title: Covalently-linked hyaluronan promotes bone formation around Ti implants in a rabbit model.
abstract: The goal of this study was the in vivo evaluation of nanoporous titanium (Ti) implants bearing a covalently linked surface hyaluronan (HA) layer. Implant surface topography and surface chemistry were previously evaluated by scanning electron microscopy and X-ray photoelectron spectroscopy. Results showed that the surface modification process did not affect surface topography, yielding a homogeneously HA-coated nanotextured implant surface. In vivo evaluation of implants in both cortical and trabecular bone of rabbit femurs showed a significant improvement of both bone-to-implant contact and bone ingrowth at HA-bearing implant interfaces at 4 weeks. The improvement in osteointegration rate was particularly evident in the marrow-rich trabecular bone (bone-to-implant contact: control 22.5%; HA-coated 69.0%, p < 0.01). Mechanical testing (push-out test) and evaluation of interfacial bone microhardness confirmed a faster bone maturation around HA-coated implants (Bone Maturation Index: control 79.1%; HA-coated 90.6%, p < 0.05). Suggestions based on the biochemical role of HA are presented to account for the observed behavior.
authors.affiliation: Nobil Bio Ricerche, Str. S. Rocco 36, 14018 Villafranca d'Asti, Italy. mmorra@nobilbio.it
authors.forename: Marco
authors.initials: M
authors.lastname: Morra
authors.forename: Clara
authors.initials: C
authors.lastname: Cassinelli
authors.forename: Giovanna
authors.initials: G
authors.lastname: Cascardo
authors.forename: Milena
authors.initials: M
authors.lastname: Fini
authors.forename: Gianluca
authors.initials: G
authors.lastname: Giavaresi
authors.forename: Roberto
authors.initials: R
authors.lastname: Giardino
mesh_terms: D000818:Animals; D020099:Coated Materials, Biocompatible; D005269:Femur / Q000601:surgery; D006820:Hyaluronic Acid / Q000494:pharmacology*; D020007:Implants, Experimental; D008297:Male; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration / Q000187:drug effects*; D010012:Osteogenesis; D011817:Rabbits; D013057:Spectrum Analysis; D013499:Surface Properties; D014025:Titanium; D014965:X-Rays
chemical_list: D020099:Coated Materials, Biocompatible; D006820:Hyaluronic Acid; D014025:Titanium