Claudia Sa Guimaraes
Federal University of Rio de Janeiro
Brazil
Title: A new model of in vitro fungal biofilms formed on human nail fragments allows reliable testing of laser and light therapy against onychomycosis
Biography
Biography: Claudia Sa Guimaraes
Abstract
Onychomycosis represent approximately 50% of all nail diseases worldwide. In warmer and more humid countries like Brazil, the incidence of onychomycosis caused by non-dermatophyte molds (NDM, including Fusarium spp.) or yeasts (including Candida albicans) has been increasing. Traditional antifungal treatments used for the dermatophyte-borne disease are less effective against onychomycosis caused by NDM. Although some laser and light treatments have demonstrated clinical efficacy against onychomycosis, their FDA-approval as 'first line' therapy is pending, partly due to the lack of well-demonstrated fungicidal activity in a reliable in vitro model. Here, we describe a reliable new in vitro model to determine the fungicidal activity of laser and light therapy against onychomycosis caused by Fusariumoxysporum and C. albicans. Biofilms formed in vitro on sterile human nail fragments were treated with 1064-nm neodymium-doped yttrium aluminum garnet laser (Nd:YAG), 420 nm intense pulsed light (IPL 420), IPL 420 followed by Nd:YAG, or near infrared light (NIR 700 - 1400 nm). Light and laser antibiofilm effects were evaluated using cell viability assay and scanning electron microscopy (SEM). All treatments were highly effective against C. albicans and F. oxysporum biofilms, resulting in decreases in cell viability of 45-60% for C. albicans and 92-100% for F. oxysporum. The model described here yielded fungicidal activities that matched more closely those observed in the clinic, when compared to published in vitro models for laser and light therapy. Thus, our model might represent an important tool for the initial testing, validation and 'fine-tuning' of laser and light therapy against onychomychosis.
