37 results about "T2 contrast" patented technology

The present invention relates a T1-T2 dual-modal MRI (magnetic resonance imaging) contrast agent, comprising (a) a first layer consisting of T1 contrast material; (b) a second layer consisting of T2 contrast material; and (c) a separating layer which is present in a space between the first layer and the second layer, and inhibits a reciprocal interference between T1 contrast material and T2 contrast material, and a heat-generating composition and a drug delivery composition having the same. The T1-T2 dual-modal contrast agent of the present invention may generate both T1 and T2 signal and thus observe the signal complementarily, resulting in accurate diagnosis through reduction of misdiagnosis. Further, T1 and T2 MR imaging may be simultaneously obtained by simple operation within the same MR imaging device, enabling to remarkably reduce a diagnosis time and diagnosis cost. In addition, the particle constituting the T1-T2 dual-modal contrast agent of the present invention may be applied to hyperthermia and drug delivery systems.

The invention discloses preparation of a photothermal diagnosis and treatment agent based on a gadolinium modified Fe3O4@ PDA nano material, and belongs to a preparation technology of a novel nano composite material. A T1 contrast agent Gd-DTPA and a T2 contrast agent Fe3O4 which have been applied clinically and PDA which has good biological compatibility and near infrared absorbing ability are used; Fe3O4 nano particles with sizes about 10 nanometers are synthesized by a coprecipitation method, and PDA wraps the surfaces of the Fe3O4 nano particles to obtain the Fe3O4@ PDA nano material with good monodispersity; in order to connect Gd-DTPA with the Fe3O4 nano particles, Fe3O4@ PDA is subjected to amination, and finally, the required Fe3O4@ PDA-NH2-DTPA-Gd nano composite material is obtained. Experimental results prove that the material simultaneously has good T1 and T2 imaging effect and photothermal conversion ability.

The invention discloses a preparation method for a high-sensitivity bimodal magnetic resonance contrast agent. According to the preparation method, by means of a method for preparing ferric oleate andmanganese chloride through thermal decomposition, a high-boiling-point solvent is adopted as a reaction medium, oleic acid and oleylamine are used as stabilizers, and therefore manganese oxide embedded iron oxide nanoparticles with narrow particle size distribution and high degree of crystallinity are obtained. The invention particularly relates to a preparation method for modifying the manganeseoxide embedded iron oxide nanoparticles by utilizing the oleic acid/the oleamine, or a preparation method for the biocompatible and water-soluble manganese oxide embedded iron oxide nanoparticles. The preparation method for the high-sensitivity dual-mode magnetic resonance contrast agent has the advantages that the requirements of magnetic resonance imaging for the contrast agent and the characteristics of the Nanotechnology are combined, by means of regulation and control over chemical synthesis, manganese oxide with the T1 contrast capability and superparamagnetic iron oxide nanoparticles with the T2 contrast capability are combined so as to form the manganese oxide embedded iron oxide nanoparticles, and therefore the cooperatively-enhancing dual-mode magnetic resonance contrast effectcan be achieved between the two imaging modes, namely, the T1 imaging mode and the T2 imaging mode.

The invention provides a preparation method for a blending type contrast agent with T1 and T2 contrast functions. The method includes the steps of: dissolving a double-end amphiphilic organic template molecule in certain solvent, then adding aromatic acid, a rare earth chloride and a chloride of VIB-VIIIB group, and carrying out solvothermal reaction at an appropriate temperature, thus obtaining a blending type contrast agent nano-particle with T1 and T2 contrast functions. The blending type contrast agent material prepared by the method provided by the invention has a nanoscale particle size and good T1 and T2 contrast effects.

The invention belongs to the technical field of a nano material, and particularly relates to a ferrate magnetic nanocomposite with a core-shell structure, and a preparation method thereof. The magnetic nanocomposite is applied to a magnetic resonance imaging contrast agent; the nanocomposite takes CoFe2O4 as a core; a ferrate shell layer is wrapped at the surface; and the particle size of the material is 5-20nm. The preparation method comprises the steps of dissolving diacetone zinc/manganese and diacetone iron into an organic solvent; ultrasonically mixing and then adding CoFe2O4 nano particles and 1,2-hexadecanediol; magnetically stirring to obtain a mixed solution; heating the mixed solution under the inert gas atmosphere, cooling reaction liquid; adding absolute ethyl alcohol to the reaction liquid and carrying out centrifugal separation, freezing and drying to obtain a sample. The nano material is even in particle size, good in water-solubility, small in toxic and side effects, good in imaging effect, simple in preparation process of the material, and strong in reaction controllability, and can be used as a T2 contrast agent in magnetic resonance imaging detection.

