Increasing biocompatibility of stents through CD47 functionalization

描述（由申请人提供）：与血管内支架使用相关的病理生理学有很好的记录，并且在接受医疗器械的所有患者中观察到高达50%。不幸的是，一直缺乏创新的解决方案，以防止不良影响，如支架内再狭窄和新生内膜形成，心血管支架部署。使用生物活性治疗分子使医疗器械的血液接触面具有生物功能，理论上可以减轻支架使用中观察到的异常血液相容性问题。CD47已被确定为免疫抑制受体SIRP¿的配体，并已被证明在异种移植的红细胞和合成纳米颗粒上赋予“自我”状态。Stanley J. Stachelek博士是该项目的共同主要研究者（PI）之一，也是心血管生物材料炎症反应开发策略的专家，他最近描述了一种平台技术，通过将普遍表达的细胞表面蛋白CD47与聚合物表面共价连接，来减少对一系列生物材料（如聚氯乙烯（PVC）和聚氨酯（PU））的炎症反应。为了补充Stachelek博士的专业知识，该项目的另一位共同负责人Ilia Fishbein博士发表了大量关于开发新的创新策略以增强血管内支架生物相容性的文章。借鉴这两位研究者的专业知识，本提案将验证重组CD47可以固定在血管内支架表面以减少支架部署后观察到的促血栓和促炎症事件的假设。该提案将有两个具体目标。在第一个目标中，研究人员将优化重组CD47在不锈钢表面的附着。进一步的研究将使用体外和离体方法来表征CD47功能化金属表面的抗炎特性。然后，CD47修饰金属表面的铅制剂将用于第二个也是最后一个特定目标，其中一个大鼠支架血管成形术模型将用于评估CD47修饰支架在增强血液相容性和减少新内膜形成和支架内再狭窄方面的功效。该提案融合了心脏病学、合成化学、免疫学和材料科学的专业知识和概念，将有助于开发一种新颖和创新的治疗策略，以解决心血管支架使用的异常影响。

DESCRIPTION (provided by applicant): The pathophysiology associated with endovascular stent usage is well documented and is observed in up to 50% of all patients receiving the medical device. Unfortunately there has been a paucity of innovative solutions to prevent the untoward effects, such as in-stent restenosis and neointimal formation, of cardiovascular stent deployment. Biofunctionalizing the blood-contacting surface of medical devices, with bioactive therapeutic molecules, would hypothetically attenuate the aberrant hemocompatibility issues that are observed in stent usage. CD47 has been identified as a ligand for the immune inhibitory receptor SIRP¿ and has been shown to confer "self" status on xenotransplanted red blood cells and synthetic nanoparticles. Dr. Stanley J. Stachelek, one of this project's co-Principle Investigator (PI) and an expert on developing strategies to address the inflammatory response to cardiovascular biomaterials, has recently described a platform technology to reduce the inflammatory response to a range of biomaterials such as polyvinyl chloride (PVC) and polyurethane (PU), by covalently linking a ubiquitously expressed cell surface protein, CD47, to the polymers' surface. Complementing Dr. Stachelek's expertise, Dr. Ilia Fishbein, M.D., Ph.D., the other co-PI on the project, has published extensively on developing new and innovative strategies to enhance endovascular stent biocompatibility. Drawing from the expertise of these two investigators, this proposal will test the hypothesis that recombinant CD47 can be immobilized onto the surface of endovascular stents to decrease the pro-thrombotic and pro-inflammatory events that are observed after stent deployment. The proposal will have two Specific Aims. In the first aim, the investigators will optimize the attachment of recombinant CD47 to stainless steel surfaces. Additional studies will be performed to characterize, using in vitro and ex vivo methodologies, the anti-inflammatory properties of CD47 functionalized metal surfaces. Lead formulations of CD47 modified metal surfaces will then be used in the second and final Specific Aim where a rat model of stenting angioplasty will be used to assess the efficacy of CD47 modified stents in enhancing hemocompatibility and reducing neointimal formation and in-stent restenosis. This proposal, which blends expertise and concepts from cardiology, synthetic chemistry, immunology, and materials science will contribute to developing a novel and innovative therapeutic strategy to address the aberrant effects of cardiovascular stent usage.