WASHINGTON - South Korean scientists have created the world's first human embryonic stem cells that are customized to injured or sick patients, a major step in the quest to grow patients' own replacement tissue to treat diseases.
These same scientists last year became the first to clone a human embryo, sparking international clamor. But those cloned stem cells - the building blocks that give rise to every tissue in the body- were a genetic match to a healthy woman, not a sick person. And it wasn't easy: It took 242 donated human eggs to grow just one batch.
Now the Seoul scientists have cloned patient-specific stem cells, important if doctors are to develop cell-based therapies that won't be rejected by the body's immune system. The technique worked with males and females, as young as 2 and as old as 56 - all suffering either spinal cord injuries, diabetes or a genetic immune disease, the researchers report in Friday's edition of the journal Science.
And the Korean lab found faster and safer ways to cull stem cells, using far fewer donated eggs - about 20 per try. They also eliminated use of mouse "feeder cells" that have been used to nourish most human stem-cell lines, thus easing concerns about contamination.