Biologic assessment of antiseptic mouthwashes using a three-dimensional human oral mucosal model.

BACKGROUND: The biologic safety profile of oral health care products is often assumed on the basis of simplistic test models such as monolayer cell culture systems. We developed and characterized a tissue-engineered human oral mucosal model, which was proven to represent a potentially more informative and more clinically relevant alternative for the biologic assessment of mouthwashes. The aim of this study was to evaluate the biologic effects of alcohol-containing mouthwashes on an engineered human oral mucosal model. METHODS: Three-dimensional (3D) models were engineered by the air/liquid interface culture technique using human oral fibroblasts and keratinocytes. The models were exposed to phosphate buffered saline (negative control), triethylene glycol dimethacrylate (positive control), cola, and three types of alcohol-containing mouthwashes. The biologic response was recorded using basic histology; a cell proliferation assay; 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tissue-viability assay; transmission electron microscopy (TEM) analysis; and the measurement of release of interleukin (IL)-1beta by enzyme-linked immunosorbent assay. RESULTS: Statistical analysis showed that there was no significant difference in tissue viability among the mouthwashes, cola, and negative control groups. However, exposure to the positive control significantly reduced the tissue viability and caused severe cytotoxic epithelial damage as confirmed by histology and TEM analysis. A significant increase of IL-1beta release was observed with the positive control and, to a lesser extent, with two of the tested mouthrinses. CONCLUSIONS: The 3D human oral mucosal model can be a suitable model for the biologic testing of mouthwashes. The alcohol-containing mouthwashes tested in this study do not cause significant cytotoxic damage and may slightly stimulate IL-1beta release.

Development of biodegradable electrospun scaffolds for dermal replacement.

Our objective is to develop a synthetic biodegradable replacement dermal substitute for tissue engineering of skin and oral mucosa. Our in vivo criteria were that candidate scaffolds should allow surrounding cells to migrate fully into the scaffolds, enabling vasculogenesis and remodelling without invoking a chronic inflammatory response. We examined a total of six experimental electrospun polymer scaffolds: (1) poly-l-lactide (PLLA); (2) PLLA+10% oligolactide; (3) PLLA+rhodamine and (4-6) three poly(d,l)-lactide-co-glycolide (PLGA) random multiblock copolymers, with decreasing lactide/glycolide mole fractions (85:15, 75:25 and 50:50). These were evaluated for degradation in vitro up to 108 days and in vivo in adult male Wistar rats from 4 weeks to 12 months. In vivo, all scaffolds permitted good cellular penetration, with no adverse inflammatory response outside the scaffold margin and with no capsule formation around the periphery. The breakdown rate for each scaffold in vitro versus in vivo was similar, and an increase in the ratio of polyglycolide to polylactide correlated with an increase in breakdown rate, as expected. Scaffolds of PLLA were stable in vivo even after 12 months whereas scaffolds fabricated from PLGA 85:15 and 75:25 revealed a 50% loss of mass after 4 and 3 months, respectively. In vitro PLGA 85:15 and 75:25 scaffolds were able to support keratinocyte, fibroblast and endothelial cell growth and extracellular matrix production, with evidence of new collagen production after 7 days. In conclusion, the data supports the development of PLGA 85:15 and 75:25 electrospun polymer scaffolds as potential degradable biomaterials for dermal replacement.