Blood vessels made from stem cells

Scientists from the Massachusetts Institute of Technology (MIT) in the US have announced that they have successfully made human embryonic stem cells form themselves into fully-functioning blood vessels.

The research, published in the Proceedings of the National Academy of Sciences, suggests that the cells could be used to repair damaged heart tissue and clogged arteries.

Dr Robert Langer and colleagues adopted a 'hands-off' approach to the research, which is thought to be a 'first'. They placed stem cells derived from human embryos in culture and watched them divide. Some of the cells seemed to show a predisposition for differentiating into blood vessels cells, so these were separated from the others and allowed to grow. It was seen that they developed into 'primitive' blood vessels.

The primitive blood vessels were transplanted into mice which had had their immune systems disabled to avoid rejection. Within 14 days, the cells had developed into capillaries which appeared to contain mouse blood cells, suggesting that they were fully functioning. According to Dr Langer, the technique, once developed further, could potentially be used to replace diseased arteries or to restore circulation to cells damaged by heart attacks.