Dopamine-assisted macroporous collagen nanocomposite hydrogel dressing with antibacterial activity for bacteria-infected cutaneous wound healing.

Bacteria-infected wounds impose a huge health burden on both patients and society. Multifunctional biomass-based hydrogels have attracted considerable research interest as wound dressing materials. However, the fabrication and applications of these hydrogels face challenges due to their poor injectability and limited adhesiveness and antibacterial property. Here, we proposed an effective approach to create hierarchical type I collagen nanocomposite hydrogels exhibiting good anti-oxidation, antibacterial activity, cytocompatibility, and anti-inflammatory properties through combination of Mannich-type reaction and reinforcement of polydopamine-functionalized Laponite clay nanoplatelets to the collagen networks. The results indicated that the clay nanoplatelets were surface-functionalized with polydopamine to serve as biocompatible inorganic crosslinkers to reinforce the collagen networks. Owing to the presence of imine bonds, hydrogen bonds, and electrostatic attractions between the collagen and the clay nanoplatelets, the microstructures of collagen were stabilized. The resultant hierarchical hydrogels demonstrated huge potential in accelerating S. aureus-infected cutaneous wound healing through eradicating the bacteria and eliminating the inflammation of bacteria-infected wounds, resulting in complete wound recovery with 8 days' treatment. We envision that these findings can offer a feasible pathway for rational design and preparation of multifunctional hydrogels that hold great potential for the applications of wound healing.