Scientists get closer to an artificial heart

Heart disease, a leading cause of death in many countries, is extremely deadly because the heart, unlike other organs, cannot repair itself after injury. Developing the human heart has long been the holy grail for cardiology researchers.

To build a human heart from scratch, researchers must replicate the unique structures that make up the heart. This includes recreating the helical shape that creates the torsional motion critical to pumping large volumes of blood out of the heart’s lower chambers, the ventricles, during the heart’s beating. This has so far proven elusive.

For centuries, doctors and scientists have gained a comprehensive understanding of the structure of the heart, but studying the purpose of the spiral muscle remains frustratingly difficult.Alabama, USA, 1969 University’s Edward Sullin argued that the helical alignment of the heart is important for the percentage of how much blood the ventricles pump with each contraction.

Now, bioengineers at the Harvard School of Engineering and Applied Sciences (SEAS) have developed the first biohybrid model of a human ventricle with beating heart cells arranged in a spiral. This advancement was made possible using a new technique used in textile manufacturing named Focused Rotary Jet Spinning (FRJS).

To test Sarin’s theory, SEAS researchers used the FRJS system to control the alignment of spun fibers on which cardiac cells were grown.

The first step in FRJS works like a cotton candy machine. A liquid polymer solution is placed in a container and forced out through a small opening by centrifugal force as the device rotates. As the solution leaves the container, the solvent evaporates and the polymer solidifies to form fibers. A focused air stream then controls the direction of the fibers and deposits them on the collector. By tilting and rotating the collector, the team found that the fibers in the stream aligned and twisted around the collector as it rotated, mimicking the helical structure of the heart muscle.

After rotation, the ventricles were seeded with human stem cell-derived cardiomyocytes, which are responsible for generating contractile force in the intact heart. Within about a week, several thin layers of beating tissue covered the scaffold and the cells followed the alignment of the underlying fibers. The beating ventricles mimicked the same twisting and squeezing movements that exist in the human heart.

Researchers have also shown that muscle alignment actually dramatically increases the amount of blood the ventricle can pump with each contraction. found to be superior to circumferentially aligned tissues.

The team also demonstrated that the process could be scaled up to the size of an actual human heart, and even larger. Harvard University’s Office of Technology Development has protected intellectual property associated with this project and is exploring commercialization opportunities.