Mechanism of action of montmorillonite powder on injury and repair factors in Stage II pressure ulcers in model mice.

Background: This study aims to elucidate the therapeutic effects and underlying mechanisms of montmorillonite powder on wound healing in mice with Stage II pressure ulcers, thereby providing a robust foundation for its clinical application in the treatment of such ulcers.

Materials and methods: Sixty 8-week-old specific pathogen-free male BALB/c mice were randomly allocated into three groups: a model group (where Stage II pressure ulcers were induced using the magnet pressure method and the wounds were dressed with gauze soaked in 0.9% sodium chloride solution), a treatment group (where, following the induction of Stage II pressure ulcer models, wounds were uniformly treated with montmorillonite powder), and a control group (where magnets were placed in the same location without exerting magnetic pressure). Skin histopathology was assessed via light microscopy. Wound healing progress over various intervals was quantified utilizing Image-Pro Plus software. Histopathological alterations in the wounds were examined through hematoxylin and eosin (H&E) staining. The expression of growth factor proteins within the wound tissue was analyzed using the streptavidin-peroxidase method. Furthermore, the levels of vascular endothelial growth factor (VEGF), collagen types I and III (COL-I, COL-III) proteins were quantified via Western blotting, serum concentrations of inflammatory mediators in mice were determined by enzyme-linked immunosorbent assay, and the levels of oxidative stress markers in wound tissues were measured using UV-visible spectrophotometry.

Results: The treatment group exhibited significantly reduced serum levels of interleukin-1β, interleukin-6, and tumor necrosis factor-alpha, and elevated levels of interleukin-4 compared to the model group (p < 0.05). Additionally, the expression of transforming growth factor-beta1, basic fibroblast growth factor, epidermal growth factor, VEGF, COL-I, and COL-III proteins in wound tissues was significantly higher in the treatment group than in the model group (p < 0.05). Levels of superoxide dismutase and glutathione peroxidase in wound tissues were higher, and levels of malondialdehyde were lower in the treatment group compared to the model group (p < 0.05).

Conclusion: Montmorillonite powder facilitates wound healing and augments the healing rate of Stage II pressure ulcers in model mice. Its mechanism of action is likely associated with mitigating wound inflammation, reducing oxidative stress damage, promoting angiogenesis, and enhancing the synthesis of growth factors and collagen.