Engineering an electroactive bacterial cellulose-carbon nanotube composite membrane against Staphylococcus aureus

Staphylococcus aureus is the leading cause of skin infections in the U.S., and its rapid evolution and resistance to antibiotics create a barrier to effective treatment. In this study, we engineered a composite membrane with bacterial cellulose and carbon nanotubes (BC-CNT) as an electroactive dressing to rapidly eradicate vancomycin-intermediate S. aureus. Nonpathogenic Komagataeibacter sucrofermentans produced the BC membrane at an air-liquid interface. Then, carboxyl-functionalized multi-walled CNTs were integrated into decellularized BC to create stable and electrically conductive BC-CNT dressings. The electric potential and ionic flux across BC-CNT were modeled and standardized via chronoamperometry for experimental validation. We found that treatment with electroactive BC-CNT increases S. aureus sensitivity to vancomycin and prevents macro-scale biofilm formation. The bactericidal efficacy of the composite membrane is consistent with electrochemical stress caused by voltage mediated with BC-CNT. After a single hour of combinatorial electrical and drug treatment, biofilm-forming capacity was inhibited by nearly 92 %. These results advance applications of electrochemistry in medicine and create a new direction to overcome S. aureus infections on skin and soft tissues.