What Is Bone Growth Factor? Definition and What Research Reports

Definition

Bone growth factor is a collective term used in the orthopaedic, dental and biomaterials literature for signalling proteins or peptides that stimulate the cells responsible for forming, mineralising and remodelling bone. Rather than naming one specific molecule, it functions as a category label: any polypeptide that acts on osteoblasts, mesenchymal precursor cells, or the fibroblastic cells of surrounding connective tissue to promote bone formation may be described this way. The term appears in paper titles across very different contexts — a milk protein studied for effects on bone cells (lactoferrin), a purified bone-derived extract used in spinal fusion (Ne-Osteo), and growth factors loaded onto ceramic or polymer carriers (IGF-I on tricalcium phosphate). Because of that breadth, the phrase is best read as a functional description of what a molecule does in bone, not as the identity of a particular compound.

This page is for educational purposes only and is not medical advice; consult a licensed physician for any question about a medical condition or treatment.

What Class of Molecule Is It, and Where Does It Come From?

Molecules grouped under this heading are almost always polypeptides or proteins — chains of amino acids that bind cell-surface receptors and change gene expression inside the target cell. Their origins vary:

• Blood and platelets. Platelet-derived growth factor (PDGF) is released during clotting and wound healing, and has been studied in combination with bone-substitute materials in a mineral-collagen graft model.
• Liver and local tissue. Insulin-like growth factor-I (IGF-I) circulates systemically and is also produced locally in bone; researchers have studied its adsorption onto and release from porous tricalcium phosphate implants.
• Demineralised bone matrix. Extracts purified from bone contain bone morphogenetic proteins; a bovine-derived extract of this kind was studied for posterolateral lumbar spine fusion.
• Milk and secretions. Lactoferrin, an iron-binding glycoprotein, was reviewed as a novel bone growth factor.

A related but distinct usage concerns growth factor receptors rather than the ligands. A 2024 review examined how growth factor receptors act in the spread of tumours to bone, describing them as central participants in cancer metastasis to the skeleton — a reminder that the same signalling systems that build bone are also studied in disease biology.

How the Term Is Used in Peptide and Biomaterials Research

In the published literature, "bone growth factor" rarely appears alone. It is usually attached to one of four research questions.

1. Delivery and carrier design

Because these proteins degrade quickly and diffuse away from a surgical site, much of the work concerns how to hold them in place. Researchers measured the adsorption and subsequent release of insulin-like growth factor-I from porous tricalcium phosphate implants, and a 2018 materials study described a PLGA film combined with titanium nanotubes as a sustained growth factor releasing system intended for dental implants. A separate group reported that a nanogel-crosslinking hydrogel used as a scaffold for bone growth factor induced osteoblastic bone formation.

2. Stimulating the body's own production

Some studies do not add a factor at all, but ask whether a physical stimulus changes how much the cells make. One laboratory study applied extracorporeal shock waves to human osteoblasts and fibroblasts and reported stimulation of bone growth factor synthesis in those cells. A Polish clinical report examined bone growth factor in women with osteoporosis exposed to a variable magnetic field.

3. Tendon-to-bone and soft-tissue healing

A recurring surgical question is whether a growth factor can make a tendon graft integrate into a bone tunnel. One animal study reported augmentation of tendon healing in an intraarticular bone tunnel with use of a bone growth factor, and a rabbit experiment examined the effect of bone growth factor on tendon-to-bone healing in anterior cruciate ligament reconstruction.

4. Measuring potency

Assessing whether a preparation is biologically active is itself a research problem. One methods paper used ultraweak photon emission to assess bone growth factor efficiency via fibroblastic differentiation.

What the Published Literature Reports

The evidence base is dominated by cell-culture and animal work, with a smaller number of small human studies. A 2005 review characterised lactoferrin as a novel bone growth factor, framing an established milk protein in skeletal terms. In the laboratory, shock wave application to human osteoblasts and fibroblasts was reported to stimulate bone growth factor synthesis in those cell populations. On the materials side, researchers described a nanogel-crosslinking hydrogel scaffold that induced osteoblastic bone formation when used to deliver bone growth factor, while a periodontal study reported that platelet-derived growth factor enhanced a mineral-collagen bone substitute.

In surgical models, an experimental rabbit study assessed bone growth factor in tendon-to-bone healing after anterior cruciate ligament reconstruction, and an earlier animal report described augmented tendon healing within an intraarticular bone tunnel. The clearest translational example combined species: a bone growth factor extract was studied for posterolateral lumbar spine fusion in both a nonhuman primate study and a prospective human clinical pilot study. Dosing quantities, carrier volumes and outcome rates differ substantially between these studies, and none of them establish a general protocol; readers interested in specifics should consult each abstract directly.

Related Terms at a Glance

Safety and Tolerability: What Studies Report

The verified literature summarised here is largely mechanistic, materials-focused or preclinical, and the abstracts centre on delivery characteristics, cell responses and healing outcomes rather than systematic safety reporting. The one study spanning animals and people examined a bone growth factor extract in a nonhuman primate model and a prospective human clinical pilot study of posterolateral lumbar spine fusion, which is a small pilot context rather than a large safety trial. Separately, a 2024 review described growth factor receptors as key participants in the metastasis of tumours to bone, which is why growth factor signalling is studied carefully in oncology as well as orthopaedics. No safety conclusions for any individual can be drawn from these reports.

Key Points

1. "Bone growth factor" is a category term, not a single named peptide.
2. The molecules involved are proteins or polypeptides from platelets, liver, local bone tissue, bone matrix extracts, or milk.
3. Most published work concerns delivery systems — ceramics, hydrogels, polymer films and implant surfaces such as PLGA film with titanium nanotubes for dental implants.
4. Human data in this specific literature set is limited to small pilot work in lumbar spine fusion and a clinical report in women with osteoporosis exposed to a magnetic field.

References

• Lactoferrin — a novel bone growth factor (Clinical Medicine & Research, 2005)
• Adsorption and release of insulin-like growth factor-I on porous tricalcium phosphate implant (Journal of Biomedical Materials Research, 2000)
• Stimulation of bone growth factor synthesis in human osteoblasts and fibroblasts after extracorporeal shock wave application (Archives of Orthopaedic and Trauma Surgery, 2011)
• The effect of bone growth factor in the tendon to bone healing in anterior cruciate ligament reconstruction: An experimental study in rabbits (International Journal of Applied & Basic Medical Research, 2016)
• Platelet-derived growth factor enhancement of a mineral-collagen bone substitute (Journal of Periodontology, 2000)
• The appreciation of bone growth factor in women with osteoporosis exposing on freetransition magnetic field (Polski Merkuriusz Lekarski, 2004)
• PLGA film/Titanium nanotubues as a sustained growth factor releasing system for dental implants (Journal of Materials Science: Materials in Medicine, 2018)
• Ultraweak photon emission in assessing bone growth factor efficiency using fibroblastic differentiation (Journal of Photochemistry and Photobiology B, 2001)
• From Tumor to Bone: Growth Factor Receptors as Key Players in Cancer Metastasis (Frontiers in Bioscience, 2024)
• Ne-Osteo bone growth factor for posterolateral lumbar spine fusion: results from a nonhuman primate study and a prospective human clinical pilot study (Spine, 2004)
• Augmentation of tendon healing in an intraarticular bone tunnel with use of a bone growth factor (The American Journal of Sports Medicine, 2001)
• Osteoblastic bone formation is induced by using nanogel-crosslinking hydrogel as novel scaffold for bone growth factor (Journal of Cellular Physiology, 2009)