Bacitracin-Loaded Type I Collagen/Bacterial Cellulose Dressing for the Repair of Infected Wounds

In this study, bacitracin-a small-molecule antibacterial agent-was incorporated into the network structure of a type I collagen/bacterial cellulose (Col/BC) composite via in situ recombination and impregnation adsorption, leveraging the well-established drug-loading capacity and sustained-release characteristics of type I collagen. The obtained BA@Col/BC (BA@CBC) functional dressing features a well-defined nanoporous architecture, high porosity (83.9 ± 1.8%), rapid water absorption kinetics, substantial water absorption capacity (48.7 ± 2.4 g/g), and satisfactory moisture permeability (2984 ± 56 g·m²·day). Critically, the introduction of type I collagen not only effectively delays the release of bacitracin, but also significantly improves the cytocompatibility of the bacterial cellulose-based dressing. BA@CBC exhibits powerful antibacterial activities against S. aureus and MRSA, and can promote the proliferation of NIH3T3 and HUVEC, demonstrating excellent cytocompatibility. In vivo studies in a murine infected-wound model revealed that BA@CBC significantly accelerates wound closure compared to controls; histological evaluation further showed the most organized re-epithelialization, robust granulation tissue formation, and de novo hair follicle regeneration in the BA@CBC group. Fluorescence immunohistochemical analysis confirmed markedly reduced expression of pro-inflammatory cytokines IL-1β and TNF-α in BA@CBC-treated wounds, indicating effective suppression of excessive inflammation and consequent improvement of the wound microenvironment. Collectively, BA@CBC integrates favorable physicochemical properties, sustained antibacterial functionality, and superior cytocompatibility-positioning it as a promising candidate for clinical management of infected wounds.