最小体积玻璃化冻存技术在生物医学领域的进展和应用

Progress and applications of minimum volume vitrification in biomedicine

细胞和组织的生物保存在辅助生殖医学、再生医学和器官移植等领域均具有至关重要的作用,对公共健康具有广泛影响.生物保存方法主要包括传统的程序化慢冻法(slow freezing)和玻璃化冻存技术(vitrification).玻璃化冻存技术可通过降低或避免结晶的产生而显著提高细胞解冻后的活性和功能.但玻璃化冻存技术通常采用较高浓度的冷冻保护剂(cryoprotectant agent, CPA),会对细胞和组织产生一定的毒性和渗透压力.研究显示,通过减小玻璃化冻存中样品的体积(<1μL)可显著提高冷却速率,从而降低玻璃化冻存所需的CPA浓度.而微纳技术的迅速发展使得皮升至纳升量级样本的操作成为可能.因此,微纳技术与低温学的有机结合将为未来生物保存技术的发展提供巨大的潜能.

Cell and tissue cryopreservation has played important roles in multiple fields such as assisted reproductive medicine, regenerative medicine and organ transplantation, and has created broader impacts on public health. Slow freezing and vitrification are the two main methods for biopreservation. Vitrification has demonstrated significant improvement in cell viability and function post thawing by reducing or even avoiding crystallization during freezing process. However, high concentrations of cryoprotectants often required for vitrification may induce toxicity and osmotic stress to cells and tissues. It has been indicated that vitrification using reduced sample volumes(i.e., <1 μl) can significantly elevate the cooling rate, thus reducing the CPA concentrations needed. The rapid development of nano-and micro-scale technologies in recent years has made it possible to manipulate samples in picoliter to nanoliter. Therefore,the integration of nanotechnologies with cryogenics would create great potential for the progress in biopreservation technology.