Dissolution and mineralization behaviors of HA coatings

Zhang, Q

doi:10.1016/s0142-9612(03)00371-5

Cited by 145 publications

(86 citation statements)

References 22 publications

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“…Zhang [28] analyzed the dissolution behavior of the HA coatings immersed in SBF and concluded that the dissolution of phosphate ions is dominated by crystallinity, while the dissolution of calcium ions is controlled by grain refinement. It is evident from XRD results (Fig.…”

Section: 2mentioning

confidence: 99%

A tough graphene nanosheet/hydroxyapatite composite with improved in vitro biocompatibility

Zhang

Liu

Yue

et al. 2013

Carbon

240

182

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A B S T R A C TMechanical properties and in vitro biocompatibility of graphene/hydroxyapatite (HA) composite synthesized using spark plasma sintering (SPS) are reported in this study. Raman spectroscopy corroborated that graphene nanosheets (GNSs) survived the harsh processing conditions of the selected SPS processing parameters. A 1.0 wt.% GNS/HA composite exhibits $80% improvement in fracture toughness as compared to pure HA. GNS pull-out, grain bridging by GNS, crack bridging and crack deflection are the major toughening mechanisms that resist crack propagation. In vitro osteoblast growth tests illustrate that the added GNSs contribute to the improvement of both osteoblast adhesion and apatite mineralization. Therefore, the GNS/HA composite is expected to be a promising material for load-bearing orthopedic implants.Ó 2013 Elsevier Ltd. All rights reserved. IntroductionGraphene, a monolayer of sp 2 -hybridized carbon atoms arranged in a two-dimensional lattice, has drawn much attention in the composite field as reinforcement for structural composites due to its combination of excellent mechanical properties (e.g., tensile strength 130 GPa and Young's modulus 0.5-1 TPa) and very high specific surface area (up to 2630 m 2 g À1 ) [1][2][3]. In particular, the high specific surface area of graphene, inherent to its two-dimensional lattice geometry, imparts strong interfacial bonding with the matrix phase and effective load transfer from the matrix to graphene [4]. Graphene nanosheets (GNSs) with a thickness of approximately 1-10 nm, also called as graphene nanoplatelets (GNPs) or graphene platelets (GPLs), are generally composed of a few graphene layers and display compatible properties similar to that of monolayer graphene. Furthermore, it is worth to note that GNSs are much easier to produce and handle. Very recently, GNSs have been widely employed as nanofillers to polymers [5,6], metals [7,8] and ceramics [9][10][11] to produce composites with tailored mechanical properties.Due to its chemical composition (Ca/P ratio of 1.67) and crystal structure that are similar to the apatite in human skeletal system, hydroxyapatite (HA), with excellent bioactivity and osteoconductivity, is suitable for osteoblast adhesion and proliferation, new bone growth and integration [12], and therefore is recognized as one of the most promising orthopedic biomaterials. However, the intrinsic brittleness of HA, i.e., low fracture toughness and low toughness-induced poor wear resistance, still restricts its clinical applications. Therefore, toughening of HA with a second phase such as alumina, yttria stabilized zirconia, titania and carbon nanotubes (CNTs) has been extensively explored to overcome the deficiencies of pure HA [13].Among HA based composites, much recent attention has been devoted to the CNT/HA composites.

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Section: 2mentioning

confidence: 99%

A tough graphene nanosheet/hydroxyapatite composite with improved in vitro biocompatibility

Zhang

Liu

Yue

et al. 2013

Carbon

240

182

View full text Add to dashboard Cite

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“…19,20 This metastable phase is then converted to hydroxyapatite (HAP) by dissolution and reprecipitation. 15,21 The transformation of ACP to HAP is inhibited by cobalt ions but unaffected by chromium. 22 Bodily fluids are supersaturated with respect to HAP.…”

Section: Introductionmentioning

confidence: 99%

The entrapment of corrosion products from CoCr implant alloys in the deposits of calcium phosphate: A comparison of serum, synovial fluid, albumin, EDTA, and water

Lewis

Kilburn

Heard

et al. 2006

Journal Orthopaedic Research

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Physical wear of orthopedic implants is inevitable. CoCr alloy samples, typically used in joint reconstruction, corrode rapidly after removal of the protective oxide layer. The behavior of CoCr pellets immersed in human serum, foetal bovine serum (FBS), synovial fluid, albumin in phosphate-buffered saline (PBS), EDTA in PBS, and water were studied using X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS). The difference in the corrosive nature of human serum, water, albumin in PBS and synovial fluid after 5 days of immersion was highlighted by the oxide layer, which was respectively 15, 3.5, 1.5, and 1.5 nm thick. The thickness of an additional calcium phosphate deposit from human serum and synovial fluid was 40 and 2 nm, respectively. Co and Cr ions migrated from the bulk metal surface and were trapped in this deposit by the phosphate anion. This may account for the composition of wear debris from CoCr orthopedic implants, which is known to consist predominantly of hydroxy-phosphate compounds. Known components of synovial fluid including proteoglycans, pyrophosphates, phospholipids, lubricin, and superficial zone protein (SZP), have been identified as possible causes for the lack of significant calcium phosphate deposition in this environment. Circulation of these compounds around the whole implant may inhibit calcium phosphate deposition. ß

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“…The of Ca/P ratio deviation from the stoichiometric value may be due to a surface layer with a composition differing from that of the bulk material. A difference in the surface and bulk stoichiometric ratios has [12,14,15]. The SEM micrographs of HAp samples showed a well defined platelet morphology.…”

Section: Resultsmentioning

confidence: 99%

Modification of the structure and composition of Ca₁₀(PO₄)₆(OH)₂ ceramic coatings by changing the deposition conditions in O₂ and Ar

Donkov

Zykova

Safonov

et al. 2014

J. Phys.: Conf. Ser.

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Dissolution and mineralization behaviors of HA coatings

Cited by 145 publications

References 22 publications

A tough graphene nanosheet/hydroxyapatite composite with improved in vitro biocompatibility

A tough graphene nanosheet/hydroxyapatite composite with improved in vitro biocompatibility

The entrapment of corrosion products from CoCr implant alloys in the deposits of calcium phosphate: A comparison of serum, synovial fluid, albumin, EDTA, and water

Modification of the structure and composition of Ca₁₀(PO₄)₆(OH)₂ ceramic coatings by changing the deposition conditions in O₂ and Ar

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Dissolution and mineralization behaviors of HA coatings

Cited by 145 publications

References 22 publications

A tough graphene nanosheet/hydroxyapatite composite with improved in vitro biocompatibility

A tough graphene nanosheet/hydroxyapatite composite with improved in vitro biocompatibility

The entrapment of corrosion products from CoCr implant alloys in the deposits of calcium phosphate: A comparison of serum, synovial fluid, albumin, EDTA, and water

Modification of the structure and composition of Ca10(PO4)6(OH)2 ceramic coatings by changing the deposition conditions in O2 and Ar

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Modification of the structure and composition of Ca₁₀(PO₄)₆(OH)₂ ceramic coatings by changing the deposition conditions in O₂ and Ar