title: Silver colloidal nanoparticles: effect on matrix composition and structure of Candida albicans and Candida glabrata biofilms.
abstract: OBJECTIVE
  The aim of this study was to assess the effect of different silver nanoparticles (SN) concentrations on the matrix composition and structure of Candida albicans and Candida glabrata biofilms.
  
  
  RESULTS
  Candida biofilms were developed in 6-well microtiter plates during 48 h. After, these biofilms were exposed to 13.5 or 54 μg SN ml(-1) for 24 h. Then, extracellular matrices were extracted from biofilms and analysed chemically in terms of proteins, carbohydrates and DNA. To investigate the biofilm structure, scanning electron microscopy (SEM) and epifluorescence microscopy were used. SN interfered with the matrix composition of Candida biofilms tested in terms of protein, carbohydrate and DNA, except for the protein content of C. albicans biofilm. By SEM, Candida biofilms treated with SN revealed structural differences, when compared with the control groups. Further, SN showed a trend of agglomeration within the biofilms. Epifluorescence microscopy images suggest that SN induced damage on cell walls of the Candida isolates tested.
  
  
  CONCLUSIONS
  In general, irrespective of concentration, SN affected the matrix composition and structure of Candida biofilms and these findings may be related to the mechanisms of biocide action of SN.
  
  
  CONCLUSIONS
  This study reveals new insights about the behaviour of SN when in contact with Candida biofilms. SN may contribute to the development of therapies to prevent or control Candida infections.
authors.affiliation: Department of Dental Materials and Prosthodontics, Araçatuba Dental School, Univ Estadual Paulista (UNESP), Araçatuba/São Paulo, Brazil.
authors.forename: D R
authors.initials: DR
authors.lastname: Monteiro
authors.forename: S
authors.initials: S
authors.lastname: Silva
authors.forename: M
authors.initials: M
authors.lastname: Negri
authors.forename: L F
authors.initials: LF
authors.lastname: Gorup
authors.forename: E R
authors.initials: ER
authors.lastname: de Camargo
authors.forename: R
authors.initials: R
authors.lastname: Oliveira
authors.forename: D B
authors.initials: DB
authors.lastname: Barbosa
authors.forename: M
authors.initials: M
authors.lastname: Henriques
mesh_terms: D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002176:Candida albicans / Q000187:drug effects* / Q000254:growth & development; D041221:Candida glabrata / Q000187:drug effects* / Q000254:growth & development; D002241:Carbohydrates / Q000032:analysis; D002473:Cell Wall / Q000187:drug effects / Q000648:ultrastructure; D004271:DNA, Fungal / Q000032:analysis; D005656:Fungal Proteins / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D012834:Silver / Q000494:pharmacology*
chemical_list: D002241:Carbohydrates; D004271:DNA, Fungal; D005656:Fungal Proteins; D012834:Silver