The nano-magnetic ferrofluid was prepared by chemical coprecipitation and its acute toxicology was investigated. The effective diameter (Eff. Diam. ) of the magnetic particles was about 19.9 nm, and the concentration of the ferrofluid was 17. 54 mg/ml. The acute toxic reaction and the main viscera pathological morphology of mice were evaluated after oral, intravenous and intraperitoneal administration of the nano-magnetic ferrofluid of different doses respectively. Half lethal dose (LD50) > 2104. 8 mg/kg,maximum non-effect dose (ED0) = 320. 10mg/kg with oral; LDs,> 438. 50 mg/kg, EDo = 160. 05 mg/kg with intravenous route; and LDso >1578. 6 mg/kg, ED0 = 320. 10 mg/kg with intraperitoneal administration. Degeneration and necrosis of viscera were not found. So the nano-magnetic ferrofluid, of which toxicity is very low, may be used as a drug carrier.
Ferrosoferric Oxide/chemical synthesis ; Ferrosoferric Oxide/*toxicity ; Magnetics ; Nanostructures/*toxicity

We prepared Fe3O4 magnetic nanoparticles (MNPs) with the size of 10 nm by chemical coprecipitation. The effects of six aqueous-organic solvents, including tetrahydrofuran, dioxane, acetone, N, N-Dimethylformamide, methylalcohol, and Dimethyl Sulfoxide, on peroxidase mimetic activity of Fe3O4 MNPs were studied and compared with that of horseradish peroxidase (HRP). The relative activity of Fe3O4 MNPs droped sharply as the elevation of organic solvent concentration increased from 30% to 75% (V/V). In 15% organic solutions, the optimum activity of Fe3O4 MNPs was observed around 50 degrees C, under pH 3.6. After being treated at different temperatures and pH in 15% organic solutions, even under 75% concentration, Fe3O4 MNPs still preserved most of the activity when reacting in aqueous phase. The catalytic performances of Fe3O4 MNPs under given conditions were generally more superior to that of HRP. For it costs lower and it is easy to be prepared and segregated magnetically for recycle, to use the magnetic nanoparticles as a substitution for HRP has potential to be applied into organic catalysis.
Acetone ; chemistry ; Biomimetics ; Catalysis ; Dioxanes ; chemistry ; Ferrosoferric Oxide ; chemistry ; Furans ; chemistry ; Hydrogen-Ion Concentration ; Magnetite Nanoparticles ; chemistry ; Organic Chemicals ; chemistry ; Peroxidase ; metabolism ; Solvents ; Temperature

Effects of different procedures of magnetic nanoparticles into the liposome structure on the distribution of magnetic particles in the liposome were investigated. Magnetic liposomes with high-encapsulating rate of cisplatin (CDDP) were obtained. Fe3O4 magnetic nanoparticles which was modified by organic functional group on surface was synthesized by an one-step modified hydrothermal method. The CDDP magnetic liposomes were prepared by a film scattering-ultrasonic technique and the concentrations of CDDP in the liposomes were measured by graphite furnace atomic absorbance spectroscopy. Magnetic liposomes with different microstructure were prepared by the two different procedures, where the magnetic particles were combined with phospholipid before the film preparation to form liposome in procedure I, and drug solution and the magnetic particles were mixed before hydrating the lipids film to form liposome in procedure II. The liposome structure was observed by transmission electron microscope (TEM). The CDDP magnetic liposomes were prepared by the optimized method which was selected by orthogonal test. Encapsulation rate of the magnetic particles distributed in the phospholipid bilayer through the procedure I was 34.90%. While liposome, produced by the procedure II technique, contained magnetic particles in the interior aqueous compartment, which encapsulation rate was 28.34%. Encapsulation rates of both I and II were higher than that of conventional liposome. The release profile of all the three different liposomes in vitro fitted with a first-order equation. Because of distribution of magnetic particles in the phospholipid bilayer, the skeleton of phospholipid bilayer was changed. The releasing tl/2 of magnetic liposomes produced by the procedure I technique is 9 h, which is shorter than that of the other two liposomes. Assemble of magnetic nanoparticles into the structure of liposome was succeeded by the procedure I, which showed superiority than by procedure II whatever in CDDP liposome encapsulation efficiency and content of the magnetic particles and would ensure sustained-release character.
Antineoplastic Agents ; administration & dosage ; chemistry ; Cisplatin ; administration & dosage ; chemistry ; Drug Compounding ; methods ; Ferrosoferric Oxide ; chemistry ; Liposomes ; chemistry ; Magnetite Nanoparticles ; chemistry ; Nanoconjugates ; administration & dosage ; chemistry ; Particle Size

