Hibernating/Awakening Nanomotors Promote Highly Efficient Cryopreservation by Limiting Ice Crystals.

The disruptions caused by ice crystal formation during the cryopreservation of cells and tissues can cause cell and tissue damage. Thus, preventing such damage during cryopreservation is an important but challenging goal. Here, a hibernating/awakening nanomotor with magnesium/palladium covering one side of a silica platform (Mg@Pd@SiO 2 ) is proposed. This nanomotor is used in the cultivation of live NCM460 cells to demonstrate a new method to actively limit ice crystal formation and enable highly efficient cryopreservation. Cooling Mg@Pd@SiO 2 in solution releases Mg 2+ /H 2 and promotes the adsorption of H 2 at multiple Pd binding sites on the cell surface to inhibit ice crystal formation and cell/tissue damage; additionally, the Pd adsorbs and stores H 2 to form a hibernating nanomotor. During laser-mediated heating, the hibernating nanomotor is activated (awakened) and releases H 2 , which further suppresses recrystallization and decreases cell/tissue damage. These hibernating/awakening nanomotors have great potential for promoting highly efficient cryopreservation by inhibiting ice crystal formation.