Stem cells have been widely touted to be the next medical marvel, able to cure a whole host of diseases and conditions previously incurable using traditional medicine or therapies. It has been almost 30 years, since the first discovery of mouse embryonic stem cells in 1981, and to date, there are no less than 200 companies around the world involved in the development of stem cell therapies. The projected revenues from stem cell therapies in 2016 are estimated to be around $8.5 billion. Current stem cell research is focused around the use of embryonic, mesenchymal and haematopoietic stem cells (HSCs), of which, haematopoietic stem cells are the most commonly used stem cell in therapy today.

Whilst the derivation of the embryonic or pluripotent stem cell was discovered in the 80s, in fact, the use of haematopoietic stem cells, or blood forming stem cells, have been going on for over 50 years, since 1959, when the first bone marrow transplant was performed on radiation-induced marrow failure patients. This medical breakthrough followed a number of years later by the discovery of similar haematopoietic stem cells in human umbilical cord blood, that lead the first umbilical cord blood transplant in 1988 for Fanconi's anemia.

Since the first umbilical cord blood (UCB) transplant was performed in 1988, the use of UCB for the treatment of malignant (and non-malignant) haematological disorders has been increasingly well-accepted. By year 2008, which is the 20th anniversary of the first UCB transplantation, more than 10,000 cord blood transplant procedures have been performed. A deepening knowledge of umbilical cord blood haematology, as well with growing clinical experience, the number of diseases that can be treated with UCB has grown exponentially over the years to over 80, with potential non-haematological applications, such as cerebral palsy and myocardial regeneration, undergoing extensive studies.

Early experimental evidence was established in the late 1970s – early 1980s on the presence of HSCs in cord blood. The discovery of multipotent hematopoietic progenitor/stem cells in human umbilical cord blood (UCB) was first reported by Nakahata et al (1982), where a distinct population of progenitor cells that was able to differentiate into granulocyte-erythrocyte-macrophage-megakaryocytic lineages, and also self renewal in secondary culture. Subsequently, Broxmeyer et al (1989) showed experimental evidence that UCB was a rich source of HSCs. These studies coupled with optimal cryopreservation methods culminated in the first UCB HSC transplantation in 1988 when Gluckman et al reported the first clinical use of UCB for HSC transplantation, as an alternative to bone marrow.

In the 1990s, improved methods for the isolation of nucleated cells from UCB lead the earliest initiatives to establish large national umbilical cord blood banks using public funding.

In 1995, Rubinstein et al reported a high recovery method for the cord blood volume reduction using hetastarch mediated density gradient separation to achieve the nucleated cell component isolation. This has gone on to be the foundation on which both private and public cord blood banking has been built. In the last decade, further technological advances have allowed for the development of automated cord blood processing methods, which have vastly improved nucleated cell yields, productivity, and consistency. To date, up to 70% of European Netcord banks have adopted automated cord blood processing using the Swiss-made Sepax automated processing system.

With increasing number of cord blood transplants being performed, clinical observation (1989-1992) that Graft vs Host Disease (GvHD) was reduced even in HLA-incompatible cord blood transplantation. This has been found to be due to the relative immaturity of the immune system at birth, resulting in the CB cells producing less inflammatory factors that trigger GvHD. Cord blood transplantation also appears to allow a Graft-versus-Leukaemiaa effect without GvHD, which helps to eradicate leukaemia, especially in chronic myeloid leukaemia (2000-2004).

Several studies have suggested that in addition to the obvious therapeutic potential of cord blood hematopoietic stem cells, populations of mesenchymal cells (also known as stromal cells) found in umbilical cord blood could be beneficial to cardiac repair, neurological regeneration and other such regenerative applications.

Extensive work being carried out around the world on the development of new stem cell technologies to both expand this variety of stem cell types and to apply them in an ever widening array  of diseases, neurological diseases such as Alzheimer's and Parkinson's disease, tissue engineering and replacement, such as Type I Diabetes and Osteoarthritis. There still remain a number of technological, biological and regulatory challenges that need to be met, before the medical and biotechnology community will begin to see the true economic and therapeutic potential of stem cells. The registration and approval of a landmark clinical trial for the use of embryonic stem cells in the treatment of spinal cord injury patients by Geron in 2010 is a breakthrough that will most likely be followed by number of stem cell therapies move from the research to clinical investigation.

In conclusion, umbilical cord blood has been found to be a very rich source of adult stem cells. Over the last 20 years, the number of cord blood transplants has increased year on year, and the biological understanding of cord blood stem cells has grown tremendously. This has lead to more than 80 clinical applications to date. Stem cell technology and therapy have seen tremendous interest and growth in the last few years and holds the promise for many more healthcare applications in future.     

Dr. Steven Fang is  Group CEO &  Dr. Andrew Wu - Group is  Technical Director ,CordLife Ltd.