title: Evaluation of a novel osteogenic factor, bone cell stimulating substance, in a rabbit cranial defect model.
abstract: A novel osteogenic factor, bone cell stimulating substance (BCSS), was recently isolated from bovine bone. Unlike the bone morphogenetic proteins, which are generally 20- to 40-kDa glycoproteins belonging to the transforming growth factor-beta superfamily, BCSS is a 2.5-kDa, water-soluble polypeptide. This study evaluated the osteogenic potential of BCSS in combination with coralline-derived porous hydroxyapatite to reconstruct a large, nonhealing cranial defect in the rabbit. Twenty-four rabbits underwent a 16 x 20 mm full-thickness (extradural) excision of the parietal bones and were divided into six groups of four rabbits each. Group 1 through 5 were reconstructed with 16 x 20 x 1.5 mm hydroxyapatite implants treated with: (1) 20 osteogenic units (424 micrograms) BCSS, (2) 8 osteogenic units (170 micrograms) BCSS, (3) 4 osteogenic units (85 micrograms) BCSS, (4) 0 osteogenic units (424 micrograms) inactive BCSS analog, or (5) left untreated. Group 6 was left unreconstructed. Implants were harvested at 12 weeks and analyzed for percentage of lamellar bone formation by a computerized microscope video image analysis system. Groups reconstructed with BCSS-treated hydroxyapatite implants demonstrated more bone ingrowth than did the control hydroxyapatite groups not treated with BCSS (inactive BCSS analog or untreated). Linear regression dose-response analysis indicated an average 3.2 percent increase in bone ingrowth for a 10-U increase in BCSS (p = 0.043). The unreconstructed control group demonstrated no healing. With a molecular mass of only 2.5 kDa and its identity not completely known, BCSS is a novel factor that seems to possess osteogenic potential similar to that of previously investigated osteogenic proteins.
authors.affiliation: Research Service, West Los Angeles Veterans Administration Medical Center, California, USA.
authors.forename: E R
authors.initials: ER
authors.lastname: Ashby
authors.forename: G H
authors.initials: GH
authors.lastname: Rudkin
authors.forename: K
authors.initials: K
authors.lastname: Ishida
authors.forename: T A
authors.initials: TA
authors.lastname: Miller
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes; D001842:Bone and Bones / Q000473:pathology; D004195:Disease Models, Animal; D016503:Drug Delivery Systems; D017886:Durapatite / Q000627:therapeutic use; D005069:Evaluation Studies as Topic; D005260:Female; D006133:Growth Substances / Q000494:pharmacology; D010012:Osteogenesis / Q000187:drug effects*; D010455:Peptides / Q000494:pharmacology* / Q000627:therapeutic use; D019736:Prostheses and Implants; D011817:Rabbits; D012886:Skull
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D006133:Growth Substances; D010455:Peptides; D017886:Durapatite