Researchers Use Stem Cells to Repair Vocal Cords
Mon Jun 17, 5:28 PM ET
By Alison McCook

NEW YORK (Reuters Health) - Researchers in Japan have successfully repaired damaged vocal cords in dogs using stem cells collected from the animals' own body.

During a presentation here on Friday, Shin-ichi Kanemaru of Kyoto University in Japan described an experiment in which he and his colleagues repaired damaged vocal cords in dogs by injecting them with their own stem cells, extracted from the dogs' bone marrow.

"Regeneration of the vocal cord by this technique is a possible treatment for the injured vocal cord," Kanemaru announced here during the 48th Annual Conference of the American Society for Artificial Internal Organs.

Using adult beagles, Kanemaru's team created a mixture of stem cells from bone marrow and collagen gel. The researchers injected the mixture into the left side of the dogs' damaged vocal cords, then just collagen into the right side of the vocal cords, to compare the progress.

After the dogs received the injections, the investigators found that the left side of their vocal cords was much improved relative to the right. And the differences between the sides appeared to widen over time: One year after the experiment, the researchers concluded that the dogs had improved enough on the left side to use their vocal cords again.

This technique could be used to help reverse the effects of many causes of vocal problems, Kanemaru said. When vocal cords become damaged, the researcher explained, the injury may become healed over with scar tissue, which can leave the patient mute, or with swallowing difficulties. In addition, as people age, vocal cords can atrophy, becoming thinner.

In an interview with Reuters Health, Kanemaru said that he and his colleagues plan to begin clinical trials of the technique, enrolling patients who suffer from damaged vocal cords.

He admitted that extracting stem cells from bone marrow "could be very painful for the patient," but that doctors would only require 2 milliliters of bone marrow cells to obtain the stem cells they need.

Stem cells collected from bone marrow are immature cells that can give rise to blood and immune systems cells. Some studies have suggested that the cells may also have the potential to turn into mature cells in other types of body tissue.