title: Hydroxyapatite nanoparticles in poly-D,L-lactic acid coatings on porous titanium implants conducts bone formation.
abstract: It is well established in the field of biomaterials that hydroxyapatite (HA) may provide interesting osteoconductive properties. In this study, we investigated the osseointegrational effect of a 50/50 vol % composite of HA nanoparticles and poly-D,L-lactic acid (PDLLA) coated on model titanium bone implants in an in vivo animal model. The aim is to evaluate how the addition of HA to PDLLA may improve the bone formation and initial fixation of the implant. Two titanium implants coated with the PDLLA/HA composite and pure PDLLA, respectively, were implanted bilaterally in proximal part of humeri with a 2-mm peri-implant gap in 10 sheep. After 12 weeks, the remains of the coatings were present on 20.3 and 19.8% of PDLLA/HA composite- and PDLLA-coated implants, respectively. It was observed that newly formed bone (39.3%) and fibrous tissue (58.3%) had replaced the PDLLA/HA composite, whereas pure PDLLA was replaced almost completely by fibrous tissue (96.2%). Consequently, the PDLLA/HA composite-coated implants were better fixated as confirmed by push-out tests. Using quantification of peri-implant tissue and implant fixation as parameters, the present findings, therefore, clearly reveal that the addition of nanoparticulate HA to a PDLLA coating on titanium implants increases osseointegration.
authors: Orthopaedic Research Lab, Department of Orthopaedics, University Hospital of Aarhus, Aarhus C, Denmark.
authors: Thomas
authors: T
authors: Jensen
authors: Thomas
authors: T
authors: Jakobsen
authors: Jørgen
authors: J
authors: Baas
authors: Jens V
authors: JV
authors: Nygaard
authors: Alireza
authors: A
authors: Dolatshahi-Pirouz
authors: Mads B
authors: MB
authors: Hovgaard
authors: Morten
authors: M
authors: Foss
authors: Cody
authors: C
authors: Bünger
authors: Flemming
authors: F
authors: Besenbacher
authors: Kjeld
authors: K
authors: Søballe
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000033:anatomy & histology / Q000378:metabolism / Q000601:surgery; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000378:metabolism; D017886:Durapatite / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D020007:Implants, Experimental; D019344:Lactic Acid / Q000737:chemistry / Q000378:metabolism; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008854:Microscopy, Electron; D053758:Nanoparticles / Q000737:chemistry*; D010012:Osteogenesis / Q000502:physiology*; D011091:Polyesters; D011108:Polymers / Q000737:chemistry / Q000378:metabolism; D019736:Prostheses and Implants; D012756:Sheep; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide); D017886:Durapatite; D014025:Titanium