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Date of Publication:2006-01-01

Journal:功能材料

Issue:2

Page Number:277-280

ISSN No.:1001-9731

Abstract:In order to avoid the restenosis after percutaneous transluminal coronary angioplasty (PTCA), the drug-loaded polymer coating is prepared on the surface of stents to prevent proliferation of smooth muscle cell. In this work, we use degradable polymer named PLGA as the coating of stents, and place the PLGA membrane into the in-vitro circulation device in pH7.4 Hank's simulation body's liquid at 37°C to simulate the in-vivo degradation under the blood washing influence. To evaluate the effect of flowing to the degradation of PLGA, both the dynamic and static degradation were performed. The changes of molecular weight, molecular weight distribution (polydispersity), loss weight, composition of the polymer and thermal properties were determined by SEM, GPC, 1H-NMR and DSC techniques, furthermore the dynamic and static degradation mechanism is discussed. The results show that in flowing solution, the changes of morphology, weight and molecular weight were more slowly compared with static degradation. That attributes to the micro-circumstance on polymer surface.

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