A Critical Review on Cryopreservation of Cells Technics: Thermal Aspects

Abstract

The studies carried out in the area of cell preservation have been of significant importance in recent years. This process, known as cryopreservation, has been used for decades and aims to preserve various cellular materials at cryogenic temperatures. Different methods allow cryopreservation, where the best known are the slow freezing and vitrification processes. Regardless of the process, it is necessary to use cryoprotective agents (CPAs) in conjunction with the cells to avoid possible cell damage during cryopreservation. Regarding the methods, they differ in their cooling rates and the concentration of CPAs used. According to some studies, the method that has been most studied is that of vitrification, which seeks to increase the cooling rate, reaching values above 20,000 ∘ C/min. Evaporation by a thin film of liquid nitrogen is one of the methods of vitrification, which uses a microstructure with a finned or porous surface for evaporation, and in these conditions cooling rates of up to 150,000 ∘ C/min were found, which shows a significant advance and alternative for cell cryopreservation.