detected by Malvern particle size analyzer. The encapsulation efficiency was 97.5%, and drug loading was 70.2% measured by high-performance liquid chromatography. The in vitro study showed that the encapsulated 20(R)-Rg3 was consecutively released and the release ratio reached to the highest value (19.36%) at the time point of 96 h. The encapsulated 20(R)-Rg3 significantly inhibited the proliferation and induced apoptosis in A431 cancer cells compared with the unencapsulated 20(R)-Rg3, control and PLGA alone. 20(R)-Rg3-loaded PLGA nanoparticles was well prepared and characterized. The antitumor activity was increased after PLGA encapsulation. The data will be beneficial to the development of new dosage forms of 20(R)-Rg3 and extensive application.
Liu, Peifeng; Yu, Hui; Sun, Ying; Zhu, Mingjie; Duan, Yourong
A amphiphilic block copolymer composed of conventional monomethoxy (polyethylene glycol)-poly (d,l-lactide-co-glycolide)-poly (l-lysine) (mPEG-PLGA-b-PLL) was synthesized. The chemical structure of this copolymer and its precursors was confirmed by Fourier Transform Infrared Spectroscopy (FTIR), (1)H Nuclear Magnetic Resonance ((1)H NMR) and Gel Permeation Chromatography (GPC). The copolymer was used to prepare nanoparticles (NPs) that were then loaded with either the anti-cancer drug adriamycin or small interfering RNA-negative (siRNA) using a double emulsion method. MTT assays used to study the in vitro cytotoxicity of mPEG-PLGA-b-PLL NPs showed that these particles were not toxic in huh-7 hepatic carcinoma cells. Confocal laser scanning microscopy (CLSM) and flow cytometer analysis results demonstrated efficient mPEG-PLGA-b-PLL NPs-mediated delivery of both adriamycin and siRNA into the cells. In vivo the targeting delivery of adriamycin or siRNA mediated by mPEG-PLGA-b-PLL NPs in the huh-7 hepatic carcinoma-bearing mice was evaluated using a fluorescence imaging system. The targeting delivery results and froze section analysis confirmed that drug or siRNA is deliver to tumor more efficiently by mPEG-PLGA-b-PLL NPs than free drug or Lipofectamine™2000. The high efficiency delivery of mPEG-PLGA-b-PLL NPs mainly due to the enhancement of cellular uptake. These results imply that mPEG-PLGA-b-PLL NPs have a great potential to be used as an effective carriers for adriamycin or siRNA. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.
Socha, M; Sapin, A; Damgé, C; Maincent, P
Nanoparticles loaded with two different commercial insulins (Actrapid, Novorapid and based on different blends of a biodegradable polyester (poly-epsilon-caprolactone) and a polycationic non-biodegradable acrylic polymer (Eudragit RS) were characterized in vitro. The zeta potential was positive whenever Eudragit RS was part of the nanoparticles matrix. The encapsulation efficiency was ~ 96% except for Novorapid-loaded particles of poly-epsilon-caprolactone (only 35%). In vitro release studies revealed a burst release from nanoparticles, which may be of interest for oral delivery. Novorapid-loaded nanoparticles were orally administered to diabetic rats and allowed the glycemia to be decreased when compared with free nanoparticles.
Keijzer, Chantal; Slütter, Bram; van der Zee, Ruurd; Jiskoot, Wim; van Eden, Willem; Broere, Femke
Development of vaccines in autoimmune diseases has received wide attention over the last decade. However, many vaccines showed limited clinical efficacy. To enhance vaccine efficacy in infectious diseases, biocompatible and biodegradable polymeric nanoparticles have gained interest as antigen delivery systems. We investigated in mice whether antigen-encapsulated PLGA (poly-lactic-co-glycolic acid), PLGA-TMC (N-trimethyl chitosan) or TMC-TPP (tri-polyphosphate) nanoparticles can also be used to modulate the immunological outcome after nasal vaccination. These three nanoparticles enhanced the antigen presentation by dendritic cells, as shown by increased in vitro and in vivo CD4+ T-cell proliferation. However, only nasal PLGA nanoparticles were found to induce an immunoregulatory response as shown by enhanced Foxp3 expression in the nasopharynx associated lymphoid tissue and cervical lymph nodes. Nasal administration of OVA-containing PLGA particle resulted in functional suppression of an OVA-specific Th-1 mediated delayed-type hypersensitivity reaction, while TMC-TPP nanoparticles induced humoral immunity, which coincided with the enhanced generation of OVA-specific B-cells in the cervical lymph nodes. Intranasal treatment with Hsp70-mB29a peptide-loaded PLGA nanoparticles suppressed proteoglycan-induced arthritis, leading to a significant reduction of disease. We have uncovered a role for PLGA nanoparticles to enhance CD4+ T-cell mediated immunomodulation after nasal application. The exploitation of this differential regulation of nanoparticles to modulate nasal immune responses can lead to innovative vaccine development for prophylactic or therapeutic vaccination in infectious or autoimmune diseases. PMID:22073184
Keijzer, Chantal; Slütter, Bram; van der Zee, Ruurd; Jiskoot, Wim; van Eden, Willem; Broere, Femke
Development of vaccines in autoimmune diseases has received wide attention over the last decade. However, many vaccines showed limited clinical efficacy. To enhance vaccine efficacy in infectious diseases, biocompatible and biodegradable polymeric nanoparticles have gained interest as antigen delivery systems. We investigated in mice whether antigen-encapsulated PLGA (poly-lactic-co-glycolic acid), PLGA-TMC (N-trimethyl chitosan) or TMC-TPP (tri-polyphosphate) nanoparticles can also be used to modulate the immunological outcome after nasal vaccination. These three nanoparticles enhanced the antigen presentation by dendritic cells, as shown by increased in vitro and in vivo CD4(+) T-cell proliferation. However, only nasal PLGA nanoparticles were found to induce an immunoregulatory response as shown by enhanced Foxp3 expression in the nasopharynx associated lymphoid tissue and cervical lymph nodes. Nasal administration of OVA-containing PLGA particle resulted in functional suppression of an OVA-specific Th-1 mediated delayed-type hypersensitivity reaction, while TMC-TPP nanoparticles induced humoral immunity, which coincided with the enhanced generation of OVA-specific B-cells in the cervical lymph nodes. Intranasal treatment with Hsp70-mB29a peptide-loaded PLGA nanoparticles suppressed proteoglycan-induced arthritis, leading to a significant reduction of disease. We have uncovered a role for PLGA nanoparticles to enhance CD4(+) T-cell mediated immunomodulation after nasal application. The exploitation of this differential regulation of nanoparticles to modulate nasal immune responses can lead to innovative vaccine development for prophylactic or therapeutic vaccination in infectious or autoimmune diseases.
Frasco, Manuela F; Almeida, Gabriela M; Santos-Silva, Filipe; Pereira, Maria do Carmo; Coelho, Manuel A N
The aim of this study was to develop a drug delivery system based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles for an efficient and targeted action of the proteasome inhibitor bortezomib against pancreatic cancer cells. The PLGA nanoparticles were formulated with a poloxamer, and further surface-modified with transferrin for tumor targeting. The nanoparticles were characterized as polymer carriers of bortezomib, and the cellular uptake and growth inhibitory effects were evaluated in pancreatic cells. Cellular internalization of nanoparticles was observed in normal and cancer cells, but with higher uptake by cancer cells. The sustained release of the loaded bortezomib from PLGA nanoparticles showed cytotoxic effects against pancreatic normal and cancer cells. Noteworthy differential cytotoxicity was attained by transferrin surface-modified PLGA nanoparticles since significant cell growth inhibition by delivered bortezomib was only observed in cancer cells. These findings demonstrate that the ligand transferrin enhanced the targeted delivery of bortezomib-loaded PLGA nanoparticles to pancreatic cancer cells. These in vitro results highlight the transferrin surface-modified PLGA nanoparticles as a promising system for targeted delivery of anticancer drugs.
Liu, Zhiqiang; Li, Xia; Xiu, Bingshui; Duan, Cuimi; Li, Jiangxue; Zhang, Xuhui; Yang, Xiqin; Dai, Wenhao; Johnson, Heather; Zhang, Heqiu; Feng, Xiaoyan
Particle size has been demonstrated as a key parameter influencing the phagocytosis of drug-loaded PLGA microspheres (MS) by the target cells. However, the current preparative methods were either insufficient in controlling the homogeneity of the produced MS, or requires sophisticated and costly equipment. This study aimed to explore a simple and economical method for uniform PLGA MS preparation. Based on the heterogeneous emulsification of routine mechanical stirring, we designed an adjuvant strategy to enhance the homogeneity of MS. By using glass beads as adjutant, the dispersion produced during mechanical stirring was much more homogeneous in the solution. The particles produced were much smaller and the size distribution was much narrower as compared with those produced using the routine mechanical stirring method under the same condition. After enrichment by selective centrifugation, about 60% of the particles of similar size were obtained, providing further evidence for the efficiency of the novel method in controlling particle homogeneity. Further, the method was applied to prepare rifampicin-loaded PLGA MS of the optimized size for macrophage uptake. The functional evaluation showed that the prepared PLGA MS could efficiently deliver an antitubercular drug into macrophages and maintain a higher intracellular concentration by controlled release, suggesting the potential application of the method in PLGA MS-based drug delivery. Collectively, the study provided a simple and economical method for preparing uniform-sized PLGA MS with potential of widespread applications.
Domínguez Coello, Santiago; Cabrera de León, Antonio; Rodríguez Pérez, María C; Borges Álamo, Carlos; Carrillo Fernández, Lourdes; Almeida González, Delia; García Yanes, Jezabel; González Hernández, Ana; Brito Díaz, Buenaventura; Aguirre-Jaime, Armando
The involvement of carbohydrates in triggering insulin resistance (IR) remains a source of controversy. To study the relation between glycemic index (GI), glycemic load (GL), and fructose with insulin resistance in a predominantly rural population in the Canary Islands. Cross-sectional study carried out in 668 nondiabetic people aged 18-75. IR was estimated with serum glucose and C-peptide (HOMA2-IR). Nutrient intakes were obtained from a validated food frequency questionnaire. ANOVA was used to analyze nutrient distribution across quartiles of HOMA2-IR. Four multivariate nutrient density models (dependent variable: log-transformed HOMA2-IR) which differed only in the kinds of carbohydrates included were tested (Model 1: carbohydrates; Model 2: GI and then GL; Model 3: free fructose, other simple sugars and starch; Model 4: total fructose, remaining sugars and starch). There was no association between GI and IR. There was a direct association between GL (P < 0.001), fructose (free [P = 0.001], total [P = 0.013]), energy intake (P < 0.001), fruit fiber (<0.001), and glucose (P = 0.003) with IR. There was an inverse association between cereal (P = 0.008) and vegetable fiber (P < 0.001) and IR. Multivariate models corroborated the association of carbohydrates, GL, fructose, vegetable fiber, and energy intake with IR. The association between GL and IR disappeared when Model 2 was adjusted by total fructose intake. There was a direct association between fructose intake and IR. There was no relationship between GI and IR. Although a direct association of GL with IR was detected, it was attributable to the consumption of fructose.
Chereddy, Kiran Kumar; Vandermeulen, Gaëlle; Préat, Véronique
Wound treatment remains one of the most prevalent and economically burdensome healthcare issues in the world. Current treatment options are limited and require repeated administrations which led to the development of new therapeutics to satisfy the unmet clinical needs. Many potent wound healing agents were discovered but most of them are fragile and/or sensitive to in vivo conditions. Poly(lactic-co-glycolic acid) (PLGA) is a widely used biodegradable polymer approved by food and drug administration and European medicines agency as an excipient for parenteral administrations. It is a well-established drug delivery system in various medical applications. The aim of the current review is to elaborate the applications of PLGA based drug delivery systems carrying different wound healing agents and also present PLGA itself as a wound healing promoter. PLGA carriers encapsulating drugs such as antibiotics, anti-inflammatory drugs, proteins/peptides, and nucleic acids targeting various phases/signaling cycles of wound healing, are discussed with examples. The combined therapeutic effects of PLGA and a loaded drug on wound healing are also mentioned. © 2016 by the Wound Healing Society.
Wischke, Christian; Zhang, Ying; Mittal, Sachin; Schwendeman, Steven P
Although efficient in vitro, fenretinide has not been successful clinically for either of the targeted indications-cancer prevention and dry age-related macular degeneration-because of various issues, such as low oral bioavailability. Therefore, controlled release carriers for parenteral delivery of fenretinide were developed. After examining the solubility profile of fenretinide, the drug was encapsulated in poly(lactic-co-glycolic acid) (PLGA) microparticles at 20% drug loading by an s/o/w methodology as well as into in situ-forming PLGA implants. The carrier morphology and drug release kinetics in an elevated polysorbate 80-containing release medium were studied. Preformulation studies revealed increased fenretinide solubility in various PLGA solvents including N-methylpyrrolidone (NMP) and 1:9 v/v methanol:methylene chloride. Co-solvent emulsion methods resulted in low encapsulation efficiency. With a s/o/w method, fenretinide release rates from injectable microparticles were adjusted by the o-phase concentration of end-capped PLGA, the drug particle size, and the particle porosity. In situ implants from non-capped PLGA in NMP exhibited a continuous release of ~70% drug over 1 month. Injectable carriers for fenretinide were successfully prepared, exhibiting excellent drug stability. Based on the in vitro release properties of the different carriers, the preferred injection sites and in vivo release rates will be determined in future preclinical studies.
Gould, Toby W. A.; Birchall, John P.; Mallick, Ali S.; Alliston, Tamara; Lustig, Lawrence R.; Shakesheff, Kevin M.
Objective To develop a porous, biodegradable scaffold for mastoid air cell regeneration. Study Design In vitro development of a temperature-sensitive poly(DL-lactic acid-co-glycolic acid)/poly(ethylene glycol) (PLGA/PEG) scaffold tailored for this application. Methods Human mastoid bone microstructure and porosity was investigated using micro-computed tomography. PLGA/PEG-alginate scaffolds were developed and scaffold porosity was assessed. Human bone marrow mesenchymal stem cells (hBM-MSCs) were cultured on the scaffolds in vitro. Scaffolds were loaded with ciprofloxacin and release of ciprofloxacin over time in vitro was assessed. Results Porosity of human mastoid bone was measured at 83% with an average pore size of 1.3mm. PLGA/PEG-alginate scaffold porosity ranged from 43–78% depending on the alginate bead content. hBM-MSCs proliferate on the scaffolds in vitro, and release of ciprofloxacin from the scaffolds was demonstrated over 7–10 weeks. Conclusion The PLGA/PEG-alginate scaffolds developed in this study demonstrate similar structural features to human mastoid bone, support cell growth and display sustained antibiotic release. These scaffolds may be of potential clinical use in mastoid air cell regeneration. Further in vivo studies to assess the suitability of PLGA/PEG-alginate scaffolds for this application are required. PMID:23670365
Sun, Shaoping; Liang, Na; Gong, Xianfeng; An, Weiwei; Kawashima, Yoshiaki; Cui, Fude; Yan, Pengfei
In this study, we designed and developed a new drug delivery system of multifunctional composite microcapsules for oral administration of insulin. Firstly, in order to enhance the encapsulation efficiency, insulin was complexed with functional sodium deoxycholate to form insulin-sodium deoxycholate complex using hydrophobic ion pairing method. Then the complex was encapsulated into poly(lactide-co-glycolide) (PLGA) nanoparticles by emulsion solvent diffusion method. The PLGA nanoparticles have a mean size of 168 nm and a zeta potential of −29.2 mV. The encapsulation efficiency was increased to 94.2% for the complex. In order to deliver insulin to specific gastrointestinal regions and reduce the burst release of insulin from PLGA nanoparticles, hence enhancing the bioavailability of insulin, enteric targeting multifunctional composite microcapsules were further prepared by encapsulating PLGA nanoparticles into pH-sensitive hydroxypropyl methyl cellulose phthalate (HP55) using organic spray-drying method. A pH-dependent insulin release profile was observed for this drug delivery system in vitro. All these strategies help to enhance the encapsulation efficiency, control the drug release, and protect insulin from degradation. In diabetic fasted rats, administration of the composite microcapsules produced a great enhancement in the relative bioavailability, which illustrated that this formulation was an effective candidate for oral insulin delivery. PMID:28036045
Ma, L M; Zhang, Q; Li, Y Z; Gu, Z W
To investigate the possibility of using poly (epsilon-caprolactone-block-D, L-lactide) (PLCA) as a kind of materials to prepare the microparticles drug carrier. PCLA-MP (microparticle, MP) was prepared by double-emulsification solvent evaporation method. Its morphology was examined by scanning electron microscope. Its size diameter was examined by particle analyser. Insulin (INS), as a model drug, was then encapsulated into PCLA-MP (INS-PCLA-MP). HPLC method was established for determining INS in INS-PCLA-MP. An "antibody-capture" procedure was devised for investigating encapsulation mechanism. The in vitro release behaviour of INS-PCLA-MP was determined in phosphatic buffer solution (pH 7.4). The diabetic rat model was established and blood glucose levels were measured using glucose oxidase (GOD-PAP) method to evaluate the hypoglycaemic effects after subcutaneous administration of INS-PCLA-MP. The pharmacological bioavailability (PBA) of INS-PCLA-MP was calculated from the area above the curve (AAC) in contrast with INS-solution. The mean diameter of INS-PCLA-MP was 1.9 microns, while the encapsulation ratio of INS reached to 76.46%. Only 18.25% encapsulated INS was on the surface of the microparticles, it could be measured by "antibody-capture" experiment. The in vitro release curve of INS-PCLA-MP consists of initial rapid release stage followed by slower exponential stage. In pharmacodynamic studies, after subcutaneous administration of INS-PCLA-MP 12 u.kg-1, the hypoglycaemic effect was significant. The PBA of INS-PCLA-MP was 123.08%. PCLA might become a new drug carrier material in the future.
Soares, Sandra; Fonte, Pedro; Costa, Ana; Andrade, José; Seabra, Vítor; Ferreira, Domingos; Reis, Salette; Sarmento, Bruno
This study aims to monitor the secondary structure behaviour of insulin when it is encapsulated into solid lipid nanoparticles (SLN), under the influence of several critical processing parameters. Insulin was used as a therapeutic protein model. Physicochemical properties of insulin-loaded SLN (Ins-SLN) were assessed, with special focus on the insulin secondary structure after its encapsulation into SLN and after freeze-drying using different cryoprotectants (glucose, fructose and sorbitol). Additionally, a 6-month stability study was performed to evaluate the maintenance of insulin secondary structure over time at different storage conditions (4 °C/60% RH, 25 °C/60% RH, 40 °C/75% RH). Ins-SLN were successfully produced with a mean and narrow particle size around 400 nm, zeta potential around -13 mV, an insulin association efficiency of 84%. Physical-chemical properties of SLN were maintained after freeze-drying. FTIR results showed that encapsulated insulin maintained a native-like structure in a degree of similarity around 92% after production, and 84% after freeze-drying. After 6 months, freeze-dried Ins-SLN without cryoprotectant stored at 40 °C/75% RH presented the same degree of structure preservation and morphology. Results revealed that insulin structure can be significantly protected by SLN matrix itself, without a cryoprotectant agent, even using a non-optimized freeze-drying process, and under the harsher storage conditions. Multivariable experimental settled the process parameters to fit with the desired product quality attributes regarding protein and nanoparticle stability.
