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Increased cellular uptake of biocompatible superparamagnetic iron oxide nanoparticles into malignant cells by an external magnetic field.

Prijic S, Scancar J, Romih R, Cemazar M, Bregar VB, Znidarsic A, Sersa G - J. Membr. Biol. (2010)

Bottom Line: SPIONs, dispersed in 0.9% NaCl solution, resulted in a stable ferrofluid at physiological pH for several months.Exposure to neodymium-iron-boron magnets significantly increased the cellular uptake of SPIONs, predominantly into malignant cells.Their cellular uptake was dependent on the cell type, and their accumulation within the cells was dependent on the duration of exposure to an external magnetic field.

View Article: PubMed Central - PubMed

Affiliation: Kolektor Group, Nanotesla Institute, Stegne 29, 1521, Ljubljana, Slovenia. sara.prijic@nanotesla.si

ABSTRACT
Superparamagnetic iron oxide nanoparticles (SPIONs) are used as delivery systems for different therapeutics including nucleic acids for magnetofection-mediated gene therapy. The aim of our study was to evaluate physicochemical properties, biocompatibility, cellular uptake and trafficking pathways of the custom-synthesized SPIONs for their potential use in magnetofection. Custom-synthesized SPIONs were tested for size, shape, crystalline composition and magnetic behavior using a transmission electron microscope, X-ray diffractometer and magnetometer. SPIONs were dispersed in different aqueous media to obtain ferrofluids, which were tested for pH and stability using a pH meter and zetameter. Cytotoxicity was determined using the MTS and clonogenic assays. Cellular uptake and trafficking pathways were qualitatively evaluated by transmission electron microscopy and quantitatively by inductively coupled plasma atomic emission spectrometry. SPIONs were composed of an iron oxide core with a diameter of 8-9 nm, coated with a 2-nm-thick layer of silica. SPIONs, dispersed in 0.9% NaCl solution, resulted in a stable ferrofluid at physiological pH for several months. SPIONs were not cytotoxic in a broad range of concentrations and were readily internalized into different cells by endocytosis. Exposure to neodymium-iron-boron magnets significantly increased the cellular uptake of SPIONs, predominantly into malignant cells. The prepared SPIONs displayed adequate physicochemical and biomedical properties for potential use in magnetofection. Their cellular uptake was dependent on the cell type, and their accumulation within the cells was dependent on the duration of exposure to an external magnetic field.

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X-ray diffractogram of SPIONs. The pattern shows characteristic peaks of iron oxide maghemite (γ-Fe2O3). * Peak possibly due to an Fe–Si compound
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Fig2: X-ray diffractogram of SPIONs. The pattern shows characteristic peaks of iron oxide maghemite (γ-Fe2O3). * Peak possibly due to an Fe–Si compound

Mentions: Crystalline compounds of synthesized SPIONs were determined by XRD. SPIONs should be composed of iron oxide since the agent we used for precipitation from iron(II) sulfate heptahydrate (FeSO4 × 7H2O) and iron(III) sulfate hydrate (Fe2[SO4]3 × xH2O) was ammonium hydroxide solution (NH4OH). The XRD pattern obtained confirmed iron oxide, most probably maghemite (γ-Fe2O3), due to the value of mass magnetization and since magnetite (Fe3O4) is less stable and more prone to oxidation (Fig. 2) (Kang et al. 1996; Makovec et al. 2005). Furthermore, we calculated mean crystallite size according to the broadening of the XRD characteristic peak 311 using the Debye-Sherrer formula, which was 9.2 nm. This calculation of the iron core size is in accordance with the observations based on TEM images.Fig. 2


Increased cellular uptake of biocompatible superparamagnetic iron oxide nanoparticles into malignant cells by an external magnetic field.

Prijic S, Scancar J, Romih R, Cemazar M, Bregar VB, Znidarsic A, Sersa G - J. Membr. Biol. (2010)

X-ray diffractogram of SPIONs. The pattern shows characteristic peaks of iron oxide maghemite (γ-Fe2O3). * Peak possibly due to an Fe–Si compound
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2914263&req=5

Fig2: X-ray diffractogram of SPIONs. The pattern shows characteristic peaks of iron oxide maghemite (γ-Fe2O3). * Peak possibly due to an Fe–Si compound
Mentions: Crystalline compounds of synthesized SPIONs were determined by XRD. SPIONs should be composed of iron oxide since the agent we used for precipitation from iron(II) sulfate heptahydrate (FeSO4 × 7H2O) and iron(III) sulfate hydrate (Fe2[SO4]3 × xH2O) was ammonium hydroxide solution (NH4OH). The XRD pattern obtained confirmed iron oxide, most probably maghemite (γ-Fe2O3), due to the value of mass magnetization and since magnetite (Fe3O4) is less stable and more prone to oxidation (Fig. 2) (Kang et al. 1996; Makovec et al. 2005). Furthermore, we calculated mean crystallite size according to the broadening of the XRD characteristic peak 311 using the Debye-Sherrer formula, which was 9.2 nm. This calculation of the iron core size is in accordance with the observations based on TEM images.Fig. 2

Bottom Line: SPIONs, dispersed in 0.9% NaCl solution, resulted in a stable ferrofluid at physiological pH for several months.Exposure to neodymium-iron-boron magnets significantly increased the cellular uptake of SPIONs, predominantly into malignant cells.Their cellular uptake was dependent on the cell type, and their accumulation within the cells was dependent on the duration of exposure to an external magnetic field.

View Article: PubMed Central - PubMed

Affiliation: Kolektor Group, Nanotesla Institute, Stegne 29, 1521, Ljubljana, Slovenia. sara.prijic@nanotesla.si

ABSTRACT
Superparamagnetic iron oxide nanoparticles (SPIONs) are used as delivery systems for different therapeutics including nucleic acids for magnetofection-mediated gene therapy. The aim of our study was to evaluate physicochemical properties, biocompatibility, cellular uptake and trafficking pathways of the custom-synthesized SPIONs for their potential use in magnetofection. Custom-synthesized SPIONs were tested for size, shape, crystalline composition and magnetic behavior using a transmission electron microscope, X-ray diffractometer and magnetometer. SPIONs were dispersed in different aqueous media to obtain ferrofluids, which were tested for pH and stability using a pH meter and zetameter. Cytotoxicity was determined using the MTS and clonogenic assays. Cellular uptake and trafficking pathways were qualitatively evaluated by transmission electron microscopy and quantitatively by inductively coupled plasma atomic emission spectrometry. SPIONs were composed of an iron oxide core with a diameter of 8-9 nm, coated with a 2-nm-thick layer of silica. SPIONs, dispersed in 0.9% NaCl solution, resulted in a stable ferrofluid at physiological pH for several months. SPIONs were not cytotoxic in a broad range of concentrations and were readily internalized into different cells by endocytosis. Exposure to neodymium-iron-boron magnets significantly increased the cellular uptake of SPIONs, predominantly into malignant cells. The prepared SPIONs displayed adequate physicochemical and biomedical properties for potential use in magnetofection. Their cellular uptake was dependent on the cell type, and their accumulation within the cells was dependent on the duration of exposure to an external magnetic field.

Show MeSH
Related in: MedlinePlus