Vascularization of polymeric tissue beds

聚合物组织床的血管化

• 批准号: 7828505
• 负责人: ROGER E MARCHANT
• 金额: $ 50万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7828505
• 关键词: Address; Affinity; Angiogenic Factor; Area; Beds; Biodegradation; Bioluminescence; Blood Vessels; Cardiac; Cell Differentiation process; Cell Line; Cell-Matrix Junction; Cells; Clinical; Cytokine Signaling; Data; Endothelial Cells; Engineering; Excision; Firefly Luciferases; Foundations; Frequencies; Goals; Health; Hemostatic function; Histology; Homing; Human; Hydrogels; Image; Imaging Techniques; Implant; In Vitro; Inflammatory; Integrin Binding; Integrins; Interstitial Collagenase; Kinetics; Ligands; Liver; Measures; Mediating; Modeling; Molecular Weight; Monitor; Mus; Nutrient; Organ; Oxygen; Peptides; Polymers; Positron-Emission Tomography; RGD (sequence); Recruitment Activity; Regenerative Medicine; Reporter; Research; Site; Specificity; Testing; Thromboplastin; Thymidine Kinase; Tissue Engineering; Tissues; Translations; VWF gene; Vascular Cell Adhesion Molecule-1; Vascular Endothelial Growth Factors; Vascularization; Waste Products; Western Blotting; acetyl-LDL; angiogenesis; base; cadherin 5; cellular engineering; clinical application; collagenase; controlled release; density; design; embryonic stem cell; improved; in vivo; insight; limb bone; matrigel; migration; mimetics; mouse model; nanoparticle; overexpression; progenitor; public health relevance; reconstruction; red fluorescent protein; response; scaffold; subcutaneous; uptake; vasculogenesis

DESCRIPTION (provided by applicant): This proposal, entitled Vascularization of Polymeric Tissue Beds, seeks to address the broad Challenge Area of (11) Regenerative Medicine, and the specific Challenge Topic of vascular networks in engineered tissues: 11-EB-101. The major impediment to progress in the field of tissue engineering and regenerative medicine is the lack of effective vascularization in tissue-engineered constructs capable of timely delivery of oxygen and nutrients, and removal of waste products. To address this major challenge, the proposed research seeks to elucidate mechanisms that direct vasculogenesis and angiogenesis by using a cellular platform that can probe the material parameters, and a modular synthetic platform that can be tuned to enhance vasculogenesis. The overall goal is to create a prevascularlized tissue bed by tuning a cellular platform to enhance homing and remodeling, and a polymeric platform that is conducive for vasculogenesis. The central hypothesis is that a tissue engineered construct conducive to vascularization requires the capacity 1) to provide endothelial cell specific attachment, 2) for local tissue remodeling, and 3) to recruit endothelial cells through cytokine signaling. To investigate this hypothesis, we propose four specific Aims: (1) to engineer cellular attachment and matrix remodeling functions into embryonic stem cell derived endothelial cells. We plan to overexpress alpha-V and beta-3, (¿v¿3) or alpha-5 and beta-1 (¿5¿1) integrins, to enhance the cell's capacity for attachment in an ECM-mimetic polymer network, and overexpress MMP1 to enhance the cell's capacity for tissue remodeling. (2) To engineer a PEG-based ECM-mimetic hydrogel, which incorporates integrin binding peptides (-RGD- or -CRRETAWAC- which has high affinity and selectivity for ¿v¿3 and ¿5¿1) for cell attachment; a collagenase-sensitive peptide -GPQGIAGQ- for EC mediated biodegradation, and entrapped nanoparticles that provide a reservoir for controlled release of angiogenic factors (VEGF). (3) To integrate and tune the cellular and polymeric platforms, to achieve optimal vasculogenic and angiogenic responses, as determined by vessel counts and 3D vessel reconstruction. Clones expressing varying levels of ¿v¿3 and ¿5¿1 integrins will be tested with ECM-mimetic hydrogels with a range of peptide ligand density. Clones expressing varying levels of MMP1 will be tested with hydrogels varying in PEG molecular weight. The effect of VEGF secretion will be evaluated by quantitative measures of EC progenitor migration. (4) To evaluate prevascularization of the cellular and polymeric platforms in vivo, optimized scaffolds will be implanted into a mouse subcutaneous model of vascularization and compared with Matrigel positive controls, and monitored by in vivo imaging techniques (bioluminescence and PET). Successful completion of this research will generate fundamental insights into the requirements needed for developing vascular networks in engineered tissue constructs and lay a basic foundation for facilitating clinical translation into engineered tissues. PUBLIC HEALTH RELEVANCE: Tissue engineering is an approach that seeks to augment or replace the function of failing organs, and offers the potential for major beneficial impact on human health. However, the major impediment to progress in this field is the lack of effective vascularization of the tissue-engineered constructs capable of timely delivery of oxygen and nutrients and removal of waste products. To address this major challenge, the proposed research seeks to evaluate the mechanisms that direct angiogenesis in parallel with using a cellular platform that can probe the material parameters, and a modular synthetic platform that can be tuned to improve vasculogenesis. Successful completion of the research will generate fundamental insights into the requirements needed for developing vascular networks in engineered tissue constructs and facilitate translation into clinical applications.

