Effect of Silver Nanoparticles on Candida albicans Biofilms: an Ultrastructural Study
In this December 2015 clinical study published in the Journal of Nanobiotechnology, researchers demonstrated silver nanoparticles have a potent inhibitory effect on biofilm formation in the Candida albicans species of fungal pathogen.
The researchers wrote, “Candida albicans is the most common pathogenic fungus isolated in bloodstream infections in hospitalized patients, and the fourth most frequent infection in U.S. hospitals.” They also noted that Candida albicans “has the ability to form biofilms — a community of fungal cells surrounded by a protective matrix that effectively shelters Candida against the action of antifungal drugs.” Because of its ability to form protective biofilms, Candida can be extremely difficult to eradicate with modern antifungal drugs. The researchers decided to test silver nanoparticles to see if they could defeat the biofilm formation of the Candida fungal species, and could therefore be used as an alternative to prescription antifungal drugs.
The study authors concluded, “Our results demonstrate that silver nanoparticles are potent inhibitors of C. albicans biofilm formation. Observations with a Scanning Electron Microscope are consistent with an overall loss of structure of biofilms mostly due to disruption of the outer cell membrane/wall and inhibition of filamentation. Transition Electron Microscopy indicates the permeabilization of the cell wall and subsequent disruption of the structural layers of the outer fungal cell wall. The anti-biofilm effects are via cell wall disruption.” In other words, the silver nanoparticles not only inhibited the formation of Candida biofilms, but they also destroyed existing biofilms by disrupting the outer cell wall of the fungus and entering into the fungal cells.
