Researchers at the University Of California (UC), Berkeley have successfully created human heart tissue in the lab using stem cells. This human heart tissue created in a chip replicates the mechanism of the entire heart and connective tissues associated with it which can help to test the efficacy and safety of cardiovascular drugs in human beings.
Need for Human Heart-on-a-Chip System
To bring a new medicine into the market with highest success rate and least side effects, it takes over a decade’s work and billions of dollars. Any new drug to become a viable medicine, it needs to go through a series of clinical trials tested on various subjects. It takes approximately $5 billion to develop a drug, 60% of that cost was used in research and development phase.
In spite of various phases of clinical trial, a high failure rate was associated with the use of animal models to test the efficacy of cardio vascular drugs. The failure is due to the difference in the biology between the species. For instance, the number and type of ion channels used by the heart cells to conduct electrical current differs in human beings and animals. As many drugs target these ion channels, the differences lead to insufficient and expensive experiments which provide inconclusive results about the toxicity of the drug on humans.
Thus, researchers at UC Berkeley decided to create a beating human heart tissue which can serve as a drug screening tool.
How is it created?
The research teams from UC Berkeley and Gladstone Institutes led by bioengineering professor, Kevin Healy have developed a network of pulsating heart muscle cells in an inch long silicone device which can replicate the mechanism of a human heart. This 3-D human tissue chip is created using induced pluripotent stem cells taken from adults. The researchers used adult stem cells and coaxed them to differentiate and form heart on a chip.
The researchers added the cardiac cells into a loading area in which the system’s confined geometry helps to align the cells in multiple layers, similar to the human heart. The lead author of the study, Anurag Mathur said that the system is not designed using simple cell culture bathed in medium. It is dynamic and mimics how the tissues in our bodies react to drugs.
How it work?
Within 24 hours of loading the cells in the chamber, the cardiac cells begins to beat on its own at a rate of 55-80 beats per minute which is a normal physiological rate for humans. Based on the changes of heart beat rate, the researchers were able to determine the response to these drugs. The baseline hear beat was consistent within 55-80 beats per minute and after administering isoproterenol, a drug used for slow heart beat, the beat rate of the heart tissue in the chip increased to 124 beats per minute within half an hour.
This system can serve as a drug screening tool to test the viability of cardiovascular drugs and ultimately they could replace the use of animal models in clinical trials. The researchers believe that this heart-on-a-chip system could be used for the following:
- To model human genetic diseases
- To test an individual’s reaction to a particular drug
- To model multi-organ interactions
- To link the heart and liver tissue and check if the drug works fine in the heart and later metabolizes in the liver without releasing toxicity
- To monitor the removal of metabolic wastes from the cells etc.
The study was published in the journal, Scientific Reports and the project is funded through an interagency collaboration by National Institutes of Health.