A medical polymer device comprising a biodegradable polymer is provided, wherein the biodegradable polymer has a crystallinity of about 10% to about 80%, and preferably from about 20% to about 60%, wherein the medical polymer device comprises a small molecule organic compound which diffuses into the biodegradable polymer, the small molecule organic compound has a molecular weight of from about 100 to about 1000 Daltons, preferably from about 150 to about 500 Daltons, and more preferably from about 150 to about 250 Daltons, and the small molecule organic compound is non-evaporating or low-evaporating. The present invention also provides a method for preparing a medical polymer device according to the present invention as well as a method for modifying a medical polymer device made from a biodegradable polymer.