title: In vitro bone formation on a bone-like apatite layer prepared by a biomimetic process on a bioactive glass-ceramic.
abstract: In this study we have investigated the behavior of fetal rat osteoblasts, cultured up to 23 days, on a bioactive apatite-wollastonite (AW) glass-ceramic and on the same material on which a carbonated apatite layer had been formed by a biomimetic process (AWa). At the last day of culture, the specific activity of alkaline phosphatase activity, as determined biochemically, was about 30% greater on AWa compared with AW disks. After the cell layers had been scraped off, scanning electron microscopic (SEM) observations of the materials' surfaces revealed that mineralized bone nodules remained attached to both surfaces but in larger amounts on AWa. X-ray microanalysis indicated the presence of calcium (Ca) and phosphorus (P) in the bone tissue throughout the AWa surface and Ca, P, and silicon (Si) on the AW surface. The AW/ and AWa/bone interfaces also were analyzed after fracturing of the disks. The interfacial analysis showed firm bone bonding to the AW and AWa surfaces, confirmed by the X-ray microanalytic mappings. These results indicate the importance of surface composition in supporting differentiation of osteogenic cells and the subsequent apposition of bone matrix, which allows a strong bond of the bioactive materials to the bone. Furthermore, prefabrication of a biologic apatite layer by a method that mimics biomineralization could find application to bone-repairing materials.
authors.affiliation: Laboratoire de Biologie-Odontologie, Faculté de Chirurgie Dentaire, Institut Biomédical des Cordeliers, Université Paris 7, 15-21 rue de l'Ecole de Médecine, 75270 Paris Cedex 06, France.
authors.forename: C
authors.initials: C
authors.lastname: Loty
authors.forename: J M
authors.initials: JM
authors.lastname: Sautier
authors.forename: H
authors.initials: H
authors.lastname: Boulekbache
authors.forename: T
authors.initials: T
authors.lastname: Kokubo
authors.forename: H M
authors.initials: HM
authors.lastname: Kim
authors.forename: N
authors.initials: N
authors.lastname: Forest
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001031:Apatites / Q000737:chemistry; D015415:Biomarkers; D018786:Bone Substitutes; D002478:Cells, Cultured; D002516:Ceramics / Q000737:chemistry; D004577:Electron Probe Microanalysis; D005333:Fetus; D008855:Microscopy, Electron, Scanning; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology*; D010012:Osteogenesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012824:Silicic Acid / Q000737:chemistry; D013499:Surface Properties
chemical_list: D001031:Apatites; D015415:Biomarkers; D018786:Bone Substitutes; C077777:apatite-wollastonite-containing glass ceramic; D012824:Silicic Acid; D000469:Alkaline Phosphatase