298 results about "MRI contrast agent" patented technology

Disclosed are nanocrystals comprising metals and metal alloys, which are formed by a process that results in a layer of graphite in direct contact with the metallic core. The nanocrystals may be used in vivo as MRI contrast agents, X-ray contrast agents, near IR (NIR) heating agents, drug delivery, protein separation, catalysis etc. The nanocrystals may be further functionalized with a hydrophilic coating, e.g., phospholipid-polyethylene glycol, which improves in vivo stability. The process comprises chemical vapor deposition of metals adsorbed onto silica as a fine powder, in conjunction with a carbon containing gas, which coats the metal particles. The silica is then etched away. Preferred metals include iron, gold, cobalt, platinum, ruthenium and mixtures thereof, e.g., FeCo and AuFe. The process permits control of the alloy compositions, size, and other characteristics.

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.

A method of multidimensional modeling a magnetic resonance device (MRD) contrast agent introduced within the body of a patient. The method includes: introducing into the patient body or an organ an effective measure of at least one MRD contrast agent; imaging the MRD contrast agent located at least a portion of a body and providing data defining a multidimensional image; loading or otherwise streaming the MRD image to a multidimensional printer; and multidimensionally modeling the MRD contrast agent.

The present invention includes PG polymer complexes with paramagnetic materials, such as Gd, Mn and iron oxide. The complexes may also include chelating agents which may be covalently attached to the PG polymer backbone through linkers. PEG may also be attached to the PG polymer backbone. The complexes may include targeting molecules. The complexes are useful as MRI contrast agents, particularly as blood pool agents.

Gadolinium⁺³ (Gd³⁺) containing (or incorporated) Prussian blue lattice contrast agents that can be used as an MRI contrast agent have unexpectedly improved r₁ relaxivities of 1 or 2 magnitudes higher than the commercial Gd³⁺-chelates as well as exceedingly, non-toxic, low release of the Gd³⁺ ions into an aqueous environment at a pH of about 2 to about 7.5. The Prussian blue lattice containing Gd³⁺ ions therein can be used for clinical diagnosis intravenously to human beings for medical imaging. The particle sizes of the doped Prussian blue lattices are of a nanosize scale and are very stable against agglomeration.

Disclosed herein are nanostructures comprising a polymeric framework comprising at least five geminal bisphosphonate groups, wherein the geminal bisphosphonate groups independently of each other are incorporated as —R³R⁴C(P═O(OR¹)(OR²))₂, wherein R¹ and R² are independently selected from the group consisting of a negative charge, H, alkyl and aryl, and wherein at least one of R³ and R⁴ is a group connected to the polymeric framework with the proviso that when only one of R³ and R⁴ is such a connected group, the other of R³ and R⁴ is either a group being able to connect to the polymeric framework, or the residue of such a group, or selected from the group consisting of H, OH, OR⁵ and R⁵, wherein R⁵ is a lower alkyl. The polymeric framework may comprise manganese ions. Disclosed are also methods for producing such manganese containing nanostructures, compositions comprising such manganese containing nanostructures and use of such manganese containing nanostructures, i.a. as MRI contrasting agents.

Iron oxide nano contrast agents for Magnetic Resonance Imaging which have superior T₂ contrast effect, and also can be used as a storage or a carrier for drugs and so on, are disclosed. The iron oxide nano contrast agents can be prepared by the steps of: coating surfaces of hydrophobic FeO nanoparticles with a coating material selected from the group consisting of polyethylene glycol-phospholipid conjugate, dextran, chitosan, dimercaptosuccinic acid and mixtures thereof in an organic solvent to form hydrophilic FeO nanoparticles having hydrophilic surfaces and dispersibility in water; dispersing the hydrophilic FeO nanoparticles in water to oxidize FeO; and exposing the oxidized hydrophilic FeO nanoparticles to an acidic buffer to dissolve and remove interior unoxidized FeO portions, and thereby to form Fe₃O₄ nanoparticles having an interior space.

