Methods to stabilize aqueous supercooling identified by use of an isochoric nucleation detection (INDe) device

TL;DR

This study introduces an isochoric nucleation detection platform to systematically analyze and enhance the stability of aqueous supercooling, with implications for biopreservation and food storage.

Contribution

The paper presents a novel high-throughput INDe device and demonstrates how simple modifications can significantly improve supercooling stability.

Findings

Isochoric confinement increases supercooling stability.

Hydrophobic container walls enhance supercooling.

Addition of solutes extends supercooling durations.

Abstract

Stable aqueous supercooling has shown significant potential as a technique for human tissue preservation, food cold storage, conservation biology, and beyond, but its stochastic nature has made its translation outside the laboratory difficult. In this work, we present an isochoric nucleation detection (INDe) platform for automated, high-throughput characterization of aqueous supercooling at >1 mL volumes, which enables statistically-powerful determination of the temperatures and time periods for which supercooling in a given aqueous system will remain stable. We employ the INDe to investigate the effects of thermodynamic, surface, and chemical parameters on aqueous supercooling, and demonstrate that various simple system modifications can significantly enhance supercooling stability, including isochoric (constant-volume) confinement, hydrophobic container walls, and the addition of even mild concentrations of solute. Finally, in order to enable informed design of stable supercooled biopreservation protocols, we apply a statistical model to estimate stable supercooling durations as a function of temperature and solution chemistry, producing first-in-field supercooling stability maps for four common cryoprotective solutes.