Engineers and oncologists have teamed up to develop a microfluidic chip capable of capturing the body’s natural immune killer cells to harvest their exosomes. The results are published by Advanced Science.
Researchers at the Rogel Cancer Center and the University of Michigan College of Engineering have developed the first systematic way to trap natural killer cells and force them to release cancer-fighting exosomes. They are thousands of times smaller than natural killer cells (NK cells) and, therefore, are better able to penetrate the defense mechanisms of pathological cells.
A proof-of-concept study of blood samples from five patients with non-small cell lung cancer demonstrated that the new approach allows the capture of natural killer cells on a microfluidic chip and use them to “grow” NK exosomes.
Exosomes are small sacs of proteins and other molecules that are naturally secreted by almost all types of cells in the body. In this case, we wanted to expand our understanding of NK exosomes and try to use their potential for killing cancer.
Yun-Tae Kang, Ph.D., study co-author
Compared to NK cells, NK exosomes are more stable and easier to modify for therapeutic purposes. The study notes that the system can also aid in the diagnosis and monitoring of cancer.
One of the problems with NK cells is that after injection they do not penetrate into the tumor microenvironment. Exosomes derived from NK cells contain the same cancer-killing molecules, but they are much smaller and better penetrate tumors.
While a small amount of previous research has examined their ability to kill cancer cells, there was no systematic approach to capturing patient-derived NK cells and using them to create exosomes. Another advantage of them is that they are organic, natural for the human body.
The collection system combines three technologies. The researchers first captured NK cells on a graphene oxide microfluidic chip. The cells are then incubated, prompting them to release the exosomes. They are captured by tiny magnetic beads that are coated with specific antibodies. The beads are then removed from the chip and the NK exosomes are separated from them using a different process.