title: Titania and titania-silica coatings for titanium: comparison of ectopic bone formation within cell-seeded scaffolds.
abstract: The aim of this study was to compare titania (TiO(2))-coated, titania-silica (TiSi)-coated, and uncoated (cpTi) titanium fiber meshes as scaffolds for bone engineering. The scaffolds were loaded with bone marrow stromal cells and implanted subcutaneously in rats. Ectopic bone formation after 1, 4, and 12 weeks of implantation was evaluated using histology and histomorphometry. After 1 week of implantation, multiple patches of unorganized mineralizing tissue were seen in all implants. The amount of this bone-like tissue clearly increased from 1 to 4 weeks. Bone apposition occurred in direct contact with coated meshes, while a thin layer of unmineralized fibrous tissue was often observed surrounding cpTi mesh fibers. After 12 weeks, the structure of bone, with bone marrow-like tissue, was further matured and mesh fibers were embedded in lamellar bone. No statistical differences in the amount of mineralized bone were observed between scaffold types at any point of time. Only TiSi scaffolds showed further increase in bone area from 4 to 12 weeks (p < 0.01). A notable difference was that the sol-gel coatings resulted in enhanced initial bone contact and distribution of bone tissue, whereas uncoated implants showed bone formation mainly in the center of the scaffolds. In conclusion, TiO(2)-based sol-gel coatings may be used in tissue engineering to gain more uniform distribution of bone throughout titanium fiber mesh scaffolds.
authors.affiliation: Department of Prosthetic Dentistry and Biomaterials Science, Institute of Dentistry, University of Turku, Turku, Finland. ville.meretoja@utu.fi
authors.forename: Ville V
authors.initials: VV
authors.lastname: Meretoja
authors.forename: Teemu
authors.initials: T
authors.lastname: Tirri
authors.forename: Virpi
authors.initials: V
authors.lastname: Aäritalo
authors.forename: X Frank
authors.initials: XF
authors.lastname: Walboomers
authors.forename: John A
authors.initials: JA
authors.lastname: Jansen
authors.forename: Timo O
authors.initials: TO
authors.lastname: Närhi
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology* / Q000502:physiology; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D008297:Male; D008422:Materials Testing; D045164:Mesenchymal Stem Cell Transplantation / Q000379:methods*; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000502:physiology; D010012:Osteogenesis / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D012822:Silicon Dioxide / Q000737:chemistry*; D017154:Stromal Cells / Q000166:cytology / Q000502:physiology; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium