November, 2009HOUSTON - (Business Wire) The National Institutes of Health (NIH) has awarded researchers at Rice University and the Texas Heart® Institute (THI) a $1 million Challenge Grant to refine cell-tracking nanotube technology that could make magnetic resonance imaging (MRI) up to 40 times more sensitive than existing MRIs and help guide adult stem cells within the human body to repair damaged hearts.
“This is an exciting and important step that will help meld two very promising technologies developed at our partnering institutions in a way that holds a lot of lifesaving promise,” said James Willerson, MD, THI president and a partner in the stem-cell research.
THI at St. Luke’s Episcopal Hospital is positioned to be the first to use the Stereotaxis Magnetic Navigation System to treat certain heart rhythm problems and to deliver stem cells to human hearts, pending approvals. The Stereotaxis is a new magnetic navigation system that uses image-guided, computerized equipment to achieve a safer, more efficient and more effective option for cardiology patients.
The grant will help perfect technology based on an ultrasensitive class of MRI contrast agents invented at Rice in 2005. Prescribed for about a third of all MRI patients today, contrast agents increase the sensitivity of MRI scans and make it easier for doctors to deliver a diagnosis. The most effective and common of these clinical agents contain a toxic metal called gadolinium, which is sequestered by wrapping the metal in organic molecules called chelates.
In Rice's new contrast agents, the gadolinium is encased inside hollow tubes of pure carbon, called nanotubes, to eliminate the metal's toxicity. These ‘gadonanotubes’ are at least 40 times more effective at boosting MRI signals than traditional gadolinium contrast agents.
"There's a great deal of interest in using stem cells to regenerate damaged heart tissue, but there hasn't been a really effective way to track the cells in vivo [within the body] and test their effectiveness," said gadonanotube inventor Lon Wilson, professor of chemistry at Rice. "Gadonanotubes may be what's needed because they are small enough to internally label individual cells with a large number of nanotubes and sensitive enough to track the cells in real time."
In addition, the gadonanotubes make the labeled cells highly magnetic so that it may be possible to steer the cells in vivo with an external magnetic field. This may aid in keeping the stem cells in a desired place for the several weeks it takes them to differentiate into heart muscle cells.
With the new grant, researchers at Rice and the THI will label stem cells with gadonanotubes and attempt to use the cells to regenerate damaged heart tissue. The team will use MRI to track the cells and judge their effectiveness.
“At THI, we are very excited to work in collaboration with Rice,” said Emerson Perin, MD, principal investigator on the Challenge Grant, director of clinical research for cardiovascular medicine at THI and medical director of THI’s Stem Cell Center. “It’s very exciting to utilize nanotechnology as a completely novel way for us to further understand stem cell therapy through imaging and tracking stem cells injected into the heart.”
“We’re very optimistic that this work may allow us to direct stem cells to a desired position and retain them in the heart with an external magnet,” said Dr. Willerson. “That would be a major milestone.”
Challenge Grants are part of the NIH’s stimulus funding initiative. The agency allotted $200 million from the American Recovery and Reinvestment Act (ARRA) for Challenge Grants, which promote advances in high-impact areas like regenerative medicine.
The NIH received a staggering 20,000 grant proposals for ARRA funding, and Wilson said the gadonanotube proposal was ranked within the top 2 percent. He also said Rice graduate student Lesa Tran deserves a large amount of the credit for that. Tran, a third-year PhD student, helped invent gadonanotubes while working as an undergraduate intern in Wilson’s lab. In her graduate work, Tran splits her time between Perin’s and Wilson’s labs, where she’s helped complete the groundwork for the NIH proposal under the direct supervision of Maria da Graça Cabreira, senior research scientist of the Stem Cell Center.
“This grant is a real milestone for the project, and it's a great testament to the hard work that Lesa and the rest of the team have dedicated to this project," Wilson said.
About Rice University
Located in Houston, Rice University is consistently ranked one of America's best teaching and research universities. Known for its "unconventional wisdom," Rice is distinguished by its: size -- 3,102 undergraduates and 2,237 graduate students; selectivity -- 12 applicants for each place in the freshman class; resources -- an undergraduate student-to-faculty ratio of 5-to-1; sixth largest endowment per student among American private research universities; residential college system, which builds communities that are both close-knit and diverse; and collaborative culture, which crosses disciplines, integrates teaching and research, and intermingles undergraduate and graduate work. Who Knew? http://explore.rice.edu/explore/Who_Knew.asp
About the Texas Heart® Institute
The Texas Heart Institute, founded by world-renowned cardiovascular surgeon Dr. Denton A. Cooley in 1962, is a nonprofit organization dedicated to reducing the devastating toll of cardiovascular disease through innovative and progressive programs in research, education and improved patient care. Together with its clinical partner, St. Luke’s Episcopal Hospital, it has been ranked among the top ten cardiovascular centers in the United States by U.S. News & World Report’s annual guide to “America’s Best Hospitals” for the past 19 years. The Texas Heart Institute is also affiliated with the University of Texas (UT) System, which promotes collaboration in cardiovascular research and education among UT and THI faculty at the Texas Heart Institute and other UT components.