Enhancement Of Cryoinjury By Use Of Eutectic Crystallization Of An Amino Acid Adjuvant
Abstract
Enhancement of cryoinjury by use of eutectic formation was investigated to improve the efficacy of cryosurgery. Although the enhancement of cryoinjury associated with eutectic crystallization of sodium chloride (NaCl) has been demonstrated, its advantage can be maximized with adjuvants which are biocompatible and have higher eutectic temperature than NaCl. In this study, the feasibility of glycine, which is less toxic and have higher eutectic temperature than NaCl, was tested. Two groups of MCF-7 human breast cancer cell were suspended in isotonic saline with glycine, then were frozen and thawed on a directional solidification stage in the same protocol except that eutectic crystallization was initiated in only one group. The results show that the post-thaw viability drops from 86% to 38.6% upon the initiation of eutectic crystallization at a high temperature (-8.5°C). The results also confirm that enhancement of direct cell injury during freezing can be achieved by eutectic crystallization.