Albumin-based dynamic double cross-linked hydrogel with self-healing property for antimicrobial application

• Bovine serum albumin based hydrogel via double dynamic crosslinking is prepared. • Tetrakis (hydroxymethyl) phosphonium sulfate enables gel formation. • Tetrakis (hydroxymethyl) phosphonium sulfate also endows antimicrobial properties. • The hydrogel featuring elasticity, mechanical strength and self-healing properties. • The hydrogel has excellent bacteriostatic ability and low cytotoxicity. Hydrogels as ideal material are widely used in biomedical field against bacterial infection. Hydrogels synthesized from natural protein possess better biocompatibility than that synthesized from synthetic polymers. In this work, we designed bovine serum albumin (BSA) based hydrogel via double dynamic crosslinking. The cleavage and rearrangement of disulfide bonds of BSA triggered by glutathione (GSH) forms a disulfide bridge network, and tetrakis (hydroxymethyl) phosphonium sulfate (THPS) grafts the amino groups of BSA by a Mannich-type reaction to form a second network. Integrating THPS into the BSA/GSH system enables gel formation and endows excellent antimicrobial properties. Rheological tests showed the hydrogel featuring elasticity, good mechanical strength and self-healing properties. Antibacterial and cytotoxicity tests proved the hydrogel excellent bacteriostatic ability and low cytotoxicity. This albumin-based hydrogel with low cost is expected to realize wide biomedical applications.