Given the complexity of biological samples and the trace nature of target materials in forensic trace analysis, a simple and effective method is needed to obtain sufficient target materials from complex substrates. Magnetic nanoparticles (MNPs) have shown a wide range of application value in many research fields, such as biomedicine, drug delivery and separation, due to their unique superparamagnetic properties, stable physical and chemical properties, biocompatibility, small size, high specific surface area and other characteristics. To apply MNPs in the pretreatment of forensic materials, maximize the extraction rate of the target materials, and minimize interference factors to meet the requirements of trace analysis of the target materials, this paper reviews the application of MNPs in the fields of forensic toxicological analysis, environmental forensic science, trace evidence analysis and criminal investigation in recent years, and provides research ideas for the application of MNPs in forensic trace analysis.
Magnetite Nanoparticles/chemistry* ; Forensic Medicine ; Forensic Sciences ; Forensic Toxicology

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

In this study, we investigated the pharmacokinetics parameters of SPIO-shRNA dual functional molecular probe and observed the main organ distribution by MRI in vivo. Eighteen New Zealand white rabbits were randomly divided into three groups and injected intravenously with different doses of SPIO-shRNA molecular probe, respectively. The blood samples were collected to analyze the pharmacokinetic parameters by measuring the iron content at 30 minutes before and after the injection. Twenty-four Kun Ming (KM) mice were randomly divided into 4 groups: the control group was injected intravenously with physiological saline 200 µL per mouse via the tail vein, the other 3 groups were injected intravenously with different doses of SPIO-shRNA molecular probe. MRI observation was performed in 24 hours, and the liver, spleen, kidney, brain and muscle were collected for iron quantification with Prussian blue staining to determine distribution of the SPIO-shRNA molecular probe in the main organ in vivo. Our results suggest that the molecular probe blood half-life is more than 3 hours. The data of MRI suggest the probe was distributed in liver and spleen, and the MRI signal was reduced with the increase in probe's doses (P < 0.05). The results of Prussian blue staining confirmed the results of MRI. Most of the probe could escape the phagocytosis of mononuclear phagocyte system. Our data provide the pharmacokinetic and distribution of SPIO-shRNA molecular probe in organs. Meanwhile, it suggests the choice of the time and dose of probe for MR imaging of tumor in vivo.
Animals ; Half-Life ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; Mice ; Molecular Probes ; pharmacokinetics ; RNA, Small Interfering ; chemistry ; Rabbits

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

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 evaluate the role of 2-deoxy-D-glucose (2-DG) modified supermagnetic iron oxide nanoparticles (SPIO) (γ-Fe2O3@DMSA-DG NPs) in tumor detection as a magnetic resonance imaging (MRI) contrast agent.

METHODSγ-Fe2O3@DMSA-DG NPs was prepared. The degree of A549 cells targeted absorption of γ-Fe2O3@DMSA-DG NPs was detected by Prussian blue staining, colorimetric assay, T2W and multi-echo sequence MRI. γ-Fe2O3@DMSA NPs was used as a control agent, and free D-glucose as a competitive inhibitor. Human lung adenocarcinoma A549 xenograft tumor was prepared in nude mice. Sterile aqueous suspension of γ-Fe2O3@DMSA NPs or γ-Fe2O3@DMSA-DG NPs was injected into the tail vein of nude mice. Before and 6, 12, 24, 48 h after injection, MRI imaging of the mice was performed. T2 signal intensity of the tumor, brain, liver and thigh skeletal muscles, and T2 values of the tumors were measured.

