In vitro toxicity of Fe_mO_n, Fe_mO_n-SiO₂ composite, and SiO₂-Fe_mO_n core-shell magnetic nanoparticles

Figures & data

Figure 1 Schematic depiction of IONP synthesis.

Notes: (A) Uncoated IONPs; (B) Fe_mO_n-SiO₂ composite IONPs; (C) Silica-iron oxide core-shell structured IONPs.

Abbreviations: IONPs, magnetic iron oxide nanoparticles; RT, room temperature; TEOS, tetraethyl orthosilicate.

Figure 2 Characteristics of IONPs.

Notes: (A) TEM image of bare IONPs. (B) TEM image of Fe_mO_n-SiO₂ composite IONPs. (C) TEM image of SiO₂-Fe_mO_n core-shell IONPs. (D) and (E) Atomic force microscopy image of Fe_mO_n-SiO₂ composite and SiO₂-Fe_mO_n core-shell IONPs, respectively. (F) Hydrodynamic diameters of IONPs as measured by dynamic light scattering. (G) Room temperature mass magnetization curves for IONPs. (H) Fourier transform infrared spectra of IONPs.

Abbreviations: IONPs, magnetic iron oxide nanoparticles; TEM, transmission electron microscopy.

Table 1 The number of binucleated cells per field of view 48 h after incubation of HUVECs with 0.7 and 7.0 μg of uncoated IONPs, Fe_mO_n-SiO₂ composite, and SiO₂-Fe_mO_n core-shell IONPs

	0.7 µg (1.0 μL)	7.0 µg (10.0 µL)
Bare IONPs	2.8±1.16*	3.2±0.74
FemOn-SiO2 composite IONPs	0.8±0.49	3.0±0.63**
SiO2-FemOn core-shell IONPs	1.6±0.75	4.0±0.62**

Notes: Data are mean ± standard deviation.

* P<0.05 vs Fe_mO_n-SiO₂ composite and SiO₂-Fe_mO_n core-shell IONPs;

** P<0.05 vs the dose of 0.7 μg.

Abbreviations: HUVECs, human umbilical vein endothelial cells; IONPs, magnetic iron oxide nanoparticles.

Figure 3 Bright-field microscopy of human umbilical vein endothelial cells with 50× magnification 48 h after incubating with IONPs at three different doses; 0.7, 7.0, and 70.0 μg.

Notes: The images are representative of at least three independent experiments. (A–C) controls; (D–F) bare IONPs; (G–I) Fe_mO_n-SiO₂ composite IONPs; and (J–L) SiO₂-Fe_mO_n core-shell IONPs.

Abbreviation: IONPs, magnetic iron oxide nanoparticles.

Figure 4 Morphology of human umbilical vein endothelial cells 48 h after incubation with different doses of IONPs according to forward and side scattering profiles obtained with flow cytometry analysis.

Notes: (A–C) Controls; (D–F) Bare IONPs; (G–I) Fe_mO_n-SiO₂ composite IONPs; and (J–L) SiO₂-Fe_mO_n core-shell IONPs.

Abbreviation: IONPs, magnetic iron oxide nanoparticles.

Figure 5 In vitro cytotoxicity of IONPs.

Notes: (A) Percentage of annexin V-positive HUVECs as determined with annexin V-phycoerythrin apoptosis detection kit 48 h after incubation with three different doses of IONPs. *P<0.05 vs vehicle, ^&P<0.05 vs respective value at a dose of 0.7 μg; ^#P<0.01 vs vehicle; ^§P<0.05 vs respective value at a dose of 0.7 μg; (B) 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assay after 48 h of treatment with three different doses of IONPs. *P<0.05 vs vehicle; **P<0.05 vs respective value at a dose of 7.0 μg; ^$P<0.01 vs vehicle; ^@P<0.05 vs respective value at a dose of 7.0 μg. Data are expressed as means ± standard deviation.

Abbreviation: IONPs, magnetic iron oxide nanoparticles.