Preparation of Fe₃O₄ magnetic nanoparticles coated with gallic acid for drug delivery

Figures & data

Figure 1 X-ray diffraction patterns for (A) pure iron oxide nanoparticles and (B) iron oxide nanoparticles coated with chitosan and gallic acid.

Figure 2 Fourier transform infrared spectra of (A) iron oxide nanoparticles, (B) iron oxide nanoparticles coated with chitosan, and (C) iron oxide nanoparticles coated with chitosan and gallic acid.

Table 1 Magnetic properties of Fe₃O₄ magnetic nanoparticles and FCG

Samples	Ms (emu/g)	Mr (emu/g)
Fe3O4	29.091	1.098
FCG	26.074	1.795

Abbreviations: FCG, iron oxide nanoparticles coated with chitosan and gallic acid; Ms, saturation magnetization; Mr, remnant magnetization.

Figure 3 Magnetization plots of (A) iron oxide magnetic nanoparticles and (B) iron oxide nanoparticles coated with chitosan and gallic acid.

Figure 4 Thermogravimetric analysis of (A) gallic acid and (B) iron oxide nanoparticles coated with chitosan and gallic acid.

Figure 5 Field emission scanning electron microscopy images of (A) iron oxide magnetic nanoparticles at 50,000× magnifications, (B) iron oxide nanoparticles at 240,000× magnification, (C) iron oxide nanoparticles coated with chitosan and gallic acid at 150,000× magnification, and (D) iron oxide nanoparticles coated with chitosan and gallic acid at 300,000× magnification.

Figure 6 Transmission electron micrographs (A) for iron oxide magnetic nanoparticles with 500 nm bar, (B) iron oxide nanoparticles coated with chitosan and gallic acid with 100 nm magnetic bar, (C) particle diameter of iron oxide nanoparticles, and (D) particle diameter of iron oxide nanoparticles coated with chitosan and gallic acid.

Figure 7 Release profiles of gallic acid from the iron oxide nanoparticles coated with chitosan and gallic acid into (A) aqueous solution of 0.0001 M Na₂CO₃, (B) phosphate-buffered solution at pH 4.8, and (C) at pH 7.4.

Table 2 Correlation coefficient (R²), rate constant (k), and half-time (t_1/2) obtained by fitting the data of the release of gallic acid from FCG into 0.0001 M Na₂CO₃ and in phosphate-buffered solution at pH 7.4 and 4.8

Aqueous Solution	Saturated release %	R^2			Rate constant (k) (mg/min)	t1/2 (min)
		Pseudo-first order	Pseudo-second order	Parabolic diffusion
Na2CO3	96.7	0.8552	0.9964	0.9542	1.18 × 10^−4,a	85
pH 7.4	58.1	0.8822	0.9909	0.9469	8.63 × 10^−5,b	181
pH 4.8	90.8	0.9867	0.9647	0.9908	2.29 × 10^−2,c	150

Notes:

a,b Estimated using pseudo-second order kinetics;

c estimated using parabolic kinetics.

Abbreviations: GA, gallic acid; FCG, iron oxide nanoparticles coated with chitosan and gallic acid.

Figure 8 Fitting graphs for gallic acid release from iron oxide nanoparticles coated with chitosan and gallic acid, into different solutions to the first-order and pseudosecond order kinetics, and the parabolic equation for 0.0001 M Na₂CO₃ (A–C), pH 7.4 (D–F), and pH 4.8 (G–I).

Figure 9 MTT assays of (A) normal human fibroblast (3T3) cell line, and anticancer activity in (B) MCF7, and (C) HT29 cell lines after 72 hours of treatment with gallic acid and iron oxide nanoparticles coated with chitosan and gallic acid at different concentrations.