156 results about "Superparamagnetic nanoparticle" patented technology

This invention relates generally to NMR systems for in vivo detection of analytes. More particularly, in certain embodiments, the invention relates to systems in which superparamagnetic nanoparticles are exposed to a magnetic field and radio frequency (RF) excitation at or near the Larmor frequency, such that the aggregation and/or disaggregation of the nanoparticles caused by the presence and/or concentration of a given analyte in a biological fluid is detected in vivo from a monitored RF echo response.

Methods and devices for selectively removing from a subject a target cell, pathogen, or virus expressing a binding partner on its surface are presented. In one embodiment, the device contains an excorporeal circuit, which includes, at least, a magnetic filter comprising a magnet and a removable, magnetizable substrate capable of capturing magnetic nanomaterials; and a pump in fluid communication with the magnetic filter, wherein the pump moves fluid through the excorporeal circuit. The magnet is capable of generating a magnetic field sufficient to capture magnetic nanomaterials in the magnetic field. In a preferred embodiment, the target cells are cancer cells and/or cells infected with pathogenic agents. The devices may be designed for extracorporeal or in vivo uses. Functionalized superparamagnetic nanoparticles are either mixed ex vivo with a biological fluid from the patient or injected into the patient. Then the biological fluid, which includes the nanoparticles is transported to the magnetic filter to remove any nanoparticles that are complexed to the target cells, pathogens, or virus, and any free nanoparticles. Optionally, the functionalized nanoparticles contain and deliver a therapeutic agent. In one embodiment, the therapeutic agent is released when the nanoparticle binds to the target cells, pathogens, or virus.

The present invention relates to a poly(organophosphazene)-superparamagnetic nanoparticle complex including a biodegradable and thermosensitive poly(organophosphazene) and a iron oxide (Fe₃O₄, Magnetite)-series ferrite superparamagnetic nanoparticle, a preparation method, and uses of carrying a physiologically-active material, a bio-material and a biomaterial for cancer hyperthermia. The iron oxide is used as a MRI contrast agent for T-₂ and T₂* weighted image, and the poly(organophosphazene) shows a sol-to-gel behavior depending upon the temperature change. The complex is a bound-type where the superparamagnetic ferrite nanoparticle is bonded to phosphazene-based polymer via hydrophobic binding, and a mixed-type where the superparamagnetic ferrite nanoparticle is physically mixed with the phosphazene-based polymer.

Magnetic nanoparticles are provided that have a superparamagnetic core and a nanoporous silica shell surrounding the core. The shell is functionalized with amine or S-nitrosothiol groups both inside and outside the nanopores. A process to provide such nanoparticles involves hydrolyzing tetraethoxysilane (TEOS) in a microemulsion of a superparamagnetic nanoparticle to form a superparamagnetic nanoparticle encapsulated by an incompletely hydrolyzed nanoporous silica shell, and hydrolyzing an amine-containing compound or a thiol-containing compound in situ in the presence of the incompletely hydrolyzed nanoporous silica shell before hydrolysis and densification of the silica shell is complete to functionalize the nanoporous silica shell with amine or thiol groups both inside and outside the nanopores and to maintain nanoporosity of the shell. Such magnetic nanoparticles are useful as carriers for chemical or biological species, particularly for magnetic resonance imaging, optical imaging, targeted drug delivery, cell delivery and magnetic separation applications.

A biomolecular sensor system includes an array of magnetoresistive nanosensors designed for sensing biomolecule-conjugated superparamagnetic nanoparticles. Materials and geometry of each sensor element are designed for optimized sensitivity. The system includes magnetic field generators to apply forces to superparamagnetic nanoparticles for 1) nanoparticle manipulation, 2) sensor magnetic biasing, 3) magnetic pull-off measurement for differentiation against non-specific association, and 4) removal of all particles from the sensor array surface.

