Synthesis and evaluation of toxicity and antimicrobial activity of rifampicin associated with iron oxide nanoparticles

Rifampicin has broad-spectrum antimicrobial activity, but it can cause nephrotoxic and hepatotoxic damage because high doses are required. Nanosystems emerge as a perspective to improve the transport systems of this drug. In this work, iron oxide nanoparticles were synthesised, functionalized with lauric acid, and rifampicin was incorporated into the nanosystem. The samples were characterized by spectroscopic techniques: electronics in the visible ultraviolet region (UV-vis), vibrational absorption in the infrared region (IR), X-ray diffractometry (XRD), and dynamic light scattering (DSL). The toxicity of the nanocompounds and the antimicrobial activity against Staphylococcus aureus ATCC 25923 were studied by the Artemia salina lethality and disc diffusion techniques, respectively. As a result, IR analysis showed characteristic vibrations of laurate and rifampicin on the surface of the nanosystem. The presence of magnetic iron oxide was confirmed by XRD and the mean diameter of the crystallites was 8.37 nm. The hydrodynamic diameter of rifampicin associated with the nanosystem was 402 nm and that of the nanosystem without rifampicin was 57 nm. The compounds did not show toxicity to Artemia salina and the in vitro antimicrobial activity against Staphylococcus aureus was slightly decreased when rifampicin was associated with the nanosystem. In general terms, the results showed that iron oxide nanoparticles showed no toxicity and reduced the toxicity of rifampicin by 41.54% when carried compared to free rifampicin. Therefore, magnetic iron oxide nanoparticles may have the potential to act as a platform for associated drugs.

Precise assembly of inside-out cell membrane camouflaged nanoparticles via bioorthogonal reactions for improving drug leads capturing

Cell membrane camouflaged nanoparticles have been widely used in the field of drug leads discovery attribute to their unique biointerface targeting function. However, random orientation of cell membrane coating does not guarantee effective and appropriate binding of drugs to specific sites, especially when applied to intracellular regions of transmembrane proteins. Bioorthogonal reactions have been rapidly developed as a specific and reliable method for cell membrane functionalization without disturbing living biosystem. Herein, inside-out cell membrane camouflaged magnetic nanoparticles (IOCMMNPs) were accurately constructed via bioorthogonal reactions to screen small molecule inhibitors targeting intracellular tyrosine kinase domain of vascular endothelial growth factor recptor-2. Azide functionalized cell membrane acted as a platform for specific covalently coupling with alkynyl functionalized magnetic Fe3O4 nanoparticles to prepare IOCMMNPs. The inside-out orientation of cell membrane was successfully verified by immunogold staining and sialic acid quantification assay. Ultimately, two compounds, senkyunolide A and ligustilidel, were successfully captured, and their potential antiproliferative activities were further testified by pharmacological experiments. It is anticipated that the proposed inside-out cell membrane coating strategy endows tremendous versatility for engineering cell membrane camouflaged nanoparticles and promotes the development of drug leads discovery platforms.

Gene expression and apoptosis response in hepatocellular carcinoma cells induced by biocompatible polymer/magnetic nanoparticles containing 5-fluorouracil

BACKGROUND: Super-paramagnetic iron oxide nanoparticles (SPION) contain a chemotherapeutic drug and are regarded as a promising technique for improving targeted delivery into cancer cells. RESULTS: In this study, the fabrication of 5-fluorouracil (5-FU) was investigated with loaded Dextran (DEXSPION) using the co-precipitation technique and conjugated by folate (FA). These nanoparticles (NPs) were employed as carriers and anticancer compounds against liver cancer cells in vitro. Structural, magnetic, morphological characterization, size, and drug loading activities of the obtained FA-DEX-5-FUSPION NPs were checked using FTIR, VSM, FESEM, TEM, DLS, and zeta potential techniques. The cellular toxicity effect of FA-DEX-5-FU-SPION NPs was evaluated using the MTT test on liver cancer (SNU-423) and healthy cells (LO2). Furthermore, the apoptosis measurement and the expression levels of NF-1, Her-2/neu, c-Raf-1, and Wnt-1 genes were evaluated post-treatment using flow cytometry and RT-PCR, respectively. The obtained NPs were spherical with a suitable dispersity without noticeable aggregation. The size of the NPs, polydispersity, and zeta were 74 ± 13 nm, 0.080 and 45 mV, respectively. The results of the encapsulation efficiency of the nano-compound showed highly colloidal stability and proper drug maintenance. The results indicated that FA-DEX-5-FU-SPION demonstrated a sustained release profile of 5-FU in both phosphate and citrate buffer solutions separately, with higher cytotoxicity against SNU-423 cells than against other cells types. These findings suggest that FA-DEX-SPION NPs exert synergistic effects for targeting intracellular delivery of 5-FU, apoptosis induction, and gene expression stimulation. CONCLUSIONS: The findings proved that FA-DEX-5-FU-SPION presented remarkable antitumor properties; no adverse subsequences were revealed against normal cells.

