Animal studies at University of Michigan also show potential to restore sense of touch
Modern tissue engineering developed at the University of Michigan could improve the function of prosthetic hands and possibly restore the sense of touch for injured patients.
Researchers will present their updated findings Wednesday at the 95th annual Clinical Congress of the American College of Surgeons.
The research project, which was funded by the Department of Department of Defense, arose from a need for better prosthetic devices for troops wounded in Afghanistan and Iraq.
"Most of these individuals are typically using a prosthesis design that was developed decades ago," says Paul S. Cederna, M.D., a plastic and reconstructive surgeon at U-M Health System and associate professor of surgery at the U-M Medical School. "This effort is to make a prosthesis that moves like a normal hand."
U-M researchers may help overcome some of the shortcomings of existing robotic prosthetics, which have limited motor control, provide no sensory feedback and can be uncomfortable and cumbersome to wear.
"There is a huge need for a better nerve interface to control the upper extremity prostheses," says Cederna.
When a hand is amputated, the nerve endings in the arm continue to sprout branches, growing a mass of nerve fibers that send flawed signals back to the brain.
The researchers created what they called an "artificial neuromuscular junction" composed of muscle cells and a nano-sized polymer placed on a biological scaffold. Neuromuscular junctions are the body's own nerve-muscle connections that enable the brain to control muscle movement.
That bioengineered scaffold was placed over the severed nerve endings like a sleeve.
The muscle cells on the scaffold and in the body bonded and the body's native nerve sprouts fed electrical impulses into the tissue, creating a stable nerve-muscle connection.