In a groundbreaking development, scientists from the National Institute of Standards and Technology (NIST) have created a miniature device the size of a credit card that mimics the biology of the human heart. Dubbed the 'heart-on-a-chip', this technology has the potential to revolutionize the study of heart disease, the leading cause of death in the United States.

The heart-on-a-chip device has been designed to replicate the complex interactions between cells within a human heart. Traditional animal experiments often fail to accurately predict how diseases progress or how drugs will behave in the human body. As a result, scientists are working to develop more precise and realistic lab models of human organs.

One such model is the organ-on-a-chip, where specific cells are grown on a chip that imitates the physiological conditions of an organ in the body. Various organs, including the lungs, kidneys, and vagina, have already been successfully modeled on these chips. In the case of the heart-on-a-chip, researchers can study cardiac healing after injury, heart disease, and aid drug discovery.

The heart-on-a-chip models developed by the NIST team are unique in that they allow communication between cells through signaling molecules. By arranging cells on opposite sides of a porous membrane, scientists can observe how they react to different drugs introduced into the system. The next step for the team is to assess the behavior of these heart cells under normal and stress-induced conditions.

Furthermore, these organ chips can be linked together, creating a system where multiple organs can interact and be studied simultaneously. This capability enables scientists to explore how organs like the liver and heart interact after exposure to specific drugs, providing valuable insights into drug effects on the human body.

While this technology holds immense promise for drug development and precision medicine, there are still challenges to overcome. The heart cells used in these chips are typically derived from stem cells and often do not fully mature, resembling fetal cells rather than adult cells. Materials used in the chips, such as polydimethylsiloxane, also need refinement to ensure accurate drug testing.

In a recent review published in the journal Lab on a Chip, the NIST team highlighted the need for further improvements before organ-on-a-chip models can be widely implemented in preclinical drug tests. However, they believe that with continued development, these models could lead to a "paradigm shift" in drug development and testing.

The potential of organ-on-a-chip devices has not gone unnoticed by regulatory authorities. Last year, the Food and Drug Administration acknowledged their significance, permitting their use as alternatives to traditional animal testing as long as the generated data is robust enough.

By providing a more accurate representation of the human heart and its biology, the 'heart-on-a-chip' technology developed by the NIST team has the potential to accelerate drug development and make it safer and more precise. Although the road ahead requires further refinement, this innovative device brings hope for the future of understanding and treating heart disease.