Fiber-reinforced hydrogels to guide the formation and integration of engineered microvasculature

项目摘要 组织工程和再生医学是一个快速发展的领域，努力发展生物结构 恢复、维持或改善组织或器官的功能。尽管过去几十年来有报道称 尽管在相对薄的非血管化组织中获得成功，但大的复杂组织的发育需要 植入后整个结构的血液供应充足。具体而言，快速整合（约1天） 工程脉管系统通过向活体内的所有细胞提供营养和氧气而对移植物存活至关重要 构建体虽然许多人已经报道了血管网络在体外的成功组装，但血管成熟和 植入后与宿主脉管系统的快速吻合仍然是重大的挑战。因此，长期目标 这项工作的目的是建立一种预血管化的生物材料，支持快速的宿主整合， 灌注。为实现这一目标，本提案的总体目标是了解企业内容管理实体 性质，特别是纤维微结构，在1）调节内皮细胞（EC）的自组装成一个 成熟的血管网和2）促进植入后的宿主细胞侵袭和整合。我们的中央 一种假设是，将纤维结构掺入合成水凝胶中将增加组装速率 以及在植入时增加宿主细胞侵袭，这两者都将导致 更快的吻合和体内灌注。我们利用静电纺丝纤维基质的初步数据支持 这一假设表明，可变形的纤维微环境促进了机械通信 在内皮细胞之间，是多细胞结构形成和成熟的基础。在第一个目标中，我们将利用 3D纤维增强葡聚糖乙烯砜（DexVS）合成水凝胶，以研究机械性能的作用。 在功能性微血管网络的形成和成熟中起重要作用。我们将首先确定 支持长距离力传递的最佳物理基质条件（例如体积刚度、纤维密度） 和通过量化细胞力介导的3D基质变形的机械通信。此外，我们将 利用这些结果来智能地设计纤维DexVS水凝胶， 功能性血管网这些网络的成熟度将通过量化网络形态来分析， 细胞-细胞连接的强度，以及微流体装置内的微流动和灌注。在目标2中，我们 确定预血管化纤维DexVS基质支持SCID中快速宿主植入的能力- 小鼠皮下模型。将在第一周内的不同时间点从小鼠解剖植入物， 量化植入血管的灌注率以及宿主细胞侵入移植物。这一贡献 工作预计是一种新型的合成纤维生物材料，支持快速血管形成和宿主 移植以及更好地了解生物材料的物理特性如何调节移植的成功 预血管化组织构建体。从这些研究中收集到的信息对于促进 组织工程和再生医学应用的生物材料设计。

PROJECT SUMMARY Tissue engineering and regenerative medicine is a rapidly growing field striving to develop biological constructs that restore, maintain, or improve the function of a tissue or organ. While the past few decades have reported success in relatively thin non-vascularized tissues, the development of large and complex tissues requires adequate blood supply throughout the construct upon implantation. Specifically, rapid integration (~1 day) of engineered vasculature is essential to graft survival by providing nutrients and oxygen to all cells within the living construct. While many have reported successful assembly of vascular networks in vitro, vessel maturation and rapid anastomosis to host vasculature post-implantation remain significant challenges. Thus, the long-term goal of this work is to establish a prevascularized biomaterial that supports rapid host integration and subsequent perfusion. Towards this goal, the overall objective of this proposal is to understand the role of ECM physical properties, specifically fibrous microstructure, in 1) regulating the self-assembly of endothelial cells (ECs) into a mature vascular network and 2) promoting host cell invasion and integration upon implantation. Our central hypothesis is that the incorporation of fibrous structure into synthetic hydrogels will increase the rate of assembly and maturation of microvessels as well as increase host cell invasion upon implantation, both of which will lead to faster anastomosis and perfusion in vivo. Our preliminary data utilizing electrospun fibrous matrices supports this hypothesis, indicating that deformable fibrous microenvironments promote mechanical communication between ECs that underlies the formation and maturation of multicellular structures. In the first aim we will utilize 3D fiber reinforced dextran vinyl sulfone (DexVS) synthetic hydrogels to investigate the role of mechanical communication in the formation and maturation of functional microvascular networks. We will first determine optimal physical matrix conditions (e.g. bulk stiffness, fiber density) that support long range force transmission and mechanical communication by quantifying cell force mediated 3D matrix deformations. Additionally, we will utilize these results to intelligently design fibrous DexVS hydrogels that promote rapid formation of mature, functional vascular networks. Maturation of these networks will be analyzed by quantifying network morphology, strength of cell-cell junctions, and anastomoses and perfusion within a microfluidic device. In Aim 2, we will determine the ability of prevascularized fibrous DexVS matrices to support rapid host engraftment in a SCID- mouse subcutaneous model. Implants will be dissected from mice at various time points within the first week to quantify perfusion rate of implanted vessels as well as host cell invasion into the graft. The contribution of this work is expected to be a novel synthetic fibrous biomaterial that supports rapid vessel formation and host engraftment as well as a better understanding of how biomaterial physical properties regulate the success of prevascularized tissue constructs. The information gleaned from these studies will be critical to the advancement of biomaterial design for tissue engineering and regenerative medicine applications.