3D-Printed Hydrogel Patches Embedded with Cu-Modified Liquid Metal Nanoparticles for Accelerated Wound Healing.

Wound healing is significantly challenged by resistant bacterial infections. Gallium-based liquid metal (LM) antibacterial agents show promise due to their non-inducement of resistance, though their efficacy remains limited. Here, we graft copper onto nano-LM surfaces via ultrasonication to create copper-modified LM nanoparticles (Cu-LMNPs) with enhanced antibacterial properties. Specific experiments suggest that Cu-LMNPs enhance antibacterial efficacy against ampicillin-resistant Escherichia coli (E. coli) and methicillin-resistant Staphylococcus aureus (MRSA) in vitro, achieving ≈100% antibacterial effectiveness. The remarkable antibacterial efficacy stems from the considerable increase in Cu2⁺ and Ga3⁺ concentrations. Further, the Cu-LMNPs and epidermal growth factors (EGF) are incorporated into the rheology-tunable hydrogels with excellent printability and biocompatibility for accelerating chronically infected wound healing. In vivo experiments demonstrate that the hydrogel patches effectively treated MRSA-infected wounds in mice. Sustained release of multiple ions and EGF promotes epithelial regeneration, collagen deposition, and neovascularization, making the wound markedly distinct from the control group and nearly fully healed within 10 days. Overall, this research presents a novel 3D-printed mesh hydrogel patch that not only combats bacterial infections but also accelerates wound healing.