The subject of the invention is superparamagnetic nanoparticle probes based on iron oxides, to advantage magnetite or maghemite, with modified surface, coated with mono-, di- or polysaccharides from the group including D-arabinose, D-glucose, D-galactose, D-mannose, lactose, maltose, dextrans and dextrins, or with amino acids or poly(amino acid)s from the group including alanine, glycine, glutamine, asparagine, histidine, arginine, L-lysine, aspartic and glutamic acid or with synthetic polymers based on (meth)acrylic acid and their derivatives selected from the group containing poly(N,N-dimethylacrylamide), poly(N,N-dimethylmethacrylamide), poly(N,N-diethylacrylamide), poly(N,N-diethylmethacrylamide), poly(N-isopropylacrylamide), poly(N-isopropylmethacrylamide), which form a colloid consisting of particles with narrow distribution with polydispersity index smaller than 1.3, the average size of which amounts to 0.5-30 nm, to advantage 1-10 nm, the iron content is 70-99.9 wt. %, to advantage 90 wt. %, the modification agent content 0.1-30 wt. %, to advantage 10 wt. %.

The particles of size smaller than 2 nm with polydispersity index smaller than 1.1 can be obtained by a modified method of preparation.

Superparamagnetic nanoparticle probes according to the invention are prepared by pre-precipitation of colloidal Fe(OH)₃ by the treatment of aqueous 0.1-0.2M solution of Fe(III) salt, to advantage FeCl₃, with less than an equimolar amount of NH₄OH, at 21° C., under sonication, to which a solution of a Fe(II) salt, to advantage FeCl₂, is added in the mole ratio Fe(III)/Fe(II)=2 under sonication and the mixture is poured into five- to tenfold, to advantage eightfold, molar excess of 0.5M NH₄OH. The mixture is left aging for 0-30 min, to advantage 15 min, and then the precipitate is repeatedly, to advantage 7-10 times, magnetically separated and washed with deionized water. Then 1-3 fold amount, to advantage 1.5 fold amount, relative to the amount of magnetite, of 0.1 M aqueous solution of sodium citrate is added and then, dropwise, 1-3 fold amount, to advantage 1.5 fold amount, relative to the amount of magnetite, of 0.7 M aqueous solution of sodium hypochlorite. The precipitate is repeatedly, to advantage 7-10 times, washed with deionized water under the formation of colloidal maghemite to which, after dilution, is added dropwise, to advantage under 5-min sonication, an aqueous solution of a modification agent, in the weight ratio modification agent/iron oxide=0.1-10, to advantage 0.2 for amino acids and poly(amino acid)s and 5 for saccharides.

The particles smaller than 2 nm with polydispersity index smaller than 1.1 are prepared by mixing at 21° C. 1 volume part of 10-60 wt. %, to advantage 50 wt. %, of an aqueous solution of a saccharide, disaccharide or polysaccharide, such as D-arabinose, D-glucose, D-galactose, D-mannose, lactose, maltose, dextran and dextrins, and 1 volume part of aqueous solution of a Fe(II) and Fe(III) salt, to advantage FeCl₂ and FeCl₃, where the molar ratio Fe(III)/Fe(II)=2. A 5-15%, to advantage 7.5%, solution of NH₄OH is added until pH 12 is attained and the mixture is heated at 60° C. for 15 min. The mixture is then sonicated at 350 W for 5 min and then washed for 24 h by dialysis in water using a membrane with molecular weight cut-off 14,000 until pH 7 is reached. The volume of solution is reduced by evaporation so that the final dry matter content is 50-100 mg/ml, to advantage 80 mg per 1 ml.

Superparamagnetic nanoparticle probes according to the invention can be used for labelling cells used in magnetic resonance imaging for monitoring their movement, localization, survival and differentiation especially in detection of pathologies with cell dysfunction and of tissue regeneration and also for labelling and monitoring cells administered for cell therapy purposes, in particular embryonal stem cells, fetal stem cells, stem cells of an adult human including bone marrow stem cells, olfactory glial cells, fat tissue cells, in the recipient organism by magnetic resonance.