Coprecipitation method was used to prepare triiron tetroxide magnetic nanoparticles enclosed in L-DOPA, and then EDC was used to activate the carboxyl group of L-DOPA after the nanoparticles were synthesized. The carboxyl group of L-DOPA formed amide bond with specific amino on the aptamer by dehydration condensation reaction. The surfaces of magnetic nanoparticles were modified with aptamer and L-DOPA. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), nanoparticle size analysis (SEM), magnetic measurement (VSM) and other testing methods were used to detect the magnetic nanoparticles in different stages. The endothelial progeni-tor cells (EPCs) were cocultured with the surface modified magnetic nanoparticles to evaluate cell compatibility and the combination effect of nanoparticles on EPCs in a short period of time. Directional guide of the surface-modified magnetic nanoparticles to endothelial progenitor cells (EPCs) was evaluated under an applied magnetic field and simulated dynamic blood flow condition. The results showed that the prepared magnetic nanoparticles had good magnetic response, good cell compatibility within a certain range of the nanoparticle concentrations. The surface modified nanoparticles could combine with EPCs effectively in a short time, and those nanoparticles combined EPCs can be directionally guided on to a stent surface under the magnetic field in the dynamic flow environment.
Endothelial Progenitor Cells ; cytology ; drug effects ; Ferrosoferric Oxide ; chemistry ; Humans ; Levodopa ; chemistry ; Magnetite Nanoparticles ; chemistry ; Spectroscopy, Fourier Transform Infrared ; X-Ray Diffraction

OBJECTIVETo investigate the magnetic resonance (MR) signal features of superparamagnetic iron oxide (SPIO) with different particle size and concentration.

METHODSThe superparamagnetic iron oxide with different concentration and particle size was scanned by magnetic resonance; T1, T2 and T2(*) values of each group were recorded to evaluate the features of MR signals.

RESULTSThe T1 value of SPIO with different particle size had negative linear relationship with concentration. In low concentration the T2 and T2(*) values were elevated markedly with the particle size decreased; while in high concentration the T2 and T2(*)values were elevated gently with particle size decreased. lg(T2), particle size and concentration of SPIO had linear relationship.

CONCLUSIONSSPIO affects magnetic resonance signal mainly with effect on T1 and T2. T2 value can be regarded as the major detection index in the magnetic resonance scan of SPIO. There is a linear relationship among particle size, SPIO concentration and lg(T2) value.

Contrast Media ; pharmacology ; Dose-Response Relationship, Drug ; Ferrosoferric Oxide ; chemistry ; pharmacology ; Humans ; Image Enhancement ; Magnetic Resonance Imaging ; methods ; Magnetite Nanoparticles ; chemistry ; Particle Size

AIMTo investigate whether the biological process of superparamagnetic iron oxide (SPIO)-labeled human mesenchymal stem cells (hMSCs) may be monitored non-invasively by using in vivo magnetic resonance (MR) imaging with conventional 1.5-T system examinations in corpus cavernosa of rats and rabbits.

