Rapid formulation alginate dressing with sustained nitric oxide release: a dual-action approach for antimicrobial and angiogenic benefits.

Infected chronic wounds resulting from bacterial, viral, or other microbial invasion disrupt the normal wound-healing process, often prolonging recovery and requiring surgical intervention. A high nitric oxide (NO) concentration damages bacterial DNA and disrupts metabolic functions, indicating its effective antibacterial potential, whereas a low NO concentration exerts detectable provascularization activity. These properties render NO an effective treatment agent for infected chronic wounds. However, challenges remain in generating NO efficiently, controlling its dosage, and selecting an appropriate carrier for wound treatment. To overcome these problems, we synthesized S-nitrosoglutathione (GSNO) and thiolated alginate (SA-SH). GSNO was used as the NO source for continuous release. The content of the thiolate group in SA-SH was 158.10 ± 10.84 μmol/g. The GSNO and SA-SH mixture was quickly solidified in the presence of calcium ions to obtain GSNO/SA-SH hydrogel (SSG). This mixture is suitable for treating irregular wounds. In addition, early release of high-dose NO inhibits bacteria (first 72 h), whereas late release of low-dose NO promotes angiogenesis (72-144 h). Experiments conducted on a rat infection model showed that the release of NO reduced infection and effectively inhibited bacterial invasion of tissues. On the 14th day after surgery, the healing rate of the control group was 82 %, whereas that of the SSG group was 100 %. The degree of angiogenesis in the SSG group was 1.5 times that in the SA-SH group, indicating that NO accelerates angiogenesis. Thus, a rapid-forming, NO releasing dressing can effectively treat infected wounds.