Synthetic zwitterions as efficient non-permeable cryoprotectants

Area of Science:

• Cell biology
• Biochemistry
• Materials science

Background:

• Effective cell cryopreservation is crucial for long-term storage but challenging for certain cell lines.
• Existing commercial cryoprotectants and previously developed zwitterion solutions show limitations in preserving some cell types, like human kidney BOSC cells.
• Understanding the mechanisms of zwitterion cryoprotective effects is needed for optimization.

Purpose of the Study:

• To investigate the cryoprotective mechanisms of synthetic zwitterions.
• To optimize zwitterion-based cryopreservation solutions for improved cell viability.
• To explore the synergistic effects of zwitterions with cell-permeable cryoprotectants.

Main Methods:

• Synthesis and evaluation of 18 zwitterion species and their water mixtures.
• Assessment of physical properties and cryoprotective effects on various cell lines (BOSC, K562, OVMANA).
• Combination of non-cell-permeable zwitterions with dimethyl sulfoxide (DMSO) and molecular dynamics simulations.

Main Results:

• Non-cell-permeable zwitterions inhibit ice formation and dehydrate cells, but some cells require enhanced dehydration.
• A optimized mixture of water/zwitterion/DMSO (90/10/15, v/w/w) significantly improved cryopreservation of freezing-vulnerable cells (K562, OVMANA).
• Cell viability was approximately 1.8-fold higher compared to commercial cryoprotectants; molecular dynamics confirmed zwitterions protect cell membranes from DMSO-induced damage.

Conclusions:

• Zwitterions offer cryoprotection by inhibiting ice formation and inducing dehydration.
• Combining zwitterions with DMSO creates a highly effective cryopreservation solution for previously difficult-to-preserve cells.
• This novel approach enhances cell membrane stability during cryopreservation, surpassing current commercial methods.