New cell therapy for stroke patients

A UK biotech firm, ReNeuron, is developing a new treatment for stroke that involves a single injection of neural stem cells - cells that can grow into a variety of different nerve and brain cells. If clinical trials are successful, the company hopes to develop similar therapies for Parkinson's and Alzheimer's disease.

Dr John Sinden told the British Association's Festival of Science last week that the company plans to begin clinical trials involving a small number of patients next year. The stem cells were grown in the laboratory, using material taken from an aborted fetus. The resulting cell-line has been genetically altered to prevent the cells multiplying once they are injected into the body: the researchers inserted a gene that permits the cells to divide at 33°C, but not at 37°C, human body temperature.

The scientists will inject around ten million stem cells through the skull, into the area of the patient's brain damaged by the stroke. Once in place, it is hoped the cells will develop into the required types of brain cell and restore brain function. Experiments using animals have shown that the stem cells can regenerate areas of damaged brain responsible for muscle control.

Meanwhile, scientists at University College, London published more evidence for the versatility of neural stem cells in last week's Science. Toru Kondo and Martin Raff have managed to turn rat oligodendrocyte precursors - cells destined to become nerve 'support' cells - into neurons, nerve cells that carry electrical impulses. While the results indicate that the developmental clock in some cell types can be turned back, Kondo warns that realising the findings' potential could take many years.