Enzymatic degradations of copolymers of L-lactide with cyclic carbonates

Syntheses and biodegradation of random copolymers of L-lactide (L-LA) with trimethylene carbonate (TMC), 1,1-dimenthyltrimethylene carbonate (1,1-DTMC) and 2,2-dimethyltrimethylene carbonate (2,2-DTMC) were investigated at various monomer ratios using SmMe-(C 5 Me 5 ) 2 THF as an initiator at 80°C for 24 h in toluene. Enzymatic degradation of these polymers were performed using cholesterol esterase, lipoprotein lipase, and proteinase K. Poly(TMC) was effectively biodegraded by cholesterol esterase and lipoprotein lipase, while poly(2,2-DTMC) and all the copolymers were hardly degraded using these enzymes. Biodegradations of poly(L-LA-co-TMC) (97:3) and poly(L-LA-co-2,2,DTMC) (95.5) show rapid degradations using TES buffer, a compost and proteinase K. The physical properties of these copolymers were also examined.