描述（由申请人提供）：本提案题为“聚合物组织床的血管化”，旨在解决（11）再生医学的广泛挑战领域和工程组织中血管网络的特定挑战主题：11-EB-101。组织工程和再生医学领域进展的主要障碍是组织工程构建物中缺乏能够及时递送氧气和营养物以及去除废物的有效血管化。为了解决这一重大挑战，拟议的研究旨在通过使用可以探测材料参数的细胞平台和可以调整以增强血管发生的模块化合成平台来阐明指导血管发生和血管生成的机制。总体目标是通过调整细胞平台以增强归巢和重塑，以及有助于血管发生的聚合物平台来创建预血管化组织床。中心假设是，有助于血管化的组织工程化构建体需要以下能力：1）提供内皮细胞特异性附着，2）局部组织重塑，和3）通过细胞因子信号传导募集内皮细胞。为了验证这一假说，我们提出了四个具体的目标：（1）将细胞粘附和基质重塑功能工程化到胚胎干细胞衍生的内皮细胞中。我们计划过表达α-V和β-3（<$v <$3）或α-5和β-1（<$5 <$1）整合素，以增强细胞在ECM模拟聚合物网络中的附着能力，并过表达MMP 1以增强细胞的组织重塑能力。(2)设计一种基于PEG的ECM模拟水凝胶，其中包含整合素结合肽（-RGD-或-CRRETAWAC-对µ v µ 3和µ 5 µ 1具有高亲和力和选择性）用于细胞附着;胶原酶敏感肽-GPQGIAGQ-用于EC介导的生物降解，以及为血管生成因子（VEGF）的受控释放提供储存库的包埋纳米颗粒。(3)整合和调整细胞和聚合物平台，以实现最佳血管生成和血管生成反应，如血管计数和3D血管重建所确定。表达不同水平的<$v <$3和<$5 <$1整联蛋白的克隆将用具有一系列肽配体密度的ECM模拟水凝胶进行测试。表达不同水平MMP 1的克隆将用PEG分子量不同的水凝胶进行测试。VEGF分泌的作用将通过EC祖细胞迁移的定量测量来评估。(4)为了评价体内细胞和聚合物平台的预血管化，将优化的支架植入血管化的小鼠皮下模型中，并与Matrigel阳性对照进行比较，并通过体内成像技术（生物发光和PET）进行监测。这项研究的成功完成将产生对在工程组织构建中开发血管网络所需要求的基本见解，并为促进临床转化为工程组织奠定基础。 公共卫生关系：组织工程是一种寻求增强或替代衰竭器官功能的方法，并为人类健康提供了重大有益影响的潜力。然而，该领域进展的主要障碍是缺乏能够及时输送氧气和营养物并去除废物的组织工程化结构的有效血管化。为了解决这一重大挑战，拟议的研究旨在评估指导血管生成的机制，同时使用可以探测材料参数的细胞平台和可以调整以改善血管生成的模块化合成平台。研究的成功完成将产生对在工程组织构建中开发血管网络所需要求的基本见解，并促进转化为临床应用。