Physical demonstration of vitrification of liter scale CPA systems and characterization of 120KW RF coil for nanowarming of liter scale systems

Organ cryopreservation by vitrification and rewarming have been demonstrated at size scales up to 50 mL in varied organ systems from rat organs (kidney, heart, and liver) to rabbit kidneys. The next step towards preservation of human organs requires scale-up of the vitrification and rewarming techniques (e.g. liter scale and greater). Vitrification is generally achieved through convective cooling which is size dependent and therefore cooling rates are lower internally as the size increases, which can be a major challenge for vitrification of clinical scale organs. This study demonstrates the vitrification of litre-scale volumes (0.5L, 1L and higher) of VS55, M22, and 40%EG-0.6M-sucrose. Nanowarming on the other hand is based upon volumetric heating and is size independent due to its ability to generate heat via magnetic material (iron-oxide nanoparticles) perfused throughout the organ vasculature, as opposed to convective warming where the heat flux is fixed at the boundary. The concentration of these magnetic nanoparticles can be adjusted for achieving higher and sufficient heating at large volumes. These liter volumes of CPAs can be rewarmed uniformly & rapidly using a state-of-art 120KW radiofrequency (RF) coil with magnetic field strengths variable from 0 to 34 KA/m at 360 KHz and having the capacity to uniformly heat volumes up to 2.5L. The magnetic field generated inside the coil is investigated for uniformity along the axial and radial directions along with the characterization/calibration of the field strength versus system power. This study demonstrates critical milestones for scale-up (multi-liter) vitrification and rewarming of biological material and hence moving towards preservation of human organs.