PLLA-PEG-PLLA Copolymer Synthsis And Study On Their Microspheres Preparation And Properties

As the development of medical and pharmaceutical technology, the traditional ways of drug delivery can not meet the complex and up-to-date requirements. Thus the advanced ways of drug delivery become the focus of medical and pharmaceutical fields. Drug-loaded microsphere is one of the most important way of drug delivery. Not only can it realize the controlled release of drugs, but also the targeted delivery and smart delivery can be easily achieved by using microspheres.PLA/PEG block copolymers have ideal biocompatibility and biodegradability. The properties of PLA/PEG block copolymers, such as the hydrophobicity and hydrophilicity, the crystallbility and the degradability, can be easily adjusted by varying the block structure of the copolymers. Thus the PLA/PEG block copolymers can meet different needs of drug delivery. So, PLA/PEG become an ideal materials of drug delivery carriers and are finding more widely application.In this study, we synthesized a series of PLA-PEG-PLA triblock copolymers and prepared microspheres of these copolymers by using doubleemulsion method. We employed a hydrophilic, macromolecular drug-heparin as the model drug and investigated the influence of block structure and emulsifier type on the encapsulation efficiency, surface morphology and in vitro...