One physiological consequence of cancer and other diseases spreading throughout the body can be the hardening of the structure surrounding cells called the extracellular matrix. Scientists at Purdue University have now developed a new way to detect such changes through the use of sound waves, offering a potential new tool to track disease progression.

The stiffness of the extracellular matrix surrounding cells may alter in response to toxic substances, drugs and disease, and scientists are hopeful of tracking tiny changes to this structure as a way of monitoring patient health and the spread of disease. Possibilities have included applying chemicals to samples of the extracellular matrix, or stretching or compressing it to measure any changes within, but this has proven hard to do so without causing it damage.

The Purdue University scientists believe they have found a way around this, with a small "lab-on-a-chip" device. This consists of a transmitter that generates an ultrasonic wave, which is propagated through a sample poured onto the platform, and a piezoelectric receiver on the other end. The electrical signal that the receiver generates is shaped by the stiffness of the sample, and can therefore reveal changes to its structure.

“It’s the same concept as checking for damage in an airplane wing," says Rahim Rahimi, a Purdue assistant professor of materials engineering. "There’s a sound wave propagating through the material and a receiver on the other side. The way that the wave propagates can indicate if there’s any damage or defect without affecting the material itself."

The team put its lab-on-a-chip through its paces in experiments involving breast cancer cells embodied in a hydrogel, which was chosen for its similarity in consistency to an extracellular matrix. This revealed changes in the stiffness of the simulated tissue, and did so without inducing a toxic response in the cells or overheating the device.

According to the team, the device could be scaled up and used to analyze a number of samples at the same time, which would allow scientists to study different aspects of a disease. They have now moved into testing extracellular matrices based on collagen, the key structural protein in skin and other tissues.

A research paper describing the device was published in the journal Lab on a Chip, while you can hear from the scientists involved in the video below.

Lab-on-a-chip Ultrasonic Platform to Monitor Tissue Culture Stiffness

Source: Purdue University