Abstract

Introduction:
Diabetic wounds are challenging to manage due to persistent hypoxia, oxidative stress, and poor angiogenesis, which often result in delayed closure and infection. Conventional dressings mainly act as protective barriers and do not actively improve the wound environment. To overcome these limitations, an oxygen-releasing xerogel was developed to deliver oxygen in a controlled manner while providing a structural matrix for tissue repair.

Methods:
A biopolymer–silica xerogel containing calcium peroxide (CaO₂) was prepared and optimized to maintain porosity and ensure steady oxygen release under physiological conditions. Oxygen release profiles, cytocompatibility with fibroblasts and keratinocytes, and antibacterial activity were assessed in vitro. The therapeutic effect was further evaluated in streptozotocin-induced diabetic rats, using gauze and hydrogel dressings as controls. Wound healing was followed over 21 days by measuring closure rates, histological changes, and angiogenesis markers.

Results:
The xerogel released oxygen for up to 72 hours, maintaining concentrations of 40–60 μm, a range supportive of tissue repair. Fibroblast and keratinocyte viability remained above 90%. In vitro antibacterial tests showed nearly 70% inhibition of bacterial growth compared with gauze. In the diabetic rat model, wounds treated with xerogel achieved about 85% closure by day 14, whereas gauze and hydrogel groups showed 55% and 68% closure, respectively (p < 0.01). Histological examination revealed improved re-epithelialization, greater collagen deposition, and a 2.5-fold increase in CD31-positive vessels in the xerogel group relative to controls.

Conclusions:
The study demonstrates that oxygen-releasing xerogels can actively enhance diabetic wound repair by supplying oxygen in a sustained fashion, limiting infection, and stimulating tissue regeneration. The quantitative improvements observed highlight their potential as next-generation dressings for chronic wound management.