Tang, Jie; He, Jinfeng; Yang, Chengli; Mao, Yi; Hu, Tingting; Zhang, Lijing; Cao, Hua; Tong, Ai-ping; Song, Xiangrong; He, Gu; Guo, Gang; Luo, Youfu; Zhang, Xiaoning; Xie, Yongmei; Zheng, Yu
A novel calcium phosphate-pDNA complex-embedded PLGA nanoparticles have been developed for delivering therapy genes. CaPi-MsurvivinT34A-PLGA-NPs (abbreviated as ms-CaPi-PLGA-NPs) containing the MsurvivinT34A plasmid and null-CaPi-PLGA-NPs containing the empty plasmid vector as control were prepared. The nanoparticles had mean size around 130 nm and encapsulation efficiency above 85 %. What is more, the drug loading content and zeta potential of ms-CaPi-PLGA-NPs were 0.734 ± 0.007 % and -3.75 ± 1.2 mV, respectively. ms-CaPi-PLGA-NPs combined with Doxil significantly inhibited the proliferation of 4T1 breast cancer cells with IC50 of 0.2937 ± 0.02 µg/mL, which was significantly lower than those of Doxil and null-CaPi-PLGA-NPs ( p < 0.05). Morphological analysis using Hoechst 33342 and PI staining suggested that a lot of 4T1 cells in combination therapy group of ms-CaPi-PLGA-NPs + Doxil showed typical morphological characteristic of late apoptosis and necrosis. Flow cytometry analysis with PI and the apoptosis marker Annexin V-FITC staining confirmed that apoptosis fraction given by ms-CaPi-PLGA-NPs + Doxil was greater than 80 %. Both ms-CaPi-PLGA-NPs and Doxil resulted in cell cycle arrest implying that their synergistic antitumor effect was probably related to the cell cycle regulation. Then, the antitumor effect of ms-CaPi-PLGA-NPs ( i.t.) + Doxil ( i.v.) in vivo was studied using BALB/c mice inoculated with 4T1 cells. The result showed that ms-CaPi-PLGA-NPs + Doxil suppressed the tumor growth most effectively among all the treatment groups. TUNEL assay together with immunohistochemical study on CD31 and VEGF indicated that the ideal antitumor effect of ms-CaPi-PLGA-NPs + Doxil was ascribed to induction of apoptosis (apoptotic index over 90 %) and inhibition of angiogenesis. Toxicity assessment showed that no significant toxic effects were produced after treatment of ms-CaPi-PLGA-NPs + Doxil. Above all, we may conclude that the calcium phosphate-pDNA complex
Ng, Set Hui; Ooi, Ing Hong
Emulsion solvent evaporation technique is widely used to prepare nanoparticles of many organic polymer drug carriers. The mechanism of nanoparticle generation by this technique involves oil-in-water (O/W) microemulsion formation followed by solvent evaporation. Various microemulsion preparation conditions can affect the encapsulation efficiency of drug in the nanoparticulate carrier. In this study, emulsifying speed, emulsifying temperature, and organic-to-aqueous phase ratio were varied and the resulting encapsulation efficiency of a model drug in Poly(Lactide-co-Glycolide) (PLGA) nanoparticles was determined. The organic phase containing PLGA and a model drug dissolved in chloroform was first dispersed in an aqueous solution containing 0.5 %(w/v) Poly(vinyl alcohol) (PVA), which was then homogenized at high speeds. The resulting O/W microemulsion was subsequently subjected to stirring at room temperature for four hours during which the solvent diffused and evaporated gradually. The fine white suspension was centrifuged and freeze-dried. The model drug loading in the PLGA nanoparticles was determined using UV spectrophotometry. Results showed that the encapsulation efficiency of a model drug, salicylic acid, ranged from 8.5% to 17% depending on the microemulsion preparation conditions. Under the same temperature (15 °C) and homogenization speed (19000 rpm) conditions studied, a relatively high organic-to-aqueous phase ratio (1:5) provided salicylic acid loaded PLGA nanoparticles with significantly higher drug encapsulation efficiency. In addition, under all microemulsion preparation conditions, PLGA nanoparticles obtained after solvent evaporation and freeze drying were spherical and aggregation between the nanoparticles was not observed under a high power microscope. This indicates that PLGA nanoparticles with desirable amount of drug and with anticipated size and shape can be realized by controlling emulsification process conditions.
Liu, Peifeng; Wang, Hongbin; Wang, Qi; Sun, Ying; Shen, Ming; Zhu, Mingjie; Wan, Zhiyong; Duan, Yourong
The main purpose of this study was to evaluate the targeting effect of cyclic arginine-glycine-aspartic peptide (cRGD)-modified monomethoxy (polyethylene glycol)-poly (D, L-lactide-co-glycolide)-poly (L-lysine) nanoparticles (mPEG-PLGA-PLL-cRGD NPs) for gastric cancer SGC-7901 cells. We prepared the 5-Fulorouracil (5Fu)-loaded mPEG-PLGA-PLL-cRGD (5Fu/mPEG-PLGA-PLL-cRGD) NPs that had an average particle size of 180 nm and a zeta potential 2.77 mV. The results of cytotoxicity demonstrated the mPEG-PLGA-PLL-cRGD NPs showed the ignorable cytotoxicity and the 5Fu/mPEG-PLGA-PLL-cRGD NPs could significantly enhance the cytotoxicity of 5Fu. In vitro drug release experiments showed that the release of drug was effectively prolonged and sustained. The results of confocal laser scanning microscope (CLSM) and flow cytometer analysis demonstrated that the fluorescence intensity of the SGC-7901 gastric cancer cells treated with Rb/mPEG-PLGA-PLL-cRGD NPs was significantly higher than that treated with Rb, this suggested that Rb/mPEG-PLGA-PLL-cRGD NPs could effectively be internalized by SGC-7901 gastric cancer cells. In summary, the above experimental results illustrate that mPEG-PLGA-PLL-cRGD NPs have great potential to be used as an effective delivery carriers.
Busari, Zulaikha A; Dauda, Kabiru A; Morenikeji, Olajumoke A; Afolayan, Funmilayo; Oyeyemi, Oyetunde T; Meena, Jairam; Sahu, Debasis; Panda, Amulya K
Curcumin is a polyphenolic pigment isolated from the rhizomes of Curcuma longa (turmeric), a medicinal plant widely used in the ancient Indian and Chinese medicine. The antiplasmodial activity of curcumin is often hampered by its fast metabolism and poor water solubility, thus its incorporation into a delivery system could circumvent this problem. This study aimed to evaluate the in vivo antiplasmodial activity and the toxicity assessment of curcumin incorporated into poly (lactic-co-glycolic) acid (PLGA) nanoparticles. Curcumin was loaded with poly (D,L-lactic-co-glycolic acid) (PLGA) using solvent evaporation from oil-in-water single emulsion method. The nanoparticles were characterized and evaluated in vivo for antimalarial activities using Peter's 4-day suppressive protocol in mice model. Hematological and hepatic toxicity assays were performed on whole blood and plasma, respectively. In vivo anti-parasitic test and toxicity assays for free and encapsulated drug were performed at 5 and 10 mg/kg. In vitro cytotoxicity of free and PLGA encapsulated curcumin (Cur-PLGA) to RAW 264.7 cell line was also determined at varying concentrations (1000-7.8 μg/mL). The size and entrapment efficiency of the nanoparticulate drug formulated was 291.2 ± 82.1 nm and 21.8 ± 0.4 respectively. The percentage parasite suppression (56.8%) at 5 mg/kg was significantly higher than in free drug (40.5%) of similar concentration (p < 0.05) but not at 10 mg/kg (49.5%) at 4-day post-treatment. There were no significant differences in most of the recorded blood parameters in free curcumin and PLGA encapsulated nanoparticulate form (p > 0.05) except in lymphocytes which were significantly higher in Cur-PLGA compared to the free drug (p < 0.05). There were no significant differences in hepatotoxic biomarkers; aspartate aminotransferase and alanine aminotransferase concentrations in various treatment groups (p > 0.05). At higher concentrations (1000 and 500 μg/mL), Cur-PLGA entrapped
Mandiwana, Vusani; Kalombo, Lonji; Venter, Kobus; Sathekge, Mike; Grobler, Anne; Zeevaart, Jan Rijn
Developing nanoparticulate delivery systems that will allow easy movement and localization of a drug to the target tissue and provide more controlled release of the drug in vivo is a challenge in nanomedicine. The aim of this study was to evaluate the biodistribution of poly( d, l-lactide- co-glycolide) (PLGA) nanoparticles containing samarium-153 oxide ([153Sm]Sm2O3) in vivo to prove that orally administered nanoparticles alter the biodistribution of a drug. These were then activated in a nuclear reactor to produce radioactive 153Sm-loaded-PLGA nanoparticles. The nanoparticles were characterized for size, zeta potential, and morphology. The nanoparticles were orally and intravenously (IV) administered to rats in order to trace their uptake through imaging and biodistribution studies. The 153Sm-loaded-PLGA nanoparticles had an average size of 281 ± 6.3 nm and a PDI average of 0.22. The zeta potential ranged between 5 and 20 mV. The [153Sm]Sm2O3 loaded PLGA nanoparticles, orally administered were distributed to most organs at low levels, indicating that there was absorption of nanoparticles. While the IV injected [153Sm]Sm2O3-loaded PLGA nanoparticles exhibited the highest localization of nanoparticles in the spleen (8.63 %ID/g) and liver (3.07 %ID/g), confirming that nanoparticles are rapidly removed from the blood by the RES, leading to rapid uptake in the liver and spleen. From the biodistribution data obtained, it is clear that polymeric nanoscale delivery systems would be suitable for improving permeability and thus the bioavailability of therapeutic compounds.
Ciampelli, M; Fulghesu, A M; Guido, M; Murgia, F; Muzj, G; Belosi, C; Fortini, A; Cento, R; Lanzone, A
In order to evaluate the involvement of endogenous opiates in the insulin disorders of polycystic ovary syndrome (PCOs) a total of 25 PCOs women and 11 normo-ovulatory controls were studied by comparing the effect of a chronic opioid blockade on beta-cells responsiveness to oral glucose load and to intravenous glucagon bolus. Each patient, studied on follicular phase, underwent to oral glucose tolerance test (OGTT), and, 2 days later, to a glucagon intravenous bolus (1 mg); these tests were then repeated after 6 weeks of naltrexone treatment (50 mg orally). Naltrexone treatment did not modify the insulin secretory patterns of control subjects, whereas the same therapy significantly reduced, in hyperinsulinemic PCOs women, the beta-cell hyperresponsiveness both to oral glucose load and to intravenous glucagon (p < 0.05 and p < 0.01, respectively), even if with different mean percent decrease (32% OGTT vs. 45% glucagon, p < 0.05). Moreover, normoinsulinemic PCOs patients showed a slight, but not significantly increase in the beta-cells response to OGTT after opioid blockade, whereas, in the same situation, the insulin release after glucagon bolus was significantly reduced (p < 0.01). Chronic opioid blockade did not modify gonadotropins, steroids and SHBG levels in either group. Our data show that naltrexone treatment is able to reduce the beta-cell response to a direct intravenous secretagogue stimulus in all PCOs patients, while only in hyperinsulinemic PCOs subjects the same treatment is effective in reducing the exaggerated insulin secretion after oral glucose load. The reason for such a discrepancy could be ascribed to a different effect of opioids on first- and second-phase insulin secretion, or, alternatively, to an involvement of other secretagogue factors, such as glucoincretins.
Wang, Hong; Zhang, Guangxing; Ma, Xueqin; Liu, Yanhua; Feng, Jun; Park, Kinam; Wang, Wenping
Poly (lactide-co-glycolide) (PLGA) microparticles are widely used for controlled drug delivery. Emulsion methods have been commonly used for preparation of PLGA microparticles, but they usually result in low loading capacity, especially for drugs with poor solubility in organic solvents. In the present study, the nanocrystal technology and a water-soluble polymer template method were used to fabricate nanocrystal-loaded microparticles with improved drug loading and encapsulation efficiency for prolonged delivery of breviscapine. Breviscapine nanocrystals were prepared using a precipitation-ultrasonication method and further loaded into PLGA microparticles by casting in a mold from a water-soluble polymer. The obtained disc-like particles were then characterized and compared with the spherical particles prepared by an emulsion-solvent evaporation method. X-ray powder diffraction (XRPD) and confocal laser scanning microscopy (CLSM) analysis confirmed a highly-dispersed state of breviscapine inside the microparticles. The drug form, loading percentage and fabrication techniques significantly affected the loading capacity and efficiency of breviscapine in PLGA microparticles, and their release performance as well. Drug loading was increased from 2.4 % up to 15.3 % when both nanocrystal and template methods were applied, and encapsulation efficiency increased from 48.5 % to 91.9 %. But loading efficiency was reduced as the drug loading was increased. All microparticles showed an initial burst release, and then a slow release period of 28 days followed by an erosion-accelerated release phase, which provides a sustained delivery of breviscapine over a month. A relatively stable serum drug level for more than 30 days was observed after intramuscular injection of microparticles in rats. Therefore, PLGA microparticles loaded with nanocrystals of poorly soluble drugs provided a promising approach for long-term therapeutic products characterized with preferable in vitro and in
Sjörs, A; Jansson, P-A; Eriksson, J W; Jonsdottir, I H
Allostatic load (AL) has been shown to be a useful marker of physiological strain during chronic stress and burnout in non-clinical working populations. The usability of the AL index for a clinical population with severe stress-related exhaustion was tested in this study. Thirteen biomarkers assembled as an AL index were analysed using blood samples from 90 patients with stress-related exhaustion (43 men and 47 women, age 31-61 years) and 90 healthy controls (46 men and 44 women, age 25-56 years). The AL scores did not differ between patients and controls. For men, some indication of higher cardiovascular risk was seen in the patient group: male patients had higher body mass index and waist-hip ratio and a poorer blood lipid status than male controls. We found lower plasma glucose concentrations in both female and male patients than those in controls. The male patients also showed increased fasting serum insulin concentrations. Further analysis using homeostasis model assessment for insulin resistance and β-cell function showed indications of insulin resistance in the patient group, particularly in the males, and an increased insulin secretion in both male and female patients. In conclusion, AL index does not seem to capture plausible physiological strain in patients diagnosed with stress-related exhaustion. The finding of lower plasma glucose concentrations, probably due to higher insulin secretion, in patients with severe stress-related exhaustion, needs to be further investigated, including mechanisms and the clinical relevance.
Locatelli, Erica; Comes Franchini, Mauro
During the past decades many synthetic polymers have been studied for nanomedicine applications and in particular as drug delivery systems. For this purpose, polymers must be non-toxic, biodegradable, and biocompatible. Polylactic- co-glycolic acid (PLGA) is one of the most studied polymers due to its complete biodegradability and ability to self-assemble into nanometric micelles that are able to entrap small molecules like drugs and to release them into body in a time-dependent manner. Despite fine qualities, using PLGA polymeric nanoparticles for in vivo applications still remains an open challenge due to many factors such as poor stability in water, big diameter (150-200 nm), and the removal of these nanocarriers from the blood stream by the liver and spleen thus reducing the concentration of drugs drastically in tumor tissue. Polyethylene glycol (PEG) is the most used polymers for drug delivery applications and the first PEGylated product is already on the market for over 20 years. This is due to its stealth behavior that inhibits the fast recognition by the immune system (opsonization) and generally leads to a reduced blood clearance of nanocarriers increasing blood circulation time. Furthermore, PEG is hydrophilic and able to stabilize nanoparticles by steric and not ionic effects especially in water. PLGA-PEG block copolymer is an emergent system because it can be easily synthesized and it possesses all good qualities of PLGA and also PEG capability so in the last decade it arose as one of the most promising systems for nanoparticles formation, drug loading, and in vivo drug delivery applications. This review will discuss briefly on PLGA- b-PEG synthesis and physicochemical properties, together with its improved qualities with respect to the single PLGA and PEG polymers. Moreover, we will focus on but in particular will treat nanoparticles formation and uses as new drug delivery system for nanomedical applications.
Yadav, Awesh K; Agarwal, Abhinav; Rai, Gopal; Mishra, Pradeep; Jain, Sanyog; Mishra, Anil K; Agrawal, Himanshu; Agrawal, Govind P
The present investigation was aimed to develop and explore the prospective of engineered PLGA nanoparticles as vehicles for targeted delivery of 5-fluorouracil (5-FU). Nanoparticles of 5-FU-loaded hyaluronic acid-poly(ethylene glycol)-poly(lactide-co-glycolide) (HA-PEG-PLGA-FU) copolymer were prepared and characterized by FTIR, NMR, transmission electron microscopy, particle size analysis, DSC, and X-ray diffractometer measurement studies. The nanoparticulate formulation was evaluated for in vitro release, hemolytic toxicity, and hematological toxicity. Cytotoxicity studies were performed on Ehrlich ascites tumor (EAT) cell lines using MTT cell proliferation assay. Biodistribution studies of 99m Tc labeled formulation were conducted on EAT-bearing mice. The in vivo tumor inhibition study was also performed after i.v. administration of HA-PEG-PLGA-FU nanoparticles. The HA conjugated formulation was found to be less hemolytic but more cytotoxic as compared to free drug. The hematological data suggested that HA-PEG-PLGA-FU formulation was less immunogenic compared to plain drug. The tissue distribution studies displayed that HA-PEG-PLGA-FU were able to deliver a higher concentration of 5-FU in the tumor mass. In addition, the HA-PEG-PLGA-FU nanoparticles reduced tumor volume significantly in comparison with 5-FU. Thus, it was concluded that the conjugation of HA imparts targetability to the formulation, and enhanced permeation and retention effect ruled out its access to the non-tumor tissues, at the same time favored selective entry in tumors, thereby reducing the side-effects both in vitro and in vivo.
Shah, Ronak B; Schwendeman, Steven P
A biomimetic approach to organic solvent-free microencapsulation of proteins based on the self-healing capacity of poly (DL)-lactic-co-glycolic acid (PLGA) microspheres containing glycosaminoglycan-like biopolymers (BPs), was examined. To screen BPs, aqueous solutions of BP [high molecular weight dextran sulfate (HDS), low molecular weight dextran sulfate (LDS), chondroitin sulfate (CS), heparin (HP), hyaluronic acid (HA), chitosan (CH)] and model protein lysozyme (LYZ) were combined in different molar and mass ratios, at 37 °C and pH7. The BP-PLGA microspheres (20-63 μm) were prepared by a double water-oil-water emulsion method with a range of BP content, and trehalose and MgCO3 to control microclimate pH and to create percolating pores for protein. Biomimetic active self-encapsulation (ASE) of proteins [LYZ, vascular endothelial growth factor165 (VEGF) and fibroblast growth factor (FgF-20)] was accomplished by incubating blank BP-PLGA microspheres in low concentration protein solutions at ~24 °C, for 48 h. Pore closure was induced at 42.5 °C under mild agitation for 42h. Formulation parameters of BP-PLGA microspheres and loading conditions were studied to optimize protein loading and subsequent release. LDS and HP were found to bind >95% LYZ at BP:LYZ>0.125 w/w, whereas HDS and CS bound >80% LYZ at BP:LYZ of 0.25-1 and <0.33, respectively. HA-PLGA microspheres were found to be not ideal for obtaining high protein loading (>2% w/w of LYZ). Sulfated BP-PLGA microspheres were capable of loading LYZ (~2-7% w/w), VEGF (~4% w/w), and FgF-20 (~2% w/w) with high efficiency. Protein loading was found to be dependent on the loading solution concentration, with higher protein loading obtained at higher loading solution concentration within the range investigated. Loading also increased with content of sulfated BP in microspheres. Release kinetics of proteins was evaluated in-vitro with complete release media replacement. Rate and extent of release were found to depend
Shah, Ronak B.; Schwendeman, Steven P.
