Influences of surface coatings and components of FePt nanoparticles on the suppression of glioma cell proliferation

Figures & data

Figure 1 TEM images of FePt NPs synthesized with different Fe/Pt molar ratios and surface coatings.

Notes: (A) Fe:Pt = 3:1, OA/OA; (B) Fe:Pt = 1:1, OA/OA; (C) Fe:Pt = 1:3, OA/OA; (D) Fe:Pt = 1:1, Cys; (E) Fe:Pt = 1:3, Cys.

Abbreviations: TEM, transmission electron microscopy; NPs, nanoparticles; OA/OA, oleic acid/oleylamine; Cys, cysteine.

Table 1 Compositions and sizes of FePt NPs synthesized at different Fe/Pt ratios and surface coatings

Sample	Precursors and molar ratio		Capping agent	Fe/Pt molar ratio	Composition (FexPt100−x)c	Diameter (nm)
						XRDd	TEMe
1a	Fe(acac)3/Pt(acac)2	3:1	OA/OA	60:40	Fe60Pt40-OA/OA	5.8	4.3 ± 0.5
2a		1:1		45:55	Fe45Pt55-OA/OA	7.7	7.1 ± 0.9
3a		1:3		27:73	Fe27Pt73-OA/OA	5.6	3.6 ± 0.4
4b	FeCl2/K2PtCl6	1:1	Cys	60:40	Fe60Pt40-Cys	4.6	3.1 ± 0.4
5b		1:3		24:76	Fe24Pt76-Cys	4.2	3.4 ± 0.3

Notes:

a Samples were synthesized using a polyol reduction route under refluxing temperature;

b samples were synthesized using NaBH4 as the reductant at room temperature;

c in context, FePt NPs with different surface coatings were denoted as Fe_xPt_100−x-OA/OA NPs or Fe_xPt_100−x-Cys NPs for convenience;

d sizes of NPs were calculated from XRD patterns according to the Debye–Scherrer formula;

e sizes of NPs were obtained from TEM images.

Abbreviations: NPs, nanoparticles; OA/OA, oleic acid/oleylamine; Cys, cysteine; XRD, X-ray diffraction; TEM, transmission electron microscopy.

Figure 2 XRD patterns of FePt NPs synthesized at different Fe/Pt molar ratios and with different surface coatings.

Notes: (A) Fe:Pt = 3:1, OA/OA; (B) Fe:Pt = 1:1, OA/OA; (C) Fe:Pt = 1:3, OA/OA; (D) Fe:Pt = 1:1, Cys; (E) Fe:Pt = 1:3, Cys.

Abbreviations: XRD, X-ray diffraction; NPs, nanoparticles; OA/OA, oleic acid/oleylamine; Cys, cysteine.

Figure 3 XPS spectra of Pt and Fe elements in the FePt NPs synthesized at different Fe/Pt molar ratios and with different surface coatings.

Notes: (A) Fe₆₀Pt₄₀-OA/OA; (B) Fe₄₅Pt₅₅-OA/OA; (C) Fe₂₇Pt₇₃-OA/OA; (D) Fe₆₀Pt₄₀-Cys; (E) Fe₂₄Pt₇₆-Cys.

Abbreviations: XPS, X-ray photon spectroscopy; OA/OA, oleic acid/oleylamine; Cys, cysteine.

Figure 4 FTIR spectra of FePt NPs synthesized with different surface coatings and components.

Notes: (A) Fe₆₀Pt₄₀-OA/OA; (B) Fe₄₅Pt₅₅-OA/OA; (C) Fe₂₇Pt₇₃-OA/OA; (D) oleylamine; (E) oleic acid; (F) Fe₆₀Pt₄₀-Cys; (G) Fe₂₄Pt₇₆-Cys; (H) cysteine.

Abbreviations: FTIR, Fourier transform infrared spectroscopy; NPs, nanoparticles; OA/OA, oleic acid/oleylamine.

Figure 5 Cell proliferation of human glioma U251 cells treated with FePt NPs with different components and surface coatings.

