Written by Laura Miller | October 06, 2011
Throughout his career, Hyun Bae, MD, co-director of the spine fellowship program and director of education at Cedars-Sinai Spine Center in Los Angeles, has been working with regenerative medicine, especially as it relates to the spine. He was among the first surgeons to use growth factor tissue engineering for intervertebral discs and multi-level artificial disc replacements for the lumbar and cervical spine. While for many surgeons, utilizing stem cells in may seem revolutionary, Dr. Bae’s goals are simple: focusing on basic science and transitioning findings to his patients.
“My focus has been working to bring basic science research into the clinic,” says Dr. Bae. As a clinician researcher, I want to bring my research to the patients as soon as possible.”
Dr. Bae works with stem cells in his lab and he feels the appropriate patients could benefit greatly from their use. “I think stem cells will make a big impact on spine care,” says Dr. Bae. “I don’t think this is some mythical soundscape that won’t work. I think in the next 10 years, stem cells will make a significant impact on our medical field.”
Dr. Bae is participating in several clinical trials for spine surgery with exciting results:
1. Injecting stem cells for disc regeneration. For select patients with back pain, injecting stem cells into the dark disc could promote disc regeneration, which would relieve the patients’ pain without fusion procedures. The clinical trials have been successful in animal models and are now being used in a human trial.
2. Gel injections. Injecting gel, or fibrin glue, into the patient’s spine can stimulate an initial cascade of healing. In patients with an annular tear, the surgeons are using a fibrin glue to close the disc and promote healing instead of fusing it or removing it. For this trial, the surgeons are injecting fibrin glue in half of the patients and a placebo in the other half to measure the glue’s efficacy. Dr. Bae has not been un-blinded with the patients, but is still surprised with the success some patients are exhibiting. “Some of the patients have had amazing results,” he says. “I’m surprised because initially I was skeptical, but I’ve been amazed.”
3. Stem cells for treating vertebral compression fractures. Dr. Bae and his colleagues are using a grant from the California Initiative for Regenerative Medicine to develop a method for treating vertebral compression fractures in patients with osteoporosis using stem cell injections. The team received $2 million to examine the treatment in small animals and is currently seeking $20 million to begin testing the technique in pre-clinical trials. “Hopefully, in four years we’ll be able to use this method with our patients,” says Dr. Bae.
For this new method, surgeons transport allograft stem cells to the surgical site. The stem cells are manipulated by non viral methods to produce a bone morphogenic protein-type molecule, which should promote healing. “We want the stem cells to produce a growth factor that can also stimulate healing,” says Dr. Bae. “We’ve shown in animal models that we can insert a gene into the cells that will be able to produce bone. We can heal a radial, vertebral body or long bone defect by injecting stem cells into the surgical site that have been modified to produce bone.”
In the future, Dr. Bae hopes to research this method with patients who have osteoporosis. These patients have global bone loss, but there are certain sites where the loss is more significant. “We may not be able to cure the entire body, but if we are able to inject stem cells into a damaged site like the hip joint, we may be able to prevent the major fracture morbidity associated with osteoporosis,” says Dr. Bae.
Receiving FDA clearance
There are several orthopedic and spine research centers around the country conducting research on stem cell treatments, and Cedars-Sinai is one of eight centers where surgeons are examining the use of stem cell injections for disc regeneration. However, most devices and procedures utilizing stem cell technology are not approved by the Food and Drug Administration yet.
“One of the biggest challenges we will face in making stem cell therapy more widespread is the regulatory hurdle,” says Dr. Bae. “The FDA isn’t doing anything wrong, but they want to make sure all devices and procedures are safe. Will we overcome this hurdle? Absolutely — we will be able to show the results are good enough that the FDA will fast track it. Once the FDA sees the trial results, they’ll want to get stem cell therapies out to patients.”
Stem cells don’t have a limited lifecycle; they can divide and become what you desire. They can produce local growth factors that can help bone heal and could potentially be modified to have a more global effect.
“We are really trying to parse out all the hype surrounding stem cells to see what is effective and what is just hype” says Dr. Bae. “In the case of California, scientists and government officials are both heavily invested in stem cell research. We really feel like we are on the cusp of something big. I believe in the near future, we will have major breakthroughs in stem cell therapies for treatment of human diseases.”
Related Articles on Spine Surgery:
Restoring Function After Spinal Cord Injury With Nerve Transplant: The New Frontier
3-Column Osteotomies of the Spine: Q&A With Dr. Michael Chang of Sonoran Spine Center
Scoliosis as a Neurological Condition: 4 Points on Two New Genes Making the Connection
Health & Science
POSTED ON JULY 22, 2010, AT 5:51 PM
Black sprinters’ navel advantage
To size up a sprinter’s potential speed, start by examining his navel. That’s the conclusion of researchers at Duke University, who dared to examine the historically verboten question: Why do Africans and African-Americans tend to run faster than whites? The answer, says Science Daily, lies with the bellybutton, which marks the body’s center of gravity. An analysis of prior studies of human measurements revealed that, on average, people of West African origin have longer legs than people with European heritage; the longer legs, and shorter torsos, place their center of gravity 3 percent, or roughly an inch, higher. Collating a century’s worth of sprinting records revealed that this height difference translates into a 1.5 percent boost in speed—enough to make a big difference in the results of sprints, in which fractions of a second separate winners from losers. “Locomotion is essentially a continual process of falling forward, and mass that falls from a higher altitude falls faster,” says research leader Andre Bejan. The converse holds true for swimmers: Europeans have a 3 percent longer torso than West Africans, which equals a 1.5 percent speed advantage in the pool. The researchers were careful to note that they focused on the athletes’ geographic origins and physical measurements, not race, which they deem a “social construct.”