Poly(ethylene glycol)-Alendronate-Coated Magnetite Nanoparticles Do Not Alter Cardiovascular Functions and Red Blood Cells’ Properties in Hypertensive Rats

Figures

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  Figure 1. (a) 1H NMR spectrum of PEG-Ale and (b) scheme of Fe3O4@PEG-Ale nanoparticles. PEG-Ale, poly(ethylene glycol)-alendronate.

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  Figure 2. Time course of the experimental protocol. Basal recordings of blood pressure and heart rate were determined at the beginning (Bas) and at the end of the experiment as the average values of ~120-s time periods between 16–20 min and 138–142 min of the experiment. Then, the rats were decapitated (Decap.). Bas, baseline; Fe3O4@PEG-Ale, Fe3O4@PEG-alendronate nanoparticles.

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  Figure 3. Transmission electron microscope micrographs of (a) Fe3O4 and (b) Fe3O4@PEG-Ale nanoparticles.

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  Figure 4. (a) Hysteresis loops of pure Fe3O4 nanoparticles at 5 and 300 K, (b) thermogravimetric analysis of Fe3O4@PEG-Ale, and (c) FTIR spectra of Fe3O4 (red) and Fe3O4@PEG-Ale nanoparticles (black).

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  Figure 5. (a) Mean arterial pressure and (b) heart rate of rats 10–14 min before infusion, during infusion, and 100 min after infusion of nanoparticles. The values represent the mean ± SEM, n = 6–7 per group. Fe3O4@PEG-Ale, Fe3O4@PEG-alendronate nanoparticles; MAP, mean arterial pressure; HR, heart rate; Bas, basal value; Inf, value determined during infusion; End, value at the end of the experiment; bpm, beats per minute.

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  Figure 6. (a) Red blood cell deformability, (b) osmotic resistance, and (c) nitric oxide production in spontaneously hypertensive rats before and 100 min after Fe3O4@PEG-Ale nanoparticle infusion. The values represent the mean ± SEM, n = 3 (deformability and osmotic resistance), n = 5 (NO production).

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  Figure 7. Nitric oxide synthase activities in (a) aorta, (b) left heart ventricle, (c) liver, (d) hypothalamus, and (e) kidney after IV administration of Fe3O4@PEG-Ale nanoparticles in rats. The values represent the mean ± SEM. * p < 0.05 vs. control group, n = 6–7 per group. Cont, control; NOS, nitric oxide synthase; Fe3O4@PEG-Ale, Fe3O4@PEG-alendronate nanoparticles.

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  Figure 8. Superoxide production in (a) aorta, (b) left heart ventricle, (c) liver, (d) spleen, and (e) kidney after IV administration of Fe3O4@PEG-Ale nanoparticles in rats. The values represent the mean ± SEM * p < 0.05 vs. control group, n = 5–6 per group. Cont, control; Fe3O4@PEG-Ale, Fe3O4@PEG-alendronate nanoparticles.

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  Figure 9. Maximal depolarization-induced contractions produced by (a) KPSS and (b) serotonin (5-hydroxytryptamine)-induced contractions in the absence and presence of NO synthase inhibitor L-NAME. The values represent mean ± SEM. * p < 0.05 vs. 5-HT, n = 12 per group. Cont, control; Fe3O4@PEG-Ale, Fe3O4@PEG-alendronate nanoparticles; KPSS, high concentration of potassium (125 mmol/L)-containing physiological saline solution; 5-HT, serotonin; L-NAME, N(ω)-nitro-L-arginine methyl ester.

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  Figure 10. (a) Sodium nitroprusside-induced relaxation and acetylcholine-induced relaxations (b) in the absence and (c) presence of L-NAME in the femoral arteries. The values represent the mean ± SEM, n = 12 per group. * p < 0.05 vs. the maximal relaxation in the same group. Cont, control; Fe3O4@PEG-Ale, Fe3O4@PEG-alendronate nanoparticles, ACh, acetylcholine; SNP, sodium nitroprusside.