Review
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Stem Cells. Sep 26, 2021; 13(9): 1197-1214
Published online Sep 26, 2021. doi: 10.4252/wjsc.v13.i9.1197
Effects of storage media, supplements and cryopreservation methods on quality of stem cells
Ozgur Dogus Erol, Burcu Pervin, Mehmet Emin Seker, Fatima Aerts-Kaya
Ozgur Dogus Erol, Burcu Pervin, Mehmet Emin Seker, Fatima Aerts-Kaya, Department of Stem Cell Sciences, Hacettepe University Graduate School of Health Sciences, Ankara 06100, Turkey
Ozgur Dogus Erol, Burcu Pervin, Mehmet Emin Seker, Fatima Aerts-Kaya, Center for Stem Cell Research and Development, Hacettepe University, Ankara 06100, Turkey
Author contributions: Erol OD, Pervin B and Seker ME drafted the first version of the article and contributed equally to this work; Aerts-Kaya F designed the manuscript, reviewed the contents and wrote the final version of the article to be published; All authors have read and approved the final manuscript.
Supported by the Scientific and Technological Research Council of Turkey (TÜBİTAK), No. 118S738 and No. 219S675.
Conflict-of-interest statement: The authors declare no conflicts of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Fatima Aerts-Kaya, MD, PhD, Associate Professor, Department of Stem Cell Sciences, Hacettepe University Graduate School of Health Sciences, Ankara 06100, Turkey. fatimaaerts@yahoo.com
Received: February 27, 2021
Peer-review started: February 27, 2021
First decision: April 20, 2021
Revised: April 21, 2021
Accepted: August 24, 2021
Article in press: August 24, 2021
Published online: September 26, 2021
Abstract

Despite a vast amount of different methods, protocols and cryoprotective agents (CPA), stem cells are often frozen using standard protocols that have been optimized for use with cell lines, rather than with stem cells. Relatively few comparative studies have been performed to assess the effects of cryopreservation methods on these stem cells. Dimethyl sulfoxide (DMSO) has been a key agent for the development of cryobiology and has been used universally for cryopreservation. However, the use of DMSO has been associated with in vitro and in vivo toxicity and has been shown to affect many cellular processes due to changes in DNA methylation and dysregulation of gene expression. Despite studies showing that DMSO may affect cell characteristics, DMSO remains the CPA of choice, both in a research setting and in the clinics. However, numerous alternatives to DMSO have been shown to hold promise for use as a CPA and include albumin, trehalose, sucrose, ethylene glycol, polyethylene glycol and many more. Here, we will discuss the use, advantages and disadvantages of these CPAs for cryopreservation of different types of stem cells, including hematopoietic stem cells, mesenchymal stromal/stem cells and induced pluripotent stem cells.

Keywords: Cryoprotective agents, Dimethyl sulfoxide, Hematopoietic stem cells, Mesenchymal stromal/stem cells, Induced pluripotent stem cells

Core Tip: The manuscript is an overview of current cryopreservation protocols used for cold storage of hematopoietic stem cells, mesenchymal stem cells and induced pluripotent stem cells. Although dimethyl sulfoxide (DMSO) is commonly used in cryopreservation of cell lines, primary cells and stem cells, the use of DMSO has been associated with certain toxicity, both directly on the cells, as well as upon infusion with the stem cell product. As a result of this many groups have undertaken efforts to find suitable replacements for DMSO that are equally potent but less toxic. In this review, we summarize the current status quo of stem cell freezing protocols and we describe the most commonly used cryoprotective agents and their effects on stem cells and stem cell function.