An intrinsically magnetic biomaterial with tunable magnetic properties

Abstract

Many magnetic materials lack intrinsic biocompatibility and require surface functionalization for in vivo applications. In this study, we fabricated an intrinsically biocompatible, biodegradable magnetic material through iron substitution into hydroxyapatite (FeHA) via ion-exchange. Controlling the oxidation state of iron in the ion exchange solution resulted in 'tunable' magnetic properties. Superparamagnetic behavior was observed in Fe 2+ HA and Fe 2+3+ HA and paramagnetism in Fe 3+ HA. FeHA powders were characterized using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), Fourier transform infra-red (FTIR) and X-ray photoelectron spectroscopy (XPS) with no detection of iron oxide phases. The as-synthesized HA and Fe 2+3+ HA samples were characterized in vitro using MC3T3-E1 cells. Cellular proliferation of Fe 2+3+ HA was found comparable to HA, while our cytotoxicity results from a lactate dehydrogenase assay showed Fe 2+3+ HA to be less toxic than pure HA, a widely used implantable biomaterial. Thus, these results collectively suggest that we have fabricated a magnetic biomaterial with intrinsic biocompatibility.

A Comparative Study of the Sintering Behavior of Pure and Manganese-Substituted Hydroxyapatite

“…HA with chemical impurities, such as carbonate, have been shown to degrade at temperatures as low as 800 °C [ 41 ]. The synthesis method used in this study was exposed to an ambient atmosphere which resulted in partial carbonation of the precipitated HA, as previously reported [ 42 ]. As the temperature increases from 900 to 1200 °C, the HA phase increases in crystallinity with temperature.…”

Synthesis, Characterization and Dye Removal Behavior of Core–Shell–Shell Fe3O4/Ag/Polyoxometalates Ternary Nanocomposites

“…The Fe 2p peaks are resolved into two peaks around 709.1 and 725.0 eV in Figure 2c, which are attributed to Fe 2p 3/2 and Fe 2p 1/2 respectively. The binding energy around 709 and 714 eV conforms to Fe 2+ 2p 3/2 and Fe 3+ 2p 3/2 [45,46]. It could be observed from Figure 2d that the distinct peaks at 935.4 eV and 955.3 eV can be attributed to Cu 2p 3/2 and Cu 2p 1/2 , respectively, showing an oxidation state of +2.…”

Inert atmosphere processing of hydroxyapatite in the presence of lithium iron phosphate

“…Furthermore, crystallinity was lowered [48]. In the case of Fe 3+ /Zn 2+ co-doping of HAp, decrease in both a and c parameters was observed [49], while Fe 3+ doping was also attributed to decrease in crystallinity of HAp [50]. The findings of decreased crystallite anisotropy and crystallinity, and increased microstructural strain of sample processed in the presence of LFP suggest that partial incorporation of Fe 2+ into HAp crystal lattice could occur.…”