LXYL-P1-2 immobilized on magnetic nanoparticles and its potential application in paclitaxel production

BACKGROUND: LXYL-P1-2 is the first reported glycoside hydrolase that can catalyze the transformation of 7-b-xylosyl-10-deacetyltaxol (XDT) to 10-deacetyltaxol (DT) by removing the D-xylosyl group at the C7 position. Successful synthesis of paclitaxel by one-pot method combining the LXYL-P1-2 and 10- deacetylbaccatin III-10-b-O-acetyltransferase (DBAT) using XDT as a precursor, making LXYL-P1-2 a highly promising enzyme for the industrial production of paclitaxel. The aim of this study was to investigate the catalytic potential of LXYL-P1-2 stabilized on magnetic nanoparticles, the surface of which was modified by Ni2+-immobilized cross-linked Fe3O4@Histidine. RESULTS: The diameter of matrix was 20­40 nm. The Km value of the immobilized LXYL-P1-2 catalyzing XDT (0.145 mM) was lower than that of the free enzyme (0.452 mM), and the kcat/Km value of immobilized enzyme (12.952 mM s 1 ) was higher than the free form (8.622 mM s 1 ). The immobilized form maintained 50% of its original activity after 15 cycles of reuse. In addition, the stability of immobilized LXYL-P1-2, maintained 84.67% of its initial activity, improved in comparison with free form after 30 d storage at 4 C. CONCLUSIONS: This investigation not only provides an effective procedure for biocatalytic production of DT, but also gives an insight into the application of magnetic material immobilization technology.

Effects of Fluorodeoxyglucose Conjugated and Unconjugated Iron Oxide Magnetic Nanoparticles on Macrophages: a Pilot Study

Abstract The effects of fluorodeoxyglucose conjugated iron oxide magnetic nanoparticles (FDGMNP) on macrophages are presented using a yeast substrate. Iron oxide magnetic nanoparticles (MNP) were synthesized by partially reducing FeCl3, then conjugated with (3-aminopropyl) triethoxysilane (APTES) after silication with tetraethyl orthosilicate. Silanated MMP nanoparticles were combined with fluorodeoxyglucose (FDG). Fluorodeoxyglucose iron oxide magnetic nanoparticles (FDGMNP) and its unconjugated control (MNP) were added (1mL) to the cells from the murine macrophage-like, Abelson murine leukemia virus transformed cell line RAW 264.7 (American Type Culture Collection number TIB-71) cell culture wells at different concentrations from 90-3.6 μg/mL. Cells were placed on the magnet plate for 30 min before incubating at 37°C, 5% CO2 overnight. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium) assay was performed to measure cell viability. Our results demonstrate that iron based nanoparticles can be linked to macrophages (elements of the immune system that attack bacteria) without the function of the macrophages being affected, ie no detrimental effects to the macrophages were evident in these experiments. We conclude that neither FDGMNP nor MNP had a detrimental effect on macrophage function.

Study on the thermal field distribution of cholangiocarcinoma model by magnetic fluid hyperthermia / 生物医学工程学杂志

Cholangiocarcinoma is a highly malignant tumor. It is not sensitive to radiotherapy and chemotherapy and has a poor prognosis. At present, there is no effective treatment. As a new method for treating cancer, magnetic fluid hyperthermia has been clinically applied to a variety of cancers in recent years. This article introduces it to the cholangiocarcinoma model and systematically studies the effect of magnetic fluid hyperthermia on cholangiocarcinoma. Starting from the theory of magnetic fluid heating, the electromagnetic and heat transfer models were constructed in the finite element simulation software COMSOL using the Pennes biological heat transfer equation. The Helmholtz coil was used as an alternating magnetic field generating device. The relationship between the magnetic fluid-related properties and the heating power was analyzed according to Rosensweig's theory. After the multiphysics coupling simulation was performed, the electromagnetic field and thermal field distribution in the hyperthermia region were obtained. The results showed that the magnetic field distribution in the treatment area was uniform, and the thermal field distribution met the requirements of hyperthermia. After the magnetic fluid injection, the cholangiocarcinoma tissue warmed up rapidly, and the temperature of tumor tissues could reach above 42 °C, but the surrounding healthy tissues did not heat up significantly. At the same time, it was verified that the large blood vessels around the bile duct, the overflow of the magnetic fluid, and the eddy current heat had little effect on thermotherapy. The results of this article can provide a reference for the clinical application of magnetic fluid hyperthermia for cholangiocarcinoma.

