Preparation of injectable free-HRP-mediated and self-catalyzed gelatin-tyramine hydrogel for biomedical applications

Approaches of synthesizing injectable hydrogels have drawn significant attention in several fields including drug delivery, tissue adhesion, and wound healing. Among them, injectable horseradish peroxidase-mediated hydrogels have emerged as a prospective candidate in the development of biomedical materials. In the study, we prepared a hematin-gelatin-tyramine (HGT) polymer which could be exploited to prepare an injectable hydrogel in absence of Horseradish peroxidase (HRP). The chemical structure of HGT was characterized by UV-Vis, H-1-NMR spectroscopies. The HGT hydrogel could be formed in situ rapidly in presence of a small amount of H2O2 (3-15 mM). Besides, HGT can catalyze pyrogallol and guaiacol like the enzyme HRP, and HGT has good biodegradability. Further studies on the biocompatibility of hydrogels will be investigated towards tissue regeneration.