包裹支架转移治疗基因到猪冠状动脉的实验研究

Novel Biosynthetic Stent Coating Capable of Local Gene Delivery in Porcine Coronary Artery

【目的】寻找一种有效转送治疗基因到扩张冠状动脉的靶部位的运载工具,用于预防冠状动脉损伤后再狭窄。【方法】治疗组用高分子聚合物phosphorylocholine(PC)包裹不锈钢丝的包裹支架,对照组用非包裹支架。①体外研究:经用复制缺陷的重组腺病毒β-Gal(1x109pfu/ml)处理后,将支架植入刚获得的新鲜猪冠状动脉内,植入了支架的冠状动脉分别用一种液体冲洗,共分成5组,每组5例,1组无冲洗、2组生理盐水、3组造影剂、4组血液、5组培养液。对照组用生理盐水冲洗。然后培养48h后固定,X-Gal染色,进行组织学分析。②在体研究:支架经用复制缺陷的重组腺病毒RvdTIMP3处理后,植入猪的冠状动脉,7d后处死猪,取血标本作血液学检验。心脏、脑、肺、肝、脾组织、部分冠状动脉靶部位置入液氮保存,作PCR分析。【结果】①体外包裹支架传移率分别为:无冲洗组6.9%±3.7%,生理盐水组6.6%±3.6%,培养液组7.2%±2.5%,造影剂组7.4%±1.9%,血液组16.2%±9.3%。对照组1.9%±0.5%,与生理盐水冲洗的治疗组比较差异有显著性,P=0.025。②仅治疗组在治疗部位的冠状动脉及远端血管组织中有TIMP3出现,其他器官组织中均未发现有TIMP3。【结论】经PC包裹的支架可有效地输送含有治疗基因的腺病毒到冠状动脉靶部位,液体的冲洗对传移率无明显影响,这?

Objective] To develop a suitable vehicle for local delivery of adenovirus to coronaries, offering promise for the use of therapeutic viruses to prevent restenosis. A novel coated stent , PC 2028 (Biocompatibles, Farnham, U.K.) was tested. Uncoated stents were used in the control groups. ① In vitro Work: Freshly harvested porcine coronary arteries were stented with b Gal pre treated PC 2028 coated stents and flushed with one of five solutions (n=5 for each group) no flush, 0.9% saline, contrast medium, culture medium or blood. Uncoated stents were used as control and flushed with 0.9% Saline. Stented segments were then cultured for 48 hours, prior to fixation and X Gal staining. Transduction was quantified both macroscopically (% area stained blue) & histologically using Image Pro 4.1.② In vivo Work: TIMP3 virus treated PC 2028 stents were deployed in porcine coronary arteries under radiographic control.Blood, coronaries and major organs were then harvested following 7 days. In addition to transduction quantification (as with in vitro experiments), PCR was performed on all harvested tissue samples to assess the systemic distribution of the virus and confirm local delivery to the stented coronary artery. ① PC stainless steel coupons showed superior transduction compared to uncoated coupons. Transduction rates for the in vitro PC stents were quantified at a macroscopic level: no flush 6.9% ± 3.7% , 0.9% saline 6.6% ± 3.6% ,culture media 7.2% ± 2.5% , contrast media 7.4% ± 1.9% , and blood 16.2% ± 9.3% . Transduction rate for uncoated stent was1.89% ± 0.47% , significantly lower than that of PC stent, P =0.025? ② In vivo, we could demonstrate localized transduction within the stented area, without systemic distribution of the virus. [ Conclusion] Our results demonstrate effective and targeted, in vitro and in vivo, transduction of adenovirus from a stent using a novel biosynthetic coating to coronaries. With the advent of highly specific viral vectors and an increasing library of genetic targets for the manipulation of vascular pathology, this coated stent could be a suitable vehicle for future management of in stent restenosis.