Onychomycoses represent approximately 50 % of all nail diseases worldwide. In warmer and more humid countries like Brazil, the incidence of onychomycoses 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 onychomycoses caused by NDM. Although some laser and light treatments have demonstrated clinical efficacy against onychomycosis, their US Food and Drug Administration (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 therapies against onychomycosis caused by Fusarium oxysporum 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) 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 to those observed in the clinic, when compared to published in vitro models for laser and light therapies. Thus, our model might represent an important tool for the initial testing, validation, and “fine-tuning” of laser and light therapies against onychomycosis.
Biofilms Intense pulsed light Laser therapy Nd:YAG Near infrared Onychomycosis
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The authors thank Dr. Wanderley de Souza from the Laboratory of Cellular Ultrastructure Hertha Mayer (Federal University of Rio de Janeiro, RJ, Brazil) for providing the microscopy platform used in this work and Beatriz Bastos Fonseca for her help with SEM sample preparation. The work was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação Carlos Chagas Filho de Amparo à Pesquisa do Rio de Janeiro (FAPERJ), and Fundação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
Conflict of interest
None to declare.
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