Potential effect of hypericin-loaded mucoadhesive nanostructured systems associated with antimicrobial photodynamic and sonodynamic therapies against Candida albicans strains

Abstract

Photodynamic therapy (aPDT) is a potent alternative for the treatment of fungal infections such as vulvovaginal candidiasis. PDT use a photosensitizer (PS) and visible light, however, the penetration of light into human tissue is still limited. A considerably novel technique is being researched to improve this disadvantage. Sonodynamic therapy (SDT) uses ultrasound (US) which, unlike light, can propagate deeper into the tissue, since the US generates inertial cavitation, producing singlet oxygen. The fungicidal effects of aPDT/SDT therapies against Candida albicans strains use a natural PS extracted from Hipericum perforatum, hypericin (HYP). HYP has attracted researchers' attention because of the high capacity to produce oxygen; however, it may be systemically distributed, causing the death of undesirable cells. To overcome this limitation, HYP has been incorporated into mucoadhesive nanostructures systems, such as the nanostructured lipid carrier dispersed in hydrogels in situ. The systems are promising for HYP vaginal delivery, as they enable to minimize its toxicity and adverse reactions, promote a sustained release drug, and thus increase drug delivery time in the vaginal environment. The systems combined with the effective HYP-mediated aPDT/SDT therapies may present important responses to the treatment of fungal infections.