液液凝聚相抑制抗冻（糖）蛋白溶液中冰晶爆长机制的研究及其在细胞冷冻保存中的应用

细胞、组织等生物样本的冷冻保存是面向人民生命健康的科技前沿，而抑制冰晶的不可控生长是冻存成功的关键。二甲亚砜等传统有机溶剂型冻存剂控冰效率低、有细胞毒性并且损伤组织结构，无法满足生物样本安全有效冻存的需求。自然界耐寒生物体内的抗冻（糖）蛋白（AF(G)Ps）是保护其不受冰冻损害的关键分子，其优越的抑冰活性是合成材料无法比拟的。然而AF(G)Ps离开其原生环境后，抑冰作用只在一定的温度区间有效，继续降温则冰晶爆发性生长，破坏组织结构。因此，有效抑制冰晶爆长是AF(G)Ps在冻存中应用的关键。我们前期探索实验发现聚合物和有机盐形成的液液凝聚相能够有效地抑制这种冰晶爆长。本项目中，我们将系统研究利用液液凝聚相提供的环境发挥AF(G)Ps的高效控冰效果的作用机制，探讨液液凝聚相与AF(G)Ps混合体系应用于间充质干细胞的冻存效果，摒弃传统有机溶剂型冻存剂的使用，发展生物样本冷冻保存的新思路。

The cryopreservation of biological samples such as cells and tissues is the cutting-edge science and technology to benefit people's lives and health. Inhibiting the uncontrollable growth of ice crystals is the key to the success of cryopreservation. Traditional cryoprotectants (CPA), such as dimethyl sulfoxide (DMSO), are inefficient in ice inhibiting, toxic to cells and damaging to structure of tissues, thereby unable to meet the demands of safe and efficient cryoprotection of cells and tissues. Antifreeze (glyco)proteins (AF(G)Ps) in cold-tolerant organisms can effectively inhibit the formation or growth of ice crystals to avoid the possible ice crystal damage in subzero environments. Their ice inhibiting efficiency is incomparable by any synthesized materials. However, it has been found that in vitro AF(G)Ps' ice suppression effect is only effective in a certain temperature range, and continuous cooling of ice crystals will cause extremely destructive and explosive growth, leading to the failure of cryopreservation. Effectively inhibiting the explosive ice growth is crucial for the successful application of AF(G)Ps in cryopreservation and will bring revolutionary progress in the field of cryopreservation. Our previous research found that the condensates of liquid-liquid phase separation (C-LLPS) formed by polymers and organic salts can effectively inhibit the explosive ice growth in the AF(G)Ps solution. In the present, we will systematically study the mechanism of C-LLPS inhibiting the explosive ice growth in AF(G)P solution, reveal its generality in inhibiting ice explosive growth in solutions of different kinds of AF(G)Ps, and apply the C-LLPS/AF(G)Ps mixtures in the cryopreservation of stem cells. This project will cast light on a new perspective in the cryopreservation of cells, tissues, and organs.