Wowk Brian, Ting Alison, Phan John, Pagotan Roberto, Sharif Adnan, Chow Limdo, Fahy Gregory M
21st Century Medicine, Inc., 14960 Hilton Drive, Fontana, CA, 92336, USA.
Gaia Life, Inc. 4401 Leeds Ave, Suite 130, North Charleston, SC, 29405, USA; Expanse Bio LLC, 4401 Leeds Ave, Suite 130, North Charleston, SC, 29405, USA.
Cryobiology. 2025 Jun;119:105257. doi: 10.1016/j.cryobiol.2025.105257. Epub 2025 May 8.
Organs cryopreserved by vitrification benefit from fast warming to avoid growth and recrystallization of ice that may nucleate during cooling and during warming. Rapid warming is especially important for tissue that doesn't absorb the full concentration of perfused cryoprotectants. Nanowarming uses an oscillating magnetic field to heat magnetic nanoparticles introduced into blood vessels during cryoprotectant perfusion. Dielectric warming uses an oscillating electric field to directly heat water and cryoprotectant molecules everywhere inside an organ. The efficiency of dielectric warming peaks at a particular solution viscosity and temperature that depends on the field oscillation frequency. Below that temperature, field uniformity is very important for uniform warming. An 800 W 55 MHz dielectric warming system was constructed that reached peak warming efficiency at -60 °C instead of -70 °C previously observed at 27 MHz when using the M22 vitrification solution. The shape of capacitor plates that formed the electric field for organ warming was optimized by computer simulation. Computer simulation also provided insights into the effects of organ container shape on internal field uniformity, confirming the theoretical prediction that ellipsoidal shapes are optimum. Dielectric materials surrounding the organ container during warming were used with beneficial effect. In physical experiments with constant field warming at 55 MHz, warming rates peaked near 200 °C/min for ∼15 g rabbit kidneys in 45 mL total volume, and near 700 °C/min for ∼5 g porcine ovaries in 15 mL total volume. Of three rabbit kidneys vitrified, dielectrically warmed under slightly varying conditions, and then transplanted, one survived long-term with return to normal clinical function (serum creatinine <2 mg/dL) in the recipient animal still living 17 months later. The mass of the kidney was 13.9 g, by an order of magnitude the largest vitrified vital organ successfully returned to clinically normal function to date.
通过玻璃化冷冻保存的器官受益于快速升温，以避免在冷却和升温过程中可能形成的冰的生长和重结晶。快速升温对于不能吸收灌注的冷冻保护剂全部浓度的组织尤为重要。纳米升温利用振荡磁场加热在冷冻保护剂灌注期间引入血管的磁性纳米颗粒。介电升温利用振荡电场直接加热器官内部各处的水和冷冻保护剂分子。介电升温的效率在特定的溶液粘度和温度下达到峰值，这取决于场振荡频率。低于该温度时，场均匀性对于均匀升温非常重要。构建了一个800 W、55 MHz的介电升温系统，该系统在使用M22玻璃化溶液时，在-60°C时达到峰值升温效率，而不是之前在27 MHz时观察到的-70°C。通过计算机模拟优化了形成器官升温电场的电容器极板形状。计算机模拟还深入了解了器官容器形状对内部场均匀性的影响，证实了椭圆形是最佳形状的理论预测。在升温过程中围绕器官容器使用介电材料产生了有益效果。在55 MHz恒定场升温的物理实验中，对于总体积为45 mL的约15 g兔肾，升温速率在200°C/分钟附近达到峰值，对于总体积为15 mL的约5 g猪卵巢，升温速率在700°C/分钟附近达到峰值。在三个玻璃化的兔肾中，在略有不同的条件下进行介电升温，然后进行移植，其中一个长期存活，受体动物恢复了正常临床功能（血清肌酐<2 mg/dL），该受体动物在17个月后仍然存活。该肾的质量为13.9 g，是迄今为止成功恢复到临床正常功能的最大的玻璃化重要器官，数量级上属于此类。
