Biodegradable polyesters

such as PLA and PLGA

have proven to be very useful protein delivery sustained release vehicle material and can provide prolonged protein release thanks to their good biocompatibility and biodegradability. This review provides an applicable summary of different formulation routes to forming polyesters and their derivatives for the purpose of (1) improving the hydrophilic property of PLGA through introducing molecule having ether bond

such as PEO

PEG

in PLGA and forming PLGA block copolymer; (2) enhancing the adhesion of vehicle and cell by immobilizing the cell-recognizable ligand moiety and/or peptide onto the surface of biodegradable polymer scaffolds and achieving targeted PLGA derivatives; and (3) developing novel branched polyesters PVA-g- PLGA and obtaining zero-order drug release kinetics through changing the acid microclimate in PLGA vehicle and improving the stability of protein inner the vehicle. All of the above PLGA and their derivatives can produce safe

qualified and efficacious vehicle for protein and peptide drug delivery system.