IMPROVED METHOD FOR HARVESTING HUMAN SCHWANN-CELLS FROM MATURE PERIPHERAL-NERVE AND EXPANSION IN-VITRO

The use of cellular prostheses containing large populations of Schwann cells (SC) has been proposed as a future therapeutic approach in the repair of neural tissue. We have sought to define an efficient protoco l for the harvest and expansion of human SC from mature human peripher al nerve. We evaluated SC proliferation occurring within fresh explant s and studied the relationship between certain parameters (cell yield, purity, and rate of SC proliferation) and the conditions of maintenan ce of nerve explants prior to dissociation. In addition, we studied SC proliferation after dissociation in a variety of conditions. We obser ved that SC within explants divide at a low rate during the first 3 we eks following explantation; this proliferation falls to near zero duri ng the fourth week. The cell yield, SC purity, and proliferation rate following dissociation were all increased when nerve explants were exp osed to heregulin/forskolin for 2 weeks prior to dissociation. Electro n microscopic analysis showed that heregulin/forskolin exerted trophic effects on SC within explants. Following dissociation, SC growth in h eregulin/forskolin-containing medium was more rapid on laminin or coll agen than on poly-L-lysine. These results provide new insights into hu man SC biology and suggest several procedural improvements for harvest ing and expanding these cells. The new method we describe shortens our previous procedure by 4-6 weeks and provides a 30-50-fold increase in the number of SC obtained relative to the earlier procedure. (C) 1996 Wiley-Liss, Inc.