A lab-on-a-chip that can diagnose cancer and other diseases in their earliest stages . . . for a penny? That’s what researchers at the Stanford University School of Medicine (Stanford, CA) are working on. The technology could usher in a medical diagnostics revolution akin to low-cost genome sequencing, said Ron Davis, PhD, professor of biochemistry and genetics and Director of the Stanford Genome Technology Center. He is the senior author of a paper published online earlier this month in the Proceedings of the National Academy of Sciences.
|Image courtesy Zahra Koochak/Stanford University.|
A combination of microfluidics, electronics and inkjet printing technology, the two-part system comprises a clear silicone microfluidic chamber for housing cells and a reusable electronic strip underneath. A conventional inkjet printer can be used to print the electronic strip onto a flexible sheet of polyester using commercially available conductive nanoparticle ink.
“We designed it to eliminate the need for cleanroom facilities and trained personnel to fabricate such a device,” said Rahim Esfandyarpour, PhD, an engineering research associate at the genome center and lead author of the study. One chip can be produced in about 20 minutes, he said.
The multifunctional platform allows users to analyze different cell types without using fluorescent or magnetic labels, which are typically required to track cells, notes a press release on the Stanford University website. Instead, the chip separates cells based on their intrinsic electrical properties: When electricity is applied across the inkjet-printed strip, cells loaded into the microfluidic chamber get pulled in different directions depending on their "polarizability" in a process called dielectrophoresis. This label-free method to analyze cells greatly improves precision and cuts lengthy labeling processes, according to the researchers.
The tool is designed to handle small-volume samples for a variety of assays. The researchers showed the device can help capture single cells from a mix, isolate rare cells and count cells based on cell types. The cost of these multifunctional biochips is orders of magnitude lower than that of the individual technologies that perform each of those functions. A standalone flow cytometer machine, for example, which is used to sort and count cells, costs $100,000, without taking any operational costs into account.
The inexpensive lab-on-a-chip technology has the potential to democratize diagnostic capabilities around the world, especially in developing countries. Because of inferior access to early diagnostics, the survival rate of breast cancer patients is only 40% in low-income nations; it’s around 80% in the developed world. Other lethal diseases, such as malaria, tuberculosis and HIV, also occur in great frequency and result in bad patient outcomes in developing countries. Cheap diagnostics could be a life saver in these parts of the world.
“Enabling early detection of diseases is one of the greatest opportunities we have for developing effective treatments,” Esfandyarpour said. “Maybe $1 in the U.S. doesn’t count that much, but somewhere in the developing world, it’s a lot of money.”