title: Toward Optimal Cryopreservation and Storage for Achievement of High Cell Recovery and Maintenance of Cell Viability and T Cell Functionality.
abstract: Cryopreservation of biological materials such as cells, tissues, and organs is a prevailing topic of high importance. It is employed not only in many research fields but also in the clinical area. Cryopreservation is of great importance for reproductive medicine and clinical studies, as well as for the development of vaccines. Peripheral blood mononuclear cells (PBMCs) are commonly used in vaccine research where comparable and reliable results between different research institutions and laboratories are of high importance. Whereas freezing and thawing processes are well studied, controlled, and standardized, storage conditions are often disregarded. To close this gap, we investigated the influence of suboptimal storage conditions during low-temperature storage on PBMC viability, recovery, and T cell functionality. For this purpose, PBMCs were isolated and exposed with help of a robotic system in a low-temperature environment from 0 up to 350 temperature fluctuation cycles in steps of 50 cycles to simulate storage conditions in large biorepositories with sample storage, removal, and sorting functions. After the simulation, the viability, recovery, and T cell functionality were analyzed to determine the number of temperature rises, which ultimately lead to significant cell damage. All studied parameters decreased with increasing number of temperature cycles. Sometimes after as little as only 50 temperature cycles, a significant effect was observed. These results are very important for all fields in which cell cryopreservation is employed, particularly for clinical and multicenter studies wherein the comparability and reproducibility of results play a crucial role. To obtain reliable results and to maintain the quality of the cells, not only the freezing and thawing processes but also the storage conditions should be controlled and standardized, and any deviations should be documented.
authors: 1 Fraunhofer Institute for Biomedical Engineering , Sulzbach, Germany .
authors: Stephanie
authors: S
authors: Angel
authors: 1 Fraunhofer Institute for Biomedical Engineering , Sulzbach, Germany .
authors: Hagen
authors: H
authors: von Briesen
authors: 1 Fraunhofer Institute for Biomedical Engineering , Sulzbach, Germany .
authors: Young-Joo
authors: YJ
authors: Oh
authors: 2 University of Applied Sciences Kaiserslautern , Amerikastraße, Zweibruecken, Germany .
authors: Marko K
authors: MK
authors: Baller
authors: 1 Fraunhofer Institute for Biomedical Engineering , Sulzbach, Germany .|3 Department of Molecular and Cellular Biotechnology, Saarland University , Saarbruecken, Germany .
authors: Heiko
authors: H
authors: Zimmermann
authors: 1 Fraunhofer Institute for Biomedical Engineering , Sulzbach, Germany .
authors: Anja
authors: A
authors: Germann
mesh_terms: D001793:Blood Preservation; D049109:Cell Proliferation; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology*; D015203:Reproducibility of Results; D013048:Specimen Handling / Q000379:methods*; D013601:T-Lymphocytes / Q000166:cytology*
keywords: PBMC; T-cell functionality; cryopreservation; recovery; temperature fluctuations; viability