Patent ID: 6541039
Filing Date: 2003-04-01
Classification: A61K,A61P

Abstract:
A method of hyperthermic treatment of a region of the body selected from the group consisting of hyperthermic tumor therapy, heat-induced lysis of a thrombus, and thermoablation of a target region, comprising:(a) accumulating in the region of the body a magnetic fluid comprising nanoscale particles suspended in a fluid medium, each particle having an iron oxide-containing core and at least two shells surrounding said core, (1) the innermost shell adjacent to the core being a shell that: (a) is formed from polycondensable silanes comprising at least one aminosilane and comprises groups that are positively charged or positively chargeable, and (b) is degraded by human or animal body tissue at such a low rate that adhesion of the core surrounded by the innermost shell with the surface of a cell through said positively charged or positively chargeable groups of the innermost shell and incorporation of the core into the interior of the cell are possible, and (2) the outer shell or shells comprising at least one species that: (a) is a biologically degradable polymer selected from (co)polymers based on &agr;-hydroxycarboxylic acids, polyols, polyacids, and carbohydrates optionally modified by carboxylic groups and comprises neutral and/or negatively charged groups so that the nanoscale particle has an overall neutral or negative charge from the outside of the particle, and (b) is degraded by human or animal body tissue to expose the underlying shell or shells at a rate which is higher than that for the innermost shell but is still low enough to ensure a sufficient distribution of a plurality of the nanoscale particles within a body tissue which has been infiltrated therewith; and (b) applying an alternating magnetic field to generate heat in the region by excitation of the iron oxide-containing cores of the particles, thereby causing the hyperthermic treatment.