The mechanics of host cell repopulation of engineered tissues

项目摘要/摘要 我们建议确定血液动力学环境如何调节依附， 宿主细胞向“现成”脱细胞组织工程化的侵袭和分化 心脏瓣膜(TEHs)。我们假设动态机械拉伸和流体剪应力 通过增强和排列3D基质黏附和排列来调节TEHV基质的重新填充 激活基质中潜在的转化生长因子-β。为了验证我们的假设，生物聚合物支架被植入 成纤维细胞将被浇铸在可伸展的孔和微流体室中，直到被改造成 各向同性或排列的新生组织，然后原位脱细胞。然后我们将量化其程度 血管和循环细胞在循环拉伸下附着和侵袭基质(目的 1)和与体内植入相关的动态流动条件(目标2)。细胞附着， 侵袭、增殖、凋亡、表型和内皮细胞向间充质细胞转化 随着时间的推移，将对标记物进行定量监测。转化生长因子-β激活与3D基质黏附 将检查蛋白质含量和比对，以及相关的信号转导途径 将被询问以确定管理细胞反应的机制。结果是 将对TEHV的发展产生直接影响 有助于(或阻碍)宿主细胞重新填充瓣膜基质的信号，目的是优化 复杂活体条件下自适应重塑的瓣膜设计。

Project Summary/Abstract We propose to determine how the hemodynamic environment regulates the attachment, invasion, and differentiation of host cells into “off-the-shelf” decellularized tissue engineered heart valves (TEHVs). We hypothesize that dynamic mechanical stretch and fluid shear stress regulate repopulation of the TEHV matrix by enhancing and aligning 3D matrix adhesions and activating latent TGF-beta from the matrix. To test our hypothesis, biopolymer scaffolds seeded with fibroblasts will be cast in stretchable wells and microfluidic chambers until remodeled into isotropic or aligned neo-tissues and then decellularized in situ. We will then quantify the extent to which vascular and circulating cells adhere to and invade the matrix under cyclic stretch (Aim 1) and dynamic flow conditions (Aim 2) relevant to in vivo implantation. Cell attachment, infiltration, proliferation, apoptosis, phenotype, and endothelial-to-mesenchymal transition markers will be quantitatively monitored over time. TGF-beta activation and 3D matrix adhesion protein content and alignment will be examined, and associated signal transduction pathways will be interrogated to determine the mechanisms governing the cell responses. The results from this systematic study will have a direct impact on TEHV development by determining the signals that aid (or hinder) host cell repopulation of the valve matrix with the goal of optimizing valve design for adaptive remodeling under complex in vivo conditions.