Researchers at the University of Toronto have developed a new device to cultivate and test both atrial and ventricular cardiac tissue in the lab. The device, called Biowire II, consists of two elastic polymer wires which are positioned three millimeters apart, with a small band of cardiac tissue grown between them. A “training” regimen using electrical pulse stimulation is then applied for approximately six weeks, which promotes cardiac maturation and makes it more analogous to true tissue. As the tissue contracts, bending of the elastic polymer wires allows researchers to determine the force of the contractions.
While the group believes that the device will have applicability in a number of areas, they see it being particularly useful in the testing for potential drug candidates. A problem with in vitro testing of the cardiac toxicity of drugs is that the actual cardiac function of the tissue cannot be tested when looking at cells grown in a Petri dish. The Biowire II device provides the ability to test the functional effects of a drug on the tissue, providing a more comprehensive test of the drug candidate.
Lab-grown heart tissue, suspended between two strands made of an elastic polymer, beats inside the Biowire II. The platform both incubates the cells and measures how strongly they are contracting in real time. (Image: Yimu Zhao)
The group also foresees the application of the device in personalized medicine. In a test involving randomized samples from both healthy controls and patients with left ventricular hypertrophy, the lab used the device to determine which samples belonged to the patient group based on loss of contractility, which is an indication of the disease. With the ability to accurately model the cardiac function of individual patients, labs could study the progression of a disease in a particular patient or test a variety of potential treatments to determine which are most likely to be effective.
The device is currently being used by TARA Biosystems to test cardiac drugs on lab grown heart tissue for pharmaceutical companies. The researchers believe that because of the simplicity of the Biowire II system, it will be relatively easy to scale up the technology for more efficient and rapid testing.
Study in journal Cell: A Platform for Generation of Chamber-Specific Cardiac Tissues and Disease Modeling…