A 14 year old boy’s missing facial bones have been regrown with the help of his own stem cells. The procedure, led by Jesse Taylor, MD, a surgeon and researcher at Cincinnati Children’s Hospital Medical Center, represents the culmination of years of work that first began on pigs. The technology appears to be general enough that it may have the potential to grow almost any bone in the human body, possibly revolutionizing treatment for tens of millions of people across the world suffering from severe bone disorders or damage. The procedure represents one of a growing slate of successes that are moving stem cells from pie in the sky dreams to real world therapies. See the video at the end of this post.
Lets try to explain the procedure as cleanly as possible: These new stem cell derived bones are not grown 100% from the ground up with stem cells. Instead donated bone is first molded into the precise shape of bone that the patient requires, serving as a scaffold for the stem cells to grow upon. Holes are then drilled into this bone scaffold and mesenchymal stem cells taken from the patient’s abdominal fat along with a growth factor known as morphogenic protein-2 (BMP-2) are inserted into the holes. BMP-2 is a critical protein within the body responsible for signaling mesenchymal stem cells to proliferate and differentiate into bone cells. The bone scaffold filled with mesenchymal cells and BMP-2 is then wrapped in a thin membrane of tissue that naturally coats human bone surfaces called periosteum. The periosteum used in this surgery was taken from the patient’s thigh. Periosteum is important to the body’s normal production of BMP-2, and just as vital to providing a blood supply to nourish new bone formation. This periosteum wrapped scaffold infused with mesenchymal cells and BMP-2 is surgically implanted into the patient and over time the stem cells grow over the scaffold to create real, healthy, functioning bone in the patient.
The teenage recipient of the surgery, Brad Guilkey, has a rare genetic condition known as Treacher Collins syndrome, which caused him to be born without zygomatic cheek bones responsible for providing prominence and support around the bottom of the eye sockets. The condition had left Guilkey with droopy looking eyes and cheeks that he had attempted to partly hide with his long hair. In addition to affecting his looks, the condition left Guilkey in constant danger of severely injuring his eyes since they were not protected by the missing cheek bones. Now with the new cheek bones in place it is heart warming to see this now 15 year old boy looking and feeling normal enough that he has given up on the face hiding hair.
Although metal and other synthetic materials can sometimes be used as replacement parts for damaged or missing bones, real living human bone is still by far the best solution when possible. As with all stem cell treatments derived directly from the patient, one of the greatest features of the procedure is that there is no risk of immune system rejection of the new bone since the cells are the patient’s own.
Four months after Guilkey’s procedure a CT scan indicated that the cheek bones had filled in normally with healthy bone, but it unknown how the bones will evolve and maintain themselves over the course of several years and beyond. Only time will reveal such answers.
In the meantime at least two other patients have already undergone a similar procedure and more aggressive tests continue on bones of different sizes and lengths within pigs. According to Cincinnati Children’s a research paper is being prepared for peer-review journal publication, describing the use of the procedure to grow viable, dense bone in pigs and the duplication of results numerous times. The researchers worked with pigs because their immune systems are very similar to that of humans, making the animals a good model for simulating engineered bone growth in people.
Perhaps one of the more bizarre elements of the entire procedure is that the doctors really don’t know how or why the stem cells work their magic. Other than helping things along with BMP-2, the doctors are pretty much letting natural biological signalling and decision trees within the human body regulate the growth of this bone. The phenomenon of not really knowing how the stem cells actually work is in fact common among most of the stem cell procedures being attempted across the world today. Given the amazing ability of stem cells to morph into pretty much any type of cell within the body researchers are squirting these little miracles into spinal fluid, brain tissue, bone – anywhere they can – to see what happens.
We are still in the dark ages of a bright future for stem cell therapy. Even with the current “throw in the stem cells and see what happens” techniques of today new bones are being grown and eyesight is being restored to the blind. As researchers continue to study and unravel the secrets of stem cells the advances will only become more impressive. In the next several decades it is entirely conceivable, in fact likely, that we will be able to have several different types of replacement organs and tissues custom grown for our bodies. The Methuselarity may indeed be within our reach!