The invention relates to a ZIF-8 coated ferroferric oxide nanoparticle material and a preparation method and application thereof. Fe3O4 nanoparticles with a T1 weighing MRI effect are embedded in ZIF-8 to obtain the ZIF-8 coated ferroferric oxide nanoparticle material with a T2 weighing MRI effect. In the preparation process of the material, oil-soluble Fe3O4 is synthesized by utilizing a high-temperature pyrolysis method, and the oil-soluble Fe3O4 is prepared into water-soluble Fe3O4 nanoparticles through a ligand exchange method; ZIF-8 coated ferroferric oxide nanoparticles are synthesized through a one-pot synthesis method. Compared with the prior art, the preparation method is simple, the water-soluble Fe3O4 nanoparticles can serve as a T1 contrast medium, Fe3O4@ZIF-8 serves as a T2 contrast medium, Fe3O4@ZIF-8 responds to weak acid and GSH in tumors, MRI contrast transfer happens, and the tumor diagnosis efficiency can be improved.

The invention discloses a magnetic nanoparticle temperature calculation method based on low-field magnetic resonance T2 relaxation, and belongs to the technical field of magnetic nano material testing. Magnetic nanoparticles capable of serving as a T2 contrast agent serve as a medium for temperature-to-magnetic field conversion, and then the temperature characteristic of T2 relaxation time is established. The magnetic nanoparticles have good temperature sensitivity, so that the obtained T2 relaxation time has a linear relationship with the temperature, the temperature change is reflected by measuring the T2 relaxation time, and high-precision temperature measurement is realized. The M-H magnetization curves of the magnetic nanoparticles are measured at different temperatures, the magneticfield dependence of the induction magnetization intensity temperature sensitivity of the magnetic nanoparticles is solved, the magnetic nanoparticles matched with the main magnetic field of the low-field magnetic resonance instrument are preferably selected according to the magnetic field dependence, the induction magnetization intensity temperature sensitivity of the magnetic nanoparticles is maximized, and high-precision temperature measurement is realized.

The invention belongs to the technical field of biomedical materials, particularly relates to mesoporous polydopamine (MPDA) nanoparticles for tumor T1-T2 magnetic resonance imaging, and aims to prepare mesoporous polydopamine nanoparticles which are internally doped with metal and have a T1-T2 bimodal imaging effect. The manganese-mesoporous polydopamine nanoparticles are prepared by taking dopamine hydrochloride and an Mn precursor as basic raw materials and taking F127 and TMB as templates, and the nanoparticles are polydopamine nanoparticles which are internally doped with metal manganese and have a mesoporous structure, and have tumor microenvironment responsiveness, good photothermal conversion capability and good photothermal stability; the nanoparticles have good biocompatibility, and can be used as a T1 contrast agent and a T2 contrast agent for magnetic resonance imaging of tumors at the same time.

The invention discloses a tumor-targeted multi-purpose nanometer drug delivery system as well as a preparation method and applications of the tumor-targeted multi-purpose nanometer drug delivery system. The system comprises multi-purpose nanoparticles modified by tumor penetrating peptide RGERPPR and an anti-tumor medicine, wherein the multi-purpose nanoparticles adopt the T1-T2 dual-mode magnetic resonance contrast agent; the anti-tumor medicine is adriamycin or pharmorubicin; and the weight of the anti-tumor medicine accounts for 10-35 % in the system. The drug delivery system has the following features: the grain diameter is 60-200 nm, and the particles are spherical; the T1 contrast agent Gd-DTPA and the T2 contrast agent Fe3O4 are simultaneously utilized, and the highly accurate diagnosis information is provided; the water solubility and biocompatibility of the medicine are improved, and the curative effects and bioavailability of the medicine are improved; the drug delivery system can be used for intravenous injection, and targets to the tumor tissue by utilizing the RGERPPR mediation effect and the tumor EPR effect, and the system has the obvious inhibiting effect for the growth of the brain glioma tumor; and the drug delivery system can be used for realizing the tumor diagnosis and treatment integration.

The invention provides a T1-T2 double-activated magnetic resonance imaging contrast agent as well as a preparation method and application thereof. The T1-T2 double-activated magnetic resonance imagingcontrast agent has a core-shell structure and sequentially comprises T2 contrast agent nanoparticles, a silicon dioxide layer, a T1 contrast agent layer and a modification layer from inside to outside, and the T2 contrast agent nanoparticles are superparamagnetic iron oxide nanoparticles. The T1-T2 double-activated magnetic resonance imaging contrast agent is in a T1 and T2 contrast agent signaldouble-quenching state in normal tissues around an in-vivo tumor, and T1 and T2 contrast agent signals can be activated at the same time at a tumor part, so that the tumor part and the surrounding normal tissues have a remarkable MRI signal difference, and the T1-T2 double-activated magnetic resonance imaging contrast agent has targeting property on tumor cells, so as to realize high-quality imaging for the tumor part.

