An AIE fungal vacuole membrane probe toward species differentiation, vacuole formation visualization, and targeted photodynamic therapy

Abstract

Vacuoles are unique organelles of fungi. The development of probes targeting the vacuoles membrane will enable visualization of physiological processes and precise diagnosis and therapy. Herein, a zwitterionic molecule, MXF-R, comprising of an aggregation-induced emission (AIE) photosensitizing unit and an antibiotic moxifloxacin, was found capable of specifically imaging vacuole membrane and using for targeted antifungal therapy. MXF-R demonstrated a higher signal-to-noise ratio, stronger targeting capability, and better biocompatibility than the commercial probe FM4-64. By using MXF-R, real-time visualization of vacuole formation during Candida albicans (C. albicans) proliferation was achieved. More importantly, owing to its varying staining ability towards different fungus, MXF-R could be used to quickly identify C. albicans in mixed strains by fluorescence imaging. Moreover, MXF-R exhibits a remarkable ability to generate reactive oxygen species under white light, effectively eradicating C. albicans by disrupting membrane structure. This antifungal therapy of membrane damage is more effective than clinical drug fluconazole. Therefore, this work not only presents the initial discovery of a probe targeting vacuolar membrane, but also provides a way to develop novel materials to realize integrated diagnosis and therapy.