title: Osteogenesis-inducing calcium phosphate nanoparticle precursors applied to titanium surfaces.
abstract: This study investigated the effects of the morphology and physicochemical properties of calcium phosphate (CaP) nanoparticles on osteogenesis. Two types of CaP nanoparticles were compared, namely amorphous calcium phosphate (ACP) nano-spheres (diameter: 9-13 nm) and poorly crystalline apatite (PCA) nano-needles (30-50 nm × 2-4 nm) that closely resemble bone apatite. CaP particles were spin-coated onto titanium discs and implants; they were evaluated in cultured mouse calvarial osteoblasts, as well as after implantation in rabbit femurs. A significant dependence of CaP coatings was observed in osteoblast-related gene expression (Runx2, Col1a1 and Spp1). Specifically, the PCA group presented an up-regulation of the osteospecific genes, while the ACP group suppressed the Runx2 and Col1a1 expression when compared to blank titanium substrates. Both the ACP and PCA groups presented a more than three-fold increase of calcium deposition, as suggested by Alizarin red staining. The removal torque results implied a slight tendency in favour of the PCA group. Different forms of CaP nanostructures presented different biologic differences; the obtained information can be used to optimize surface coatings on biomaterials.
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
authors.forename: Wenxiao
authors.initials: W
authors.lastname: He
authors.forename: Martin
authors.initials: M
authors.lastname: Andersson
authors.forename: Pedro Paulo Chaves
authors.initials: PP
authors.lastname: de Souza
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: de Souza Costa
authors.forename: Eduardo Mariscal
authors.initials: EM
authors.lastname: Muñoz
authors.forename: Humberto Osvaldo
authors.initials: HO
authors.lastname: Schwartz-Filho
authors.forename: Mariko
authors.initials: M
authors.lastname: Hayashi
authors.forename: Amanda
authors.initials: A
authors.lastname: Hemdal
authors.forename: Axel
authors.initials: A
authors.lastname: Fredel
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
mesh_terms: D000818:Animals; D001031:Apatites / Q000737:chemistry; D018786:Bone Substitutes / Q000737:chemistry; D002130:Calcium Phosphates / Q000737:chemistry; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D015870:Gene Expression; D008422:Materials Testing; D051379:Mice; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010012:Osteogenesis; D010027:Osteotomy; D011817:Rabbits; D014025:Titanium
chemical_list: D001031:Apatites; D018786:Bone Substitutes; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; C020243:calcium phosphate; D014025:Titanium