C-1000: Effect of hydroxyapatite nanoparticles on subzero water transport of HeLa cells

Abstract

Nano-cryopreservation is a newly emerged field which is promising to deal with the major challenges in typical cryopreservation methods. Although addition of nanoparticles is found to significantly affect the behavior of devitrification, recrystallization, and thermal transfer properties of cryopreservation solutions, investigation of its effect on freezing response of living cells is scarce in literature. However, there leaves many intriguing questions. For example, as pointed in literature, adding nanoparticles to cell suspension can enhance extracellular ice formation. With decreasing of the temperature, the increased water chemical potential difference across the cell membrane may induce more water flux out of the cells. Nevertheless, adding of nanoparticles may also increase the viscosity of the extracellular solution, which can impede such water transport process. In this study, subzero water transport of HeLa cells with different concentration of hydroxyapatite (HA) nanoparticles under incubation and no-incubation was quantitatively investigated. Hydroxyapatite (HA) was utilized as the nanoparticles material considering its good biocompatibility with cell membrane since unsuitable nanoparticles can be toxic to cells and bring additional cell injury. By obtaining the water permeability parameters, we found the subzero water transport was facilitated by addition of HA nanoparticles. And such influence turned out to be enhanced after incubation. What’s more, the higher the concentration of HA, the higher the water permeability. Possible influence mechanisms will be further discussed.