Biomaterial for Bone and Dental Implants: Synthesis of B-Type Carbonated Hydroxyapatite from Biogenic Source

There are several sources from which hydroxyapatite (HAp) can be obtained and may be broadly categorized as synthetic or biogenic. Elevated interest in recent times has pushed for the development of several procedures for extracting HAp from biogenic wastes due to their excellent composition and morphology resemblance to the human calcified tissue (B-type carbonated HAp). Notable biogenic sources reported for HAp extraction span bovine bones, fish scales, corals, eggshells, and snails among other calcium-rich sources. However, most of the synthetic methods are laborious and therefore result in high production costs. In this chapter, we discuss the synthesis of B-type carbonate substituted HAp from an untapped biogenic source, Achatina achatina shells, using a simple precipitation method and a controlled heat-treatment method. This unique treatment method affected the substitution resulting in different crystallographic parameters and revealed a novel material for bone implants and enamel applications

Characterization and Inhibitory Effects of Magnetic Iron Oxide Nanoparticles Synthesized from Plant Extracts on HeLa Cells

Magnetic Fe3O4 nanoparticles were synthesized from maize leaves and plantain peels extract mediators. Particles were characterized, and the inhibitory effects were studied on HeLa cells in vitro using cyclic voltammetry (CV). Voltammograms from the CV show that Fe3O4 NPs interaction with HeLa cells affected their electrochemical behavior. The nanoparticles formed with higher Fe3+/Fe2+ molar ratio (2.8 : 1) resulted in smaller crystallite sizes compared to those formed with lower Fe3+/Fe2+ molar ratio (1.4 : 1). The particles with the smallest crystallite size showed higher anodic peak currents, whereas the larger crystallite sizes resulted in lower anodic peak currents. The peak currents relate to cell inhibition and are confirmed by the half-maximum inhibitory concentration (IC50). The findings show that the particles have a different inhibitory mechanism on HeLa cells ion transfer and are promising to be further exploited for cancer treatment

Characterization and Inhibitory Effects of Magnetic Iron Oxide Nanoparticles Synthesized from Plant Extracts on HeLa Cells

Magnetic Fe3O4 nanoparticles were synthesized from maize leaves and plantain peels extract mediators. Particles were characterized, and the inhibitory effects were studied on HeLa cells in vitro using cyclic voltammetry (CV). Voltammograms from the CV show that Fe3O4 NPs interaction with HeLa cells affected their electrochemical behavior. The nanoparticles formed with higher Fe3+/Fe2+ molar ratio (2.8 : 1) resulted in smaller crystallite sizes compared to those formed with lower Fe3+/Fe2+ molar ratio (1.4 : 1). The particles with the smallest crystallite size showed higher anodic peak currents, whereas the larger crystallite sizes resulted in lower anodic peak currents. The peak currents relate to cell inhibition and are confirmed by the half-maximum inhibitory concentration (IC50). The findings show that the particles have a different inhibitory mechanism on HeLa cells ion transfer and are promising to be further exploited for cancer treatment.</jats:p

Multiphase Mixed Material Derived From Calcite and Diammonium Hydrogen Phosphate Coated With Tetraethyl Orthosilicate: A Potential Implant Coating Material

A multiphase mixed material (M-PMM) made from calcite and diammonium hydrogen phosphate was prepared using the wet chemical method. To improve its bioactivity, the M-PMM was coated with tetraethyl orthosilicate (TEOS) at varying mass percentages of 5% and 10% producing 5%_TEOS-M-PMM and 10%_TEOS-M-PMM, respectively. In vitro mineralization studies were conducted by immersing the uncoated M-PMM, 5%_TEOS-M-PMM, and 10%_TEOS-M-PMM in simulated body fluid (SBF) for days 7, 14, and 21. Characterization of the uncoated and coated M-PMM was performed using X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersion X-ray spectroscopy (EDS), X-ray fluorescence (XRF), and scanning electron microscopy (SEM). The uncoated M-PMM was confirmed to consist of multiple phases, including calcite, mixed type-AB carbonate hydroxyapatite, and hydroxyapatite monoclinic2 by XRD and FTIR. EDS also confirmed the presence of silicon at the surface of the coated M-PMM, whereas XRD showed a decrease in crystallinity and crystallite size. The crystallinity and crystallite size were 81% and 20.88 ± 5.12 nm for uncoated M-PMM, respectively. The coated M-PMM had values of 79% and 17.27 ± 9.06 nm and 78% and 19.83 ± 9.91 nm for 5%_TEOS-M-PMM and 10%_TEOS-M-PMM, respectively. The larger surface area of the coated M-PMM in the SBF gave a better resorption of calcium and phosphate minerals, which was confirmed by XRF. Apatite-like bundles in the uncoated M-PMM and coated M-PMM after immersion in SBF from day 7 to day 21 were revealed by SEM. However, additional cuboid structures were seen in the coated M-PMM, which enhanced its cell viability and will aid in better osteointegration with biological tissues

