Conclusion
In conclusion copolymers of PEG/PLA with f OE ~25% and relatively higher molecular weight are more suitable for encapsulation and providing sustained release of DOX.
Discussion
Results obtained from (1)HNMR and GPC revealed that microwave irradiation is a simple and reliable method for the synthesis of PEG-PLA copolymers. Further analysis indicated the copolymer with relative molecular weight of PLA to PEG ratios of 3 or f Eo ~ 25% produced the smallest size polymersomes. Polymersomes prepared from PEG5000 to PLA15000 were more capable in loading and sustained release of DOX than those prepared from PEG2000 to PLA6000. Conclusion: In conclusion copolymers of PEG/PLA with f OE ~25% and relatively higher molecular weight are more suitable for encapsulation and providing sustained release of DOX.
Methods
Herein, a series of poly (lactic acid) (PLA) and PEG diblock copolymers were synthesized through the ring-opening polymerization. The polymerization reaction and the copolymer structures were evaluated by nuclear magnetic resonance (NMR) and gel permeation chromatography (GPC). The corresponding copolymers were implemented for the formation of polymersome structures using film rehydration method. Impact of methoxy PEG chain length and hydrophobic weight fraction on particle size of polymersomes were studied, and the proper ones were selected for loading of doxorubicin (DOX) via pH gradient method.