HUMAN FETAL CORTICAL TISSUE FRAGMENTS SURVIVE GRAFTING FOLLOWING ONE WEEK STORAGE AT -DEGREES-C(4)

Grafting of human fetal tissue fragments has been used successfully in experimental and clinical trials. The development of techniques to st ore human fetal tissue fragments for longer time periods mould allow t o establish temporary tissue banks. We dissected several human cortica l tissue fragments from one fetus and tested different storage conditi ons (cooling, freezing, culturing). After storage, the tissue fragment s were transplanted into cavities in the cortex of host rats and the v olume of the surviving grafts calculated. We report that human cortica l tissue fragments grafted immediately after dissection (control group ) or grafted after storage for 3 h in cryopreservation medium at room temperature survived grafting and resulted in graft sizes of 102 +/- 2 6 mm(3) and 242 +/- 210 mm(3), respectively, however, statistically no t different. When the human cortical tissue fragments were slowly froz en and stored for 1 wk and/or when the fragments were cultured for 1 w eek in culture medium using a roller tube technique, grafts did not su rvive under our conditions. However, when the human cortical tissue fr agments were stored for 1 week at +4 degrees C in cryopreservation med ium, the graft size (48 +/- 24 mm(3)) was reduced but statistically no t different from the control group. We conclude that human cortical ti ssue fragments can be stored at +4 degrees C for at least 1 wk without major loss of ability to survive grafting.