Stem cells can now be grown without using human or animal cells, by cultivating them on carbon nanotubes.

Stem cells are able to divide and renew themselves without limit. Under the right conditions, stem cells can create entire organs. These special cells are found in several organs, including the brain, liver, skeletal muscles and skin. When the structure is damaged, stem cells go into action, replacing the damaged tissue.

Specialized forms of these cells found in embryos can also form into any type of cell, from heart to bone or skin. Harvesting these cells from fertilized human eggs, called blastocysts, is highly controversial, and illegal in many countries.

Some stem cells are grown using animal proteins to guide their growth. However, such cells produced by this process cannot be used for humans. It is also not desirable to use samples from other people, as doing so can pass on diseases to the end recipient.

The breakthrough occurred when researchers cultivated stem cells on tiny carbon nanotubes. These microscopic structures serve as a platform on which the stem cells can grow. The human embryonic stem cells were grown on the tubes using the process of vacuum filtration. Researchers found the amount of energy applied when the cells were attached to the nanotubes had a significant effect on the future growth of the sample. They also found they could direct growth through the use of sound waves.

"While carbon nanotubes have been used in the field of biomedicine for some time, their use in human stem cell research has not previously been explored successfully," Alan Dalton, from the University of Surrey, said.

Medical researchers believe stem cells may soon be used to treat a wide range of diseases, disorders and injuries. Parkinson's disease, diabetes, The use of nanotubes as a replacement for the body's natural support structures could, one day, allow the cultivation of human organs in laboratories or hospitals. This could revolutionize medicine, saving thousands of lives every year. By using sound waves and other techniques to control the growth of the cells, solutions to many medical problems could be developed and grown, in a controlled manner.

"Synthetic stem cell scaffolding has the potential to change the lives of thousands of people, suffering from diseases such as Parkinson's, diabetes and heart disease, as well as vision and hearing loss. It could lead to cheaper transplant treatments and could potentially one day allow us to produce whole human organs without the need for donors," Dalton said.

The new discovery was funded by the Human Frontier Science Program, and the Royal Society, among other donors. Results were published in the journal Applied Materials and Interfaces.