Since collagen is one of the major extracellular matrix components in vascular tissues, its use for vascular tissue engineering has several advantages. However, collagen extraction and processing for tissue engineering application alters its structure. As a result, collagen-based vascular constructs show poor mechanical properties compared to native tissues. In this work, multi-layer (single, double, and triple) vascular tissue constructs were engineered from porcine smooth muscle cells (PSMCs) entrapped in collagen gel by concentrically and sequentially layering after compaction of the previous layer(s). The engineered tissues were matured for either 14 or 21 days to allow the collagen gel to remodel before viscoelasticity, compliance, histological, and protein expression studies were conducted. While there was no significant difference upon addition of the different layers on the elastic modulus (p > .05), the viscous modulus of the single layer construct was significantly lower than the double and triple layer constructs (p < .05). Increasing the number of layers of the cellularized collagen construct increased the wall thickness and the viscous modulus of the construct. Furthermore, the cellularized single-layer construct had a relatively high compliance, but the double and triple layer constructs had compliance values comparable to both engineered vessels and native vessels. PSMCs were uniformly distributed throughout the cross-section and expressed the anticipated marker proteins smooth muscle-α actin, calponin, and smooth muscle myosin heavy chain. Taken together, this study demonstrated the viscoelastic responsiveness of multi-layer collagen-gel based vascular tissues.

由于胶原蛋白是血管组织中主要的细胞外基质成分之一，因此其在血管组织工程中的应用具有多个优点。但是，用于组织工程应用的胶原蛋白提取和加工会改变其结构。结果，与天然组织相比，基于胶原的血管构造显示出较差的机械性能。在这项工作中，多层血管（单层，双层和三层）的血管组织构建体是由包裹在胶原蛋白凝胶中的猪平滑肌细胞（PSMC）通过在前一层的压实之后同心并依次分层而改造而成的。在进行粘弹性，顺应性，组织学和蛋白质表达研究之前，使工程化的组织成熟14或21天，以使胶原蛋白凝胶重塑。虽然在弹性模量上添加不同的层没有显着差异（p> .05），但单层构造的粘弹性模量显着低于双层和三层构造（p <.05）。增加细胞化的胶原构建体的层数会增加该构建体的壁厚和粘弹性模量。此外，细胞化的单层构建体具有相对较高的顺应性，但是双层和三层构建体具有与工程化容器和天然容器相当的适应性值。PSMC在整个横截面上均匀分布，并表达预期的标志物蛋白平滑肌-α肌动蛋白，钙蛋白和平滑肌肌球蛋白重链。在一起