Synthesis and properties of poly(L-lactide)-poly(ethylene glycol) multiblock copolymers

A series of multiblock copolymers of PLLA-PEG(PLE) with high molecular weight were synthesized by coupling PLLA-PEG-PLLA triblock copolymers with succinic anhydride in the presence of (N,N-dimethylamino) pyridine(DMAP) and dicyclohexylcarbodimide (DCC). The results of the viscometry measurement, GPC and H-1-MR, elucidated that multiblock PLE copolymers with high content of short PEG segments (Mn= 2000) had been successfully obtained. The crystallinity of the copolymers was investigated by X-ray diffraction. Mechanical testing showed that multiblock copolymers had relatively high tensile strength and large elongation. In a word, the measurements showed that the multiblock PLE copolymers had high content of short PEG segments (M-n = 2000), high molecular weight (M-w similar to 100,000), excellent hydrophilicity and mechanical properties. The results of cells cultured on the multiblock PLE copolymer indicated that it might be suitable to be utilized as cell scaffold for tissue engineering.