AsianScientist (Jan. 14, 2019) – Monitoring the function of living, beating heart cells just got easier with an invention by scientists at the University of Tokyo, Tokyo Women’s Medical University and RIKEN in Japan. Their findings are published in the journal Nature Nanotechnology.
Cardiovascular disease are a leading cause of death worldwide. To better understand problems of the heart, scientists often make use of cardiomyocytes, or heart muscle cells, grown in petri dishes in the lab.
However, the hard surface of petri dishes and the rigid sensor probes used to study heart muscle cells impede the cells’ ability to beat in a coordinated fashion. This means that culture conditions may not accurately reflect the reality of heart muscle cells in the body.
In this study, scientists led by Professor Takao Someya at the University of Tokyo, Japan, have invented an electronic device—a soft nanomesh with embedded sensors—to closely monitor beating heart cells without affecting their behavior.
To create the nanomesh, the researchers used a process called electro-spinning to extrude ultrafine polyurethane strands into a flat sheet, similar to how some common 3D printers work. This spiderweb-like sheet was then coated in parylene, a type of plastic, to strengthen it.
The parylene on certain sections of the mesh was removed by a dry etching process with a stencil, and gold was subsequently applied to these areas to create sensor probes and communication wires. Additional parylene was applied to isolate the probes so their signals do not interfere with one another.
The researchers then took human stem cells, differentiated them into a sheet of heart muscle cells on a soft material called fibrin gel, and laid the nanomesh on top of the cell layer. They were able to record the propagation of signals which result from and trigger the beating of the heart muscle cells. These signals are known as an action or field potential and are extremely important when assessing the effect of drugs on the heart.
“Drug molecules need to be able to gain access to the cells. A solid sensor would either poorly distribute the drug or prevent it from reaching the cells altogether. So the porous nature of the nanomesh sensor was intentional and a driving force behind the whole idea,” said Lee. “Whether it’s for drug research, heart monitors or to reduce animal testing, I can’t wait to see this device produced and used in the field.”
The article can be found at: Lee et al. (2018) Ultrasoft Electronics to Monitor Dynamically Pulsing Cardiomyocytes.
Source: University of Tokyo; Photo: Someya Group.
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