Dextran-poly lactide-co-glycolide polymersomes decorated with folate-antennae for targeted delivery of docetaxel to breast adenocarcinima in vitro and in vivo.

In this study, a tumor-targeted, docetaxel encapsulated dextran-poly lactide-co-glycolide (DEX-PLGA) polymersomes was fabricated for breast cancer chemotherapy. To attain active cancer targeting, docetaxel encapsulated polymersomes was conjugated with folate for folate receptor guided delivery which is overexpressed in various cancer cells including breast adenocarcinoma. Docetaxel was encapsulated in the bilayer of DEX-PLGA or folate-conjugated DEX-PLGA (FA-DEX-PLGA) polymersomes via nanoprecipitation method in order to provide the controlled drug release. The size of polymersomes obtained were 178.53±2.5nm and offered drug encapsulation efficiency and loading content of 78.85±3.81% and 9.32±0.27, respectively. The data demonstrate that the prepared polymersome formulations sustained docetaxel release for a period of 6days. Cellular uptake study and MTT assay showed that the developed folate-targeted docetaxel-loaded polymersomes had higher cytotoxicity than non-targeted ones as well as free form of drug and was accumulated in 4T1 and MCF-7 cells in vitro. The in vivo tumor inhibitory effect of folate-conjugated docetaxel-loaded DEX-PLGA polymersomes (FA-DEX-PLGA-DTX-NPs) demonstrated an increased therapeutic potency of targeted formulation over both non-targeted (DEX-PLGA-DTX-NPs) and free drug. The represented data reveal that the prepared targeted drug delivery system was able to control the docetaxel release, and also enhance the antitumor potency of docetaxel. This study may open new direction for preparation of folate receptor targeted polymersomes based on DEX-PLGA copolymers for translational purposes.

Dextran-b-poly(lactide-co-glycolide) polymersome for oral delivery of insulin: In vitro and in vivo evaluation.

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.