Injectable and photothermal antibacterial bacterial cellulose cryogel for rapid hemostasis and repair of irregular and deep skin wounds

For irregular and deep skin wounds, it's difficult for wound dressing to reach the injured site to achieve rapid hemostasis and provide wound protection. Bacterial cellulose (BC) has high strength and natural threedimensional pore structure, which endows it shape recovery ability after absorbing blood when injected to the wound. Therefore, in the study, an injectable aldehyde bacterial cellulose/polydopamine (DBC/PDA) photothermal cryogel was prepared by oxidation polymerization method for hemostasis and repair of irregular and deep skin wounds. BC was oxidized by NaIO4 to form DBC and dopamine (DA) was introduced into DBC by reacting with the aldehyde group in DBC through Schiff base reaction. Under oxidation effect of NaIO4 and with freezing condition, water crystallization led to local aggregation of DA and DBC, and at the same time DA was oxidized to PDA and polymerized with DA on DBC. After the melting process, the porous cryogel was obtained. The introduction of PDA enhances the photothermal properties of DBC/PDA cryogel. DBC/PDA cryogel can kill most bacteria and provide wound protection under near-infrared light. In vitro and in vivo hemostatic tests show that the DBC/PDA cryogel can quickly absorb blood and stop bleeding. Combined with its good injectable, DBC/ PDA cryogel can provide rapid hemostatic and protection in the face of irregular and deep skin wounds.