Antioxidant polymer-modified maghemite nanoparticles

• Published in: Journal of magnetism and magnetic materials 2019-03, Vol.473, p.517-526
• Main Authors: Patsula, Vitalii, Moskvin, Maksym, Siow, Wei Xiong, Konefal, Rafal, Ma, Yunn-Hwa, Horák, Daniel
• Format: Article
• Language: English
• Subjects: Antioxidant; Antioxidants; Aqueous solutions; Chemical compounds; Coating effects; Colorimetry; Conjugation; Flow cytometry; Iron oxides; Lysine; Magnetic; Magnetism; Nanoparticles; Organic chemistry; Phenolic compounds; Phenols; Phloroglucinol; Poly(l-lysine); Polyethylene glycol; Polyethyleneimine; Protective coatings; Silicon dioxide; Tannic acid
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2018.10.081

•γ-Fe2O3 was modified with silica, PEI, PEG and phenolic compound-modified poly(l-lysine).•The particles were readily internalized by the glioma cells.•Poly(l-lysine)-based coating was responsible for the increased antioxidant effects. Natural antioxidants, such as epigallocatechin-3-gallate and related phenolic compounds from tea, enhance particle cell-interactions and cellular uptake. In this study, surface of superparamagnetic iron oxide nanoparticles prepared by co-precipitation of Fe chlorides was modified with silica, polyethylenimine, poly(ethylene glycol), and poly(l-lysine) to protect the iron oxide core from redox-reactions with phenols, enhance uptake by the cells, prevent the particle aggregation, or enable conjugation with several phenol-based antioxidants. To reveal the relation between the particle uptake and chemical structure of the phenolic antioxidants, five of them were selected, namely phenol, phloroglucinol, chlorogenic, gallic, and tannic acid. After incubation of the phenol-modified nanoparticles with U87MG human glioma cells, intracellular levels of the reactive oxygen species were reduced in a similar manner, as measured by flow cytometry. Colorimetric iron assay revealed a comparable level of cell-associated particles, which was mostly independent on the applied external magnetic field. The results suggest that the poly(l-lysine)-based coating is responsible for the antioxidant effects of the particles; the phenol- and poly(l-lysine)-coatings enable effective colloidal stability in aqueous media and enhance cellular internalization of the nanoparticles.