Engineering the Heart - Damaged Heart Muscle Could Use Stem Cell Patch
Five Question Interview with Nenad Bursac
Nenad Bursac is an assistant professor in biomedical engineering who works with stem cells, tissue engineering and biomaterials to find a way to patch and repair the damage created by a heart attack.
Q - How did you get from electrical engineering to heart muscles?
I was always fascinated by the heart as an extremely complex and powerful, and yet delicate, organ. The heart is both an electrical and mechanical device and I feel it was natural for me to go from electrical engineering to studying electrical phenomena in the heart.
Q - What does a heart attack do to the heart muscle, and why does it need to be repaired?
During a heart attack, a portion of the heart muscle becomes irreversibly damaged and dies. The rest of the heart struggles to compensate for the function of this missing part and this excessive work can create more tissue damage and lead to serious complications, including death. Ideally, we would like to replace injured muscle tissue with a new and healthy heart muscle patch before more damage occurs.
Q - What’s so special about stem cells? Couldn’t you just use the patient’s own heart muscle to make repairs?
Patient’s own heart muscle cells will generally not divide in a sufficient number to replace the damaged part of the muscle. And if we took a larger part of the patient’s own heart muscle we would make more damage in another area, and things would only become worse. Therefore, we need an external and abundant source of cells for heart muscle repair, and a lot of research effort is ongoing to identify what that source could be. Ideally, stem cells have the potential to be this cell source for the repair of heart damage as they can be proliferated in a dish to large quantities and then potentially steered towards becoming heart cells.
Q - What kind of stem cells are you using in your research?
We are using different kinds of stem cells including those derived from human and rat bone marrow, rat skeletal muscle, as well as different types of mouse embryonic stem cells.
Q - Why can’t you just grow a new heart in a dish or something?
In order to grow an entire heart in a dish, we would also need to build a scaffold made of supporting cells and other structures that normally exist in the heart. That is a very complex and currently undoable task. For example, the heart is very active metabolically and needs a lot of small and large blood vessels woven throughout its tissues. These vessels are essential to keep muscle and other cells in the heart alive by supplying the necessary nutrients and oxygen and removing the damaging waste products. Currently, there are no tissue engineering methods to build functional blood vessels that would support the growth of thick and viable muscle tissues.