As is sensed in our daily life, jiaozi frozen in domestic refrigerator tastes less delicious than an instant frozen one sold in the supermarket. The formation of the ice crystal is to blame. In scientific researches ranging from aerospace to biology and medicine, the formation, growth and elimination of the ice crystal are of significant importance.
By far, slow freezing and vitrification are generally adopted for cryopreservation. The former method, assembling freezing jiaozi with domestic refrigerator, is accompanied by mass formation of ice crystal which inevitably does irreversible damage to the cell. Vitrification effectively avoids former problems but requires either extremely rapid freezing rate which is too hard to achieve or high density of agent which is equally harmful to the sample. Even if all the damages have been avoided during freezing, recrystallization will do fatal damage while thawing. To successfully preserve the samples, the only possible solution is to avoid crystallization through the entire process.
Recently, Prof. ZHAO Gang's team from University of Science and Technology of China of Chinese Academy of Sciences (CAS) presented prospective insights on cryopreservation. The work was published in Advanced Science on February 1st. The thesis unprecedentedly integrated mechanism, chemical ice-inhibition molecules and other disciplines to cope with crystallization of cryopreservation. The inspiration in the thesis is likely to shed instructive light on technical innovation of cryobiology. Based on previous researches, Prof. ZHAO's team joined hands with Prof. SONG Li's team from National Synchrotron Radiation Laboratory and Prof. WANG Hai's team from National Center for Nanoscience and Technology and put forward new method of restraining crystallization of cryopreservation. Another thesis titled Synergistic Ice Inhibition Effect Enhances Rapid Freezing Cryopreservation with Low Concentration of Cryoprotectants was published in Advanced Science on January 29th.
In their researches, nanocomposites were constructed to control the growth and elimination together with function materials and external physical field. This nanometer material is of high quality when it comes to restraining crystallization: it's capable of regulating ice nucleation thus reduce the damage done to the sample; by selectively absorbing onto the crystal and melting the crystal, this nanocomposite helps the sample survive the injuries caused during thawing; because of the protection from the nanocomposite, the cells not only survive the cryopreservation but proliferate as well. The technical breakthrough on suppressing the formation and the growth of the ice crystals for the cryopreservation of cells and organs provide some fundamental support for future medical research and clinical treatment.