Effects of storage media,supplements and cryopreservation methods on quality of stem cells

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