Penetrating compacted and extensive blood clots has been one of the main challenges of vascular surgery. Various catheter-based devices have been invented and are in use today, but many patients present with plaques that are just too difficult even for the finest existing devices. Now, researchers at North Carolina State University and University of North Carolina at Chapel Hill have developed a new way to attack blood clots that involves special nanodroplets and an ultrasound catheter that activates them. The nanodroplets are made out of lipid spheres packed with low-boiling point liquid perfluorocarbons (PFCs). When the PFCs are released from the spheres, their tiny size allows them to get into the tiniest of crevices within a clot. Once there, a shower of ultrasound activates them to turn into expanding boiling microbubbles. Further ultrasound makes these microbubbles vibrate and break apart the clot mass. Clots that are not cracked fully through this mechanism still end up with significant structural deterioration that should allow for clot busters and other therapies to finish the job. “We found that the use of nanodroplets, ultrasound and drug treatment was the most effective, decreasing the size of the clot by 40%, plus or minus 9%,” said Xiaoning Jiang, corresponding author of the study appearing in Nature Microsystems and Nanoengineering. “Using the nanodroplets and ultrasound alone reduced the mass by 30%, plus or minus 8%. The next best treatment involved drug treatment, microbubbles, and ultrasound – and that reduced clot mass by only 17%, plus or minus 9%. All these tests were conducted with the same 30-minute treatment period.” The new technique has gone through in vitro testing but not clinical trials. Though the rate at which technologies are translated into medical devices gives us hope we may soon see this introduced in cath labs worldwide. Source
