Sukhach O. Low temperature preservation of neural progenitor cells in multicellular aggregates.

The research object was the cultivation of neural cells before and after cryopreservation and hypothermic storage. The aim was to determine conditions for multicellular aggregate formation by human and rat isolated brain cells in the culture, to examine the impact of aggregate formation on biological characteristics of neural progenitors after cryopreservation and hypothermic storage, to study the efficiency of transplantation of neural progenitors within aggregates to rats with traumatic spinal cord injury. Methods: isolation of cells, cultivation, cryopreservation, light and fluorescent microscopy, morphometric analysis, immunocytochemistry, spectrophotometry, biochemical methods, methods of statistical analysis. There were first determined the principal factors of multicellular aggregate spontaneous formation during culturing of isolated neural cell heterogeneous suspension. For the first time there were obtained the original data, showing in aggregates the favorable conditions for proliferation and differentiation of neural progenitors as established in the absence of exogenous growth factors, cytokines and hormones. It was first shown that neural progenitor cells within aggregates retained the ability to proliferate and differentiate with longer terms of hypothermic storage in contrast with neural progenitors in suspensions. The isolated neural progenitor cells within aggregates were first demonstrated as characterized by a higher cryoresistance compared with cells in suspensions.In experimental models of rats with spinal cord injury it was first shown that transplantation of cryopreserved neural progenitor cells within aggregates had a more pronounced positive effect on recovery of hind limb mobility than transplantation of cells in suspension. The findings can be used to design new and improve the existing protocols of cultivation and low temperature storage, for selection of viable isolated neural progenitor cells as well.