Rapid Sterilization and Accelerated Wound Healing Using Zn²⁺ and Graphene Oxide Modified g-C₃N₄ under Dual Light Irradiation

Wound healing is affected by bacterial infection and related inflammation, cell proliferation and differentiation, and tissue remodeling. Current antibiotics therapy cannot promote wound healing and kill bacteria at the same time. Herein, hybrid nanosheets of g-C₃N₄-Zn²⁺@graphene oxide (SCN-Zn²⁺@GO) are prepared by combining Zn²⁺ doped sheet-like g-C₃N₄ with graphene oxide via electrostatic bonding and π–π stacking interactions to assist wound healing and kill bacteria simultaneously by short-time exposure to 660 and 808 nm light. The gene expressions of matrix metalloproteinase-2, type I collagen, type III collagen, and interleukin β in fibroblasts are regulated by GO and released Zn²⁺, which can accelerate wound healing. Co-irradiation produces an antibacterial ratio over 99.1% within a short time because of the synergistic effects of both photodynamic antibacterial and photothermal antibacterial treatments. The hyperthermia produced by 808 nm light illumination can weaken the bacterial activity. And these bacteria can be easily killed by membrane destruction, protein denaturation, and disruption of bacterial metabolic pathways due to reactive oxygen species produced under 660 nm light irradiation. This strategy of Zn²⁺ and GO modification can increase the antibacterial efficacy of SCN and accelerate wound healing at the same time, which makes this SCN-Zn²⁺@GO be very promising in bacteria-infected wound healing therapy.