33 results about "Gadolinium-Chelate" patented technology

The invention relates to a novel preparation method and application of a cationic amphiphilic tetra-armed star polymer. In particular, the star polymer can be obtained through synthetic means such as atom transfer radical polymerization (ATRP) and click chemistry. A core of the star polymer is tetraphenylethylene with the characteristic of aggregation-induced emission. A polymer linear arm is a cationic amphiphilic random copolymer with excellent antibacterial effects. A covalently labeled T1 type magnetic resonance (MR) contrast agent is an organic gadolinium chelate. By using the cationic amphiphilic tetra-armed star polymer, fluorescence/MR double quantitative detection of Gram positive and negative bacteria with negative charges on the surfaces in the environment of pure water is achieved, and meanwhile good antibacterial effects are gained.

The invention discloses an MRI contrast agent taking a chitosan derivative as a carrier and a preparation method of the contrast agent. The contrast agent comprises chitosan which serves as a main body of the contrast agent and modified with polyethylene glycol and a secondary polyamide dendrimer which is mainly connected to a main chain of chitosan and provided with a gadolinium chelate. The preparation method of the contrast agent comprises the steps that chitosan modified with polyethylene glycol is provided, a chelating ligand of gadolinium is coupled to the secondary polyamide dendrimer modified with an alkynyl group, then the modified secondary polyamide dendrimer is connected to chitosan, and the contrast agent is obtained. The MRI contrast agent taking the chitosan derivative as the carrier is good in biocompatibility, easy to biologically degrade and high in relaxation rate, the preparation method is simple, the needed reaction temperature is moderate, and control is easy.

The invention relates to a preparation method of a bifunctional contrast agent based on an up-conversion material and a gadolinium chelate. The preparation method comprises following steps: preparing surface-aminated silica by utilization of the combined action of tetraethoxysilane (TEOS) and (3-aminopropyl)trimethoxysilane (APTES) and by utilization of an up-conversion nano material as a substrate; coupling a chelate to the surface-aminated silica by utilization of 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as coupling agents; and finally reacting with a gadolinium salt to obtain the gadolinium chelate, and therefore the bifunctional contrast agent combined the up-conversion material and the gadolinium chelate is obtained. The raw materials used in the preparation method have high biosecurity, and some of the raw materials are already commercial products. The preparation method has simple technology and strong operationality, and can satisfy production and applications. The bifunctional contrast agent prepared has good physical and chemical stability, luminescence performance and magnetic resonance imaging performance.

The invention discloses a manganese gadolinium heterozygous bimetallic paramagnetic nanocolloid and application in preparation of a magnetic resonance imaging contrast material thereof. The invention designs, synthesizes and evaluates a hybrid ''bimetallic'' magnetic resonance imaging nanocolloid composed of manganese element and trace gadolinium. Research shows that: the high relaxation rate of the nanocolloid provided by the invention derives from high concentration manganese oleate molecules suspending at the core of nanoparticles, and the small molecules can penetrate a phospholipid film layer to come into contact with a critical surface of water and nanoparticles. Integration of trace gadolinium chelates on the surfaces of the nanoparticles can provide an additional relaxation rate, thereby affecting the relaxation effect of surrounding protons. The manganese gadolinium heterozygous bimetallic paramagnetic nanocolloid provided by the invention can maximumly reduce gadolinium agent load, lower the side effects of gadolinium chelates and improve the biological safety, thus reaching the purpose of improving the nanoparticle r1 paramagnetic magnetic resonance contrast effect.

The invention discloses a chitosan-based MRI contrast medium and a preparation method. The contrast medium comprises polyethyleneimine-grafted chitosan taken as a main body of the contrast medium and a gadolinium chelate mainly connected to side chains of polyethyleneimine-grafted chitosan. Furthermore, the contrast medium also comprises a targeting group, such as folic acid, connected to side chains of polyethyleneimine-grafted chitosan. The preparation method comprises: firstly, providing polyethyleneimine-grafted chitosan, then coupling a gadolinium chelating ligand, such as diethylene triamine pentaacetic acid to polyethyleneimine-grafted chitosan, enabling the obtained product together with Gd3+ to form the gadolinium chelate, and optionally connecting the targeting group, such as folic acid to the obtained polyethyleneimine-grafted chitosan to produce the contrast medium. The chitosan-based targeting MRI contrast medium is good in biocompatibility, is easy to biologically degrade, and has a high relaxation rate. The preparation method is simple, needs medium reaction temperature, and is easy to control.

The invention discloses a preparation method of a tumor targeting gadolinium-based magnetic resonance imaging contrast agent and biomedical application of the tumor targeting gadolinium-based magneticresonance imaging contrast agent. The contrast agent can be specifically bound to a transferrin receptor 1 highly expressed on the surfaces of tumor cells, and consists of genetic engineering recombinant proteins and a gadolinium chelate, and has a higher longitudinal relaxation rate than a commercial contrast agent of Magnevist (Gd-DTPA). The animal tumor model imaging effect comparison with theMagnevist is provided; the result indicates that the contrast agent provided by the invention can realize the tumor specific recognition and longer-time magnetic resonance imaging at a lower injection dose; and repeated injection is not needed. The contrast agent provided by the invention can be used through intravenous administration, and can be applied to early diagnosis of cancer, further identification of tumor metastasis and diagnosis of suspected postoperative recurrence.

The invention provides tumor targeting MRI contrast agent and a preparation method thereof. The contrast agent is characterized by comprising a micromolecule gadolinium chelate part and a targeting carrier part, wherein the micromolecule gadolinium chelate part and the targeting carrier part are coupled through a covalent bond, the micromolecule gadolinium chelate part is Gd-DO3A, and the targeting carrier part contains EBP molecules. The contrast agent is good in relaxation enhancement ability, can be combined with EGFR of tumor cells in a targeting mode, has a strong targeting radiography effect and has strong practicability. Furthermore, the imaging time of the contrast agent in a body is prolonged, and the adding amount of the contrast agent is reduced.

