37results about How to "High relaxation efficiency" patented technology

The invention relates to a magnetic resonance image contrast agent which uses arabinogalactan as carrier, wherein its production comprises that: using ethylenediamine tetra acetic acid, diethylene triamine pentacetic acid N-butanimide active ester, ethylenediamine tetra acetic acid, or the anhydrides of diethylene triamine pentacetic, via one short connecting arm to react with amination arabinogalactan; forming amido bond to connect ethylenediamine tetra acetic acid or diethylene triamine pentacetic acid to the arabinogalactan, to match magnetic metal ion as manganese, iron or lanthanide rare-earth element, to obtain complex. The invention has significant liver selectivity and low cute toxin. And the inventive contrast agent can be used in magnetic resonance diagnosis, X-ray CT or Y-flashimaging diagnosis.

The invention provides a preparation method and application of a fluorescence-MRI (Magnetic Resonance Imaging) dual-mode image probe, and particularly relates to a dual-mode image probe which combines a fluorescent nanoparticle and a paramagnetic contrast agent and a preparation method thereof, belonging to the field of functional materials. The main process of the method comprises the following step of: removing residues and moisture through dialysis and freeze-drying by taking an amino compound as a surface passivation agent and a gadolinium-based complex as a carbon source material and adopting a one-step forming method to obtain a fluorescence-MRI dual-mode gadolinium-doped carbon quantum dot. The method provided by the invention ahs the characteristics of simple process, low cost and easiness for large-scale production. The fluorescence-MRI dual-mode gadolinium-doped carbon quantum dot prepared through the method has the excellent characteristics of higher fluorescent property, higher relaxation efficiency, good biocompatibility and the like, is successfully applied to in-vitro live cell fluorescence imaging and in-vivo magnetic resonance imaging; the fluorescence-MRI dual-mode gadolinium-doped carbon quantum dot synthesized through the method is about to have wide application prospect in the field of biomedicine.

The invention provides a magnetic resonance image probe based on hyaluronic acid-peptide dendrimer-gadolinium conjugates. The magnetic resonance image probe structurally comprises a plurality of fan-shaped peptide dendrimer and gadolinium conjugates connected onto a hyaluronic acid carbohydrate chain. Hyaluronic acid (HA) is selectively taken as a macromolecular skeleton chain segment, and an MRI contrast agent (Dendronized-HA-Gd) based on the hyaluronic acid-peptide dendrimer-gadolinium conjugates is constructed in combination with the advantages of HA and peptide dendrimer. The structural skeleton has a biodegradable capacity, and a degradable segment is constructed without introducing other sensitive bonds.

The invention discloses a high-efficiency magnetic resonance imaging (MRI) macromolecular contrast agent applied to low-field MRI and a preparation method and application thereof. The MRI macromolecular contrast agent can be prepared according to the following steps of: a) dissolving a fullerene carboxylic acid derivative in a 2-(N-morpholino) ethanesulfonic acid (MES) buffer solution, adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS), and reacting at room temperature to obtain a fullerene carboxylic acid active ester solution; and b) adding gadolinium diethylenetriamine pentaacetic acid human serum albumin (Gd-DTPA-HAS) into the fullerene carboxylic acid active ester solution, stirring, reacting, and then obtaining the MRI contrast agent. The relaxation rate of the Gd-DTPA-HAS-fullerene macromolecular contrast agent is obviously improved under the condition of low field of 0.5T, and obvious tissue contrast ratio can be obtained under the condition of reducing the dosage of the contrast agent; and most importantly, the MRI contrast agent can be used as an MRI molecular probe which can be used for exploring body distribution and metabolism behavior of nanometer materials such as functionalized fullerene derivatives.

The invention discloses the preparation and the application of a superparamagnetic carbon nanotube contrast agent, belonging to the technique magnetic resonance imaging. A traditional magnetic resonance imaging technique has small signal strength difference among benign tumor tissue, malignant tumor tissue and normal tissue and cannot achieve the purpose of accurate diagnosis. A multi-wall carbonnanotube and ferrocene are uniformly mixed to prepare a superparamagnetic multi-wall carbon nanotube by a high-temperature thermal decomposition method; then, after anionic polymers and cationic polymers are assembled and packed by layers, a water-soluble multi-wall superparamagnetic carbon nanotube, the surface of which has amino groups, is prepared and is connected with targeting agent folic acid by chemical bonds to further functional operation; and the water-soluble multi-wall superparamagnetic carbon nanotube is used as a targeting nuclear magnetic resonance contrast agent transfected tocervical cancer Hela cells cultured in vitro for enhancing MRI image effect. The invention has the advantages of simple preparation method of the contrast agent, small toxicity, high relaxation efficiency, good biological compatibility, suitability of various biological systems, good imaging effect and convenient diagnosis.

The invention discloses a manganese-based integrated nanometer material for tumor diagnosis and treatment, a preparation method and an application. In the preparation method, albumin, hypericin and manganese chloride are added into the water medium, and the products are self-assembled to form the integrated nanometer material for tumor diagnosis and treatment. The invention prepares a high-efficiency manganese-based nano-scale macromolecular contrast agent through self-assembly, and has the advantages of high relaxation efficiency, long circulation time in the body, rapid renal clearance, targeting, high biocompatibility, and small toxic and side effects. The nanomaterials prepared by the present invention have higher photodynamic conversion efficiency at 595nm, and can be used as photosensitizers in photodynamic therapy. In addition, the position and size of tumors and the enrichment of phototherapeutic agents in tumor tissues can be monitored by means of magnetic resonance technology. , used to evaluate the therapeutic effect and realize the integration of diagnosis and treatment of photodynamic therapy mediated by magnetic resonance imaging.

A contrast medium for the magnetic resonance (or X-ray CT) imaging of liver with high selectivity and low poison is prepared from the acid byanhydride of EDTA and DTPA and russianolive gum through reaction and then matching with the 2- or 3- valence ions of paramagnetic metal (Mn or Fe) or La- system RE element to obtain a russianolive gum modified paramagnetic metal match.

The invention provides a preparation method and application of a single-atom gadolinium contrast agent supported by hollow nitrogen-doped carbon spheres. The method prepares size-controllable nano-silica microspheres as a template, simultaneously coats dopamine and gadolinium ions on the surface of nano-silica microspheres, and obtains nitrogen-doped carbon-supported single-atom gadolinium through high-temperature calcination; then The silicon dioxide is etched away, and the surface is coated with a hydrophilic polymer to obtain a PEGylated hollow nitrogen-doped carbon sphere loaded monoatomic gadolinium contrast agent. Through the above method, the unique Gd-N-C structure of the present invention can make the monoatomic gadolinium anchored stably by the nitrogen atom without falling off, which improves the biological safety, and the polyethylene glycol coated on the surface further improves its water solubility and biocompatibility; the single-atom contrast agent can make full use of each gadolinium atom, which improves the utilization rate of metal atoms; it has excellent contrast imaging ability and effect, and is a new type of contrast agent with wide application and good prospects.