Effect of particle size of metastable calcium phosphates on mechanical strength of a novel self-setting bioactive calcium phosphate cement

The use of bone graft materials is required for the treatment of bone defects damaged beyond the critical defect; therefore, injectable calcium phosphate cement (CPC) is actively used after surgery. The application of various polymers to improve injectability, mechanical strength, and biological function of injection-type CPC is encouraged. We previously developed a chitosan–PEG conjugate (CS/PEG) by a sulfur (VI) fluoride exchange reaction, and the resulting chitosan derivative showed high solubility at a neutral pH. We have demonstrated the CPC incorporated with a poly (ethylene glycol) (PEG)-grafted chitosan (CS/PEG) and developed CS/PEG CPC. The characterization of CS/PEG CPC was conducted using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The initial properties of CS/PEG CPCs, such as the pH, porosity, mechanical strength, zeta potential, and in vitro biocompatibility using the WST-1 assay, were also investigated. Moreover, osteocompatibility of CS/PEG CPCs was carried out via Alizarin Red S staining, immunocytochemistry, and Western blot analysis. CS/PEG CPC has enhanced mechanical strength compared to CPC, and the cohesion test also demonstrated in vivo stability. Furthermore, we determined whether CS/PEG CPC is a suitable candidate for promoting the osteogenic ability of Dental Pulp Stem Cells (DPSC). The elution of CS/PEG CPC entraps more calcium ion than CPC, as confirmed through the zeta potential test. Accordingly, the ion trapping effect of CS/PEG is considered to have played a role in promoting osteogenic differentiation of DPSCs. The results strongly suggested that CS/PEG could be used as suitable additives for improving osteogenic induction of bone substitute materials.

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Studies on Non-Quenched Calcium Phosphate Cement: Influences of Quenching and Milling on Setting Characteristic

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.330-332.39 ◽

2007 ◽

Vol 330-332 ◽

pp. 39-42 ◽

Cited By ~ 2

Author(s):

Xue Jiang Wang ◽

Yu Bao Li ◽

John A. Jansen ◽

Shi Hong Li ◽

Joop G.C. Wolke

Keyword(s):

Particle Size ◽

Calcium Phosphate ◽

Surface Area ◽

Calcium Phosphate Cement ◽

Tricalcium Phosphate ◽

Hydrated Layer ◽

Initial Setting

The aim of this study is to explore the effects of quenching and milling processing on setting property of calcium phosphate cement (CPC). For this purpose, non-quenched α-tricalcium phosphate (α-TCP) and quenched α-TCP were synthesized and their corresponding cement systems were prepared. The particle size of α-TCP powder was introduced as a variable. Then, setting properties of these CPC systems were estimated. By a comparison between non-quenched CPC and the quenched one, it is found that milling processing mainly influences the initial setting stage by decreasing reactant particle size whereas the quenching treatment affects the final setting stage by changing α-TCP content, which supports that CPC setting initially depends on the surface area of reactants and subsequently on the diffusion through the hydrated layer formed around the reactants.

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Preparation of Tetracalcium Phosphate and the Effect on the Properties of Calcium Phosphate Cement

Materials Science Forum ◽

10.4028/www.scientific.net/msf.610-613.1356 ◽

2009 ◽

Vol 610-613 ◽

pp. 1356-1359 ◽

Cited By ~ 3

Author(s):

Dan Kai ◽

Hong Song Fan ◽

Dong Xiao Li ◽

Xiang Dong Zhu ◽

Xing Dong Zhang

Keyword(s):

Particle Size ◽

Calcium Phosphate ◽

Calcium Phosphate Cement ◽

Preparation Method ◽

Precipitation Method ◽

Improve Performance ◽

Solid Reaction ◽

Tetracalcium Phosphate ◽

Fast Cooling ◽

Co Precipitation

In the present study, three types of tetracalcium phosphate (TTCP) were prepared by solid-solid reaction or co-precipitation method and by different cooling modes. The effect of TTCP on the performance of calcium phosphate cement (CPC) was investigated. The result showed that the characteristic of TTCP varied with preparation method and played an important role in CPC performance. A solid-solid reacted TTCP yielded smaller particle size and resulted in bad workability and mechanical strength of CPC. The fast cooling of sintering TTCP by liquid nitrogen could avoid the decomposition of TTCP and make pure TTCP. TTCP prepared by wet-precipitation could improve performance of CPC and was promising to optimization of CPC.

