Development of a Drug Delivery System with Bacterial Cellulose and Gelatin: Physicochemical and Microbiological Evaluation

The growing threat of antimicrobial resistance drives the need for innovative and multifunctional therapeutic systems. In this study, a controlled-release system based on a bioactive film composed of gelatin, bacterial cellulose (BC), sericin, citric acid, PEG 400, and nisin was developed for topical applications in infected wound treatment. BC membranes were produced using Komagataeibacter xylinus and enzymatically treated to optimize dispersion within the polymer matrix. The resulting system exhibited a semi-rigid, homogeneous morphology with appropriate visual characteristics for dermatological use. Microbiological assays demonstrated significant antimicrobial activity against Gram-positive (Staphylococcus aureus) and resistant Gram-negative strains (Escherichia coli and Enterobacter cloacae), attributed to the synergistic action of nisin and citric acid, which enhanced bacterial outer membrane permeability. The antioxidant capacity was confirmed through DPPH radical scavenging assays, indicating a progressive release of bioactive compounds over time. Scanning electron microscopy (SEM) analyses revealed good integration of biopolymers within the matrix. These results suggest that the strategic combination of natural biopolymers and antimicrobial agents produced a functional system with improved mechanical properties, a broadened antimicrobial spectrum, and promising potential as a bioactive wound dressing for the treatment of infected skin lesions.