A Briton has had millions of stem cells injected into his brain in a pioneering attempt to repair the damage caused by a stroke.
Another 11 patients will be treated with cells from an aborted baby from next month, as part of the world's first neural stem cell trial for the debilitating condition.
The revolutionary treatment could be in widespread use in as little as three years.
Incredibly, one 12-week-old foetus could generate enough cells to treat hundreds of thousands, if not millions, of patients.
But pro-life campaigners insist it is wrong to use an unborn child's life as a factory for spare medical parts.
More than a quarter of a million Britons live with a severe disability caused by stroke but there has been no way of healing the damage caused to the brain.
Doctors at Glasgow's Southern General Hospital and scientists at Surrey-based biotech firm ReNeuron believe the answer may lie in stem cells.
These are 'blank' cells capable of acting as a repair kit for the body by replacing worn-out tissue.
It is thought that a single jab could mend much of the damage caused by strokes, improving speech and walking and easing memory problems.
Last weekend, a truck driver in his 60s was given an injection of stem cells to the brain, as part of a preliminary trial to assess the safety of the procedure.
The man, who suffered a stroke 18 months ago, has been discharged and doctors say he is doing well. He is part of the first commercial stem cell trial to be held in the UK, in which four groups of three men aged 60-plus will receive progressively higher doses of the cells.
Doctors will monitor them for two years to see if the stem cells have started to repair their brains and if their condition has improved.
"We are pleased that the first patient in the trial has undergone surgery successfully," the Daily Mail quoted Dr Keith Muir, the Glasgow University expert leading the trial, as saying.