Design and preparation of a new multi-targeted drug delivery system using multifunctional nanoparticles for co-delivery of siRNA and paclitaxel / 药物分析学报

Drug resistance is a great challenge in cancer therapy using chemotherapeutic agents.Administration of these drugs with siRNA is an efficacious strategy in this battle.Here,the present study tried to incor-porate siRNA and paclitaxel(PTX)simultaneously into a novel nanocarrier.The selectivity of carrier to target cancer tissues was optimized through conjugation of folic acid(FA)and glucose(Glu)onto its surface.The structure of nanocarrier was formed from ternary magnetic copolymers based on FeCo-polyethyleneimine(FeCo-PEI)nanoparticles and polylactic acid-polyethylene glycol(PLA-PEG)gene delivery system.Biocompatibility of FeCo-PEI-PLA-PEG-FA(NPsA),FeCo-PEI-PLA-PEG-Glu(NPsB)and FeCo-PEI-PLA-PEG-FA/Glu(NPsAB)nanoparticles and also influence of PTX-loaded nanoparticles on in vitro cytotoxicity were examined using MTT assay.Besides,siRNA-FAM internalization was investi-gated by fluorescence microscopy.The results showed the blank nanoparticles were significantly less cytotoxic at various concentrations.Meanwhile,siRNA-FAM/PTX encapsulated nanoparticles exhibited significant anticancer activity against MCF-7 and BT-474cell lines.NPsAB/siRNA/PTX nanoparticles showed greater effects on MCF-7 and BT-474 cells viability than NPsA/siRNA/PTX and NPsB/siRNA/PTX.Also,they induced significantly higher anticancer effects on cancer cells compared with NPsA/siRNA/PTX and NPsB/siRNA/PTX due to their multi-targeted properties using FA and Glu.We concluded that NPsAB nanoparticles have a great potential for co-delivery of both drugs and genes for use in gene therapy and chemotherapy.

Detection method of nonlinear magnetized harmonic signal of medical magnetic nanoparticles / 生物医学工程学杂志

Medical magnetic nanoparticles are nano-medical materials with superparamagnetism, which can be collected in the tumor tissue through blood circulation, and magnetic particle imaging technology can be used to visualize the concentration of magnetic nanoparticles in the living body to achieve the purpose of tumor imaging. Based on the nonlinear magnetization characteristics of magnetic particles and the frequency characteristics of their magnetization, a differential detection method for the third harmonic of magnetic particle detection signals is proposed. It was modeled and analyzed, to study the nonlinear magnetization response characteristics of magnetic particles under alternating field, and the spectral characteristics of magnetic particle signals. At the same time, the relationship between each harmonic and the amount of medical magnetic nanoparticle samples was studied. On this basis, a signal detection experimental system was built to analyze the spectral characteristics and power spectral density of the detected signal, and to study the relationship between the signal and the excitation frequency. The signal detection experiment was carried out by the above method. The experimental results showed that under the alternating excitation field, the medical magnetic nanoparticles would generate a spike signal higher than the background sensing signal, and the magnetic particle signal existed in the odd harmonics of the detected signal spectrum. And the spectral energy was concentrated at the third harmonic, that is, the third harmonic magnetic particle signal detection that meets the medical detection requirement could be realized. In addition, the relationship between each harmonic and the particle sample volume had a positive growth relationship, and the detected medical magnetic nanoparticle sample volume could be determined according to the relationship. At the same time, the selection of the excitation frequency was limited by the sensitivity of the system, and the detection peak of the third harmonic of the detection signal was reached at the excitation frequency of 1 kHz. It provides theoretical and technical support for the detection of medical magnetic nanoparticle imaging signals in magnetic particle imaging research.

