علماء ينجحون في إعادة كلى خنزير للعمل بعد تجميدها ﻷكثر من عام

Scientists have demonstrated a new technique that allows kidneys to be stored for over a year in a freezer and then re-animated. It was demonstrated on "human sized" kidneys from a pig. h/t @kaimicahmills Here's how process works, at a high level: The kidneys were perfused with a cryoprotectant to prevent freezing. It consisted of DMSO, ethlyene glycol, proplyene glycol, X-1000, and Z-1000. They also perfused the kidney with silica-coated iron oxide nanoparticles. The main artery, vein and ureter were then flushed with a more dilute suspension, and the kidney was bagged in that dilute solution. The bag and kidney was frozen solid. The water did not crystallize, it formed vitreous "glassy" "ice". The kidneys were stored at −150 °C (−238 °F). One kidney was stored for 366 days, just over a year. To reheat the kidneys fast they used a 120-kW induction coil running at 360 kHz. High power electromagnetic alternating electric fields make the magnetic nanoparticles generate heat. Reheating proceeds through two stages: Stage 1: 50% power for 90 s, warming from −150 °C to about −120 °C (~23 °C/min). Stage 2: 95% power, driving the organ rapidly through the danger zone where ice can form on rewarming (~32 C/min) Next, within 2 minutes, the kidney is reconnected to the "perfusion circuit" and the cryoprotectant and nanoparticles are gradually flushed out while gently raising the temperature further from −8 °C to +4 °C. The kidney was then tested a variety of ways to make sure it still could function, and then they also analyzed the tissue under a microscope. The figure below was created by ChatGPT with the free version, one-shot, and may have slight errors. link to preprint below