A dual-crosslinked gelatin hydrogel via Dopa-Fe3+ complexation and Fenton reaction was developed as a hydrogel fabrication method to prepare dual-crosslinked hydrogels for biomedical application. To prepare the dual-crosslinked hydrogels in PBS (pH 7.4), the acryl moieties at the gelatin conjugate were firstly crosslinked via Fenton reaction and created Fe3+ ions as a byproduct. These Fe3+ ions used to form Dopa-Fe3+ complexations as a second crosslinking. The hydrogel was formed rapidly using hydrogen peroxide (H2O2) and Iron(Ⅱ) chloride (FeCl2). The mechanical properties could be controlled by varying the H2O2 concentration. The mechanical strength measurement results clearly showed that the methacrylated gelatin dopamine (GMD) hydrogels exhibited 2 or 4 times higher storage moduli compared to the methacrylated gelatin (GMA) or gelatin dopamine (GDA) hydrogels due to dual crosslinking. This hydrogel may be applied as a variety of tissue sealants because of its adhesion that dopamine moieties induce. This newly developed GMD hydrogels don’t use oxidizing agents in mild condition and have great potential for use as injectable materials in tissue regenerative medicine and various biomedical applications.
