Fe³⁺/⁻ dual doped nano hydroxyapatite: A novel material for biomedical applications

Abstract

Abstract Dual ions substituted hydroxyapatite (HA) received attention from scientists and researchers in the biomedical field owing to their excellent biological properties. This paper presents a novel biomaterial, which holds potential for bone tissue applications. Herein, we have successfully incorporated ferric (Fe 3+ )/selenate ( ) ions into the HA structure (Ca 10‐ x ‐ y Fe y (PO 4 ) 6‐ x (SeO 4 ) x (OH) 2‐ x ‐ y O y ) (Fe‐SeHA) through a microwave refluxing process. The Fe‐SeHA materials were characterized by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FESEM). XRD and FTIR analyses revealed that Fe‐SeHA samples were phase pure at 900°C. FESEM images showed that formation of rod‐like shaped particles was inhibited dramatically with increasing Fe 3+ amount. The Vickers hardness (HV) test showed that hardness values increased with increasing Fe 3+ concentrations. Optical spectra of Fe‐SeHA materials contained broadband over (200–600) nm. In vitro degradation and bioactivity tests were conducted in simulated body fluid (SBF). The incorporation of Fe 3+ / ions into the HA structure resulted in a remarkably higher degradation rate along with intense growth of apatite granules on the surface of the Fe‐SeHA discs with Ca/P ratio of 1.35–1.47. In vitro protein adsorption assay was conducted in fetal bovine serum (FBS) and it was observed that the adsorption of serum proteins on Fe‐SeHA samples significantly increased with increasing Fe 3+ concentration. In vitro cytotoxicity tests were performed with human fetal osteoblast (hFOB) cell line and the results demonstrated that hFOB cells attached and proliferated faster on the Fe‐SeHA materials compared to pure HA showing that Fe‐SeHA materials were cytocompatible. ALP activity and intracellular calcium of hFOB cells on 1Fe‐SeHA discs were statistically higher than pure HA, suggesting that presence of Fe 3+ ion supported osteogenic differentiation of hFOB cells. Our results suggest that 1Fe‐SeHA (0.2 M Fe 3+ /0.5 M co‐doped HA) material could be considered as a promising candidate material for orthopedic applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 340–352, 2018.