The present invention relates a T1-T2 dual-modal MRI (magnetic resonance imaging) contrast agent, comprising (a) a first layer consisting of T1 contrast material; (b) a second layer consisting of T2 contrast material; and (c) a separating layer which is present in a space between the first layer and the second layer, and inhibits a reciprocal interference between T1 contrast material and T2 contrast material, and a heat-generating composition and a drug delivery composition having the same. The T1-T2 dual-modal contrast agent of the present invention may generate both T1 and T2 signal and thus observe the signal complementarily, resulting in accurate diagnosis through reduction of misdiagnosis. Further, T1 and T2 MR imaging may be simultaneously obtained by simple operation within the same MR imaging device, enabling to remarkably reduce a diagnosis time and diagnosis cost. In addition, the particle constituting the T1-T2 dual-modal contrast agent of the present invention may be applied to hyperthermia and drug delivery systems.

Disclosed are nanoparticles comprising octapod iron oxide having eight trigonal bipyramidal arms and a method of preparing the same. The nanoparticles are prepared by heating a mixture of a ferric carboxylate, a carboxylic acid, a chloride salt, water, and a non-polar solvent, to a temperature above about 300° C. Also disclosed is a method of magnetic resonance imaging a tissue in a mammal, comprising use of the aforesaid nanoparticles.

The invention discloses a T2 contrast agent and a preparation method and applications thereof. The T2 contrast agent comprises a gadolinium based nano material and a silica layer. The silica layer covers at least part of the external surface of the gadolinium based nano material. The T2 contrast agent has a good water soluble property and biocompatibility. The T2 contrast agent is especially suitable for observing the fine structure of lesion under a high magnetic field and the contrast effect is excellent.

The invention relates to a magnetic resonance imaging T₂ contrast medium (agent) for cell contrasting, and to a method for manufacturing the same. The magnetic resonance imaging T₂ contrast agent for imaging at cellular level comprises magnetic nanoparticles exhibiting ferrimagnetism at room temperature, has a very high relaxivity, and has an effective uptake into cells. Thus, the T₂ contrast agent may effectively mark various types of cells, and in vitro and in vivo magnetic resonance imaging at the single cell level may he realized.

An embodiment in accordance with the present invention provides concurrent measurement of motion during T2-weighted magnetic resonance imaging. The present invention combines T2 preparation, a module used to impart T2 contrast, and motion measurement, tracking, and/or correction. The present invention provides for the expedition of more efficient motion compensation during T2-weighted imaging. The proposed invention can be used to provide a variety of measurements of motion, with no overhead in imaging time. The proposed invention also enables T2 contrast imaging to be executed while a subject is breathing freely, without the additional time cost associated with the standard motion tracking methodologies.

The invention provides a contrast medium for pancreatic cancer MR imaging. The contrast medium comprises pegylated iron oxide nanoparticles and single-chain antibodies for surface moficiation. The single-chain antibodies are coupled with the pegylated iron oxide nanoparticles and selected from an anti-MUC4 single-chain antibody, an anti-CEACAM6 single-chain antibody and an anti-CD44v6 single-chainantibody. Single-chain antibody modified INOPs (iron oxide nanoparticles) can serve as an MR imaging T2 sequence contrast medium. The INOPs modified with three types of single-chain antibodies are superior to the INOPs modified with two types of single-chain antibodies in negative developing effect and lasting time; The INOPs modified with two types of single-chain antibodies are superior to theINOPs modified with one type of single-chain antibody in negative developing effect and lasting time. The single-chain antibody modified INOPs can be gathered in a tumor area and less retained in spleen, and hepatic and renal toxicity after radiography is avoided. A IONPs complex modified with the three types of single-chain antibodies can be used as a novel sensitive and efficient MR imaging T2 contrast medium, has an anti-pancreatic-cancer effect and is a pancreatic cancer diagnosis and treatment integrated difunctional nanomaterial.

