Ice recrystallization inhibition activity in bile salts

Area of Science:

• Biochemistry
• Materials Science
• Cryobiology

Background:

• Ice recrystallization inhibitors (IRIs) are crucial for reducing freezing damage in cryopreservation.
• Known IRIs include antifreeze proteins, polymers, nanomaterials, and small molecules.
• Novel sources of potent IRIs are needed for improved cryoprotection.

Purpose of the Study:

• To investigate the ice recrystallization inhibition (IRI) activity of bile salts.
• To determine the relationship between bile salt structure and IRI potency.
• To explore the potential of bile salts as novel cryoprotective agents.

Main Methods:

• Tested various bile salts for IRI activity in phosphate-buffered saline (PBS).
• Assessed IRI activity by observing ice growth under controlled conditions.
• Investigated the effect of bile salt concentration and structure on IRI potency.

Main Results:

• Bile salts exhibit significant ice recrystallization inhibition (IRI) activity.
• IRI potency increases with decreasing hydroxyl groups (hydrophobicity) in bile salts.
• Sodium lithocholate (NaLC) at 25.0 mM completely inhibited ice growth under tested conditions.
• IRI activity was observed above the critical micelle concentration and was independent of viscosity, gelation, or liquid crystal formation.
• Some bile salts increased ice nucleation temperature but did not exhibit ice shaping or thermal hysteresis.

Conclusions:

• Bile salts are identified as a new class of potent ice recrystallization inhibitors.
• The findings expand the repertoire of materials for cryoprotection.
• Bile salts offer a promising avenue for developing novel cryoprotective agents.