Nitric Oxide-Releasing Bacterial Cellulose/Chitosan Crosslinked Hydrogels for the Treatment of Polymicrobial Wound Infections

Polymicrobial wound infections are a major cause of infectious disease-related morbidity and mortality worldwide. In this study, we prepared a nitric oxide (NO)-releasing oxidized bacterial cellulose/chitosan (BC(TO)/CHI) crosslinked hydrogel to effectively treat polymicrobial wound infections. Linear polyethyleneimine diazeniumdiolate (PEI/NO) was used as the NO donor. The aldehyde group of BC(TO) and the amine of CHI were used as crosslinked hydrogel-based materials; their high NO loading capacity and antibacterial activity on the treatment of polymicrobial-infected wounds were investigated. The blank and NO-loaded crosslinked hydrogels, namely BC(TO)-CHI and BC(TO)-CHI-PEI/NO, were characterized according to their morphologies, chemical properties, and drug loading. BC(TO)-CHI-PEI/NO exhibited sustained drug release over four days. The high NO loading of BC(TO)-CHI-PEI/NO enhanced the bactericidal efficacy against multiple bacteria compared with BC(TO)-CHI. Furthermore, compared with blank hydrogels, BC(TO)-CHI-PEI/NO has a favorable rheological property due to the addition of a polymer-based NO donor. Moreover, BC(TO)-CHI-PEI/NO significantly accelerated wound healing and re-epithelialization in a mouse model of polymicrobial-infected wounds. We also found that both crosslinked hydrogels were nontoxic to healthy mammalian fibroblast cells. Therefore, our data suggest that the BC(TO)-CHI-PEI/NO developed in this study improves the efficacy of NO in the treatment of polymicrobial wound infections.