Freezing Stability of Soft Particles – FROST

Cryopreservation, the preservation of living cells by freezing them, is the single available strategy to extend the lifespan of living cells and tissues, a central requisite to activities spanning from fundamental biology to clinical practice, including cell therapy, stem cell research or blood storage. The design of efficient and non toxic cryopreservation processes and formulations is hampered by the fact that fundamental aspects of cryopreservation remain elusive due to the lack of appropriate tools to describe it. The freezing of living cells is a complex interplay of physical, chemical, and biological phenomena which need to be decoupled. We thus need simplified, model particles, reproducing some of the cell's features, on which we can investigate the fundamental physical, chemical, and physico-chemical mechanisms at play during the freezing of cells.
The goal of the FROST project is to gain fundamental knowledge on the physico-chemical mechanisms at play during the freezing of model soft particles (double emulsions, phospholipid vesicles) to rationalize the design of cells cryopreservation protocols. We will investigate in situ using cryo-confocal microscopy the freezing dynamics of a range of model soft particles with controlled deformability and permeability and increasing step-by-step the complexity of the particles and effects, from water-in oil-in water double emulsions & vesicles to ghost cells and finally red blood cells.
The physical insights gained in FROST will be a major step towards a comprehensive understanding of the freezing stability of these soft matter systems, and may be applied to cells relevant in biological studies and clinical research and practice, and help designing new cryoprotective formulations. The results should be useful for other applications where emulsions, liposomes or cells are frozen such as in food engineering, probiotic-loaded capsules, and vaccines and drug delivery systems.