title: Differential regulation of osteoblasts by substrate microstructural features.
abstract: Microtextured titanium implant surfaces enhance bone formation in vivo and osteoblast phenotypic expression in vitro, but the mechanisms are not understood. To determine the roles of specific microarchitectural features in modulating osteoblast behavior, we used Ti surfaces prepared by electrochemical micromachining as substrates for MG63 osteoblast-like cell culture. Cell response was compared to tissue culture plastic, a sand-blasted with large grit and acid-etched surface with defined mixed microtopography (SLA), polished Ti surfaces, and polished surfaces electrochemically machined through a photoresist pattern to produce cavities with 100, 30 and 10 microm diameters arranged so that the ratio of the microscopic-scale area of the cavities versus the microscopic-scale area of the flat region between the cavities was equal to 1 or 6. Microstructured disks were acid-etched, producing overall sub-micron-scale roughness (Ra=0.7 microm). Cell number, differentiation (alkaline phosphatase; osteocalcin) and local factor levels (TGF-beta1; PGE(2)) varied with microarchitecture. 100 microm cavities favored osteoblast attachment and growth, the sub-micron-scale etch enhanced differentiation and TGF-beta1 production, whereas PGE(2) depended on cavity dimensions but not the sub-micron-scale roughness.
authors.affiliation: Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland.
authors.forename: O
authors.initials: O
authors.lastname: Zinger
authors.forename: G
authors.initials: G
authors.lastname: Zhao
authors.forename: Z
authors.initials: Z
authors.lastname: Schwartz
authors.forename: J
authors.initials: J
authors.lastname: Simpson
authors.forename: M
authors.initials: M
authors.lastname: Wieland
authors.forename: D
authors.initials: D
authors.lastname: Landolt
authors.forename: Barbara
authors.initials: B
authors.lastname: Boyan
mesh_terms: D001672:Biocompatible Materials; D018786:Bone Substitutes; D002454:Cell Differentiation / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation; D004563:Electrochemistry / Q000379:methods; D006801:Humans; D008422:Materials Testing; D010006:Osteoblasts / Q000166:cytology* / Q000502:physiology; D010011:Osteocytes / Q000166:cytology* / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*; D014025:Titanium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D018786:Bone Substitutes; D014025:Titanium