Body Builders

The field of tissue engineering has long been fraught with hope and hype. For the past several decades, laboratory scientists have pursued the ambitious goal of growing new organs and tissues—a heart, say, or a piece of spinal cord—that a surgeon could transplant into a patient. This capability could potentially solve the chronic shortage of donor organs while offering physicians new ways of treating patients with diseased and damaged tissues, such as knees or hips ravaged by arthritis.