Bone of invention

A technique that uses electrical current to engineer human tissue could one day be used in the treatment of bone marrow diseases such as leukaemia.

The technology, pioneered at Manchester University, uses electric fields to build up layers of cells to gradually form tissue and the researchers behind the project believe it could lead to the creation of artificial bone marrow in a laboratory.

Dr Gerard Markx from the university’s school of chemical engineering and analytical science is leading the project. He has been working to create haematons, or aggregates of blood-producing cells that are crucial to the development of healthy bone marrow.

People with bone marrow diseases typically lack fully functioning haematons. Early results have led to the creation of haematon tissue, which is around 200 microns thick.

Key to the development has been the use of extremely small custom-built electrodes that are created using a technique known as photolithography.

These micro-electrodes — about 30–300 microns in size — are made by etching channels into glass slides in the same way semiconductor devices are etched into silicon.

The cells are grown specially in suspension and then put into a buffer solution before being introduced between the electrodes. An electric field is then created between the electrodes by introducing small AC current through them.

As the cells collect in different areas between the electrodes researchers have found that they can manipulate the way in which they build up to form tissue.

‘Any cell in the vicinity of the electrodes is attracted towards them as well as in the space between them,’ said Markx. ‘By switching the electric field between the different electrodes and changing it from low to high you can create a number of different effects on the tissue cells. You can play around with the frequency and voltage and build up the cells in different ways.’

He added that by using electric current not only can the cells be accurately controlled but they are also kept alive and active, which is crucial for the creation of healthy tissue.