INVITRO CULTIVATION OF HUMAN ORAL KERATINOCYTES

The technique of Rheinwald and Green (1975b) for the serial cultivation of foreskin keratinocytes was modified to facilitate the cultivation of gingival and buccal keratinocytes. We used 7-10-day epithelial outgrowths from excised tissue fragments as a source of keratinocytes, whereas Rheinwald and Green used enzymically-dissociated keratinocytes from freshly obtained foreskin. Mitomycin-C treatment as opposed to gamma irradiation was used to suppress the growth of fibroblast feeder layers. Single oral keratinocytes proliferated to form colonies resembling a stratified squamous epithelium. Light and electron microscopy revealed structures usually associated with epithelia, i.e. desmosomes, tonofilaments, tonofibrils, thickened cell membranes and a glycocalyx on the free surface of the epithelium. Oral keratinocytes underwent 20-40 doublings before senescence. © 1979.