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Ultrasonic application and spray drying during amorphous calcium phosphate synthesis

Letters in Applied NanoBioScience ◽

10.33263/lianbs84.711714 ◽

2019 ◽

Vol 8 (4) ◽

pp. 711-714

Keyword(s):

Electron Microscopy ◽

Particle Size ◽

Calcium Phosphate ◽

Spray Drying ◽

Amorphous Calcium Phosphate ◽

Calcium Phosphates ◽

Calcium Content ◽

Synthesis Process ◽

Particle Sizes ◽

Ultrasound Application

Hydroxyapatite, amorphous calcium phosphates, calcium triphosphate and calcium octaphosphate are the main components present in bones and teeth. Calcium phosphates are easily synthesized, playing an important role in regenerative medicine, being able to be used as bone implants. There are different ways of synthesizing phosphates, the most commonly used being wet chemical method. The objective of this work was to study the influence of the use of ultrasound and spray drying on the synthesis of amorphous calcium phosphate. Two synthetic variants were studied. One without ultrasound application and the other with ultrasound application. The samples obtained were characterized by X-ray diffraction, FTIR spectroscopy and scanning electron microscopy. The particle size by electron microscopy and the calcium content by atomic absorption was determined. The results showed that when spray drying is applied, particle sizes of less than 261 nm are obtained in the samples synthesized without ultrasound application, being less than 59 nm in the samples synthesized with ultrasound application. The statistical analysis by ANOVA showed significant differences between the particle sizes of the samples synthesized without ultrasound application and the samples synthesized by applying ultrasound. In both cases the particles were spherical. The results obtained show that the application of ultrasound during the synthesis process decreases the particle size, increasing the surface area, which favors the spray drying process.

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Influence of particle size on hardening and handling of a premixed calcium phosphate cement

Journal of Materials Science Materials in Medicine ◽

10.1007/s10856-013-4855-z ◽

2013 ◽

Vol 24 (4) ◽

pp. 829-835 ◽

Cited By ~ 8

Author(s):

Jonas Åberg ◽

Johanna Engstrand ◽

Håkan Engqvist

Keyword(s):

Particle Size ◽

Calcium Phosphate ◽

Calcium Phosphate Cement

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Effect on Drying Conditions on Amorphous Calcium Phosphate

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.631.99 ◽

2014 ◽

Vol 631 ◽

pp. 99-103 ◽

Cited By ~ 4

Author(s):

Agnese Brangule ◽

Kārlis Gross

Keyword(s):

Particle Size ◽

Calcium Phosphate ◽

Amorphous Calcium Phosphate ◽

Intermediate Phase ◽

Calcium Phosphates ◽

Ftir Spectra ◽

The Body ◽

Drying Methods ◽

Dry Conditions ◽

Drying Conditions

Amorphous calcium phosphate (ACP) plays an important role in the body and can be used as an intermediate phase for forming calcium phosphates. All ACPs are thermodynamically unstable compounds, unless stored in dry conditions or at low temperature (-18oC), and spontaneously undergo transformation to crystalline calcium phosphates (CaP). This work will investigate the influence of drying on the stability of ACP. ACPs powders were prepared by wet synthesis; mixing solution made of Ca (NO3)2∙4H2O and 30% ammonia with (NH4)2HPO4 and (NH4)2CO3 solution at room temperature. The suspension was stirred, filtered and washed several times with deionized water containing ammonia. ACP samples were dried at different conditions and with different drying agents (DA). XRD and FTIR spectra showed poorly crystallinity powders after drying. Some FTIR spectra indicated residual organic compounds from drying. The Rietveld’s method and Schrrer’s relationship estimated the particle size (0.5 – 20 nm) of ACP. Thermogravimetry (TG) revealed that the moisture (7% – 25%) is released upon drying, and the drying agents have no significant effect on. The drying methods are ordered to show which the most effective for removing moisture. By changing the drying conditions, it is a possible to obtain poorly crystalline ACPs with different particle size and moisture content.

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Phosphorus retention by granulated apatite: assessing maximum retention capacity, kinetics and retention processes

Water Science & Technology ◽

10.2166/wst.2021.010 ◽

2021 ◽

Vol 83 (4) ◽

pp. 792-802

Author(s):

Laura Delgado-González ◽

Bruno Lartiges ◽

Mathieu Gautier ◽

Stéphane Troesch ◽

Pascal Molle

Keyword(s):

Particle Size ◽

Calcium Phosphate ◽

Particle Size Distribution ◽

Size Distribution ◽

Calcium Phosphates ◽

Rate Coefficients ◽

Phosphorus Retention ◽

Retention Capacity ◽

Phosphate Retention ◽

Granule Surface

Abstract Natural apatites have previously shown a great capacity for phosphate retention from wastewater. However, its fine particle size distribution may lead to a premature clogging of the filter. Accordingly, a granulated apatite product was developed and manufactured in order to control the particle size distribution of the media. Experiments were conducted on laboratory columns to assess their phosphorus retention capacity, to identify the processes involved in phosphorus retention and to evaluate their kinetic rates. The results showed phosphorus retention capacities of 10.5 and 12.4 g PO4-P·kg−1 and kinetic rate coefficients in the range of 0.63 and 0.23 h−1 involving lower values than those found for natural apatites in previous studies. Scanning Electron Microscopy images showed that apatite particles in the granules were embedded in the binder and were not readily accessible to act as seeds for calcium phosphate precipitation. The retention processes differ depending on the supersaturation of the solution with respect to calcium phosphate phases: at low calcium concentrations (69.8 ± 3.9 mg·L−1), hydroxyapatite precipitates fill up the porosity of the binder up to a depth of 100–300 μm from the granule surface; at higher calcium concentrations (112.7 ± 7.4 mg·L−1) precipitation occurs at the granule surface, forming successive layers of hydroxyapatite and carbonated calcium phosphates.

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