Investigation on the thermal performance of a novel microchannel-aided device for vitrification of cells/tissues

Among the cryopreservation technologies, vitrification has displayed significant advantages compared to the traditional methods. To obtain the desired cooling/rewarming rates for vitrification, recent approaches tend to minimize sample volume and thereby lower the inner thermal resistance. However, those approaches also lead to practical limitations in throughput and applicable sample types. To address the problems, we developed a novel device based on microchannel heat transfer to accomplish vitrification for various sizes of samples. An operation system was also developed to drive and control the flow of cooling media (liquid nitrogen) or rewarming media (warm aqueous alcoholic solution) in the microchannels. Theoretical and experimental investigations were performed to evaluated the thermal performance of the device. It was demonstrated that the device incorporated with the operation system achieved highly efficient heat exchange with the sample solution in both cooling and rewarming. The ultra-high cooling/rewarming rates (26,000-55,267 °C/min) and flexible volume capacity (15-295 μl) make the device possible to vitrify more types of cells or small tissues (like skin and cornea) which cannot be treated with the existing minimum-volume approaches. With such significant breakthrough, the presented device provides a paradigm shift approach for cryopreservation through vitrification.