In a breakthrough effort, scientists at Max Planck Institute for Heart and Lung Research in Bad Nauheim, Germany, have build an artificial cardiac tissue using silk from the tropical tasar silkworm.

Because it is very difficult to regenerate damaged human heart muscle, the scientists successfully loaded cardiac muscle cells onto a three-dimensional scaffold, using silk produced by a tropical silkworm.

The collaborative study explained that scar tissues usually grow and replace damaged cardiac muscle cells. The Max Planck study is an attempt to seek an alternate method that could repair worn-out cardiac tissue. The idea is to grow replacement laboratory versions of  cardiac tissues that could provide replacement patches for repairing damaged cardiac muscle.

In collaboration with the Indian team, researchers produced coin-sized disks from the cocoon of the tasar silkworm or Antheraea mylitta. According to co-researcher Chinmoy Patra, the fiber produced by the tasar silkworm had several advantages over other substances that were tested earlier.

The surface has protein structures that facilitate the adhesion of heart muscle cells. It's also coarser than other silk fibers. This was seen as the primary reason why the muscle cells grew well on it and formed a three-dimensional tissue structure. The communication between the cells was intact and they beat synchronously over a period of 20 days, just like real heart muscle, said Felix Engel, lead researcher at the Max Planck Institute.

This is a much sought after breakthrough as research has long been on to seek an alternative device that could enable optimal cardiac output throughout the human lifecycle.

Whether natural or artificial in origin, all of the tested fibers had serious disadvantages, said Engel. They were either too brittle, were attacked by the immune system or did not enable the heart muscle cells to adhere correctly to the fibers. However, the scientists have now found a possible solution in Kharagpur, India, he noted.

The report said, The reconstruction of a three-dimensional structure poses a challenge here. Experiments have already been carried out with many different materials that could provide a scaffold substance for the loading of cardiac muscle cells.

The study explained that during the course of evolution, almost all of the body's own regeneration mechanisms in the heart become deactivated. This causes heart attacks resulting in dead cardiac cells which are irreversible in most cases. The result of such an eventuality almost leads to either a permanent damage or slow down of the heart's capacity to pump, considerably reducing a patient's quality of life.

The study is yet to reach clinical application.  Unlike in our study, which we carried out using rat cells, the problem of obtaining sufficient human cardiac cells as starting material has not yet been solved, said Engel. 

Engel, however, suggested that it could be possible to use a patient's own stem cells as the building blocks for constructing artificial cardiac tissues. This could help in preventing any sort of immune reaction. The study adds that the exact conversion of the stem cells into cardiac muscle cells, however, remains shrouded in mystery.