Nitric oxide-releasing self-healing hydrogel for antibacterial and antibiofilm efficacy against polymicrobial infection

<b>Aim:</b> Bacterial infections and the formation of biofilms are currently key factors in the delay of wound healing. S-Nitroso glutathione (GSNO) is recognized as a nitric oxide (NO) donor that exhibits potent antibacterial and antibiofilm activities. However, some of the stability limitations of NO require it to be prepared pharmaceutically.<b>Materials & methods:</b> Here, we developed a self-healing hydrogel dressing consisting of GSNO, polyvinyl alcohol/borax (PVA/B) and carboxymethyl chitosan (cmCHI). This research aimed to determine the antibacterial and antibiofilm activities of a self-healing hydrogel (PVA-B-cmCHI/GSNO) against multiple bacteria and polymicrobial biofilms.<b>Results:</b> Forty mg/ml PVA-B-cmCHI/GSNO significantly increased the antibacterial activity against <i>Pseudomonas aeruginosa</i>, <i>S. aureus</i>, Methicillin resistant <i>Staphylococcus aureus</i> (MRSA), as indicated by a >5 log reduction in bacterial viability (∼99.999% killing). PVA-B-cmCHI/GSNO showed antibiofilm activity three-times greater than that of the blank self-healing hydrogel (PVA-B-cmCHI) by inhibiting 80% of the biofilm formation.<b>Conclusion:</b> The results suggest that the NO-releasing self-healing hydrogels exhibit notable antibacterial and antibiofilm properties and thus could be a promising approach for the treatment of bacterial or biofilm-infected wounds.