Profiling the Morphology Effects of MoS₂ Nanomaterials on Ice Suppression and Rapid Rewarming for Cryopreservation

With the booming development of nanotechnology, an increasing number of nanomaterials and engineering strategies are being used to explore the effective inhibition of ice crystals, thereby reducing ice damage to biological samples and improving the efficiency of cryopreservation. However, the ice-inhibiting effect of nanomaterial shapes and their corresponding photothermal behavior have rarely been studied in depth in cell cryopreservation applications. Here, molybdenum disulfide (MoS 2 ) nanomaterials with different morphologies [nanosheets (NSs), nanoflowers (FLs), and nanomicrospheres (MSs)] were controllably synthesized by a hydrothermal method to profile the influence of MoS 2 morphology on ice suppression and rapid rewarming. The prepared MoS 2 nanomaterials exhibited excellent capabilities for regulating the nucleation temperature and recrystallization size of ice crystals, which varied with morphology (MSs > FLs > NSs). Unique surface morphology, more functional groups on the surface that could form hydrogen bonds with ice/water molecules, and the adsorption-inhibition mechanism contributed to the excellent ice regulation performance. Surprisingly, the photothermal effect of MoS 2 MSs was also the best as the temperature could sharply rise from 24 to 82 °C under 808 nm laser irradiation for 1 min. Finally, using MoS 2 MSs as a cryoprotectant (CPA) to cryopreserve A549 cells, a cell survival rate of 85.3% was still achieved even when MoS 2 MSs replaced 90% of dimethyl sulfoxide in the CPA solution. Our work is the first to correlate the shape variations of nanomaterials with their regulation of ice crystal behavior during the freezing-thawing process and photothermal properties, synergistically improving the efficiency of cell cryopreservation. This study provides guidance for the practical design of nanomaterials for collaborative deicing.