Porous photothermal antibacterial antioxidant dual – crosslinked cryogel based on hyaluronic acid/ polydopamine for non-compressible hemostasis and infectious wound repair

Cryogel dressings with good absorption ability and photothermal antibacterial properties for preventing wound infections and treating infected wounds have attracted widespread attention. In this work, a series of cryogels with macroporous structure, antioxidant and photothermal properties were prepared based on adipic dihydrazide modified hyaluronic acid (HA-ADH), and dopamine (DA). The antioxidant properties, hemostatic properties, near infrared (NIR) assisted photothermal antibacterial ability provided by polydopamine, recyclable compression mechanical properties, and cytocompatibility were tested. The results demonstrated that the HA-ADH/DA cryogels have stable mechanical properties, great antibacterial properties against E. coli (EC) and methicillin-resistant S. aureus (MRSA). The high swelling ratio due to the high water retention of HA equipped the cryogels with the capability of absorbing exuded blood and excessive tissue fluid in the infected full-thickness skin defect model of mouse. The cryogels demonstrated good cytocompatibility and antioxidant performance through cell tests and 1, 1-diphenyl-2-methylbenzohydrazino (DPPH) scavenging efficiency test. The cryogels showed enhanced blood-clotting index (BCI) and better hemostatic ability in the mouse liver trauma model and the rat deep non-compressible liver defect model compared with gauze and gelatin sponge. Furthermore, compared with commercial Tegaderm^TM dressing in vivo, the HA-ADH/DA cryogels could greatly promote infected skin wound healing in a full-thickness infected skin defect wound model. In summary, the macroporous HA-ADH/DA cryogels with good antioxidant, high swelling ratio, photothermal antibacterial property, and biocompatibility are a promising hemostatic material and wound healing dressing.