IADR Abstract Archives

Direct Effect of N-acetyl Cysteine on HEMA Cytotoxicity

Objective: Many in vitro studies have shown that the polymerization reaction of resin based materials is never complete and non-polymerized monomers, including 2-hydroxy ethyl methacrylate (HEMA), might be released in oral environment causing adverse effects. Recently it has been reported a protective effect of N-acetyl cysteine (NAC) against the cytotoxicity of HEMA and cements containing methacrylic monomers. The aim of our study was to test the hypothesis that the protection of NAC on HEMA cytotoxicity might be due to direct NAC adduct formation. Methods: NAC (10 mmol/L) effect on HEMA cytotoxicity and on extra and intracellular monomer concentration were evaluated in 3T3 fibroblasts. Cells were treated with HEMA (4 and 8 mmol/L) in presence or absence of NAC. After 8 h or 24 h of incubation time, cytosol from fibroblasts and extracellular media were collected and analyzed by HPLC. To unambiguously identify the adduct in fibroblasts, samples were analyzed with Capillary Electrophoresis coupled with mass spectrometry. Data were analyzed using t-Test. Results: NAC reduced HEMA cytotoxicity and monomer extracellular concentration from 4 to 1 mmol/L and from 8 to 3 mmol/L after 8 h of exposition, whereas the monomer levels dropped to 0.6 and 1.66 mmol/L, after 24 h. Intracellular HEMA concentration was reduced from 0.2 mmol/L to 0.12 mmol/L when HEMA (4 mmol/L) was added to the medium in the presence of NAC for 8 h; furthermore, a reduction from 0.45 mmol/L to 0.21 mmol/L was observed with 8 mmol/L HEMA. After 24 h, NAC caused a decrease in the intracellular HEMA levels (2.3-fold and 4.1-fold) when cells were treated with 4 and 8 mmol/L HEMA, respectively. NAC-HEMA adducts were detected both inside and outside cells. Conclusions: Our findings suggest that the in vitro detoxification ability of NAC against HEMA-induced cell damage occurs through NAC adduct formation.
IADR/PER General Session
2010 IADR/PER General Session (Barcelona, Spain)
Barcelona, Spain
2010
206
Dental Materials 5: Biocompatibility and Biologic Effects
  • Nocca, Giuseppina  ( Universita Cattolica del Sacro Cuore, Roma, N/A, Italy )
  • D'anto', Vincenzo  ( University of Naples "Federico II", Naples, N/A, Italy )
  • Desiderio, Claudia  ( Consiglio Nazionale delle Ricerche -ICRM- Sez Roma, Roma, N/A, Italy )
  • Valletta, Rosa  ( University of Naples "Federico II", Naples, N/A, Italy )
  • Schweikl, Helmut  ( University Medical Center Regensburg, Regensburg, N/A, Germany )
  • Lupi, Alessandro  ( Consiglio Nazionale delle Ricerche -ICRM- Sez Roma, Roma, N/A, Italy )
  • Rengo, Sandro  ( University of Naples "Federico II", Naples, N/A, Italy )
  • Spagnuolo, Gianrico  ( University of Naples "Federico II", Naples, N/A, Italy )
  • Oral Session
    Cytotoxicity and Dental Materials
    07/14/2010