title: In vivo evaluation of anodic TiO2 nanotubes: an experimental study in the pig.
abstract: Because of their ability to mimic the dimensions of constituent components of natural bone and the possibility to serve as a gene and drug-delivery carrier, nanotubes seem to be a promising coating for medical implants. Aim of this study was to investigate the effects of a TiO(2) nanotube structured surface on periimplant bone formation in vivo when compared with an untreated standard titanium surface. Twenty-five titanium implants covered with an ordered TiO(2) nanotube layer with an individual tube diameter of 30 nm and 25 commercially pure titanium (cp-Ti) implants were placed in the frontal skull of 25 domestic pigs. To evaluate the effects of the nanotube structured implants on the periimplant bone formation, bone-implant contact (BIC), and immunohistochemistry analysis were performed at day 3, 7, 14, 30, and 90. Evaluating immunohistochemistry, a significantly higher collagen type- I expression occurred at day 7 (p = 0.003), day 14 (p = 0.016), and day 30 (p = 0.044), for the nanostructured implants in comparison with the control group. It could be found that a nanotube structured implant surface with a diameter of 30 nm does influence bone formation and bone development by enhancing osteoblast function. SEM evaluation of the specimen surfaces revealed that the nanotube coatings do resist shearing forces that evoked by implant insertion. Because of their simple, low cost, flexible manufacturing and the possibility for the usage as drug or growth factor delivery system, nanotubes seem to be a promising method for future medical implant coatings.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany. cornelius.von-wilmowsky@uk-erlangen.de
authors.forename: Cornelius
authors.initials: C
authors.lastname: von Wilmowsky
authors.forename: Sebastian
authors.initials: S
authors.lastname: Bauer
authors.forename: Rainer
authors.initials: R
authors.lastname: Lutz
authors.forename: Mark
authors.initials: M
authors.lastname: Meisel
authors.forename: Friedrich Wilhelm
authors.initials: FW
authors.lastname: Neukam
authors.forename: Takeshi
authors.initials: T
authors.lastname: Toyoshima
authors.forename: Patrik
authors.initials: P
authors.lastname: Schmuki
authors.forename: Emeka
authors.initials: E
authors.lastname: Nkenke
authors.forename: Karl Andreas
authors.initials: KA
authors.lastname: Schlegel
mesh_terms: D000818:Animals; D001846:Bone Development / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004566:Electrodes; D006801:Humans; D020007:Implants, Experimental; D008422:Materials Testing; D043942:Nanotubes / Q000737:chemistry*; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology; D033081:Shear Strength; D013499:Surface Properties; D013552:Swine; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D015675:Osteocalcin; C009495:titanium dioxide; D014025:Titanium