Ice Inhibition for Cryopreservation: Materials, Strategies, and Challenges

Cryopreservation technology has developed into a fundamental and important supporting method for biomedical applications such as cell-based therapeutics, tissue engineering, assisted reproduction, and vaccine storage. The formation, growth, and recrystallization of ice crystals are the major limitations in cell/tissue/organ cryopreservation, and cause fatal cryoinjury to cryopreserved biological samples. Flourishing anti-icing materials and strategies can effectively regulate and suppress ice crystals, thus reducing ice damage and promoting cryopreservation efficiency. This review first describes the basic ice cryodamage mechanisms in the cryopreservation process. The recent development of chemical ice-inhibition molecules, including cryoprotectant, antifreeze protein, synthetic polymer, nanomaterial, and hydrogel, and their applications in cryopreservation are summarized. The advanced engineering strategies, including trehalose delivery, cell encapsulation, and bioinspired structure design for ice inhibition, are further discussed. Furthermore, external physical field technologies used for inhibiting ice crystals in both the cooling and thawing processes are systematically reviewed. Finally, the current challenges and future perspectives in the field of ice inhibition for high-efficiency cryopreservation are proposed.