Innovative In Vivo-like Model for Vascular Tissue Engineering

血管组织工程的创新类体内模型

• 批准号: 8135937
• 负责人: JOERG C. GERLACH
• 金额: $ 50.54万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2015-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8135937
• 关键词: Address; Angioblast; Basic Science; Biological Models; Biomedical Engineering; Bioreactors; Blood Vessels; Bone Marrow Stem Cell; Calcium; Cell Density; Cell model; Cells; Cellular biology; Coculture Techniques; Cues; Development; Discontinuous Capillary; Engineering; Environment; Experimental Models; Fetal Liver; Fiber; Flow Cytometry; Fluorescence; Gases; Gene Expression; Generations; Genes; Harvest; Heart Rate; Heating; Hematology; Hematopoietic; Hematopoietic stem cells; Hepatic; Hepatic Tissue; Hepatocyte; Hepatology; High temperature of physical object; Histology; Human; Hydroxyapatites; In Vitro; Label; Laboratories; Liver; Mechanics; Mediator of activation protein; Modeling; Molecular Biology; Organ; Organ Transplantation; Organogenesis; Outcome; Pathway interactions; Perfusion; Play; Principal Investigator; Proteins; Public Health; Research; Role; Science; Second Pregnancy Trimester; Stem cells; Structure; Systems Analysis; Technology; Testing; Time; Tissue Engineering; Tissue Harvesting; Tissues; Transfection; Transplantation; Vascularization; abstracting; angiogenesis; base; bone; calcium phosphate; cell type; clinical application; clinically significant; density; design; fetal; hematopoietic tissue; improved; in vitro Model; in vivo; innovation; mortality; physical conditioning; postnatal; prenatal; pressure; progenitor; response; scaffold; shear stress; stem cell niche; success; three-dimensional modeling; tissue culture; transplantation medicine; vascular tissue engineering

DESCRIPTION (provided by applicant): The shortage of donor organs for transplantation suggests a need to develop engineered tissue transplants. Proper in vitro vascularization, a key prerequisite for the development of functional engineered tissue constructs, would enable adequate mass exchange, gas supply, and functional mediator exchange in high- density tissue cultures. The impact of physical and mechanical factors supporting endothelial differentiation has been investigated, but not in three-dimensional (3D) co-culture models. We propose to address this gap in cellular models and technology model systems, by analyzing neo-vascularization in an organ-like environment in vitro designed to mimic human organogenesis and that can vary physical conditions, such as flow- and pressure changes in the rhythm of the heart rate. In the fetal liver in vivo, angiogenesis occurs in hematopoietic and hepatic tissues that develop together. In our cell model for enabling vascularization in vitro, we therefore propose to investigate second trimester human fetal liver derived endothelial progenitors within fetal parenchymal cells, which contribute to hematopoietic and hepatic tissue vascularization. In the culture technology model, we propose to apply physical forces to control vascular structure formation, shear stress, perfusion flow and pressure changes. Additionally we will investigate the effects of calcium liberating hydroxyapatite scaffolds that mimics natural bone on formation of hematopoietic vascular sinusoids in the stem cell niche. RFP transfection labeled progenitors (hemangioblasts and angioblasts) and non-endothelial fetal liver cells will be cultured in 3D perfusion and the response to various physical-mechanical cues determined. Harvested cells will be analyzed by histology, flow cytometry, and gene expression, and compared to prenatal organ explants and postnatal organ tissues in vivo. The prior labeling of hemangioblasts will allow us to selectively distinguish between original hemangioblasts, endothelial- and non-endothelial cell types. The bioreactor model provides four independent interwoven hollow fiber compartments, enabling 3D perfusion with low gradients by decentral mass exchange and integral oxygenation. This has been proven to support vascularized tissue-like structure formation at high cell densities. We have already demonstrated that our 3D perfusion bioreactors support the spontaneous neo-tissue formation with neo-vascular hepatic structures and functionality in the laboratory and in clinical application for extracorporeal liver support. The innovation of our project is the specific experimental model that mimics the mass exchange in the native organ environment, allowing the fate of labeled fetal vascular progenitors to be studied during tissue formation, depending on different physical conditions. The project outcome will contribute to our understanding of the role of bioengineered supports and physical forces in establishing functional 3D engineered neo-vascular constructs in hematopoietic and hepatic tissues. (End of Abstract)

描述(由申请人提供)： 可供移植的供体器官短缺表明有必要开发工程化组织移植。适当的体外血管形成是开发功能工程化组织结构的关键前提，它将在高密度组织培养中实现足够的质量交换、气体供应和功能介质交换。支持内皮细胞分化的物理和机械因素的影响已经被研究，但在三维(3D)共培养模型中还没有。我们建议通过分析体外器官样环境中的新生血管来解决细胞模型和技术模型系统中的这一差距，该环境旨在模拟人类器官发生，并可以改变物理条件，如心率节奏中的流量和压力变化。在活体胎肝中，血管生成发生在共同发育的造血细胞和肝脏组织中。因此，在我们的体外血管形成细胞模型中，我们建议研究胚胎实质细胞中的人胎肝来源内皮祖细胞，这有助于造血和肝组织的血管形成。在培养技术模型中，我们提出应用物理力来控制血管结构的形成、剪应力、灌流流量和压力的变化。此外，我们还将研究模拟自然骨的释放钙的羟基磷灰石支架对干细胞壁龛中造血血管血窦形成的影响。RFP标记的前体细胞(血管母细胞和血管母细胞)和非内皮胎肝细胞将在3D灌流中培养，并测定对各种物理-机械提示的反应。收获的细胞将通过组织学、流式细胞仪和基因表达分析，并与出生前器官外植体和体内出生后器官组织进行比较。血管母细胞的预先标记将使我们能够有选择地区分原始血管母细胞、内皮细胞和非内皮细胞类型。生物反应器模型提供四个相互交织的中空纤维隔室，通过偏心质量交换和整体充氧实现低梯度的3D灌流。这已被证明支持在高细胞密度下形成血管化的组织样结构。我们已经证明，我们的3D灌流生物反应器在实验室和临床应用中支持自发形成具有新生血管的肝脏结构和功能的新组织，用于体外肝脏支持。我们项目的创新是模拟自然器官环境中的质量交换的特定实验模型，允许根据不同的物理条件，研究标记的胎儿血管前体细胞在组织形成过程中的命运。该项目的成果将有助于我们理解生物工程支持和物理力量在在造血和肝脏组织中建立功能性3D工程新血管结构中的作用。(摘要结束)