Polycaprolactone/gelatin-QAS/bioglass nanofibres accelerate diabetic chronic wound healing by improving dysfunction of fibroblasts

Worldwide, more than 25 % of patients with diabetes develop chronic diabetic wounds in their lifetime. Infection and dysfunctional fibroblasts represent two significant etiological factors contributing to impaired wound healing in patients with diabetes. It is therefore evident that the development of wound dressings with both anti-infective and DM fibroblast modulating functions has the potential for clinical applications. In this study, a PCL/gelatine-quaternary ammonium salts (QAS)/bioglass (BG) electrospun nanofibrous membrane was developed with physico-chemical and biological properties that not only meet the clinical requirements for wound dressings but also exhibit remarkable moisturising (water adsorption rate of 382.39 ± 4.36 %) and tear-resistance properties (a tear strength of ~5.5 MPa). The incorporation of QAS and BG has enhanced the biocompatibility and bioactivity of the nanofibres, while also imparting remarkable antimicrobial properties. The antibacterial efficacy of PGQ-BG against E. coli and S. aureus was found to be 92.8 ± 0.78 % and 99.3 ± 0.55 %, respectively. Moreover, it was demonstrated that PGQ-BG nanofibers exerted a promoting effect on the extracellular matrix (ECM) in dysfunctional fibroblasts and upregulated the expression level of α-smooth muscle actin (α-SMA), a marker of their differentiation to myofibroblasts in vitro and in vivo. Furthermore, the COL-III/COL-I ratio was significantly increased, indicating that PGQ-BG may also accelerate wound healing. The nanofibrous dressing reduced scar formation by increasing the COL-III/COL-I ratio. This is the first report of BG improving fibroblast dysfunction via COL-III and COL-I promotion in fibroblasts, both in vitro and in vivo. Therefore, this novel bioactive nanofibrous dressing represents an effective and safe therapeutic strategy for improving chronic wound healing in patients with diabetes.