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AssigneesMassachusetts Institute of Technology, The Penn State Research Foundation
InventorsSmadar Cohen, Alexander K. Andrianov, Margaret Wheatley, Harry R. Allcock, Robert S. Langer
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Compositions, methods for preparing and methods of using air-filled polymeric microcapsules for ultrasound imaging are disclosed. Air-encapsulating microcapsules are formed by ionotropically gelling synthetic polyelectrolytes such as poly(carboxylatophenoxy)phosphazene, poly(acrylic acid), poly(methacrylic acid) and methacrylic acid copolymers (Eudragit's) by contact with multivalent ions such as calcium ions. In the preferred embodiment, the average size of the microcapsules is less than seven .mu.m so that they are suitable for injection intravenously. The polymeric microcapsules are stable to imaging and display high echogenicity, both in vitro and in vivo. Due to their in vivo stability their potential application is extended beyond vascular imaging to liver and renal diseases, fallopian tube diseases, detecting and characterizing tumor masses and tissues, and measuring peripheral blood velocity. The microcapsules can optionally be linked with ligands that minimize tissue adhesion or that target the microcapsules to specific regions.
A microcapsule having a diameter of 700 microns or less formed of biocompatible hydrogel formed by crosslinking with a multivalent ion of a polymer selected from the group consisting of poly(phosphazenes), poly(acrylic acids), poly(methacrylic acids), copolymers of acrylic acid or methacrylic acid and polyvinyl ethers or poly(vinyl acetate), and sulfonated polystyrene, comprising a gas encapsulated therein in an amount effective for use as an imaging agent.
A method for preparing synthetic polymeric crosslinked microcapsules encapsulating imaging contrast agents comprising the steps of:
A method for ultrasonic imaging for use in medical procedures, comprising the steps of:
The method of claim 19 wherein the diameter of the microcapsule is between one and ten microns.
Dependencies are inferred from the claim text.