'Spare part heart' beats in lab

[Namelessv1]

The stripped-out shell of a heart has been made to work again - using brand new cells planted inside it.

Scientists removed all the muscle cells in a rat heart, leaving just a "scaffold" of other tissues such as blood vessels and valves.

When the University of Minnesota team added heart cells, they quickly grew and produced a pumping action.

It is hoped the Nature Medicine study will ultimately mean human or animal hearts can be crafted for transplant.Experts believe that failing organs in humans could in theory be replaced by new versions grown using stem cells.

These are the body's master cells, which have the potential to be transformed into any cell type in the body.

Any organ constructed in this way would have a significant advantage over donor organs for transplantation because they could be made to match the patient, and face a much smaller risk of rejection by the immune system.

However, one of the biggest obstacles to developing three-dimensional organs is finding a way to persuade cells to form the complex structures needed.

The Minnesota researchers decided that the best template would be another heart.

They took an adult rat heart, bathed it in detergents which removed all the cardiac cells, leaving a "frame" of other heart tissues forming the basic shape of the organ.

This frame was then "seeded" with cardiac cells taken from a newborn rat, and kept in lab conditions designed to simulate the growing heart.

Sunday, 13 January 2008, 18:01 GMT