PROLONGED MAINTENANCE OF HUMAN HAIR-FOLLICLES IN-VITRO IN A SERUM-FREE MEDIUM

We have previously reported the in vitro growth of human hair follicle s for up to 4 days in a partially defined medium containing serum. We now report the prolonged in vitro growth of isolated human hair follic les for at least 9 days. This was achieved after analysis of the contr ibution of certain components of the original medium and, by a process of elimination, deriving a completely defined medium supplemented onl y with antibiotics, L-glutamine, insulin and hydrocortisone. We have s hown, by [methyl-H-3] thymidine autoradiography, that the hair follicl es grown in this medium maintain an in vivo pattern of DNA synthesis, and that the gross morphology and histology of these maintained hair f ollicles remains similar to that of freshly isolated hair follicles. W e have also shown that the patterns of keratin synthesis, as determine d by [S-35] methionine labelling, do not alter with maintenance.