title: Local release of magnesium from mesoporous TiO2 coatings stimulates the peri-implant expression of osteogenic markers and improves osteoconductivity in vivo.
abstract: Local release of Mg ions from titanium implant surfaces has been shown to enhance implant retention and integration. To clarify the biological events that lead to this positive outcome, threaded implants coated with mesoporous TiO2 thin films were loaded with Mg-ions and placed in the tibia of rabbits for 3weeks, after surface characterization. Non-loaded mesoporous coated implants were used as controls. Peri-implant gene expression of a set of osteogenic and inflammatory assays was quantified by means of real-time quantitative polymerase chain reaction. The expression of three osteogenic markers (OC, RUNX-2 and IGF-1) was significantly more pronounced in the test specimens, suggesting that the release of Mg ions directly at the implant sites may stimulate an osteogenic environment. Furthermore, bone healing around implants was evaluated on histological slides and by diffraction-enhanced imaging (DEI), using synchrotron radiation. The histological analysis demonstrated new bone formation around all implants, without negative responses, with a significant increase in the number of threads filled with new bone for test surfaces. DEI analysis attested the high mineral content of the newly formed bone. Improved surface osteoconductivity and increased expression of genes involved in the bone regeneration were found for magnesium-incorporation of mesoporous TiO2 coatings.
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, 205 06 Malmö, Sweden. Electronic address: silvia.galli@mah.se.
authors.forename: Silvia
authors.initials: S
authors.lastname: Galli
authors.affiliation: Oral Implant Center, Tokushima University Hospital, Tokushima, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Naito
authors.affiliation: Department of Chemical and Biological Engineering, Applied Surface Chemistry, Chalmers University of Technology, 412 96 Gothenburg, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Karlsson
authors.affiliation: Department of Chemical and Biological Engineering, Applied Surface Chemistry, Chalmers University of Technology, 412 96 Gothenburg, Sweden.
authors.forename: Wenxiao
authors.initials: W
authors.lastname: He
authors.affiliation: Division of Oral Medicine, Kyushu Dental University, Fukuoka, Japan.
authors.forename: Ikuya
authors.initials: I
authors.lastname: Miyamoto
authors.affiliation: Department of Clinical Dentistry, Center for Clinical Dental Research, University of Bergen, Norway.
authors.forename: Ying
authors.initials: Y
authors.lastname: Xue
authors.affiliation: Department of Chemical and Biological Engineering, Applied Surface Chemistry, Chalmers University of Technology, 412 96 Gothenburg, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Andersson
authors.affiliation: Department of Clinical Dentistry, Center for Clinical Dental Research, University of Bergen, Norway.
authors.forename: Kamal
authors.initials: K
authors.lastname: Mustafa
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, 205 06 Malmö, Sweden.
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, 205 06 Malmö, Sweden; Department of Applied Prosthodontics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D001861:Bone Regeneration / Q000187:drug effects / Q000502:physiology*; D001863:Bone Screws; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D004058:Diffusion; D019544:Equipment Failure Analysis; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008274:Magnesium / Q000008:administration & dosage* / Q000737:chemistry*; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D016062:Porosity; D011474:Prosthesis Design; D011817:Rabbits; D014025:Titanium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D036341:Intercellular Signaling Peptides and Proteins; C009495:titanium dioxide; D014025:Titanium; D008274:Magnesium
keywords: Diffraction-enhanced imaging; Gene expression; Local drug delivery osseointegration; Magnesium; Nanotopography