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

Daniela Predoi,Aurélien Deniaud,Isabelle Michaud-Soret,Alina Prodan,Nicolas Buton,Simona Iconaru,Mireille Chevallet

doi:10.3390/ma10030229

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.

Highlights

In the last decades, researchers worldwide have focused their attention on the development of new and improved biomaterials for different biomedical applications [1,2,3,4]
According to previous studies conducted by Miyaji et al [18], this behavior suggests that the crystallinity of the apatite significantly decreases with the increase of zinc concentration
The current study investigated the structural and biological properties of hydroxyapatite doped with low concentrations of zinc (0.01< xZn < 0.05)

Summary

Introduction

Researchers worldwide have focused their attention on the development of new and improved biomaterials for different biomedical applications [1,2,3,4]. One of the main concerns in the medical field is finding new ways to treat bone diseases such as osteoporosis. Due to the fact that in most cases the installation of osteoporosis does not exhibit any symptoms, one of the first indication of this disease being a fractured bone, physicians from all around the world are trying to create synthetic materials that can mimic the human hard tissue, and improve the quality of the host tissue. Considering that hydroxyapatite (HAp), having the chemical formula Ca10 (PO4 ) (OH) , is the main inorganic constituent of human bones, synthetic HAp is already used in bone graft surgeries [1,2,3,4]. Hydroxyapatite is a biomaterial used on a large scale due to its outstanding biocompatible and bioactive properties [5]

Objectives

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Results

Conclusion