药物洗脱支架和内皮细胞种植支架的生物相容性

Biocompatibility of drug-eluting stent and stent seeded with endothelial cells

目前用于临床的药物洗脱支架包括雷帕霉素洗脱支架和紫杉醇洗脱支架,雷帕霉素和紫杉醇在抑制血管平滑肌增殖和迁移的同时,也抑制了内皮细胞的正常恢复,抑制支架植入后剥脱内膜的再内皮化过程,中药川芎嗪和大蒜素既能抑制新生内膜增生,又能促进损伤动脉内皮化,成为目前研究较多的涂层药物。由于血管内膜及血管内皮细胞受损在再狭窄中起到至关重要的作用,以血管内皮细胞为靶向的干预措施成为人们研究的重点,在支架表面种植内皮细胞或内皮祖细胞,通过细胞释放的活性因子可以抑制血栓的形成及平滑肌细胞的过度增生。光滑的材料表面对药物涂层和内皮细胞的种植非常不利,主要表现为细胞的脱落、涂层不均匀等,材料表面粗糙度的研究在提高细胞黏附率,预防支架植入后血栓形成和再狭窄中起着重要的作用。

Rapamycin and taxinol-eluting stents are commonly used in clinic. Rapamycin and taxinol can inhibit vascular smooth muscle proliferation and migration, suppress endothelial cell normal recovery, and inhibit reendothelialization following stenting. Chinese herbs such as Ligustrazine and allicin can inhibit newly-formed intimal hyperplasia and promote injured artery endothelialization, and have become commonly used eluting drugs. As vascular intima and vascular endothelial cell injuries play important roles in restenosis, interventions targeting to vascular endothelial cells has become study focus. Vascular endothelial cells or endothelial progenitor cells seeding on the surface of stent can inhibit thrombosis and vascular smooth muscle hyperplasia though active factors released from cells. Smooth stent surface is adverse to drug-eluting and cell seeding, resulting in cell shedding, even eluting and so on. Surface roughness can improve cell attachment, prevent thrombosis following stent implantation and restenosis.