可完全生物降解材料聚乳酸-聚羟基乙酸复合壳聚糖在人工心血管支架制备中的应用

裸金属支架（bare metal stents，BMS）和涂层支架（drug eluting stents，DES）介入治疗冠心病已在临床广泛应用，但由于金属支架的异物刺激或携带药物的干扰容易引起支架内再狭窄和血管栓塞，由聚酯、聚碳酸酐及聚磷酸酯等高分子材料制备的完全可生物降解吸收支架及药物洗脱支架应运而生。目前由共聚物材料制备的人工心血管植入支架的安全性、组织及血液相容性已得到证实，然而这些支架具有各自的问题，如降解的速度、材料的柔韧度、硬度以及支撑力不均一等，尚不能满足实际应用的要求。本文就聚乳酸（polylactic acid，PLA）、聚羟基乙酸（polyglycolic acid，PGA）和壳聚糖在人工冠脉血管支架制备中的应用现状及研发方向予以综述。

Artificial Coronary Vascular Stents Fabrication Using the Biodegradable Material Compounds: PLA-PGA-co-Chitosan

The first two generation scaffolds： bare metal stents （BMS） and drug eluting stents （DES） , have been widely used in the treatment of coronary heart diseases. However, long term incidences of major adverse cardiovascular events and revascularization treatments are still high because of in-stent re-stenosis and thrombosis. These may be caused by chronic inflammations and vascular wall damages due to persistent metal stents stimulation. The eluting drugs within metal stents could also disturb normal growth of vascular endothelial cell, intima, tuniea media, smooth muscle and epimysium. Therefore, several fully biodegradable scaffolds and drug carried stents had been manufactured using polymers polyester, polycarbonate and polyphosphate, etc. Recently, tissue and blood compatibility securities of present implanted artificial cardiovascular stents manufactured with copolymer materials had been confirmed. However, these stents could not meet the clinical demands because of the respective problems of degradation, material rigidity, flexibility and nonuniformity of support strength. This paper reviews the current and perspective application of polylactie acid （PLA） , polyglycolie acid （PGA） and chitosan in the fabrication of fully biodegradable artificial coronary vascular scaffolds.