Biological responses of human gingival fibroblasts (HGFs) in an innovative co-culture model with Streptococcus mitis to thermosets coated with a silver polysaccharide antimicrobial system

PLoS One. 2014 May 7;9(5):e96520. doi: 10.1371/journal.pone.0096520. eCollection 2014.

Abstract

This study sought to evaluate the in vitro biological response of human gingival fibroblasts (HGFs) co-coltured with Streptococcus mitis to bisphenol A glycidylmethacrylate/triethylene glycol dimethacrylate (BisGMA/TEGDMA) thermosets coated with Chitlac-nAg, a nanocomposite system with antimicrobial properties. To avoid bacterial adhesion to dental devices and to reduce cytotoxicity against eukaryotic cells, we coated BisGMA/TEGDMA methacrylic thermosets with a new material, Chitlac-nAg, formed by stabilizing silver nanoparticles, which have well-known antimicrobial properties, with a polyelectrolyte solution containing Chitlac. Cytotoxicity, cell morphology, cell migration and inflammatory interleukine-6 (IL-6) and prostaglandin E2 (PGE2) secretion were evaluated. Our results showed that the cytotoxicity exerted on HGFs by our nanocomposite material was absent in our co-culture model, where fibroblasts are able to adhere and migrate. After 24 h thermosets coated with Chitlac as well as those coated with Chitlac-nAg exerted a minimal cytotoxic effect on HGFs, while after 48 h LDH release rises up 20%. Moreover the presence of S. mitis reduced this release in a greater amount with Chitlac-nAg coated thermosets. The secretion of IL-6 was significant in both Chitlac and Chitlac-nAg coated thermosets, but PGE2 production was minimal, suggesting that the IL-6 production was not related to an inflammatory response. Co-culture and the addiction of saliva did not influence IL-6 and PGE2 secretion. Data obtained in the present work suggest that Chitlac n-Ag coated thermosets could significantly improve the success rates of restorative dentistry, since they limit bacterial adhesion and are not toxic to HGFs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / pharmacology*
  • Cell Movement / drug effects
  • Cell Survival / drug effects*
  • Coculture Techniques
  • Dinoprostone / metabolism
  • Fibroblasts / cytology
  • Fibroblasts / drug effects*
  • Fibroblasts / metabolism
  • Gingiva / cytology
  • Gingiva / drug effects*
  • Gingiva / metabolism
  • Humans
  • Interleukin-6 / metabolism
  • Nanocomposites
  • Silver Compounds / pharmacology*
  • Streptococcus mitis / drug effects*

Substances

  • Anti-Infective Agents
  • Interleukin-6
  • Silver Compounds
  • Dinoprostone

Grants and funding

This work was supported by a number of sources: first, a FIRB project, -“Accordi di Programma 2010”, directed by Prof. Cataldi (Cod.RBAPI095), on ‘Processi degenerativi dei tessuti mineralizzati del cavo orale, impieghi di biomateriali e controllo delle interazioni con microrganismi dell’ambiente’, second Prof. Cataldi’s 2009 PRIN grant entitled ‘Ruolo delle protein chinasi C (PKC) nei processi di interazione/integrazione tra biomateriale dentale/tessuto ospite/flora microbica della cavita’ orale’, third, an “ex 60%” grant held by Prof. Cataldi and fourth, an “ex 60%” grant held by Dr. Viviana di Giacomo. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.