The preparation of labelled cells proceeds by adding to the complete culture medium 5-20 μl, to advantage 10 μl, of a colloid containing 0.05-45 mg iron oxide per ml, to advantage 1-5 mg iron oxide per ml of the medium, and culturing the cells for a period of 1-7 days, to advantage for 1-3 days, at 37° C. and 5% of CO₂.

A method for making a composite material with non-spherical reinforcing particles embedded in a matrix, is disclosed. In this method, in a first step magnetic and/or superparamagnetic nanoparticles are attached to the non-spherical reinforcing particles, in a second step the resulting reinforcing particles are introduced into a liquid matrix material and/or a liquid matrix-precursor material, and in a third step the material of the matrix is solidified and/or polymerized and/or cross-linked. In accordance with the proposed invention prior to and/or during solidification and/or polymerization and/or cross-linking of the matrix material or the matrix precursor material, respectively, a magnetic field is applied so as to align the reinforcing particles in the matrix and this alignment is fixed in the matrix during and after the third step, wherein the non-spherical reinforcing particles preferably have a length (l) in one dimension of at least 0.5 μm and wherein the weight ratio of the nano-particles to the non-spherical reinforcing particles is below 0.25.

The invention provides a superparamagnetic nanoparticle Fe3O4@SiO2@PSA modified by the PSA and a preparing method and application of the superparamagnetic nanoparticle Fe3O4@SiO2@PSA modified by the PSA. According to the superparamagnetic nanoparticle Fe3O4@SiO2@PSA modified by the PSA and the preparing method and application of the superparamagnetic nanoparticle Fe3O4@SiO2@PSA modified by the PSA, silylanization is conducted on the surface of superparamagnetic nanoparticle Fe3O4, a silylating reagent with a PSA structure is bonded, and thus a PSA group is introduced. The superparamagnetic nanoparticle Fe3O4@SiO2@PSA modified by the PSA and the preparing method of the superparamagnetic nanoparticle Fe3O4@SiO2@PSA modified by the PSA can be applied to the magnetic solid-phase extraction (M-SPE) field, and the superparamagnetic nanoparticle Fe3O4@SiO2@PSA modified by the PSA can serve as an adsorbent which is frequently used for magnetic solid-phase extraction, be applied to various pesticides such as carbamic acid ester, the organophosphorus pesticide and the herbicide and be used for absorption and extraction of target objects such as sulfonamides, organic acid and saccharides; meanwhile, the functional group of the PSA is a good binary ligand, in this way, the PSA is a good chelation material, can be used for extraction of metal ions and has high practical value and broad application prospect in the aspect of analytical investigation.

Methods of non-invasive imaging of complement-mediated inflammation are provided. Compositions including CR-targeted ultrasmall superparamagnetic nanoparticles or aggregates thereof for use with those methods are also provided.

Heat assisted magnetic recording systems with composite recording films are disclosed. The magnetic recording films include superparamagnetic nanoparticles dispersed in an antiferromagnetic or ferrimagnetic matrix. The matrix provides antiferromagnetic coupling with the superparamagnetic nanoparticles, and minimizes exchange interactions between adjacent nanoparticles.

A method of treating brain injury involving intrathecally administering a composite powder comprising superparamagentic nanoparticle and a therapeutic agent compound, and then magnetically transporting the composite into an injured brain.

The invention provides a superparamagnetic nano-particle and a preparation method thereof, which relates to a magnetic nano-material. The invention provides a superparamagnetic nano-particle with small particle size, narrow particle size distribution, good chemical stability and excellent magnetic properties, and a preparation method thereof. The superparamagnetic nano-particle is a MnFe2O4 nano-particle. The preparation method comprises the steps of dissolving MnCl2.4H2O and FeCl3.6H2O particles in water, obtaining a mixed metal salt solution, bathing, heating and stirring the metal salt solution, adding NaOH aqueous solution to the metal salt solution for reaction, adding oleic acid, continuing reaction, taking out a reaction vessel, adding ethanol to the reaction vessel and obtaining a product. The superparamagnetic nano-particle can be widely applied in the biological field, such as bioseparation, targeted drug release, magnetic resonance imaging, biochip magnetic recording, and the like.

