Barley β-glucan gelatin sponge improves impaired wound healing in diabetic and immunosuppressed mice by regulating macrophage polarization

Abstract β-glucan has been reported to improve chronic wound healing. Barley β-glucans are abundantly available, are easy to extract, and have high biological activity. Gelatin is a well-known hemostatic agent and can be processed into a variety of forms for clinical applications.Dysfunction in macrophage phenotype transition is one of the primary reasons for impaired wound healing. In this study, we evaluated the effects of barley β-glucan gelatin sponge on delayed wound healing and its’ effect on macrophage function. We observed that barley β-glucan gelatin sponge could alleviate delayed wound healing in immunosuppressed and diabetic db/db mice. Furthermore, it promoted macrophage recruitment to the wound site, decreased iNOS expression, and increased CD206 levels in granulation tissues. With regards to db/db mice, barley β-glucans gelatin sponge decreased the expression of M1 type cytokines (TNF-α mRNA and protein, IL-6/IL-12A mRNA) on day 7 post wounding and increased expression levels of M2 type cytokines (VEGF and IL-10mRNA, TGF-β protein) on day 14. In immunosuppressed mice, barley β-glucan gelatin sponge decreased IL-6 mRNA levels and increased TGF-β mRNA levels on days 3 and 7 post wound initiation. Furthermore, it increased VEGF levels during granulation. This suggested barley β-glucan gelatin sponge alleviated impaired wound healing by regulating macrophage phenotype transition. In conclusion, barley β-glucans gelatin sponge is a more effective and safer topical agent compared to traditional gelatin sponge for treating delayed wound healing and could be a treatment option for patients with chronic wounds.