Preparation and characterization of hydroxyapatite from <i>A</i><i>chatina achatina</i> snail shells: effect of carbonate substitution and trace elements on defluoridation of water

Asimeng, Bernard Owusu; Fianko, Joseph Richmond; Kaufmann, Elsie Effah; Tiburu, Elvis K.; Hayford, Claude Fiifi; Anani, Prince Atsu; Dzikunu, Obed Korshie

doi:10.1080/21870764.2018.1488570

Cited by 29 publications

(21 citation statements)

References 32 publications

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“…However, small intensity reflections indicated the presence of calcite at 52.9 o and 64 o, implying incomplete conversion of Ca to HAp. This is similar to a pattern that was reported in the preparation of HAp from snail (Achatina achatina) shells [25]. Referring to the reflection of nano TiO 2 , it can be seen that there was no significant difference detected in the HAp-nTiO 2 reflection with respect to the HAp.…”

Section: Resultssupporting

confidence: 89%

Functionalization of hydroxyapatite derived from cockle (Anadara granosa) shells into hydroxyapatite–nano TiO2 for photocatalytic degradation of methyl violet

Fatimah

Fahrani

Harmawantika

et al. 2019

Sustain Environ Res

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Photocatalyst of hydroxyapatite-nano TiO 2 (HAp-nTiO 2) was prepared from phosphatation of calcined cockle (Anadara granosa) shells followed by dispersion of nano TiO 2 powder into HAp precipitate and calcination at 400°C for 2 h. The prepared material was characterized using X-ray diffraction, scanning electron microscope-energy dispersive X-ray spectrophotometry, gas sorption analysis, and UV-Vis diffuse reflectance spectrophotometry. The photocatalytic activity of the material was evaluated for methyl violet degradation over photocatalysis and photooxidation mechanism. The results showed that the homogeneous dispersion of TiO 2 in the HAp-nTiO 2 composite was achieved, as seen in the X-ray diffraction analysis, diffuse reflectance UV-Vis, and gas sorption analyses. The physicochemical and photocatalytic character of the composite exhibited the positive role of HAp as TiO 2 support in enhancing the photocatalytic activity with a higher turnover number and reusability property than that of pure TiO 2. It was also noted that the HAp-nTiO 2 composite demonstrated rapid methyl violet degradation over photooxidation rather than by photocatalytic mechanism.

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Section: Resultssupporting

confidence: 89%

Functionalization of hydroxyapatite derived from cockle (Anadara granosa) shells into hydroxyapatite–nano TiO2 for photocatalytic degradation of methyl violet

Fatimah

Fahrani

Harmawantika

et al. 2019

Sustain Environ Res

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“…The carbonate peaks show a difference in the transmittance between HAp1 and HAp3. This variation is due to the prolonged stirring of the materials at 40 • C as reported in literature (24). The decomposition of the carbonate might have been the reason for the reduction of the crystallite size indicated in the XRD.…”

Section: Infrared (Ir) Spectroscopymentioning

confidence: 52%

“…AA shells were calcined at 800℃ using the method described by Asimeng et al (24). HAp materials (n=2) were prepared from 0.3 M of the calcined AA shell (CAAS) material, and 0.5 M APD solutions.…”

Section: Hap Preparationmentioning

confidence: 99%

Electrochemical Evaluation of Ion Substituted-Hydroxyapatite on HeLa Cells Plasma Membrane Potential

Asimeng¹,

Tiburu²,

Kuafmann³

et al. 2018

Preprint

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This study reports the electrochemical activities of a novel ion substituted-Hydroxyapatite material in contact with HeLa cells. The work was performed to evaluate the inhibitory effects of various concentrations of the material on the ion transfer mechanisms in HeLa cells. The materials (n=2: HAp1 and HAp3) were prepared at different stirring times from Achatina achatina snail shells and phosphate-containing solution. The structure of the materials and the trace elements concentration were evaluated using x-ray diffractometry and infrared spectrometry as well as atomic absorption spectroscopy. Electrochemical studies conducted on the cells, after 30 min of exposure to the materials, demonstrated differential responses as elucidated by cyclic voltammetry. The voltammograms revealed HAp1 to be non-redox whereas HAp3 was redox active. Minimal concentrations of HAp1 showed high anodic peak current when compared to the HeLa cells alone, indicating a hyperpolarization of the cells. The peak current gradually reduced as the concentration of HAp1 was increased, and then a sudden rise suggesting inhibition of the cell action potential. HAp3 showed a wavy pattern of the anodic peak current when the material concentration was varied. Peak currents of 0.92 and 0.57 nA were recorded for HAp1 and HAp3, respectively at the highest concentration of 5 µL. The results suggest that different inhibitory mechanisms are at play on the voltage-gated ion channels of the cells, indicating the possibility of using the materials to achieve different cancer proliferation inhibition.

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“…The dried shells were crushed into powder using a mortar and pestle. The powder was calcined at 850 ºC for 2 h to convert the powder from aragonite to calcite [17]. Aragonite and calcite are the two main polymorphs of calcium carbonate (CaCO 3 ).…”

Section: Methodsmentioning

confidence: 99%

Influence of preferred orientation on the bioactivity of hydroxyapatite: a potential tooth repair and implant surface coating material

et al. 2020

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Bioactive hydroxyapatite (HAp) material was synthesized using a simple wet chemical precipitation and heat-treatment method from snail (Achatina achatina) shells and a phosphate-containing solution. According to X-ray diffraction patterns obtained, the heat-treatment caused a crystallographic preferred orientation along the HAp c-axis and thus, affected the material mineralization and bioactivity modeled in vitro using simulated body fluid (SBF) for 7 and 21 days. After 21 days of immersion, calcium and phosphate mineral concentrations in SBF decreased by 66% and 83%, respectively. This corresponded to a transformation from a poor calcium amorphous apatite phase (calcium phosphate) to a resorbing crystalline calcium apatite indicated by scanning electron microscopy micrographs. The material crystallite size (~15 nm), lattice parameters, physicochemical properties, and morphological characteristics were all typical of the human enamel apatite and, therefore, could be considered ideal for use in tooth repairs and implant surface coatings.

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Preparation and characterization of hydroxyapatite from Achatina achatina snail shells: effect of carbonate substitution and trace elements on defluoridation of water

Cited by 29 publications

References 32 publications

Functionalization of hydroxyapatite derived from cockle (Anadara granosa) shells into hydroxyapatite–nano TiO2 for photocatalytic degradation of methyl violet

Functionalization of hydroxyapatite derived from cockle (Anadara granosa) shells into hydroxyapatite–nano TiO2 for photocatalytic degradation of methyl violet

Electrochemical Evaluation of Ion Substituted-Hydroxyapatite on HeLa Cells Plasma Membrane Potential

Influence of preferred orientation on the bioactivity of hydroxyapatite: a potential tooth repair and implant surface coating material

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