How do you mend a broken heart?

At the recent HSCI Public Forum on Stem Cells and Tissue Engineering, four scientists presented striking images that herald the future of regenerative medicine: tissue constructs creeping along a Petri dish, coils that tighten and release like a beating heart, and patches that fuse with surrounding tissue and blood vessels, creating a seamless repair in damaged organs – all created with the help of stem cells.

Moderated by David Mooney, PhD, Gordon McKay Professor of Bioengineering, the panel laid out a vision of using stem cells to grow replacement organs in the laboratory, repair damaged hearts, or correct life-threatening birth defects while the baby is still in the womb. The challenges in achieving this vision, however, remain significant.

Christine Mummery, PhD, Professor of Developmental Biology at the University of Utrecht and HSCI’s first visiting Radcliffe Institute Fellow, described her efforts to use stem cells to reverse the effects of a heart attack. Earlier experiments showed that stem cells could infuse, differentiate into cardiomyocytes (heart cells), and restore function to damaged hearts, but the effect was short-lived. The reason, she discovered, was that the cells did not maintain a structural organization that kept them working in the same direction. In order to make the repair more lasting, she is now turning to tissue engineering to help the grafted cells align properly in the heart. “I think the engineers have many of the solutions we are looking for,” Mummery said.

Harvard Assistant Professor of Biomedical Engineering Debra Auguste, PhD, also noted that stem cells need the right environment to differentiate into specialized tissue cells and thrive. Using microfluidics, or tiny laboratory systems for testing different solutions of nutrients and growth factors, Auguste is defining those optimal environments, which will then be translated into biomaterials that can support the use of stem cells in tissue grafts.

Interestingly, the application of stem cells for tissue engineering may be furthest along in repair of birth defects, where Harvard’s Assistant Professor of Surgery Dario Fauza, MD, is preparing for clinical trials (read more about Fauza’s work in Stem Cell Meets Patient). A significant portion of the panel discussion was centered on the challenges of working with the FDA, which has no formal structure for reviewing tissue engineered therapies. Considering the long path from the laboratory to the clinic, perhaps that is a welcome challenge.