Electromagnetic wave absorbing, surface modified magnetic particles for use in medical applications, and their method of production

• US 5,441,746 A
• Filed: 05/05/1993
• Issued: 08/15/1995
• Est. Priority Date: 12/22/1989
• Status: Expired due to Fees

• Current Assignee: Molecular Bioquest, Inc.
• Original Assignee: Molecular Bioquest, Inc.
• Inventors: Chagnon, Mark S.
• Primary Examiner(s): Kishore, Gollamudi S.
• Application Number:
  US08/057,687
• Time in Patent Office: 832 Days
• Field of Search: 424/450, 424/490, 424/498, 424/600, 424/617, 424/630, 424/635, 424/639, 424/641, 424/644, 424/646, 424/650, 428/402.2
• US Class Current: 424/450
• CPC Class Codes: A61K 47/6923 the form being an inorganic particle, e.g. ceramic particles, silica particles, ferrite or synsorb
• CPC Class Codes: A61K 47/6929 the form being a nanoparticle, e.g. an immuno-nanoparticle
• CPC Class Codes: A61K 49/1812 liposomes, polymersomes, e.g. immunoliposomes
• CPC Class Codes: A61K 49/1839 the small organic molecule being a lipid, a fatty acid having 8 or more carbon atoms in the main chain, or a phospholipid
• CPC Class Codes: A61K 9/1272 with substantial amounts of non-phosphatidyl, i.e. non-acylglycerophosphate, surfactants as bilayer-forming substances, e.g. cationic lipids with cholesterol as the only non-phosphatidyl surfactant A61K9/127; lipids as modifying agent A61K47/543
• CPC Class Codes: B03C 1/01 by addition of magnetic adjuvants
• CPC Class Codes: C12N 11/14 Enzymes or microbial cells immobilised on or in an inorganic carrier
• CPC Class Codes: G01N 2446/20 the magnetic material being present in the particle core
• CPC Class Codes: G01N 2446/80 characterised by the agent used to coat the magnetic particles, e.g. lipids
• CPC Class Codes: G01N 2446/84 Polymer coating, e.g. gelatin
• CPC Class Codes: G01N 2446/90 characterised by small molecule linker used to couple immunoreagents to magnetic particles
• CPC Class Codes: G01N 33/54313 the carrier being characterised by its particulate form
• CPC Class Codes: G01N 33/5434 using magnetic particle immunoreagent carriers which constitute new materials per se
• CPC Class Codes: G01N 33/551 the carrier being inorganic
• CPC Class Codes: G01N 33/554 the carrier being a biological cell or cell fragment, e.g. bacteria, yeast cells
• CPC Class Codes: Y10T 428/2989 Microcapsule with solid core [includes liposome]

Abstract

This invention describes an electromagnetic wave-absorbing surface modified magnetic particle for use in medical applications. The magnetic particles are coated with an amphipathic organic compound and an amphipathic vesicle forming lipid. These particles may be used in a method of treatment of cancer, as well as for the treatment of infectious disease. For cancer treatment the invention comprises providing a patient said coated particles, absorbing the coated particle intracellularly into the cancer cell, and subjecting the patient to an alternating electromagnetic field to inductively heat the magnetic core particle along with the cancer cells. The inductive heating of the magnetic core particle is then continued so as to achieve an increase in intracellular temperature which selectively kills the cancer cells.

Claims

1. A composition comprising a wave absorbing magnetic core particle wherein said magnetic core particle comprises an oxide of the formula M₂ (+3)M(+2)O₄ wherein M(+3) is Al, Cr or Fe, M(+2) is Fe, Ni, Co, Zn, Ca, Ba, Mg, Ga, Gd, Mn or Cd, in combination with an oxide selected from the group consisting of LiO, CdO, NiO, FeO, ZnO, NaO, KO and mixtures thereof, characterized in that said core is capable of adsorbing or coordinating with a hydrophilic moiety, coating with a first amphipathic organic compound, characterized in that said first amphipathic organic compound contains a hydrophilic moiety and a hydrophobic moiety and the hydrophilic moiety is adsorbed or coordinated with the core and the hydrophobic moiety thereby extends outwardly from the inorganic core and further coated with a second amphipathic organic compound wherein said second amphipathic compound contains hydrophobic and hydrophilic moiety and the hydropholic moiety associates with the outwardly extending hydrophobic moiety of said first amphipathic compound to form said wave absorbing composition.

2. The composition of claim 1, wherein the wave absorbing magnetic core particle has a diameter of less than 100 nm.

3. The composition of claim 1 wherein the amphipathic organic compound is a fatty acid selected from the group consisting of oleic, linoleic, linolenic, palmitic, myristic and arachidonic acid.

4. The composition of claim 1 wherein said second amphipathic organic compound is selected from the group consisting of phospholipids, sterol lipids and glycolipids.

5. The composition of claim 4 wherein the phospholipid is selected from the group consisting of phosphatidylcholine, phosphatidic acid, phosphatidylinositol, and phosphatidal ethonalamine.