DEGRADABLE SCAFFOLDS FOR GENETICALLY ENGINEERED GRAFTS

该提案的目标是开发聚合物支架， 心血管组织工程，这将导致生产 基于组织的小直径血管移植物。水凝胶聚合物支架 将通过含水前体的快速光聚合形成， 允许将细胞悬浮液掺入到最终的 产品 在此过程中维持细胞活力， 重点将放在基因工程平滑肌的使用， 内皮细胞 多种生物活性域的掺入 在水凝胶基质的结构内， 促进细胞粘附、生长和细胞外基质合成。 待并入的生物活性结构域将包括细胞粘附肽 和肽生长因子。 细胞将被基因转导， 编码NO合成酶以产生NO（一种经证实的抗血栓形成剂）， 内皮细胞特异性生长因子（VEGF）、赖氨酰氧化酶， 增强基质交联，和蛋白酶抑制剂（TIMP），以减少 基质降解 体外评估细胞活力和 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。 聚合物 制备和聚合物/电池复合材料将测试使用小 用于募集内皮细胞的动物体内血管损伤模型 细胞和维持体内平衡。 涤纶移植物的涂层 聚合物和聚合物/细胞复合材料将在体外进行研究 以及在犬动脉移植物形态中的体内。 终极焦点 该建议是开发可生物降解的聚合物， 用于支持细胞生长和广泛的细胞外沉积 用于从头合成维管组织的基质材料。 人口 血管细胞（平滑肌细胞和内皮细胞）将 作为悬浮液引入到聚合物环境中， 水凝胶的交联。细胞的基因工程将被用于 以优化其基质材料的生产， 组织结构的机械完整性，并引入抗 血栓性质的新形成的组织。 该提案寻求 开发血管组织移植物， 可生物降解的结构，其将用作临时支架， 这将促进增殖和细胞外基质 正常和遗传增强的细胞群体的精心制作。

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.