An In Vitro Model of Biomimetic Vascular Cell Spatial Arrangement Based on Fiber-Reinforced Biocomposite

In vitro construction of bionic vascular models plays a pivotal role in the research of vascular diseases and drug screening. The existing vascular models in vitro have limitations in terms of the insufficient spatial arrangement of vascular cells to achieve functionalization. In this study, a cell adhesion-scaffold composite system assisted by degradable gelatin-based hydrogel was proposed to realize the implantation of vascular cells in the tubular space structure. A bilayer vascular tissue model was constructed in vitro, in which Smooth muscle cells (SMCs) were arranged in a circumferential direction, and Endothelial cells (ECs) were uniformly and continuously distributed along the inner wall of the SMC. Melt electrowriting was used to print a polycaprolactone high-precision tubular scaffold, which provided mechanical support while effectively guiding the circumferential arrangement of SMCs and high-density spatial planting. By comparing SMCs cultured on two-dimensional (2D) disoriented fibers, three-dimensional (3D) disoriented fibers, and 3D circumferential fibers, the expression of α-smooth muscle actin (α-SMA) was significantly enhanced in cells cultured on 3D oriented fibers, and the expression of contraction-related genes increased by about 2.5 times compared with those cultured on 2D disoriented fibers. ECs were seeded onto the inner surface of the SMC layer, resulting in the spatial construction of the two vascular cell types. The bilayer vascular tissue cell model constructed by this method provides an approach for the screening and evaluation of vascular-related drugs in vitro.