ORGANOTYPIC HUMAN ORAL TISSUE MODELS FOR TOXICOLOGICAL STUDIES.

This study by researchers at Procter & Gamble Co., the University of Iowa and MatTek Corp. demonstrated that MatTek’s EpiOral and EpiGingival human oral cavity tissue equivalents can be used to screen the irritation potential of newly developed oral care products and will be useful to study the innate immunity, biology and pathology of the oral mucosa. Three-dimensional models of the human oral epithelia have been developed by MatTek Corp. to test the irritation of oral-care products and to provide systems to study the pathology of the oral cavity. The in vitro tissue models, cultured using normal oral epithelial cells and serum free medium, adopt a buccal (EpiOral) or gingival (EpiGingival) phenotype. The buccal tissue (designated EpiOral ORL-200) is 8–12 cell layers thick and non-cornified; the gingival tissue (designated EpiGingival GIN-100) is 9–13 layers thick and cornified at the apical surface. The tissues express cytokeratins 13 and 14, similar to their corresponding native oral tissues. The MTT viability assay was used to assess inter-lot and intra-lot reproducibility. The MTT average intra-lot coefficient of variation (CV) was less than 10% for both tissues and the time required to reduce tissue viability by 50% (ET-50) following application of 1% Triton-X 100 averaged 1.02±0.33 h (n=26) and 7.97±0.80 h (n=14) for the buccal and gingival tissues, respectively. The utility of the EpiOral buccal tissue for irritation studies was examined by researchers at Procter & Gamble Co., the University of Iowa and MatTek Corp. by testing prototype dentifrice formulations and commercially available products including mouthwashes, toothpastes, and oral cleansers. Use of the MTT ET-50 assay and cytokine release clearly differentiated between the formulations and the oral care products. In conclusion, MatTek’s EpiOral and EpiGingival oral tissue models represent highly reproducible, non-animal means to screen the irritation potential of newly developed oral care products and should be useful to study the innate immunity, biology, and pathology of the oral mucosa.

Buccal phenotype, Buccal tissue, Cytokeratins 13 and 14, Dentifrice formulations, EpiOral, GIN-100, Gingival phenotype, Gingival tissue, Highly reproducible, non-animal, Human oral epithelia, Innate immunity, Inter-lot reproducibility, Intra-lot reproducibility, Irritation of oral-care products, Irritation potential, Irritation studies, MTT, MTT tissue viability assay, Mouthwashes, Normal oral epithelial cells, ORL-200, Oral care products, Oral cleansers, Oral mucosa, Pathology of the oral cavity, Serum free medium, Three-dimensional models, Toothpastes