Intracellular trehalose improves the survival of cryopreserved mammalian cells.

We report that the introduction of low concentrations of intracellular trehalose can greatly improve the survival of mammalian cells during cryopreservation. Using a genetically engineered mutant of Staphylococcus aureus alpha-hemolysin to create pores in the cellular membrane, we were able to load trehalose into cells. Low concentrations (0.2 M) of trehalose permitted long-term post-thaw survival of more than 80% of 3T3 fibroblasts and 70% of human keratinocytes. These results indicate that simplified and widely applicable freezing protocols may be possible using sugars as intracellular cryoprotective additives.