RESULTSThe average diameter of the particles was about 10 nm, and there were no significant differences between the diameters of γ-Fe2O3@DMSA NPs and γ- Fe2O3@DMSA-DG NPs. The IR spectra showed the C-N retractable vibration peak at γ-Fe2O3@DMSA-DG NPs surface, indicating that 2-DG was conjugated to the γ-Fe2O3@DMSA NPs. The Prussian blue staining, colorimetric assay, MRI T2 signal intensity and T2 values revealed that γ-Fe2O3@DMSA-DG NPs were significantly more absorbed by A549 cells at growth peak than γ-Fe2O3@DMSA NPs, and the absorption of γ-Fe2O3@DMSA-DG NP was inhibited by free D-glucose. The results of in vivo examination showed that before and at 6, 12, 24, 48 h after injection of γ-Fe2O3@DMSA-DG NPs, the mean T2 signal intensities of the tumors were (326.00 ± 16.26)s, (276.40 ± 5.13)s, (268.40 ± 30.58)s, (240.40 ± 25.93)s, (262.20 ± 30.04)s, respectively, and the T2 values of the tumors were (735.80 ± 20.93) ms, (645.80 ± 69.58) ms, (615.00 ± 124.61) ms, (570.60 ± 67.78) ms, and (537.80 ± 105.29) ms, respectively. However, before and at 6, 12, 24, 48 h after injection of γ-Fe2O3@DMSA NPs, the mean T2 signal intensities of the tumors were (335.60 ± 4.93)s, (290.80 ± 5.93)s, (273.40 ± 15.08)s, (327.40 ± 16.65)s, and (313.20 ± 20.45)s, respectively, and T2 values were (686.00 ± 21.44)ms, (617.80 ± 69.93)ms, (645.20 ± 85.89)ms, (669.40 ± 13.72)ms, and (608.80 ± 61.90)ms, respectively. The T2 signal intensity and T2 value of the tumors were not declined generally after injection. The liver T2 signal intensity was decreased after injection of both γ-Fe2O3@DMSA-DG NPs and γ-Fe2O3@DMSA NPs, and T2 signal intensity of the brain and muscle did not show significant changes.

CONCLUSIONSγ-Fe2O3@DMSA-DG NPs has an ability to target glucose receptors overexpressed in tumors, and may serve as a MRI contrast agent for tumor detection.

Adenocarcinoma ; diagnosis ; metabolism ; pathology ; Animals ; Cell Line, Tumor ; Colorimetry ; Contrast Media ; chemistry ; pharmacokinetics ; Deoxyglucose ; chemistry ; pharmacokinetics ; Ferric Compounds ; chemistry ; pharmacokinetics ; Humans ; Image Enhancement ; Lung Neoplasms ; diagnosis ; metabolism ; pathology ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Particle Size

This study aimed to characterize and magnetic resonance imaging (MRI) track the mesenchymal stem cells labeled with polylysine-coated superparamagnetic iron oxide (PLL-SPIO). Rat bone marrow derived mesenchymal stem cells (rMSCs) were labeled with 25, 50 and 100 microg/mL PLL-SPIO for 24 hours. The labeling efficiency was assessed by iron content, Prussian blue staining, electron microscopy and in vitro MR imaging. The labeled cells were also analyzed for cytotoxicity and differentiation potential. Electron microscopic observations and Prussian blue staining revealed that 75% -100% of cells were labeled with iron particles. PLL-SPIO did not show any cytotoxicity up to 100 microg/mL concentration. Both 25 microg/mL and 50 microg/mL PLL-SPIO labeled stem cells did not exhibit any significant alterations in the adipo/osteo/chondrogenic differentiation potential compared to unlabeled control cells. The lower concentration of 25 microg/mL iron labeled cells emitted an obvious dark signal in T1W, T2WI and T2 * WI MR image. The novel PLL-SPIO enables to label and track rMSCs for in vitro MRI without cellular alteration. Therefore PLL-SPIO may potentially become a better MR contrast agent especially in tracking the transplanted stem cells and other cells without compromising cell functional quality.
Animals ; Bone Marrow Cells ; Cell Differentiation ; Dextrans ; chemistry ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; chemistry ; Mesenchymal Stromal Cells ; cytology ; Polylysine ; chemistry ; Rats ; Staining and Labeling