METHODSThe labeling efficiency and viability of SPIO-labeled hMSCs were examined with Prussian blue and Tripan blue, respectively. After SPIO-labeled hMSCs were transplanted to the corpus cavernosa of rats and rabbits, serial T2-weighted MR images were taken and histological examinations were carried out over a 4-week period.

RESULTShMSCs loaded with SPIO compared to unlabeled cells had a similar viability. For SPIO-labeled hMSCs more than 1 X 10 (5) concentration in vitro, MR images showed a decrease in signal intensity. MR signal intensity at the areas of SPIO-labeled hMSCs in the rat and rabbit corpus cavernosa decreased and was confined locally. After injection of SPIO-labeled hMSCs into the corpus cavernosum, MR imaging demonstrated that hMSCs could be seen for at least 12 weeks after injection. The presence of iron was confirmed with Prussian blue staining in histological sections.

CONCLUSIONSPIO-labeled hMSCs in corpus cavernosa of rats and rabbits can be evaluated non-invasively by molecular MR imaging. Our findings suggest that MR imaging has the ability to test the long-term therapeutic potential of hMSCs in animals in the setting of erectile dysfunction.

Animals ; Cell Survival ; Contrast Media ; administration & dosage ; Dextrans ; Ferrosoferric Oxide ; Humans ; Iron ; Magnetic Resonance Imaging ; methods ; Magnetite Nanoparticles ; Male ; Mesenchymal Stem Cell Transplantation ; methods ; Oxides ; Penis ; pathology ; Rabbits ; Rats ; Staining and Labeling ; methods

PEG-modified magnetic Fe3O4 (Fe3O4-PEG) nanoparticles were sythesized using a solvothermal reaction and characterized with transmission electron microscopy (TEM) and thermo gravimetric analysis (TGA). The photothermal effect and photothermal destruction of cancer cells were evaluated. Then the doxorubicin loaded Fe3O4-PEG (DOX-Fe3O4-PEG) nanoparticles were prepared. The cytotoxicity and combined chemotherapy/photothermal therapy (PTT) effect were investigated. Uniform PEG coated Fe3O4 nanoparticles with particle size of 155 nm were obtained in the experiment. The loading and release of doxorubicin on Fe3O4-PEG were pH-dependent. The drug loading capacity in water was 21%. The results of MTT indicated a good biocompatiblity of Fe3O4-PEG nanoparticles and high cytotoxicity of DOX-Fe3O4-PEG. In combined therapy experiment, photothermal therapy demonstrated unambiguously enhanced chemotherapy efficacy. In conclusion, the obtained Fe3O4-PEG nanoparticles which exhibit good photothermal effect and drug loading capacity can be used for chemotherapy and photothermal therapy. The synergetic anti-tumor activity indicates the potential for the combined application of chemotherapy and photothermal therapy in cancer treatment.
Antibiotics, Antineoplastic ; administration & dosage ; pharmacology ; Cell Survival ; drug effects ; Doxorubicin ; administration & dosage ; pharmacology ; Drug Carriers ; Ferrosoferric Oxide ; chemistry ; Humans ; Hyperthermia, Induced ; MCF-7 Cells ; Magnetite Nanoparticles ; chemistry ; Particle Size ; Polyethylene Glycols ; chemistry

OBJECTIVETo study the effect of superparamgnetic iron oxides (ferumoxides) on the survival and proliferation of neural stem cells (NSCs) and determine the optimal ferumoxides concentration for labeling.

METHODSBone marrow stromal cells (BMSCs) were obtained from rat femoral marrow and cultured in vitro to induce their differentiation into NSCs. Ferumoxides labeling of the NSCs was performed with different final concentrations of ferumoxides, and the labeling efficiency and viability of the labeled NSCs were evaluated by Prussian blue staining, MTT assay, flow cytometry and transmission electron microscope.

