Photo/IllutrationThe Asahi Shimbun

OSAKA--Japanese researchers have “grown” a heart in a laboratory using human induced pluripotent stem (iPS) cells, allowing them to study the side effects of new drugs more accurately.

As part of efforts to use iPS cells for developing drugs, scientists at Osaka University combined myocardial and other cells engineered from human iPS cells to create the pseudo-heart.

Anticancer agents, used to treat pulmonary, gastric and other cancers, carry a risk of causing adverse side effects to the heart.

To study these potential side effects in vitro, researchers need to create an environment similar to the inside of the human body by combining human cells.

A conventional technique to reproduce the heart, which has a three-dimensional structure, uses centrifugal force to pile up cells. One problem with this method is that the used cells become damaged during the reproduction process.

Mitsuru Akashi, a specially appointed professor of bioscience at Osaka University, and his colleagues developed a technique to pile up cells on certain target spots using filters.

With this method, the researchers succeeded in reproducing pseudo-heart tissue by mixing proteins into iPS cell-derived cells that develop into the cardiac muscle and blood vessel as a “glue” and by piling them up in 10 layers.

When the tissue was exposed to an anticancer drug, the beating rate of the artificial heart was nearly unchanged even when the concentration of the agent was 50 times the normal level.

According to the scientists, the adverse effect of the anticancer agent could be reduced drastically, because cells of the reproduced heart interacted with one another in a complex way as in a real heart.

The research team will work to improve the pseudo-heart so that it can be used for studies on the side effects of drugs.