【作者】 刘斌；

【导师】 李淑梅；

【作者基本信息】 吉林大学 ， 内科学， 2007， 博士

【摘要】 目的:开发一种新型的CD34抗体包被多聚物涂层支架,探讨支架在防止再狭窄中的可行性、安全性和有效性。方法:用高分子化学合成法制备PEG-PLA-PGL材料,动物实验评价该材料的生物相容性,高分子接枝改性对金属支架表面化学处理,SPDP法制成CD34抗体洗脱支架,动物实验评价其对支架植入术后的犬内膜增生的影响。结果:1、PEG-PLA-PGL降解性能满足支架需要。2、酸浓度为0.20,处理0.5-6h为最佳表面处理条件。3、SPDP法可将CD34抗体稳定地包被到PEG-PLA- PGL上。4、EPCs可在包被有CD34抗体的PEG-PLA- PGL膜上稳定生长,并逐渐分化为内皮细胞,形成良好内皮细胞层。5、PEG-PLA- PGL具有良好的生物相容性,作为载体材料具有良好的安全性和可行性。6、CD34抗体包被支架与裸支架、药物涂层支架相比,能明显加速内皮修复,降低再狭窄的发生。结论:1、PEG-PLA- PGL在合成、降解和接枝上满足支架载体材料的需要。2、SPDP法为可行的CD34抗体包被多聚物涂层支架的方法。3、CD34抗体支架可减少支架置入术后的内膜增生,在预防再狭窄上具有良好的可行性、安全性和有效性。更多还原

【Abstract】 In-stent restenosis(ISR) is the major drawback of percutaneous coronary interventions which is increasingly attracting interests of medical science. Research of drug eluting stents (DES) is very popular because DES are successful in a large majority of patients in preventing restenosis. The currently available drug-eluting stents have been thought to increase the risk of thrombosis by delayed endothelialization as endothelial progenitor cell proliferation is also inhibited. As the defect mentioned above, a novel stent is being expoldered to prevent thrombosis , to inhibit neointimal hyperplasia when bare stent is exposed to blood circulation ,and to reduce the incidence of in-stent restenosis by accelerating endothelialization.The research firstly synthesized a new degradable tri-block copolymers PEG-PLA-PGL which has active groups, and then treated the surface of the metal stent by chemistry technology , connected the stent and the antibody against CD34 . The anti-CD34 antibody was bounded with the polymer by N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) conjugation technology so as to establish anti-CD34 antibody eluting stent. And we evaluated the feasibility, safety and effectiveness of the stent in preventing restenosis in animal experiments.The investigation indicated: 1、ratio of 17:23:63 among PEG、PLA and PGL, molecular weight of 18.0 and 14.6(×103) Da, had stable degradable property , and satisfied the time of complete endothelialization . The results showed that in flowing solution ,the changes of weight and molecular weight were more slowly compared with static degradation .That attributes to the micro-circumstance on polymer surface.2、We connected the stent and the antibody against CD34 by treating the surface of the metal and introducing coupling agent. We initially detected the static state contact angle to estimate the bonding force between coating and stent , and to evaluate the effects of both acid density and treating persistence time towards polymer spreading on stent surface. We discovered that when the acid density sustained in the level of 0.20mmol/L,the contact angle almost achieved to the minimal level, that is to say that the surface energy of stent and bonding force is both strongest at that time. We also discovered that when the treating persistence time maintained at the level of 0.5 to 6 hours, the contact angle would increasingly small, and on the other hand, it seemed to raise when the treating time beyond 6 hours. That attributed to the surface roughness and so on. 3、We successfully connected the antibody against CD34 and the biodegradable polymer of PEG–PLA–PGL by N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) conjugation technology. 4、The way that anti-CD34 antibody was bounded to the polymer by N-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) conjugation technology was very successful and better than mechanical adherence. 5、Endothelial progenitor cell grew in a stable way in stents coated with CD34 antibody carried by tri-block copolymers PEG-PLA-PGL. And endothelial progenitor cell matured towards endothelial cell and established active layers of endothelial cell at last . The experiment indicated that the CD34 antibody eluting stent could capture endothelial progenitor cell effectively and accelerate endothelialization. 6、PEG-PLA-PGL has fine biocompatibility, which is feasible and safe for clinical application as carrier of drug eluting stents.7、The stent coated with antibody against CD34 carried by the degradable polymer maybe useful for reducing in-stent restenosis by accelerating endothelialization compared with the bare metal stent.The results of this experiment could lead to profound investigation of polymers as coatings of novel stents. Our research provides new theory and experiment evidence for further exploring novel polymer coating of metal stent .Through small animals experiments, The next step we will do is to evaluate the long term effects of stent coated with CD34 antibody carried by biodegradable polymer to ISR of he lesions of coronary arteries .更多还原