Photodynamic Eradication of Trichophyton rubrum and Candida albicans

Conventional methods of onychomycosis treatment are ineffective in some cases because the cure of onychomycosis very often depends on the patient’s individual response to the treatment; therefore, there is a crucial need to research and develop new methods of onychomycosis therapy. One of the most innovative treatments is photodynamic therapy (PDT) using photosensitizers (PSs). However, effective treatment depends on the correct choice of photosensitizer and substances that improve the characteristics of the final formulation. The aim of our work was to find an effective formulation for the treatment of onychomycosis. To achieve this goal, we tested the effect of three types of PSs, rose Bengal (RB), malachite green oxalate (MGO), and methylene blue (MB), on Candida albicans. The most effective PS was RB, and so the study was continued with Trichophyton rubrum. Additional comparative studies were carried out on substances included in the formulation (urea and thiourea), focusing on their antifungal activity, which can improve penetration through the nail plate. The composition of the formulation that achieved 100% eradication of Trichophyton rubrum under our conditions consisted of 150 μM RB, 5% urea, and 0.5% thiourea in glycerol/water (70/30%, w/w) solution. A white luminescent lamp was used as a light source (1.9 ± 0.1 mW cm−2). Stability of the formulation was checked. The selected formulation shows potential for future simplification and acceleration of PDT treatment of onychomycosis.

Oxidative decolorization of a malachite green oxalate dye through the Photochemical Advanced Oxidation Processes

<p>This report was aimed at an investigation of efficiency for Photochemical Advanced Oxidation Processes (UV photolysis, UV/H2O2, UV/TiO2, UV/H2O2/TiO2 and UV/H2O2/Fe2+ processes) to decolorize Malachite Green Oxalate (MGO) dye. Experimental runs were performed using laboratory scale photochemical reactor. About 98% decolorization was obtained with initial 100 ppm MGO dye in Photo-Fenton process under optimal conditions (60 ppm Fe2+ concentration, 12 mM of oxidant concentration, at pH 3.0 for 60 min). 97% decolorization was obtained using UV/H2O2/TiO2 process having [TiO2]o of 0.6 gm/L for similar reaction conditions. The percentage decolorization of MGO was in range of 94-95% for both UV/TiO2 and UV/H2O2 processes. Concentration of ferrous salt (60 ppm) was considered as an optimal value to carry out the UV/H2O2/Fe2+ process for MGO decolorization. Influence of oxidant (H2O2) and Fe2+ ions for oxidation of MGO was studied in Photo-Fenton process. Sulphate radical based AOPs was proved to be more effective in treating MGO dye with irradiation. Results indicate that decolorization efficiency by Photochemical AOPs for MGO dye in photochemical reactor were more efficient. Pseudo-first-order model of kinetics was noticed to be the best model fit to explain the decolorization of MGO dye solution.</p>

Solid-Liquid Separation Properties of Thermoregulated Dicationic Ionic Liquid as Extractant of Dyes from Aqueous Solution

Two thermoregulated dicationic ionic liquids were synthesized and applied for effective extraction of the common dye malachite green oxalate (MG). The extraction parameters such as amount of ionic liquids, pH of water phase, extraction time, cooling time, and centrifugal time on the extraction efficiency were investigated systematically. It revealed that the dye has been successfully extracted into the ionic liquids, with high extraction efficiency higher than 98%, and recovery of 98.2%–100.8%, respectively. Furthermore, these ionic liquids can be recycled easily after elution. The reusable yields were 87.1% and 88.7%. The extraction of the dye into the thermoregulated ionic liquid provides a method of minimizing pollution of waste water potentially.