In a world first, an international research team led by a Japanese scientist has developed an effective, inexpensive method for the stable, long-term expansion of mouse hematopoietic stem cells, or HSCs.
Although some modifications will be necessary for use with human HSC cultures, “once the changes are successfully made, the method is expected to facilitate treatment of blood diseases such as leukemia, because it can make a large quantity of HSCs available for transplantation into patients,” said Satoshi Yamazaki, project associate professor at the University of Tokyo and head of the team.
Conventional methods for culturing the self-renewing multipotent stem cells, which are found in bone marrow and can develop into blood-forming cells, use the expensive bovine serum albumin as a culture medium. The costly methods, however, cannot achieve a stable, long-term expansion of functional HSCs.
According to the Yamazaki-led team — also including researchers from the Japanese government-affiliated research institute Riken and Stanford University — and its article published online in the British scientific journal Nature on Thursday, the novel method uses a type of synthetic resin called polyvinyl alcohol as the culture medium.
A major raw material for liquid adhesives, polyvinyl alcohol is easy to obtain and is cheap.
Yamazaki and colleagues had previously found that albumin works to induce HSC division but that it also prevents the stable proliferation of the stem cells.
With polyvinyl alcohol, however, functional HSCs expanded up to 899 times over one month, according to the Nature article.
In addition, they confirmed that if a single HSC is available, the method will enable HSC transplantation into multiple individuals.