A biomimetic approach to organic solvent-free microencapsulation of proteins based on the self-healing capacity of poly (DL)-lactic-co-glycolic acid (PLGA) microspheres containing glycosaminoglycan-like biopolymers (BPs), was examined. To screen BPs, aqueous solutions of BP [high molecular weight dextran sulfate (HDS), low molecular weight dextran sulfate (LDS), chondroitin sulfate (CS), heparin (HP), hyaluronic acid (HA), chitosan (CH)] and model protein lysozyme (LYZ) were combined in different molar and mass ratios, at 37 °C and pH 7. The BP-PLGA microspheres (20–63 µm) were prepared by a double water-oil-water emulsion method with a range of BP content, and trehalose and MgCO3 to control microclimate pH and to create percolating pores for protein. Biomimetic active self-encapsulation (ASE) of proteins [LYZ, vascular endothelial growth factor165 (VEGF) and fibroblast growth factor (FgF-20)] was accomplished by incubating blank BP-PLGA microspheres in low concentration protein solutions at ~24 °C, for 48 h. Pore closure was induced at 42.5 °C under mild agitation for 42 h. Formulation parameters of BP-PLGA microspheres and loading conditions were studied to optimize protein loading and subsequent release. LDS and HP were found to bind >95% LYZ at BP:LYZ >0.125 w/w, whereas HDS and CS bound > 80% LYZ at BP:LYZ of 0.25–1 and < 0.33, respectively. HA-PLGA microspheres were found to be not ideal for obtaining high protein loading (>2% w/w of LYZ). Sulfated BP-PLGA microspheres were capable of loading LYZ (~2–7 % w/w), VEGF (~ 4% w/w), and FgF-20 (~2% w/w) with high efficiency. Protein loading was found to be dependent on the loading solution concentration, with higher protein loading obtained at higher loading solution concentration within the range investigated. Loading also increased with content of sulfated BP in microspheres. Release kinetics of proteins was evaluated in-vitro with complete release media replacement. Rate and extent of release were
Rauta, Pradipta Ranjan; Nayak, Bismita
Advanced vaccine research approaches needs to explore on biodegradable nanoparticles (NPs) based vaccine carrier that can serve as antigen delivery systems as well as immuno-stimulatory action to induce both innate and adaptive immune response in fish. Immunogenicity of PLA and PLGA NPs encapsulating outer membrane protein (Omp) antigen of Aeromonas hydrophila were evaluated through intra-peritoneal injection in fish, Labeo rohita. Antigen loaded PLA-Omp (223.5 ± 13.19 nm) and PLGA-Omp (166.4 ± 21.23 nm) NPs were prepared using double emulsion method by efficiently encapsulating the antigen reaching the encapsulation efficiency 44 ± 4.58% and 59.33 ± 5.13% respectively. Our formulated PLA Omp and PLGA-Omp NPs were in nanometer range (<500 nm) and could be successfully endocyted in the body. Despite low antigen loading in PLA-Omp, it showed considerably slower antigen release in vitro than PLGA-Omp NPs. Other physical properties like zetapotential values and poly dispersity index (PDI) confirmed the stability as well as monodisperse nature of the formulated nanoparticles. The spherical and isolated nature of PLA-Omp and PLGA-Omp NPs were revealed by SEM analysis. Upon immunization of all antigenic formulations (PLA-Omp NP, PLGA-Omp NP, FIA-Omp, PLA NP, PLGA NP, PBS as control), significant higher bacterial agglutination titre and haemolytic activity were observed in case of PLA-Omp and PLGA-Omp immunized groups than rest groups at both 21 days and 42 days. The specific antibody response was significantly increased and persisted up to 42 days of post immunization by PLA-Omp, PLGA-Omp, FIA-Omp. PLA-Omp NPs showed better immune response (higher bacterial agglutination titre, haemolytic activity, specific antibody titre, higher percent survival upon A. hydrophila challenge) than PLGA-Omp in L. rohita confirming its better efficacy. Comparable antibody response of PLA-Omp and PLGA-Omp with FIA-Omp treated groups suggested that PLA and PLGA could be replacement for
Halayqa, Mohammed; Domańska, Urszula
In our study, poly(dl-lactide-co-glycolide) (PLGA) nanoparticles loaded with perphenazine (PPH) and chlorpromazine hydrochloride (CPZ-HCl) were formulated by emulsion solvent evaporation technique. The effect of various processing variables, including PLGA concentration, theoretical drug loading, poly(vinyl alcohol) (PVA) concentration and the power of sonication were assessed systematically to obtain higher encapsulation efficiency and to minimize the nanoparticles size. By the optimization formulation process, the nanoparticles were obtained in submicron size from 325.5 ± 32.4 to 374.3 ± 10.1 nm for nanoparticles loaded with PPH and CPZ-HCl, respectively. Nanoparticles observed by scanning electron microscopy (SEM) presented smooth surface and spherical shape. The encapsulation efficiency of nanoparticles loaded with PPH and CPZ-HCl were 83.9% and 71.0%, respectively. The drug loading were 51.1% and 39.4% for PPH and CPZ-HCl, respectively. Lyophilized nanoparticles with different PLGA concentration 0.8%, 1.3% and 1.6% (w/v) in formulation process were evaluated for in vitro release in phosphate buffered saline (pH = 7.4) by using dialysis bags. The release profile for both drugs have shown that the rate of PPH and CPZ-HCl release were dependent on a size and amount of drugs in the nanoparticles.
Halayqa, Mohammed; Domańska, Urszula
In our study, poly(dl-lactide-co-glycolide) (PLGA) nanoparticles loaded with perphenazine (PPH) and chlorpromazine hydrochloride (CPZ-HCl) were formulated by emulsion solvent evaporation technique. The effect of various processing variables, including PLGA concentration, theoretical drug loading, poly(vinyl alcohol) (PVA) concentration and the power of sonication were assessed systematically to obtain higher encapsulation efficiency and to minimize the nanoparticles size. By the optimization formulation process, the nanoparticles were obtained in submicron size from 325.5 ± 32.4 to 374.3 ± 10.1 nm for nanoparticles loaded with PPH and CPZ-HCl, respectively. Nanoparticles observed by scanning electron microscopy (SEM) presented smooth surface and spherical shape. The encapsulation efficiency of nanoparticles loaded with PPH and CPZ-HCl were 83.9% and 71.0%, respectively. The drug loading were 51.1% and 39.4% for PPH and CPZ-HCl, respectively. Lyophilized nanoparticles with different PLGA concentration 0.8%, 1.3% and 1.6% (w/v) in formulation process were evaluated for in vitro release in phosphate buffered saline (pH = 7.4) by using dialysis bags. The release profile for both drugs have shown that the rate of PPH and CPZ-HCl release were dependent on a size and amount of drugs in the nanoparticles. PMID:25535080
Jose, S; Sowmya, S; Cinu, T A; Aleykutty, N A; Thomas, S; Souto, E B
The present paper focuses on the development and in vitro/in vivo characterization of nanoparticles composed of poly-(D,L)-Lactide-co-Glycolide (PLGA) loading Bacoside-A, as a new approach for the brain delivery of the neuroprotective drug for the treatment of neurodegenerative disorders (e.g. Alzheimer Disease). Bacoside-A-loaded PLGA nanoparticles were prepared via o/w emulsion solvent evaporation technique. Surface of the nanoparticles were modified by coating with polysorbate 80 to facilitate the crossing of the blood brain barrier (BBB), and the processing parameters (i.e. sonication time, the concentration of polymer (PLGA) and surfactant (polysorbate 80), and drug-polymer ratio) were optimized with the aim to achieve a high production yield. Brain targeting potential of the nanoparticles was evaluated by in vivo studies using Wistar albino rats. The nanoparticles produced by optimal formulation were within the nanosized range (70-200 nm) with relatively low polydispersity index (0.391 ± 1.2). The encapsulation efficiency of Bacoside-A in PLGA nanoparticles was 57.11 ± 7.11%, with a drug loading capacity of 20.5 ± 1.98%. SEM images showed the spherical shape of the PLGA nanoparticles, whereas their low crystallinity was demonstrated by X-ray studies, which also confirmed no chemical interactions between the drug and polymer molecules. The in vitro release of Bacoside-A from the PLGA nanoparticles followed a sustained release pattern with a maximum release of up to 83.04 ± 2.55% in 48 h. When compared to pure drug solution (2.56 ± 1.23 μg/g tissue), in vivo study demonstrated higher brain concentration of Bacoside-A (23.94 ± 1.74 μg/g tissue) suggesting a significant role of surface coated nanoparticles on brain targeting. The results indicate the potential of surface modified PLGA nanoparticles for the delivery of Bacoside-A to the brain.
Gupta, Swati; Agarwal, Abhinav; Gupta, Nishant Kumar; Saraogi, Gauravkant; Agrawal, Himanshu; Agrawal, G P
The present study explores prospective of surface tailored nanoparticles for targeted delivery of acyclovir along with the interception of minimal side effects. Acyclovir loaded plain and galactosylated poly lectic co glycolic acid (PLGA) nanoparticles were efficiently prepared and characterized by Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), size, polydispersity index, zeta potential, and entrapment efficiency. The formulations were evaluated for in vitro drug release and hemolysis. Further, biodistribution study and fluorescent microscopic studies were carried out to determine the targeting potential of formulations. SEM revealed smooth morphology and spherical shape of the nanoparticles. In vitro, the galactosylated nanoparticles were found to be least hemolytic and exhibited a sustained release pattern. In vivo studies exhibited an augmented bioavailability, increased residence time and enhanced delivery of acyclovir to the liver upon galactosylation. It may therefore be concluded that galactose conjugated PLGA nanoparticles can be used suitably as vehicles for delivery of bioactives specifically to the hepatic tissues and may be thus exploited in the effective management of various liver disorders.
Gwak, So-Jung; Yun, Yeomin; Yoon, Do Heum; Kim, Keung Nyun; Ha, Yoon
Gene delivery holds therapeutic promise for the treatment of neurological diseases and spinal cord injury. Although several studies have investigated the use of non-viral vectors, such as polyethylenimine (PEI), their clinical value is limited by their cytotoxicity. Recently, biodegradable poly (lactide-co-glycolide) (PLGA) nanospheres have been explored as non-viral vectors. Here, we show that modification of PLGA nanospheres with 3β-[N-(N′,N′-dimethylaminoethane) carbamoyl] cholesterol (DC-Chol) enhances gene transfection efficiency. PLGA/DC-Chol nanospheres encapsulating DNA were prepared using a double emulsion-solvent evaporation method. PLGA/DC-Chol nanospheres were less cytotoxic than PEI both in vitro and in vivo. DC-Chol modification improved the uptake of nanospheres, thereby increasing their transfection efficiency in mouse neural stem cells in vitro and rat spinal cord in vivo. Also, transgene expression induced by PLGA nanospheres was higher and longer-lasting than that induced by PEI. In a rat model of spinal cord injury, PLGA/DC-Chol nanospheres loaded with vascular endothelial growth factor gene increased angiogenesis at the injury site, improved tissue regeneration, and resulted in better recovery of locomotor function. These results suggest that DC-Chol-modified PLGA nanospheres could serve as therapeutic gene delivery vehicles for spinal cord injury. PMID:26824765
Gwak, So-Jung; Yun, Yeomin; Yoon, Do Heum; Kim, Keung Nyun; Ha, Yoon
Gene delivery holds therapeutic promise for the treatment of neurological diseases and spinal cord injury. Although several studies have investigated the use of non-viral vectors, such as polyethylenimine (PEI), their clinical value is limited by their cytotoxicity. Recently, biodegradable poly (lactide-co-glycolide) (PLGA) nanospheres have been explored as non-viral vectors. Here, we show that modification of PLGA nanospheres with 3β-[N-(N',N'-dimethylaminoethane) carbamoyl] cholesterol (DC-Chol) enhances gene transfection efficiency. PLGA/DC-Chol nanospheres encapsulating DNA were prepared using a double emulsion-solvent evaporation method. PLGA/DC-Chol nanospheres were less cytotoxic than PEI both in vitro and in vivo. DC-Chol modification improved the uptake of nanospheres, thereby increasing their transfection efficiency in mouse neural stem cells in vitro and rat spinal cord in vivo. Also, transgene expression induced by PLGA nanospheres was higher and longer-lasting than that induced by PEI. In a rat model of spinal cord injury, PLGA/DC-Chol nanospheres loaded with vascular endothelial growth factor gene increased angiogenesis at the injury site, improved tissue regeneration, and resulted in better recovery of locomotor function. These results suggest that DC-Chol-modified PLGA nanospheres could serve as therapeutic gene delivery vehicles for spinal cord injury.
Zhou, Ping; An, Tong; Zhao, Chuan; Li, Yuan; Li, Rongshan; Yang, Rui; Wang, Yinsong; Gao, Xiujun
The acidic internal pH environment, initial burst release and lack of targeting property are main limitations of poly(lactide-co-glycolide) (PLGA) nanoparticles for carrying proteins. In this study, ϵ-polylysine (ϵ-PL) was used as an anti-acidic agent and a protein protectant to prepare PLGA nanoparticles for the protein delivery. To obtain the liver-targeting capability, lactosylated PLGA (Lac-PLGA) was synthesized by conjugation of lactose acid to PLGA at both ends, and then used to prepare nanoparticles containing ϵ-PL by the nanoprecipitation method. Bovine serumal bumin (BSA), a negatively charged protein, was efficiently loaded into Lac-PLGA/ϵ-PL nanoparticles and exhibited significant decreased burst release in vitro, sustained release in the blood and increased liver distribution in mice after intravenous injections. The enhanced stability of BSA was due to its electrical interaction with ϵ-PL and the neutralized internal environment of nanoparticles. In conclusion, Lac-PLGA/ϵ-PL nanoparticle system can be used as a promising carrier for the negatively charged proteins.
Arias, José L; Unciti-Broceta, Juan D; Maceira, José; Del Castillo, Teresa; Hernández-Quero, José; Magez, Stefan; Soriano, Miguel; García-Salcedo, José A
Targeted delivery of therapeutics is an alternative approach for the selective treatment of infectious diseases. The surface of African trypanosomes, the causative agents of African trypanosomiasis, is covered by a surface coat consisting of a single variant surface glycoprotein, termed VSG. This coat is recycled by endocytosis at a very high speed, making the trypanosome surface an excellent target for the delivery of trypanocidal drugs. Here, we report the design of a drug nanocarrier based on poly ethylen glycol (PEG) covalently attached (PEGylated) to poly(D,L-lactide-co-glycolide acid) (PLGA) to generate PEGylated PLGA nanoparticles. This nanocarrier was coupled to a single domain heavy chain antibody fragment (nanobody) that specifically recognizes the surface of the protozoan pathogen Trypanosoma brucei. Nanoparticles were loaded with pentamidine, the first-line drug for T. b. gambiense acute infection. An in vitro effectiveness assay showed a 7-fold decrease in the half-inhibitory concentration (IC50) of the formulation relative to free drug. Furthermore, in vivo therapy using a murine model of African trypanosomiasis demonstrated that the formulation cured all infected mice at a 10-fold lower dose than the minimal full curative dose of free pentamidine and 60% of mice at a 100-fold lower dose. This nanocarrier has been designed with components approved for use in humans and loaded with a drug that is currently in use to treat the disease. Moreover, this flexible nanobody-based system can be adapted to load any compound, opening a range of new potential therapies with application to other diseases.
Gilert, Ariel; Baruch, Limor; Bronshtein, Tomer; Machluf, Marcelle
Strategies for cancer protein vaccination largely aim to activate the cellular arm of the immune system against cancer cells. This approach, however, is limited since protein vaccines mostly activate the system's humoral arm instead. One way to overcome this problem is to enhance the cross-presentation of such proteins by antigen-presenting cells, which may consequently lead to intense cellular response. Here we examined the ability of listeriolysin O (LLO) incorporated into poly-lactic-co-glycolic acid (PLGA) microspheres to modify the cytosolic delivery of low molecular weight peptides and enhance their cross-presentation. PLGA microspheres were produced in a size suitable for uptake by phagocytic cells. The peptide encapsulation and release kinetics were improved by adding NaCl to the preparation. PLGA microspheres loaded with the antigenic peptide and incorporated with LLO were readily up-taken by phagocytic cells, which exhibited an increase in the expression of peptide-MHC-CI complexes on the cell surface. Furthermore, this system enhanced the activation of a specific T hybridoma cell line, thus simulating cytotoxic T cells. These results establish, for the first time, a proof of concept for the use of PLGA microspheres incorporated with a pore-forming agent and the antigen peptide of choice as a unique cancer protein vaccination delivery platform.
Prabhakaran, Molamma P; Zamani, Maedeh; Felice, Betiana; Ramakrishna, Seeram
Advanced engineering of materials for the development of drug delivery devices provides scope for novel and versatile strategies for treatment of various diseases. 'Electrospraying' was used to prepare PLGA microparticles and further encapsulate the drug, metronidazole (Met) within the particles to function as a drug delivery system. Two different solvents were utilized for the preparation of drug loaded PLGA particles, whereby the polymeric solution in dichloromethane (DCM) produced particles of bigger sizes than using trifluoroethanol (TFE). Scanning electron microscopy showed the spherical morphology of the particles, with sizes of 3946±407nm and 1774±167nm, respectively for PLGA-Met(DCM) and PLGA-Met(TFE). The FTIR spectroscopy proved the incorporation of metronidazole in the polymer, but without any specific drug-polymer interaction. The release of the drug from the particles was studied in phosphate buffered saline, where a sustained drug release was obtained for at least 41days. Cytotoxicity evaluation of the drug extract using mesenchymal stem cells (MSCs) showed not hindering the proliferation of MSCs, and the cell phenotype was retained after incubation in the drug containing media. Electrospraying is suggested as a cost-effective and single step process for the preparation of polymeric microparticles for prolonged and controlled release of drug. Copyright © 2015 Elsevier B.V. All rights reserved.
Ranjbar-Mohammadi, Marziyeh; Zamani, M; Prabhakaran, M P; Bahrami, S Hajir; Ramakrishna, S
Controlled drug release is a process in which a predetermined amount of drug is released for longer period of time, ranging from days to months, in a controlled manner. In this study, novel drug delivery devices were fabricated via blend electrospinning and coaxial electrospinning using poly lactic glycolic acid (PLGA), gum tragacanth (GT) and tetracycline hydrochloride (TCH) as a hydrophilic model drug in different compositions and their performance as a drug carrier scaffold was evaluated. Scanning electron microscopy (SEM) results showed that fabricated PLGA, blend PLGA/GT and core shell PLGA/GT nanofibers had a smooth and bead-less morphology with the diameter ranging from 180 to 460 nm. Drug release studies showed that both the fraction of GT within blend nanofibers and the core-shell structure can effectively control TCH release rate from the nanofibrous membranes. By incorporation of TCH into core-shell nanofibers, drug release was sustained for 75 days with only 19% of burst release within the first 2h. The prolonged drug release, together with proven biocompatibility, antibacterial and mechanical properties of drug loaded core shell nanofibers make them a promising candidate to be used as drug delivery system for periodontal diseases.
Nasal vaccination with N-trimethyl chitosan and PLGA based nanoparticles: nanoparticle characteristics determine quality and strength of the antibody response in mice against the encapsulated antigen.
Slütter, Bram; Bal, Suzanne; Keijzer, Chantal; Mallants, Roel; Hagenaars, Niels; Que, Ivo; Kaijzel, Eric; van Eden, Willem; Augustijns, Patrick; Löwik, Clemens; Bouwstra, Joke; Broere, Femke; Jiskoot, Wim
Nasal vaccination is a promising, needle-free alternative to classical vaccination. Nanoparticulate delivery systems have been reported to overcome the poor immunogenicity of nasally administered soluble antigens, but the characteristics of the ideal particle are unknown. This study correlates differences in physicochemical characteristics of nanoparticles to their adjuvant effect, using ovalbumin (OVA)-loaded poly(lactic-co-glycolic acid) nanoparticles (PLGA NP), N-trimethyl chitosan (TMC) based NP (TMC NP) and TMC-coated PLGA NP (PLGA/TMC NP). PLGA NP and PLGA/TMC NP were prepared by emulsification/solvent extraction and TMC NP by ionic complexation. The NP were characterized physicochemically. Their toxicity and interaction with and stimulation of monocyte derived dendritic cells (DC) were tested in vitro. Furthermore, the residence time and the immunogenicity (serum IgG titers and secretory IgA levels in nasal washes) of the nasally applied OVA formulations were assessed in Balb/c mice. All NP were similar in size, whereas only PLGA NP carried a negative zeta potential. The NP were non-toxic to isolated nasal epithelium. Only TMC NP increased the nasal residence time of OVA compared to OVA administered in PBS and induced DC maturation. After i.m. administration all NP systems induced higher IgG titers than OVA alone, PLGA NP and TMC NP being superior to PLGA/TMC NP. Nasal immunization with the slow antigen releasing particles, PLGA NP and PLGA/TMC NP, did not induce detectable antibody titers. In contrast, nasal immunization with the positively charged, fast antigen releasing TMC NP led to high serum antibody titers and sIgA levels. In conclusion, particle charge and antigen release pattern of OVA-loaded NP has to be adapted to the intended route of administration. For nasal vaccination, TMC NP, releasing their content within several hours, being mucoadhesive and stimulating the maturation of DC, were superior to PLGA NP and PLGA/TMC NP which lacked some or all
Gruendel, Sindy; Otto, Baerbel; Garcia, Ada L; Wagner, Karen; Mueller, Corinna; Weickert, Martin O; Heldwein, Walter; Koebnick, Corinna
Dietary fibre consumption is associated with improved glucose homeostasis. In contrast, dietary polyphenols have been suggested to exert both beneficial and detrimental effects on glucose and insulin metabolism. Recently, we reported that a polyphenol-rich insoluble dietary fibre preparation from carob pulp (carob fibre) resulted in lower postprandial acylated ghrelin levels after a liquid meal challenge test compared with a control meal without supplementation. The effects may, however, differ when a different food matrix is used. Thus, we investigated the effects of carob fibre on glucose, insulin and ghrelin responses in healthy humans in combination with a glucose load. In a randomized single-blind cross-over study involving twenty healthy subjects (aged 22-62 years), plasma glucose, total and acylated ghrelin, and serum insulin were repeatedly assessed before and after the ingestion of 200 ml water with 50 g glucose and 0, 5, 10 or 20 g carob fibre over a period of 180 min. The intake of 5 and 10 g carob fibre increased the plasma glucose by 47 % and 64 % (P < 0.001), and serum insulin by 19.9 and 24.8 % (P < 0.001), compared with the control. Plasma acylated ghrelin concentrations did not change significantly after the consumption of carob-enriched glucose solution. Total ghrelin decreased only after 10 g carob fibre (P < 0.001) compared with control. In conclusion, we showed that polyphenol-rich carob fibre, administered within a water-glucose solution, increases postprandial glucose and insulin responses, suggesting a deterioration in glycaemic control.
