Development of a BioMIMETIC Composite Scaffold to promote vascular network growth

描述（由申请人提供）：开发新型仿生支架，促进和指导新血管网络的生长，是组织工程成功的关键障碍，也是慢性伤口愈合的快速解决方案。传统上，仿生支架只匹配细胞外基质（ECM）纤维直径，但我们的初步结果表明，模仿血管ECM的机械、化学和地形特性的支架比传统支架更快地促进了新血管网络的生长。该项目的长期目标是成功地制造促进血管网络生长的仿生支架。本研究的目的是制备新型复合仿生同轴静电纺丝支架，并在体外、离体和体内血管生成模型中测试这些支架促进新血管生长的倾向。在这里，我们的基础支架将是我们已经建立的部分模拟静电纺丝支架，我们将调整其余的物理特性以匹配ECM。该提案的中心假设是，与不模拟血管外膜特性的支架相比，模拟血管外膜多种物理特性的电纺丝支架将更好地支持新血管的生长。我们的基本原理是，通过设计一个支架，促进功能性血管网络的生长，血管组织可以纳入组织工程产品或可用于促进伤口愈合。这些应用中的任何一个的成功，都将显著改变血管组织工程、组织工程和伤口愈合领域。这一建议与NIH的使命特别相关，即追求有关系统行为的基本知识，并应用这些知识来延长健康生命。在我们的初步数据的指导下，我们将通过三个具体目标来验证这一假设：1)制造血管ECM模拟支架，2)研究体外和离体ECM模拟支架中新血管网络的生长，以及3)使用小鼠伤口愈合模型来研究ECM模拟支架在体内的血管生成。静电纺丝将用于制造复杂的复合仿生同轴支架。用纳米压痕、透射电镜、扫描电镜和角度测量法研究支架的物理性能。内皮细胞的激活将通过流式细胞术和ELISA技术在细胞培养、生物测定室（用于监测来自自体细胞源的新血管生成）和小鼠模型中针对e -选择素、ve -钙粘蛋白、ICAM等进行研究。提出的工作是创新的，因为我们已经开发了一种新的同轴静电纺丝技术，专门用于提高成型支架的机械性能。同时，我们使用这个小组开发的促血管生成生物测定室。这项研究将对组织工程/伤口愈合研究产生积极影响，并且具有重要意义，因为我们将开发一种在生物相容性仿生支架内制造新血管网络的技术。我们已经组建了一支具有专业知识和动力的研究团队，以成功解决这一重要问题。

DESCRIPTION (provided by applicant): The development of novel biomimetic scaffolds that promote and direct new vascular network growth is a critical hurdle for the success of tissue engineering and for a rapid solution for chronic wound healing. Traditionally, biomimetic scaffolds only match the extracellular matrix (ECM) fiber diameter, but our preliminary results suggest that scaffolds that mimic the mechanical, chemical and topographical properties of the vascular ECM promote new vascular network growth faster than traditional scaffolds. The long-term goal of this project is too successful fabricate biomimetic scaffolds that promote vascular network growth. The objective of this proposal is to fabricate novel composite biomimetic coaxial electrospun scaffolds and to test the propensity of these scaffolds to promote new vascular growth in an in vitro, ex vivo and in vivo angiogenesis model. Here our base scaffolds will be our established partially mimetic electrospun scaffolds and we will tailor the remaining physical properties to match the ECM. The central hypothesis of this proposal is that electrospun scaffolds that mimic multiple physical properties of the vascular ECM will support new vessel growth better than scaffolds that do not mimic the vascular ECM properties. Our rationale is that by designing a scaffold that facilitates functional vascular network growth, vascular tissue can be incorporated into tissue engineered products or can be used to facilitate wound healing. The success of either of these applications, would significantly transform the fields of vascular tissue engineering, tissue engineering and wound healing. This proposal is especially relevant to the NIH's mission that pertains to the pursuit of fundamental knowledge about the behavior of systems and the application of that knowledge to extend healthy life. Guided by our preliminary data, the hypothesis of this proposal will be tested by pursing three specific aims: 1) To fabricate vascular ECM mimicking scaffolds, 2) To investigate the in vitro and ex vivo new vascular network growth throughout ECM mimicking scaffolds, and 3) To examine in vivo angiogenesis throughout ECM mimicking scaffolds using a murine wound healing model. Electrospinning will be used to fabricate complex composite biomimetic coaxial scaffolds. Scaffold physical properties will be investigated with nanoindentation, TEM, SEM and goniometry. Endothelial cell activation will be investigated with flow cytometry and ELISA directed towards E-selectin, VE-cadherin, ICAM, etc., in cell culture, in a bioassay chamber optimized to monitor new angiogenesis from an autologous cell source and in a murine model. The proposed work is innovative because we have developed a new coaxial electrospinning technique that is tailored to enhance the mechanical properties of formed scaffolds. Also, we use a pro-angiogenic bioassay chamber that was developed by this group. This research will have a positive impact on tissue engineering/wound healing research and is significant because we will develop a technique to fabricate new vascular networks within a biocompatible biomimetic scaffold. We have put together a research team that has the expertise and drive to successfully address this important question.