Magnetic ferrite nanoparticles (MFNPs) have great application potential in biomedical fields such as magnetic resonance imaging, targeted drugs, magnetothermal therapy and gene delivery. MFNPs can migrate under the action of a magnetic field and target specific cells or tissues. However, to apply MFNPs to organisms, further modifications on the surface of MFNPs are required. In this paper, the common modification methods of MFNPs are reviewed, their applications in medical fields such as bioimaging, medical detection, and biotherapy are summarized, and the future application directions of MFNPs are further prospected.
Ferric Compounds ; Magnetic Resonance Imaging/methods* ; Magnetics ; Magnetite Nanoparticles/therapeutic use* ; Nanoparticles

PURPOSE: To determine the optimal combination of commercially available superparamagnetic iron oxide (SPIO) nanoparticles with transfection agents (TA). MATERIALS AND METHODS: Protamine sulfate (Pro) and poly-L-lysin (PLL) were incubated with ferumoxide and ferucarbotran in human mesenchymal stem cells at various concentrations, and cellular viability were evaluated. Cellular iron uptake was qualitatively and quantitatively evaluated. Cell visibility was assessed via MR imaging and the T2-relaxation time was calculated. RESULTS: The cellular viabilities with ferucarbotran were more significantly decreased than those with ferumoxide (p < 0.05). Iron uptake with ferumoxide was significantly higher than that for those with with ferucarbotran. The T2-relaxation time was observed to be shorter with ferumoxide in comparison to those with ferucarbotran (p < 0.05). Ferumoxide at a concentration of 25 microg/ml in combination with either Pro or PLL at a concentration of 3.0 microg/ml did not adversely impact cell viability, maximized iron uptake, and exhibited a lower T2-relaxation time in comparison to other combinations. CONCLUSION: Stem cells with ferumoxide exhibited a higher cellular viability and iron uptake in comparison to ferucarbotran- treated stem cells. A 25 microg/ml of ferumoxide with a 3.0 microg/ml of TA is sufficient to label mesenchymal stem cells.
Cell Survival ; Contrast Media ; Dextrans ; Ferric Compounds ; Humans ; Iron ; Magnetite Nanoparticles ; Mesenchymal Stromal Cells ; Nanoparticles ; Protamines ; Stem Cells ; Transfection

OBJECTIVETo investigate the inhibitory effect of the copolymer of magnetic nanoparticles of Fe(3)O(4) (MNPs-Fe(3)O(4)) and artesunate (ART) on myelodysplastic syndromes (MDS) cell line SKM-1 cells and the potential mechanisms.

METHODSThe protein expression levels of BCL-2, BAX, Caspase-3, and Survivin in SKM-1 cells treated with or without the co-polymer were measured by Western blot. The co-polymer-induced apoptosis rate of SKM-1 cells was measured by flow cytometry.

RESULTSThe apoptosis rate of SKM-1 cells in the copolymer groups was higher than that in both MNPs-Fe(3)O(4) and artesunate groups alone. The MNPs-Fe(3)O(4) may enhance ART-induced cell apoptosis. Western blot assay showed that the expression of survivin and BCL-2 protein were down-regulated in the ART group, and this down-regulation was even more significant in the group of copolymer of ART with MNPs-Fe(3)O(4). The levels of BAX were increased both in ART group and the copolymer of ART with MNPs-Fe(3)O(4) group, as compared with control group and MNPs-Fe(3)O(4) group. The levels of active-caspase-3 were obviously up-regulated when the ART was combined with the MNPs-Fe(3)O(4). The copolymer of ART with MNPs-Fe(3)O(4) could trigger changes in the expression levels of apoptosis-related genes in SKM-1 cells, among which up-regulation of BAX and down-regulation of survivin and BCL-2 are the 2 major alterations.

CONCLUSIONArtesunate can induce the apoptosis of SKM-1 cells, and MNPs-Fe(3)O(4) may enhance the cell apoptosis induced by ART.

