Effect of tetracyclines in organotypic cocultures using human gingival epithelial cells and human periodontal ligament fibroblasts

The effects of tetracyclines in organotypic cocultures using human gingival epithelial cells (NDUSD-1 cells) and human periodontal ligament fibroblasts (Pelt cells) were investigated. The organotypic cocultures were treated with tetracycline (TC) or minocycline (MINO) at 10-300ƒÊM for 1 week and multilayered epithelial cells were examined by hematoxylin-eosin staining and immunohistochemistry. Treatment with TC at 30ƒÊM did not affect multilayer formation of epithelial cells, but the formation was inhibited by treatment with TC at 100ƒÊM or more. Treatment with MINO at 10ƒÊM did not affect the multilayer formation, but the formation was inhibited by treatment with MINO at 30 ƒÊM or more. These values were greater than their MIC90 concentrations for periodontopathic bacteria, including Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans. These results suggested that topical administration of TC or MINO to the periodontal pocket at their MIC90 concentration for periodontopathic bacteria would have few adverse effects on the growth of the periodontal ligament.