Mukherjee Indra Neil, Song Ying C, Sambanis Athanassios
School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Cryobiology. 2007 Aug;55(1):10-8. doi: 10.1016/j.cryobiol.2007.04.002. Epub 2007 Apr 10.
Development of optimal cryopreservation protocols requires delivery and removal of cryoprotective agents (CPAs) in such a way that negative osmotic and cytotoxic effects on cells are minimized. This is especially true for vitrification, where high CPA concentrations are employed. In this study, we report on the determination of cell membrane permeability parameters for water (L(p)) and solute (P(s)), and on the design and experimental verification of CPA addition and removal protocols at vitrification-relevant concentrations for a murine insulinoma cell line, betaTC-tet cells. Using membrane permeability values and osmotic tolerance limits, mathematical modeling and computer simulations were used to design CPA addition and removal protocols at high concentrations. The cytotoxic effects of CPAs were also evaluated. Cells were able to tolerate the addition and removal of 2.5M dimethyl sulfoxide (DMSO) and 2.5M 1,2 propanediol (PD) in single steps, but required multi-step addition and removal with 3.0M DMSO, 3.0M PD, and a vitrification-relevant concentration of 3.0M DMSO+3.0M PD. Cytotoxicity studies revealed that betaTC-tet cells were able to tolerate the presence of single component 6.0M DMSO and 6.0M PD and to a lesser extent 3.0M DMSO+3.0M PD. These results determine the time and concentration domain of CPA exposure that cells can tolerate and are essential for designing cryopreservation protocols for free cells as well as cells in engineered tissues.
制定最佳冷冻保存方案需要以将对细胞的负渗透和细胞毒性作用降至最低的方式输送和去除冷冻保护剂(CPA)。对于采用高浓度CPA的玻璃化冷冻而言尤其如此。在本研究中,我们报告了对小鼠胰岛素瘤细胞系βTC-tet细胞的水(L(p))和溶质(P(s))的细胞膜通透性参数的测定,以及与玻璃化相关浓度下CPA添加和去除方案的设计与实验验证。利用膜通透性值和渗透耐受极限,通过数学建模和计算机模拟来设计高浓度下的CPA添加和去除方案。还评估了CPA的细胞毒性作用。细胞能够单步耐受添加和去除2.5M二甲基亚砜(DMSO)和2.5M 1,2-丙二醇(PD),但对于3.0M DMSO、3.0M PD以及与玻璃化相关浓度的3.0M DMSO + 3.0M PD则需要多步添加和去除。细胞毒性研究表明,βTC-tet细胞能够耐受单一组分6.0M DMSO和6.0M PD的存在,对3.0M DMSO + 3.0M PD的耐受程度稍低。这些结果确定了细胞能够耐受的CPA暴露的时间和浓度范围,对于设计游离细胞以及工程组织中细胞的冷冻保存方案至关重要。