In a step toward better diagnosis and treatment of digestive conditions, such as inflammatory bowel disease, scientists report in ACS Biomaterials & Engineering that they have developed a first-of-its-kind collagen-based membrane for use in microchips. The membrane is more natural than others that are available, and it could allow organs-on-chips to more accurately replicate how healthy intestinal cells become diseased and how they react to drug treatments.

Traditionally, scientists have cultured cells on laboratory dishes and have used animal models to study disease and its potential treatments. But neither of these approaches fully mimic what occurs in the human body. Recently, researchers developed a way to grow living cells in microfluidic chips. Commonly called an organ-on-a-chip, each device is typically composed of a pair of flexible, translucent polymers or plastics that surround a porous membrane. Human cells extracted from an organ can be grown on the polymer or on the membrane. However, because the membrane itself is often made of plastic, it can disrupt cell interactions and skew the results. So, Abhinav Bhushan and colleagues at Illinois Institute of Technology sought to create a more natural membrane that would encourage the normal growth and development of human cells.

The researchers produced three types of microfluidic devices. One had no membrane, and the second had a plastic-derived membrane. For the third device, the research team used collagen to form the membrane. Collagen is one of the most common proteins in the body, and it helps form connective tissues. Then, they placed human colon cells in each device. After 5 days, microscopic evaluation revealed that colon cells on the collagen membrane were far more viable compared to those grown in the other devices. In addition, the cells grown on the collagen membrane were more differentiated. They also appeared to be integrating with the collagen fibers to remodel the microenvironment. The researchers concluded that using collagen-based membranes in organ-on-a-chip devices enhance the growth, viability and barrier function of human colon cells and that the method likely could be extended to cells from other organs.