The present invention includes compositions, methods and methods for using MRI contrast agent that include a generally nanotubular carrier and an MRI contrast agent disposed within the carrier.

The present invention relates to an MRI contrast agent that includes zinc-containing water-soluble metal oxide nanoparticles and has an improved contrast effect. The zinc-containing water-soluble metal oxide nanoparticles are characterized by addition of zinc to a matrix comprising the metal oxide nanoparticles or by substitution of metal in the matrix, resulting in the improved contrast effect of MRI. In addition, the zinc-containing metal oxide nanoparticles of the present invention include the MRI contrast agent t having hybrid structures of “zinc-containing metal oxide nanoparticle—biologically/chemically active material” in which the nanoparticle is conjugated with a bioactive material such as proteins, antibodies, and chemical materials.

The invention relates to a preparation method for a nanometer graphene carrier used for an MRI contrast agent. According to the method, nanometer graphene oxide and hydrophilic high polymers are used as raw materials; the hydrophilic high polymers are grafted onto the surface of nanometer graphene oxide, and a contrast agent is loaded wherein. Compared to the prior art, the invention has the following advantages: by utilizing good hydrophilicity and biocompatibility of some hydrophilic high polymers and the characteristic that the system of nanometer graphene oxide and hydrophilic high polymers can enter into biological cells at a nanometer level, the contrast agent is enabled to have long in-vivo retention time, good histocompatibility and low cytotoxicity; the system shows a good application prospect in the aspect of MRI radiography.

A contrast marker having a casing and a novel MRI contrast agent comprising metal complexes disposed around, within, or abuting the casing is provided. Such contrast markers may be placed in a strand, with or without a therapy seed, to produce a seeded strand useful for imaging and in connection with brachytherapy.

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.

A magnetic resonance imaging (MRI) contrast enhancement agent comprising an elastin-like polypeptide (ELP) and one or more paramagnetic metal ions is disclosed. Also disclosed are methods of preparing ELP MRI contrast enhancement agents, formulations comprising ELP MRI contrast enhancement agents, and methods of using ELP MRI contrast enhancement agents to image biological samples and to image and deliver therapeutic agents to targeted sites in vivo. In some embodiments, the ELP MRI agents can be used in methods related to blood volume determination, in magnetic resonance angiography (MRA), and in vascular transport determinations. The ELP MRI contrast agents can also provide information on the expression of various proteins through affinity targeting or enzymatic crosslinking in order to aid in diagnosis and in the spatial definition of pathologic tissue.

A contrast agent for magnetic resonance imaging comprising a complex of a paramagnetic cation, preferably Gd⁺³, Dy⁺³, and Fe⁺³ with three equivalents of a charge neutralizing chelator that provides a lipid soluble complex of the paramagnetic cation is described. The complex is retained intracellularly when introduced into a mammalian cell. A method of providing an image of an internal pathology of a patient by magnetic resonance imaging (MRI) by administering the MRI contrast agent or tagged cells to the patient and scanning the patient using magnetic resonance imaging to obtain visible images of the internal pathology of the patient is also set forth.

The invention relates to d-glucosamine-modified iron oxide nanoparticles used as a tracer for magnetic resonance, a preparation method of lyophilized powder thereof and use thereof. The d-glucosamine-modified iron oxide nanoparticles comprise superparamagnetic iron oxide nanoparticles, wherein the surfaces of the superparamagnetic iron oxide nanoparticles are modified by a substance having carboxyls; the carboxyls react with the aminos of the d-glucosamine to form amido bonds; and thus a structure that the surfaces of the superparamagnetic iron oxide nanoparticles are modified by the d-glucosamine is formed. The invention provides a novel tumor-targeted MRI contrast agent which has high selectivity of tumors for the tumor targeted magnetic resonance diagnostic tests and clinic tumor diagnosis. By preserving the d-glucosamine-modified superparamagnetic iron oxide nanoparticles in form of the lyophilized powder, the unstable problem of the d-glucosamine-modified superparamagnetic iron oxide nanoparticles is solved. The d-glucosamine-modified iron oxide nanoparticles are sterile, anhemolytic and free from vascular stimulation and can meet the requirements of tests of cells, animals and the like.

