Study on synthesis and application of collagen‐modified polylactic acid

To modify the degradability and improve the hydrophilicity of polylactic acid (PLA), collagen‐modified polylactide (CPLA) was synthesized by means of grafting modification method including chloridization and aminolysis, and its structure was characterized by FTIR, 1 H NMR, and fluorescein isothiocyanate‐labeled fluorescence spectra. Subsequently, the hydrophilicity and degradation behavior of CPLA were characterized. Finally, CPLA was used as a carrier for the preparation of the trypsin sustained release microspheres via the emulsion‐solvent evaporation technique, followed with its characterization. Results showed that the collagen had been grafted into PLA and the graft ratio of collagen measured about 6.7%. Water absorption behavior test indicated that the hydrophilicity of CPLA was significantly higher than PLA. Furthermore, degradability test revealed that the degradation behavior of PLA was obviously modified and there was no obvious acid‐catalyzed self‐accelerating degradation behavior in the degradation process of CPLA. It was also indicated that the encapsulation efficiency and drug content in trypsin‐loaded CPLA microspheres were all clearly higher than trypsin‐loaded PLA microspheres. The results suggested that CPLA showed a great potential as matrix for drug delivery. POLYM. COMPOS., 36:88–93, 2015. © 2014 Society of Plastics Engineers