RESULTSThe NSCs could be effectively labeled with ferumoxides with a labeling efficiency of around 90%. Prussian blue staining showed numerous fine granules with blue staining in the cytoplasm of the labeled NSCs, and the intensity of the blue staining was in positive correlation with the ferumoxide concentration for labeling. Transmission electron microscopy of the labeled NSCs revealed the presence of numerous vesicles spreading in the cytoplasm and filled with electron-dense magnetic iron particles. The ferumoxides vesicles increased with the labeling concentration of ferumoxides, and at the final concentration exceeding 25 microg/ml, ferumoxides vesicles in the NSCs gave rise to conglomeration which hampered observation of the cellular ultrastructure by transmission electron microscope. The results of flow cytometry and MTT assay demonstrated that the cell viability, proliferation, differentiation and apoptosis of the labeled cells were affected by ferumoxides at the concentration above 25 microg/ml, but such effects could be minimal at lower concentrations.

CONCLUSIONFerumoxides might be feasible for in vitro labeling of the NSCs with the optimal concentration of 25 microg/ml.

Animals ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Dextrans ; Ferrosoferric Oxide ; Iron ; pharmacology ; Magnetite Nanoparticles ; Male ; Microscopy, Electron, Transmission ; Neurons ; cytology ; ultrastructure ; Oxides ; pharmacology ; Rats ; Stem Cells ; cytology ; ultrastructure

OBJECTIVETo explore the feasibility of in vivo tracking of bone marrow mesenchymal stem cells (BMSCs) labeled with superparamagnetic iron oxide (SPIO) by magnetic resonance imaging (MRI) in rats after cerebral ischemia, and to analyze the influence of stem cell therapy on the volume of cerebral infarction.

METHODSThe samples of rat bone marrow were collected. BMSCs separated by density gradient centrifugation were cultivated and harvested until the third passage. BMSCs were labeled with SPIO, which was mixed with poly-L-lysine. The labeling efficiency was evaluated by Prussian blue staining. Transient middle cerebral arterial occlusion (MCAO) was performed successfully in 18 adult Sprague-Dawley rats that scored from 6 to 12 by the modified neurological severity test. The 18 rats were then randomly divided into group A, B, and C, with 6 rats in each group and Group C was regarded as control group. BMSCs were injected into the contralateral cortex of ischemia in group A, ipsilateral corpora striata in group B, while D-Hank's solution was injected into ipsilateral corpora striata (group C) 24 hours after MCAO. MRI was performed 1 day after MCAO, 1 day and 14 days after transplantation. The volume of infarcted brain tissue was measured and analyzed. Prussian blue staining of brain tissues was performed to identify the migration of BMSCs.

RESULTSThe labeling efficiency of BMSCs with SPIO was 96%. The transplanted BMSCs migrated to the ischemic hemisphere along the corpus callosum and to the border of the infarction, which was confirmed by MRI and Prussian blue staining. The changes of infarction volume were not significantly different among these three groups.

CONCLUSIONSMRI is feasible for in vivo tracking of BMSCs labeled with SPIO in rats. The stem cell therapy may not be able to affect the volume of cerebral infarction.

Animals ; Brain ; pathology ; Cells, Cultured ; Dextrans ; Disease Models, Animal ; Feasibility Studies ; Ferrosoferric Oxide ; Magnetic Resonance Imaging ; methods ; Magnetite Nanoparticles ; Male ; Mesenchymal Stem Cell Transplantation ; Rats ; Rats, Sprague-Dawley ; Staining and Labeling ; methods ; Stroke ; pathology ; surgery

Adult ; Aged ; Contrast Media ; Dextrans ; Female ; Ferrosoferric Oxide ; Focal Nodular Hyperplasia ; diagnosis ; pathology ; Humans ; Image Enhancement ; Iron ; Liver Cirrhosis ; diagnosis ; pathology ; Liver Neoplasms ; diagnosis ; pathology ; Magnetic Resonance Imaging ; methods ; Magnetite Nanoparticles ; Male ; Middle Aged ; Oxides