Woods E J, Liu J, Gilmore J A, Reid T J, Gao D Y, Critser J K
General BioTechnology, LLC, Carmel, Indiana, USA.
Cryobiology. 1999 May;38(3):200-8. doi: 10.1006/cryo.1998.2146.
Attempts to cryopreserve human blood platelets have resulted in poor postthaw survival rates and have been inadequate for routine clinical application. As a result, most blood banks maintain platelets in nonfrozen solutions. Using this approach, platelets can be stored for only about 5 days and are then discarded. This situation greatly limits the use of platelet transfusion in clinical practice. Information regarding fundamental cryobiological characteristics can be applied to predict platelet response to cryoprotective agent (CPA) addition/removal and to cooling/warming. Methods can then be engineered to optimize cryopreservation procedures, thereby minimizing platelet damage and maximizing postthaw recovery. It was therefore the purpose of this study to determine some of the necessary biophysical parameters required for this process: (i) plasma membrane hydraulic conductivity (Lp), (ii) cryoprotectant solute permeability coefficient (Ps), (iii) the associated reflection coefficient (sigma), and (iv) their activation energies. The CPAs studied included dimethyl sulfoxide (Me2SO) and propylene glycol at 1.5 M concentration. Permeability was measured at 22, 10, and 4 degrees C using a modified Coulter counter in conjunction with a water-jacketed beaker system for temperature regulation. The Kedem-Katchalsky formalism was used to estimate the parameters using: (1) a three-parameter fit and (2) a two-parameter fit in which a noninteracting value of sigma was calculated. Two-parameter estimates were in closer agreement with previously published values, and these were used in a model to simulate addition and removal of 0.64 M (5%) and 1.0 M (7.8%) Me2SO, the most common CPA currently used in empirically determined platelet cryopreservation protocols.
尝试对人类血小板进行冷冻保存，结果显示解冻后存活率较低，且不足以用于常规临床应用。因此，大多数血库将血小板保存在非冷冻溶液中。采用这种方法，血小板只能保存约5天，然后就会被丢弃。这种情况极大地限制了血小板输血在临床实践中的应用。有关基本低温生物学特性的信息可用于预测血小板对添加/去除冷冻保护剂（CPA）以及冷却/升温的反应。然后可以设计方法来优化冷冻保存程序，从而将血小板损伤降至最低，并使解冻后回收率最大化。因此，本研究的目的是确定该过程所需的一些必要生物物理参数：（i）质膜水力传导率（Lp），（ii）冷冻保护剂溶质渗透系数（Ps），（iii）相关反射系数（sigma），以及（iv）它们的活化能。所研究的CPA包括浓度为1.5 M的二甲基亚砜（Me2SO）和丙二醇。使用改良的库尔特计数器结合带水套的烧杯系统进行温度调节，在22、10和4摄氏度下测量渗透率。使用Kedem-Katchalsky形式主义通过以下方式估计参数：（1）三参数拟合和（2）二参数拟合，其中计算sigma的非相互作用值。二参数估计与先前发表的值更接近，并且这些估计值被用于一个模型中，以模拟添加和去除0.64 M（5%）和1.0 M（7.8%）的Me2SO，这是目前经验性确定的血小板冷冻保存方案中最常用的CPA。
