Biomimetic hydrogels based on natural dextran and gelatin for vascular tissue engineering application

Abstract

Hydrogels are crosslinked polymer networks with high water content. They have the capability to mimic native ECM and thus are highly desirable as 3D scaffolds for cell encapsulation. Synthetic hydrogels for cell encapsulation have hitherto been based on poly(ethylene glycol), which is non-natural, non-biodegradable, and only terminal-functionalizable. Dextran is highly hydrophilic but also biodegradable and pendant-functionalizable. More importantly, it resembles the native glycosaminoglycans.

This study aims to fabricate hydrogels based on natural dextran and gelatin, which could promote 3D SMC spreading and proliferation. Two series of hydrogels were fabricated. The first hydrogel series is based on the interpenetrating polymer network (IPN) of gelatin and dextran bifunctionalized with methacrylate (MA) and aldehyde (AD) (Dex-MA-AD). These IPN hydrogels not only supported endothelial cell (EC) adhesion and spreading on the surface, but also allowed encapsulated SMCs to proliferate and spread in the bulk interior of the hydrogel; however, the Schiff base reaction was not easily controllable and while SMC spreading within the hydrogel did occur, it was rather limited.