Superparamagnetic iron oxide nanoparticles (SPIOn) are widely used as a contrast agent for cell labeling. Macrophages are the first line of defense of organisms in contact with nanoparticles after their administration. In this study we investigated the effect of silica-coated nanoparticles (γ-Fe2O3-SiO2) with or without modification by an ascorbic acid (γ-Fe2O3-SiO2-ASA), which is meant to act as an antioxidative agent on rat peritoneal macrophages. Both types of nanoparticles were phagocytosed by macrophages in large amounts as confirmed by transmission electron microscopy and Prusian blue staining, however they did not substantially affect the viability of exposed cells in monitored intervals. We further explored cytotoxic effects related to oxidative stress, which is frequently documented in cells exposed to nanoparticles. Our analysis of double strand breaks (DSBs) marker γH2AX showed an increased number of DSBs in cells treated with nanoparticles. Nanoparticle exposure further revealed only slight changes in the expression of genes involved in oxidative stress response. Lipid peroxidation, another marker of oxidative stress, was not significantly affirmed after nanoparticle exposure. Our data indicate that the effect of both types of nanoparticles on cell viability, or biomolecules such as DNA or lipids, was similar; however the presence of ascorbic acid, either bound to the nanoparticles or added to the cultivation medium, worsened the negative effect of nanoparticles in various tests performed. The attachment of ascorbic acid on the surface of nanoparticles did not have a protective effect against induced cytotoxicity, as expected.

• Keywords
• Cytotoxicity, Macrophages, Nanoparticles, Oxidative stress,
• MeSH
• Antioxidants metabolism   toxicity   MeSH
• Rats MeSH
• Cells, Cultured MeSH
• Ascorbic Acid metabolism   toxicity   MeSH
• Magnetite Nanoparticles toxicity   MeSH
• Macrophages, Peritoneal drug effects   metabolism   MeSH
• Rats, Wistar MeSH
• Drug Synergism MeSH
• Cell Survival drug effects   physiology   MeSH
• Dose-Response Relationship, Drug MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Antioxidants MeSH
• Ascorbic Acid MeSH
• Magnetite Nanoparticles MeSH

Manganese-zinc ferrite nanoparticles were synthesized by using a hydrothermal treatment, coated with silica, and then tested as efficient cellular labels for cell tracking, using magnetic resonance imaging (MRI) in vivo. A toxicity study was performed on rat mesenchymal stem cells and C6 glioblastoma cells. Adverse effects on viability and cell proliferation were observed at the highest concentration (0.55 mM) only; cell viability was not compromised at lower concentrations. Nanoparticle internalization was confirmed by transmission electron microscopy. The particles were found in membranous vesicles inside the cytoplasm. Although the metal content (0.42 pg Fe/cell) was lower compared to commercially available iron oxide nanoparticles, labeled cells reached a comparable relaxation rate R 2, owing to higher nanoparticle relaxivity. Cells from transgenic luciferase-positive rats were used for in vivo experiments. Labeled cells were transplanted into the muscles of non-bioluminescent rats and visualized by MRI. The cells produced a distinct hypointense signal in T2- or T2*-weighted MR images in vivo. Cell viability in vivo was verified by bioluminescence.

• Keywords
• cell labeling, cell transplantation, doping, magnetic resonance imaging, nanoparticles,
• Publication type
• Journal Article MeSH

INTRODUCTION: Rat mesenchymal stem cells (rMSCs) labeled with 1) poly-l-lysine-coated superparamagnetic iron oxide nanoparticles or 2) silica-coated cobalt-zinc-iron nanoparticles were implanted into the left brain hemisphere of rats, to assess their effects on the levels of oxidative damage to biological macromolecules in brain tissue. METHODS: Controls were implanted with unlabeled rMSCs. Animals were sacrificed 24 hours or 4 weeks after the treatment, and the implantation site along with the surrounding tissue was isolated from the brain. At the same intervals, parallel groups of animals were scanned in vivo by magnetic resonance imaging (MRI). The comet assay with enzymes of excision DNA repair (endonuclease III and formamidopyrimidine-DNA glycosylase) was used to analyze breaks and oxidative damage to DNA in the brain tissue. Oxidative damage to proteins and lipids was determined by measuring the levels of carbonyl groups and 15-F2t-isoprostane (enzyme-linked immunosorbent assay). MRI displayed implants of labeled cells as extensive hypointense areas in the brain tissue. In histological sections, the expression of glial fibrillary acidic protein and CD68 was analyzed to detect astrogliosis and inflammatory response. RESULTS: Both contrast labels caused a similar response in the T2-weighted magnetic resonance (MR) image and the signal was clearly visible within 4 weeks after implantation of rMSCs. No increase of oxidative damage to DNA, lipids, or proteins over the control values was detected in any sample of brain tissue from the treated animals. Also, immunohistochemistry did not indicate any serious tissue impairment around the graft. CONCLUSION: Both tested types of nanoparticles appear to be prospective and safe labels for tracking the transplanted cells by MR.