Macromolecular contrast agents for magnetic resonance imaging are described. Biomolecules and their modified derivatives form stable complexes with paramagnetic ions thus increasing the molecular relaxivity of carriers. The synthesis of biomolecular based nanodevices for targeted delivery of MRI contrast agents are described. Nanoparticles (NP) have been constructed by self-assembling of chitosan (CHIT) as polycation and poly-gamma glutamic acids (PGA) as polyanion. NP's are capable of Gd-ion uptake forming a particle with suitable molecular relaxivity. Folic acid (FA) is linked to the NP's to produce NP-FA bioconjugates that can be used for targeted in vitro delivery to a human cancer cell line.

Atherosclerosis is an inflammatory disease of the arterial walls and represents a significant health problem in developed nations. Described is a targeted Magnetic Resonance Imaging (MRI) contrast agent for in vivo imaging of early stage atherosclerosis. Early plaque development is characterized by the influx of macrophages, which express a class of surface receptors known collectively as the scavenger receptors (SR). The macrophage scavenger receptor class A (SRA) is highly expressed during early atherosclerosis. The macrophage SRA therefore presents itself as an ideal target for labeling of lesion formation. By coupling a known ligand for the scavenger receptor, dextran sulfate, to a MRI contrast agent, early plaque formation can be detected in vivo. Targeted MR contrast agents offer a unique opportunity to visualize early plaque development in vivo with high sensitivity and resolution, allowing or early diagnosis and treatment of atherosclerosis.

Small dendrimer-based MRI contrast agents are disclosed to accumulate in renal tubules. The accumulation enables visualization of renal structure and function, permitting assessment of structural and functional damage to the kidneys. In a disclosed embodiment, six, small dendrimer-based MRI contrast agents were synthesized, and their pharmacokinetics, whole body retention, and renal MRI images were evaluated in mice. Surprisingly, despite having unequal renal clearance properties, all of the dendrimer agents clearly visualized the renal anatomy and proximal straight tubules of the mice better than Gd-[DTPA]-dimeglumine. Dendrimer conjugate contrast agents prepared from PAMAM-G2D, DAB-G3D, and DAB-G2D dendrimers were excreted rapidly and may be acceptable for use in clinical applications.

The present invention relates to a magnetic resonance imaging (MRI) contrast agent, particularly a metal oxide nanoparticle-based T1-T2 dual-mode MRI contrast agent that can be used not only as a T1 MRI contrast agent but also as a T2 MRI contrast agent, and a method for producing the same. The metal oxide nanoparticle-based T1-T2 dual-mode MRI contrast agent can provide more accurate and detailed information associated with disease than single MRI contrast agent by the beneficial contrast effects in both T1 imaging with high tissue resolution and T2 imaging with high feasibility on detection of a lesion.

The present invention relates a dual-modality PET (positron emission tomography)/MRI (magnetic resonance imaging) contrast agent, a hybrid nanoparticle comprising: (a) a magnetic signal generating core; (b) a water-soluble multi-functional ligand coated on the signal generating core; and (c) a positron emitting factor linked to the water-soluble multi-functional ligand. The contrast agent of the present invention is the dual-modality contrast agent enabling to perform PET and MR imaging and can effectively obtain images having the merits of PET (excellent sensitivity and high temporal resolution) and MR (high spatial resolution and anatomical information) imaging. The contrast agent of the present invention is very useful for non-invasive and highly sensitive real-time fault-free imaging of various biological events such as cell migration, diagnosis of various diseases (e.g., cancer diagnosis) and drug delivery.

Potential magnetic resonance imaging (MRI) contrast agents that are functionalized with crown compounds have been synthesized, and show target-specificity to the kidney and liver, along with excellent water solubility, high MR intensity enhancement efficiency, long resident lifetime, low dosage requirement, low cytotoxicity and prolonged excretion rate.