Preparation and in vitro characterization of monoclonal antibody ranibizumab conjugated magnetic nanoparticles for ocular drug delivery

Gold coated magnetite nanoparticles were prepared and coated with ranibizumab as an ocular drug delivery system. The surface morphologies of the nanoparticles were determined by Scanning Electron Microscopy (SEM). The size and surface charge were determined by using the dynamic light scattering (DLS) technique. Crystallographic properties of the gold coated Fe3O4 nanoparticles were recorded on X-ray diffractometer (XRD) the XRD pattern of nanoparticlees were shown to have uniqe Fe3O4 and gold peaks. Conjugation of ranibizumab onto nanoparticles was achieved using the physical adsorption method. The amount of ranibizumab on the surface of the nanoparticles was determined by thermogravimetric analysis (TGA). In the in vitro release studies performed using UV spectroscopy; it was found that almost 60% of antibodies were released within the first 30 minutes. Antibody activity after release studies was also proved with ELISA. Non-toxicity of gold coated Fe3O4 particles were proved with MTT. Results of the studies, showed that the antibody conjugated magnetic nanoparticle system could be a potential treatment system for ocular diseases.

Preparation and Characterization of Glycyrrhetinic Acid-modified Docetaxel Magnetic Nanoparticles / 中国药房

OBJECTIVE：To pre pare Glycyrrhetinic acid-modified docetaxel magnetic nanoparticles （GA-DTX-NGO/IONP- NPs），and to evaluate its physicochemical properties. METHODS ：Magnetic nano graphene oxide （NGO/IONP）was chosen as the anti-tumor drug carrier ，docetaxel（DTX）as the model drug and glycyrrhetinic acid （GA）as the target molecule. Firstly ，NGO/ IONP was synthesized by hydrothermal method and GA-CS was synthesized by amidation reaction. Fourier IR spectrometer ，DSC and vibration sample magnetic measuring instrument were used to characterize NGO/IONP and GA-CS. GA-DTX-NGO/IONP-NPs Huperzine A in the nicotinic acetylcholine receptor alleviates Aβ -induced 1-42 treatment of Alzheimer ’s disease and vascular dementia ：a neurotoxicity via downregulation of p 38 and JNK MAPK meta-analysis[J]. Evid Based Complement Alternat Med ， signaling pathways[J]. Neurochem Int ，2018. DOI ：10. 2014. DOI ：10.1155/2014/363985. 1016/j.neuint.2018.09.005. were prepared by the ion gelation method. TEM and particle size analyzer were used to observe and determine the morphology ， particle size and Zeta potential of GA-DTX-NGO/IONP-NPs ；the ultrafiltration-centrifugation method was used to determine encapsulation efficiency and drug loading amount ；the magnetic properties were investigated by investigating the state with or without external magnetic field ；the photothermal conversion test was carried out with laser irradiation of 808 nm. RESULTS ：NGO/ IONP and GA-CS were successfully synthesized ，and NGO/IONP exhibited superparamagnetism characteristics. GA-DTX-NGO/ IONP-NPs were spherical under TEM ，the particle size was （262.8±4.23）nm and the Zeta potential was （13.6±1.51）mV. The encapsulation rate and drug loading amount were （94.29±0.50）％ and（17.12±0.12）％，respectively. GA-DTX-NGO/IONP-NPs were black in appearance and evenly dispersed. Under the external magnetic field ，the magnetic nanoparticles could move directionally，showing good magnetic properties. GA-DTX-NGO/IONP-NPs showed a good concentration- and time-dependent photothermal conversion effect under 808 nm laser irradiation. CONCLUSIONS ：GA-DTX-NGO/IONP-NPs are successfully prepared. This study could provide some theoretical basis for the combined treatment of magnetic heating-chemotherapy for liver tumors.

Simulation research on magnetoacoustic B-scan imaging of magnetic nanoparticles / 生物医学工程学杂志

As drug carriers, magnetic nanoparticles can specifically bind to tumors and have the potential for targeted therapy. It is of great significance to explore non-invasive imaging methods that can detect the distribution of magnetic nanoparticles. Based on the mechanism that magnetic nanoparticles can generate ultrasonic waves through the pulsed magnetic field excitation, the sound pressure wave equation containing the concentration information of magnetic nanoparticles was derived. Using the finite element method and the analytical solution, the consistent transient pulsed magnetic field was obtained. A three-dimensional simulation model was constructed for the coupling calculation of electromagnetic field and sound field. The simulation results verified that the sound pressure waveform at the detection point reflected the position of magnetic nanoparticles in biological tissue. Using the sound pressure data detected by the ultrasonic transducer, the B-scan imaging of the magnetic nanoparticles was achieved. The maximum error of the target area position was 1.56%, and the magnetic nanoparticles regions with different concentrations were distinguished by comparing the amplitude of the boundary signals in the image. Studies in this paper indicate that B-scan imaging can quickly and accurately obtain the dimensional and positional information of the target region and is expected to be used for the detection of magnetic nanoparticles in targeted therapy.

