title: Discerning the role of topography and ion exchange in cell response of bioactive tissue engineering scaffolds.
abstract: Surface topography is known to have an influence on osteoblast activity. However, in the case of bioactive materials, topographical changes can affect also ion exchange properties. This makes the problem more complex, since it is often difficult to separate the strictly topographical effects from the effects of ionic fluctuations in the medium. The scope of this paper is to analyze the simultaneous effect of topography and topography-mediated ion exchange on the initial cellular behavior of osteoblastic-like cells cultured on bioactive tissue engineering substrates. Two apatitic substrates with identical chemical composition but different micro/nanostructural features were obtained by low-temperature setting of a calcium phosphate cement. MG63 osteoblastic-like cells were cultured either in direct contact with the substrates or with their extracts. A strong and permanent decrease of calcium concentration in the culture medium, dependent on substrate topography, was detected. A major effect of the substrate microstructure on cell proliferation was observed, explained in part by the topography-mediated ion exchange, but not specifically by the ionic Ca(2+) fluctuations. Cell differentiation was strongly enhanced when cells were cultured on the finer substrate. This effect was not explained by the chemical modification of the medium, but rather suggested a strictly topographical effect.
authors.affiliation: Biomaterials, Biomechanics, and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia, Barcelona, Spain.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Engel
authors.forename: Sergio
authors.initials: S
authors.lastname: Del Valle
authors.forename: Conrado
authors.initials: C
authors.lastname: Aparicio
authors.forename: George
authors.initials: G
authors.lastname: Altankov
authors.forename: Luis
authors.initials: L
authors.lastname: Asin
authors.forename: Josep A
authors.initials: JA
authors.lastname: Planell
authors.forename: Maria-Pau
authors.initials: MP
authors.lastname: Ginebra
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D001843:Bone Cements / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002130:Calcium Phosphates / Q000494:pharmacology; D002448:Cell Adhesion / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D048430:Cell Shape / Q000187:drug effects; D002478:Cells, Cultured; D003470:Culture Media; D017886:Durapatite / Q000494:pharmacology; D006801:Humans; D007368:Interferometry; D007474:Ion Exchange; D008422:Materials Testing; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000648:ultrastructure; D010758:Phosphorus / Q000378:metabolism; D011208:Powders; D023822:Tissue Engineering; D054457:Tissue Scaffolds
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; D003470:Culture Media; D011208:Powders; D010758:Phosphorus; D017886:Durapatite; C020243:calcium phosphate; D000469:Alkaline Phosphatase; D002118:Calcium