Mechanical and Structural Characterization of Pineapple Leaf Fiber

Evidence-based research had shown that elevated alkali treatment of pineapple leaf fiber (PALF) compromised the mechanical properties of the fiber. In this work, PALF was subjected to differential alkali concentrations: 1, 3, 6, and 9% wt/wt to study the influence on the mechanical and crystal properties of the fiber. The crystalline and mechanical properties of untreated and alkali-treated PALF samples were investigated by X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and tensile testing analysis. The XRD results indicated that crystal properties of the fibers were modified with 6% wt/wt alkali-treated PALF recording the highest crystallinity and crystallite size of 76% and 24 nm, respectively. The FTIR spectra suggested that all alkali-treated PALF samples underwent lignin and hemicellulose removal to varying degrees. An increase in the crystalline properties improved the mechanical properties of the PALF treated with alkali at 6% wt/wt, which has the highest tensile strength (1620 MPa). Although the elevated alkali treatment resulted in decreased mechanical properties of PALF, crystallinity generally increased. The findings revealed that the mechanical properties of PALF not only improve with increasing crystallinity and crystallite size, but are also dependent on the intermediate bond between adjacent cellulose chains.Applied Science, Faculty ofNon UBCChemical and Biological Engineering, Department ofReviewedFacult

Snail Based Carbonated-Hydroxyapatite Material as Adsorbents for Water Iron (II)

Carbonated hydroxyapatite (CHAp) adsorbent material was prepared from Achatina achatina snail shells and phosphate-containing solution using a wet chemical deposition method. The CHAp adsorbent material was investigated to adsorb aqua Fe(II) complex; [Fe(H₂O)₆]²⁺ from simulated iron contaminated water for potential iron remediation application. The CHAp was characterized before and after adsorption using infrared (IR) and Raman spectroscopy. The IR and the Raman data revealed that the carbonate functional groups of the CHAp adsorbent material through asymmetric orientation in water bonded strongly to the aqua Fe(II) complex adsorbate. The adsorption behaviour of the adsorbate onto the CHAp adsorbent correlated well to pseudo-second-order kinetics model, non-linear Langmuir and Freundlich model at room temperature of a concentration (20–100 mg L -¹) and contact time of 180 min. The Langmuir model estimated the maximum adsorption capacity to be 45.87 mg g -¹ whereas Freundlich model indicated an S-type isotherm curvature which supported the spectroscopy revelation.Applied Science, Faculty ofNon UBCChemical and Biological Engineering, Department ofReviewedFacult

Snail Based Carbonated-Hydroxyapatite Material as Adsorbents for Water Iron (II)

Carbonated hydroxyapatite (CHAp) adsorbent material was prepared from Achatina achatina snail shells and phosphate-containing solution using a wet chemical deposition method. The CHAp adsorbent material was investigated to adsorb aqua Fe(II) complex; [Fe(H2O)6]2+ from simulated iron contaminated water for potential iron remediation application. The CHAp was characterized before and after adsorption using infrared (IR) and Raman spectroscopy. The IR and the Raman data revealed that the carbonate functional groups of the CHAp adsorbent material through asymmetric orientation in water bonded strongly to the aqua Fe(II) complex adsorbate. The adsorption behaviour of the adsorbate onto the CHAp adsorbent correlated well to pseudo-second-order kinetics model, non-linear Langmuir and Freundlich model at room temperature of a concentration (20–100 mg L−1) and contact time of 180 min. The Langmuir model estimated the maximum adsorption capacity to be 45.87 mg g−1 whereas Freundlich model indicated an S-type isotherm curvature which supported the spectroscopy revelation.</jats:p

Electrochemical evaluation of ion substituted-hydroxyapatite on HeLa cells plasma membrane potential

This study reports the electrochemical activities of a novel ion substituted-Hydroxyapatite (HAp) material in contact with HeLa cells. The work was performed to evaluate the inhibitory effects of various concentrations of HAp on 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 different 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 followed by 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 $$0.92 \pm 0.03$$ nA and $$0.57 \pm 0.01$$ 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