Development of a biomimetic composite scaffold to promote vascular network growth

描述（由申请人提供）：促进和指导新血管网生长的新型仿生支架的开发是组织工程成功和慢性伤口愈合快速解决方案的关键障碍。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，支架，模仿血管ECM的机械，化学和地形特性，促进新的血管网络生长速度比传统支架。该项目的长期目标是成功制造促进血管网络生长的仿生支架。本提案的目的是制造新型复合仿生同轴静电纺丝支架，并测试这些支架在体外，离体和体内血管生成模型中促进新血管生长的倾向。在这里，我们的基础支架将是我们建立的部分模拟电纺支架，我们将定制剩余的物理特性以匹配ECM。该提议的中心假设是，模拟血管ECM的多种物理性质的电纺支架将比不模拟血管ECM性质的支架更好地支持新血管生长。我们的基本原理是，通过设计一种促进功能性血管网生长的支架，血管组织可以被纳入组织工程产品中，或者可以用于促进伤口愈合。这些应用中的任何一个的成功都将显著地改变血管组织工程、组织工程和伤口愈合的领域。这项建议与NIH的使命特别相关，该使命涉及对系统行为的基础知识的追求以及这些知识在延长健康寿命方面的应用。在我们的初步数据的指导下，该提议的假设将通过追求三个具体目标进行测试：1）制造血管ECM模拟支架，2）研究在体外和离体的新血管网络生长通过ECM模拟支架，和3）使用鼠伤口愈合模型检查在体内血管生成通过ECM模拟支架。静电纺丝技术将用于制备复杂的复合仿生同轴支架。支架的物理性能将通过纳米压痕、TEM、SEM和测角法进行研究。将使用流式细胞术和针对E-选择素、VE-钙粘蛋白、ICAM等的ELISA研究内皮细胞活化，在细胞培养中，在优化以监测来自自体细胞来源的新血管生成的生物测定室中，以及在鼠模型中。所提出的工作是创新的，因为我们已经开发出一种新的同轴静电纺丝技术，是量身定制的，以提高形成的支架的机械性能。此外，我们还使用了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。我们组建了一个研究团队，拥有成功解决这一重要问题的专业知识和动力。 公共卫生相关性：该项目对组织工程领域的成功非常重要，因为在该项目成功完成后，我们将开发出一种在复杂的复合生物相容性仿生支架内快速制造血管网络的方法。拟议的研究与公共卫生有关，因为我们将获得组织工程多个产品与纳入血管网络和促进慢性伤口愈合的能力。

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. PUBLIC HEALTH RELEVANCE: The proposed project is important to the success of the tissue engineering field because after the successful completion of this project we will have developed a method to rapidly fabricate vascular networks within complex composite biocompatible biomimetic scaffolds. The proposed research has relevance to public health because we will gain the ability to tissue engineer multiple products with incorporated vascular networks and facilitate chronic wound healing.