Mechanically Robust Gelatin–Alginate IPN Hydrogels by a Combination of Enzymatic and Ionic Crosslinking Approaches

In this report, novel biopolymer hydrogels composed of gelatin and alginate with an interpenetrating polymer network (IPN) structure were prepared by a combination of enzymatic and ionic crosslinking approaches. The gelation processes of the IPN hydrogels were monitored using rheological techniques. The data confirmed the formation of dual networks: one gelatin network crosslinked by transglutaminase (TG) and another alginate network crosslinked by calcium ions. The results of mechanical testing revealed that the tensile and compressive strength of the hydrogels crosslinked in the presence of both TG and calcium ions were significantly improved. Preliminary studies have also shown that the hydrogels can support cell adhesion and spreading. These mechanically robust biopolymer hydrogels prepared by such biocompatible approaches are promising for the development of tissue engineering scaffolds.