Enhanced cryopreservation performance of PVA grafted monolayer graphite oxide with synergistic antifreezing effect and rapid rewarming

In cryopreservation of biological samples such as cells, the formation, growth and recrystallization of ice crystals can cause fatal mechanical damage to cells. Therefore, how to effectively regulate and inhibit ice crystals, reduce freezing damage, and improve cryopreservation efficiency is a critical scientific problem that needs to be addressed in the current cryopreservation field. In this paper, a series of PVA grafted single-layer graphite oxide (PVA-g-GO nanocomposites) with different degrees of polymerization and different proportions was ingeniously engineered by a one-step esterification reaction method to study their ice crystal control effect. The obtained PVA17-g-GO nanocomposite could effectively reduce the ice crystal size during the recrystallization process at low concentration by adsorption and lattice matching. The nanocomposite with a 10:1 mass ratio of PVA and GO exhibited the best ice control effect, which could reduce the ice crystal size to only 17 % of that of pure water. Surprisingly, the modification of PVA significantly enhanced the absorption value of GO in Visible and Near-Infrared light (380 nm–980 nm), giving it excellent photothermal conversion efficiency (39.7 %), accelerating ice thawing rate, and thus synergistically reducing the mechanical damage caused by ice recrystallization. Finally, using the prepared PVA17-g-GO as cryoprotectants (CPA), the cryopreservation experiments on Hela cells and A549 cells demonstrated that this material at low concentration of 20 μg/ml could achieve high cell survival efficiency (>85 %). The preparation and development of this efficient ice-recrystallization-inhibiting nanomaterial with bidirectional synergy can provide new ideas and methods for the safety and progress of current cryopreservation technology.