WPI Research is the research magazine of Worcester Polytechnic Institute. It contains news and features about graduate research in the arts and sciences, business, and engineering, along with notes about new grants, books, and faculty achievements.
Issue link: http://wpiresearch.epubxp.com/i/229254
notebook > STRINGING CELLS ON A THREAD TO REBUILD HEARTS DURING A HEART ATTACK, vessels that deliver blood to the heart are choked off. Deprived of oxygen, cardiac muscle dies, to be replaced by scar tissue. With sections of its muscle now unable to contract, the heart becomes a less effcient pump. A number of research teams are seeking ways to restore heart function by regenerating damaged tissue. One promising approach involves seeding the heart with human mesenchymal stem cells (hMSCs), which are derived from bone marrow. In work to date, it has been shown that this method can restore some heart function, but with existing delivery methods (injecting the cells into the bloodstream or directly into the heart muscle), only about 15 percent of the cells actually engraft. A research team at WPI has been working for several years on a more effective way to place stem cells exactly where they are needed and to give them a fghting chance to take hold. It involves growing the cells on microthreads made from fbrin, a protein involved in blood clotting. About the width of a human hair, the threads can be twisted into cable-like structures that mimic natural connective tissues. First developed in the lab of George Pins, PhD, associate professor of biomedical engineering, as a potential tool for repairing torn anterior cruciate ligaments in the knee, the microthreads were transformed by Pins and Glenn Gaudette, PhD, also an associate professor of biomedical engineering, into biological sutures that can be used to stich stem cells directly into wound sites and damaged tissues. In 2012 Gaudette and Pins founded VitaThreads to commercialize this invention; Adam Collette, vice president of product development, and Harry Wotton '94, CEO, are co-founders. In early 2013 the company was one of four fnalists in the Association of University Technology Managers annual international business plan contest. In the summer of 2013, Pins and Gaudette received a fve-year, $1.94 million award from the National Institutes of Health to continue to develop this innovative technology. In early studies the WPI team was able to grow up to 40,000 adult stem cells on each centimeter of a microthread suture. When the threads were stitched into an infarcted rat heart, more than 60 percent of the cells successfully engrafted into the cardiac muscle. With the NIH award, they will work to optimize the adhesion of stem cells to the microthreads by adjusting the composition of the threads and the process used to grow the cells. In addition to hMSCs, they will also work with induced pluripotent stem cells (iPSCs), which are adult human skin cells reprogrammed to act like stem cells, and evaluate the ability of each cell type to engraft and promote regeneration in an infarcted heart. The iPSCs will be developed in the lab of Michael Lafamme, MD, PhD, associate professor of pathology at the University of Washington and a leader in the feld of using induced pluripotent stem cells for cardiac regeneration. After stitching the cells into the damaged hearts, the team will use novel imaging and analytic techniques to determine whether the cells are promoting muscle regeneration and improving the mechanical function of the infarcted heart. Finally, they will add another class of cells, one that promotes blood vessel formation, to the microthreads to see if those cells, in combination with the stem cells, can augment the regeneration of the damaged cardiac muscle. < WPI researchers are using microthreads made from fbrin, above and left, as scaffolds for adult stem cells. The cells are grown on the threads (cells in the process of dividing appear in green in the photomicrograph). Bundles of threads, which mimic natural connective tissue, are stitched into damaged heart muscle, where they initiate regeneration. Worcester Polytechnic Institute > 3