Controlled culture of adult human skin: Characterization

Long term growth and differentiation of adult human skin cells has been achieved by more effective control of culture pH, gas phase, osmolarity and nutrient supply at optimized set point values than that possible with conventional batch feed culture. This control was achieved by means of an automatic perfusion, rocker culture apparatus. The following characteristics of these skin cultures particularly lend themselves to application as a source of skin graft material for use in humans requiring large area skin grafts: high culture success rate was achieved in that 12/12 specimens of adult skin exhibited growth to confluence within 4-6 weeks. Cultures demonstrated logarithmic growth for a minimum of 5 weeks, 25-50 fold enhancement in area by 4-6 weeks, 16-fold increase in glucose utilization at 9 weeks, nearly 4-fold increase in total DNA at 5 weeks, and a minimum 6-fold increase in nuclei counts at 5 weeks in culture. The multilayered outgrowth maintained a predominantly epithelial cell composition, but contained normal skin cell types other than keratinocytes, including melanocytes, and dermal fibroblasts, which may be required for long term survival of cultured skin transplanted back to humans. Other than the use of 10% fetal bovine collagen culture medium and denatured bovine collagen substratum, the system did not require heterologous components for plating or growth stimulation. Neither mouse feeder cells, nor the selective pressure of passage were required to obtain growth in surgically useful quantities. This cultured skin is potentially useful as replacement skin for large area wounds such as in burn patients.