Improved culture media could advance stem cell research
use in fertility clinics, has developed a protein-free cell culture
medium that could cut out problems associated with current media.
The new product - called SSR - performs as well as current products in growing stem cells, but should avoid variation between growth batches and make stem cell culture more reliable and reproducible. In essence, the key to the SSR formulation developed by Medicult is a fully synthetic replacement for human serum albumin (HSA), which is included in all culture media used to cultivate human stem cells at present. HSA is derived from human serum and fulfils a valuable function in protecting fragile growing cells, but also has disadvantages. For example, it can often harbour trace amounts of growth factors and other elements that can influence the growth of cells, and this can mean that the growth of one batch of cells will differ from another even if carried out under the same conditions. There is no chance that this can occur with Medicult's SSR formulation, according to the firm's CEO, Jesper Funding Andersen. "To the best of our knowledge, there is no HSA-free media available for cultivating stem cells yet," he said in an interview, adding that finding media which provide highly-reproducible results will be critical if stem cells are to emerge from the lab and be used in therapeutic applications. Proof-of-concept studies carried out internally at Medicult have already shown that the medium can keep stem cells viable for at least three months and, critically, that they can be maintained in an undifferentiated state over the period and retain their ability to subsequently differentiate into specialised cell types. Andersen noted that the rate of cell division is a little bit lower than with HSA media, but not to an extent that will affect typical applications in stem cell research. The next stage for Medicult is to get external laboratories to reproduce and hopefully validate the internal proof-of-concept studies, according to Andersen. "Our impression so far is that the performance with this adult stem cell formulation is sufficient for current applications," said Andersen, adding that additional work will now be undertaken to refine the SSR formulation so that it is suitable for embryonic stem cells. While there is intense development of all three major types of stem cell - adult, embryonic and cord blood cells - Andersen believes that embryonic stem cells will play the greatest role, particularly in therapeutic applications. "The timeline is shortening for the first applications of stem cells to arrive, perhaps in as little as two to three years," he said. And while the commercial market for stem cells in research, drug discovery or therapies is still in its infancy and tough to predict, the likelihood is that it will be substantial. "The growing use and diverse applications of stem cells are having a significant impact on the media market," said Andersen. "We believe that the possibility to make protein-free media is the key differentiator to other currently available stem cell media and that this will impact significantly the potential to develop the area, particularly as the regulatory environment continues to evolve." The first results from this validation work should come through by the end of the year, with the embryonic stem cell data due in early 2008, and the commercial potential of the culture medium will remain unclear until that time. Andersen said the likelihood is that, if all goes to plan, Medicult will try to license out the technology to one of the top players in the cell culture media market rather than try to bring it to market alone. At the moment this approach would put the likes of Hyclone, Invitrogen and Novozyme into the frame, but there are between eight and 10 companies which are already producing media designed for use with human stem cells. Medicult is currently at the stage if producing small batches of the medium and, because it is not possible to manufacture media for stem cell applications in the same facility as media for in vitro fertilisation techniques, Medicult will have to build another manufacturing facility or turn to a contract manufacturer if it wants to scale up production in-house.