By Rebecca Jones
Imagine a world where humans could regrow lost or damaged limbs, where organs can be grown in a lab with the cellular DNA of their future recipients. This might sound like science fiction but researchers all over the country are working to make regenerative medicine a reality. From regrowing finger tips to replacing kidneys, giant steps are already underway. Ears, bladders, even a beating heart have already been generated and at Wake Forest Institute for Regenerative Medicine twenty-two different tissues and organs are under development. How are these miracles being performed and what can it mean for the future of health care?
Currently there are two methods for creating replacement tissues and organs. The first involves creating a 3-dimensional mold of the required body part. Every organ in the human body contains stem cells. Each of these cells not only knows what function to perform in the body but contains all of a person’s genetic information. Once these cells are isolated they are brushed onto the mold one layer at a time and over a 6-8 week period, as the cells multiply and tissue forms, the mold will degrade. At the end of this period you are left with an organ, that unlike prosthetics, will be recognized by the human body. For example an ear bio-engineered for a child will, once attached, continue to grow as the child ages. Already doctors have successfully grown and transplanted livers in mice and with plans to generate heart valves and blood vessels in the near future the application of regenerative medicine is virtually limitless.
Just as a salamander or starfish can regrow a lost limb, so are scientists developing the technology to regenerate growth in the human body. In the very early stages of human gestation the fetus is capable of repairing and regenerating damaged body parts. If we could turn the switch for this ability back on in adults it would change the entire human healing process. This might sound far fetched but children as old as two have been known to regrow finger tips so we know that the potential is already within us. Researchers are turning to the extracellular matrix (ECM) as our best hope of regeneration. Part of all animal and human tissue, the extracellular matrix consists mainly of collagen and works in conjunction with stem cells to provide instruction and structural support to cells. Doctors have turned to pig bladders as a readily available source of ECM. Since it does not actually contain pig DNA it is already been used to generate healing in humans. Normally when the human body is injured the immune system creates scar tissue that stops all cell growth but if ECM is inserted into the wound scarification is prevented and new cells can began to generate. Already tests are being done on soldiers who have been injured in bomb blasts. Powdered ECM is applied to wounds in the hopes of generating new muscle growth. In another test a sleeve of ECM was inserted into the esophagus of a patient who’d had a cancerous lining removed. Instead of developing scar tissue that would have created a blockage the ECM instructed his cells to grow a whole new lining allowing a full recovery.
Although it might be several years before regenerative medicine becomes readily available the medical community is excited about its many practical applications. In a future that even Shelly’s Frankenstein could not have envisioned, we will be able to not only rebuild our bodies but spare ourselves the devastation of losing loved ones to injury and organ failure.