혈관 스텐트의 재내피화를 위한 생체분자를 이용한 표면개질

Abstract

Recently, the technique and coatings for stent fabrication are providing for clinical devices, particularly before antiproliferative drug therapy within a body of a patient in order to prevent excessive restenosis and to avoid late thrombosis. Development of percutaneous transluminal angioplasty (PTA) has been a chief therapeutic method for treatment for resolving these phenomena. However, the incomplete re-endothelialization, neointimal hyperplasia, restenosis, and thrombosis induced by smooth muscle cells (SMCs) hinder the long-term clinical success. We are studying the selective/sensitive polymeric surface for increasing a specific adsorption of endothelial cells (ECs) and decreasing in nonspecific adsorption of SMCs. First, some ligands, well known as combinable and adhesive materials with ECs, are introduced on biopolymer surface for improving a specific adhesuin of ECs. The modified polymer surfaces were characterized by contact angles, XPS, and FE-SEM. Second, a native extracellular matrix (ECM) environment may provide a favorable microenvironment for ECs on the surface of stent. Using SMCs-derived matrix, ECs adhesion and proliferation were investigated. SMCs were cultured for 10 days on coverslip. Preparation of SMCs-derived extracellular matrix (SDM) were carried out by using Triton X-100 detergent and enzymes. The SDMs were then treated with 0.1% glutaraldehyde, and washed gently with 0.1M glycine. SDM were characterized by field emission scanning electron microscope (FE-SEM), immunofluorescent staining and contact angle measurement. After, ECs and SMCs were seeded (1x104 cells/well) on the SDM, cell proliferation was measured by cell counting kit (CCK-8), cell morphology was also observed by FE-SEM at 3 and 12 hr, respectively. PLLA surface was also clarified by XPS and contact angle data show that RGD, REDV, and LDV were successfully grafted on the PLLA films. Although REDV and LDV sequences have the specific interaction to endothelial cells, they did not significantly improve the endothelial cell adhesion. A modular design approach to smooth muscle cell-derived proteins has been successfully demonstrated. The growth rate of ECs was not significantly different between gelatin and SDM . Although further study remains, naturally derived SDM is a good source in investigating cell-matrix interaction, especially EC and nearby ECM.