Maenz, Stefan; Brinkmann, Olaf; Kunisch, Elke; Horbert, Victoria; Gunnella, Francesca; Bischoff, Sabine; Schubert, Harald; Sachse, Andre; Xin, Long; Günster, Jens; Illerhaus, Bernhard; Jandt, Klaus D; Bossert, Jörg; Kinne, Raimund W; Bungartz, Matthias
Injectable, brushite-forming calcium phosphate cements (CPC) show potential for bone replacement, but they exhibit low mechanical strength. This study tested a CPC reinforced with poly(l-lactide-co-glycolide) acid (PLGA) fibers in a minimally invasive, sheep lumbar vertebroplasty model. The study aimed to test the in vivo biocompatibility and osteogenic potential of a PLGA fiber-reinforced, brushite-forming CPC in a sheep large animal model. This is a prospective experimental animal study. Bone defects (diameter: 5 mm) were placed in aged, osteopenic female sheep, and left empty (L2) or injected with pure CPC (L3) or PLGA fiber-reinforced CPC (L4; fiber diameter: 25 µm; length: 1 mm; 10% [wt/wt]). Three and 9 months postoperation (n=20 each), the structural and functional CPC effects on bone regeneration were documented ex vivo by osteodensitometry, histomorphometry, micro-computed tomography (micro-CT), and biomechanical testing. Addition of PLGA fibers enhanced CPC osteoconductivity and augmented bone formation. This was demonstrated by (1) significantly enhanced structural (bone volume/total volume, shown by micro-CT and histomorphometry; 3 or 9 months) and bone formation parameters (osteoid volume and osteoid surface; 9 months); (2) numerically enhanced bone mineral density (3 and 9 months) and biomechanical compression strength (9 months); and (3) numerically decreased bone erosion (eroded surface; 3 and 9 months). The PLGA fiber-reinforced CPC is highly biocompatible and its PLGA fiber component enhanced bone formation. Also, PLGA fibers improve the mechanical properties of brittle CPC, with potential applicability in load-bearing areas. Copyright © 2016 Elsevier Inc. All rights reserved.
Imanparast, Fatemeh; Faramarzi, Mohammad Ali; Vatannejad, Akram; Paknejad, Maliheh; Deiham, Behnas; Kobarfard, Farzad; Amani, Amir; Doosti, Mahmood
Endothelial dysfunction is initial and critical step of atherosclerosis. Impaired bioavailability of endothelial nitric oxide synthase (eNOS) is one of the main reasons of endothelial dysfunction. Improving bioavailability of eNOS by increasing its expression or activity using statins is an effective therapeutic strategy in restoring endothelial dysfunction. In this study, simvastatin (SIM) as a poorly water-soluble drug was loaded in poly (lactic-co-glycolic acid) (PLGA) nanoparticles (SIM-PLGA-NPs). NPs were then conjugated with mZD7349 peptide (mZD7349-SIM-PLGA-NPs) and directed against vascular cell adhesion molecule 1 (VCAM-1). In vitro evaluation of the NPs for targeted delivery of SIM was performed on activated Human Umbilical Cord Vascular Endothelial Cells (HUVECs) by tumor necrosis factor alpha (TNF-α). Effect of mZD7349-SIM-PLGA-NPs and SIM-PLGA-NPs was compared on eNOS phosphorylation (ser-1177). Results of western blot showed SIM post-treatment increased significantly phosphor-eNOS (Ser1177) expression but no total eNOS expression. The study showed that mZD7349-SIM-PLGA-NPs have particle size, zeta potential value, polydispersity index (PDI) and encapsulation efficacy % of 233±18nm, -9.6±1.1mV, 0.59±0.066 and 69±17.3%, respectively. Also phosphor-eNOS (Ser1177) expression in activated HUVECs treated with mZD7349-SIM-PLGA-NPs was significantly (p<0.05) better than treated cells with SIM-PLGA-NPs. The results suggest that mZD7349-SIM-PLGA-NPs may be usable as an appropriate drug carrier for restoring endothelial dysfunction.
Clark, Amanda; Milbrandt, Todd A; Hilt, J Zach; Puleo, David A
The use of growth factors in tissue engineering offers an added benefit to cartilage regeneration. Growth factors, such as insulin-like growth factor I (IGF-I), increase cell proliferation and can therefore decrease the time it takes for cartilage tissue to regrow. In this study, IGF-I was released from poly(lactic-co-glycolic acid) (PLGA) scaffolds that were designed to have a decreased burst release often associated with tissue engineering scaffolds. The scaffolds were fabricated from IGF-I-loaded PLGA microspheres prepared by a double emulsion (W1/O/W2) technique. The microspheres were then compressed, sintered at 49 °C and salt leached. The bioactivity of soluble IGF-I was verified after being heat treated at 37, 43, 45, 49 and 60 °C. Additionally, the bioactivity of IGF-I was confirmed after being released from the sintered scaffolds. The triphasic release lasted 120 days resulting in 20%, 55% and 25% of the IGF-I being released during days 1-3, 4-58 and 59-120, respectively. Seeding bone marrow cells directly onto the IGF-I-loaded scaffolds showed an increase in cell proliferation, based on DNA content, leading to increased glycosaminoglycan production. The present results demonstrated that IGF-I remains active after being incorporated into heat-treated scaffolds, further enhancing tissue regeneration possibilities.
Lee, Jong Ho; Shin, Yong Cheol; Yang, Won Jun; Park, Jong-chul; Hyon, Suong-hyu; Han, Dong-wook
Epigallocatechin-3-O-gallate (EGCG), the main polyphenolic component of green tea, has a wide range of pharmacological activities, including antioxidant, anti-inflammatory, and anti-fibrotic effects. In this study, EGCG-loaded poly(lactic-co-glycolic acid) (PLGA) sheets were prepared by electrospinning nanofibers and evaluating their potential as tissue-adhesion barriers. EGCG-loaded PLGA (E-PLGA) fibrous sheets were electrospun from a PLGA solution containing 8% (w/v) EGCG. The average diameter of E-PLGA fibers was 397 ± 159 nm, which was comparable to that of pure PLGA fibers (459 ± 154 nm). EGCG was uniformly dispersed in E-PLGA sheets without direct chemical interactions. E-PLGA fibrous sheets showed sustained release of EGCG by controlled diffusion and PLGA degradation. The attachment and proliferation of L-929 fibroblastic cells were significantly (p < 0.05) suppressed in E-PLGA sheets. Furthermore, E-PLGA fibrous sheets did not induce any inflammatory response to J774A.1 macrophages. The anti-adhesion efficacy of E-PLGA fibrous sheets was evaluated in the intraperitoneal adhesion model in rats. Two weeks after surgical treatment, macroscopic adhesion (extent and severity) scores and histopathological tissue responses of E-PLGA fibrous sheets were significantly lower than those of non-treated controls and pure PLGA sheets. The results suggest that the scores are comparable, and in some cases superior, to those of other commercialized tissue-adhesion barriers. In conclusion, our study findings suggest that E-PLGA fibrous sheets may be exploited as potential tissue-adhesion barriers for the prevention of post-surgical adhesion formation.
Costa, Marcilia P; Feitosa, Anderson C S; Oliveira, Fátima C E; Cavalcanti, Bruno C; da Silva, Eufrânio N; Dias, Gleiston G; Sales, Francisco A M; Sousa, Bruno L; Barroso-Neto, Ito L; Pessoa, Cláudia; Caetano, Ewerton W S; Di Fiore, Stefano; Fischer, Rainer; Ladeira, Luiz O; Freire, Valder N
Prostate cancer is one of the most common malignant tumors in males and it has become a major worldwide public health problem. This study characterizes the encapsulation of Nor-β-lapachone (NβL) in poly(d,l-lactide-co-glycolide) (PLGA) microcapsules and evaluates the cytotoxicity of the resulting drug-loaded system against metastatic prostate cancer cells. The microcapsules presented appropriate morphological features and the presence of drug molecules in the microcapsules was confirmed by different methods. Spherical microcapsules with a size range of 1.03 ± 0.46 μm were produced with an encapsulation efficiency of approximately 19%. Classical molecular dynamics calculations provided an estimate of the typical adsorption energies of NβL on PLGA. Finally, the cytotoxic activity of NβL against PC3M human prostate cancer cells was demonstrated to be significantly enhanced when delivered by PLGA microcapsules in comparison with the free drug.
Zhang, Xingwang; Qi, Jianping; Lu, Yi; Hu, Xiongwei; He, Wei; Wu, Wei
Peroral protein/peptide delivery has been one of the most challenging, but encouraging topics in pharmaceutics. This article was intended to explore the potential of biotin-modified liposomes (BLPs) as oral insulin delivery carriers. By incorporating biotin-DSPE into the lipid bilayer, we prepared BLPs using reverse evaporation/sonication method. We investigated hypoglycemic effects in normal rats after oral administration of BLPs, and the possible absorption mechanism by a series of in vitro tests. The relative pharmacological bioavailability of BLPs was up to 11.04% that was as much as 5.28 folds of conventional liposomes (CLPs). The results showed that the enhanced oral absorption of insulin mainly attributed to biotin ligand-mediated endocytosis. The results provided proof of BLPs as effective carriers for oral insulin delivery.
Castex, C; Donnio, R; Sutter, B C
Glucose tolerance tests made in the Edible dormouse showed annual variations in B cell secretory capacity, associated with glucose tolerance changes. 1. During autumn and winter, the B cell is sensitive to glucose, and insulin regulates the high peripheral consumption of this hexose. 2. At the beginning of spring, insulin secretion decreases and glucose tolerance is impaired. In June, the B cell response si low or absent and a poor tolerance to glucose still persists. 3. The variations in B cell activity can be related to changing energy requirements during the year.
Gu, Bing; Burgess, Diane J
Hydrophobic drug release from poly (lactic-co-glycolic acid) (PLGA) microspheres typically exhibits a tri-phasic profile with a burst release phase followed by a lag phase and a secondary release phase. High burst release can be associated with adverse effects and the efficacy of the formulation cannot be ensured during a long lag phase. Accordingly, the development of a long-acting microsphere product requires optimization of all drug release phases. The purpose of the current study was to investigate whether a blend of low and high molecular weight polymers can be used to reduce the burst release and eliminate/minimize the lag phase. A single emulsion solvent evaporation method was used to prepare microspheres using blends of two PLGA polymers (PLGA5050 (25 kDa) and PLGA9010 (113 kDa)). A central composite design approach was applied to investigate the effect of formulation composition on dexamethasone release from these microspheres. Mathematical models obtained from this design of experiments study were utilized to generate a design space with maximized microsphere drug loading and reduced burst release. Specifically, a drug loading close to 15% can be achieved and a burst release less than 10% when a composition of 80% PLGA9010 and 90 mg of dexamethasone is used. In order to better describe the lag phase, a heat map was generated based on dexamethasone release from the PLGA microsphere/PVA hydrogel composite coatings. Using the heat map an optimized formulation with minimum lag phase was selected. The microspheres were also characterized for particle size/size distribution, thermal properties and morphology. The particle size was demonstrated to be related to the polymer concentration and the ratio of the two polymers but not to the dexamethasone concentration.
Runchey, Shauna S.; Pollak, Michael N.; Valsta, Liisa M.; Coronado, Gloria D.; Schwarz, Yvonne; Breymeyer, Kara L.; Wang, Chiachi; Wang, Ching-Yun; Lampe, Johanna W.; Neuhouser, Marian L.
Background/Objectives The effect of a low glycemic load (GL) diet on insulin-like growth factor-1 (IGF-1) concentration is still unknown but may contribute to lower chronic disease risk. We aimed to assess the impact of GL on concentrations of IGF-1 and IGFBP-3. Subjects/Methods We conducted a randomized, controlled crossover feeding trial in 84 overweight-obese and normal weight healthy individuals using two 28-day weight-maintaining high- and low-GL diets. Measures were fasting and post-prandial concentrations of insulin, glucose, IGF-1 and IGFBP-3. 20 participants completed post-prandial testing by consuming a test breakfast at the end of each feeding period. We used paired t-tests for diet-component and linear mixed models for biomarker analyses. Results The 28-day low-GL diet led to 4% lower fasting concentrations of IGF-1 (10.6 ng/mL, p=0.04) and a 4% lower ratio of IGF-1/IGFBP-3 (0.24, p=0.01) compared to the high-GL diet. The low-GL test breakfast led to 43% and 27% lower mean post-prandial glucose and insulin responses, respectively; mean incremental areas under the curve for glucose and insulin, respectively, were 64.3±21.8 (mmol/L/240min) (p<0.01) and 2253±539 (μU/mL/240min) (p<0.01) lower following the low- compared to the high-GL test meal. There was no effect of GL on mean HOMA-IR or on mean integrated post-prandial concentrations of glucose-adjusted insulin, IGF-1 or IGFBP-3. We did not observe modification of the dietary effect by adiposity. Conclusions Low-GL diets resulted in 43% and 27% lower post-prandial responses of glucose and insulin, respectively, and modestly lower fasting IGF-1 concentrations. Further intervention studies are needed to weigh the impact of dietary GL on risk for chronic disease. PMID:22892437
Milacic, Vesna; Schwendeman, Steven P.
Purpose We evaluated the controlled release lysozyme from various poly(D,L-lactic-co-glycolic acid) (PLGA) 50/50-polyethylene glycol (PEG) block copolymers relative to PLGA 50/50. Methods Lysozyme was encapsulated in cylindrical implants (0.8 mm diameter) by a solvent extrusion method. Release studies were conducted in phosphate buffered saline + 0.02 % Tween 80 (PBST) at 37°C. Lysozyme activity was measured by a fluorescence-based assay. Implant erosion was evaluated by kinetics of polymer molecular weight decline, water uptake, and mass loss. Results Lysozyme release from an AB15 di-block copolymer (15% 5 kDa PEG, PLGA 28 kDa) was very fast, whereas an AB10 di-block copolymer (with 10% 5 kDa PEG, PLGA 45 kDa) and ABA10 tri-block copolymer (with 10% 6 kDa PEG, PLGA 27kDa) showed release profiles similar to PLGA. We achieved continuous lysozyme release for up to 4 weeks from AB10 and ABA10 by lysozyme co-encapsulation with the pore- forming and acid-neutralizing MgCO3, and from AB15 by co-encapsulation of MgCO3 and blending AB15 with PLGA. Lysozyme activity was mostly recovered during four weeks. Conclusions These block co-polymers may have utility either alone or as PLGA blends for the controlled release of proteins. PMID:23959854
Wang, Qun; Wang, Jinxi; Lu, Qinghua; Detamore, Michael Scott; Berkland, Cory
Bone fillers have emerged as an alternative to the invasive surgery often required to repair skeletal defects. Achieving controlled release from these materials is desired for accelerating healing. Here, oppositely-charged Poly (D,L-lactic-co-glycolic acid) (PLGA) nanoparticles were used to create a cohesive colloidal gel as an injectable drug-loaded filler to promote healing in bone defects. The colloid self-assembled through electrostatic forces resulting in a stable 3-D network that may be extruded or molded to the desired shape. The colloidal gel demonstrated shear-thinning behavior due to the disruption of interparticle interactions as the applied shear force was increased. Once the external force was removed, the cohesive property of the colloidal gel was recovered. Similar reversibility and shear-thinning behavior were also observed in colloidal gels loaded with dexamethasone. Near zero-order dexamethasone release was observed over two months when the drug was encapsulated in PLGA nanoparticles and simply blending the drug with the colloidal gel showed similar kinetics for one month. Surgical placement was facilitated by the pseudoplastic material properties and in vivo observations demonstrated that the PLGA colloidal gels stimulated osteoconductive bone formation in rat cranial bone defects. (c) 2010 Elsevier Ltd. All rights reserved.
