ANGIOGENIC TISSUE ENGINEERING TO LIMIT POST-INFARCTION VENTRICULAR REMODELING

描述(由申请人提供)：心肌缺血、梗死和心力衰竭构成一种疾病谱，正迅速成为全球最重要的健康挑战之一。目前的治疗方法主要集中在通过经皮冠状动脉介入治疗和冠状动脉旁路移植术进行药物优化和大血管重建术。重建疗法和替代疗法在适用性或可获得性方面受到限制。一个重要的未得到满足的需求是微血管重建。反复研究表明，侧支循环强健的患者具有生存优势。因此，存在内源性血管重建和修复机制，好处是明确的；但天然的效力通常是不够的。在最初的资助阶段，我们研究了内源性微血管重建的主要效应细胞，内皮祖干细胞(EPC)及其强大的趋化因子基质细胞衍生因子1-α(SDF)。我们能够显著增强心肌缺血损伤后微血管的生成，并改善局部组织的生物力学特性、心室几何形状和心功能。通过计算蛋白质工程，我们设计和合成了一种超高效的SDF类似物，并启动了一个项目，将内皮祖细胞嵌入到基于Vitronectin的细胞外基质模拟支架中，以增强细胞的保留和存活。这项工作的内容已经升级到临床前绵羊模型，并转化为最近在我们机构启动的人类临床试验。在这一更新应用中，我们建议进一步深入研究SDF介导的EPC新生血管生成的特定交互机制，开发新的、临床可翻译的传递平台，以增强EPC功能和存活率，并在我们的临床前绵羊模型中对其进行完善，为潜在的人类临床研究做准备。具体目标1将侧重于通过EGFP骨髓重建和跟踪、一种新的心肌特异性SDF条件性基因敲除小鼠以及细胞水平灌流、氧合和能量学的光学荧光定量来阐明机制见解。具体目标2将开发基于生物细胞外基质、细胞片技术和合成三维打印微支架的创新细胞复合材料。具体目标3将把这一治疗策略转变为以微创手术和导管为基础的方法的临床前绵羊模型。我们已经生成了初步的科学组件，并汇集了团队的专业知识，希望能够成功实现这些目标。

DESCRIPTION (provided by applicant): Myocardial ischemia, infarction, and heart failure constitute a disease spectrum which is rapidly becoming one of the foremost global health challenges. Current therapies focus upon pharmacologic optimization and macrorevascularization via PCI and CABG. Reconstructive and replacement therapies are limited in applicability or availability. A significant unmet need is that of microrevascularizatio. Repeated studies have demonstrated survival advantage in patients with robust collateralization. Thus the presence of endogenous revascularization and repair mechanisms exist and the benefits are clear; but the native potency is generally inadequate. In the initial funding period, we studied the primary effectors of endogenous microrevascularization, endothelial progenitor stem cells (EPC) and their potent chemokine stromal cell derived factor 1-alpha (SDF). We were able to significantly augment microvascular angiogenesis and improve local tissue biomechanical properties, ventricular geometry and cardiac function after myocardial ischemic injury. Via computational protein engineering, we then designed and synthesized a supra-efficient SDF analog as well as initiated a project to embed EPCs in a vitronectin-based extracellular-matrix simulating scaffold to enhance cell retention and survival. Elements of this work have been upscaled into a preclinical sheep model and also translated into a recently initiated human clinical trial at our institution. In this renewal application we propose to study in further depth the specific interactive mechanisms underlying SDF-mediated EPC neovasculogenesis, develop novel, clinically translatable delivery platforms that enhance EPC function and survival, and refine these in our preclinical sheep model in preparation for potential human clinical investigation. Specific Aim 1 will focus on elucidating mechanistic insights via eGFP marrow reconstitution and tracking, a novel myocardial-specific SDF conditional knockout mouse, and optical fluorescence quantification of cellular level perfusion, oxygenation and energetics. Specific Aim 2 will develop innovative cellular composites based upon biologic extracellular matrix, cell sheet technology and synthetic 3-dimensional printed microscaffolds. Specific Aim 3 will transition this therapeutic strategy into a preclinical sheep model in minimally invasive operative and catheter- based approaches. We have generated the preliminary scientific components and assembled the team expertise to hopefully successfully achieve these goals.