[Research progresses on degradation mechanism in vivo and medical applications of polylactic acid].

Polylactic acid (PLA), a kind of aliphatic polyester, is a biodegradable polymer with outstanding biocompatibility. The degradation of PLA is a complex process involving four main phenomena, namely water absorption, ester cleavage, diffusion of soluble oligomers, and solubilization of fragments. This paper emphasizes on the following aspects: 1) present understanding of the hydrolytic degradation and enzymatic degradation of PLA and autocatalystic degradation mechanism in the bulk PLA; 2) main factors influencing PLA degradation; 3) biological results; 4) the development in application of PLA.