Fabrication of Hydrogel Tubes with Vascular Mimicked Stiffness for Construction of in Vitro Vascular Models

Stiffness of blood vessels is one of the most important parameters involving in vascular diseases. However, no vascular model well mimics the stiffness of native blood vessels, and thus, the effects of vascular stiffness on endothelial cells cannot be studied in vitro. For this purpose, we fabricated the gelatin/carboxybetaine (CBMA) interpenetrating network (IPN) hydrogel tubes to exactly present the stiffness of soft (i.e., physical) and stiff (i.e., pathological) arteries in human. The vascular models are then constructed via endothelial cell culture inside the gel tubes under a cardiac-like pulsatile perfusion. As found, the velocity magnitude and wall shear stress in the stiff gel tube are much higher than those in the soft one. Correspondingly, the endothelial cells in the soft gel tube (i.e., physical model) express higher vascular functions than those in the stiff one (i.e., pathological model). Moreover, a pathological model was more sensitive to ethanol-induced vascular injury than the physical model. Thus, the new vascular models with a tunable stiffness provide a useful tool to investigate the stiffness involved mechanism in vascular diseases under in vivo mimicked microenvironments.