Cellular responses to severe dehydration during spin-drying resemble hyperosmotic stress

Dry preservation could potentially eliminate the need for low-temperature storage and cytotoxic cryoprotective agents. However, mammalian cells are sensitive to desiccation, and the cellular processes associated with drying-induced injury remain poorly understood. Drying and hyperosmotic stress both cause cellular dehydration, and previous studies have revealed similarities in these stresses. Here, we characterized drying injury by spin-drying HepG2 cells. We found that drying induced cellular responses closely resembled those caused by hyperosmotic dehydration, including cell shrinkage, membrane blebbing, cytoskeleton disruption, and widespread protein aggregation. In addition, trehalose suppressed extracellular salt crystallization during drying. Notably, cell death occurred within a narrow time window, suggesting that direct exposure to the gas phase and consequent rapid intracellular water loss may cause lethal injury. This work may guide future studies toward improved dry preservation strategies.