Kidney preservation at subzero temperatures using a novel storage solution and insect ice-binding proteins.

Area of Science:

• Organ preservation
• Transplantation biology
• Cryobiology

Background:

• Current kidney preservation relies on hypothermia (4°C) for up to 24 hours.
• Extending safe kidney storage time is crucial for increasing organ availability.

Purpose of the Study:

• To evaluate the efficacy of a proprietary CryoStasis (CrS) solution for subzero kidney preservation.
• To assess the impact of adding insect antifreeze protein (TmAFP) to CrS on kidney viability and ischemic damage markers.

Main Methods:

• Rat kidneys were preserved using University of Wisconsin (UW) solution (4°C, 24h) as a control.
• Kidneys were stored in CrS (-2°C, 48h) and CrS with TmAFP (-4.4°C, 72h).
• Viability was assessed via MTT assays and FDA/PI staining; ischemic damage markers (caspase-3, calpain activity) were analyzed.

Main Results:

• Kidneys preserved in CrS for 48 hours showed comparable enzymatic activity to 24-hour UW preserved kidneys.
• Kidneys preserved in CrS with TmAFP for 72 hours also demonstrated similar enzymatic activity levels to controls.
• Subzero preservation with CrS and TmAFP maintained kidney viability and reduced markers of ischemic damage.

Conclusions:

• Subzero preservation using CryoStasis solution, particularly with TmAFP, significantly prolongs the safe storage time for kidneys.
• This advanced preservation method holds promise for increasing the availability of donor organs for renal transplantation.