DEGRADABLE SCAFFOLDS FOR GENETICALLY ENGINEERED GRAFTS

这项提议的目标是开发用于 心血管组织工程将导致生产 以组织为基础的小直径血管移植。水凝胶聚合物支架 将通过水前驱体的快速光聚合形成 允许将细胞悬浮液合并到最终的 产品。在这个过程中，细胞的活力是保持的，而 重点将放在使用基因工程的平滑肌和 内皮细胞。多种生物活性结构域的结合 在水凝胶结构内的基质将被研究以 促进细胞黏附、生长和细胞外基质合成。 纳入的生物活性结构域将包括细胞粘附肽 和多肽生长因子。细胞将被转导到 编码一氧化氮合酶以产生一氧化氮合酶(一种已证实的抗血栓药物)， 一种内皮细胞特异性生长因子(VEGF)，赖氨酰氧化酶 增强基质交联剂和蛋白水解酶抑制物(TIMPs)以减少 基质降解。细胞活性的体外评估和 增殖、细胞外基质合成和转基因表达 将在流动和静态培养条件下进行。高聚物 制剂和聚合物/细胞复合材料将使用小型 动物体内血管损伤模型中血管内皮细胞的募集 细胞与维持动态平衡。涤纶接枝物的涂层 聚合物和聚合物/细胞复合材料将在体外进行研究 并在犬动脉移植模型中进行体内移植。的最终关注点 这项提议是开发可生物降解的聚合物，并可以 用于支持细胞生长和广泛的细胞外沉积 血管组织从头合成的基质材料。人口 血管细胞(血管内皮细胞和平滑肌细胞)的 以悬浮液的形式引入聚合物环境 水凝胶的交联性。将使用细胞基因工程 优化其生产的基质材料，以形成 具有机械完整性的组织结构，并引入抗 对新形成的组织具有血栓特性。该提案旨在 发展血管组织移植的基础上提供一个 可生物降解的结构，将用作临时支架和 这将促进细胞增殖和细胞外基质 阐述正常和基因增强的细胞群体。

The goal of this proposal is the development of polymeric scaffolds for cardiovascular tissue engineering which will lead to the production of tissue-based small diameter vascular grafts. Hydrogel polymer scaffolds will be formed by rapid photopolymerization of aqueous precursors which allows for the incorporation of cell suspensions within the final product. Cell viability is maintained during this process, and the focus will be on the use of genetically engineered smooth muscle and endothelial cells. The incorporation of a variety of bioactive domains within the structure of the hydrogel matrices will be investigated to promote cell adhesion, growth, and extracellular matrix synthesis. Bioactive domains to be incorporated will include cell adhesion peptides and peptide growth factors. Cells will be transduced with genes that encode NO synthase for NO production (a proven anti-thrombotic agent), an endothelial cell-specific growth factor (VEGF), lysyl oxidase to enhance matrix crosslinking, and protease inhibitors (TIMPs) to reduce matrix degradation. In vitro assessment of cell viability and proliferation, extracellular matrix synthesis, and transgene expression will be performed under conditions of flow and static culture. Polymer preparations and polymer/cell composites will be tested using small animal in vivo vascular injury models for the recruitment of endothelial cells and the maintenance of homeostasis. Coating of Dacron grafts with polymers and polymer/cell composites will be investigated both in vitro and in vivo in canine arteriograft modalities. The ultimate focus of this proposal is to develop polymers which are biodegradable and can be used to support cell growth and deposition of extensive extracellular matrix material for de novo synthesis of vascular tissue. Populations of vascular cells (smooth muscle and endothelial cells) will be introduced as suspensions to the polymer environment prior to crosslinking of the hydrogel. Genetic engineering of cells will be used to optimize their production of matrix materials for the formation of tissue structures with mechanical integrity and to introduce anti- thrombotic properties to the newly formed tissue. The proposal seeks to develop vascular tissue grafts based on the provision of a biodegradable structure which will serve as a temporary scaffold and which will promote the proliferation and extracellular matrix elaboration of normal and genetically enhanced cell populations.