~from The Guardian (you have to scroll down to the tenth paragraph to learn where the stems cells were taken). Hat tip to Off the Record.
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.
By using chemical and physical nudges, the scientists first coaxed stem cells extracted from bone marrow to grow into heart valve cells. By placing these cells into scaffolds made of collagen, Dr Chester and his colleague Patricia Taylor then grew small 3cm-wide discs of heart valve tissue. Later this year, that tissue will be implanted into animals - probably sheep or pigs - and monitored to see how well it works as part of a circulatory system.