Journal ArticleDOI
Novel synthesis and characterization of an AB‐type carbonate‐substituted hydroxyapatite
Iain R. Gibson,William Bonfield +1 more
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TLDR
A novel synthesis route has been developed to produce a high-purity mixed AB-type carbonate-substituted hydroxyapatite (CHA) with a carbonate content that is comparable to the type and level observed in bone mineral.Abstract:
A novel synthesis route has been developed to produce a high-purity mixed AB-type carbonate-substituted hydroxyapatite (CHA) with a carbonate content that is comparable to the type and level observed in bone mineral. This method involves the aqueous precipitation in the presence of carbonate ions in solution of a calcium phosphate apatite with a Ca/P molar ratio greater than the stoichiometric value of 1.67 for hydroxyapatite (HA). The resulting calcium-rich carbonate-apatite is sintered/heat-treated in a carbon dioxide atmosphere to produce a single-phase, crystalline carbonate-substituted hydroxyapatite. In contrast to previous methods for producing B- or AB-type carbonate-substituted hydroxyapatites, no sodium or ammonium ions, which would be present in the reaction mixture from the sodium or ammonium carbonates commonly used as a source of carbonate ions, were present in the final product. The chemical and phase compositions of the carbonate-substituted hydroxyapatite was characterized by X-ray fluorescence and X-ray diffraction, respectively, and the level and nature of the carbonate substitution were studied using C-H-N analysis and Fourier transform infrared spectroscopy, respectively. The carbonate substitution improves the densification of hydroxyapatite and reduces the sintering temperature required to achieve near-full density by approximately 200 degrees C compared to stoichiometric HA. Initial studies have shown that these carbonate-substituted hydroxyapatites have improved mechanical and biologic properties compared to stoichiometric hydroxyapatite.read more
Citations
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Journal ArticleDOI
Synthesis methods for nanosized hydroxyapatite with diverse structures.
TL;DR: This article is focused on nanosized HAp, although recent articles on microsized particles, especially those assembled from nanoparticles and/or nanocrystals, have been reviewed for comparison.
Journal ArticleDOI
Nanosized hydroxyapatite and other calcium phosphates: chemistry of formation and application as drug and gene delivery agents.
Vuk Uskoković,Dragan Uskoković +1 more
TL;DR: Calcium phosphate nanoparticles as carriers of therapeutic agents that would enable a controlled drug release to treat a given bone infection and at the same be resorbed in the body so as to regenerate hard tissue lost to disease are emphasized as one of the potentially attractive smart materials for the modern medicine.
Journal ArticleDOI
Synthesis of Si, Mg substituted hydroxyapatites and their sintering behaviors
TL;DR: It is observed that ion substitutions by an amount higher than the above ratios for each hydroxyapatite lead to destabilization of original structures of the hydroxyAPatite and to the production of tricalcium phosphate and calcium phosphate silicate phases when the samples were sintered at 1100 degrees C or higher.
Journal ArticleDOI
Bone reconstruction: from bioceramics to tissue engineering.
TL;DR: The synthesis of a new generation of biomaterials that can specifically serve as tissue engineering scaffolds for drug and cell delivery is needed and nanotechnology can provide an alternative way of processing porous bioceramics with high mechanical strength and enhanced bioactivity and resorbability.
Journal ArticleDOI
Biomimetic Mg-substituted hydroxyapatite: from synthesis to in vivo behaviour
TL;DR: In vivo tests were carried out on New Zealand White rabbits using the granulate as filling for a femoral bone defect: osteoconductivity and resorption were found to be enhanced compared to commercial stoichiometric HA granulate, taken as control.
References
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Journal ArticleDOI
Bioceramics: From Concept to Clinic
TL;DR: The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues.
Journal Article
Bioceramics : from concept to clinic
TL;DR: The mechanisms of tissue bonding to bioactive ceramics are beginning to be understood, which can result in the molecular design of bioceramics for interfacial bonding with hard and soft tissues.
Journal ArticleDOI
Ca, P‐rich layer formed on high‐strength bioactive glass‐ceramic A‐W
Tadashi Kokubo,Setsuro Ito,Z. T. Huang,Takeshi Hayashi,Sumio Sakka,Toshiaki Kitsugi,Takao Yamamuro +6 more
TL;DR: It is concluded that the essential condition for glass and glass-ceramic to bond to bone is the formation of the surface apatite layer in the body environment but it is not essential to contain apatites within the material.
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Characterization of hydroxyapatite and carbonated apatite by photo acoustic FTIR spectroscopy
TL;DR: The structure of different commercial synthetic hydroxyapatite powders and a novel carbonated apatite have been studied with photo-acoustic (PAS) Fourier transform infrared (FTIR) spectroscopy to understand the interfacial relationship between a bioceramic implant and the adjacent bonet issue.