BBC Science Focus
The breakthrough could have major implications in the study of heart disease
The month’s biggest science news. Researchers 3D print a working heart pump; tiny dinosaur relative ate insects; maize plants recruit wasp bodyguards as pest control; ultra-black deep-sea fish; photos from Solar Orbiter.
According to the British Heart Foundation, heart and circulatory diseases cause more than a quarter of all deaths in the UK; that’s nearly 170,000 deaths each year. In a new study, researchers at the University of Minnesota have created a functioning centimetre-scale human heart pump using 3D printing techniques, which could have major implications in the fight against heart disease.
In previous studies, researchers had tried to 3D print heart muscle cells, called cardiomyocytes, using pluripotent human stem cells – cells with the potential to develop into any type of cell in the body. They would programme these cells to form heart muscle cells, then with specialised 3D printers, deposit the cells within a scaffold structure called an extracellular matrix. Though promising, this method never produced cells dense enough for the heart muscle to function.
To get around this issue, the University of Minnesota researchers2
flipped the process around. “The stem cells were expanded to high cell densities in the structure first, and then we differentiated them to the heart muscle cells,” said Prof Brenda Ogle, the lead researcher and head of the Department of Biomedical Engineering in the University of Minnesota College of Science and Engineering.
Using this method, they found that they could reach high enough cell density within less than a month to allow the cells to beat together, just like a human heart.
“I couldn’t believe it when we looked at the dish in the lab and saw the whole thing contracting spontaneously and synchronously and able to move fluid,” said Ogle.
The heart muscle model is about 1.5 centimetres long and was specifically designed to fit into the abdominal cavity of a mouse for further study. It is like a closed sac featuring a fluid inlet and outlet, allowing researchers to measure how a heart moves blood within the body.
“We now have a model to track and trace what is happening at the cell and molecular level in pump structure that begins to approximate the human heart. We can introduce disease and damage into the model and then study the effects of medicines and other therapeutics,” explained Ogle. “All of this seems like a simple concept, but how you achieve this is quite complex. We see the potential and think that our new discovery could have a transformative effect on heart research.”
“I couldn’t believe it when we looked at the dish and saw the whole thing contracting spontaneously and synchronously”