Notes: (A) Fe₆₀Pt₄₀-OA/OA; (B) Fe₄₅Pt₅₅-OA/OA; (C) Fe₂₇Pt₇₃-OA/OA; (D) Fe₆₀Pt₄₀-Cys; (E) Fe₂₄Pt₇₆-Cys.

Abbreviations: NPs, nanoparticles; OA/OA, oleic acid/oleylamine; Cys, cysteine.

Figure 6 Cell proliferation of human astrocytoma U87 cells treated with FePt NPs with different components and surface coatings.

Notes: (A) Fe₆₀Pt₄₀-OA/OA; (B) Fe₄₅Pt₅₅-OA/OA; (C) Fe₂₇Pt₇₃-OA/OA; (D) Fe₆₀Pt₄₀-Cys; (E) Fe₂₄Pt₇₆-Cys.

Abbreviations: NPs, nanoparticles; OA/OA, oleic acid/oleylamine; Cys, cysteine.

Figure 7 Cell proliferation of human neuroglioma H4 cells treated by FePt NPs with different components and surface coatings.

Notes: (A) Fe₆₀Pt₄₀-OA/OA; (B) Fe₄₅Pt₅₅-OA/OA; (C) Fe₂₇Pt₇₃-OA/OA; (D) Fe₆₀Pt₄₀-Cys; (E) Fe₂₄Pt₇₆-Cys.

Abbreviations: NPs, nanoparticles; OA/OA, oleic acid/oleylamine; Cys, cysteine.

Figure 8 Representative TEM images showing the uptake of FePt NPs with different components and surface coatings by human glioma U251 cells at the exposed dose of 25 μg/mL after 24 hours’ incubation.

Notes: (A) Fe₆₀Pt₄₀-OA/OA; (B) Fe₄₅Pt₅₅-OA/OA; (C) Fe₂₇Pt₇₃-OA/OA; (D) Fe₆₀Pt₄₀-Cys; (E) Fe₂₄Pt₇₆-Cys. Numerous vesicles containing the aggregative FePt NPs were visible intracellularly and were dispersed randomly in the cytoplasm. The insets in panels (A and B) are enlargements of the areas marked in white, showing the aggregative FePt NPs contained in the vesicles. The inset in panel (E) is the enlargement of the area marked in white, showing the formation of a vesicle containing an aggregate of FePt NPs.

Abbreviations: TEM, transmission electron microscopy; NPs, nanoparticles; OA/OA, oleic acid/oleylamine; Cys, cysteine.

Figure 9 Representative TEM images showing the uptake of FePt NPs with different components and surface coatings by human astrocytoma U87 cells at the exposed dose of 25 μg/mL after 24 hours’ incubation.

Notes: (A) Fe₆₀Pt₄₀-OA/OA; (B) Fe₄₅Pt₅₅-OA/OA; (C) Fe₂₇Pt₇₃-OA/OA; (D) Fe₆₀Pt₄₀- Cys; (E) Fe₂₄Pt₇₆-Cys. The release and diffusion of FePt NPs from the vesicles into the cytoplasm were observed and are marked with white arrows in panel (A); the penetration of FePt NPs through the nuclear membrane was shown and is marked with white arrows in panel (B). The adsorption of FePt NPs on the surface of cellular membrane was shown and is marked with a white arrow in panel (D).

Abbreviations: TEM, transmission electron microscopy; NPs, nanoparticles; OA/OA, oleic acid/oleylamine; Cys, cysteine.

Figure 10 Representative TEM images showing the uptake of FePt NPs with different components and surface coatings by human neuroglioma H4 cells at the exposed dose of 25 μg/mL after 24 hours’ incubation.

Notes: (A) Fe₆₀Pt₄₀-OA/OA; (B) Fe₄₅Pt₅₅-OA/OA; (C) Fe₂₇Pt₇₃-OA/OA; (D) Fe₆₀Pt₄₀- Cys; (E) Fe₂₄Pt₇₆-Cys. The release and diffusion of FePt NPs from the vesicles into the cytoplasm were observed and are marked with white arrows in panels (A and B).

Abbreviations: TEM, transmission electron microscopy; NPs, nanoparticles; OA/OA, oleic acid/oleylamine; Cys, cysteine.