Development of synthesis method of magnetic nanoparticles modified by oleic acid and chitosan as a candidate for drug delivery agent

In this study, magnetic nanoparticles (MNPs) coated with a combination of oleic acid and chitosan were synthesizedby ex situ and in situ coprecipitation methods. Morphology and particle size, crystal structure and crystallite size,chemical structure, and magnetic saturation were characterized by scanning electron microscope (SEM), X-raydiffraction (XRD), Fourrier transform infrared, and vibrating sample magnetometer (VSM), respectively. SEMimages showed that better spherical morphology is obtained by ex situ co-precipitation method. The XRD patternidentified that nanoparticles containing Fe3O4 and γ-Fe2O3. The particles and crystallite size of the nanoparticles tendedto decrease with increasing oleic acid to the optimum composition. Further functionalization through the chitosanaddition (crosslinked by Tripolyphosphate/sulfate) is contributed to the hydrophilicity properties of nanoparticles.Through VSM analysis, MNPs-oleic acid-chitosan showed superparamagnetic behavior with magnetic saturationreaching 32.63 emu/g. There was a linear correlation between magnetic saturation and Fe3O4 content of nanoparticles.Drug loading and drug release were carried out by using Doxorubicin. These nanoparticles showed a high drug loadingefficiency with lower chitosan composition. Loading efficiency of Doxorubicin is related to the conjugation withcarboxylic groups and hydrophobic sites from oleic acid and MNPs

Method for active ingredients' in vivo target identification of traditional Chinese medicine using magnetic nanoparticles / 中国中药杂志

Target identification is an important prerequisite for the study of medicine action mechanism. Currently,drug target identification is mostly based on various cell models in vitro. However,the growth microenvironment,nutrition metabolism,biological properties as well as functions are quite different between in vitro cell culture and physiological environment in vivo; wherefore,it is a challenging scientific issue to establish an effective method for identifying drug targets in vivo condition. In this study,we successfully prepared a kind of magnetic nanoparticles( MNPs) which can be chemically modified by the hydroxyl structure of natural bioactive compound echinacoside( ECH) via the epoxy group label on the surface of MNPs. Therefore,organ-selective and recoverable nanoscale target-recognizing particles were prepared. We then intravenously injected the ECH-binding MNPs into rats and distributed them to specific organs in vivo. After cell endocytosis,ECH-binding MNPs captured target proteins in situ for further analysis. Based on this method,we discovered several potential target proteins in the spleen lysates for ECH,and preliminarily clarified the immuno-regulation mechanism of ECH. Collectively,our strategy developed a proof-of-concept technology using nanoparticles for in vivo target identification,and also provided a feasible approach for drug target prediction and pharmacological mechanism exploration.

Advances in the application of iron oxide based magnetic nanoparticles in cancer ther-anostics / 中国肿瘤临床

Cancer theranostics has attracted increasing attention in the area of nanooncology, where the therapeutic drugs and diag-nostic imaging are integrated into a multifunctional nanoplatform. A theranostic nanoparticle can deliver therapeutic drugs and imag-ing agents simultaneously. Iron oxide based magnetic nanoparticles (MNPs) are one of the most typical theranostic nanoparticles and have many excellent properties, such as biosafety, superparamagnetism, and tunable surface modifications and functionalizations. Moreover, they have drug loading capacity along with the distinctive properties of T2 weighted magnetic resonance imaging (T2W MRI), magnetic targeting, and magnetic hyperthermia. Presently, iron oxide based MNPs are being widely used in cancer theranostic research. This paper introduces the general structure of iron oxide based MNPs and reviews their applications in cancer dual/multiple modal imaging (T2W MRI combining T1W MRI, CT, optical imaging, PET/SPECT, and ultrasound) and therapy (chemotherapy, photody-namic therapy, photothermal therapy, and magnetic hyperthermia).

