Background: Bone morphogenetic proteins (BMPs) are also called growth and differentiation factors (GDFs) and form a subfamily of related proteins within the TGF-β superfamily. BMP-4 is one of multifuntional growth factors with pleiotropic roles in many different cell types and is predominantly present in human bone tissue.
Objectives: To analyze the content of extractable BMP-4 in human demineralized bone as a function of age
Material and Method: Bone samples were ground and demineralized by exposure to 0.5 N HCl and then extracted by collagenase digestion. Extractable BMP-4 was analyzed using a commercially available enzyme-linked immunosorbent assay (ELISA).
Results: 63 samples of demineralized bone matrix (DBM) derived from 36 men and 27 women between the ages of 15-65 years. The extractable BMP-4 content appears to be age dependent, with DBM from younger donors being most likely to have higher BMP-4 quantity. In addition, DBM with high osteoinductivity contained greater amounts of extractable BMP-4 than DBM samples with low osteoinductivity.
Conclusion: The BMP-4 in demineralized bone undergoes age-related decrease that may contribute to the reduction of bone volume observed with aging.

Keywords: Bone, Demineralized, BMP-4, Donor age, Osteoinductivity