Theoretical investigation of a novel microwave antenna aided cryovial for rapid and uniform rewarming of frozen cryoprotective agent solutions

Abstract

The most challenging issue in cryopreservation of mass biomaterials is to rewarm the frozen sample in a fast and uniform manner, so that the dangerous devitrification and recrystallization may be avoided. In this study, a conceptual innovation is the design of a novel cryovial, and we investigate the effects of the microwave heating after embedding superparamagnetic nanoparticles on the rewarming processes of the cell suspensions encapsulated in the cryovial. The electromagnetic field and the heat transfer during the hybrid rewarming processes of frozen EC2 solution with temperature-dependent properties were calculated. During the rewarming process of the sample in the cryovial in a traditional 37 °C water bath, the rewarming rate was 72.15 °C/min and the maximum temperature gradient in the sample was 20.5 °C/mm. After a slot antenna was included in the cryovial, the rewarming rate was 83.71 °C/min without nanoparticles and 106.41 °C/min after nanoparticles are embedded, the maximum temperature gradient in the sample was 40.2 °C/mm without nanoparticles and 28.7 °C/mm after nanoparticles embedded, respectively. This indicates that the rewarming rate and the uniformity of the temperature distribution increased after embedding nanoparticles. This could be because nanoparticles homogeneously generate heat in the sample and improve the time-dependent parameters of the sample.