Scientists from Abertay University are growing tiny beating hearts from stem cells in the hope of finding a cure for a disease of the heart called hypertrophy. The teeny hearts are just 1 mm in diameter and beat around 30 times per minute.

Cardiac hypertrophy is associated with thickening of the heart muscle which ultimately leads to stiffening of the walls of the heart and abnormal valve function. Consequently, the flow of blood from the heart may be restricted. While some sufferers may be symptomless, others may experience chest pain, abnormal heart rhythms or even sudden death. Current treatments for the condition can ameliorate symptoms but they are not curative. Lead researcher Professor Nikolai Zhelev, however, hopes that his research will change this.

Zhelev’s team has been inducing disease in the miniature hearts by exposing them to certain chemicals which mimic the physiological conditions that stimulate cells to become hypertrophic. According to Zhelev, although human hearts have been successfully grown in dishes before, this is the first time that scientists have been able to induce disease in them.

The researchers are using these tiny diseased hearts as a testing platform for newly developed drugs in order to investigate their capacity to treat cardiac hypertrophy. By labeling particular molecules and observing their fate in the cells, the team has been able to elucidate which ones cause the hearts to become hypertrophic. Using this information, the scientists have been able to design compounds that target these particular molecules and thus prevent the onset of hypertrophy.

“We’ve tested a number of different compounds on these hearts- some of them entirely new ones that haven’t been tested in humans yet, which is why we’re testing them on these hearts we’ve grown in the lab,” said Zhelev in a news-release.

One of the drugs, however, was previously designed by Zhelev’s team as an anticancer agent and has just completed phase-II human clinical trials. The drug yielded very positive results in the human trial and in these lab tests. Zhelev found that similar trafficking pathways are shared by certain molecules in both cancerous cells and hypertrophic cells which prompted him to test this anticancer drug.

While some compounds trialed had detrimental effects, for example altering rhythm or stopping the hearts from beating altogether, others- such as the novel anticancer drug- managed to prevent the hearts from becoming hypertrophic.

Zhelev explains that they are still in the process of testing new drugs in the hope of finding compounds with increased efficacy and few side-effects. If they find a useful agent then they can submit it for pre-clinical tests.

“Although there is still a long way to go before the drugs become available commercially, we are extremely hopeful that we will one day be able to stop heart hypertrophy from developing in those at risk of the disease,” adds Zhelev.