August 28, 2006
Biomedical engineers at The University of Texas at Austin have used miniature particles to mark body cells whose accumulation within arteries could indicate a pending heart attack.
The researchers demonstrated the concept in mice by tagging macrophages, scavenger cells that ingest substances such as bacteria and cellular debris. When plaque builds up in arteries in the heart and elsewhere, macrophages accumulate within the plaque to ingest its fatty content. As a result, these macrophages can serve as a marker of the plaques’ location. Macrophages became of great interest recently when studies determined they concentrate at high levels in thin plaques within arteries near the heart. Those thin plaques are most likely to rupture and initiate a heart attack.
In research published in the journal Nanotechnology Aug. 28, Associate Professor Thomas Milner and graduate student Junghwan Oh took the first step to determine if macrophage activity can be easily tracked. In particular, the team demonstrated they could identify macrophages in the livers of mice after the macrophages ingested iron-based nanoparticles. Their study detected the macrophages by using an external magnetic field to shift the orientation of iron-based nanoparticles. Milner’s lab detected that shifting using ultrasound monitors.
To test the particles’ utility for cardiovascular imaging, the researchers are now conducting experiments using other animal models that permit visualization of nanoparticles trapped inside macrophages in arteries. These studies are also investigating alternative approaches to excite different types of nanoparticles, and will explore ways besides ultrasound to detect modified particles.
About UT's Cockrell School of Engineering:
The University of Texas at Austin's Cockrell School of Engineering ranks among the top six public engineering schools in the United States. With the nation's fourth highest number of faculty elected members of the National Academy of Engineering, the School's more than 7,000 students gain exposure to the nation's finest engineering practitioners. Appropriately, the School's logo, an embellished checkmark used by the first UT engineering dean to denote high quality student work, is the nation's oldest quality symbol. The School maintains a Web site at http://www.engr.utexas.edu