An ex-vivo study to investigate the potential of Staphylococcus epidermidis lysate to improve wound healing in diabetic patients

Abstract

Appropriate treatment of non-healing diabetic foot ulcers is challenging as the whole skin repair process is complicated. Current therapeutic strategies have to be evolved for better efficacy. Staphylococcus epidermidis (S. epidermidis) is a commensal having probiotic properties. The wound healing potential of its lysate was explored using skin biopsies. Full-thickness skin, obtained from individuals with and without diabetes, was wounded using an excisional punch. Skin explants were cultured using a serum-free medium in the presence and absence of S. epidermidis lysate. The ability of the lysate to stimulate re-epithelialisation was assessed in an ex-vivo human skin model of wounding from patients with and without diabetes. Epithelial tongue length was significantly reduced in diabetic wounds in comparison to non-diabetic samples, even after 12 days post-wounding. Re-epithelialisation was augmented considerably in S. epidermidis lysate-treated wounds ex-vivo. In non-diabetic samples, the increase was twofold greater but in diabetic samples, only a slight enhancement in tongue length was observed in comparison to the control (untreated sample). The epidermal thickness also increased 7.7-fold in treated wounds in comparison to 4.4-fold in untreated samples. The cell number per unit area showed a significant increase in comparison to untreated control and the number of Ki-67 positive cells was slighter greater indicating increased expression of the proliferation marker in the newly formed epithelial tongue area in lysate-treated samples (both diabetic and non-diabetic). S. epidermidis lysate promotes re-epithelialisation in both diabetic and non-diabetic skin biopsies and may be used to accelerate healing in chronic diabetic ulcer wounds. Its therapeutic potential needs to be explored further with in vivo and molecular studies.