IADR Abstract Archives
Na-DNA Mouthwashes Reduce Cell Degeneration: Bioreactor-based Reconstituted Oral Epithelium Model
Objectives: Sodium DNA (Na-DNA) is constituted by purified, depolymerized and neutralized deoxyribonucleic acid extracted from the gonadic tissue of male sturgeons. This study aimed to investigate whether the addition of Na-DNA to a chlorhexidine (CHX)-containing mouthwash influences morphology and viability of Reconstituted human Oral Epithelium (ROE), and protects ROE against oxidative stress.
Methods: Air-lifted, multi-layered 0.5 cm2 ROE coupons (SkinEthic) were positioned inside a continuous-flow bioreactor, grown air-lifted for 24h in supplemented RPMI medium then either treated with (PBS) phosphate-buffered saline or (H) 1 vol% H2O2 for 1 min. Immediately after, coupons were treated for 30 min with mouthwash solutions containing: (A) 0.2% CHX, (B) 0.2% CHX + Na-DNA, (C) Na-DNA, (D) PBS. Coupons were then subjected to tetrazolium-based viability assay, Confocal Laser-Scanning Microscopy (CLSM) imaging, and histological evaluation using optical microscopy and Transmission Electron Microscopy (TEM) imaging.
Results: Viability assay: H-C elicited significantly higher viability than H-D, suggesting a significant protective activity of Na-DNA on cells viability.
CLSM: CHX caused loss of cell junctions in the superficial layer. PBS-C and H-C showed a lower number of dead cells compared to PBS-D and H-D, respectively.
Histological evaluation (Figure 1): CHX and, especially, H2O2-treatment caused alterations of cells structures. PBS-B and especially H-B showed less alterations compared to PBS-A and H-A, respectively. In H-B and H-C some cells not showing degeneration signs were found in the innermost layers, where they were probably more protected from CHX and reactive oxygen species, and where Na-DNA helped in minimizing cell damage.
Conclusions: Na-DNA showed a clear and protective action against cellular degeneration due to oxidative stress and, partly, to the exposure to CHX. Its addition to chlorhexidine mouthrinses or gels could be clinically helpful in contrasting the detrimental activity of CHX on oral tissues, and in supporting preservation of cell viability, control of inflammation and wound healing
Methods: Air-lifted, multi-layered 0.5 cm2 ROE coupons (SkinEthic) were positioned inside a continuous-flow bioreactor, grown air-lifted for 24h in supplemented RPMI medium then either treated with (PBS) phosphate-buffered saline or (H) 1 vol% H2O2 for 1 min. Immediately after, coupons were treated for 30 min with mouthwash solutions containing: (A) 0.2% CHX, (B) 0.2% CHX + Na-DNA, (C) Na-DNA, (D) PBS. Coupons were then subjected to tetrazolium-based viability assay, Confocal Laser-Scanning Microscopy (CLSM) imaging, and histological evaluation using optical microscopy and Transmission Electron Microscopy (TEM) imaging.
Results: Viability assay: H-C elicited significantly higher viability than H-D, suggesting a significant protective activity of Na-DNA on cells viability.
CLSM: CHX caused loss of cell junctions in the superficial layer. PBS-C and H-C showed a lower number of dead cells compared to PBS-D and H-D, respectively.
Histological evaluation (Figure 1): CHX and, especially, H2O2-treatment caused alterations of cells structures. PBS-B and especially H-B showed less alterations compared to PBS-A and H-A, respectively. In H-B and H-C some cells not showing degeneration signs were found in the innermost layers, where they were probably more protected from CHX and reactive oxygen species, and where Na-DNA helped in minimizing cell damage.
Conclusions: Na-DNA showed a clear and protective action against cellular degeneration due to oxidative stress and, partly, to the exposure to CHX. Its addition to chlorhexidine mouthrinses or gels could be clinically helpful in contrasting the detrimental activity of CHX on oral tissues, and in supporting preservation of cell viability, control of inflammation and wound healing
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