The Microscopic Forces That Break Hearts
9 days ago
- #Thermomechanical Stress
- #Organ Transplantation
- #Cryopreservation
- Accidental freezing of lettuce demonstrates how ice crystals damage cell membranes, a problem magnified in complex organs like the human heart.
- Dr. Yoed Rabin's research focuses on thermomechanical stress in vitrified organs, combining materials science and biology to improve preservation techniques.
- Cryoprotectants like VS55 prevent ice formation, but molecules can still degrade tissue unless cooled below the glass transition temperature (-123°C for VS55).
- Preservation requires cooling to -150°C to ensure molecular motion stops completely, avoiding the dangerous middle ground where slow degradation occurs.
- Mechanical stress from uneven cooling rates can fracture organs, necessitating engineering solutions to manage thermal gradients and forces.
- Container design significantly impacts stress distribution during cooling and warming, with cylindrical containers causing up to 94% higher stress than flexible bags.
- Scaling up preservation techniques from rat to human hearts introduces non-linear challenges due to differing thermal gradients and stress profiles.
- Nanoparticle-assisted warming (using silica-coated iron oxide nanoparticles) offers a solution but requires precise distribution to avoid uneven heating and stress.
- The research highlights the humanitarian impact of improving organ preservation, potentially eliminating transplant waitlists by utilizing currently discarded organs.