A human heart in a laboratory

“You have to dream it and think it and speak it before you can do it.”

Dr. Doris Taylor, director of Regenerative Medicine at the Texas Heart Institute and a 1977 biology graduate of The W, said these words to public radio host Krista Tippett in a 2010 “On Being” interview. It was a broad-ranging discussion of cell therapies and Taylor’s vision of their potential to help heal diseases.

Her daring vision—that science can use nature’s own tools to help the body heal itself—is the core of research that has taken Taylor to positions at Duke University, the University of Minnesota’s Center for Cardiovascular Repair and to her current position as head of her groundbreaking research program in Texas.

Medical student Corbin E. Goerlich and Dr. Doris Taylor

In her labs on the ninth floor of the Denton A. Cooley Building in Houston, nestled in the heart of the largest medical complex in the world, she and her team of clinicians, engineers, biologists, medical residents, post-doctoral fellows and both undergraduate and graduate students are pushing the boundaries of the possible. Using animal and human cadaver hearts, they are attempting to create a new reality: one in which cell therapies can help a non-functioning heart regenerate, beat and thrive. Their work has the potential to transform the future of organ transplantation and treatments for heart disease.

To understand the research, one must first understand her previous work with stem cells – nature’s tool for repair. Stem cells are found throughout our bodies, in blood, bone, tissues. Throughout life they either self-replicate or become specialized (differentiated) cells, such as heart cells. They are nature’s way of helping tissues repair. Stem cell therapy, using adult stem cells, takes advantage of the fact that these cells regenerate and differentiate, harnessing that potential to treat the underlying disease rather than simply its symptoms. In 1998 this was a radical concept. Then she and her colleagues at Duke showed that you could repair the function of damaged hearts using stem cells from muscle or bone. Today, clinical trials happen world wide using stem cells for heart repair. In 2008, Taylor again made national news, from The New York Times to Oprah, for a deceptively simple but radical idea. In her lab at the University of Minnesota, she proved that her team could take an animal heart, strip it of all cellular matter, and leave a framework that could be re-cellularized using immature cells.

"Ghost Hearts" in Dr. Taylor's lab.

This “ghost heart” became a scaffold that allowed her team to re-seed the framework and create a beating rat heart in 2008. With her successive research, a ghost heart holds the potential for growing a fully functioning human heart in the lab. Taylor’s team is not there yet, but they are making progress. In her Texas lab, there are rat, rabbit and pig hearts, and an occasional human heart, in various stages of de- and re-cellularization. Hooked to a left ventricular assist device, one porcine heart pumps regularly. The goal is to produce a functioning heart capable of beating continuously on its own, one that would not cause rejection issues in a transplanted human.

It’s not an easy or inexpensive undertaking. The heart has billions of cells that have to beat in a perfectly timed rhythm. Acquiring the adult stem cells to grow and ultimately accomplish what a native heart does is a daunting undertaking. But Taylor is confident it can be done. A more immediate possibility, however, is developing a patch for a damaged heart. In her lab, viewed through a microscope, one can see a patch sample beat rhythmically, holding promise for repairing parts of a diseased heart.

Finding the stem cells and specialized equipment needed to conduct the scope of Taylor’s regenerative research can be challenging. “Funding is the lowest in my lifetime,” she said. “Technologically, we know how to make a heart. It’s a matter of having the right cells, and it takes hundreds of billions of cells for a heart. We believe we can build it, we will.”

Sometimes her lab gets cells from blood banks, Taylor explained. “We ask donors to consent to let us harvest cells from the filters used during plasma donations, for example. We try to take advantage of existing technologies.” Sometimes, the cells are purchased. Millions are stored at THI in a state of the art biosafety level 2 facility. Taylor is director of that facility, also housed on the ninth floor.

If her team can build, rather than buy more expensive equipment, they do. There are homemade Plexiglas chambers housing organs, some with the edges duct-taped. Other pieces of equipment may cost up to a million dollars. Taylor believes in finding ways to accomplish her goals, even if they are not easy.

Dr. Doris Taylor '77

If she seems driven, she is. As she sees it, her calling is building tissues and organs for people who need them most, using the tools that nature provides. It is a calling of caring. In part, she believes her work is fueled by the fact that she saw her father die of cancer when she was 6 years old. In part, it’s because she saw her twin brother suffer from cerebral palsy until he died of cancer just over a year ago. “I don’t want to see anyone else suffer that kind of pain,” she said.

Growing up in Columbus in a single-parent home, Taylor said she was taught that she could accomplish anything. Her mother was a librarian and encouraged her children to explore. “I would get up on Saturday mornings trying to figure out what didn’t exist that I needed to invent,” she said. When she began her studies at The W as a residential student, she said she didn’t consider herself remarkable in any way. Her professors, however, saw something else.

“Having people like Nora Howell and Dr. Jon Fortman and Dr. Bruce Lacey and Dr. Carl Doumit who were engaged with us and who taught us that it wasn’t just about school—it was about life—that helped us get ready for life,” she said. “I learned some lessons that I’m really proud of.”

Howell, in particular, encouraged Taylor’s scientific bent. “Mrs. Howell said, ‘Why don’t you consider working at a lab?’ And I thought, ‘That sounds so boring.’ What she saw that I didn’t, and didn’t appreciate at the time, was that I loved to ask questions. I never met a rule that I didn’t want to think about breaking, and I’m curious about everything. ‘Why?’ is my favorite question.”

Her career, Taylor said jokingly, can be ‘blamed’ on Mrs. Howell. “She recognized something I had no idea would become my path and my passion and would allow me to make a difference in the world, hopefully, and bring together cutting-edge information in new ways. What’s not to love?”

Taylor credits The W as one of the major influences in her life. “I learned more about how to think as an undergraduate at The W than I did as a graduate student. Having that curiosity sated by amazing professors as an undergraduate made me able to bring a level of sophistication about thinking to graduate school.” She said she was also surrounded by strong women who became role models, teaching her that it was OK to question and to challenge. “It was a level of empowerment I’m not sure I could have gotten at any other school.”

Now decades into research that has earned her international recognition, Taylor knows there is much work still to do. She thinks ahead to her legacy and said, “I hope I’ll be remembered as a contributor to the field of regenerative medicine, as someone who was involved from the early days of cell therapy and for opening a door in the organ transplantation field. If these bioartificial organs work the way I think they will, I believe we’ll be remembered for making that possible.

“Mostly I’d like to be remembered for being a caring, compassionate person, who made her mom proud.”