Bacterial phototoxicity of lumichrome photocrosslinked collagen hydrogels

In response to the World Health Organization's (WHO) call develop alternative antibacterial methods, we investigate endogenous compounds and biopolymers. Lumichrome (LC) is an endogenous, lipophilic degradation product of riboflavin (vitamin B2) that can act as a photosensitizer for antimicrobial applications. LC also photocrosslinker collagen. Crosslinked collagen hydrogels were prepared with two types cyclodextrins (CDs), namely (2-hydroxypropyl)-β-CD (HPβCD) -γ-CD (HPγCD), improve aqueous solubility LC. The release from gels phototoxic effect UVA-irradiated against planktonic Staphylococcus (S.) aureus investigated. Irradiation complexed either CD resulted in similar levels bacterial death despite HPγCD containing half concentration HPβCD gels. This may be explained by higher complexation efficiency stability LC-HPβCD complex, slowing down release. Following treatment, small colony variants S. observed. study proof concept effects embedded biopolymer sustainable conventional therapy of, e.g., infected wounds.