American military researchers say they have unlocked the secret to regrowing limbs and recreating organs in humans who have sustained major injuries.
Using "nanoscaffolding," the researchers have regrown a man's fingertip and the internal organs of several test subjects.
The technology works by placing a very fine apparatus called a scaffold, which is made of polymer fibres hundreds of times finer than a human hair, in place of a missing limb or damaged organ. The scaffold acts as a guide for cells to grab onto so they can begin to rebuild missing bones and tissue. The tissue grows through tiny holes in the scaffold, in the same way a vine snakes its way up a trellis.
After the body part has regenerated, the scaffold breaks down, is absorbed into the person's body and disappears entirely.
The military plans to announce the breakthrough at the 26th Army Science Conference -- which attracts more than 1,600 international military scientists -- in Florida next month.
John Parmentola, director of research and laboratory management for the U.S. army, revealed some of the details of the announcement this week to a select group of bloggers and military observers on a conference call.
"There is a case of an individual who, with a model airplane, lost the tip of their finger," Parmentola told the group on the call. "And by the tip I mean the nail, the bone, the actual tip of their finger while they were starting up the airplane.
"That has been completely regrown . . . the nail, the bone, the tissue."
By using nanoscaffolding, the military was able to regrow the man's fingertip, restoring everything he had lost, much as some amphibians can regrow a leg or tail.
Parmentola said the military has been able to regrow "whole bladders" in people who have had bladder damage. The technology has also been used to repair the wall of a woman's uterus.
Several breakthroughs with nanoscaffolding preceded the U.S. army's stunning announcement. In June 2006, researchers from the University of Sheffield in England announced they had used nanoscaffolding to repair skin damage in people with third-degree burns.
Researchers attached a person's skin cells to a nanoscaffold, and the cells grew over it. The skin-covered scaffold was then placed over the wound, where it bonded with the patient's body. The scaffold then dissolved.
"Previous attempts to find better ways of encouraging skin cell growth have used chemical additives and other elaborate techniques to produce scaffolds, but their success has been limited," said Tony Ryan, a professor in the university's department of chemistry. "We've found that skin cells are actually very smart. It's in their DNA to sort themselves into the right arrangement. They just need a comparatively uncomplicated scaffold (and each other) to help them grow in a safe, natural way."
