Similar to how a picked lock indicates someone has broken into a building, the stiffening of a structure surrounding cells in the human body can indicate that cancer is invading other tissue. Monitoring changes to this structure, called the extracellular matrix, would give researchers another way to study the progression of disease. But detecting changes to the extracellular matrix is hard to do without damaging it.
Engineers have built a device that would allow disease specialists to load an extracellular matrix sample onto a platform and detect its stiffness through sound waves. It is the same concept as checking for damage in an airplane wing. There is a sound wave propagating through the material and a receiver on the other side. The way the wave propagates can indicate if there is any damage or defect without affecting the material itself.
Each tissue and organ has its own unique extracellular matrix, similar to how buildings on a street vary in structure depending on their purpose. The extracellular matrix also comes with “landlines,” or structural and chemical cues, that support communication between individual cells housed in the matrix. Researchers have tried stretching, compressing, or applying chemicals to samples of the extracellular matrix to measure this environment. But these methods also are prone to damaging the extracellular matrix.
The team developed a nondestructive way to study how the extracellular matrix responds to disease, toxic substances, or therapeutic drugs. The device is a lab-on-a-chip connected to a transmitter and receiver. After pouring the extracellular matrix and the cells it contains onto the platform, the transmitter generates an ultrasonic wave that propagates through the material and then triggers the receiver. The output is an electrical signal indicating the stiffness of the extracellular matrix.
The team demonstrated the device as a proof-of-concept with cancer cells contained in hydrogel, a material with a consistency similar to an extracellular matrix. The device could easily be scaled up to run many samples at once such as in an array. This would allow researchers to look at several different aspects of a disease simultaneously.