Stem cells are the body's master cells. They are formed shortly after fertilization and have the potential to turn into any kind of cell. This kind of flexibility makes them a valuable tool for researchers looking to treat or cure some of the most severe diseases that plague us.
There are many different kinds of stem cells but the two broad categories are adult and embryonic. Scientists are trying to understand how they differentiate, that is change into specialized cells, be they heart, liver, kidney or brain for example. Once this process of stem cell research has been fully understood and mastered, stem cells could be used to replace ageing, failing and diseased tissue. Theoretically a patient with heart disease could be injected with new heart cells that have been cultured in the laboratory from a collection of stem cells.
However, one of the stumbling blocks so far has been the difficulty of turning stem cells into the specific cells required, and for them to stay that way for long periods of time. They need the correct concentration of chemicals to be delivered at just the right time under an exacting set of conditions. Researchers at Durham University in Scotland reckon they have a solution up their sleeve.
Writing in the Organic and Biomolecular Chemistry journal, the team have just announced (September 2008) the creation of 2 synthetic molecules that can coax stem cells to differentiate along desired pathways, providing a valuable boost to stem cell research.
The molecules are called EC23 and EC19 and were found to be much more stable and robust than the molecule used at the moment, ATRA (All-trans-retinoic Acid). Scientists claim that their new chemicals will boost the reliability of experiments, which will result in far fewer animal models being used.
The team tested EC23 and EC19 on 4 different types of stem cells.
EC23 was successful in turning stem cells into neurons, and these could be used for testing the efficacy and safety of drugs for neurodegenerative diseases such as Parkinson's.
EC19 was found to be good at turning stem cells into epithelial cells, the cells that line the inner and outer cells of the body. There's potential here for the treatment of burns victims.
ATRA has been shown to be sensitive to light and degrades under such a condition, making it hard for scientists to know exactly the concentrations needed to direct stems cells to grow into particular types of tissues. Not so EC23 and EC19, which were more robust, and did not degrade under laboratory conditions.
The success of the research astounded scientists. Team member and synthetic chemist Dr Andrew Whiting observed: "We've set out to make stable mimics of natural compounds which control development, but in this case, not only have we uncovered a compound which is not only stable and does what the natural system does, but it actually seems to be better as well. It's a real bonus and shows the validity of the approach."
In fact EC23 produced 40 per cent more neurons than ATRA.
The aim is now to use these synthetic molecules in drug development programmes and to devise other molecular toolkits that can be used to harvest specific tissues from stem cells. This research will also be of great value to those scientists trying to overcome the tricky problem of creating specialized cells for the potential treatment of patients with severe medical problems.