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In the fight against antibiotic resistance, which is rising to dangerously high levels worldwide, new strategies based on antibiotic-conjugated biocompatible polymers bound to magnetic nanoparticles that allow the drug to be manipulated and delivered to a specific target are being proposed. Here, we report the direct surface engineering of nontoxic iron oxide nanoparticles (IONs) using biocompatible dextran (Dex) covalently linked to β-cyclodextrin (β-CD) with the ability to form non-covalent complexes with silver-sulfamethazine (SMT-Ag). To achieve a good interaction of β-CD-modified dextran with the surface of the nanoparticles, it was functionalized with diphosphonic acid (DPA) that provides strong binding to Fe atoms. The synthesized polymers and nanoparticles were characterized by various methods, such as nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and ultraviolet–visible (UV–Vis) spectroscopies, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), atomic absorption spectroscopy (AAS), dynamic light scattering (DLS), etc. The resulting magnetic ION@DPA-Dex-β-CD-SMT-Ag nanoparticles were colloidally stable in water and contained 24 μg of antibiotic per mg of the particles. When tested for in vitro antimicrobial activity on Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and fungi (yeast Candida albicans and mold Aspergillus niger), the particles showed promising potential. [ABSTRACT FROM AUTHOR]

Development of therapeutic systems to treat glioblastoma, the most common and aggressive brain tumor, belongs to priority tasks in cancer research. We have synthesized colloidally stable magnetic nanoparticles (Dh=336 nm) coated with doxorubicin (Dox) conjugated copolymers of N,N‐dimethylacrylamide and either N‐acryloylglycine methyl ester or N‐acryloylmethyl 6‐aminohexanoate. The terminal carboxyl groups of the copolymers were reacted with alendronate by carbodiimide formation. Methyl ester groups were then transferred to hydrazides for binding Dox by a hydrolytically labile hydrazone bond. The polymers were subsequently bound on the magnetic nanoparticles through bisphosphonate terminal groups. Finally, the anticancer effect of the Dox‐conjugated particles was investigated using the U‐87 glioblastoma cell line in terms of particle internalization and cell viability, which decreased to almost zero at a concentration of 100 μg of particles per ml. These results confirmed that poly(N,N‐dimethylacrylamide)‐coated magnetic nanoparticles can serve as a solid support for Dox delivery to glioblastoma cells. [ABSTRACT FROM AUTHOR]

In this study, magnetite nanoparticles were prepared and coated with poly(ethylene glycol) terminated by alendronate to ensure firm binding to the iron oxide surface. Magnetic nanoparticles, designated as magnetite coated with poly(ethylene glycol)-alendronate (Fe3O4@PEG-Ale), were characterized in terms of number-average (Dn) and hydrodynamic (Dh) size, ζ-potential, saturation magnetization, and composition. The effect of particles on blood pressure, vascular functions, nitric oxide (NO), and superoxide production in the tissues of spontaneously hypertensive rats, as well as the effect on red blood cell (RBC) parameters, was investigated after intravenous administration (1 mg Fe3O4/kg of body weight). Results showed that Fe3O4@PEG-Ale particles did negatively affect blood pressure, heart rate and RBC deformability, osmotic resistance and NO production. In addition, Fe3O4@PEG-Ale did not alter functions of the femoral arteries. Fe3O4@PEG-Ale induced increase in superoxide production in the kidney and spleen, but not in the left heart ventricle, aorta and liver. NO production was reduced only in the kidney. In conclusion, the results suggest that acute intravenous administration of Fe3O4@PEG-Ale did not produce negative effects on blood pressure regulation, vascular function, and RBCs in hypertensive rats. [ABSTRACT FROM AUTHOR]