Device Design for the Rapid Ultrasonic Rewarming of Alginate Beads and Cryoprotectant Solution to Improve Cryopreservation Recovery

Ultrasonic rewarming is a new method for improving cryopreservation recovery. We developed an ultrasonic rewarming device and control algorithm for the rapid and repeatable rewarming of cryopreserved biological media in cryovials. We characterised the device’s acoustic output with hydrophone measurements and rewarming rates with thermocouple measurements. Mean rewarming rates of 120°C/min were achieved with cryopreserved alginate beads and cryoprotectant solution. The ultrasound exposures implemented free-field pressure amplitudes in the 3 MPa range, corresponding to 100 W electrical absorbed power. The exposure duration timing was accurate to ~0.5 s. The device will provide a platform for ultrasonic rewarming cell viability studies.