Apoptosis ; Artemisinins ; Caspase 3 ; Cell Line, Tumor ; Down-Regulation ; Ferric Compounds ; Humans ; Inhibitor of Apoptosis Proteins ; Magnetite Nanoparticles ; Up-Regulation

Aqueous dispersion and stability of Fe3O4 nanoparticles remain an issue unresolved since aggregation of naked iron nanoparticles in water. In this study, we successfully synthesized different Fe3O4 super-paramagnetic nanoparticles which were modified by three kinds of materials [DSPE-MPEG2000, TiO2 and poly acrylic acid (PAA)] and further detected their characteristics. Transmission electron microscopy (TEM) clearly showed sizes and morphology of the four kinds of nanoparticles. X-ray diffraction (XRD) proved successfully coating of the three kinds of nanoparticles and their structures were maintained. Vibrating sample magnetometer (VSM) verified that their magnetic properties fitted for the super-paramagnetic function. More importantly, the particle size analysis indicated that Fe3O4@PAA had a better size distribution, biocompatibility, stability and dispersion than the other two kinds of nanoparticles. In addition, using CNE2 cells as a model, we found that all nanoparticles were nontoxic. Taken together, our data suggest that Fe3O4@PAA nanoaparticles are superior in the application of biomedical field among the four kinds of Fe3O4 nanoparticles in the future.
Ferric Compounds ; chemistry ; Magnetite Nanoparticles ; chemistry ; Microscopy, Electron, Transmission ; Spectroscopy, Fourier Transform Infrared ; Surface Properties ; Water ; chemistry ; X-Ray Diffraction

OBJECTIVETo synthesize Gal-BSA-SPIO as the magnetic resonance imaging (MRI) contrast agent targeting asialoglycoprotein (ASG) receptors in the liver and observe its role in MRI detection of hepatocellular carcinomas (HCCs).

METHODSGal-BSA was synthesized by means of reductive amination and mixed with SPIO in ice bath to prepare Gal-BSA-SPIO complex. Twenty rabbits bearing VX2 liver tumor underwent MRI enhanced by SPIO (n=10) and Gal-BSA-SPIO (n=10), and the T2 values of the liver and tumor before and after the contrast imaging were measured. Fresh human normal hepatic tissues (n=3), cirrhotic tissues (n=4) and HCC tissues (n=6) were obtained and incubated with Gal-BSA-SPIO followed by Perl's Prussian blue staining to observe the distribution of ASG receptors.

RESULTSThe size of the Gal-BSA-SPIO particles was 34.4 nm. The 20 rabbits bearing VX2 tumor, with tumor size ranging from 3 mm to 12 mm, showed isointense signal in the liver and hypointense signal in the tumor on T1WI, and isointense signal in the liver and slightly hyperintense signal in the tumor on GRE T2*WI. The signal intensity of the liver decreased slightly or moderately after administration of SPIO in the rabbits, and administration Gal-BSA-SPIO resulted in obvious reduction in the signal intensity of the liver. The signal intensities of the tumors did not exhibit obvious changes after the administration of SPIO or Gal-BSA-SPIO. Histological examination revealed numerous blue iron deposits in the Kupffer cells in SPIO group and in the hepatocytes in Gal-BSA-SPIO group, but not in the tumors in either of the groups. The human liver specimens incubated with Gal-BSA-SPIO contained numerous blue iron deposits in the hepatocyte cytoplasm and cell membrane in normal liver tissue, but the deposits were reduced in the cirrhotic tissue and almost absent in the HCC tissue.

CONCLUSIONGal-BSA-SPIO can specifically bind to ASG receptors on hepatocyte membrane to improve the tumor-liver contrast-to-noise ratio.

Animals ; Asialoglycoprotein Receptor ; chemistry ; metabolism ; Contrast Media ; chemical synthesis ; Dextrans ; Female ; Ferric Compounds ; chemistry ; Ferrosoferric Oxide ; chemistry ; Galactose ; chemistry ; Humans ; Image Enhancement ; methods ; Image Processing, Computer-Assisted ; Liver ; metabolism ; Liver Neoplasms ; diagnosis ; metabolism ; pathology ; Liver Neoplasms, Experimental ; pathology ; Magnetic Resonance Imaging ; methods ; Magnetite Nanoparticles ; Male ; Rabbits ; Serum Albumin, Bovine ; chemistry