A method for determining the presence or amount of a gadolinium chelate in a biological sample. The method includes contacting a biological sample with a dye selected from arsenazo III or chlorophosphonazo at low pH, and measuring the absorbance of the sample, thereby determining the presence or amount of gadolinium in the sample. A method for determining glomerular filtration (GFR) rate in a mammal. The method includes administering to the mammal an amount of a gadolinium chelate and determining the concentration levels of the chelate in biological samples taken from the animal at plurality of intervals following administration of the chelate. The concentration levels of the chelate are correlated to GFR.

The present invention relates to a new class of high relaxivity extracellular gadolinium chelate complexes, to methods of preparing said compounds, and to the use of said compounds as MRI contrast agents.

The invention discloses a magnetic resonance imaging contrast agent and a preparation method and application thereof. The preparation method comprises the following steps: reacting alpha,omega-biscystamine polyethylene glycol with alpha-cyclodextrin to form pseudopolyrotaxane; then terminating pseudopolyrotaxane with Z-tyrosine to obtain Z-tyrosine terminated polyrotaxane; then reacting the Z-tyrosine terminated polyrotaxane with propargyl carbonylimidazole to form polyrotaxane surface-modified by alkynyl groups and capable of being quickly reduced and cracked; reacting the polyrotaxane surface-modified by alkynyl groups with a lysine second-generation dendrimer with azide as an end group by means of click chemistry so as to form lysine second-generation dendrimer-grafted cleavable polyrotaxane; and bonding the lysine second-generation dendrimer-grafted cleavable polyrotaxane with a gadolinium chelate, and loading gadolinium to form the gadolinium chelate-modified lysine second-generation dendrimer-grafted cleavable polyrotaxane. The magnetic resonance imaging contrast agent is good in biocompatibility, low in toxicity and high in relaxation rate; and in addition, an AS1411 aptameris introduced as a targeting molecule to realize multivalent targeting of tumor cells and tumors with cell membrane overexpression of nucleolin, so in-vivo magnetic resonance imaging of tumors is facilitated.

A compound having the formula of tetragadolinium [4,10-bis(carboxylatomethyl)-7-{-3,6,12,15-tetraoxo-16-[4,7,10-tris(carboxylatomethyl)-1,4,7,10-tetraazacyclododecan-1-yl]-9,9-bis({[{2-[4,7,10-tris(carboxylatomethyl)-1,4,7,10-tetraazacyclododecan-1-yl]propanoyl} amino)acetyl]amino}methyl)-4,7,11,14-tetraazaheptadecan-2-yl}-1,4,7,10-tetraazacyclo dodecan-1-yl]acetate wherein the stereochemistry at the chiral carbon of the four alanine substituents is selected from the group consisting of RRRR, SSSS, RSSS, RRSS, and RRRS stereoisomers, and racemic and diastereomeric mixtures of any thereof, or a tautomer, a hydrate, a solvate, or a salt thereof, or a mixture of same is described. The compounds may be used as an MRI contrast imaging agent.

The invention provides a contrast agent as well as a preparation method and application thereof. Erythrocyte in blood is used as a matrix, by loading the gadolinium chelate onto red blood cells by a hypotonic precipitation method, a novel electroporation method, a drug induction method and a drug induction method under a hypotonic condition, the gadolinium chelate has the advantages that the volume of the gadolinium chelate is increased, the migration of the gadolinium chelate to the outside of a blood vessel is blocked, the technical problem that an existing magnetic resonance contrast agentis easy to migrate to a gap outside the blood vessel is solved, and the contrast agent has wide application in the fields of magnetic resonance imaging and imaging.

The invention discloses a preparation method and biological application of T1-T1 synergistic effect gadolinium chelate manganous-manganic oxide nano particles. The preparation method and the biological application of the T1-T1 synergistic effect gadolinium chelate manganous-manganic oxide nano particles include that firstly manganeseacetylacetonate is combined, and then oleylamine is used as a solvent, a high-temperature pyrolysis method is used to combine oil solubility manganous-manganic oxide nano particles, and then a ligand exchange method is utilized to use alendronate to be exchanged on the surfaces of the manganous-manganic oxide nano particles, so that nano particles are formed, wherein the surfaces of the nano particles are provided with a large number of amino groups. Then, the surfaces of the amino groups are connected with diethylenetriamine pentaacetic acid, so that the surfaces of the nano particles are provided with a large number of carboxyl groups, and at last a chelate effect is utilized to enable the large number of carboxyl groups and gadolinium to be chelated. Therefore, gadolinium chelate manganous-manganic oxide nano particles are obtained. The preparation method is low in requirement for equipment, convenient for operated process, low in needed raw material cost, and nuisanceless in accessory products. And at last through in vitro and in vivo magnetic resonance imaging experimental testing, so that compared with independent manganese and independent gadolinium, T1 magnetic resonance imaging contrast effect is strengthened.

The invention discloses a preparation method for a contrast medium intermediate for medical diagnosis, and the intermediate is a key intermediate for macromolecule gadolinium chelate contrast medium.According to the method, benzylethanolamine is adopted as a starting raw material, and the product N',N'',N''',N''''-tetraazacyclododecane is obtained through backflow water diversion, sulfonation andpolymerization reaction. According to the method, methylbenzene, water and methyl alcohol are all recycled, resource saving and the environmental-friendly function are realized, the cost is saved, the product is stable in quality and high in yield, and the method is suitable for large-scale industrial stable production.