Study of the Vascular Endothelial Cell Shape Change during Freezing.

Microvascular injury is recognized as a major tissue damage mechanism of ablative cryosurgery. Details of this injury mechanism are not completely understood. ECMatrix™ 625 was used to mimic the tumor environment and to allow the endothelial cells cultured in vitro to form the tube-like structure of the vasculature. Influences of water dehydration and chilling effects on the endothelial cell and the integrity of the structure during freezing were studied. It was found that the initial cell shape change was mainly controlled by water dehydration, which is dependent on the cooling rate. As the cooling prolonged and temperature lowered, further cell shape change could be induced by chilling effects on intracellular proteins, and focal adhesions to the basement membrane, resulting in the final cell rounding and detachment of endothelial cells in vivo.