title: Osteogenecity of octacalcium phosphate coatings applied on porous metal implants.
abstract: The biomimetic route allows the homogeneous deposition of calcium phosphate (Ca-P) coatings on porous implants by immersion in simulated physiologic solution. In addition, various Ca-P phases, such as octacalcium phosphate (OCP) or bone-like carbonated apatite (BCA), which are stable only at low temperatures, can be deposited. In this pilot study, experiments were designed with a twofold-purpose: (1) to investigate the osteoinduction of OCP-coated and noncoated porous tantalum cylinders and of dense titanium alloy cylinders (5 mm in diameter and 10 mm in length) in the back muscle of goats at 12 and 24 weeks (n = 4); and (2) to compare the osteogenic potentials of BCA-coated, OCP-coated, and bare porous tantalum cylinders in a gap of 1 mm created in the femoral condyle of a goat at 12 weeks (n = 2). In the goat muscle, after 12 weeks the OCP-coated porous cylinder had induced ectopic bone as well as bone within the cavity of the OCP-coated dense titanium cylinder. In the femoral condyle, bone did not fill the gap in any of the porous implants. In contrast with the two other groups, OCP-coated porous cylinders exhibited bone formation in the center of the implant. The nature of the Ca-P coating, via its microstructure, its dissolution rate, and its specific interactions with body fluids, may influence the osteogenecity of the Ca-P biomaterial.
authors.affiliation: IsoTis NV, Prof Bronkhorstlaan 10, PO Box 98, 3720 AB Bilthoven, The Netherlands.
authors.forename: Florence
authors.initials: F
authors.lastname: Barrère
authors.forename: Chantal M
authors.initials: CM
authors.lastname: van der Valk
authors.forename: Remco A J
authors.initials: RA
authors.lastname: Dalmeijer
authors.forename: Gert
authors.initials: G
authors.lastname: Meijer
authors.forename: Clemens A
authors.initials: CA
authors.lastname: van Blitterswijk
authors.forename: Klaas
authors.initials: K
authors.lastname: de Groot
authors.forename: Pierre
authors.initials: P
authors.lastname: Layrolle
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D002130:Calcium Phosphates; D005269:Femur / Q000503:physiopathology; D006041:Goats; D008855:Microscopy, Electron, Scanning; D019736:Prostheses and Implants; D013635:Tantalum
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; C022045:octacalcium phosphate; D013635:Tantalum