The Banking and Cryopreservation of Human Embryonic Stem Cells

Human embryonic stem cells are pluripotent cells derived from the inner cell mass of the blastocyst. Once isolated in culture, they can produce stable cell lines with the capacity to provide differentiated cells from all three germ layers. This ability is the centre of an emerging field of research into applications ranging from tissue engineering and drug discovery to developmental biology and treatments for serious conditions such as Parkinson’s, diabetes and heart disease. An essential prerequisite for these developments is the production of banks of well-characterised and safety-tested cells for research and as seed stocks for therapeutic applications. This requires the cryopreservation of stem cells for long-term storage. Currently, conventional freezing and vitrification when applied to these cells has met with varying degrees of success. This has led to an emerging debate on the suitability of either method for cryopreservation of these cells. Such studies as have been undertaken have been empirical in nature, and to date, no methodological studies, such as those carried out on haematopoietic stem cells, have been published. This paper reviews the current debate on cryopreservation and places it in the context of stem cell banking for both research and therapy.