title: Effects of a micro/nano rough strontium-loaded surface on osseointegration.
abstract: We developed a hierarchical hybrid micro/nanorough strontium-loaded Ti (MNT-Sr) surface fabricated through hydrofluoric acid etching followed by magnetron sputtering and evaluated the effects of this surface on osseointegration. Samples with a smooth Ti (ST) surface, micro Ti (MT) surface treated with hydrofluoric acid etching, and strontium-loaded nano Ti (NT-Sr) surface treated with SrTiO3 target deposited via magnetron sputtering technique were investigated in parallel for comparison. The results showed that MNT-Sr surfaces were prepared successfully and with high interface bonding strength. Moreover, slow Sr release could be detected when the MNT-Sr and NT-Sr samples were immersed in phosphate-buffered saline. In in vitro experiments, the MNT-Sr surface significantly improved the proliferation and differentiation of osteoblasts compared with the other three groups. Twelve weeks after the four different surface implants were inserted into the distal femurs of 40 rats, the bone-implant contact in the ST, MT, NT-Sr, and MNT-Sr groups were 39.70%±6.00%, 57.60%±7.79%, 46.10%±5.51%, and 70.38%±8.61%, respectively. In terms of the mineral apposition ratio, the MNT-Sr group increased by 129%, 58%, and 25% compared with the values of the ST, MT, and NT-Sr groups, respectively. Moreover, the maximal pullout force in the MNT-Sr group was 1.12-, 0.31-, and 0.69-fold higher than the values of the ST, MT, and NT-Sr groups, respectively. These results suggested that the MNT-Sr surface has a synergistic effect of hierarchical micro/nano-topography and strontium for enhanced osseointegration, and it may be a promising option for clinical use. Compared with the MT surface, the NT-Sr surface significantly improved the differentiation of osteoblasts in vitro. In the in vivo animal experiment, the MT surface significantly enhanced the bone-implant contact and maximal pullout force than the NT-Sr surface.
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, the Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Stomatology, the Second Hospital of Hebei Medical University, Shijiazhuang, People's Republic of China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Qi
authors.affiliation: Department of Stomatology, PLA 458 Hospital, Guangzhou, People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, the Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Niu
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Stomatology, the Second Hospital of Hebei Medical University, Shijiazhuang, People's Republic of China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, the Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, the Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Kaijin
authors.initials: K
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Oral and Maxillofacial Surgery, School of Stomatology, the Fourth Military Medical University, Xi'an, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Kong
mesh_terms: D000818:Animals; D000069343:Bone-Implant Interface / Q000502:physiology*; D005269:Femur / Q000187:drug effects*; D053758:Nanoparticles / Q000737:chemistry*; D016348:Osseointegration / Q000187:drug effects*; D010087:Oxides / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D013324:Strontium / Q000737:chemistry / Q000494:pharmacology; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology
chemical_list: D010087:Oxides; D014025:Titanium; C119252:strontium titanium oxide; D013324:Strontium
keywords: implant; micro/nanorough; surface modification