The idea of improving human life through engineering replacement organs is not new. Aviator Charles Lindbergh experimented with the concept in the 1920s in an effort to help his ailing sister-in-law. Today, the need is even greater. Every 30 seconds, a patient dies from diseases that could be treated with tissue replacement.
The first success in patients occurred in 1981 with the use of skin cells to help burn wounds heal. There were few advances over the next decade because of a host of challenges, including the difficulty of multiplying cells outside the body. Once that obstacle was overcome, there have been multiple advances in the field. The world’s first engineered organ - the bladder - was implanted in 1998. In the past few years, teams have announced the implantation of engineered blood vessels, trachea and urethras in humans. The application of these treatments to small groups of patients through clinical trials illustrates the promise of regenerative medicine - to cure disease, not merely to treat symptoms.
What does the future hold? An important part of the answer is realizing that regenerative medicine isn’t a single technology or technique. For example, it can involve injecting functional cells into a damaged area of tissue to stimulate regeneration, such as injecting muscle cells to treat urinary incontinence. A second component is tissue engineering, combining either natural or synthetic materials with cells to build or print three-dimensional structures to support cells as they develop into tissue. A third component is using growth factors, genes, biomaterials or other agents to induce regeneration or self-healing.
It is likely that no one regenerative medicine technology is going to be best for all patients. One day, there will likely be a boutique of technologies that physicians and scientists can select from based on a patient’s needs. For example it is difficult to predict which form of regenerative medicine will eventually be used to help patients with damaged heart muscle. Will it be best to inject stem cells that will find their way to the damaged tissue? Or will we create patches of tissue in the lab that can be used to mend a poorly functioning organ? As we are pursuing solutions for patients, we should keep in mind that in many cases, we won’t need an entire new organ to dramatically improve the patient’s life. Many of our organs have a 90 percent reserve and can keep us alive when they are functioning at only 10 percent of capacity. So, our interest shouldn’t be specifically to build a human heart, or any organ for that matter, but to make patients better - no matter what strategy is used.
Nor should we expect that all hospitals and health care providers will offer these technologies. Instead, there will likely be a network of distribution centers to receive tissue samples from hospitals and prepare the appropriate cell therapy or tissue/organ for shipping back to the hospital.
There are many challenges to overcome, of course, before regenerative medicine therapies are commonplace. These include scientific challenges such as learning to grow the millions of cells that are needed to engineer a solid organ, and commercialization challenges such as obtaining regulatory approval and the huge expense of bringing new technologies to market. I do believe that these barriers will be overcome and that in the coming decades the promise of regenerative will be met - improving the quality of life for patients and helping to reduce health care costs.
Anthony Atala, MD, Director of Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA