Susceptibility of Candida albicans and Candida glabrata biofilms to silver nanoparticles in intermediate and mature development phases

Abstract

Purpose: Silver nanoparticles (SN) have been studied as antibiofilm agents, to prevent Candida-associated denture stomatitis. Consequently, the aim of this study was to investigate the influence of the intermediate and maturation stages of Candida albicans and Candida glabrata biofilms development in the susceptibility to SN. Methods: SN (5 nm) suspensions were synthesized via reduction of silver nitrate by a solution of sodium citrate. These suspensions were used to treat, during 5 h, Candida biofilms grown on acrylic surfaces for 24- (intermediate stage) and 48-h (maturation stage), and their efficacy was determined by total biomass (using crystal violet staining) and colony forming units (CFU) quantification. Results: SN promoted significant reductions (p < 0.05) in the total biomass and in the number of CFUs of Candida biofilms ranging from 23-51.5% and 0.96-1.44-log10, respectively. Moreover, there were no significant differences in the total biofilm biomass (p > 0.05), when the different stages of biofilm development (24 or 48 h) were exposed to SN. Comparing the number of CFUs between 24- and 48-h biofilms treated with SN, a significant difference (p < 0.05) was found only for the strain C. albicans 324LA/94. Conclusions: It was concluded that, in general, the intermediate and maturation stages of biofilm development do not interfere in the susceptibility of C. albicans and C. glabrata biofilms to SN regarding. These findings are essential for the deployment of new therapies aimed at preventing denture stomatitis.