Onychomycosis is a common fungal nail infection for which new antifungals are needed to overcome antimicrobial resistance and the limitations of conventional treatments. This study reports the development of antifungal nail lacquers containing oregano essential oil (OEO), rosemary essential oil (REO), and biogenic silver nanoparticles (bioAgNPs). The formulations (F) were tested against dermatophytes using agar diffusion, ex vivo nail infection, and scanning electron microscopy techniques. They were evaluated for their pharmacotechnical characteristics and by FTIR-PAS to assess permeation across the nail. F-OEO and F-OEO/bioAgNPs were promising candidates for the final nail lacquer formulation, as they permeated through the nail and showed antifungal efficacy against dermatophytes-contaminated nails after 5 days of treatment. Treated nails exhibited decreased hyphae and spores compared to the untreated control; the hyphae were atypically flattened, indicating loss of cytoplasmic content due to damage to the cytoplasmic membrane. The formulations were stable after centrifugation and thermal stress, maintaining organoleptic and physicochemical characteristics. Both F-OEO and F-OEO/bioAgNPs had pH compatible with the nail and drying times (59–90 s) within the reference for nail lacquer. For the first time, OEO and bioAgNPs were incorporated into nail lacquer, resulting in a natural and nanotechnological product for onychomycosis that could combat microbial resistance.

Graphical Biosynthesis and antifungal activity of silver nanoparticles stabilized with naringenin.

This study aims to evaluate in vitro the whitening effects of gels containing hydrogen peroxide at acidic and basic pH using internal and external techniques. Forty artificially darkened bovine incisors were split into four groups: bleaching on the buccal surface with HPE (HP Blue 35%, FGM), at basic pH; PBE (Potenza Bianco 38%, PHS), at acidic pH; bleaching in the pulp chamber with HPI at basic pH; and with PBI at acidic pH. CIELab color parameters, microhardness, roughness, enamel demineralization (FT-Raman), and surface topography (SEM) were evaluated in enamel/dentin blocks after bleaching (T0) and seven days after immersion in saliva (T7). Bleaching agent diffusion was evaluated after 30 minutes, while pH was measured throughout the application period. Physicochemical analysis showed a reduction in the mineral-matrix ratio in both groups after bleaching and at 7 days. Roughness increased over time in the PBE and HPE groups. Porosity increased, but decreased after 7 days of immersion in saliva. Bleaching gels were different at T0 and T7, with acidic pH gel promoting greater whitening (T7) and enamel roughness. Raman scanning demonstrated that the bleaches propagated across the enamel layer with increased concentration at the dentin-enamel-junction and decreasing diffusion gradient along the dentin. The gel with acidic pH promoted a greater increase in enamel roughness and the 7-day immersion in saliva was not enough to restore initial roughness in either gel. The gel with basic pH showed a higher pH decay and a greater diffusion capacity in the dentin.

Onychomycosis is a common fungal nail infection for which new antibiotics are needed to overcome antifungal resistance and other limitations of conventional treatments. This study reports the development of antifungal nail lacquers containing oregano essential oil (OEO), rosemary essential oil (REO), and/or biogenic silver nanoparticles (bioAgNP). The formulations (F) were tested against dermatophytes by agar diffusion, ex vivo nail infection, and scanning electron microscopy techniques. They were evaluated pharmacotechnically and by FTIR-PAS to access permeation across the nail plate. F-OEO and F-OEO/Ag were promising for the final nail lacquer formulation, they permeated through the nail plate and showed antifungal efficacy against dermatophytes-contaminated nails after 5 days of treatment. The treated nails had decreased hyphae and spores compared to untreated control; the hyphae were atypically flattened which indicates loss of cytoplasmic content due to damage to cytoplasmic membrane. Formulations were stable after centrifugation and thermal stress, maintaining organoleptic and physicochemical characteristics. F-OEO and F-OEO/Ag had pH compatible with the nail, and drying time (59-90 s) within the reference for nail lacquer. For the first time, OEO and bioAgNP were incorporated in a nail lacquer, resulting in a natural and nanotechnological antifungal product for onychomycosis that may combat microbial resistance.

Onychomycosis is the most common nail infection, it has been attributed to fungal biofilms, and its treatment success is uncertain yet, but some natural products seem promising for topical treatment. The use of natural residues can also contribute to environmental sustainability and serve as valuable sources of bioactive compounds. This study aimed to evaluate the effectiveness of alcoholic propolis extract (PE) and a by-product extract (WPE) on monospecies mature fungal biofilms, and their permeation capacity in the human nail. The extracts were applied on seven-day biofilms produced by Fusarium oxysporum and Trichophyton rubrum, two important and antifungal resistant agents of onychomycosis. Photoacoustic spectroscopy evaluated the permeation of extracts across the nail fungal biofilms. Both extracts were able to significantly reduce the formed biofilms: WPE inhibited biofilms from both fungi at 137.50 μg/mL and PE was effective at 856.26 μg/mL (F. oxysporum) and 428.13 μg/mL (T. rubrum). Furthermore, both extracts showed a nail complete permeation, and WPE was the most efficient. Thus, our results confirm that these extracts would be safe and effective options for topical treatment for onychomycosis.