title: Where bone meets implant: the characterization of nano-osseointegration.
abstract: The recent application of electron tomography to the study of biomaterial interfaces with bone has brought about an awareness of nano-osseointegration and, to a further extent, demanded increasingly advanced characterization methodologies. In this study, nanoscale osseointegration has been studied via laser-modified titanium implants. The micro- and nano-structured implants were placed in the proximal tibia of New Zealand white rabbits for six months. High-resolution transmission electron microscopy (HRTEM), analytical microscopy, including energy dispersive X-ray spectroscopy (EDXS) and energy-filtered TEM (EFTEM), as well as electron tomography studies were used to investigate the degree of nano-osseointegration in two- and three-dimensions. HRTEM indicated the laser-modified surface encouraged the formation of crystalline hydroxyapatite in the immediate vicinity of the implant. Analytical studies suggested the presence of a functionally graded interface at the implant surface, characterized by the gradual intermixing of bone with oxide layer. Yet, the most compelling of techniques, which enabled straightforward visualization of nano-osseointegration, proved to be segmentation of electron tomographic reconstructions, where thresholding techniques identified bone penetrating into the nanoscale roughened surface features of laser-modified titanium. Combining high-resolution, analytical and three-dimensional electron microscopy techniques has proven to encourage identification and understanding of nano-osseointegration.
authors.affiliation: Department of Engineering Sciences, Uppsala University, Uppsala, Sweden. kathryn.grandfield@gmail.com
authors.forename: Kathryn
authors.initials: K
authors.lastname: Grandfield
authors.forename: Stefan
authors.initials: S
authors.lastname: Gustafsson
authors.forename: Anders
authors.initials: A
authors.lastname: Palmquist
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000494:pharmacology*; D017886:Durapatite / Q000378:metabolism*; D055032:Electron Microscope Tomography; D005260:Female; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D016348:Osseointegration / Q000187:drug effects*; D011817:Rabbits; D013052:Spectrometry, X-Ray Emission; D013977:Tibia / Q000378:metabolism* / Q000648:ultrastructure; D013978:Tibial Fractures / Q000401:mortality / Q000473:pathology / Q000628:therapy
chemical_list: D018786:Bone Substitutes; D017886:Durapatite