Hybrid hydrogel–nanocarrier antimicrobial photodynamic therapy with Allura red against clostridium perfringens under oxygen-limited (hypoxic) conditions: An in vitro proof-of-concept

This study demonstrates an in vitro, platform-level proof-of-concept for an oxygen-tolerant antimicrobial photodynamic therapy system under oxygen-limited conditions. Allura Red was used exclusively as a conservative stress-test chromophore and is not proposed as a clinical photosensitizer. The findings indicate that platform design-hydrogel retention and nanocarrier-mediated bacterial contact/targeting-rather than chromophore efficiency alone, plays a central role in sustaining measurable photodynamic activity under oxygen-limited conditions.