The invention discloses a dynamic organic gadolinium nanoparticle and application thereof. The nanoparticle is prepared by the following method: 1, respectively preparing a 100 [mu] M gadolinium precursor aqueous solution and a 4 mM tris (2-carboxyethyl) phosphine aqueous solution; 2, mixing the gadolinium precursor aqueous solution and the tris (2-carboxyethyl) phosphine aqueous solution according to the molar ratio of the gadolinium precursor to the tris (2-carboxyethyl) phosphine of 25: 1, and stirring at room temperature to obtain a gadolinium intermediate; and 3, adjusting the pH value of the gadolinium intermediate to 6.0 by using a Na2CO3 aqueous solution, and stirring at room temperature to obtain the dynamic organic gadolinium nanoparticle. The particle size of the nanoparticle can be dynamically changed in different stages of self-assembly, the nano-particles can be used as a T1 contrast agent and a T2 contrast agent in different stages of self-assembly, the same contrast agent can realize positive enhancement and negative enhancement effects of MRI signals, and the detection accuracy can be effectively improved.

The invention discloses a pH-responsive T1/T2 switching type MRI (Magnetic Resonance Imaging) contrast agent as well as a preparation method and application thereof. The T1/T2 switching type MRI contrast agent has a structure shown in the following formula, wherein X is selected from 30-50, or m and n are selected from 30-50; and M is ferric oxide nanoparticles. The MRI contrast agent provided by the invention can specifically respond in a weak acid microenvironment of tumors, so that surface charges of contrast agent particles are changed, and aggregation of the ferric oxide nanoparticles is realized through electrostatic interaction, switching from a T1 contrast agent to a T2 contrast agent is realized, a T2 contrast enhancement effect is activated, and the MRI contrast agent has the advantages of high sensitivity and selectivity, low toxicity, good biocompatibility and the like in tumor diagnosis.

The invention discloses an application of a mitochondrial targeting contrast media molecule as a T2 contrast media. The mitochondrial targeting contrast media molecule includes a phosphonium cation, which is combined with cell mitochondria and has a structure general formula like <->P<+>(X1)(X2)(X3), and a superpara-magnetic metal complex used as a radiography unit for enhancing contrast ratio of magnetic resonance imaging. The invention also discloses the mitochondrial targeting contrast media molecule and a preparation method thereof, wherein one or more <->P<+>(X1)(X2)(X3) cations are combined with 1-8 superpara magnetic metal complex molecules through dendritic or linear molecules, meanwhile, a connexon and a spacer are employed for improving the spatial structures between the <->P<+>(X1)(X2)(X3) cations and the dendritic or linear molecules and between the dendritic or linear molecules and the superpara magnetic metal complex. The invention further discloses magnetically labeled cells labeled by the mitochondrial targeting contrast media molecule, a combination of the magnetically labeled cells and a scaffold material, and a method of performing magnetic resonance image in-vivo tracing therewith.

The invention discloses an MRI (Magnetic Resonance Imaging) contrast agent based on water-soluble polymer modified magnetic nanoparticles and a preparation method of the MRI contrast agent. The contrast agent comprises Fe3O4 nanoparticles, the surfaces of which are modified with pentaerythritol tetra-3-mercaptopropionate-polyvinyl pyrrolidone (PTMP-PVP). The method comprises the following steps of: obtaining a water-soluble polymer PTMP-PVP by taking pentaerythritol tetra-3-mercaptopropionate (PTMP) as a chain transfer agent and N-vinyl pyrrolidone (VP) as a monomer through free radical polymerization; and then, synthesizing the Fe3O4 nanoparticles coated with the PTMP-PVP by using a coprecipitation method and taking an iron precursor solution as a raw material and the PTMP-PVP as a protective agent. The Fe3O4 nanoparticles prepared by the invention have good stability, biocompatibility and size uniformity, also have a relatively high relaxation rate ratio, and have the potential of being used as a T2 contrast agent.

The invention discloses a bionic nano diagnosis and treatment agent for ultrahigh field magnetic resonance imaging and a preparation method thereof, and the nano diagnosis and treatment agent Ho-MPDA is prepared by doping water-soluble dopamine (PDA) with holmium ions (Ho < 3 + >) through a method of doping metal before polymerization. The Ho-MPDA has an obvious T2 contrast enhancement effect under the ultrahigh field intensity of 7.0 T, and the transverse electron relaxation time is obviously shortened. And the transverse relaxation rate T2 (102.71 mM <-1 > S <-1 >) of the Ho-MPDA under the ultrahigh field intensity of 7.0 T is 4.02 times that of a T2 contrast agent (25.52 mM <-1 > S <-1 >), and the imaging effect is greatly improved. Meanwhile, the polydopamine carrier has good biocompatibility, excellent photo-thermal conversion capacity and good light stability, and photo-thermal therapy is achieved under the guidance of ultrahigh-field magnetic resonance imaging.