When a heart attack occurs, the resulting dead heart tissue is replaced with scar tissue that's incapable of expanding and contracting. This means that the victim is left with a permanently weakened heart. Numerous studies are now looking at ways in which the dead tissue can instead be replaced with functioning cardiac tissue. While most of the lab-grown tissue created so far has used straight fibers as a base, scientists at Tel Aviv University recently had another idea – if the tissue is supposed to expand and contract, then why not make it using springy fibers?
Typically, heart tissue is grown in the lab (or in the patient) by "seeding" a three-dimensional nanoscale scaffold-like structure with cardiac cells, then letting those cells grow together. That structure serves the same purpose as the collagen "extracellular matrix" that naturally supports such cells in the heart.
Most previous studies have used growth structures that are are relatively straight. The Tel Aviv scientists, however, noticed that the extracellular matrix fibers in the hearts of rats were actually spiral-shaped. The researchers set about creating artificial versions of those fibers, using electrospinning techniques to create what looked like tiny telephone handset cords.
Tissue made by seeding those curly fibers with cardiac cells was indeed found to outperform tissue grown with straight fibers, when it came to functioning like natural heart tissue. More specifically, it reportedly "contracted with greater force and less mechanical resistance."
Clinical trials are planned to take place once the process for creating the springy heart tissue has been refined. The research is being led by Dr. Tal Dvir, who has previously created "heart patches" made with gold nanowires that allow the seeded cardiac cells to send electrical signals to one another.
