nside bone in low concentrations, and in other parts of your body. They can be produced in higher concentrations through genetic engineering.
A lot of work is being done using genetic engineering to help with medical problems. Genetic engineering has made great improvements in making bone heal faster and better.
Genetic engineering can produce large quantities of a needed element in its pure form. During the genetic engineering process, signals inside a cell are altered in order to change the cell's function. To help with bone healing, cells can be turned into factories that produce growth factor proteins.
Growth Factor Proteins and Bone Healing
Growth factor proteins play an important role in the healing process. They call stem cells to the injury site. This is called chemoattraction. The stem cells are drawn to the injured area where they develop into "repair" cells.
Chemoattraction works only when there is a good blood supply around the injured area. If there is not good blood flow, the proteins cannot attract stem cells, or provide them with a way to travel to the area where they are needed.
Bone Morphogenetic Proteins
Many types of proteins aid in bone healing and can be produced with genetic engineering. The most powerful of these are bone morphogenetic proteins (BMPs). These synthetic proteins also help with muscle, tendon, and cartilage healing. Discovered during the 1960s, BMPs today are produced in large enough quantities to effectively speed the healing of damaged bone, especially in fractures that have a difficult time healing.
Of all the types of cells, stem cells have the greatest potential for promoting healing. As discussed above, stem cells are immature cells that are influenced by their surroundings. When brought to an injury site, a stem cell can develop into the kind of cell needed to help in healing - bone, muscle, ligament, and cartilage.
Because of the healing capabilities of stem cells, doctors have developed ways to bring stem cells to an injury site faster and in greater numbers. The first step in this process is to retrieve the stem cells. This can be done by harvesting them from the patient, or through a stem cell donor program.
Stem Cell Harvesting
There are many sources of stem cells in the human body. The most important source is bone marrow. Bone marrow is located in the centers of long bones, such as the bones in your arms, forearms, thighs, and legs. The pelvic bone contains the highest concentration of stem cells. Therefore, the bone marrow in your pelvic bone is the most common source for harvesting stem cells.
The doctor draws the stem cells out of the bone marrow with a needle, in a similar way that blood is drawn from your arm for tests. An orthopaedic surgeon then inserts this large supply of stem cells into the injury site. This eliminates the time it would take for the stem cells to reach the injury on their own and delivers them in a higher concentration, which speeds the healing process.
Stem Cell Donation
Orthopaedic surgeons can also use donor stem cells to promote healing. In much the same way that blood transfusions help millions of patients each year, stem cells taken from donors after they pass away help millions of orthopaedic patients. When these cells are harvested, they are treated so that they will not create an immune or allergic reaction in the patient.
Future of Orthobiologics
Each year, there are many new developments in the area of orthobiologics. For example, researchers are currently working on a "bone glue" that would not only fix fractured bones together, but also provide substances to aid the healing process. At this time, bone glues have not been proven effective, and there are none currently available. They have excellent potential in the future, however.
Today, doctors have many more options to help the musculoskeletal system heal than they had 15 years ago when most orthobiologics were not available. The goal is to get patients back to the way they were prior to their injuries.
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