Phloxine B-loaded polymersomes enable eradication of and in antimicrobial photodynamic therapy.

Utilised for decades in cancer therapy, the application of photosensitisers in antimicrobial photodynamic therapy is now well explored. In a smart wound dressing, an externally triggered antimicrobial strategy would enable on-demand infection eradication. Hence, in this work, the light-initiated production of reactive oxygen species from photosensitiser-loaded nanocarriers was explored. Such systems enable highly localised delivery of photosensitiser, without associated "dark toxicity" effects. The amphiphilic block copolymer PEG--PLA was synthesised ring-opening polymerisation in the melt. the solvent shift method, the polymer was self-assembled into nanosized vesicles encapsulating Phloxine B, a commercial water-soluble photosensitiser. bacteria experiments with Phloxine B-loaded vesicles relied on localised illumination with green light (530 nm, 4 mW cm, 15 minutes) to generate O, killing the bacterial cells. A 6.8 log reduction in CFU mL for and a 4.7 log reduction in CFU mL for are reported. Incorporation of these vesicles into a support matrix in combination with a reporter dye could provide a pathway towards promising smart wound dressings.