An Asymmetric Bacterial Cellulose Membrane Incorporating CuPt Nanozymes and Curcumin for Accelerating Wound Healing

Damaged skin compromises its ability to effectively prevent the invasion of harmful bacteria into the tissue, leading to bacterial infection of the wound and hindering the healing process. To address this challenge, we have developed a multifunctional asymmetric wound dressing (CuPt-Cur-ABC) that effectively addresses the lack of bactericidal activity and the release of active ingredients in conventional bacterial cellulose (BC), which can be employed to create a barrier of defense between the wound and its surrounding environment. Compared with BC, asymmetric bacterial cellulose (ABC) used starch as a pore-causing agent, forming holes of different sizes at the top and bottom, which enhanced the ability of ABC to load and moderate-release drugs. First, as-synthesized CuPt nanozymes with an octopod nanoframe structure had multiple enzymatic activities including peroxidase-like, catalase-like, and glutathione peroxidase-like activities. Then, CuPt and curcumin (Cur) were loaded into ABC under ultrasound. Under 808 nm laser irradiation, the nanocomposites possessed good photothermal properties. So the photothermal therapy combined with chemodynamic therapy and inherent antibacterial performance of Cur achieved 99.3% and 99.6% in vitro bactericidal efficacy against Staphylococcus aureus and Escherichia coli, respectively. Moderate release of Cur can clear the excess reactive oxygen species and promote the polarization of macrophages toward the M2 type. In vivo experiments additionally confirmed that the constructed wound dressing achieved multiple functions, including effective antibacterial activity, reversing the inflammatory microenvironment, and promoting wound healing.