Magnetically Responsive Bacterial Cellulose–Fe3O4 Nanocomposite for Medical Dressing of Infected Wounds

Abstract

To address the limitations of conventional wound dressings in the management of bacteria-infected cutaneous wounds, including uncontrolled drug release, insufficient antibacterial activity, and limited wound repair efficacy, a nanoscale bacterial cellulose (BC)-based magnetoresponsive composite dressing was developed in this study. This material was designed for local antibacterial therapy and repair of infected skin wounds, particularly in wound care scenarios requiring externally regulated drug release and sustained tissue regeneration. Using an in situ coprecipitation strategy, Fe3O4 nanoparticles were incorporated into the three-dimensional nanofibrous network of BC to fabricate a BC/Fe3O4 magnetoresponsive nanocomposite film, which was further loaded with quercetin (Que) to obtain a multifunctional smart wound dressing. The nanoscale morphology, structural characteristics, and physicochemical properties of the composite dressing were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), mechanical testing, and magnetic analyses. Its application potential in infected wound management was evaluated through in vitro drug release assays, antibacterial tests against common wound pathogens, and an infected mouse wound model. The results showed that Fe3O4 nanoparticles were successfully distributed within the interconnected BC nanofiber network, forming a magnetically responsive nanocomposite architecture. Under an external magnetic field, the dressing enabled enhanced Que release, indicating its potential for magnetic-field-regulated local drug delivery. The Que-loaded nanocomposite dressing exhibited favorable antibacterial activity against E. coli, Staphylococcus aureus, and Pseudomonas aeruginosa. In vivo experiments further demonstrated that the dressing showed good biocompatibility and effectively promoted infected wound closure. Under magnetic field stimulation, the wound healing rate exceeded 98%. Overall, this BC/Fe3O4-Que nanocomposite dressing integrates nanoscale structural advantages, magnetic-field-regulated drug release, antibacterial activity, and wound-healing promotion, making it particularly suitable for the local treatment of bacteria-infected cutaneous wounds.