Development of siRNA-eluting stent using PTD-peptide vector

1. 研究siRNA在支架上的包覆方法。作为模型案例之一，糖基聚糖结合在氧化钛表面。用QCM法测定了碱性PTD肽与gag的结合。此外，还量化了从钛表面摄取肽进入平滑肌细胞的情况。然而;摄取量与对照组无显著差异。我们推测，在细胞播种后，肽不能稳定地结合在钛上。血管平滑肌细胞在支架再狭窄中增殖时，细胞因子可诱导多种基因。我们预测了基质元蛋白酶亚家族ADAM-TS基因在这种情况下的表达。这些可能与再狭窄过程中的重塑有关。因此，在IL-1诱导后3-6小时，ADAM-TS基因中的一个表达上调。该基因的启动子含有假定的nfat结合位点。NFAT抑制剂可以抑制ADAM-TS基因的表达，表明是通过NFAT诱导的。这些结果可能提示siRNA治疗的可能靶点。本课题设计的小支架在大鼠体内进行了试验，支架在主动脉或股动脉内植入，与在股动脉内植入相比，在主动脉内植入是相当成功的。在股动脉内置入支架需要缩小支架的尺寸并增加其灵活性

1. Coating method for siRNA on stent was examined. As one of the model cases, Glycosminoglycans were bound on the titanium oxide surface. A basic PTD peptide binding to GAGs was determined by QCM method. Further, the uptake of the peptide into the smooth muscle cells from the titanium surface was quantified. However; the uptake amount was not significantly different from the control. We suppose that the peptide could not stably bound on titanium after the cells were seeded.2. Various genes are induced by cytokines when the vascular smooth muscle cells proliferate in stent-restenosis. We predicted the ADAM-TS gene, a subfamily of matrix metaroproteinase, expression in this situation. These might be involved in the remodeling in the processes of restenosis. As a result, one of the ADAM-TS gene is upregurated 3-6 hrs after the IL-1 induction. Promoter of the gene contained putative NFAT-binding sites. NFAT inhibitors could suppress the ADAM-TS gene expression, indicating the induction through NFAT. These results might implicate the possible target of siRNA treatment.3. Small stent designed in this project was examined in rat Stent implantation was performed in aorta or femoral artery The implantation in aorta is rather successful compared to that in femoral artery. Narrowing the size and increasing the flexibility is required for stenting in the femoral artery