Molecular Biosystems, Inc.

Edward G Jablonski

Karel J Lambert

Carl Hulle

Rolf Lohrmann

Kenneth L Hamilton

Sheila Benay Podell

Conventional ultrasonic imaging methods are described which involve the use of aqueous suspension of microspheres. These microspheres are further characterized as consisting of gas cores encapsulated by a protein shell which are formed in the presence of perfluoroalkane vapors. The presence of the vapor during formation changes the shell characteristics and thus protects the gas from being solubilized in the surrounding aqueous environment. In addition, the presence of the perfluoroalkane vapor during formation may also provide improved echogenic properties for vascular imaging applications.

Use of pressure resistant protein microspheres encapsulating gases as

Elastic protein microspheres, filled with water insoluble gases, have been produced by ultrasound and mechanical cavitation without the present of oxygen. The microspheres are highly echogenic. The microspheres exhibit greatly enhanced static pressure stability, up to 40 psig. The microspheres are resistant to coalescence and to expansion due to differential gas diffusion. The microspheres are resistant to collapse when suspended in a gas-depleted aqueous solution.

Method for making encapsulated gas microspheres from heat denatured

Ultrasonic imaging agents comprising an insoluble gas may be made by a new process of gas exchange. A solution is supersaturated with the insoluble gas and then contacted with a conventional air-filled microsphere suspension in order to effectuate a gas exchange process. The insoluble gas-containing microsphere exhibits increased pressure resistance and stability over microspheres in which the gas exchange was performed passively.

Gas-exchange method of making gas-filled microspheres

Ultrasonic imaging agents comprising an aqueous suspension of negatively buoyant aspherical microdroplets composed of a biocompatible liquid core encapsulated by a shell of amphiphilic biocompatible material are prepared by milling a mixture of a solution of the shell material and vaporized liquid and cooling the milled mixture to below the boiling point of the liquid.

Liquid core microdroplets for ultrasound imaging

Encapsulated gas microspheres useful as an ultrasonic imaging agent are made by: mixing an aqueous solution of a heat-denaturable protein with a gas, and passing the gas-solution mixture through a mill whereby the mixture is emulsified near the denaturation temperature of the protein and subjected to mechanical shearing and cavitation which causes the formation of gas bubbles in the 0.1 to 10 micron range, and the protein to locally denature and deposit at the gas-liquid interface to form the encapsulated microspheres.

Growing community of inventors

Escondido, CA, United States of America

Edward G Jablonski