Synthesis and Characterization of Oleic Acid Coated Magnetic Nanoparticles for Hyperthermia Applications

Abstract

The present study focuses on obtaining highly stable iron oxide nanoparticles (IONs), stabilized by the coating of oleic acid (OA) for magnetic nano hyperthermia (MNH) applications. For this purpose, bare and different amounts of oleic acid (0.2%, 0.5% and 1.0%, v/v) coated IONs were prepared by co-precipitation method. Then, their structures, morphologies, magnetic properties and heating abilities were characterized by using suitable techniques. IONs+1.0%OA nanoparticles showed low agglomeration with high dispersion capacity. Moreover, 1.0% OA coating showed the highest heating ability with a temperature increase of (25.2 °C) compared to IONs+OA (0.2%, 16.4 °C; 0.5%, 19 °C), but similar to bare IONs (26.7 °C). The specific absorption rate (SAR) values of bare IONs and IONs+OA (0.2%, 0.5%, 1.0%, v/v) were found as 39.50, 34.81, 23.36 and 45.98 W/g, respectively. Our results showed that comparable hyperthermia effect of IONs+1.0%OA with bare IONs was attributable to their uniform dispersion performance along with higher SAR values. We concluded that the dispersion of hydrophobic IONs+OA in the aqueous medium is one of the critical requirements for increasing temperature in magnetic nano hyperthermia applications.

Coating of Magnetite Nanoparticles with Fucoidan to Enhance Magnetic Hyperthermia Efficiency

“…For instance, Giri et al [83], synthetized magnetite NP with similar sizes of 10-12 nm and obtained a lower ILP value (0.22 nHm 2 kg −1 ). Likewise, Senturk and co-workers produced magnetite NP with 8.3 ± 1.6 nm and an ILP of 0.23 was obtained [84]. This value is also higher than the value obtained by Shete et al [85] even for a higher magnetite NP size (21.8 ± 5 nm, 0.42 nHm 2 kg −1 ).…”

“…Concerning the post-synthesis coating with fucoidan (sample MF, mean size of 11.7 nm ± 3.1), the highest SLP value was obtained (156 W g −1 ) corresponding to an ILP value of 2.6 nHm 2 kg −1 . This thermal efficiency is superior in comparison with other reported coated magnetite particles (Table 4), including polyethylene glycol (PEG), [61,87] chitosan, [85] polycaprolactone (PCL), [88] dextran, [16] dimercaptosuccinic acid (DMSA) [89], silica, [90] poly-L-lysine, [91] oleic acid, [84] and folic acid [92]. Ghosh et al [87], through a co-precipitation method, obtained magnetite NP post-synthesis coated with polyethylene glycol (PEG) with a medium size of 10 nm and an ILP value of 0.1 nHm 2 kg −1 , which is much lower than the value resulted from MF.…”

“…Liu et al [90] also coated magnetite NP with silica targeting a combined thermotherapy and chemotherapy, achieving NP with 55 ± 10 nm and an ILP of 0.49 nHm 2 kg −1 . Poly-L-lysine 10 1.23 [91] Oleic acid 10 0.27 [84] Folic acid 21.1 2.52 [92] According to the literature, the application of coatings in situ is more complex, but provide greater stabilization and better magnetic properties [93]. However, the sample MF−IS exhibited a SLP value of 100.26 Wg −1 (ILP = 1.7 nHm 2 kg −1 ), lower than the obtained by post-synthesis coating.…”

Synthesis conditions and characterization of superparamagnetic iron oxide nanoparticles with oleic acid stabilizer

“…The previous studies showed that the concentrations of OA influenced the hydrodynamic size of SPIONs. [ 5 ] The addition of OA will form a protective monolayer that is linked to the surface of SPIONs and will form highly uniform and monodisperse SPIONs. [ 15 ] The larger hydrodynamic size could be the reason for increasing the polydispersity index.…”

“…However, this method produces highly agglomerated SPIONs resulting in less effectiveness in biomedical application. [ 5 6 ] Therefore, controlling the particle size and particle distributions of SPIONs is very crucial to avoid the SPION agglomerations and becomes a determinant of the synthesis process. SPIONs with particle sizes more than 100 nm can lose their magnetic properties easily because of oxidation and high chemical activity.…”