Engineering a dual-action nitric oxide and propolis releasing polymeric matrix for extended antimicrobial efficacy

Infection of indwelling medical devices is one of the major healthcare threats, often resulting in sepsis, device failure, and even death. The conventional treatment approach for these infections is often systemic, utilizing antibiotics that may lead to unwanted side effects or the development of antibiotic-resistant bacteria. This has led to research into an effective antimicrobial technique that would not further contribute to antimicrobial resistance. Nitric oxide (NO) releasing materials are excellent antimicrobial agents that effectively thwart multiple bacterial strains. Additionally, the incorporation of natural antimicrobial agents such as propolis is a facile and cost-effective way to increase the efficacy and longevity of NO releasing materials without posing any cytotoxic concern. Herein, the fabrication of a NO and propolis releasing polymeric matrix enhanced antimicrobial efficacy against E. coli, S. aureus, and C. albicans. The material was able to release a physiologically relevant amount of NO for 7 days while exhibiting excellent antimicrobial activity through the action of propolis well beyond day 7. The as-reported NO and propolis releasing polymeric substrate showed a significant reduction in the viability of S. aureus after incubation under physiological conditions for 28 days, while demonstrating excellent cytocompatibility against 3T3 mouse fibroblast cells. Thus, the reported facile technique for the fabrication of a dual-action antimicrobial polymer can open avenues for their use in indwelling medical device applications.