Urokinase plasminogen activator receptor (uPAR) is a membrane protein which is attached to the cellular external membrane. The uPAR expression can be observed both in tumor cells and in tumor-associated stromal cells. Thus, in the present study, the human amino-terminal fragment (hATF), as a targeting element to uPAR, is used to conjugate to the surface of superparamagnetic iron nanoparticle (SPIO). Flowcytometry was used to examine the uPAR expression in different tumor cell lines. The specificity of hATF-SPIO was verified by Prussian blue stain and cell phantom test. The imaging properties of hATF-SPIO were confirmed in vivo magnetic resonance imaging (MRI) of uPAR-elevated colon tumor. Finally, the distribution of hATF-SPIO in tumor tissue was confirmed by pathological staining. Results showed that the three cells in which we screened, presented different expression characteristics, i. e., Hela cells strongly expressed uPAR, HT29 cells moderately expressed uPAR, but Lovo cells didn't express uPAR. In vitro, after incubating with Hela cells, hATF-SPIO could specifically combined to and be subsequently internalized by uPAR positive cells, which could be observed via Prussian blue staining. Meanwhile T2WI signal intensity of Hela cells, after incubation with targeted probe, significantly decreased, and otherwise no obvious changes in Lovo cells both by Prussian blue staining and MRI scans. In vivo, hATF-SPIO could be systematically delivered to HT29 xenograft and accumulated in the tumor tissue which was confirmed by Prussian Blue stain compared to Lovo xenografts. Twenty-four hours after injection of targeting probe, the signal intensity of HT29 xenografts was lower than Lovo ones which was statistically significant. This targeting nanoparticles enabled not only in vitro specifically combining to uPAR positive cells but also in vivo imaging of uPAR moderately elevated colon cancer lesions.
Cell Line, Tumor ; Colonic Neoplasms ; diagnosis ; Ferric Compounds ; Humans ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; chemistry ; Molecular Imaging ; methods ; Receptors, Urokinase Plasminogen Activator ; chemistry ; Staining and Labeling

OBJECTIVETo explore the feasibility and fluorescence characteristics of CFSE negative staining for in vivo cell imaging of super paramagnetic iron oxide nanoparticles (SPIO) phagocytosed by mouse mononuclear macrophage leukemia cells-RAW264.7.

METHODSAfter labeled with SPIO, the RAW264.7 macrophages were stained with Prussian blue stain and CFSE fluorescence negative stain step by step. Furthermore, trypan blue staining was used to evaluate cell viability of cells which stained with CFSE. At last, laser scanning confocal microscope was used to measure SPIO in cells through CFSE fluorescence negative stain method.

RESULTSSPIO within RAW264.7 macrophages showed blue in Prussian's blue staining, while showed negative area in CFSE negative staining. Good consistencies between Prussian's blue staining and CFSE negative staining were observed. In addition, RAW264.7 macrophages showed high viability after SPIO/CFSE dual-labeled method, proved by typan stain.

CONCLUSIONThe CFSE fluorescence negative staining may be used for detecting SPIO that phagocytosed by RAW264.7 macrophages and it is showed good consistency that confirmed one another when compared to classic Prussian' blue staining.

Animals ; Cell Line, Tumor ; Cell Survival ; Contrast Media ; Ferric Compounds ; Ferrocyanides ; Fluoresceins ; Fluorescence ; Leukemia ; Macrophages ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; Mice ; Negative Staining ; Phagocytosis ; Succinimides

The aim of this study was to label rabbit bone derived mesenchymal stem cells (BMSCs) with superparamagnetic iron oxide particles (SPIO) and to study the effects of magnetic labeling on the multi-differentiation of BMSCs. Rabbit BMSCs were isolated, purified, expanded, then coincubated with SPIO(25 microg/ml) complexed to protamine sulfate (Pro) transfection agents overnight. Prussian blue staining and transmission electron microscopy were performed to show intracellular iron. Cell differentiation was evaluated. Both labeled and unlabeled BMSCs were subjected to osteogenic, adipogenic and chondrogenic differentiation to assess their differentiation capacity for 21 d. Osteogenic cells were stained with alizarin red to reveal calcium deposition, adipogenic cells were stained with oil redO' respectively. Chondrogenic cells stained with Safranin-O, glycosamino glycans, and type II collagen production was assessed by standard immunohistochemistry. Cell with immunohistochemistry staining were detected by polarized light microscopy and analysed by Image-Pro Plus software. The results showed that intracytoplasmic nanoparticles were stained with Prussian blue and observed by transmission electron microscopy clearly except the unlabeled control. As compared with the nonlabeled cells, it showed no statistically significant difference on the differentiation of the labeled BMSCs. And the differentiation of the labeled cells were unaffected by the endosomal incorporation of SPIO. In summary, BMSCs can be labeled with SPIO without significant change in cell multi-differentiation capacity.
Adipocytes ; cytology ; Animals ; Bone Marrow Cells ; cytology ; Cell Differentiation ; physiology ; Cell Proliferation ; Cell Tracking ; Cells, Cultured ; Chondrocytes ; cytology ; Dextrans ; Ferric Compounds ; Magnetite Nanoparticles ; Mesenchymal Stromal Cells ; cytology ; Osteoblasts ; cytology ; Rabbits ; Staining and Labeling

BACKGROUNDMagnetic resonance (MR) molecular imaging can detect abnormalities associated with disease at the level of cell and molecule. The epidermal growth factor receptor (EGFR) plays an important role in the development of lung cancer. This study aimed to explore new MR molecular imaging targeting of the EGFR on lung cancer cells.

