The Kyoto University School of Medicine researchers used a 15-millimeter silicon tube to product the transplanted bone marrow cells, or BMCs, and adult stem cells, nourishing them with bio-engineered materials. The result, said the scientists, might provide an important step in developing artificial nerves.

"We focused on the vascular and neurochemical environment within the tube," said Dr. Tomoyuki Yamakawa, the study's lead author. "We thought that BMCs containing adult stem cells -- with their potential to differentiate into bone, cartilage, fat, muscle, or neuronal cells -- could survive by obtaining oxygen and nutrients, with the result that rates of cell differentiation and regeneration would improve."

Nourished with bioengineered additives, the BMCs after 24 weeks differentiated into cells with characteristics of Schwann cells -- a variety of neural cell that provides the insulating myelin around the axons of peripheral nerve cells.

The new cells successfully regenerated axons and extended their growth farther across nerve cell gaps toward damaged nerve stumps, with healthier vascularity.

The research is detailed in the current issue of the journal Cell Transplantation.