Anisotropic Human Mesenchymal Stem Cell Patch with Oriented Vasculature

病变组织的替换要求植入的材料不仅具有适当的机械强度，而且还必须具有正常运作的血液分配网络(血管、静脉和毛细血管)，而这些往往很难制造。这个项目将寻求了解和模拟三维(3D)心脏组织的结构和血管系统。其目标是设计出一种机械强度高、功能强大的细胞贴片，用于受损心脏组织的再生。这项拟议的研究还将为本科生和研究生以及代表性不足的社区大学生提供参与跨学科干细胞和组织工程研究的机会。此外，还将举办一系列研讨会，以提高密歇根州北部(上半岛)卫生界和公众对干细胞和组织工程学的认识。该项目的总体目标是创建排列好的纳米纤维天然细胞外基质(ECM)支架，用于生物构建预血管各向异性干细胞补片，并阐明体内微环境中微血管定向的机制。人骨髓间充质干细胞(HMSCs)具有免疫调节、再生、促进心肌再生等功能，具有稳定内皮细胞(ECs)形成的微血管的周细胞功能。这些独特的特性使得hMSCs能够与ECM支架和ECs结合来生物富含现成的或患者特有的预血管补片，在其中hMSCs将发挥稳定ECs在体外形成的血管和协调植入后死亡心脏组织再生的双重作用。在本项目中，hMSCs将与内皮细胞在纳米纤维状ECM支架中共培养，形成排列的毛细管状血管系统，并研究排列的纳米纤维对微血管密度、取向和成熟的影响。预血管化的hMSC片材将在灌流生物反应器中进行多层和进一步的成熟，并将评估生理性间质流动对3D仿生组织平台内现有微血管的相互连接、对准和成熟的作用。如果成功，该项目可能导致个性化或现成的心脏组织贴片的开发，从而极大地提高治疗与心脏病发作相关的死亡心肌的成功率。

Replacement of diseased tissue requires that the implanted material not only have the proper mechanical strength, but it must also have a functioning blood distribution network (vasculature; veins, capillaries), and these are often difficult to manufacture. This project will seek to understand and mimic the structure and vasculature of three-dimensional (3D) cardiac tissue. The goal is to engineer a mechanically strong and functional cell patch for the regeneration of damaged heart tissue. The proposed research will also provide opportunities for undergraduate and graduate students, as well as underrepresented community college students, to be involved in interdisciplinary stem cell and tissue engineering research. In addition, a series of seminars will be hosted to increase stem cell and tissue engineering awareness among the health community and public in the UP (Upper Peninsula) of Michigan. The overall objective of the project is to create aligned nanofibrous natural extracellular matrix (ECM) scaffolds for the biofabrication of a prevascularized anisotropic stem cell patch and elucidate the mechanism of microvessel orientation within the in vivo microenvironment. Human mesenchymal stem cells (hMSCs) are immunoregulatory, regenerative, effective in promoting myocardial regeneration, and function as pericytes to stabilize the microvessels formed by endothelial cells (ECs). These unique properties enable hMSCs to combine with ECM scaffolds and ECs to biofabricate an off-the-shelf or patient-specific prevascularized patch, in which hMSCs will play a dual role of stabilizing vasculature formed by ECs in vitro and orchestrating the regeneration of dead cardiac tissue after implantation. In this project, hMSCs will be co-cultured with ECs in a nanofibrous ECM scaffold to form an aligned capillary-like vasculature, and the effects of aligned nanofibers on the density, orientation and maturation of the microvessels will be investigated. The prevascularized hMSC sheets will be multi-layered and further matured in a perfusion bioreactor, and the role of physiological interstitial flow on the inter-connections, alignment and maturation of the existing microvessels within the 3D biomimetic tissue platform will be evaluated. If successful, this project could lead to the development of personalized or off-the-shelf cardiac tissue patches that could dramatically increase the success rate for the treatment of dead cardiac muscle associated with heart attacks.