c-myc反义寡核苷酸涂层支架局部植入给药在体分布及对细胞凋亡的影响

Effects on apoiptosis and distribution of c-myc antisense oligodeoxynucleotides in rabbits after local delivery by gelatin coated platinium-iridium stent

目的 :评价c myc反义寡核苷酸 (ASODN)经铂 -铱合金明胶蛋白涂层支架局部应用后 ,药物在组织中的分布及对血管平滑肌细胞凋亡的影响。方法 :将携带羧基荧光素 (FAM )标记c mycASODN的国产铂 铱合金明胶蛋白涂层支架 (5 5 0 μg/支架 )置入兔颈动脉 (n =6 ) ,术后 4 5min、2h、6h分别取材 ,荧光显微镜下观察药物在脏器中的分布。另取家兔 32只 ,对照组 16只置入明胶蛋白涂层支架 ;处理组 16只置入携带c mycASODN明胶蛋白涂层支架。术后 7、14、30、90d(均n =4 ) ,取置入支架血管 ,行组织病理学检查 ,观察新生内膜增殖、细胞凋亡和c myc表达。结果 :给药后镜下观察药物主要分布于靶点血管。处理组平均新生内膜厚度与新生内膜面积均较对照组小(均P <0 .0 1)。术后 30d在新生内膜中观察到明显的细胞凋亡 ,90d时单位面积内凋亡细胞数显著高于 30d ;同时 ,处理组VSMC的凋亡数显著高于对照组。对照组新生内膜中c myc蛋白免疫组化及原位杂交均为阳性 ,处理组术后 7、14d为阴性 ,30、90d为弱阳性。结论 :明胶蛋白涂层支架介导的局部给药简便、可行。c mycASODN在体导入后 ,抑制VSMC增殖 ,诱导VSMC凋亡。

AIM: To assess tissue distribution and effect on vascular smooth muscle cells (VSMCs) apoptosis of c-myc antisense oligodeoxynucleotides (ASODN) local delivery by gelatin coated Platinium-Iridium (Pt-Ir) stent. METHODS: Gelatin coated Pt-Ir stent absorbed FAM (caroboxyfluorescein-5-succimidyl ester ) labeled c-myc ASODN (550 μg per stent) were implanted into the right carotid arteries of 6 rabbits under vision. The samples were obtained at 45 min、2 h and 6 h. Tissue distribution of c-myc ASODN was assessed by fluorescence microscopy. Take another 32 rabbits, the first group was implanted gelatin coated Pt-Ir stent, the second group was implanted gelatin coated stent absorbed c-myc ASODN (n=16,respectively). 7 、14、30 and 90 days (n=4,respectively) after the stenting procedure, the stented segments were harvested,histopathology for elvaluating neointimal proliferation,VSMCs apoptosis and c-myc expression were performed. RESULTS:FAM labeled c-myc ASODN was most intense in target vessel. Morphometric analysis showed that the value of neointimal area and mean neointimal thickness was less in the second group than in the first group (P<0.01, respectively). The apoptotic cells occurred in the neointima 30 and 90 days after stenting, and the number of apoptotic cells were less at 30 days than at 90 days. Meanwhile c-myc ASODN induced more apoptotic cells than the first group. c-myc expression was positive in the first group and negative or weak positive in c-myc ASODN treated group by ISH and immunohistochemical methods. CONCLUSION: Gelatin coated Pt-Ir stent mediated local delivery of c-myc ASODN is feasibility. c-myc ASODN can inhibit VSMC proliferation and induce VSMCs apoptosis after local delivery in vivo.