Grown replacement parts will some day make body repair as commonplace as car repair.

A British research team led by the world's leading heart surgeon has grown part of a human heart from stem cells for the first time. If animal trials scheduled for later this year prove successful, replacement tissue could be used in transplants for the hundreds of thousands of people suffering from heart disease within three years.

Sir Magdi Yacoub, a professor of cardiac surgery at Imperial College London, has worked on ways to tackle the shortage of donated hearts for transplant for more than a decade. His team at the heart science centre at Harefield hospital have grown tissue that works in the same way as the valves in human hearts, a significant step towards the goal of growing whole replacement hearts from stem cells.

Yacoub thinks his team might be able to grow a complete heart within 10 years. That's 2017. So if you need a new heart in 2025, no problem - at least if you can afford it. But if full replacement hearts become possible by, say, 2020 (add a few years for complications along the way) then why won't all the other organs follow shortly thereafter? By the year 2030 should anyone in an industrialized country die from internal organ failure? It seems totally avoidable.

Next throw in some stem cell therapies that repair blood vessels and muscles. We''ll also need therapies to repair immune cells. That will leave the last great rejuvenation frontier: the brain. Can't replace that. Need to repair the existing cells. Brain rejuvenation is the hardest challenge of all. For that we'll need excellent gene therapy and nano repair devices. I hope many of us do not become too brain aged and dumb before such therapies become available.