A collagen-based theranostic wound dressing with visual, long-lasting infection detection capability

Area of Science:

• Biomaterials Science
• Wound Care Technology
• Medical Diagnostics

Background:

• Continuous wound monitoring is crucial for minimizing infection severity and guiding therapeutic interventions.
• Integrating infection detection into wound dressings remains a significant challenge in current medical technology.

Purpose of the Study:

• To develop a theranostic wound dressing by combining a collagen-based wound contact layer with a pH-sensitive halochromic dye, bromothymol blue (BTB).
• To evaluate two methods, electrospinning and drop-casting, for integrating BTB into the dressing to achieve long-lasting visual infection detection.
• To assess the dye retention, color change kinetics, and biocompatibility of the developed theranostic dressings.

Main Methods:

• Collagen-based hydrogels were functionalized with bromothymol blue (BTB) using electrospinning and drop-casting techniques.
• Dye loading efficiency, color change response to pH variations (simulating infection), and BTB retention over 96 hours were quantified.
• Fourier-transform infrared spectroscopy (ATR-FTIR) and differential scanning calorimetry (DSC) were used to analyze interactions between collagen and BTB.
• L929 fibroblast viability was assessed to determine the biocompatibility of the dressing extracts.

Main Results:

• Both electrospun and drop-cast systems achieved high BTB loading efficiency (99 wt%) and rapid color change (<1 min) in simulated wound fluid.
• Drop-cast samples demonstrated significantly superior BTB retention (85 wt% after 96h) compared to electrospun prototypes (>80% BTB release).
• Evidence of secondary interactions between collagen and BTB was observed, correlating with enhanced dye confinement and stable color change.
• Drop-cast dressing extracts showed high L929 fibroblast viability (92% at 7 days), indicating good biocompatibility.

Conclusions:

• The drop-casting method provides a robust strategy for creating theranostic wound dressings with durable, visual infection detection capabilities.
• The developed collagen-BTB theranostic dressing platform is simple, cell-friendly, and suitable for industrial scale-up.
• This technology offers a promising approach for accelerated wound healing and early infection diagnosis in clinical settings.