Enzymatically Prepared Dual Functionalized Hydrogels with Gelatin and Heparin To Facilitate Cellular Attachment and Proliferation.

Biologically active artificial scaffolds for cell seeding are developed by mimicking extracellular matrices using synthetic materials. Here, we propose a feasible approach employing biocatalysis to integrate natural components, that is, gelatin and heparin, into a synthetic scaffold, namely a polyethylene glycol (PEG)-based hydrogel. Initiation of horseradish peroxidase-mediated redox reaction enabled both hydrogel formation of tetra-thiolated PEG via disulfide linkage and incorporation of chemically thiolated gelatin (Gela-SH) and heparin (Hepa-SH) into the polymeric network. We found that the compatibility of the type of gelatin with heparin was crucial for the hydrogelation process. Alkaline-treated gelatin exhibited superior performance over acid-treated gelatin to generate dual functionality in the resultant hydrogel originating from the two natural biopolymers. The Gela-SH/Hepa-SH dual functionalized PEG-based hydrogel supported both cellular attachment and binding of basic fibroblast growth factor (bFGF) under cell culture conditions, which increased the proliferation and phenotype transformation of NIH3T3 cells cultured on the hydrogel. Inclusion of bFGF and a commercial growth factor cocktail in hydrogel matrices effectively enhanced cell spreading and confluency of both NIH3T3 cells and HUVECs, respectively, suggesting a potential method to design artificial scaffolds containing active growth factors.