Figure 5.

Nanoparticle‐mediated cryopreservation of NK cells. A) Diagram showing cryopreservation workflow followed in this work. B) Number of recovered NK cells in culture following cryopreservation. NK cells were pretreated with free trehalose alone, empty nanoparticles, trehalose‐loaded nanoparticles, or DMSO control. After cryopreservation and thawing in the absence of DMSO, NK cells were placed in culture media at 37 °C, and cell number was monitored over 21 days. C) Viability of NK cells in culture after cryopreservation. After thawing, cells from all treatment groups were placed in culture media at 37 °C and 5% CO₂, and the viability measured by trypan blue staining, either immediately upon thawing (day 0), or after 7, 14, or 21 days; *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.