It is believed the groundbreaking work by Durham University and the North East England Stem Cell Institute (NESCI), will accelerate progress on medicines for Alzheimer's and Parkinson's Disease sufferers.

And it could help reduce the number of animals used in laboratory research.

The project involved designing and developing new molecular tools for stem cell research to direct the formation of certain tissue types for use in drug development programmes.

Stem cells are a special type of cell that have the ability to renew other cells in the body.

One of the challenges facing scientists is to find out how these cells may be reprogrammed to become different tissue types.

The Durham team developed two synthetic molecules, EC23 and EC19, which can be used to coax stem cells to transform into other forms of tissue.

They were found to be far more stable than the naturally-occurring molecule used to induce stem cells to differentiate in the laboratory, known as All-trans-retinoic Acid (ATRA).

Their use will improve the reliability of experiments, said research team member and stem cell biologist Dr Stefan Przyborski.

He explained: "The key thing about these synthetic molecules is that they remain stable and are exactly the same every time you use them, ensuring more reliable scientific experiments compared to those which use ATRA.

"Because the results will be more scientifically robust, this will accelerate drug development using human stem cell-derived tissues and potentially reduce the numbers of animals used in such research."

The project was funded in part by Reinnervate, regional development agency One NorthEast, Durham University, High Force Research Ltd and NESCI.

The scientists, whose research has been published in the journal Organic and Biomolecular Chemistry, are now developing a molecular toolkit of synthetic compounds which are tailormade for specific stem cell and drug development work.