title: Silver-polysaccharide antimicrobial nanocomposite coating for methacrylic surfaces reduces Streptococcus mutans biofilm formation in vitro.
abstract: OBJECTIVE
  The aim of this study was to determine the in vitro microbiological performances of a lactose-modified chitosan (Chitlac) coating inside which silver nanoparticles were embedded (Chitlac-nAg) for BisGMA/TEGDMA methacrylic specimens.
  
  
  METHODS
  Different concentrations of nAg inside Chitlac coating were tested (1 mM, 2 mM, 5 mM). Specimen surface was analyzed by means of field-emission scanning electron microscopy (FEISEM) and energy-dispersive X-ray spectroscopy (EDS). A 48 h monospecific Streptococcus mutans biofilm was developed over the specimen surfaces using a modified drip-flow bioreactor; adherent viable biomass was assessed by MTT test and biofilm was imaged by confocal laser-scanning microscopy (CLSM).
  
  
  RESULTS
  The presence of finely dispersed nanoparticles inside the Chitlac coating was confirmed by FEISEM and EDS analysis. All nanoparticles were embedded in the Chitlac coating layer. Chitlac-nAg coatings were able to significantly decrease biofilm formation depending on the nAg concentration, reaching a -80% viable biomass decrease when the 5 mM nAg-Chitlac group was confronted to non-coated control specimens. CLSM analysis did not provide evidence of a contact-killing activity, however the antibacterial Chitlac-nAg coating was able to alter biofilm morphology preventing the development of mature biofilm structures.
  
  
  CONCLUSIONS
  The microbiological model applied in this study helped in assessing the antibacterial properties of a coating designed for methacrylate surfaces.
  
  
  CONCLUSIONS
  A microbiological model based on a bioreactor-grown biofilm is useful for preliminary in vitro tests of dental materials. In translational terms, an antibacterial nanocomposite coating based on Chitlac-nAg and designed to be applied to methacrylic surfaces may be a promising way to obtain dental materials able to actively prevent secondary caries.
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, IRCCS Galeazzi Institute, University of Milan, via R. Galeazzi, 4, 20133 Milan, Italy; Department of Medical Sciences, University of Trieste, Piazza dell'Ospitale, 1, 34125 Trieste, Italy. Electronic address: andreiionescu_40@hotmail.com.
authors.forename: A C
authors.initials: AC
authors.lastname: Ionescu
authors.affiliation: Department of Biomedical, Surgical and Dental Sciences, IRCCS Galeazzi Institute, University of Milan, via R. Galeazzi, 4, 20133 Milan, Italy. Electronic address: eugenio.brambilla@unimi.it.
authors.forename: E
authors.initials: E
authors.lastname: Brambilla
authors.affiliation: Department of Life Sciences, University of Trieste, via Giorgieri 5, 34127 Trieste, Italy. Electronic address: atravan@units.it.
authors.forename: A
authors.initials: A
authors.lastname: Travan
authors.affiliation: Department of Medical Sciences, University of Trieste, Piazza dell'Ospitale, 1, 34125 Trieste, Italy. Electronic address: emarsich@units.it.
authors.forename: E
authors.initials: E
authors.lastname: Marsich
authors.affiliation: Department of Life Sciences, University of Trieste, via Giorgieri 5, 34127 Trieste, Italy. Electronic address: idonati@units.it.
authors.forename: I
authors.initials: I
authors.lastname: Donati
authors.affiliation: Department of Earth, Life and Environmental Sciences (DiSTeVA), University of Urbino, Via Ca' Le Suore 2/4, 61029 Urbino (PU) - Italy. Electronic address: pietro.gobbi@uniurb.it.
authors.forename: P
authors.initials: P
authors.lastname: Gobbi
authors.affiliation: Department of Medical Sciences, University of Trieste, Piazza dell'Ospitale, 1, 34125 Trieste, Italy. Electronic address: gturco@units.it.
authors.forename: G
authors.initials: G
authors.lastname: Turco
authors.affiliation: Department of Medical Sciences, University of Trieste, Piazza dell'Ospitale, 1, 34125 Trieste, Italy. Electronic address: rdilenarda@units.it.
authors.forename: R
authors.initials: R
authors.lastname: Di Lenarda
authors.affiliation: Department of Medical Sciences, University of Trieste, Piazza dell'Ospitale, 1, 34125 Trieste, Italy. Electronic address: mcadenaro@units.it.
authors.forename: M
authors.initials: M
authors.lastname: Cadenaro
authors.affiliation: Department of Life Sciences, University of Trieste, via Giorgieri 5, 34127 Trieste, Italy. Electronic address: paolese@units.it.
authors.forename: S
authors.initials: S
authors.lastname: Paoletti
authors.affiliation: Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via San Vitale, 59, 40125 Bologna, Italy. Electronic address: lorenzo.breschi@unibo.it.
authors.forename: L
authors.initials: L
authors.lastname: Breschi
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000737:chemistry; D018441:Biofilms / Q000187:drug effects*; D019149:Bioreactors; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003731:Dental Caries / Q000517:prevention & control; D003764:Dental Materials; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry; D008689:Methacrylates / Q000008:administration & dosage* / Q000737:chemistry; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D053761:Nanocomposites / Q000008:administration & dosage* / Q000737:chemistry; D011134:Polysaccharides / Q000008:administration & dosage* / Q000737:chemistry; D012834:Silver / Q000008:administration & dosage* / Q000737:chemistry; D013295:Streptococcus mutans / Q000187:drug effects* / Q000502:physiology*; D013499:Surface Properties
chemical_list: D000900:Anti-Bacterial Agents; D020099:Coated Materials, Biocompatible; D003764:Dental Materials; D008689:Methacrylates; D011134:Polysaccharides; D012834:Silver
keywords: Biofilm; Bioreactors; Nanocomposite; Silver nanoparticles; Streptococcus mutans