Effects of magnetic thermotherapy mediated by magnetic nanocomposite PEG-APTESMNP on proliferation of liver cancer cells / 南方医科大学学报

OBJECTIVE@#To observe the inhibitory effects of PEG-APTES-MNP magnetic heating on liver cancer cells.@*METHODS@#The magnetic nanoparticle complex PEG-APTES-MNP was synthesized and its physiochemical properties and biocompatibility were characterized. HepG2 cells were incubated with the PEG-APTES-MNP nanoparticles for magnetic heating or nanoparticle therapy. Prussian blue staining was used to detect the uptake efficiency of the magnetic nanoparticles by HepG2 cells. MTT assay and flow cytometry were used to evaluate the inhibitory effect of the nanoparticles on HepG2 cells, and laser scanning confocal microscopy was used to detect the production of reactive oxygen species (ROS) in the cells. Fifteen nude mice bearing HepG2 cell xenografts were randomized equally into PEG-APTES-MNP injection group (with nanocomposite injection only), PEG-APTES-MNP magnetic heating group and control group (with PBS injection), and the tumor growth were observed in the mice after the treatments.@*RESULTS@#The synthesized PEG-APTES-MNP nanoparticles showed good physicochemical properties and biocompatibility. Incubation of HepG2 with the nanoparticles resulted in significantly increased ROS production, obvious inhibition of the cell growth through the synergetic effects of magnetic heating ( < 0.05), and significantly enhanced cell apoptosis. In the tumor-bearing nude mice, the nanoparticles strongly inhibited the tumor growth by magnetic heating ( < 0.05).@*CONCLUSIONS@#The magnetic nanocomposite PEG-APTES-MNP has good physicochemical properties and bioavailability and can strongly inhibit the growth of liver cancer cells both and in nude mice through magnetic heating, demonstrating its potential as a candidate nanomedicine for liver cancer treatment.

Preferential adsorption of flavonoids and organic acids by amino-modified Fe3O4 nanoparticles (MNP-NH2) / 中草药

Objective To synthesize amino-modified Fe3O4 nanoparticles (MNP-NH2) and study the adsorption of flavonoids and organic acids by MNP-NH2. Methods MNP-NH2 were synthesized and characterized by transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating sample magnetometer analysis; The adsorption rule of MNP-NH2 was discussed by studying the adsorption properties of 12 monomers. The adsorption properties of MNP-NH2 were assessed under conditions of different ultrasonic time, temperature, ionic strength, and pH. The final elution conditions were determined by L9(34) orthogonal test and the recycling performance was also considered. Results MNP-NH2 synthesized in this study have stable structure, uniform distribution, and good magnetic properties. Adsorption of 12 monomers by MNP-NH2 showed that the mechanism of adsorption was related to the number of ortho-phenolic hydroxyl groups. Ions concentration and temperature had little effect on adsorption for different compounds except pH. The optimized adsorption conditions were extraction for 40 min at 30 ℃ and the final elution conditions were determined to be 5 mL of 20% glacialacetic acid (methanol-water 60∶40) and ultrasonication for 40 min. Conclusion MNP-NH2 can be utilized to extract the effective components of Lonicerae Japonicae Flos and maintain a high adsorption rate of flavonoids. Moreover, MNP-NH2 had great recycling and reproducibility, providing new ideas for the utilization of extracting chemical compounds from complex traditional Chinese medicine and natural medicines.

Simultaneous determination of steroid drugs in the ointment via magnetic solid phase extraction followed by HPLC-UV / 药物分析学报

The copper-coated iron oxide nanoparticles with core-shell were produced by deposition of a Cu shell on Fe3O4 NPs through reduction of Cu2+ ions in solution using NaBH4. Subsequently, the organosulfur compound, bis-(2,4,4-trimethylpentyl)-dithiophosphinic acid (b-TMP-DTPA), was used to form self-assembled monolayer in order to modify sorbent's surface via covalent bonding between Cu and thiol (-SH) terminal groups. The prepared magnetic nanoparticles were characterized by using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and thermo gravimetric analysis (TGA). Then, the application of this new sorbent was investigated to extract the steroid drugs in ointment samples with the aid of ultrasound.An external magnetic field was applied to collect the magnetic nanoparticles (MNPs). The extracted analytes were desorbed using acetonitrile. The obtained extraction solution was analyzed by HPLC-UV. The main affecting factors on the extraction efficiency including pH, sonication time, amount of sorbent, salt concentration, and desorption conditions were optimized in detail. Under the optimum conditions, good linearity was obtained in the range of 2.5-250.0 μg/ L with reasonable linearity (R2 > 0.99) and the limits of detection (LODs) ranged between 0.5 and 1.0 μg/L (based on S/N = 3). Repeatability (intra-day precision) based on five replicates and preconcentration factors were calculated to be 3.6％-4.7％ and 87116,respectively.Relative recoveries in ointment samples at two spiked levels of the target analytes were obtained in the range of 90.0％-103.2％. The results illustrated that the Fe3O4@Cu@ b-TMP-DTPA NPs have the capability of extraction of steroid drugs from ointment samples.