Wang, Qun; Wang, Jinxi; Lu, Qinghua; Detamore, Michael S.; Berkland, Cory
Bone fillers have emerged as an alternative to the invasive surgery often required to repair skeletal defects. Achieving controlled release from these materials is desired for accelerating healing. Here, oppositely-charged Poly (d,l-lactic-co-glycolic acid) (PLGA) nanoparticles were used to create a cohesive colloidal gel as an injectable drug-loaded filler to promote healing in bone defects. The colloid self-assembled through electrostatic forces resulting in a stable 3-D network that may be extruded or molded to the desired shape. The colloidal gel demonstrated shear-thinning behavior due to the disruption of interparticle interactions as the applied shear force was increased. Once the external force was removed, the cohesive property of the colloidal gel was recovered. Similar reversibility and shear-thinning behavior were also observed in colloidal gels loaded with dexamethasone. Near zero-order dexamethasone release was observed over two months when the drug was encapsulated in PLGA nanoparticles and simply blending the drug with the colloidal gel showed similar kinetics for one month. Surgical placement was facilitated by the pseudoplastic material properties and in vivo observations demonstrated that the PLGA colloidal gels stimulated osteoconductive bone formation in rat cranial bone defects. PMID:20303585
Bonelli, Patrizia; Tuccillo, Franca M; Federico, Antonella; Napolitano, Maria; Borrelli, Antonella; Melisi, Daniela; Rimoli, Maria G; Palaia, Raffaele; Arra, Claudio; Carinci, Francesco
Purpose Epidemiological, clinical, and laboratory studies have suggested that ibuprofen, a commonly used nonsteroidal anti-inflammatory drug, inhibits the promotion and proliferation of certain tumors. Recently, we demonstrated the antiproliferative effects of ibuprofen on the human gastric cancer cell line MKN-45. However, high doses of ibuprofen were required to elicit these antiproliferative effects in vitro. The present research compared the antiproliferative effects of ibuprofen delivered freely and released by poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) in MKN-45 cells. Methods MKN-45 human gastric adenocarcinoma cells were treated with ibuprofen-loaded PLGA NPs. The proliferation of MKN-45 cells was then assessed by cell counting. The uptake of NPs was imaged by fluorescence microscopy and flow cytometry. The release of ibuprofen from ibuprofen-loaded PLGA NPs in the cells was evaluated by gas chromatography–mass spectrometry. Results Dramatic inhibition of cellular proliferation was observed in cells treated with ibuprofen-loaded PLGA NPs versus those treated with free ibuprofen at the same concentration. The localization of NPs was cytoplasmic. The initiation of ibuprofen release was rapid, commencing within 2 hours, and then increased slowly over time, reaching a maximum concentration at 24 hours. The inhibition of proliferation was confirmed to be due to the intracellular release of ibuprofen from the NPs. Using PLGA NPs as carriers, ibuprofen exerted an antiproliferative activity at concentrations > 100 times less than free ibuprofen, suggesting greater efficiency and less cellular toxicity. In addition, when carried by PLGA NPs, ibuprofen more quickly induced the expression of transcripts involved in proliferation and invasiveness processes. Conclusion Ibuprofen exerted an antiproliferative effect on MKN-45 cells at low concentrations. This effect was achieved using PLGA NPs as carriers of low doses of ibuprofen. PMID:23180963
Chien, Chiang-Ting; Jou, Ming-Jia; Cheng, Tai-Yu; Yang, Chih-Hui; Yu, Tzu-Ying; Li, Ping-Chia
Glucagon-like peptide-1 (GLP-1) receptor activation in the brain provides neuroprotection. Exendin-4 (Ex-4), a GLP-1 analog, has seen limited clinical usage because of its short half-life. We developed long-lasting Ex-4-loaded poly(D,L-lactide-co-glycolide) microspheres (PEx-4) and explored its neuroprotective potential against cerebral ischemia in diabetic rats. Compared with Ex-4, PEx-4 in the gradually degraded microspheres sustained higher Ex-4 levels in the plasma and cerebrospinal fluid for at least 2 weeks and improved diabetes-induced glycemia after a single subcutaneous administration (20 μg/day). Ten minutes of bilateral carotid artery occlusion (CAO) combined with hemorrhage-induced hypotension (around 30 mm Hg) significantly decreased cerebral blood flow and microcirculation in male Wistar rats subjected to streptozotocin-induced diabetes. CAO increased cortical O2− levels by chemiluminescence amplification and prefrontal cortex edema by T2-weighted magnetic resonance imaging analysis. CAO significantly increased aquaporin 4 and glial fibrillary acidic protein expression and led to cognition deficits. CAO downregulated phosphorylated Akt/endothelial nitric oxide synthase (p-Akt/p-eNOS) signaling and enhanced nuclear factor (NF)-κBp65/intercellular adhesion molecule-1 (ICAM-1) expression, endoplasmic reticulum (ER) stress, and apoptosis in the cerebral cortex. PEx-4 was more effective than Ex-4 to improve CAO-induced oxidative injury and cognitive deficits. The neuroprotection provided by PEx-4 was through p-Akt/p-eNOS pathways, which suppressed CAO-enhanced NF-κB/ICAM-1 signaling, ER stress, and apoptosis. PMID:26058696
Ortega-Oller, Inmaculada; Padial-Molina, Miguel; Galindo-Moreno, Pablo; O'Valle, Francisco; Jódar-Reyes, Ana Belén; Peula-García, Jose Manuel
Poly-lactic-co-glycolic acid (PLGA) is one of the most widely used synthetic polymers for development of delivery systems for drugs and therapeutic biomolecules and as component of tissue engineering applications. Its properties and versatility allow it to be a reference polymer in manufacturing of nano- and microparticles to encapsulate and deliver a wide variety of hydrophobic and hydrophilic molecules. It additionally facilitates and extends its use to encapsulate biomolecules such as proteins or nucleic acids that can be released in a controlled way. This review focuses on the use of nano/microparticles of PLGA as a delivery system of one of the most commonly used growth factors in bone tissue engineering, the bone morphogenetic protein 2 (BMP2). Thus, all the needed requirements to reach a controlled delivery of BMP2 using PLGA particles as a main component have been examined. The problems and solutions for the adequate development of this system with a great potential in cell differentiation and proliferation processes under a bone regenerative point of view are discussed. PMID:26509156
Ortega-Oller, Inmaculada; Padial-Molina, Miguel; Galindo-Moreno, Pablo; O'Valle, Francisco; Jódar-Reyes, Ana Belén; Peula-García, Jose Manuel
Poly-lactic-co-glycolic acid (PLGA) is one of the most widely used synthetic polymers for development of delivery systems for drugs and therapeutic biomolecules and as component of tissue engineering applications. Its properties and versatility allow it to be a reference polymer in manufacturing of nano- and microparticles to encapsulate and deliver a wide variety of hydrophobic and hydrophilic molecules. It additionally facilitates and extends its use to encapsulate biomolecules such as proteins or nucleic acids that can be released in a controlled way. This review focuses on the use of nano/microparticles of PLGA as a delivery system of one of the most commonly used growth factors in bone tissue engineering, the bone morphogenetic protein 2 (BMP2). Thus, all the needed requirements to reach a controlled delivery of BMP2 using PLGA particles as a main component have been examined. The problems and solutions for the adequate development of this system with a great potential in cell differentiation and proliferation processes under a bone regenerative point of view are discussed.
Sun, Fengying; Sui, Cheng; Teng, Lesheng; Liu, Ximing; Teng, Lirong; Meng, Qingfan; Li, Youxin
In this study, poly(d,l-lactide-co-glycolide) (PLGA) microspheres of tolterodine depot formulation were prepared using oil in water (o/w) method to investigate their potential pharmacokinetic and pharmacodynamic advantages over tolterodine l-tartrate tablets. Morphological studies of the microspheres showed a spherical shape and smooth surface with mean size of 50.69-83.01 microm, and the encapsulation efficiency was improved from 62.55 to 79.10% when the polymer concentration increased from 180 to 230 mg/ml. The addition of stearic or palmitic acids could significantly raise the drug entrapment efficiency but only slightly affected the in vitro release. A low initial burst followed by a proximately constant release of tolterodine was noticed in the in vitro release profiles. The in vivo study was carried out by intramuscular (i.m.) administration of tolterodine-loaded microspheres on beagle dogs, and a sustained release of drug from the PLGA microspheres was achieved until the 18th day with a low initial burst. Since the absence of hepatic first pass metabolism, only a single active compound-tolterodine was detected in the plasma. This avoided the coexistence of two active compounds in plasma in the case of oral administration of tolterodine, which may lead to a difficulty in dose control due to the different metabolic capacity of patients. In the pharmacodynamic study, the influence of tolterodine PLGA microspheres on the inhibition of carbachol-induced rat urinary bladder contraction was more significant than that of tolterodine l-tartrate tablets. There were invisible changes in rat bladder slices between tolterodine-loaded PLGA microspheres group and tolterodine l-tartrate tablets group. These results indicate that the continuous inhibition of muscarinic receptor may offer an alternative therapy of urge incontinence.
Pignatello, Rosario; Cenni, Elisabetta; Micieli, Dorotea; Fotia, Caterina; Salerno, Manuela; Granchi, Donatella; Avnet, Sofia; Sarpietro, Maria G; Castelli, Francesco; Baldini, Nicola
Osteotropic drug-delivery systems have been proposed as a means to provide drugs with affinity to bone tissues. Drugs or proteins have been linked chemically to bone-seeking agents, such as bisphosphonates (BPs); alternatively, drug-loaded nanoparticles have been used to target specific tissues, such as tumor areas. In our current research, these approaches were merged by synthesizing a novel bone-seeking polymer conjugate, from which targetable nanoparticles can be produced. An amino-BP, alendronate (ALE) was bound covalently to a biodegradable polymer, poly(lactic-co-glycolide) (PLGA), containing a free end carboxylic group. Blood compatibility and cytotoxicity were assessed in vitro. By a classical solvent-evaporation method, nanoparticles with a mean size of 200-300 nm were prepared from the conjugate; sterilization was achieved by gamma-irradiation, confirming their potential as injectable drug nanocarriers. Owing to the presence of the BP residue, PLGA-ALE nanoparticles were adsorbed onto hydroxyapatite to a higher extent than pure PLGA nanoparticles. The PLGA-ALE conjugate did not induce either hemolysis or alterations of the plasmatic phase of coagulation, or cytotoxic effects on endothelial cells and trabecular osteoblasts. The prepared conjugate represents a novel biomaterial that is able to provide nanoparticles, which can be further loaded with drugs, such as anticancer agents, and addressed to osteolytic or other bone diseases.
Katsikogianni, Georgia; Avgoustakis, Konstantinos
In this work, the drug loading and in vitro release properties of PLGA-mPEG nanoparticles were studied. Three methyl-xanthine derivatives differing significantly in aqueous solubility, i.e., caffeine, theophylline, and theobromine, were employed as model drugs. Two different PLGA-mPEG copolymer compositions, namely PLGA(40)mPEG(5) and PLGA(136)mPEG(5), were included in the study. The nanoparticles were prepared by a double emulsion technique. The drug release properties of the nanoparticles in phosphate buffered saline (PBS) and in human plasma were determined. An increase of the drug proportion in the feed led to increased drug loading. The composition of the PLGA-mPEG copolymer (PLGA/mPEG molar ratio) did not appear to affect drug loading and encapsulation. Caffeine exhibited higher loading in the nanoparticles than theobromine and this exhibited a little higher loading than theophylline. Solid-state solubility of the drug in PLGA-mPEG did not affect drug loading. Drug loading and encapsulation in the PLGA-mPEG nanoparticles appeared to be governed by the partition coefficient of the drug between the organic phase and the external aqueous phase employed in nanoparticle preparation. Relatively low loading and encapsulation values were obtained, suggesting that the physical entrapment of drugs in PLGA-mPEG nanoparticles could only be an option in the development of formulations of potent drugs. Only the release of the least water-soluble theobromine was efficiently sustained by its entrapment in the nanoparticles, indicating that the physical entrapment of drugs provides the means for the development of controlled-release PLGA-mPEG nanoparticulate formulations only in the case of drugs with low aqueous solubility.
Tseng, Yuan-Yun; Su, Chen-Hsing; Yang, Shun-Tai; Huang, Yin-Chen; Lee, Wei-Hwa; Wang, Yi-Chuan; Liu, Shou-Cheng; Liu, Shih-Jung
Glioblastoma multiforme (GBM), the most prevalent and malignant form of a primary brain tumour, is resistant to chemotherapy. In this study, we concurrently loaded three chemotherapeutic agents [bis-chloroethylnitrosourea, irinotecan, and cisplatin; BIC] into 50:50 poly[(d,l)-lactide-co-glycolide] (PLGA) nanofibres and an antiangiogenic agent (combretastatin) into 75:25 PLGA nanofibres [BIC and combretastatin (BICC)/PLGA]. The BICC/PLGA nanofibrous membranes were surgically implanted onto the brain surfaces of healthy rats for conducting pharmacodynamic studies and onto C6 glioma-bearing rats for estimating the therapeutic efficacy. The chemotherapeutic agents were rapidly released from the 50:50 PLGA nanofibres after implantation, followed by the release of combretastatin (approximately 2 weeks later) from the 75:25 PLGA nanofibres. All drug concentrations remained higher in brain tissues than in the blood for more than 8 weeks. The experimental results, including attenuated malignancy, retarded tumour growth, and prolonged survival in tumour-bearing rats, demonstrated the efficacy of the BICC/PLGA nanofibrous membranes. Furthermore, the efficacy of BIC/PLGA and BICC/PLGA nanofibrous membranes was compared. The BICC/PLGA nanofibrous membranes more efficiently retarded the tumour growth and attenuated the malignancy of C6 glioma-bearing rats. Moreover, the addition of combretastatin did not significantly change the drug release behaviour of the BIC/PLGA nanofibrous membranes. The present advanced and novel interstitial chemotherapy and targeted treatment provide a potential strategy and regimen for treating GBM. PMID:27494894
Sharma, Garima; Sharma, Ashish Ranjan; Nam, Ju-Suk; Doss, George Priya C; Lee, Sang-Soo; Chakraborty, Chiranjib
Diabetic cases have increased rapidly in recent years throughout the world. Currently, for type-1 diabetes mellitus (T1DM), multiple daily insulin (MDI) injections is the most popular treatment throughout the world. At this juncture, researchers are trying to develop different insulin delivery systems, especially through oral and pulmonary route using nanocarrier based delivery system. This next generation efficient therapy for T1DM may help to improve the quality of life of diabetic patients who routinely employ insulin by the subcutaneous route. In this paper, we have depicted various next generation nanocarrier based insulin delivery systems such as chitosan-insulin nanoparticles, PLGA-insulin nanoparticles, dextran-insulin nanoparticles, polyalkylcyanoacrylated-insulin nanoparticles and solid lipid-insulin nanoparticles. Modulation of these insulin nanocarriers may lead to successful oral or pulmonary insulin nanoformulations in future clinical settings. Therefore, applications and limitations of these nanoparticles in delivering insulin to the targeted site have been thoroughly discussed.
Subhash, Hrebesh M.; Xie, Hui; Smith, Jeffrey W.; McCarty, Owen
Nanoparticles with plasmon-resonance absorption in the near-IR (NIR) optical range are of great interest in optical coherence tomography (OCT) for contrast enhancement and diagnostic interventions in molecular imaging. In this study, we characterized the optical properties of multifunctional NIR dye-loaded PLGA nanoparticles (approved by the U.S. Food and Drug Administration) to assess the feasibility of using contrast agent for photo-thermal OCT (PT-OCT) imaging. Tissue phantoms containing NIR dye-doped PLGA nanoparticles were prepared in 2% agarose solution. To study the feasibility of detecting the particles using PT-OCT, imaging was performed with a custom built PT-OCT system, and specific contrast was obtained with the prepared tissue mimicking phantoms. The excellent photo-thermal properties in combination with the positive tissue phantom results qualify the feasibility of dye-loaded PLGA particles as promising candidate for PT-OCT imaging applications.
Liu, Ying; Wu, Xin; Mi, Yushuai; Zhang, Bimeng; Gu, Shengying; Liu, Gaolin; Li, Xiaoyu
This article reports a promising approach to enhance the oral delivery of nuciferine (NUC), improve its aqueous solubility and bioavailability, and allow its controlled release as well as inhibiting lipid accumulation. NUC-loaded poly lactic-co-glycolic acid nanoparticles (NUC-PLGA-NPs) were prepared according to a solid/oil/water (s/o/w) emulsion technique due to the water-insolubility of NUC. PLGA exhibited excellent loading capacity for NUC with adjustable dosing ratios. The drug loading and encapsulation efficiency of optimized formulation were 8.89 ± 0.71 and 88.54 ± 7.08%, respectively. NUC-PLGA-NPs exhibited a spherical morphology with average size of 150.83 ± 5.72 nm and negative charge of -22.73 ± 1.63 mV, which are suitable for oral administration. A sustained NUC released from NUC-PLGA-NPs with an initial exponential release owing to the surface associated drug followed by a slower release of NUC, which was entrapped in the core. In addition, ∼77 ± 6.67% was released in simulating intestinal juice, while only about 45.95 ± 5.2% in simulating gastric juice. NUC-PLGA-NPs are more efficient against oleic acid (OA)-induced hepatic steatosis in HepG2 cells when compared to naked NUC (n-NUC, *p < 0.05). The oral bioavailability of NUC-PLGA-NPs group was significantly higher (**p < 0.01) and a significantly decreased serum levels of total cholesterol (TC), triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C), as well as a higher concentration of high-density lipoprotein cholesterol (HDL-C) was observed, compared with that of n-NUC treated group. These findings suggest that NUC-PLGA-NPs hold great promise for sustained and controlled drug delivery with improved bioavailability to alleviating lipogenesis.
Hafner, Annina M; Corthésy, Blaise; Textor, Marcus; Merkle, Hans P
Biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres are potential vehicles to deliver antigens for vaccination. Because they lack the full capacity to activate professional antigen presenting cells (APCs), combination with an immunostimulatory adjuvant may be considered. A candidate is the synthetic TLR3 ligand polyriboinosinic acid-polyribocytidylic acid, poly(I:C), which drives cell-mediated immunity. However, poly(I:C) has also been linked to the pathogenesis of autoimmunity, as affected by widespread stimulation of non-hematopoietic bystander cells. To address this aspect, we propose to minimize the poly(I:C) dose as well as to control the stimulation of non-immune bystander cells by poly(I:C). To facilitate the maturation of APCs with minimal poly(I:C) doses, we surface-assembled poly(I:C) onto PLGA microspheres. The microspheres' surface was further modified by poly(ethylene glycol) (PEG) coronas with varying PEG-densities. PLGA microspheres loaded with tetanus toxoid (tt) as model antigen were manufactured by microextrusion-based solvent extraction. The negatively charged PLGA(tt) microspheres were coated with polycationic poly(l-lysine) (PLL) polymers, either PLL itself or PEG-grafted PLL (PLL-g-PEG) with varying grafting ratios (g=2.2 and g=10.1). Stable surface assembly of poly(I:C) was achieved by subsequent incubation of polymer-coated PLGA microspheres with aqueous poly(I:C) solutions. We evaluated the immunostimulatory potential of such PLGA(tt) microsphere formulations on monocyte-derived dendritic cells (MoDCs) as well as human foreskin fibroblasts (HFFs) as model for non-hematopoietic bystander cells. Formulations with surface-assembled poly(I:C) readily activated MoDCs with respect to the expression of maturation-related surface markers, proinflammatory cytokine secretion and directed migration. When surface-assembled, poly(I:C) enhanced its immunostimulatory activity by more than one order of magnitude as compared to free poly
Navarro, Sara M; Darensbourg, Caleb; Cross, Linda; Stout, Rhett; Coulon, Diana; Astete, Carlos E; Morgan, Timothy; Sabliov, Cristina M
Aim To quantify in vivo the biodistribution of poly(lactic-co-glycolic) acid (PLGA) and PLGA/chitosan nanoparticles (PLGA/Chi NPs) and assess if the positive charge of chitosan significantly enhances nanoparticle absorption in the GI tract. Material & methods PLGA and PLGA/Chi NPs covalently linked to tetramethylrhodamine-5-isothiocyanate (TRITC) were orally administered to F344 rats for 7 days, and the biodistribution of fluorescent NPs was analyzed in different organs. Results The highest amount of particles (% total dose/g) was detected for both treatments in the spleen, followed by intestine and kidney, and then by liver, lung, heart and brain, with no significant difference between PLGA and PLGA/Chi NPs. Conclusion Only a small percentage of orally delivered NPs was detected in the analyzed organs. The positive charge conferred by chitosan was not sufficient to improve the absorption of the PLGA/Chi NPs over that of PLGA NPs. PMID:25491670
Intra, Janjira; Salem, Aliasger K
We report, for the first time, on the preparation, characterization and in vitro testing of poly(D,L-lactide-co-glycolide) (PLGA) microparticles loaded with polyamidoamine (PAMAM)-plasmid DNA (pDNA) dendriplexes. Loading of pDNA into the PLGA microparticles increased by 150% when pDNA was first complexed with PAMAM dendrimers relative to loading of pDNA alone. Scanning electron microscopy (SEM) showed that the presence of PAMAM dendrimers in the PLGA microparticles created porous features and indentations on the surface of the microparticles. Loading PLGA microparticles with PAMAM-pDNA dendriplexes lowered the average PLGA microparticle size and changed the surface charge of the microparticles from negative to positive when compared to PLGA microparticles loaded with pDNA alone. The zetapotential and buffering capacity of the microparticles increased as the generation of the PAMAM dendrimer loaded in the PLGA microparticles increased. Gel electrophoresis assays showed that all the PLGA microparticle formulations were able to entrap the pDNA within the PLGA matrix. There was no significant difference in the cytotoxicity of PLGA microparticles loaded with PAMAM-pDNA dendriplexes when compared to PLGA microparticles loaded with pDNA alone. Furthermore, and in contrast to PAMAM dendrimers alone, the generation of the PAMAM dendrimer loaded in the PLGA microparticles had no significant impact on cytotoxicity or transfection efficiencies in human embryonic kidney (HEK293) or Monkey African green kidney fibroblast-like (COS7) cells. The transfection efficiency of PLGA microparticles loaded with generation 3 (G3) PAMAM-pDNA dendriplexes was significantly higher than PLGA microparticles loaded with pDNA alone in HEK293 and COS7 cells. PLGA microparticles loaded with G3 PAMAM-pDNA dendriplexes generated equivalent transfection efficiencies as (G3 to G6) PAMAM-pDNA dendriplexes alone in COS7 cells when the transfection was carried out in serum containing media. The delivery
Tong, Fei; Tang, Xiangyuan; Li, Xin; Xia, Wenquan; Liu, Daojun
The aim of this study was to observe the therapeutic effect of insulin-loaded linear poly(ethylene glycol)-brush-like poly(l-lysine) block copolymer poly(ethylene glycol)-b-(poly(ethylenediamine l-glutamate)-g-poly(l-lysine)) (PEG-b-(PELG-g-PLL) on renal ischemia/reperfusion-induced lung injury through downregulating hypoxia-inducible factor (HIF) as compared to free insulin. Sprague Dawley rats were pretreated with 30 U/kg insulin or insulin/PEG-b-(PELG-g-PLL) complex, and then subjected to 45 minutes of ischemia and 24 hours of reperfusion. The blood and lungs were collected, the level of serum creatinine and blood urea nitrogen were measured, and the dry/wet lung ratios, the activity of superoxide dismutase and myeloperoxidase, the content of methane dicarboxylic aldehyde and tumor necrosis factor-α, and the expression of HIF-1α and vascular endothelial growth factor (VEGF) were measured in pulmonary tissues. Both insulin and insulin/PEG-b-(PELG-g-PLL) preconditioning improved the recovery of renal function, reduced pulmonary oxidative stress injury, restrained inflammatory damage, and downregulated the expression of HIF-1α and VEGF as compared to ischemia/reperfusion group, while insulin/PEG-b-(PELG-g-PLL) significantly improved this effect.
