A "heart-on-a-chip" could be used as a tool to screen life-saving cardiovascular drugs.
Scientists contained a network of pulsating cardiac muscle cells in an inch-long silicon device, allowing them to effectively model human heart tissue, the University of California, Berkeley reported. The innovation could allow for rapid and accurate testing of drug toxicity.
"It takes about $5 billion on average to develop a drug, and 60 percent of that figure comes from upfront costs in the research and development phase. Using a well-designed model of a human organ could significantly cut the cost and time of bringing a new drug to market," said study leader and bioengineering professor Kevin Healy.
The organ-on-a-chip could also help cut down on animal testing, which is often inaccurate due to significant differences in biology between species.
The heart cells were derived from human-induced pluripotent stem cells, and the 3-D structure of the chip was designed to be comparable to the geometry and spacing seen in natural human anatomy. Microfluidic channels on either side of the cell area also serve as blood vessels by mimicking the exchange by diffusion of nutrients and drugs. Within 24 hours of the heart cells being loaded into the chamber, they started beating at a similar rate to what would be seen in a human heart.
"This system is not a simple cell culture where tissue is being bathed in a static bath of liquid," said study lead author Anurag Mathur, a postdoctoral scholar in Healy's lab and a California Institute for Regenerative Medicine fellow. "We designed this system so that it is dynamic; it replicates how tissue in our bodies actually gets exposed to nutrients and drugs."
To test the effectiveness of the system, the researchers looked at the response of the heart cells to four commonly used cardiovascular drugs: "isoproterenol, E-4031, verapamil and metoprolol." They monitored changes in the heart tissue's beat and found the responses after exposure to the drugs were extremely predictable. The team noted the heart-on-a-chip could be developed to study genetic diseases or even to model multi-organ interactions.
"Linking heart and liver tissue would allow us to determine whether a drug that initially works fine in the heart might later be metabolized by the liver in a way that would be toxic," Healy said.
The breakthrough was published in a recent edition of the journal Scientific Reports.
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