Fabrication and characterization of cross-linked polymer hydrogel encapsulated with Nisin for wound dressing applications

Bioactive peptides like Nisin are gaining significant attention for their wound-healing and immunomodulatory properties. Hydrogels, with their high-water content resembling the natural extracellular matrix, provide a moist environment that supports cell migration, proliferation, and autolytic debridement. In this study, we developed a Nisin-encapsulated oxidized sodium alginate-collagen hydrogel through chemical crosslinking for wound-dressing applications. The ratio of polymers and Nisin was optimized based on swelling capacity and porosity, with the 5% formulation exhibiting the best performance. Characterization using SEM and XRD confirmed hydrogel formation by revealing larger pore sizes and reduced diffraction peaks, while MTT assays demonstrated a cell viability of 95.6% at 0.03 mM Nisin. The results further indicated that Nisin encapsulation enhanced the antioxidant and anti-inflammatory properties of the hydrogel, supporting its potential as an effective wound-dressing material. In vivo studies using a full-thickness wound rat model showed that the hydrogel promoted wound healing effectively. Acute dermal toxicity assessed using H&E staining revealed no toxicity in skin tissues at a dosage of 200 mg/kg BW. Furthermore, after 14 days of treatment, the residual wound area was 5% in the hydrogel-treated group, whereas the control group retained 30% of the original wound area. The treatment also significantly increased the expression of IL-10 (an anti-inflammatory cytokine) and decreased TNF-α (a pro-inflammatory cytokine) on both day 7 and day 14. These findings collectively highlight the strong potential of hydrogel for advanced wound-care applications.