Bioinspired Multifunctional Cellulose Nanofibril-Based In Situ Liquid Wound Dressing for Multiple Synergistic Therapy of the Postoperative Infected Wound

A smart in situ-formed wound dressing with excellent antibacterial ability against drug-resistance bacterial, antitumor, and biofilm-eliminating activities to promote effective wound closure is highly desirable in therapeutic and clinical applications. Herein, we designed and developed a multifunctional; shape-adaptable; and pH, temperature, and near-infrared radiation (NIR) multiple responsive cellulose nanofibril (CNF)-based in situ liquid wound dressing, using a pH-sensitive CNF grafted with terminated amino hyperbranched polyamines (HBP-NH₂) as a substrate, along with poly(N-isopropylacrylamide) and indocyanine green (ICG) loaded as the temperature and NIR on/off switches, respectively. The 3D nanocage network structure of CNF and the nanocavities in the hyperbranched structure of HBP-NH₂ endow the dressing with a high loading capacity for active drugs (doxorubicin and ICG) simultaneously. Moreover, the responsiveness of the dressing to multiple stimuli enables controllable and efficient drug release to the wound area. The bioinspired dressing demonstrates excellent antibacterial activity against common bacteria and methicillin-resistant Staphylococcus aureus, antitumor activity against A375 tumor cells, and biofilm-eliminating capability. In addition, the developed dressing synergistically combines multiple therapeutic strategies for effective wound healing, specifically photothermal therapy, photodynamic therapy, and chemotherapy. The design provides an ideal clinical intervention strategy for irregular tumor postoperative infected wounds.