The invention discloses a magnetic fluorescent bifunctional nano biological probe and a preparation method thereof. The invention is characterized by preparing magnetic fluorescent bifunctional nanoparticles which can be used a nano biological probe, wherein each nanoparticle is in a core-shell spherical structure, and the nanoparticles are prepared from hydrophobic superparamagnetic nanoparticles as the core layer and a fluorescent amphipathic polymer as the shell layer by a nano emulsion process. After entering cells, the composite magnetic fluorescent nanoparticles can be used for imaging analysis on the cells respectively by a fluorescence process and a magnetic resonance imaging process. The magnetic fluorescent nano probe disclosed by the invention has high sensitivity and stability, greatly enhances the sensitivity and accuracy of cell imaging, reduces the emergence of false positive and false negative in cell diagnosis and analysis, and can be well used for diagnosing various diseases, such as tumor cells, cancer cells and the like.

The invention relates to a method for preparing a superparamagnetic nanoparticle photocatalyst with a Fe3O4-PAMAM-TiO2 core-shell structure by using polyamide-amine (PAMAM) dendrimer as a template and an isolation layer in a low-temperature aqueous solution. The method is characterized by comprising the following steps: firstly, with the PAMAM dendrimer as the template, preparing a superparamagnetic Fe3O4-PAMAM nanoparticle colloidal solution by using a co-precipitation method; then adding the PAMAM dendrimer with different terminal groups and coating Fe3O4-PAMAM nanoparticles so as to form a dendrimer isolation layer; finally, dropwise adding a TiCl4 absolute ethanol solution, and carrying out normal pressure reaction and hydrothermal reaction so as to obtain the nanoparticles with the Fe3O4-PAMAM-TiO2 core-shell structure and a complete TiO2 shell layer; and carrying out washing and redispersion so as to obtain the nanoparticle photocatalyst with the Fe3O4-PAMAM-TiO2 core-shell structure.

A forward osmosis system using submerged hollow fiber membranes, a draw solution of superparamagnetic nanoparticles (preferably an iron oxide core with a silica shell that is chemically treated with a dispersant stabilizing it in a permanent suspension), that produces an osmotic pressure that drives fluid through the semipermeable membrane and a magnetic field produced by either a permanent magnet or solenoid-type electromagnet that is applied to either separate and reuse or to prevent the movement of the magnetic nanoparticles away from the membrane surface area. Since forward osmosis is independent of both the type of membrane (hyper, nano, ultra, or micro) and the fluid type (the fluid being processed can be oil or water-based), it can be widely applied to many fluid processes within the water treatment (wastewater treatment, demineralizing industrial cooling water, and seawater desalination) and non-water treatment industries such as the food and beverage, medical, and chemical industries.

The invention discloses an exosome preparation derived from a stem cell. The exosome preparation is an exosome secreted by a Fe3O4 superparamagnetic nanoparticle stimulating the stem cell. The invention further provides the application of the exosome preparation in preparing a pharmaceutic preparation for promoting mesenchymal stem cell osteogenic differentiation and the application of the exosomepreparation in preparing a biological agent for treating orthopedic disorders or bone repair materials. In consideration of the complicated pathophysiologic process of osteonecrosis and bone defects,the exosome preparation prepared by the exosome secreted by the Fe3O4 superparamagnetic nanoparticle stimulating the stem cell is adopted, intramuscular administration can be adopted at local bone defect parts, or local filling is performed after the exosome preparation is mixed with absorbable gel, the exosome preparation directly reaches the focus, the osteogenic activity of the mesenchymal stem cell is motivated, the deposition of osteoblasts is promoted, and the repair of the osteonecrosis or bone defects is promoted.