Algorithm-driven optimization of cryopreservation protocols for transfusion model cell types including Jurkat cells and mesenchymal stem cells

Abstract

This investigation describes the use of a differential evolution (DE) algorithm to optimize cryopreservation solution compositions and cooling rates for specific cell types. Jurkat cells (a lymphocyte model cell type) and mesenchymal stem cells (MSCs) were combined with non-DMSO solutions at concentrations dictated by a DE algorithm. The cells were then frozen in 96-well plates at DE algorithm-dictated cooling rates in the range 0.5–10°C/min. The DE algorithm was iterated until convergence resulted in identification of an optimum solution composition and cooling rate, which occurred within six to nine generations (seven to 10 experiments) for both cell types. The optimal composition for cryopreserving Jurkat cells included 300 mM trehalose, 10% glycerol and 0.01% ectoine (TGE) at 10°C/min. The optimal composition for cryopreserving MSCs included 300 mM ethylene glycol, 1 mM taurine and 1% ectoine (SEGA) at 1°C/min. High-throughput concentration studies verified the optimum identified by the DE algorithm. Vial freezing experiments showed that experimental solutions of TGE at 10°C/min resulted in significantly higher viability for Jurkat cells than DMSO at 1°C/min, while experimental solutions of SEGA at 10°C/min resulted in significantly higher recovery for MSCs than DMSO at 1°C/min; these results were solution- and cell type-specific. Implementation of the DE algorithm permits optimization of multicomponent freezing solutions in a rational, accelerated fashion. This technique can be applied to optimize freezing conditions, which vary by cell type, with significantly fewer experiments than traditional methods.

Combinations of Osmolytes, Including Monosaccharides, Disaccharides, and Sugar Alcohols Act in Concert During Cryopreservation to Improve Mesenchymal Stromal Cell Survival

“…Multicomponent solutions have also been explored and factorial experiments to identify favorable combinations and freezing protocols have shown increased success. 5,6 Previously published work by this group 7 describes algorithm optimization of multicomponent cryopreservative solutions, including molecules that target different aspects of cell protection during freezing.…”

“…20 However, the concentrations of these cryoprotectants dictate whether they will be stabilizing or destabilizing 21,22 and concentrations that result in stabilization optimums may differ when cryoprotectants are combined. 23 In a previous study, we established our ability to optimize the composition of a multicomponent osmolyte solution 7 using a computational algorithm. The focus of this investigation involves expanding our understanding of multicomponent osmolyte solutions and their ability to preserve cell viability during freezing.…”

Preservation and Stability of Cell Therapy Products: Recommendations from an Expert Workshop

“…The group agreed that further discussion on the application of such deep systems analysis for cell preparations for cell therapy could assist in the assessment of preservation methods. Furthermore, in-depth studies of different combinations of different culture media and matrices using highthroughput approaches are likely to identify improved preservation and stability of models systems as had been developed for gametes [12,13] (see Box 2 for Recommendation 2).…”

Advanced Biotechnology for Cell Cryopreservation

“…In order to improve cell cryopreservation efficiency, previous studies have mainly focused on the optimization of CPA formulation, CPA introduction, and freezing-thawing protocol suitable for different cell types [10,11]. Pollock et al [12] reported the use of a differential evolution algorithm to optimize cryopreservation protocols for Jurkat cells (300 mmol/L trehalose, 10% glycerol, and 0.01% ectoine at 10 °C/min) and mesenchymal stem cells (300 mmol/L ethylene glycol, 1 mmol/L taurine, and 1% ectoine at 1 °C/min), which resulted in post-thawing cell viabilities of 95% and 96%, respectively. However, the optimization of cryopreservation protocol still suffers from two major challenges: (1) unfavorable post-thaw cell viability or functions and (2) safety concerns induced by CPA toxicity.…”