Bone growth factor


A Bone Growth Factor is a growth factor that stimulates the growth of bone tissue. In certain studies, the addition of bone growth factors was seen to ameliorate the treatments of osteoporosis as well as tendon-to-bone healing.
Known bone growth factors include insulin-like growth factor-1, insulin-like growth factor-2, transforming growth factor beta, fibroblast growth factors, platelet-derived growth factor, parathyroid hormone-related peptide, bone morphogenetic proteins, and certain members of the growth differentiation factor group of proteins. According to menoPAUSE, a blog from University of Rochester, estrogen causes females to have their fat distributed in their breasts, thighs, and along their pelvic area, implying that the fat can be used as an energy source for future pregnancies. For men, androgens increases male's muscle-to-fat ratio.
Major hormones influencing bone growth and morphology include growth hormone, androgens such as testosterone and dihydrotestosterone, and estrogens such as estradiol. GH/IGF-1 are responsible for increasing overall body size, longitudinal bone size, and height, especially during puberty. Estrogens cause the hips to widen and become rounded during puberty in females, and androgens cause the shoulders to broaden in males. Estrogens mediate epiphyseal closure in both males and females. Other hormones implicated in control of bone growth include thyroid hormone, parathyroid hormone, calcitonin, glucocorticoids such as cortisol, and vitamin D.
Fibroblast growth factors are peptides that exists in two different forms, one acid and the other basic, having between them 55% homology. These factors are not proteins secreted into the environment, since they lack a signal peptide, which means that they are only released into the extracellular when the cell membrane is reorganized. Transforming growth factor beta is a physiological regulator of osteoblast differentiation, and acts as a central component in the coupling of bone formation and its resorption during bone remodeling.
Fibroblast growth factors and transforming growth factor beta have been successfully stimulated using extracorporeal shock wave therapy. Human fibroblasts and osteoblasts were shown to be capable of producing bone growth factors after stimulation. This method was researched as a solution for nonunion in orthopedic surgery.
Platelet-derived growth factors are polypeptides found in various tissues, including bone, where it was originally postulated that it could act as an autologous regulator of bone remodeling. This protein has been initially isolated in human platelets, and is composed of two different polypeptide chains A and B. The combination of these polypeptides form the homodimeric or, or heterodimeric chains of PDGF.
Bone Morphogenic Proteins are proteins that are made of acidic polypeptides. BMPs promotes the regeneration of bone tissue and cartilage. Bone Morphogenic Protein-2 works along with Vascular Endothelial Growth Factors in a complex cascade of signaling pathways to induce the regeneration of bone tissue. VEGFs works as angiogenic factors, whereas BMPs work as osteogenic factors. The dual combination of these factors can induce a system of vascularization in bones, which can help in bone repair and regeneration.
Bone Growth Factor on Possible Treatment of Osteoporosis
Osteoporosis is a bone disease where bone mass is less than the average and can increase fractures. Some causes that lead to osteoporosis is how old you are, and decreasing amount of estrogen, which is why it mainly occurs in older women.
During a recent study performed at Children's Medical Center Research Institute at UT Southwestern, Bone Growth Factor Osteolectin has also shown regenerative properties. Ovaries were removed from mice to simulate osteoporosis of post menopausal women. Results were based on daily injections of Osteolectin to determine the effects. This research showed an increase in bone volume of mice with bone loss after their ovaries were removed.
To be more specific, in order to help people with osteoporosis, medication is used along with treating bone fractures. Clec11a is a glycoprotein that bone marrow expresses which Elifesciences states.

Tendon Treatments Utilizing Bone Growth Factor

Several studies have shown a correlation between the administration of bone growth factors and the amelioration of the tendon-to-bone healing. The focus of these studies was primarily on the anterior cruciate ligament located in the knee, due to the high volume of incidences of injuries sustained by athletes. The University of Dammam, King Fahd Hospital in Saudi Arabia was able to show that the addition of SHMSP bone growth factor via powder facilitated the process of tendon-graft healing in rabbits. Comparison of this SHMSP test group to the control group illustrated a higher level of formation and organization within the knee.  
The Hospital for Special Surgery in New York conducted a similar study, in which a collagen sponge containing bone protein was implanted in the ACL of rabbits. In this case, the bone protein isolated from bovine femurs contained several bone morphogenetic proteins, which are part of an important signaling system that aides in the structure of bones. As with the application of SHMSP, the inclusion of bone protein in the collagen sponge was seen to improve the healing process, when compared to control groups with the sponge alone or no sponge.
In a separate study also implemented by the Hospital for Special Surgery as well as the University of California, treatment of the anterior cruciate ligament utilized the recombinant human bone morphogenic protein rhBMP-2 in two phases. In phase one, the dosages of noggin, a regulator protein, as well as rhBMP-2 were properly calibrated, and in phase two these proteins carried on synthetic calcium phosphate matrix were then injected into the ACL region. The results of this procedure also demonstrated an improvement in the collagen fiber formation between the tendon and the bone. Hence, all three treatments were seen to improve the efficacy of tendon-to-bone healing via the different bone growth factors: SHMSP, bone protein, and rhBMP-2.