Bubenik is studying how scientists can use the embryonic stem cells that induce antler regrowth in white-tailed deer to treat human ailments. Human applications could include the eventual regrowth of fingers and limbs, as well as treatments for arthritis, immune disorders and degenerative diseases such as osteoporosis.

  "The growth of deer antlers is one of the wonders of nature, and it has great potential for use in medicine," says Bubenik, a medical doctor who taught medicine in Switzerland and worked in the Department of Neuroendocrinology at Toronto's Clark Institute of Psychiatry before joining U of G in 1977.

  All deer shed their antlers each year, and the presence of embryonic stem cells in the antler allows for regrowth of antlers, differentiating into skin, blood vessels, cartilage and bone. "This is what makes them unique among mammals," says Bubenik. "Deer antlers can grow up to two centimetres a day. In other mammals, including humans, only tumours or embryos are able to grow new tissue at such a fast rate."

  Deer antlers are strikingly similar to human limbs, consisting of bone, cartilage, skin, blood vessels and nerves. The key to humans regrowing severed limbs or fingers may simply be a matter of understanding the formation and function of the embryonic stem cells that occur in antler regrowth, Bubenik says.

  "It's a very complex question that involves biochemistry, endocrinology and cell physiology. Once we understand it and can initiate the presence of embryonic stem cells in mature tissue, we can stimulate the regrowth of limbs in other animals and humans."

  As a first step, Bubenik is collaborating with researchers in Germany to study the role deer antler embryonic stem cells might play as a model for treatment of osteoporosis. The scientists have learned to grow the embryonic stem cells in tissue cultures. This means the supply of stem cells is unlimited because they are frozen and restarted again.

  Next, the researchers studied the effect of certain male and female hormones on the growth and differentiation of antler stem cells.

  "Our goal is to create cells that will differentiate into other tissue if implanted into that part of the body," says Bubenik.

  Deer antler stem cells could be injected directly into areas where tissue needs to be regenerated, restoring the function of cartilage in areas of the body such as the knee and elbow, or to facilitate the regeneration of broken bones.

  "I believe that in a few years, we will be capable of regrowing cartilage, bones, skin and even nerves from these embryonic stem cells," says Bubenik.

  The hope is that this research will lead to developments that will eventually allow humans to regrow severed fingers and even entire limbs. "The possibilities could be limitless."