Freezing with a magnetic field prevents frostbite in mouse hind legs

Objective: The aim of the present study was to evaluate the effects of frostbite on feet using Cell Alive System (CAS) freezer with an oscillating magnetic field. We recently reported the application of the CAS freezer to the cryopreservation of various tissues, but did not evaluate the effects of frostbite after freezing. In order to characterize how a freezer with a magnetic field affects frostbite, we observed changes using laser Doppler blood flow measurements, X-ray imaging, and tissue specimens from mouse feet. Methods: Mice were divided into 3 groups: a group without freezing, a group in which a foot was frozen in the bath of the CAS freezer for 10 minutes, with preliminary cooling to -32°C using ethylene glycol, and a group in which a foot was frozen by holding it under dry ice for 10 minutes. Results: The results obtained showed that the CAS freezer inhibited freezing-induced damage of the cell cytoskeleton and circulatory disorders 10 days after freezing. Furthermore, the CAS freezer reduced bone deformation after freezing. Conclusions: These results suggest that the CAS freezer prevented frostbite associated with tissue freezing. These rose it’s may potentially lead to the development of novel methods for cryopreservation.