Polycaprolactone/polyethylene glycol electrospun mats with pH-responsiveness for real-time sensing in chronic wound healing

Constant monitoring of the healing process is crucial to prevent wound chronicity. In this study, we developed pH-responsive nanofibrous mats by incorporating anthocyanins extracted from red cabbage, red radish, and purple sweet potato into polycaprolactone (PCL)/polyethylene glycol (PEG) blends at 100:0, 90:10, and 80:20 v /v ratios via electrospinning. The natural extracts were characterized for phenolic content, antioxidant capacity, and halochromic response within pH 4.0–10.0, with red radish extract showing the highest color sensitivity and stability. Incorporation of PEG improved fiber morphology and hydrophilicity, with the 90:10 PCL/PEG ratio providing the optimal balance between mechanical strength and color response. Mats loaded with 5 mg/mL red radish extract exhibited a clear and irreversible color shift from pink (pH 4.0–6.0) to purple/blue (pH 7.0–9.0) and green (pH ≥ 10.0), enabling straightforward visual discrimination across physiologically relevant pH ranges. Cytocompatibility assays indicated >80% cell viability, and antioxidant activity reached ≈50%, suggesting additional therapeutic potential. These findings highlight the potential of the developed mats as wound dressings capable of real-time pH monitoring and supporting a more informed approach to wound management. Graphical abstract • Natural anthocyanins enable pH-responsive wound monitoring materials. • PCL/PEG electrospun mats show tunable color change from pH 4 to 10. • Red radish extract yields optimal sensitivity and color stability. • PEG improves fiber uniformity, hydrophilicity, and mechanical balance. • Developed mats are biocompatible and suitable for chronic wound care.