摘要 |
<p>An ultrasonic imaging agent is produced by a continuous sonication processing of an aqueous solution of heat-denaturable biocompatible protein. The solution is carefully preheated to a temperature of incipient protein denaturation without forming insolubilized protein. A gaseous fluid, preferably air, is added to the solution. In the sonication, the air-containing solution is foamed, increasing the formation and concentration of microbubbles, and the solution is further heated to insolubilize a portion of the protein, thereby encapsulating the microbubbles and forming particulate microspheres.</p> |