MICROFABRICATED 3D VASCULARIZED CARDIAC TISSUE CONSTRUCTS

描述(由申请人提供)：由心肌细胞(CMS)丢失或功能障碍引起的心血管疾病是导致死亡的主要原因，影响全球数百万人。组织工程学在修复受损心脏方面大有可为，但需要功能性组织结构的工程化。目前心血管组织工程方法的一些关键局限性包括无法产生细胞负载和细胞黏附的生物材料，无法设计血管组织，无法模拟心脏组织的生物复杂性和微结构。为了应对这些挑战，我们的目标是将创新的微尺度技术与先进的生物材料(即水凝胶)相结合，创建细胞载水凝胶，并开发具有可控物理和生物特性的3D血管心脏组织结构。我们将主要使用天然基光交联性水凝胶(明胶甲基丙烯酸酯，GelMA)来开发高度有序的3D血管网络。具体地说，我们将在图案化水凝胶中共培养内皮细胞(ECs)和间充质干细胞(MSCs)，构建和诱导MSCs向平滑肌细胞分化，并开发具有可控几何特征和生物学特性的仿生血管。然后，我们将心肌细胞包裹在另一层水凝胶中，并将其与预先开发的血管网络结合起来，生成具有不同构型和可控复杂性的心肌组织结构。通过CMS与排列的ECs和MSCs的三重培养，我们将广泛地研究组织结构的生物学特性。此外, 我们将测试开发的血管化结构在循环拉伸条件下的功能。最后，我们将评估体内构建的工程化心脏组织的功能特性。该项目的成果将对心血管组织再生具有重要意义，其中基质材料的性质和形态在维持心脏和血管组织的天然结构结构方面发挥着重要作用。此外，所开发的构建物可作为药物细胞毒性研究的综合平台。

DESCRIPTION (provided by applicant): Cardiovascular diseases caused by the loss or dysfunction of cardiomyocytes (CMs) are the leading cause of death and affect millions of people worldwide. Tissue engineering holds great promise for the repair of injured hearts but requires the engineering of functional tissue constructs. Some of the key limitations of current cardiovascular tissue engineering approaches include the inability to generate cell-laden and cell- adhesive biomaterials, engineer vascularized tissues, and mimic the biological complexity and microarchitecture of cardiac tissues. To address these challenges, we aim to combine innovative microscale technology and advanced biomaterials (i.e. hydrogels) to create cell-laden hydrogels and develop 3D vascularized cardiac tissue constructs with controlled physical and biological properties. We will primarily use natural-based photocrosslinkable hydrogels (gelatin methacrylate, GelMA) to develop highly organized 3D vascularized networks. Specifically, we will co-culture endothelial cells (ECs) and mesenchymal stem cells (MSCs) within the patterned hydrogel construct and induce MSCs differentiation toward smooth muscle cells and develop biomimetic vasculature with controlled geometrical features and biological characteristics. Then, we will encapsulate cardiomyocytes within another layer of hydrogel and combine it with the pre- developed vascularized networks to generate cardiac tissue constructs with variable configurations and controlled complexities. Through the triple-culture of CMs with aligned ECs and MSCs, we will extensively study the biological properties of the tissue construct. In addition, we will test the functionality of the developed vascularized construct under cyclically stretched conditions. Finally, we will assess the functional properties of the engineered cardiac tissue construct in vivo. Achievements in this project will be important for cardiovascular tissue regeneration where the matrix material properties and configuration play an important role in maintaining native structural architecture of cardiac and vascular tissues. In addition, the developed constructs can be used as an integrative platform for drug cytotoxicity studies.