Chhabra, Resham; Grabrucker, Andreas M; Veratti, Patrizia; Belletti, Daniela; Boeckers, Tobias M; Vandelli, Maria Angela; Forni, Flavio; Tosi, Giovanni; Ruozi, Barbara
Polymeric nanoparticles (NPs) offer a promising approach for therapeutic intracellular delivery of proteins, conventionally hampered by short half-lives, instability and immunogenicity. Remarkably, NPs uptake occurs via endocytic internalization leading to NPs content's release within lysosomes. To overcome lysosomal degradation and achieve NPs and/or loaded proteins release into cytosol, we propose the formulation of hybrid NPs by adding 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) as pH sensitive component in the formulation of poly-lactide-co-glycolide (PLGA) NPs. Hybrid NPs, featured by different DOPE/PLGA ratios, were characterized in terms of structure, stability and lipid organization within the polymeric matrix. Experiments on NIH cells and rat primary neuronal cultures highlighted the safety profile of hybrid NPs. Moreover, after internalization, NPs are able to transiently destabilize the integrity of lysosomes in which they are taken up, speeding their escape and favoring cytoplasmatic localization. Thus, these DOPE/PLGA-NPs configure themselves as promising carriers for intracellular protein delivery. Copyright © 2014 Elsevier B.V. All rights reserved.
Shen, Jie; Lee, Kyulim; Choi, Stephanie; Qu, Wen; Wang, Yan; Burgess, Diane J
The objective of the present study was to develop a discriminatory and reproducible accelerated in vitro release method for long-acting PLGA microspheres with inner structure/porosity differences. Risperidone was chosen as a model drug. Qualitatively and quantitatively equivalent PLGA microspheres with different inner structure/porosity were obtained using different manufacturing processes. Physicochemical properties as well as degradation profiles of the prepared microspheres were investigated. Furthermore, in vitro release testing of the prepared risperidone microspheres was performed using the most common in vitro release methods (i.e., sample-and-separate and flow through) for this type of product. The obtained compositionally equivalent risperidone microspheres had similar drug loading but different inner structure/porosity. When microsphere particle size appeared similar, porous risperidone microspheres showed faster microsphere degradation and drug release compared with less porous microspheres. Both in vitro release methods investigated were able to differentiate risperidone microsphere formulations with differences in porosity under real-time (37 °C) and accelerated (45 °C) testing conditions. Notably, only the accelerated USP apparatus 4 method showed good reproducibility for highly porous risperidone microspheres. These results indicated that the accelerated USP apparatus 4 method is an appropriate fast quality control tool for long-acting PLGA microspheres (even with porous structures).
Pakulska, Malgosia M.; Elliott Donaghue, Irja; Obermeyer, Jaclyn M.; Tuladhar, Anup; McLaughlin, Christopher K.; Shendruk, Tyler N.; Shoichet, Molly S.
Encapsulation of therapeutic molecules within polymer particles is a well-established method for achieving controlled release, yet challenges such as low loading, poor encapsulation efficiency, and loss of protein activity limit clinical translation. Despite this, the paradigm for the use of polymer particles in drug delivery has remained essentially unchanged for several decades. By taking advantage of the adsorption of protein therapeutics to poly(lactic-co-glycolic acid) (PLGA) nanoparticles, we demonstrate controlled release without encapsulation. In fact, we obtain identical, burst-free, extended-release profiles for three different protein therapeutics with and without encapsulation in PLGA nanoparticles embedded within a hydrogel. Using both positively and negatively charged proteins, we show that short-range electrostatic interactions between the proteins and the PLGA nanoparticles are the underlying mechanism for controlled release. Moreover, we demonstrate tunable release by modifying nanoparticle concentration, nanoparticle size, or environmental pH. These new insights obviate the need for encapsulation and offer promising, translatable strategies for a more effective delivery of therapeutic biomolecules. PMID:27386554
Pakulska, Malgosia M; Elliott Donaghue, Irja; Obermeyer, Jaclyn M; Tuladhar, Anup; McLaughlin, Christopher K; Shendruk, Tyler N; Shoichet, Molly S
Encapsulation of therapeutic molecules within polymer particles is a well-established method for achieving controlled release, yet challenges such as low loading, poor encapsulation efficiency, and loss of protein activity limit clinical translation. Despite this, the paradigm for the use of polymer particles in drug delivery has remained essentially unchanged for several decades. By taking advantage of the adsorption of protein therapeutics to poly(lactic-co-glycolic acid) (PLGA) nanoparticles, we demonstrate controlled release without encapsulation. In fact, we obtain identical, burst-free, extended-release profiles for three different protein therapeutics with and without encapsulation in PLGA nanoparticles embedded within a hydrogel. Using both positively and negatively charged proteins, we show that short-range electrostatic interactions between the proteins and the PLGA nanoparticles are the underlying mechanism for controlled release. Moreover, we demonstrate tunable release by modifying nanoparticle concentration, nanoparticle size, or environmental pH. These new insights obviate the need for encapsulation and offer promising, translatable strategies for a more effective delivery of therapeutic biomolecules.
Cho, Hyunah; Gao, Jieming; Kwon, Glen S
Poly(ethylene glycol)-block-poly(D,L-lactic acid) (PEG-b-PLA) micelles and poly(D,L-lactic-co-glycolic acid)-block-polyethylene glycol)-block-poly(D,L-lactic-co-glycolic acid) (PLGA-b-PEG-b-PLGA) sol-gels have been extensively researched for systemic and localized drug delivery applications, respectively, and they have both progressed into humans for paclitaxel, an important yet poorly water-soluble chemotherapeutic agent. In this review article, preclinical and clinical research on PEG-b-PLA micelles and PLGA-b-PEG-b-PLGA sol-gels that has focused on paclitaxel will be updated, and recent research on other poorly water-soluble anticancer agents and delivery of drug combinations (i.e. multi-drug delivery) that seeks synergistic anticancer efficacy will be summarized. PEG-b-PLA micelles are a first-generation platform for the systemic multi-delivery of poorly water soluble anticancer agents. PLGA-b-PEG-b-PLGA sol-gels are a first-generation platform for the localized multi-drug delivery of water-soluble and/or poorly water-soluble anticancer agents. In summary, PEG-b-PLA micelles and PLGA-b-PEG-b-PLGA sol-gels may safely enable pre-clinical evaluation and clinical translation of poorly water-soluble anticancer agents, especially for promising, rapidly emerging anticancer combinations. Copyright © 2015 Elsevier B.V. All rights reserved.
As obesity and diabetes reach epidemic proportions in the developed world, the role of insulin resistance and its consequences are gaining prominence. Understanding the role of insulin in wide-ranging physiological processes and the influences on its synthesis and secretion, alongside its actions from the molecular to the whole body level, has significant implications for much chronic disease seen in Westernised populations today. This review provides an overview of insulin, its history, structure, synthesis, secretion, actions and interactions followed by a discussion of insulin resistance and its associated clinical manifestations. Specific areas of focus include the actions of insulin and manifestations of insulin resistance in specific organs and tissues, physiological, environmental and pharmacological influences on insulin action and insulin resistance as well as clinical syndromes associated with insulin resistance. Clinical and functional measures of insulin resistance are also covered. Despite our incomplete understanding of the complex biological mechanisms of insulin action and insulin resistance, we need to consider the dramatic social changes of the past century with respect to physical activity, diet, work, socialisation and sleep patterns. Rapid globalisation, urbanisation and industrialisation have spawned epidemics of obesity, diabetes and their attendant co-morbidities, as physical inactivity and dietary imbalance unmask latent predisposing genetic traits. PMID:16278749
Thakur, Chanchal Kiran; Thotakura, Nagarani; Kumar, Rajendra; Kumar, Pramod; Singh, Bhupinder; Chitkara, Deepak; Raza, Kaisar
Breast cancer is believed as the second most common cause of cancer-related deaths in women for which tamoxifen is frequently prescribed. Despite many promises, tamoxifen is associated with various challenges like low hydrophilicity, poor bioavailability and dose-dependent toxicity. Therefore, it was envisioned to develop tamoxifen- loaded chitosan-PLGA micelles for potential safe and better delivery of this promising agent. The chitosan-PLGA copolymer was synthesised and characterised by Fourier Transform-Infrared, Ultraviolet-visible and Nuclear Magnetic Resonance spectroscopic techniques. The drug-loaded nanocarrier was characterised for drug-pay load, micrometrics, surface charge and morphological attributes. The developed system was evaluated for in-vitro drug release, haemolytic profile, cellular-uptake, anticancer activity by cytotoxicity assay and dermatokinetic studies. The developed nano-system was able to substantially load the drug and control the drug release. The in-vitro cytotoxicity offered by the system was significantly enhanced vis-a-vis plain drug, and there was no substantial haemolysis. The IC50 values were significantly decreased and the nanocarriers were uptaken by MCF-7 cells, noticeably. The carrier was able to locate the drug in the interiors of rat skin in considerable amounts to that of the conventional product. This approach is promising as it provides a biocompatible and effective option for better delivery of tamoxifen. Copyright © 2016 Elsevier B.V. All rights reserved.
Zhang, Yifang; Sun, Tingting; Zhang, Fang; Wu, Jian; Fu, Yanyan; Du, Yang; Zhang, Lei; Sun, Ying; Liu, YongHai; Ma, Kai; Liu, Hongzhi; Song, Yuanjian
Magnetic poly (D,L-lactide-co-glycolide) (PLGA)/lipid nanoparticles (MPLs) were fabricated from PLGA, L-α-phosphatidylethanolamine (DOPE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-amino (polyethylene glycol) (DSPE-PEG-NH2), and magnetic nanoparticles (NPs), and then conjugated to trans-activating transcriptor (TAT) peptide. The TAT-MPLs were designed to target the brain by magnetic guidance and TAT conjugation. The drugs hesperidin (HES), naringin (NAR), and glutathione (GSH) were encapsulated in MPLs with drug loading capacity (>10%) and drug encapsulation efficiency (>90%). The therapeutic efficacy of the drug-loaded TAT-MPLs in bEnd.3 cells was compared with that of drug-loaded MPLs. The cells accumulated higher levels of TAT-MPLs than MPLs. In addition, the accumulation of QD-loaded fluorescein isothiocyanate (FITC)-labeled TAT-MPLs in bEnd.3 cells was dose and time dependent. Our results show that TAT-conjugated MPLs may function as an effective drug delivery system that crosses the blood brain barrier to the brain. PMID:25187980
Wen, Xiangru; Wang, Kai; Zhao, Ziming; Zhang, Yifang; Sun, Tingting; Zhang, Fang; Wu, Jian; Fu, Yanyan; Du, Yang; Zhang, Lei; Sun, Ying; Liu, YongHai; Ma, Kai; Liu, Hongzhi; Song, Yuanjian
Magnetic poly (D,L-lactide-co-glycolide) (PLGA)/lipid nanoparticles (MPLs) were fabricated from PLGA, L-α-phosphatidylethanolamine (DOPE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-amino (polyethylene glycol) (DSPE-PEG-NH2), and magnetic nanoparticles (NPs), and then conjugated to trans-activating transcriptor (TAT) peptide. The TAT-MPLs were designed to target the brain by magnetic guidance and TAT conjugation. The drugs hesperidin (HES), naringin (NAR), and glutathione (GSH) were encapsulated in MPLs with drug loading capacity (>10%) and drug encapsulation efficiency (>90%). The therapeutic efficacy of the drug-loaded TAT-MPLs in bEnd.3 cells was compared with that of drug-loaded MPLs. The cells accumulated higher levels of TAT-MPLs than MPLs. In addition, the accumulation of QD-loaded fluorescein isothiocyanate (FITC)-labeled TAT-MPLs in bEnd.3 cells was dose and time dependent. Our results show that TAT-conjugated MPLs may function as an effective drug delivery system that crosses the blood brain barrier to the brain.
Lopes, André M; Chen, Kevin Y; Kamei, Daniel T
We have developed doxorubicin (DOX)-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (DP) conjugated with polyethylene glycol (PEG) and transferrin (Tf) to form Tf-PEG-DPs (TPDPs), and incorporated these TPDPs into three-dimensional (3-D) PLGA porous scaffolds to form a controlled delivery system. To our knowledge, this represents the first use of a Tf variant (oxalate Tf) to improve the targeted delivery of drug-encapsulated nanoparticles (NPs) in PLGA scaffolds to PC3 prostate cancer cells. The PLGA scaffolds with TPDPs incorporated have been shown to release drugs for sustained delivery and provided a continuous release of DOX. The MTS assay was also performed to determine the potency of native and oxalate TPDPs, and a 3.0-fold decrease in IC50 values were observed between the native and oxalate TPDPs. The lower IC50 value for the oxalate version signifies greater potency compared to the native version, since a lower concentration of drug was required to achieve the same therapeutic effect. These results suggest that this technology has potential to become a new implantable polymeric device to improve the controlled and targeted drug delivery of Tf-conjugated NPs for cancer therapy.
Yin, Feng; Cai, Junfeng; Zen, Wen; Wei, Yanhui; Zhou, Wei; Yuan, Feng; Singh, Shree Ram; Wei, Yiyong
Articular cartilage has restricted self-regenerative capacity; therefore, treatment of cartilage lesions is a great challenge in the field of orthopedics. In the present study, we evaluate the enhancing effect of a transforming growth factor-beta 1 (TGF-β1)-immobilized scaffold, fabricated by incorporating TGF-β1-loaded gelatin microspheres into PLGA framework, on the differentiation of adipose-derived stem cells (ASCs) into chondrocytes. Significant increase in cell proliferation was observed in the TGF-β1-immobilized PLGA-gelatin scaffold, as compared with the ASC-seeded non-TGF-β1-immobilized PLGA-gelatin scaffold. When chondrogenic differentiation of ASCs was evaluated for both constructs, sulfated glycosaminoglycan (sGAG) content was significantly higher in the TGF-β1-immobilized scaffold. This study showed that ASCs containing the TGF-β1-immobilized scaffold better promoted cartilage regeneration in defective articular cartilage, which is assessed by histological observation. Based on the above results, we conclude that TGF-β1-immobilized PLGA-gelatin scaffold seeded with ASCs considerably enhances the quality of the tissue-engineered cartilage, therefore, advancing the field of cartilage tissue engineering.
Fornaguera, Cristina; Calderó, Gabriela; Mitjans, Montserrat; Vinardell, Maria Pilar; Solans, Conxita; Vauthier, Christine
The intravenous administration of poly(lactic-co-glycolic) acid (PLGA) nanoparticles has been widely reported as a promising alternative for delivery of drugs to specific cells. However, studies on their interaction with diverse blood components using different techniques are still lacking. Therefore, in the present work, the interaction of PLGA nanoparticles with blood components was described using different complementary techniques. The influence of different encapsulated compounds/functionalizing agents on these interactions was also reported. It is worth noting that all these techniques can be simply performed, without the need for highly sophisticated apparatus or skills. Moreover, their transference to industries and application of quality control could be easily performed. Serum albumin was adsorbed onto all types of tested nanoparticles. The saturation concentration was dependent on the nanoparticle size. In contrast, fibrinogen aggregation was dependent on nanoparticle surface charge. The complement activation was also influenced by the nanoparticle functionalization; the presence of a functionalizing agent increased complement activation, while the addition of an encapsulated compound only caused a slight increase. None of the nanoparticles influenced the coagulation cascade at low concentrations. However, at high concentrations, cationized nanoparticles did activate the coagulation cascade. Interactions of nanoparticles with erythrocytes did not reveal any hemolysis. Interactions of PLGA nanoparticles with blood proteins depended both on the nanoparticle properties and the protein studied. Independent of their loading/surface functionalization, PLGA nanoparticles did not influence the coagulation cascade and did not induce hemolysis of erythrocytes; they could be defined as safe concerning induction of embolization and cell lysis.
Tang, Kevin S.; Hashmi, Sarah M.; Shapiro, Erik M.
Magnetic PLGA nanoparticles are a significant advancement in the quest to translate MRI-based cell tracking to the clinic. The benefits of these types of particles are that they encapsulate large amounts of iron oxide nanocrystals within an FDA-approved polymer matrix, combining the best aspects of inert micron-sized iron oxide particles, or MPIOs, and biodegradable small particles of iron oxide, or SPIOs. Practically, PLGA nanoparticle fabrication and storage requires some form of cryoprotectant to both protect the particle during freeze drying and to promote resuspension. While this is a commonly employed procedure in the fabrication of drug loaded PLGA nanoparticles, it has yet to be investigated for magnetic particles and what effect this might have on internalization of magnetic particles. As such, in this study, magnetic PLGA nanoparticles were fabricated with various concentrations of two common cryoprotectants, dextrose and sucrose, and analyzed for their ability to magnetically label cells. It was found that cryoprotection with either sugar significantly enhanced the ability to resuspend nanoparticles without aggregation. Magnetic cell labeling was impacted by sugar concentration, with higher sugar concentrations used during freeze drying more significantly reducing magnetic cell labeling than lower concentrations. These studies suggest that cryoprotection with 1% dextrose is an optimal compromise that preserves monodispersity following resuspension and high magnetic cell labeling.
Zhou, Lin; Duan, Xingmei; Zeng, Shi; Men, Ke; Zhang, Xueyan; Yang, Li; Li, Xiang
Natural product curcumin (Cur) and H2S-releasing prodrug SH-aspirin (SH-ASA) are potential anticancer agents with diverse mechanisms, but their clinical application prospects are restricted by hydrophobicity and limited efficiency. In this work, we coencapsulated SH-ASA and Cur into methoxy poly(ethylene glycol)-poly (lactide-coglycolide) (mPEG-PLGA) nanoparticles through a modified oil-in-water single-emulsion solvent evaporation process. The prepared SH-ASA/Cur-coloaded mPEG-PLGA nanoparticles had a mean particle size of 122.3±6.8 nm and were monodispersed (polydispersity index =0.179±0.016) in water, with high drug-loading capacity and stability. Intriguingly, by treating with SH-ASA/Cur-coloaded mPEG-PLGA nanoparticles, obvious synergistic anticancer effects on ES-2 and SKOV3 human ovarian carcinoma cells were observed in vitro, and activation of the mitochondrial apoptosis pathway was indicated. Our results demonstrated that SH-ASA/Cur-coloaded mPEG-PLGA nanoparticles could have potential clinical advantages for the treatment of ovarian cancer. PMID:26316750
Li, Zhaojun; Huang, Hui; Huang, Lili; Du, Lianfang; Sun, Ying; Duan, Yourong
In general, atherosclerosis is considered to be a form of chronic inflammation. Dexamethasone has anti-inflammatory effects in atherosclerosis, but it was not considered for long-term administration on account of a poor pharmacokinetic profile and adverse side effects. Nanoparticles in which drugs can be dissolved, encapsulated, entrapped or chemically attached to the particle surface have abilities to incorporate dexamethasone and to be used as controlled or targeted drug delivery system. Long circulatory polymeric nanoparticles present as an assisting approach for controlled and targeted release of the encapsulated drug at the atherosclerotic site. Polymeric nanoparticles combined with ultrasound (US) are widely applied in cancer treatment due to their time applications, low cost, simplicity, and safety. However, there are few studies on atherosclerosis treatment using polymeric nanoparticles combined with US. In this study, targeted dexamethasone acetate (DA)-loaded poly (lactide-glycolide)-polyethylene glycol-cRGD (PLGA-PEG-cRGD) nanoparticles (DA-PLGA-PEG-cRGD NPs) were prepared by the emulsion-evaporation method using cRGD modified PLGA-PEG polymeric materials (PLGA-PEG-cRGD) prepared as the carrier. The average particle size of DA-PLGA-PEG-cRGD NPs was 221.6 ± 0.9 nm. Morphology of the nanoparticles was spherical and uniformly dispersed. In addition, the DA released profiles suggested that ultrasound could promote drug release from the nanocarriers and accelerate the rate of release. In vitro, the cellular uptake process of fluorescein isothiocyanate (FITC)@DA-PLGA-PEG-cRGD NPs combined with US into the damaged human umbilical vein endothelial cells (HUVECs) indicated that US promoted rapid intracellular uptake of FITC@DA- PLGA-PEG-cRGD NPs. The cell viability of DA-PLGA-PEG-cRGD NPs combined with US reached 91.9% ± 0.2%, which demonstrated that DA-PLGA-PEG-cRGD NPs combined with US had a positive therapeutic effect on damaged HUVECs. Overall, DA-PLGA
Adams, G. R.