Tumor Targeting of Fluorescent Magnetic IR780-Fe3 O4 Nanoparticles for Detection of Circulating Tumor Cells / 分析化学

The tumor targeted fluorescent magnetic IR780-Fe3 O4 nanoparticles were prepared for separation and detection of circulating tumor cells ( CTCs ) . These IR780-Fe3 O4 nanoparticles were characterized by electron microscopy, fluorescence spectrometer, and superconducting quantum interferometer. The targeting effect of IR780-Fe3 O4 nanoparticles was analyzed on the tumor and normal cells by confocal microscope and flow cytometry, and the confocal microscope was used to target the location of IR780-Fe3 O4 nanoparticles in MCF-7 cells. The standard curve was drawn and evaluated accorded to the IR780-Fe3 O4 nanoparticles fluorescence intensity of tumor cells after incubation. The results showed that IR780-Fe3 O4 nanoparticles could target a variety of CTCs. Furthermore, cellular localization experiment proved that IR780-Fe3 O4 nanoparticles could target the mitochondria of tumor cells. With the method of coupling magnetic Fe3 O4 nanoparticles, IR780 could well distinguish the tumor and normal cells, which could be used for separating and detecting the CTCs in simulated blood.

Tumor Targeting of Fluorescent Magnetic IR780-Fe3 O4 Nanoparticles for Detection of Circulating Tumor Cells / 分析化学

The tumor targeted fluorescent magnetic IR780-Fe3 O4 nanoparticles were prepared for separation and detection of circulating tumor cells ( CTCs ) . These IR780-Fe3 O4 nanoparticles were characterized by electron microscopy, fluorescence spectrometer, and superconducting quantum interferometer. The targeting effect of IR780-Fe3 O4 nanoparticles was analyzed on the tumor and normal cells by confocal microscope and flow cytometry, and the confocal microscope was used to target the location of IR780-Fe3 O4 nanoparticles in MCF-7 cells. The standard curve was drawn and evaluated accorded to the IR780-Fe3 O4 nanoparticles fluorescence intensity of tumor cells after incubation. The results showed that IR780-Fe3 O4 nanoparticles could target a variety of CTCs. Furthermore, cellular localization experiment proved that IR780-Fe3 O4 nanoparticles could target the mitochondria of tumor cells. With the method of coupling magnetic Fe3 O4 nanoparticles, IR780 could well distinguish the tumor and normal cells, which could be used for separating and detecting the CTCs in simulated blood.

Research progress of static magnetic field targeting drug delivery system in tumor diagnosis and therapy / 国际生物医学工程杂志

Chemotherapy is one of the traditional tumors treatment solutions.Chemotherapy has the feature of tissue non-specificity,which can cause side effects on normal cells while inhibiting tumor cell growth.Magnetic targeting drug delivery system (MTDDS) employs biocompatible and stable magnetic nanoparticles (MNP) as drug carries to transport and accumulate anticancer drugs to the specific tumor tissues under the guidance of external magnetic field.This technology not only improves the efficiency of drug delivery and antitumor activity,but also reduces the drug dosage and side effects.The properties of drug-loaded MNPs and the applied external magnetic field are the main factors that affecting the MNPs targeting to the tumor tissues.The effectiveness of the targeted delivery of the drug-loaded magnetic nanoparticles mainly depends on the form and strength of the magnetic field at the target site.That is,whether there is sufficient strength to attract and retain NMPs,and to promote antitumor drug release at the tumor region.In this paper,the research progress of static magnetic field targeting drug delivery system in tumor diagnosis and therapy was summarized,which can provide some basic information for the relative scientific researches.