OPTIMIZED GROWTH-MEDIUM FOR PRIMARY CULTURE OF HUMAN ORAL KERATINOCYTES

The effect of different media additives in defining optimal growth con ditions for primary cultures of human oral keratinocytes was studied. A cocultivation technique with irradiated Swiss-3T3-fibroblasts in 96- well plates enables the comparison of additives for primary keratinocy te cultures derived from one patient. H-3-labeled thymidine uptake sho wed no growth or growth inhibition with adenine, choleratoxin or trans ferrin compared to basal medium (Dulbecco's modified Eagle's medium (D MEM) and 10% fetal calf serum). Among single additives, 5 mu g/ml hydr ocortisone, 5 mu g/ml insulin, 10 ng/ml EGF, 2 mu g/ml bovine pituitar y extract, and 10(-9) M triiodothyronine showed the greatest capacity to promote keratinocyte growth. With all possible combinations of addi tives, maximum stimulation was found with a combination of EGF (10 ng/ ml), insulin (5 mu g/ml), and hydrocortisone (5 mu g/ml); none of the other combinations were more effective. Our data indicate that in shor t-term cultures (up to 5 days) various media additives described in th e literature are not necessarily required in this system of primary cu lture of human oral keratinocytes.