Near Infrared Photo‐Antimicrobial Targeting Therapy for <i>Candida albicans</i>

Abstract

Abstract Drug‐resistant microorganisms are a pressing issue, and innovative antimicrobial therapies are required; antibodies targeting antigens on pathogen surfaces have emerged as one such modality. IgY, abundant in chicken egg yolk, confers passive immunity, and is effective against various pathogens; however, its antimicrobial effects remain limited. Near‐infrared photoimmunotherapy (NIR‐PIT), originally developed as a cancer treatment, specifically kills cancer cells via a photosensitizing phthalocyanine dye (IRDye700Dx; IR700)‐conjugated monoclonal antibody, and irradiating NIR light. IgY‐photo‐antimicrobial targeting therapy (IgY‐PAT 2 ), exploiting NIR‐PIT, is investigated to destroy only microorganisms. IR700 is conjugated with anti‐ Candida albicans IgY (CA‐IgY) to generate CA‐IgY‐IR700, which specifically binds various Candida spp. (and not human skin cells). The antimicrobial effect of CA‐IgY‐PAT 2 is dependent on the NIR‐light dose ( p &lt; 0.0001). CA‐IgY‐PAT 2 significantly reduces the area of ulcers in a mouse model of CA‐infected cutaneous ulcers ( p &lt; 0.0001), indicating that CA‐IgY‐PAT 2 is a new promising therapeutic method for CA infection.