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. 2017 Feb 25;10(3):229.
doi: 10.3390/ma10030229.

Textural, Structural and Biological Evaluation of Hydroxyapatite Doped with Zinc at Low Concentrations

Daniela Predoi  1 , Simona Liliana Iconaru  2 , Aurélien Deniaud  3   4   5 , Mireille Chevallet  6   7   8 , Isabelle Michaud-Soret  9   10   11 , Nicolas Buton  12 , Alina Mihaela Prodan  13   14
Affiliations

Textural, Structural and Biological Evaluation of Hydroxyapatite Doped with Zinc at Low Concentrations

Daniela Predoi et al. Materials (Basel). .

Abstract

The present work was focused on the synthesis and characterization of hydroxyapatite doped with low concentrations of zinc (Zn:HAp) (0.01 < xZn < 0.05). The incorporation of low concentrations of Zn2+ ions in the hydroxyapatite (HAp) structure was achieved by co-precipitation method. The physico-chemical properties of the samples were characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), zeta-potential, and DLS and N₂-BET measurements. The results obtained by XRD and FTIR studies demonstrated that doping hydroxyapatite with low concentrations of zinc leads to the formation of a hexagonal structure with lattice parameters characteristic to hydroxyapatite. The XRD studies have also shown that the crystallite size and lattice parameters of the unit cell depend on the substitutions of Ca2+ with Zn2+ in the apatitic structure. Moreover, the FTIR analysis revealed that the water content increases with the increase of zinc concentration. Furthermore, the Energy Dispersive X-ray Analysis (EDAX) and XPS analyses showed that the elements Ca, P, O, and Zn were found in all the Zn:HAp samples suggesting that the synthesized materials were zinc doped hydroxyapatite, Ca10-xZnx(PO₄)₆(OH), with 0.01 ≤ xZn ≤ 0.05. Antimicrobial assays on Staphylococcus aureus and Escherichia coli bacterial strains and HepG2 cell viability assay were carried out.

Keywords: Escherichia coli; HepG2 cell viability; Staphylococcus aureus; hydroxyapatite; zinc.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
The XRD (X-ray diffraction) patterns of HAp and Zn:HAp, Ca10−xZnx(PO4)6(OH)2 synthesized samples with 0 ≤ xZn ≤ 0.05.
Figure 2
Figure 2
Fourier transform infrared spectroscopy (FTIR) spectra of Zn:HAp, samples with 0 ≤ xZn ≤ 0.05 from 400 to 1400 cm−1 (A) and from 1600 to 4000 cm−1 (B).
Figure 3
Figure 3
XPS general spectrum of Zn:Hap, Ca10−xZnx(PO4)6(OH)2 samples synthesized with 0.01 ≤ xZn ≤ 0.05 (A); and narrow scan spectra of Zn element (B).
Figure 4
Figure 4
Scanning electron microscopy (SEM) images (A); and the EDAX analysis (B) of Zn:HAp, samples with 0.01 ≤ xZn ≤ 0.05.
Figure 5
Figure 5
Colloidal characteristics of the Zn:Hap, Ca10−xZnx(PO4)6(OH)2 samples synthesized with 0.01 ≤ xZn ≤ 0.05: (A) zeta-potential distribution curves; and (B) hydrodynamic size distribution curves images.
Figure 6
Figure 6
Textural characteristics of the Zn:HAp, Ca10−xZnx(PO4)6(OH)2 samples synthesized with 0.01 ≤ xZn ≤ 0.05 using N2 adsorption–desorption isotherms and the pore size distribution curves.
Figure 7
Figure 7
Cell viability assays: (A) S. aureus cell growth in LB at 30 °C for 12 h in the presence of Zn:HAp with xZn = 0.01, xZn = 0.03 or xZn = 0.05 at concentrations between 1.95 and 1000 µg/mL; (B) E. coli cell growth in LB at 30 °C for 12 h in the presence of Zn:HAp with xZn = 0.01, xZn = 0.03 or xZn = 0.05 at concentrations between 1.95 and 1000 µg/mL; and (C) HepG2 viability after a 24 h incubation with Zn:HAp with xZn = 0.01, xZn = 0.03 or xZn = 0.05 at concentrations between 62.5 and 500 µg/mL. Error bars are calculated from at least 3 independent experiments.
Figure 8
Figure 8
Inverted phase contrast microscopy of HepG2 cells cultivated in the presence of Zn:HAp with xZn = 0.01, xZn = 0.03 and xZn = 0.05 at three different concentrations (62.5, 125 and 500 µg/mL) compared to control.
See this image and copyright information in PMC

References

    1. Tang Y., Chappell H.F., Dove M.T., Reeder R.J., Lee Y.J. Zinc incorporation into hydroxylapatite. Biomaterials. 2009;30:2864–2872. doi: 10.1016/j.biomaterials.2009.01.043. - DOI - PubMed
    1. Predoi D., Popa C.L., Predoi M.V. Ultrasound studies on magnetic fluids based on maghemite nanoparticles. Polym. Eng. Sci. 2017 doi: 10.1002/pen.24501. - DOI
    1. Glimcher M.J. Bone: Nature of the calcium phosphate crystals and cellular, structural, and physical chemical mechanisms in their formation. In: Sahai N., Schoonen M.A.A., editors. Medical Mineralogy and Geochemistry. Reviews in Mineralogy and Geochemistry. Volume 64. Mineralogical Society of America; Washington, DC, USA: 2006. pp. 223–282.
    1. Hing K.A., Wilson L.F., Buckland T. Comparative performance of three ceramic bone graft substitutes. Spine J. 2007;7:475–490. doi: 10.1016/j.spinee.2006.07.017. - DOI - PubMed
    1. Jallot E., Nedelec J.M., Grimault A.S., Chassot E., Grandjean-Laquerriere A., Laquerriere P., Laurent-Maquin D. STEM and EDXS characterisation of physico-chemical reactions at the periphery of sol–gel derived Zn-substituted hydroxyapatites during interactions with biological fluids. Colloid Surf. B. 2005;42:205–210. doi: 10.1016/j.colsurfb.2005.03.001. - DOI - PMC - PubMed

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