SMC Differentiation During Vascular Graft Assembly

描述(由申请人提供)： 为了优化组织工程血管移植物的构建和性能，本研究的目的是阐明在培养过程中控制SMC分化和防止SMC去分化的影响因素。首先，我们将研究成熟的SMC在我们的培养系统中的行为。然而，由于从成年患者获得和保持分化的SMC具有潜在的困难，我们还将研究两种类型的SMC前体细胞(胚胎来源的10“1”1/2细胞和成人骨髓来源的间充质细胞)在我们的系统中产生功能性、分化的SMC的潜力，这两种细胞是异体或自体移植的潜在细胞来源。我们假设，通过控制生化和生物力学刺激，试图概括胚胎血管发育过程中所经历的环境，可以最大限度地诱导和/或维持SMC分化，这将导致组织工程血管移植物结构完整性和性能的改善。每个特定目标的目的都是试图概括某些发育条件，并确定这些生化和生物力学刺激对血管组织工程中SMC前体细胞分化和/或SMC表型维持的影响。在每个目标中，首先将在2D培养中进行研究，以在为细胞黏附提供特定配体的表面上表征细胞对转化生长因子-b的反应。随后，细胞将在3D生物活性水凝胶支架中培养，该支架旨在呈现2D研究中确定的生物因素的最佳组合和数量，并确认结果从2D转换到3D。最后，细胞将在脉动流动生物反应器中由生物活性水凝胶支架形成的3D管状结构中培养，以评估机械条件在SMC分化中的作用以及生物化学和生物力学刺激可能的协同效应。将评估成体和胚胎的排泄情况。本课程的研究将针对每种细胞类型进行。

DESCRIPTION (provided by applicant): The goal of this research is to elucidate the influences that control smooth muscle cell (SMC) differentiation and prevent SMC de-differentiation in culture in order to optimize construction and performance of tissue engineered vascular grafts. Initially, we will study the behavior of mature SMCs in our culture systems. However, because of the potential difficulty associated with obtaining and maintaining differentiated SMCs from adult patients, we will also investigate the potential of two types of SMC progenitors (embryonically-derived 10"1"1/2cells and adult marrow-derived mesenchymal cells), which represent potential cell sources for allogeneic or autologous graft creation, to generate functional, differentiated SMCs in our system. We hypothesize that through control of both biochemical and biomechanical stimuli, attempting to recapitulate the environments experienced during embryonic vascular development, induction and/or maintenance of SMC differentiation can be maximized and that this will lead to improved structural integrity and performance of tissue engineered vascular grafts. The goal of each of the specific aims is to attempt to recapitulate certain developmental conditions and to determine the effects of these biochemical and biomechanical stimuli on differentiation of SMC progenitors and/or maintenance of SMC phenotype for vascular tissue engineering. In each of the aims, studies will first be conducted in 2D culture to characterize cellular responses to TGF-b on surfaces that provide defined ligands for cell adhesion. Following this, cells will be cultured in 3D bioactive hydrogel scaffolds designed to present the optimal combination and quantity of biological factors, as determined in the 2D studies, and to confirm the translation of results from 2D to 3D. Finally, cells will be cultured in 3D tubular constructs formed from bioactive, hydrogel scaffolds in a pulsatile flow bioreactor to evaluate the role of mechanical conditioning in SMC differentiation as well as the possible synergistic effects of biochemical and biomechanical stimulation. Adult and embryonic flow conditions will be evaluated. This course of studies will be performed for each cell type.