METHODSWe attached ultra-small superparamagnetic iron oxide (USPIO) particles to cetuximab (C225) anti-human IgG using the carbodiimide method. We made the molecular MR contrast agents C225-USPIO and IgG-USPIO, the latter as a control reagent, and determined concentrations according to the Fe content. Lung cancer A549 cells were cultured and immunocytochemistry (SP) was used to detect the expression of EGFR on cells. We detected the binding rate of C225-USPIO to A549 cells with immunofluorescence staining and flow cytometry. We cultured A549 cells with C225-USPIO at a Fe concentration of 50 µg/ml and assayed the binding of C225-USPIO after 1 hour with Prussian blue staining and transmission electron microscopy (TEM). We determined the effects on imaging of the contrast agent targeted to cells using a 4.7T MRI. We did scanning on the cells labeled with C225-USPIO, IgG-USPIO, and distilled water, respectively. The scanning sequences included axial T1WI, T2WI.

RESULTSImmunocytochemical detection of lung cancer A549 cells found them positive for EGFR expression. Immunofluorescence staining and flow cytometry after cultivation with different concentrations of C225-USPIO showed the binding rate higher than the control. Prussian blue staining and transmission electron microscopy revealed that in the C225-USPIO contrast agent group of cells the particle content of Fe in cytoplasmic vesicles or on surface was more than that in the control group. The 4.7T MR imaging (MRI) scan revealed the T2WI signal in the C225-USPIO group of cells decreased significantly more than in unlabeled cells, but there was no significant difference between the time gradients.

CONCLUSIONSWe successfully constructed the molecular imaging agent C225-USPIO targeting the EGFR of A549 lung cancer cells. The imaging agent showed good targeting effect and specificity, and reduced MRI T2 value significantly, thus such molecular contrast agents could provide a new way to measure EGFR levels.

Antibodies, Monoclonal ; chemistry ; Antibodies, Monoclonal, Humanized ; Cell Line, Tumor ; Cetuximab ; Contrast Media ; chemistry ; Dextrans ; chemistry ; Ferric Compounds ; chemistry ; Humans ; Immunohistochemistry ; Lung Neoplasms ; metabolism ; Magnetic Resonance Imaging ; methods ; Magnetite Nanoparticles ; chemistry ; Microscopy, Electron, Transmission ; Receptor, Epidermal Growth Factor ; metabolism

Folic acid-O-carboxymethyl chitosan ultrasmall superparamagnetic iron oxide nanoparticles (FA-OCMCS-USPIO-NPs) are a novel molecular targeting MR contrast agent. This paper reperts the pharmacokinetics and magnetic resonance response characteristics of FA-OCMCS-USPIO-NPs in normal rats and mice, and discussed its distributing regularity in animals, providing basis for tumor targeting imaging. O-phenanthroline method was used to determine iron content in rats' plasma and mice's organs following high and low doses of nanoparticles injected through tail vein, and the blood concentration-time curve was drawn, the calculated t1/2 of two groups were greater than 7 h. The results of tissue distribution showed that only a small part of nanoparticles were swallowed by the liver and spleen, while none in the heart, lung and kidney. At the same times, the phagocytosis of nanoparticles did not change with the dose. The results of MRI showed that renal excretion occurred 4 hours after injection, and signal to noise ratio (SNR) of liver and kidney returned to normal levels 24 hours after injection. There were no nanoparticles in the lungs. So a part of nanoparticles escaped from phagocytosis of liver and spleen, and it owned lower toxicity and longer half-life. indicated its use for tumor-targeting imaging. All of these indicated its use for tumor-targeting imaging.
Animals ; Area Under Curve ; Chitosan ; administration & dosage ; analogs & derivatives ; chemistry ; pharmacokinetics ; Contrast Media ; administration & dosage ; chemistry ; pharmacokinetics ; Dose-Response Relationship, Drug ; Drug Carriers ; Ferric Compounds ; administration & dosage ; chemistry ; pharmacokinetics ; Folic Acid ; administration & dosage ; chemistry ; pharmacokinetics ; Injections, Intravenous ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; administration & dosage ; chemistry ; Male ; Mice ; Nanoparticles ; Particle Size ; Phagocytosis ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tissue Distribution