Starting from lower molecular weight poly(D,L-lactic acid)(PDLLA) produced by direct melt polycondensation of D,L-lactic acid(D,L-LA),poly(lactic acid) drug delivery material was synthesized through diisocyanate chain extension.

• 以外消旋乳酸(D,L-LA)直接熔融聚合得到的低相对分子质量聚外消旋乳酸(PDLLA)为原料,通过二异氰酸酯扩链合成了聚乳酸类药物缓释材料。