Japanese scientists have shown that useful adult stem cells can be isolated from the human ear. The cells come from a part of the ear called the perichondrium, which is a thin layer of connective tissue that covers and protects cartilage in the human body. Previously another group had shown the regenerative potential of adult stem cells from rabbit ears, but the new study is the first to show such adult stem cells present in the human ear.

Prof. Shinji Kobayashi, lead author on the study published in the Proceedings of the National Academy of Sciences, and his colleagues discovered adult stem cells from the membrane that covers cartilage in the human ear. They developed a technique to grow the adult stem cells into cartilage efficiently, and found that the human stem cell-derived cartilage was stable for at least 10 months after it was transplanted under the skin of mice.

As the authors note in their published paper, there is great demand for effective treatments for craniofacial injuries or abnormalities, but effective treatments are currently lacking. Their discovery of this new, easily-accessible source of adult stem cells and their technique for efficient growth of cartilage would allow patients suffering from craniofacial deformities to be treated with reconstructive material grown from adult stem cells collected from their own ears. The scientists hope to start a clinical study as early as 2012.