Initiation of Heterotopic Osteogenesis in Primates after Chromatographic Adsorption of Osteogenin, a Bone Morphogenetic Protein, onto Porous Hydroxyapatite

The chromatographic adsorption of partially purified osteogenin, a bone morphogenetic protein (BMP), onto porous hydroxyapatites for the construction of an osteogenic delivery system was investigated. Osteogenin fractions, with osteogenic activity in rats, were chromatographically adsorbed onto porous hydroxyapatites and implanted intramuscularly in baboons (Papio ursinus). Histology showed extensive bone differentiation within the porous spaces as early as 30 days after implantation in baboons. The unbound eluate from the porous hydroxyapatites showed lack of osteogenic activity when bioassayed in rats. These findings in primates may help to construct custom made porous ceramic as carriers for BMPs resulting in predictable bone formation for treatment of human bone defects.