title: Protective effect of chitosan oligosaccharide lactate against DNA double-strand breaks induced by a model methacrylate dental adhesive.
abstract: BACKGROUND
  Monomers of methacrylates used in restorative dentistry have been recently reported to induce DNA double-strand breaks (DSBs) in human gingival fibroblasts (HGFs) in vitro. Because such monomers may penetrate the pulp and oral cavity due to the incompleteness of polymerization and polymer degradation, they may induce a similar effect in vivo. DSBs are the most serious type of DNA damage and if misrepaired or not repaired may lead to mutation, cancer transformation and cell death. Therefore, the protection against DSBs induced by methacrylate monomers released from dental restorations is imperative.
  
  
  METHODS
  We examined the protective action of chitosan oligosaccharide lactate (ChOL) against cytotoxic and genotoxic effects induced by monomers of the model adhesive consisting of 55% bisphenol A-diglycidyl dimethacrylate (Bis-GMA) and 45% 2-hydroxyethyl methacrylate (HEMA). We evaluated the extent of DSBs by the neutral comet assay and the phosphorylation of the H2AX histone test.
  
  
  RESULTS
  ChOL increased the viability of HGFs exposed to Bis-GMA/HEMA as assessed by flow cytometry. ChOL decreased the extent of DSBs induced by Bis-GMA/HEMA as evaluated by neutral comet assay and phosphorylation of the H2AX histone. ChOL did not change mechanical properties of the model adhesive, as checked by the shear bond test. Scanning electron microscopy revealed a better sealing of the dentinal microtubules in the presence of ChOL, which may protect pulp cells against the harmful action of the monomers.
  
  
  CONCLUSIONS
  ChOL can be considered as an additive to methacrylate-based dental materials to prevent DSBs induction, but further studies are needed on its formulation with the methacrylates.
authors.affiliation: Department of Developmental Dentistry, Medical University of Lodz, Lodz, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Szczepanska
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Pawlowska
authors.forename: Ewelina
authors.initials: E
authors.lastname: Synowiec
authors.forename: Piotr
authors.initials: P
authors.lastname: Czarny
authors.forename: Marek
authors.initials: M
authors.lastname: Rekas
authors.forename: Janusz
authors.initials: J
authors.lastname: Blasiak
authors.forename: Jacek Pawel
authors.initials: JP
authors.lastname: Szaflik
mesh_terms: D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D004247:DNA / Q000187:drug effects*; D053903:DNA Breaks, Double-Stranded; D003738:Dental Cements / Q000633:toxicity*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D005881:Gingiva / Q000166:cytology; D006657:Histones / Q000378:metabolism; D006801:Humans; D007773:Lactates / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D008689:Methacrylates / Q000737:chemistry / Q000633:toxicity*; D015394:Molecular Structure; D009844:Oligosaccharides / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D033081:Shear Strength
chemical_list: D003738:Dental Cements; C468783:H2AX protein, human; D006657:Histones; D007773:Lactates; D008689:Methacrylates; D009844:Oligosaccharides; D017438:Bisphenol A-Glycidyl Methacrylate; C005044:hydroxyethyl methacrylate; D004247:DNA; D048271:Chitosan