Adaptations in muscle mass stimulated by changes in muscle loading state entail alternations in the synthesis and degradation of myofiber proteins and the modulation of myonuclear number such that the ratio between the number of myonuclei and the size of the myofibers remains relatively constant. As depicted schematically in Figure 2.6, the literature regarding the role of IGF-in mediating muscle adaptation to alterations in loading state suggests the following conclusions: During periods of increased loading, myofibers upregulate the expression and secretion of IGF-I. Acting as an autocrine and/or paracrine growth factor, IGF-I stimulates myofiber anabolic processes. Acting as a paracrine growth factor, IGF-I also stimulates adjacent satellite cells to enter the cell cycle and proliferate. Continued myofiber production of IGF-I stimulates some satellite cells to differentiate and then fuse with myofibers, thus providing additional myonuclei in order to maintain or reestablish the myonucleus to myofiber size ratios of the enlarged myofibers.
Adams, G. R.
Adaptations in muscle mass stimulated by changes in muscle loading state entail alternations in the synthesis and degradation of myofiber proteins and the modulation of myonuclear number such that the ratio between the number of myonuclei and the size of the myofibers remains relatively constant. As depicted schematically in Figure 2.6, the literature regarding the role of IGF-in mediating muscle adaptation to alterations in loading state suggests the following conclusions: During periods of increased loading, myofibers upregulate the expression and secretion of IGF-I. Acting as an autocrine and/or paracrine growth factor, IGF-I stimulates myofiber anabolic processes. Acting as a paracrine growth factor, IGF-I also stimulates adjacent satellite cells to enter the cell cycle and proliferate. Continued myofiber production of IGF-I stimulates some satellite cells to differentiate and then fuse with myofibers, thus providing additional myonuclei in order to maintain or reestablish the myonucleus to myofiber size ratios of the enlarged myofibers.
Paragkumar N, Thanki; Edith, Dellacherie; Six, Jean-Luc
Surface segregation and restructuring in polylactides (poly( D, L-lactide) and poly( L-lactide)) and poly( D,L-lactide-co-glycolide) (PLGA) films of various thicknesses were investigated using both attenuated total reflection FTIR (ATR-FTIR) and contact angle relaxation measurements. In case of poly( D,L-lactide) (DLPLA), it was observed that the surface segregation and the surface restructuring of methyl side groups are influenced by the polymer film thickness. This result has been confirmed by X-ray photoelectron spectroscopy (XPS). In the same way, PLGA thick films were also characterized by an extensive surface segregation of methyl side groups. Finally, surface restructuring was investigated by dynamic contact angle measurements and it was observed when film surface comes into contact with water. In parallel, we also found that poly( L-lactide) (PLLA) thin and clear films with thickness ˜15 μm undergo conformational changes on the surface upon solvent treatment with certain solvents. The solvent treated surface of PLLA becomes hazy and milky white and its hydrophobicity increases compared to untreated surface. FTIR spectroscopic analysis indicated that polymer chains at the surface undergo certain conformational changes upon solvent treatment. These changes are identified as the restricted motions of C-O-C segments and more intense and specific vibrations of methyl side groups. During solvent treatment, the change in water contact angle and FTIR spectrum of PLLA is well correlated.
Jiang, Tao; Singh, Bijay; Li, Hui-Shan; Kim, You-Kyoung; Kang, Sang-Kee; Nah, Jae-Woon; Choi, Yun-Jaie; Cho, Chong-Su
M cells, the key players of the mucosal immunity induction, are one of the intestinal barriers for the efficient delivery of vaccines to mucosal immune tissues. To overcome the barrier, we have developed an efficient oral vaccine carrier that constitutes poly (lactic-co-glycolic acid) (PLGA) microparticle coated with M cell targeting peptide. In this study, a membrane protein B of Brachyspira hyodysenteriae (BmpB) as a model vaccine against swine dysentery was loaded into porous PLGA microparticles (MPs). The PLGA MPs were further coated with the water-soluble chitosan (WSC) conjugated with M cell homing peptide (CKS9) to prepare BmpB-CKS9-WSC-PLGA MPs. Oral immunization of BmpB vaccine with CKS9-WSC-PLGA MPs in mice showed elevated secretory IgA responses in the mucosal tissues and systemic IgG antibody responses, providing a complete immune response. Specifically, the immunization with these MPs demonstrated to induce both Th1- and Th2-type responses based on elevated IgG1 and IgG2a titers. The elevated immune responses were attributed to the enhanced M cell targeting and transcytosis ability of CKS9-WSC-PLGA MPs to Peyer's patch regions. The high binding affinity of CKS9-WSC-PLGA MPs with the M cells to enter into the Peyer's patch regions of mouse small intestine was investigated by closed ileal loop assay and it was further confirmed by confocal laser scanning microscopy. These results suggest that the M cell targeting approach used in this study is a promising tool for targeted oral vaccine delivery.
Vega, Estefanía; Egea, M Antònia; Garduño-Ramírez, M Luisa; García, M Luisa; Sánchez, Elena; Espina, Marta; Calpena, Ana Cristina
In this study, flurbiprofen (FB) loaded poly(d,l-lactide-co-glycolide) (PLGA) and PLGA with poly(ethylene glycol) (PLGA-PEG) nanospheres (NSs) with and without hydroxypropyl-β-cyclodextrin (HPβCD) were developed as skin controlled delivery systems. X-ray diffraction was used to determine the physical state of the entrapped drug. Results showed that the drug in PLGA NSs was present in the form of a molecular dispersion (dissolved state) in the polymers, whereas in PLGA-PEG NSs, the drug was present in both molecular dispersion and crystalline forms. Furthermore, HPβCD provided solubilization of the free FB present on the surface of the PLGA-PEG NSs and a complete amorphosization of the drug was obtained. Optical analyses using TurbiscanLab(®) demonstrated that HPβCD provided an efficient steric stability of the NSs, preventing particle aggregation. The ex vivo permeation profiles of the NSs and conventional FB solution were evaluated using human skin. Results demonstrated that only PLGA-PEG NSs showed slight permeation improvement. However, after 24h, the FB retained in the skin was about 9-fold higher with NSs compared with the control solution, attributed to the reservoir effect of NSs acting as a depot, sustaining the drug and limiting its systemic absorption. In vivo performance of NSs was evaluated by assessing anti-inflammatory efficacy in TPA-induced mouse ear edema. Topically applied NSs significantly decreased in vivo inflammation compared to the control solution and the anti-inflammatory efficacy of HPβCD NSs was stronger than NSs without HPβCD. In vivo skin irritation evaluated by the in vivo Draize test showed no irritation of the formulations tested. Copyright © 2013 Elsevier B.V. All rights reserved.
Lee, Jae Young; Bashur, Chris A.; Goldstein, Aaron S.; Schmidt, Christine E.
Electrospinning is a promising approach to create nanofiber structures that are capable of supporting adhesion and guiding extension of neurons for nerve regeneration. Concurrently, electrical stimulation of neurons in the absence of topographical features also has been shown to guide axonal extension. Therefore, the goal of this study was to form electrically conductive nanofiber structures and to examine the combined effect of nanofiber structures and electrical stimulation. Conductive meshes were produced by growing polypyrrole (PPy) on random and aligned electrospun poly(lactic-co-glycolic acid) (PLGA) nanofibers, as confirmed by scanning electron micrographs and X-ray photon spectroscopy. PPy-PLGA electrospun meshes supported the growth and differentiation of rat pheochromocytoma 12 (PC12) cells and hippocampal neurons comparable to non-coated PLGA control meshes, suggesting that PPy-PLGA may be suitable as conductive nanofibers for neuronal tissue scaffolds. Electrical stimulation studies showed that PC12 cells, stimulated with a potential of 10 mV/cm on PPy-PLGA scaffolds, exhibited 40–50% longer neurites and 40–90% more neurite formation compared to unstimulated cells on the same scaffolds. In addition, stimulation of the cells on aligned PPy-PLGA fibers resulted in longer neurites and more neurite-bearing cells than stimulation on random PPy-PLGA fibers, suggesting a combined effect of electrical stimulation and topographical guidance and the potential use of these scaffolds for neural tissue applications. PMID:19501901
Prudic, Anke; Lesniak, Anna-Katharina; Ji, Yuanhui; Sadowski, Gabriele
In the current study, the phase behaviour of indomethacin and poly(lactic-co-glycolic acid) (PLGA) formulations was investigated as a function of the molecular weight and the copolymer composition of PLGA. The formulations were prepared by ball milling, and the phase behaviour, comprised of the glass-transition temperature of the formulations and the solubility of indomethacin in PLGA, was measured using modulated differential scanning calorimetry (mDSC). The results determined that the solubility of indomethacin in PLGA at room temperature was very low and increased with a corresponding decrease in the molecular weight of PLGA. The copolymer composition of PLGA had a minor effect on the indomethacin solubility. The effect of PLGA's molecular weight and copolymer composition on the solubility of indomethacin could be modelled using the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) with a high degree of accuracy when compared with the experimental data. The glass-transition temperatures had a negative deviation from the weighted mean of the glass-transition temperatures of the pure substances, which could be described by the Kwei-equation.
la Fleur, S E; Luijendijk, M C M; van Rozen, A J; Kalsbeek, A; Adan, R A H
In diet-induced obesity, it is not clear whether impaired glucose metabolism is caused directly by the diet, or indirectly via obesity. This study examined the effects of different free-choice, high-caloric, obesity-inducing diets on glucose metabolism. In these free-choice diets, saturated fat and/or a 30% sugar solution are provided in an addition to normal chow pellets. In the first experiment, male rats received a free-choice high-fat high-sugar (HFHS), free-choice high-fat (HF) or a chow diet. In a second experiment, male rats received a free-choice high-sugar (HS) diet or chow diet. For both experiments, after weeks 1 and 4, an intravenous glucose tolerance test was performed. Both the HFHS and HF diets resulted in obesity with comparable plasma concentrations of free fatty acids. Interestingly, the HF diet did not affect glucose metabolism, whereas the HFHS diet resulted in hyperglycemia, hyperinsulinemia and in glucose intolerance because of a diminished insulin response. Moreover, adiposity in rats on the HF diet correlated positively with the insulin response to the glucose load, whereas adiposity in rats on the HFHS diet showed a negative correlation. In addition, total caloric intake did not explain differences in glucose tolerance. To test whether sugar itself was crucial, we next performed a similar experiment in rats on the HS diet. Rats consumed three times as much sugar when compared with rats on the HFHS diet, which resulted in obesity with basal hyperinsulinemia. Glucose tolerance, however, was not affected. Together, these results suggest that not only obesity or total caloric intake, but the diet content also is crucial for the glucose intolerance that we observed in rats on the HFHS diet.
Liu, Qi; Ma, Pingchuan; Liu, Lanxia; Ma, Guilei; Ma, Jingjing; Liu, Xiaoxuan; Liu, Yijin; Lin, Wanjun; Zhu, Yingjun
Our study investigated poly(lactic-co-glycolic acid) (PLGA) as protein delivery vehicles encapsulate CTLA-4-antibody (anti-CTLA-4) which is essential for CD4+CD25+Treg cells suppressive function exposing superior potential for inhibiting endometriosis progress in mouse model than single anti-CTLA-4. Anti-CTLA-4 loaded PLGA combined to ligands CTLA-4 in surface of CD4+CD25+Treg cells which distributed in peritoneal fluid of mouse endometriosis model. The particle size, zeta potential of the anti-CTLA-4 loaded nanoparticles was detected by dynamic light scattering. Morphology of nanoparticles was evaluated by transmission electron microscopy (TEM). Confocal laser scanning microscopy (CLSM) indicated distribution of anti-CTLA-4 with PLGA or without in peritoneal fluid. Cumulative anti-CTLA-4 release from nanoparticles was evaluated by Micro BCA assay. The percentage of CD4+CD25+Treg cells in peritoneal fluid was demonstrated by flow cytometer. In vitro experiment we co-culture ectopic endometrial cells (EEC) with isolated CD4+CD25+Treg cells in peritoneal fluid (PF), proliferation and invasion of ectopic endometrial cells (EEC) was measured by BrdU ELISA assay and Matrigel invasion assay. In comparison with anti-CTLA-4 without nanoparticles, the bioconjugates PLGA/anti-CTLA-4 were tolerated in peritoneal fluid with a controlled release of anti-CTLA-4 in 3, 7, 14days. Moreover, PLGA/anti-CTLA-4 had superior protective regulation ability to reduce level of CD4+CD25+Treg cells in peritoneal fluid. Most strikingly, in vitro experiment, PLGA/anti-CTLA-4 exhibited better ability in inhibiting proliferation and invasion of ectopic endometrial cells in co-culture system compared with anti-CTLA-4. Progressively, PLGA/anti-CTLA-4 had better suppressive activity to inhibited IL-10 and TGF-beta secreted by CD4+CD25+Treg cells which indicating that PLGA/anti-CTLA-4 suppressed cells proliferation and invasion through reduced IL-10 and TGF-beta production. Thus, PLGA/anti-CTLA-4 may
Fernández-Carballido, Ana; Puebla, Patricia; Herrero-Vanrell, Rocío; Pastoriza, Pilar
Currently, gamma-irradiation seems to be a good method for sterilising drug delivery systems made from biodegradable polymers. The gamma-irradiation of microspheres can cause several physicochemical changes in the polymeric matrix. These modifications are affected by the temperature, irradiation dose and nature of the encapsulated drug and additives. This study has aimed to evaluate the influence of temperature during the sterilisation process by gamma irradiation in indomethacin PLGA microspheres including a PEG-derivative. Microspheres were prepared by the solvent evaporation method from o/w emulsion and were then exposed to gamma-irradiation. A dose of 25 kGy was used to ensure effective sterilisation. Some microspheres were sterilised with dry ice protection that guaranteed a low temperature during the process whilst others were sterilised without such dry ice protection. The effects of gamma-irradiation on the characteristics of non-loaded PLGA/PEG-derivative and indomethacin loaded PLGA/PEG-derivative microspheres with and without protection were studied. Non-protected microspheres showed changes in their morphological surface, polymer glass transition temperature, molecular weight and release rate of indomethacin after sterilisation. However, microspheres sterilised with protection did not show significant differences after gamma-irradiation exposure. The sterilisation method was satisfactory when the indomethacin loaded microspheres including a PEG-derivative were exposed to gamma-irradiation at low temperature.
... Text Size: A A A Listen En Español Insulin Basics There are different types of insulin depending ... you may be experiencing a reaction. Types of Insulin Rapid-acting insulin , begins to work about 15 ...
... Your Body in Balance › Insulin Secretagogues Fact Sheet Insulin Secretagogues March, 2012 Download PDFs English Espanol Editors ... medicines can help you stay healthy. What are insulin secretagogues? Insulin secretagogues (pronounced seh-KREET-ah-gogs) ...
Wang, Xintong; Venkatraman, Subbu S; Boey, Freddy Y C; Loo, Joachim S C; Tan, Lay Poh
The release of sirolimus from a bi-layer biodegradable polymeric film is reported in this study. Approved drug-eluting metal stents use a thin polymer coating to control drug release, but the degree of control is limited. In a fully polymeric stent, the use of multilayers allows a range of release kinetics. A bi-layer system, with PLLA as the supporting layer and PLGA as the drug-eluting layer, was used in this study to simulate release of sirolimus from a stent. The results show that the release of sirolimus is diffusion and degradation-controlled, and that the amount of sirolimus loading does not affect its release kinetics. The release of sirolimus is, however, accelerated by the addition of a plasticizer, such as PEG, as water uptake is increased. An increased water uptake increases polymer degradation, and changes the dominant mode of release to degradation-control. The release of sirolimus can, on the other hand, be retarded by using a coating of a biodegradable polyester with a lauryl ester end group. Therefore, multilayered systems offer many options for controlling sirolimus release over months.
Puras, G; Salvador, A; Igartua, M; Hernández, R M; Pedraz, J L
The aim of the present work was to develop an easy, safe and effective vaccine in Balb/c mice using the Aβ(1-15) peptide as immunogen entrapped in PLGA microparticles to reduce the risk of an adverse T cell-mediated response. Aβ(1-15,) which contains the N-terminal antibody epitope of the full Aβ(1-42) peptide was encapsulated in PLGA by a modified solvent evaporation/extraction technique using a double emulsion system. Microparticles were characterized in terms of size distribution (1.22±0.28 μm), encapsulation efficiency (75.05±4.17%), surface associated peptide (59.81±0.96%) and "in vitro" release profile. Balb/c mice were immunized by subcutaneous and intranasal routes with three 30 μg doses of the peptide microencapsulated in PLGA. A solution of the peptide alone and an emulsion in the Freund's adjuvant were administered subcutaneously as control groups. Antibody levels elicited against the toxic Aβ(1-40) fraction in the serum of PLGA microparticles treated groups were higher than that of the peptide alone groups. Our initial results indicate that immunotherapy with Aβ(1-15) loaded PLGA microparticles could be a promising approach for the future development of a safe vaccine against Alzheimer's disease. Copyright © 2011 Elsevier B.V. All rights reserved.
Alqahtani, Saeed; Simon, Lacey; Astete, Carlos E; Alayoubi, Alaadin; Sylvester, Paul W; Nazzal, Sami; Shen, Yixiao; Xu, Zhimin; Kaddoumi, Amal; Sabliov, Cristina M
The aim of this study was to formulate and characterize α-tocopherol (α-T) and tocotrienol-rich fraction (TRF) entrapped in poly (lactide-co-glycolide) (PLGA) and chitosan covered PLGA (PLGA-Chi) based nanoparticles. The resultant nanoparticles were characterized and the effect of nanoparticles entrapment on the cellular uptake, antioxidant, and antiproliferative activity of α-T and TRF were tested. In vitro uptake studies in Caco2 cells showed that PLGA and PLGA-Chi nanoparticles displayed a greater enhancement in the cellular uptake of α-T and TRF when compared with the control without causing toxicity to the cells (p<0.0001). Furthermore, the cellular internalization of both PLGA and PLGA-Chi nanoparticles labeled with FITC was investigated by fluorescence microscopy; both types of nanoparticles were able to get internalized into the cells with reasonable amounts. However, PLGA-Chi nanoparticles showed significantly higher (3.5-fold) cellular uptake compared to PLGA nanoparticles. The antioxidant activity studies demonstrated that entrapment of α-T and TRF in PLGA and PLGA-Chi nanoparticles exhibited greater ability in inhibiting cholesterol oxidation at 48 h compared to the control. In vitro antiproliferative studies confirmed marked cytotoxicity of TRF on MCF-7 and MDA-MB-231 cell lines when delivered by PLGA and PLGA-Chi nanoparticles after 48 h incubation compared to control. In summary, PLGA and PLGA-Chi nanoparticles may be considered as an attractive and promising approach to enhance the bioavailability and activity of poorly water soluble compounds such as α-tocopherol and tocotrienols.
