Doris Taylor wants to reload the matrix. A leading stem cell researcher at the University of Minnesota, Taylor is pioneering a new approach to transplantation, in which new hearts may one day be grown around the remaining scaffold, or matrix, of a cadaver heart, most likely from an animal.
I usually avoid covering basic or pie-in-the-sky research on CardioBrief. But an editor in London asked for some assistance covering Taylor’s presentations at the ACC so I checked out her talks here on Saturday. Taylor still has a long way to go, as she agrees along with everyone else, but her work now strikes me as a line of research worth following.
By using the matrix of animal hearts to grow human cells taken directly from the patient needing a new heart, Taylor hopes that her approach will overcome two of the biggest obstacles to transplant therapy: organ shortage and rejection.
Taylor’s research shows that the underlying matrix powerfully influences the fate of cells. In ways only dimly understood, the extracelleular matrix somehow imparts important functional clues to the cells. For instance, one fascinating finding is that cardiac derived progenitor cells will have a different morphology and pattern of gene expression depending on their matrix. A leading cardiologist, Anthony De Maria, said that this findings was “stunning.” Further, cardiac cells growing on the matrix can be taught to beat in unison, though as yet the power of the contractions is not comparable to a functional heart. In fact, the same cells will differ when applied to the matrix of the right ventricle or the left ventricle.
In addition to the matrix and cells, a functioning organ needs to be perfused. Taylor shows that arterial and vascular cells end up in the vasculature, and endothelial cells reline the entire vascular tree where they will inhibit throbus formation.
Another fascinating direction of Taylor’s research involves applying a matrix “patch” in place of infarcted tissue. In rats she has grown new cells on the matrix implanted inside the living rat to prevent functional decline after MI. “The patch begins to prevent negative remodeling” within days after experimental MI in rats, reports Taylor.
Taylor has worked with a large variety of animal and now human matrices, as well as different types of animal and human cell types. In some of her newest research, performed with collaborators in Spain, where the local laws favor organ donation, human cells have been grown on human matrices. Although this is an important part of her research, Taylor says it’s not the goal of her research, since using human matrices will hinder the growth of the technique.
No one knows when or if a total heart transplant using these techniques will be attempted, but, says Taylor, “I predict in 5 years a piece of heart will be transplanted.”
OK, Neo. Maybe you are “the One.”