Growth of Porcine Enamel-,Dentin-,and Cementum-Derived Cells in Collagen-Glycosaminoglycan Matrices in Vitro : Expression of α -Smooth Muscle Actin and Contraction

Abstract

The objective of the study was to investigate the behavior of porcine enamel, dentin, and cementum cells, isolated from tissue digests and growing out from explants, in monolayer culture and in a collagen-glycosaminoglycan (GAG) matrix for tissue engineering. A notable finding of the study was the expression of a contractile muscle actin isoform, α-smooth muscle actin (SMA), by each cell type and their contraction of the collagen-GAG scaffold. Of importance was the immunohistochemical demonstration that the majority of ameloblasts and odontoblasts in vivo contained SMA. Western blot analysis demonstrated the presence of SMA in all of the cell types. A large amount of SMA was found in the odontoblasts after the first passage. SMA expression in the enamel- and cementum-derived cells appeared to increase with time in culture and with passage number. The implications of this finding for tissue engineering and the possible roles for SMA in dental tissue cells are discussed.