| Congresso Brasileiro de Microbiologia 2023 | Resumo: 924-1 | ||||
Resumo:In recent years, titanium and its alloys have been widely used for manufacturing dental and orthopedic implants due to their excellent mechanical and biocompatible properties. However, infection associated with the formation of microbial biofilms has been one of the main causes of failure of these implants. Thus, the coating of surfaces containing antimicrobial compounds can be an efficient alternative for preventing biofilm growth on implant surfaces. The antifungal activity of alpha - silver tungstate microcrystals dispersed in an aqueous medium has already been well described in the literature. Furthermore, in previous studies, irradiation of α-Ag2WO4 by electron beam allowed significant improvements in the antimicrobial properties of this material, mainly due to the formation of metallic silver nanoparticles on its surface. However, further investigation is still needed for the coating of titanium alloys using this compound. Candida albicans is an opportunistic pathogen, commonly found in the human microbiota. Imbalances in the host's immune system allow this fungus to cause superficial or invasive infections. Thus, the aim of the study was to evaluate the antimicrobial activity of titanium discs coated with α-Ag2WO4 microcrystals, irradiated with electron beam, against Candida albicans biofilms (ATCC 90028). The microcrystals were synthesized by the co-precipitation method and grade 2 titanium alloy discs, measuring 11 mm in diameter and 3 mm in thickness, were used. For the deposition on the discs, a solution of polyethylene glycol and microcrystals was prepared, adding 10 mg of α-Ag2WO4 for each 1 mL of the solution and the deposition was conducted by the Spin-Coating method. Part of coated discs were irradiated for 5 minutes in a portable irradiation equipment (40 kV acceleration, 15 mA current). Afterwards, each disc was transferred to wells of a 24-well plate and 1 mL of the fungal suspension (1x106 CFU/mL) in yeast nitrogen base broth was added onto the titanium discs followed by incubation at 37°C, under agitation for 1hour and 30 minutes. After this period, the discs were carefully washed twice with buffered saline solution (PBS) and 1 mL of Roswell Park Memorial Institute medium (RPMI - 1640) was added to each well. After 24 hours, the culture medium was renewed and the samples were incubated for another 24 hours. For the quantification of colony forming units per milliliter (CFU/mL), the discs were carefully scraped with sterile swabs for 30 seconds. Then, the swab, along with the entire contents of the well, was transferred to a sterile microtube. Next, this micro-tube was homogenized in a vortex for 1 minute and the samples were serially diluted up to 10-4. Thereafter, 25 µL aliquots of each dilution were seeded on Sabouraud dextrose agar, supplemented with chloramphenicol (5 μg/mL). Colonies were counted after 48 hours of growth and assays were performed on three different occasions, in triplicates (n=9). Data were analyzed using Kruskal-Wallis analysis, followed by Dunn's post-test. From the results obtained, it was possible to observe that colonies of C. albicans were not recovered in the groups in which discs were coated, with and without irradiation, and the reduction was 6.96 log10 (p< 0.0001). Thus, it is concluded that titanium discs coated with α-Ag2WO4 are capable of inhibiting C. albicans biofilm formation. Palavras-chave: Candida albicans, Coating, Silver tungstate, Titanium Agência de fomento:FAPESP Nº: 13/07296-2 e 22/08487-5|CNPq Nº: 403985/2021-8 e 105473∕2022-7 | EUROPEAN UNION-NEXT GENERATION: MGS/2021/21 (UP2021-021). | |||||