RF induction heating and in-vitro study of citrate functionalized Zr-substituted Fe3O4 nanoparticles with human lung adenocarcinoma (A549) cell

Highlights: • Citrate coated ZrxFe3-xO4 (0 ≤ x ≤ 0.3) nanoparticles were synthesized by polyol route. • Aggregation of MNPS (5-18 nm) was restricted due to coating (from FTIR and DLS). • Zeta potential confirms well dispersibility of ZrxFe3-xO4 based ferrofluids. • Suitable magnetic properties and heating ability for hyperthermia application. • 1.5 mg/mL of Zr0.3Fe2.7O4 nanoparticles after 48 h was compatible with A549 cells. We present a study on biocompatibility of citrate capped Zr_xFe_3-xO₄ based magnetic ferrofluids with human lung adenocarcinoma (A549) cell, evaluated by Sulforhodamine B assay. It was found to be ~86% at a concentration of 1.5 mg/mL after 48 h. We approached single step and cost effective polyol methodology to get a well dispersed and homogeneous aqueous suspension of citric acid coated Zr_xFe_3-xO₄, (0 ≤ x ≤ 0.3) MNP_S. We used citric acid which anchored over the surface of freshly prepared nanoparticles to provide stability for longer duration . The X-ray and electron diffractions suggested the formation of single phasic magnetite particles of size 5–18 nm. The aggregation of MNP_S was prevented by citric acid which was confirmed from Fourier-transform infrared spectroscopy spectra. The Zeta potential measurement inferred the well dispersion of nanoparticles at varying pH values (2−10). The Zr-substituted magnetite had relatively lower magnetization values than pure one. The optimum specific absorption rate (SAR) value at a field of 23 mT, 261 kHz was obtained to be 44 W/g for the sample x = 0.02 at a concentration of 10 mg/mL. In contrast, the intrinsic loss power (ILP) value was optimum (0.54 nHm²/kg) for Fe₃O₄ ferrofluid having a concentration of 5 mg/mL and at a field of 17 mT, 170 kHz. Nevertheless, the reported ferrofluids have displayed high heating capacity and suitable biocompatibility thus these could be used as promising materials for bioapplications including magnetic hyperthermia.