OBJECTIVE: To synthesize mesoporous silica-core-shell magnetic nanoparticles (MNPs) encapsulated by liposomes (Lipo [MNP@m-SiO2]) in order to enhance their stability, allow them to be used in any buffer solution, and to produce trastuzumab-conjugated (Lipo[MNP@m-SiO2]-Her2Ab) nanoparticles to be utilized in vitro for the targeting of breast cancer. MATERIALS AND METHODS: The physiochemical characteristics of Lipo[MNP@m-SiO2] were assessed in terms of size, morphological features, and in vitro safety. The multimodal imaging properties of the organic dye incorporated into Lipo[MNP@m-SiO2] were assessed with both in vitro fluorescence and MR imaging. The specific targeting ability of trastuzumab (Her2/neu antibody, Herceptin(R))-conjugated Lipo[MNP@m-SiO2] for Her2/neu-positive breast cancer cells was also evaluated with fluorescence and MR imaging. RESULTS: We obtained uniformly-sized and evenly distributed Lipo[MNP@m-SiO2] that demonstrated biological stability, while not disrupting cell viability. Her2/neu-positive breast cancer cell targeting by trastuzumab-conjugated Lipo[MNP@m-SiO2] was observed by in vitro fluorescence and MR imaging. CONCLUSION: Trastuzumab-conjugated Lipo[MNP@m-SiO2] is a potential treatment tool for targeted drug delivery in Her2/neu-positive breast cancer.
3T3 Cells ; Animals ; Antibodies, Monoclonal, Humanized/*administration & dosage ; Antineoplastic Agents/*administration & dosage ; Breast Neoplasms/chemistry/*drug therapy ; Cell Line, Tumor ; Drug Delivery Systems/methods ; Female ; Ferric Compounds/chemistry ; Humans ; Liposomes ; Magnetite Nanoparticles/administration & dosage/*chemistry ; Mice ; Molecular Targeted Therapy/methods ; Nanoconjugates/administration & dosage/*chemistry ; Nanoparticles/chemistry ; *Receptor, erbB-2/immunology ; Silicon Dioxide/administration & dosage/*chemical synthesis/chemistry

OBJECTIVETo construct angiogenesis-specific RGD10-NGR9 dual-targeting superparamagnetic iron oxide nanoparticles, and to evaluate its magnetic resonamce imaging (MRI) features in nude mice and potential diagnostic value in tumor MRI.

METHODSDual-targeting peptides RGD10-NGR9 were designed and synthesized. Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles were synthesized by chemical co-precipitation method and the surface was modified to be hydrophilic by coating with dextran. The dual-targeting peptides RGD10-NGR9 were conjugated to USPIO. Cell binding affinity and up-taking ability of the dual-targeting USPIO nanoparticles to integrin ανβ3-APN positive cells were subsequently tested by Prussian blue staining and phenanthroline colorimetry in vitro. The RGD10-NGR9 conjugated with USPIO was injected intravenously into xenograft mice, which were scanned by MRI at predetermined time points. The MRI and contrast-to-noise ratio (CNR) values were calculated to evaluate the ability of dual-targeting USPIO as a potential contrast agent in nude mice.

RESULTSP-CLN-Dextran-USPIO nanoparticles with stable physical properties were successfully constructed. The average diameter of Fe3O4 nanoparticles was 8-10 nm, that of Dextran-USPIO was about 20 nm and P-CLN-Dextran-USPIO had an average diameter about 30 nm. The in vitro studies showed a better specificity of dual-targeting USPIO nanoparticles on proliferating human umbilical vein endothelia cells (HUVEC). In vivo, RGD10-NGR9-USPIO showed a significantly reduced contrast in signal intensity and 2.83-times increased the CNR in the tumor MRI in xenograft mice.

CONCLUSIONThis novel synthesized RGD10-NGR9 dual-targeting USPIO is with better specific affinity in vitro and in vivo, and might be used as a molecular contrast agent for tumor angiogenesis MRI.

Adenocarcinoma ; diagnosis ; metabolism ; pathology ; Aminopeptidases ; analysis ; Animals ; Cell Line, Tumor ; Cells, Cultured ; Contrast Media ; chemistry ; Dextrans ; chemistry ; Ferrosoferric Oxide ; metabolism ; Human Umbilical Vein Endothelial Cells ; cytology ; metabolism ; Humans ; Integrin alphaVbeta3 ; analysis ; Lung Neoplasms ; diagnosis ; metabolism ; pathology ; Magnetic Resonance Imaging ; Magnetite Nanoparticles ; chemistry ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Oligopeptides ; chemistry ; Particle Size ; Signal-To-Noise Ratio

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