Brenna Louise Cavalcanti Gondim1, Lúcio Roberto Cançado Castellano1, Ricardo Dias de Castro1, Giovanna Machado2, Hugo Lemes Carlo3, Ana Maria Gondim Valença1, Fabíola Galbiatti de Carvalho4. 1. Graduate Program in Dentistry, Federal University of Paraíba (UFPB), João Pessoa, 58051-900, Paraíba, Brazil. 2. Researcher of Centro de Tecnologia Estratégicas do Nordeste (CETENE), Av. Prof. Luís Freire, n.1, Cidade Universitária, Recife, Pernambuco, 50740-540, Brazil. 3. Department of Dentistry, Federal University of Juiz de Fora, Avenida Doutor Raimundo Rezende n. 330, Centro, Governador Valadares, Minas Gerais, 35012-140, Brazil. 4. Department of Dentistry, Federal University of Juiz de Fora, Avenida Doutor Raimundo Rezende n. 330, Centro, Governador Valadares, Minas Gerais, 35012-140, Brazil. Electronic address: fabiola.galbiatti@ufjf.edu.br.
Abstract
OBJECTIVES: Chitosan nanoparticles (ChNPs) have antifungal effects, however there is a lack of information about the effects of ChNPs against Candida biofilm on denture base surface. This study investigated the ChNPs effect against C. albicans biofilm adhesion and formation, and against Candida spp. biofilm on heat-cured acrylic resin. DESIGN: The ChNPs were synthetized (3800 μg/mL) and characterized by infra-red spectrophotometry and transmission electron microscopy. The minimum inhibitory/fungicidal concentrations (MIC/MFC) against Candida spp. were determined. The time-kill assay and changes on C. albicans micromorphology were evaluated. The % inhibition of ChNPs on C. albicans biofilm formation and reduction were investigated using 1 min and 8 h exposure. Candida biofilm was developed on resin surfaces and ChNPs were applied every 8 h for 5 days. After, fungal cells were counted (CFU/mL) and the surface roughness (Ra) and vickers microhardness (HV) of resin were analysed. For all experiments, sodium hypochlorite (NaOCl) was used as control. Data were analyzed by ANOVA, Tukey and paired t-tests (α = 0.05). RESULTS: The MIC80% of ChNPs was 30.1 μg/mL. ChNPs at 4 MIC showed complete inhibition in the time-kill assays. Blastoconidia cells were predominant after ChNPs application. The % inhibition ChNPs on C. albicans was proportional to its concentration, regardless of the exposure time. ChNPs decreased the CFU/mL of Candida spp. and showed lower alteration of HV and Ra values of resin surface compared to NaOCl. CONCLUSIONS: The ChNPs inhibited C. albicans biofilm, reduced Candida biofilm on resin and caused small changes in roughness and hardness of acrylic resin surface.
OBJECTIVES: Chitosan nanoparticles (ChNPs) have antifungal effects, however there is a lack of information about the effects of ChNPs against Candida biofilm on denture base surface. This study investigated the ChNPs effect against C. albicans biofilm adhesion and formation, and against Candida spp. biofilm on heat-cured acrylic resin. DESIGN: The ChNPs were synthetized (3800 μg/mL) and characterized by infra-red spectrophotometry and transmission electron microscopy. The minimum inhibitory/fungicidal concentrations (MIC/MFC) against Candida spp. were determined. The time-kill assay and changes on C. albicans micromorphology were evaluated. The % inhibition of ChNPs on C. albicans biofilm formation and reduction were investigated using 1 min and 8 h exposure. Candida biofilm was developed on resin surfaces and ChNPs were applied every 8 h for 5 days. After, fungal cells were counted (CFU/mL) and the surface roughness (Ra) and vickers microhardness (HV) of resin were analysed. For all experiments, sodium hypochlorite (NaOCl) was used as control. Data were analyzed by ANOVA, Tukey and paired t-tests (α = 0.05). RESULTS: The MIC80% of ChNPs was 30.1 μg/mL. ChNPs at 4 MIC showed complete inhibition in the time-kill assays. Blastoconidia cells were predominant after ChNPs application. The % inhibition ChNPs on C. albicans was proportional to its concentration, regardless of the exposure time. ChNPs decreased the CFU/mL of Candida spp. and showed lower alteration of HV and Ra values of resin surface compared to NaOCl. CONCLUSIONS: The ChNPs inhibited C. albicans biofilm, reduced Candida biofilm on resin and caused small changes in roughness and hardness of acrylic resin surface.
Authors: Brenda Kischkel; Suélen A Rossi; Samuel R Santos; Joshua D Nosanchuk; Luiz R Travassos; Carlos P Taborda Journal: Front Cell Infect Microbiol Date: 2020-09-03 Impact factor: 5.293