• Keywords
• MRI, cell transplantation, comet assay, genotoxicity, lipid peroxidation, protein oxidative damage,
• MeSH
• Dinoprost analogs & derivatives   MeSH
• Enzyme-Linked Immunosorbent Assay MeSH
• Isoprostanes analysis   metabolism   MeSH
• Cobalt chemistry   MeSH
• Metal Nanoparticles administration & dosage   chemistry   toxicity   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Mesenchymal Stem Cells chemistry   MeSH
• Brain diagnostic imaging   drug effects   metabolism   MeSH
• Silicon Dioxide chemistry   MeSH
• Rats, Inbred Lew MeSH
• Prospective Studies MeSH
• Tissue Extracts MeSH
• Mesenchymal Stem Cell Transplantation * MeSH
• Ferric Compounds chemistry   MeSH
• Iron chemistry   MeSH
• Zinc chemistry   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• 8-epi-prostaglandin F2alpha MeSH Browser
• Dinoprost MeSH
• ferric oxide MeSH Browser
• Isoprostanes MeSH
• Cobalt MeSH
• Silicon Dioxide MeSH
• Tissue Extracts MeSH
• Ferric Compounds MeSH
• Iron MeSH
• Zinc MeSH

INTRODUCTION: Magnetic resonance (MR) imaging is suitable for noninvasive long-term tracking. We labeled human induced pluripotent stem cell-derived neural precursors (iPSC-NPs) with two types of iron-based nanoparticles, silica-coated cobalt zinc ferrite nanoparticles (CZF) and poly-l-lysine-coated iron oxide superparamagnetic nanoparticles (PLL-coated γ-Fe2O3) and studied their effect on proliferation and neuronal differentiation. MATERIALS AND METHODS: We investigated the effect of these two contrast agents on neural precursor cell proliferation and differentiation capability. We further defined the intracellular localization and labeling efficiency and analyzed labeled cells by MR. RESULTS: Cell proliferation was not affected by PLL-coated γ-Fe2O3 but was slowed down in cells labeled with CZF. Labeling efficiency, iron content and relaxation rates measured by MR were lower in cells labeled with CZF when compared to PLL-coated γ-Fe2O3. Cytoplasmic localization of both types of nanoparticles was confirmed by transmission electron microscopy. Flow cytometry and immunocytochemical analysis of specific markers expressed during neuronal differentiation did not show any significant differences between unlabeled cells or cells labeled with both magnetic nanoparticles. CONCLUSION: Our results show that cells labeled with PLL-coated γ-Fe2O3 are suitable for MR detection, did not affect the differentiation potential of iPSC-NPs and are suitable for in vivo cell therapies in experimental models of central nervous system disorders.

• Keywords
• cell differentiation, ferrites, magnetic resonance imaging, neural precursors, superparamagnetic iron oxide nanoparticles,
• MeSH
• Cell Differentiation * MeSH
• Fibroblasts cytology   MeSH
• Immunoenzyme Techniques MeSH
• Induced Pluripotent Stem Cells cytology   MeSH
• Contrast Media chemistry   MeSH
• Cells, Cultured MeSH
• Real-Time Polymerase Chain Reaction MeSH
• Humans MeSH
• Lysine chemistry   MeSH
• Magnetic Resonance Imaging methods   MeSH
• Magnetite Nanoparticles chemistry   MeSH
• Neurons cytology   MeSH
• Lung cytology   MeSH
• Fetus cytology   MeSH
• Cell Proliferation MeSH
• Flow Cytometry MeSH
• Microscopy, Electron, Transmission MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Contrast Media MeSH
• Lysine MeSH
• Magnetite Nanoparticles MeSH