Background Combination antiretroviral (AR) therapy continues to be the mainstay for HIV treatment. However, antiretroviral drug nonadherence can lead to the development of resistance and treatment failure. We have designed nanoparticles (NP) that contain three AR drugs and characterized the size, shape, and surface charge. Additionally, we investigated the in vitro release of the AR drugs from the NP using peripheral blood mononuclear cells (PBMCs). Methods Poly-(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) containing ritonavir (RTV), lopinavir (LPV), and efavirenz (EFV) were fabricated using multiple emulsion-solvent evaporation procedure. The nanoparticles were characterized by electron microscopy and zeta potential for size, shape, and charge. The intracellular concentration of AR drugs was determined over 28 days from NPs incubated with PBMCs. Macrophages were imaged by fluorescent microscopy and flow cytometry after incubation with fluorescent NPs. Finally, macrophage cytotoxicity was determined by MTT assay. Results Nanoparticle size averaged 262 ± 83.9 nm and zeta potential -11.4 ± 2.4. AR loading averaged 4% (w/v). Antiretroviral drug levels were determined in PBMCs after 100 μg of NP in 75 μL PBS was added to media. Intracellular peak AR levels from NPs (day 4) were RTV 2.5 ± 1.1; LPV 4.1 ± 2.0; and EFV 10.6 ± 2.7 μg and continued until day 28 (all AR ≥ 0.9 μg). Free drugs (25 μg of each drug in 25 μL ethanol) added to PBMCs served as control were eliminated by 2 days. Fluorescence microscopy and flow cytometry demonstrated phagocytosis of NP into monocytes-derived macrophages (MDMs). Cellular MTT assay performed on MDMs demonstrated that NPs are not significantly cytotoxic. Conclusion These results demonstrated AR NPs could be fabricated containing three antiretroviral drugs (RTV, LPV, EFV). Sustained release of AR from PLGA NP show high drug levels in PBMCs until day 28 without cytotoxicity. PMID:20003214
S, Saravanan; S, Malathi; P S L, Sesh; S, Selvasubramanian; S, Balasubramanian; V, Pandiyan
The aim of the present study is to evaluate the effect of insulin loaded poly(ethylene glycol) capped poly(lactic-co-glycolic)acid nanoparticles (ISPPLG NPs) by subcutaneous administration in diabetic rats. A series of biodegradable low molecular weight PLGA [90/10 (PLG2) and 80/20 (PLG4)] copolymers were synthesized by melt polycondensation and their ISPPLG NPs were synthesized by water-oil-water (W/O/W) emulsion solvent evaporation method. The PLGA copolymers and their nanoparticles were characterized. The maximum encapsulation efficiency of ISPPLG4 NPs is 66% and the diameter of the nanoparticles is about 140nm. The in-vivo studies of ISPPLG NPs carried out in diabetic rats by subcutaneous administration show considerable reduction in serum glucose level along with partial restoration of tissue defense systems. Histopathological studies reveal that ISPPLG NPs could restore the damages caused by oxidants during hyperglycaemia. The subcutaneous administration of ISPPLG4 NPs is thus an effective method of reducing hyperglycaemia associated complications.
Hiremath, Jagadish; Kang, Kyung-il; Xia, Ming; Elaish, Mohamed; Binjawadagi, Basavaraj; Ouyang, Kang; Dhakal, Santosh; Arcos, Jesus; Torrelles, Jordi B.; Jiang, X.; Lee, Chang Won; Renukaradhya, Gourapura J.
Pigs are believed to be one of the important sources of emerging human and swine influenza viruses (SwIV). Influenza virus conserved peptides have the potential to elicit cross-protective immune response, but without the help of potent adjuvant and delivery system they are poorly immunogenic. Biodegradable polylactic-co-glycolic acid (PLGA) nanoparticle (PLGA-NP) based vaccine delivery system enhances cross-presentation of antigens by the professional antigen presenting cells. In this study, Norovirus P particle containing SwIV M2e (extracellular domain of the matrix protein 2) chimera and highly conserved two each of H1N1 peptides of pandemic 2009 and classical human influenza viruses were entrapped in PLGA-NPs. Influenza antibody-free pigs were vaccinated with PLGA-NPs peptides cocktail vaccine twice with or without an adjuvant, Mycobacterium vaccae whole cell lysate, intranasally as mist. Vaccinated pigs were challenged with a virulent heterologous zoonotic SwIV H1N1, and one week later euthanized and the lung samples were analyzed for the specific immune response and viral load. Clinically, pigs vaccinated with PLGA-NP peptides vaccine had no fever and flu symptoms, and the replicating challenged SwIV was undetectable in the bronchoalveolar lavage fluid. Immunologically, PLGA-NP peptides vaccination (without adjuvant) significantly increased the frequency of antigen-specific IFNγ secreting CD4 and CD8 T cells response in the lung lymphocytes, despite not boosting the antibody response both at pre- and post-challenge. In summary, our data indicated that nanoparticle-mediated delivery of conserved H1N1 influenza peptides induced the virus specific T cell response in the lungs and reduced the challenged heterologous virus load in the airways of pigs. PMID:27093541
Shen, Xue; Li, Tingting; Chen, Zhongyuan; Geng, Yue; Xie, Xiaoxue; Li, Shun; Yang, Hong; Wu, Chunhui; Liu, Yiyao
Cancer diagnosis and treatment represent an urgent medical need given the rising cancer incidence over the past few decades. Cancer theranostics, namely, the combination of diagnostics and therapeutics within a single agent, are being developed using various anticancer drug-, siRNA-, or inorganic materials-loaded nanocarriers. Herein, we demonstrate a strategy of encapsulating quantum dots, superparamagnetic Fe3O4 nanocrystals, and doxorubicin (DOX) into biodegradable poly(d,l-lactic-co-glycolic acid) (PLGA) polymeric nanocomposites using the double emulsion solvent evaporation method, followed by coupling to the amine group of polyethyleneimine premodified with polyethylene glycol-folic acid (PEI-PEG-FA [PPF]) segments and adsorption of vascular endothelial growth factor (VEGF)-targeted small hairpin RNA (shRNA). VEGF is important for tumor growth, progression, and metastasis. These drug-loaded luminescent/magnetic PLGA-based hybrid nanocomposites (LDM-PLGA/PPF/VEGF shRNA) were fabricated for tumor-specific targeting, drug/gene delivery, and cancer imaging. The data showed that LDM-PLGA/PPF/VEGF shRNA nanocomposites can codeliver DOX and VEGF shRNA into tumor cells and effectively suppress VEGF expression, exhibiting remarkable synergistic antitumor effects both in vitro and in vivo. The cell viability waŝ14% when treated with LDM-PLGA/PPF/VEGF shRNA nanocomposites ([DOX] =25 μg/mL), and in vivo tumor growth data showed that the tumor volume decreased by 81% compared with the saline group at 21 days postinjection. Magnetic resonance and fluorescence imaging data revealed that the luminescent/magnetic hybrid nanocomposites may also be used as an efficient nanoprobe for enhanced T2-weighted magnetic resonance and fluorescence imaging in vitro and in vivo. The present work validates the great potential of the developed multifunctional LDM-PLGA/PPF/VEGF shRNA nanocomposites as effective theranostic agents through the codelivery of drugs/genes and dual
Hiremath, Jagadish; Kang, Kyung-il; Xia, Ming; Elaish, Mohamed; Binjawadagi, Basavaraj; Ouyang, Kang; Dhakal, Santosh; Arcos, Jesus; Torrelles, Jordi B; Jiang, X; Lee, Chang Won; Renukaradhya, Gourapura J
Pigs are believed to be one of the important sources of emerging human and swine influenza viruses (SwIV). Influenza virus conserved peptides have the potential to elicit cross-protective immune response, but without the help of potent adjuvant and delivery system they are poorly immunogenic. Biodegradable polylactic-co-glycolic acid (PLGA) nanoparticle (PLGA-NP) based vaccine delivery system enhances cross-presentation of antigens by the professional antigen presenting cells. In this study, Norovirus P particle containing SwIV M2e (extracellular domain of the matrix protein 2) chimera and highly conserved two each of H1N1 peptides of pandemic 2009 and classical human influenza viruses were entrapped in PLGA-NPs. Influenza antibody-free pigs were vaccinated with PLGA-NPs peptides cocktail vaccine twice with or without an adjuvant, Mycobacterium vaccae whole cell lysate, intranasally as mist. Vaccinated pigs were challenged with a virulent heterologous zoonotic SwIV H1N1, and one week later euthanized and the lung samples were analyzed for the specific immune response and viral load. Clinically, pigs vaccinated with PLGA-NP peptides vaccine had no fever and flu symptoms, and the replicating challenged SwIV was undetectable in the bronchoalveolar lavage fluid. Immunologically, PLGA-NP peptides vaccination (without adjuvant) significantly increased the frequency of antigen-specific IFNγ secreting CD4 and CD8 T cells response in the lung lymphocytes, despite not boosting the antibody response both at pre- and post-challenge. In summary, our data indicated that nanoparticle-mediated delivery of conserved H1N1 influenza peptides induced the virus specific T cell response in the lungs and reduced the challenged heterologous virus load in the airways of pigs.
Gorjikhah, Fatemeh; Azizi Jalalian, Farid; Salehi, Roya; Panahi, Yunes; Hasanzadeh, Arash; Alizadeh, Effat; Akbarzadeh, Abolfazl; Davaran, Soodabeh
Among all cancers that affect women, breast cancer has most mortality rate. It is essential to attain more safe and efficient anticancer drugs. Recent advances in medical nanotechnology and biotechnology have caused in novel improvements in breast and other cancer drug delivery. Methotrexate is an anticancer drug that prevents the dihydrofolate reductase enzyme, which inhibits in the formation of DNA, RNA and proteins which have poor water-solubility. For enhancing the solubility and stability of drugs in delivery systems, we used methotrexate-loaded PLGA- beta-cyclodextrin nanoparticles. The PLGA- beta-cyclodextrin nanoparticles were synthesized by a double emulsion method and characterized with FT-IR and SEM. T47D breast cancer cell lines were treated with equal concentrations of methotrexate-loaded PLGA- beta-cyclodextrin nanoparticles and free methotrexate. MTT assay confirmed that methotrexate-loaded PLGA- beta-cyclodextrin nanoparticles enhanced cytotoxicity and drug delivery in T47D breast cancer cells. These results indicate that encapsulated drugs could be effective in controlled drug release for a sustained period would serve the purpose for long-term treatment of many diseases such as breast cancer.
Particle size is a key feature in determining performance of nanoparticles as drug carriers because it influences circulating half-life, cellular uptake and biodistribution. Because the size of particles has such a major impact on their performance, the uniformity of the particle population is also a significant factor. Particles comprised of the polymer poly(lactic-co-glycolic acid) (PLGA) are widely studied as therapeutic delivery vehicles because they are biodegradable and biocompatible. In fact, microparticles comprised of PLGA are already approved for drug delivery. Unfortunately, PLGA nanoparticles prepared by conventional methods usually lack uniformity. We developed a novel Fluidic NanoPrecipitation System (FNPS) to fabricate highly uniform PLGA particles. Several parameters can be fine-tuned to generate particles of various sizes. PMID:20707919
Tang, Xiaolong; Jiao, Ronghong; Xie, Chunmei; Xu, Lifa; Huo, Zhen; Dai, Jingjing; Qian, Yunyun; Xu, Weiwen; Hou, Wei; Wang, Jiang; Liang, Yong
To develop amphotericin B-loaded biodegradable TPGS-b-(PCL-ran-PGA) nanoparticles (PLGA-TPGS-AMB NPs) for fungal infection treatment, PLGA-TPGS NPs and PLGA NPs were synthesized by a modified double emulsion method and characterized in terms of size and size distribution, morphology and zeta potential. Drug encapsulation efficiency, in vitro drug release, and in vitro/vivo tests against Candida glabrata were completed. The data showed that both of the two AMB-loaded NPs (PLGA-AMB NPs, PLGA-TPGS-AMB NPs) achieved significantly higher level of antifungal effects than water suspended AMB. In comparison with PLGA-AMB NPs, PLGA-TPGS-AMB NPs had a stronger protective effect against candidiasis and gained an advantage of prolonged antifungal efficacy. In conclusion, PLGA-TPGS-AMB NPs system significantly improves AMB bioavailability by increasing the aqueous dispersibility and improving the antifungal activity. And this would be an excellent choice for the antifungal treatment of the entrapped drug because of its low toxicity and higher effectiveness. PMID:26131089
Cai, Qiang; Wang, Long; Deng, Gang; Liu, Junhui; Chen, Qianxue; Chen, Zhibiao
Neurological disorders are an important global public health problem, but pharmaceutical treatments are limited due to drug access to the central nervous system being restricted by the blood-brain barrier (BBB). Poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) are one of the most promising drug and gene delivery systems for crossing the BBB. While these systems offer great promise, PLGA NPs also have some intrinsic drawbacks and require further engineering for clinical and research applications. Multiple strategies have been developed for using PLGA NPs to deliver compounds across the BBB. We classify these strategies into three categories according to the adaptations made to the PLGA NPs (1) to facilitate travel from the injection site (pre-transcytosis strategies); (2) to enhance passage across the brain endothelial cells (BBB transcytosis strategies) and (3) to achieve targeting of the impaired nervous system cells (post-transcytosis strategies). PLGA NPs modified according to these three strategies are denoted first, second, and third generation NPs, respectively. We believe that fusing these three strategies to engineer multifunctional PLGA NPs is the only way to achieve translational applications. PMID:27158367
Pascolo, Lorella; Bortot, Barbara; Benseny-Cases, Nuria; Gianoncelli, Alessandra; Tosi, Giovanni; Ruozi, Barbara; Rizzardi, Clara; De Martino, Eleonora; Vandelli, Maria Angela; Severini, Giovanni Maria
Poly-lactide-co-glycolide (PLGA) is one of the few polymers approved by the US Food and Drug Administration as a carrier for drug administration in humans; therefore, it is one of the most used materials in the formulation of polymeric nanoparticles (NPs) for therapeutic purposes. Because the cellular uptake of polymeric NPs is a hot topic in the nanomedicine field, the development of techniques able to ensure incontrovertible evidence of the presence of NPs in the cells plays a key role in gaining understanding of their therapeutic potential. On the strength of this premise, this article aims to evaluate the application of synchrotron radiation-based Fourier transform infrared spectroscopy (SR-FTIR) spectromicroscopy and SR X-ray fluorescence (SR-XRF) microscopy in the study of the in vitro interaction of PLGA NPs with cells. To reach this goal, we used PLGA NPs, sized around 200 nm and loaded with superparamagnetic iron oxide NPs (PLGA-IO-NPs; Fe₃O₄; size, 10-15 nm). After exposing human mesothelial (MeT5A) cells to PLGA-IO-NPs (0.1 mg/mL), the cells were analyzed after fixation both by SR-FTIR spectromicroscopy and SR-XRF microscopy setups. SR-FTIR-SM enabled the detection of PLGA NPs at single-cell level, allowing polymer detection inside the biological matrix by the characteristic band in the 1,700-2,000 cm(-1) region. The precise PLGA IR-signature (1,750 cm(-1) centered pick) also was clearly evident within an area of high amide density. SR-XRF microscopy performed on the same cells investigated under SR-FTIR microscopy allowed us to put in evidence the Fe presence in the cells and to emphasize the intracellular localization of the PLGA-IO-NPs. These findings suggest that SR-FTIR and SR-XRF techniques could be two valuable tools to follow the PLGA NPs' fate in in vitro studies on cell cultures.
Pascolo, Lorella; Bortot, Barbara; Benseny-Cases, Nuria; Gianoncelli, Alessandra; Tosi, Giovanni; Ruozi, Barbara; Rizzardi, Clara; De Martino, Eleonora; Vandelli, Maria Angela; Severini, Giovanni Maria
Poly-lactide-co-glycolide (PLGA) is one of the few polymers approved by the US Food and Drug Administration as a carrier for drug administration in humans; therefore, it is one of the most used materials in the formulation of polymeric nanoparticles (NPs) for therapeutic purposes. Because the cellular uptake of polymeric NPs is a hot topic in the nanomedicine field, the development of techniques able to ensure incontrovertible evidence of the presence of NPs in the cells plays a key role in gaining understanding of their therapeutic potential. On the strength of this premise, this article aims to evaluate the application of synchrotron radiation-based Fourier transform infrared spectroscopy (SR-FTIR) spectromicroscopy and SR X-ray fluorescence (SR-XRF) microscopy in the study of the in vitro interaction of PLGA NPs with cells. To reach this goal, we used PLGA NPs, sized around 200 nm and loaded with superparamagnetic iron oxide NPs (PLGA-IO-NPs; Fe3O4; size, 10–15 nm). After exposing human mesothelial (MeT5A) cells to PLGA-IO-NPs (0.1 mg/mL), the cells were analyzed after fixation both by SR-FTIR spectromicroscopy and SR-XRF microscopy setups. SR-FTIR-SM enabled the detection of PLGA NPs at single-cell level, allowing polymer detection inside the biological matrix by the characteristic band in the 1,700–2,000 cm−1 region. The precise PLGA IR-signature (1,750 cm−1 centered pick) also was clearly evident within an area of high amide density. SR-XRF microscopy performed on the same cells investigated under SR-FTIR microscopy allowed us to put in evidence the Fe presence in the cells and to emphasize the intracellular localization of the PLGA-IO-NPs. These findings suggest that SR-FTIR and SR-XRF techniques could be two valuable tools to follow the PLGA NPs’ fate in in vitro studies on cell cultures. PMID:24944512
Su, Yongsheng; Hu, Jian; Huang, Zhibin; Huang, Yubin; Peng, Bingsheng; Xie, Ni; Liu, Hui
Malignant melanoma (MM) is the most dangerous type of skin cancer with annually increasing incidence and death rates. However, chemotherapy for MM is restricted by low topical drug concentration and multidrug resistance. In order to surmount the limitation and to enhance the therapeutic effect on MM, a new nanoformulation of paclitaxel (PTX)-loaded cholic acid (CA)-functionalized star-shaped poly(lactide-co-glycolide) (PLGA)-D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) nanoparticles (NPs) (shortly PTX-loaded CA-PLGA-TPGS NPs) was fabricated by a modified method of nanoprecipitation. The particle size, zeta potential, morphology, drug release profile, drug encapsulation efficiency, and loading content of PTX-loaded NPs were detected. As shown by confocal laser scanning, NPs loaded with coumarin-6 were internalized by human melanoma cell line A875. The cellular uptake efficiency of CA-PLGA-TPGS NPs was higher than those of PLGA NPs and PLGA-TPGS NPs. The antitumor effects of PTX-loaded NPs were evaluated by the MTT assay in vitro and by a xenograft tumor model in vivo, demonstrating that star-shaped PTX-loaded CA-PLGA-TPGS NPs were significantly superior to commercial PTX formulation Taxol®. Such drug delivery nanocarriers are potentially applicable to the improvement of clinical MM therapy. PMID:28293102
Su, Yongsheng; Hu, Jian; Huang, Zhibin; Huang, Yubin; Peng, Bingsheng; Xie, Ni; Liu, Hui
Malignant melanoma (MM) is the most dangerous type of skin cancer with annually increasing incidence and death rates. However, chemotherapy for MM is restricted by low topical drug concentration and multidrug resistance. In order to surmount the limitation and to enhance the therapeutic effect on MM, a new nanoformulation of paclitaxel (PTX)-loaded cholic acid (CA)-functionalized star-shaped poly(lactide-co-glycolide) (PLGA)-D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) nanoparticles (NPs) (shortly PTX-loaded CA-PLGA-TPGS NPs) was fabricated by a modified method of nanoprecipitation. The particle size, zeta potential, morphology, drug release profile, drug encapsulation efficiency, and loading content of PTX-loaded NPs were detected. As shown by confocal laser scanning, NPs loaded with coumarin-6 were internalized by human melanoma cell line A875. The cellular uptake efficiency of CA-PLGA-TPGS NPs was higher than those of PLGA NPs and PLGA-TPGS NPs. The antitumor effects of PTX-loaded NPs were evaluated by the MTT assay in vitro and by a xenograft tumor model in vivo, demonstrating that star-shaped PTX-loaded CA-PLGA-TPGS NPs were significantly superior to commercial PTX formulation Taxol(®). Such drug delivery nanocarriers are potentially applicable to the improvement of clinical MM therapy.
Patel, Roshni S; Cho, Daniel Y; Tian, Cheng; Chang, Amy; Estrellas, Kenneth M; Lavin, Danya; Furtado, Stacia; Mathiowitz, Edith
We report on the development of a modified solvent removal method for the encapsulation of hydrophilic drugs within poly(lactic-co-glycolic acid) (PLGA). Using a water/oil/oil double emulsion, hydrophilic doxycycline was encapsulated within PLGA spheres with particle diameters ranging from approximately 600 nm to 19 µm. Encapsulation efficiencies of up to 74% were achieved for theoretical loadings from 1% to 10% (w/w), with biphasic release over 85 days with nearly complete release at the end of this time course. About 1% salt was added to the formulations to examine its effects on doxycycline release; salt m