Wear your heart on a chip – lab-grown heart chamber could help speed heart disease cures.
A research team led by Boston University has engineered a tiny living heart chamber replica that not only more accurately mimics the real organ, but will allow for better testing of new heart disease cures.
The miniature replica was built from a combination of nanoengineered parts, 3D printing technology and human heart tissue. Significantly, there are no springs or external power sources – just like a real heart, the device beats by itself and is contained on a chip not much larger than a postage stamp.
Longevity.Technology: According to the Centers for Disease Control and Prevention, someone dies of heart disease every 36 seconds [1]. Research is desperately needed, but hearts have an important function and can’t just be carried off to a lab for analysis. This tiny mechanical heart that is powered by actual cardiac cells might just prove to be the next-best thing.
The research team have nicknamed the gadget the miniPUMP (short for cardiac miniaturised Precision-enabled Unidirectional Microfluidic Pump) and are hopeful that the tech will speed up the drug development process, as well as opening the door for other lab-based organs, including lungs and kidneys.
“We can study disease progression in a way that hasn’t been possible before,” says Alice White, a BU College of Engineering professor and chair of mechanical engineering. “We chose to work on heart tissue because of its particularly complicated mechanics, but we showed that, when you take nanotechnology and marry it with tissue engineering, there’s potential for replicating this for multiple organs [2].”
“The heart experiences complex forces as it pumps blood through our bodies,” says Christopher Chen, a BU College of Engineering professor of biomedical engineering. “And while we know that heart muscle changes for the worse in response to abnormal forces – for example, due to high blood pressure or valve disease – it has been difficult to mimic and study these disease processes. This is why we wanted to build a miniaturized heart chamber [2].”
The miniPUMP has been built to act just like like a human heart ventricle, the muscular lower chamber that pumps the blood out from the heart and round the body.
The device consists of a thin 3D-printed plastic base, upon which are mounted tiny acrylic valves, tubes and the pump itself. The pump contains a scaffold made up of a series of linked concentric acrylic spirals which are seeded with live human cardiomyocytes (heart muscle cells) [3].
Like a real heart, the device beats on its own, driven by the live heart tissue which has been grown from stem cells. The cardiomyocytes expand and contract in unison, and as they do, the flexible scaffold moves with them, pumping liquid through the miniPUMP. The acrylic valves open and close to control the flow, and the tubes direct the fluid, just like our circulatory system.
Because the cardiomyocytes are obtained by reprogramming skin or blood cells into pluripotent stem cells which are then nudged into differentiating into heart cells, patients could have personalised miniPUMPs, made from their own cells. This would allow researchers to ascertain how different treatments might affect their hearts specifically.
“With this system, if I take cells from you, I can see how the drug would react in you, because these are your cells,” says Christos Michas, a postdoctoral researcher who designed and led the development of the miniPUMP as part of his PhD thesis.
“This system replicates better some of the function of the heart, but at the same time, gives us the flexibility of having different humans that it replicates. It’s a more predictive model to see what would happen in humans – without actually getting into humans [2].”
Michas says that because the miniPUMP could allow scientists to assess a new heart disease cures’ chances of success long before heading into clinical trials, the numbers of drug candidates failing trials due to harmful side effects would be reduced.
“At the very beginning, when we’re still playing with cells, we can introduce these devices and have more accurate predictions of what will happen in clinical trials,” says Michas. “It will also mean that the drugs might have fewer side effects [2].”
[1] https://www.cdc.gov/heartdisease/facts.htm
[2] https://www.bu.edu/articles/2022/new-miniature-heart-could-help-test-heart-disease-cures/
[3] https://www.science.org/doi/10.1126/sciadv.abm3791
