Loading patent…
AssigneeAdvanced Magnetics, Inc.
InventorsErnest V. Groman, Lee Josephson, Jerome M. Lewis
Estimating the term…
This invention relates to materials exhibiting certain magnetic and biological properties which make them uniquely suitable for use as magnetic resonance imaging (MRI) agents to enhance MR images of animal organs and tissues. More particularly, the invention relates to the in vivo use of biologically degradable and metabolizable superparamagnetic metal oxides as MR contrast agents. Depending on their preparation, these metal oxides are in the form of superparamagnetic particle dispersoids or superparamagnetic fluids where the suspending medium is a physiologically-acceptable carrier, and may be uncoated or surrounded by a polymeric coating to which biological molecules can be attached. These materials are administered to animals, including humans, by a variety of routes and the metal oxides therein collect in specific target organs to be imaged; in the case of coated particles, the biological molecules can be chosen to target specific organs or tissues. The biodistribution of the metal oxides in target organs or tissues results in a more detailed image of such organs or tissues because the metal oxides, due to their superparamagnetic properties, exert profound effects on the hydrogen nuclei responsible for the MR image. In addition, the dispersoids and fluids are quite stable and, in the case of the fluids, can even be subjected to autoclaving without impairing their utility. Furthermore, the materials are biodegradable and, in the case of iron oxide compounds, can eventually be incorporated into the subject's hemoglobin, making them useful in treating anemia. Thus, the materials are well-suited for in vivo use.
A method for obtaining an in vivo MR image of an organ or tissue of an animal or human subject which comprises administering to such a subject as a contrast agent an effective amount of a hiodegradable superparamagnetic metal oxide in a physiologically acceptable carrier, said metal oxide (i) having a magnetic saturation between about 5 and about 90 EMU/g of metal oxide at approximately 300.degree. K. and a magnetic squareness of less than 0.1, characteristic of superparamagnetic metal oxide crystals;
A method for obtaining an in vivo MR image of an organ or tissue of an animal or human subject which comprises (a) administering to such a subject as a contrast agent an effective amount of a biodegradable superparamagnetic metal oxide associated with a polymeric substance in a physiologically acceptable carrier, said metal oxide (i) having a magnetic saturation between about 5 and about 90 EMU/g of metal oxide at approximately 300.degree. K. and a magnetic squareness of less than 0.1, characteristic of superparamagnetic metal oxide crystals;
A method for obtaining an in vivo MR image of an organ or tissue of an animal or human subject which comprises, (a) administering to such a subject an effective amount of a superparamagnetic fluid comprising a biodegradable superparamagnetic contrast agent, selected from the group consisting of a metal oxide and a metal oxide associated with a polymeric substance, in an aqueous polycarboxylic acid buffer, said metal oxide:
The method for extending the serum lifetime of a superparamagnetic MR contrast agent in an animal or human subject comprising the steps of:
A method for detecting in vivo blood flow in an animal or human subject comprising the steps of:
A method for reducing anemia in an animal or human subject comprising parenterally administering to such a subject an effective amount of a dispersoid comprising a biodegradable superparamagnetic agent, selected from the group consisting of iron oxide particles and iron oxide particles associated with a polymeric substance, dispersed in a physiologically acceptable carrier, an individual particle (i) comprising one or more biodegradable iron oxide crystals, each crystal about 10 to about 500 angstroms in diameter;
A method for reducing anemia in an animal or human subject comprising parenterally administering to such a subject an effective amount of a superparamagnetic fluid comprising a biodegradable superparamagnetic agent, selected from the group consisting of an iron oxide and an iron oxide associated with a polymeric substance, in an aqueous polycarboxylic acid buffer, said iron oxide:
Dependencies are inferred from the claim text.