Ron Davis, PhD, professor of biochemistry and of genetics, and director of the Stanford Genome Technology Center predicts that at a production cost of only 1 cent per chip, this new technology could herald a medical diagnostics revolution similar to the one triggered by low cost genome sequencing.
The cheap ‘lab on a chip’ technology could potentially enhance diagnostic capabilities internationally, but especially in developing countries. The survival rate of breast cancer patients in low-income nations is only 40 percent – compared to 80 percent of such patients in developed nations. This is largely due to inferior access to early diagnostic systems. In developing countries, other deadly diseases such as tuberculosis, malaria and HIV also have bad patient outcomes and high incidence. As most diagnostic equipment costs thousands of dollars, better access to cheap equipment could help turn this around.
Esfandyarpour, an electrical engineer by training, believes that one of the biggest opportunities available for developing effective treatments is facilitating early detection of diseases. He added that although $1 in the U.S. does not count for much, it is a lot of money in the developing world.
The lab on a chip is a two-part system and consists of a combination of electronics, microfluidics and inkjet printing technology. The first part is a clear silicone microfluidic chamber that contains cells and an electronic strip that is reusable. A regular inkjet printer makes up the second part. The printer uses commercially available conductive nanoparticle ink to print the electronic strip onto a flexible sheet of polyester.
Esfandyarpour explained that the system was designed so that trained personnel are not required to manufacture the device. The process also eliminates the need for clean room facilities and a single chip can be produced in approximately 20 minutes.
As the device has been designed as a multifunctional platform, it has many different potential applications. One of these is that it allows users to analyze different cell types without using magnetic or fluorescent labels that are normally needed to track cells. The chip separates cells based on their intrinsic electrical properties instead. Cells that are loaded into the microfluidic chamber are pulled in different directions when an electric potential is applied across the strip that has been printed by the inkjet. The direction in which the cells are pulled depends on their “polarizability” and the process is known as dielectrophoresis. This method to analyze cells improves precision vastly and eliminates labeling processes that are often lengthy.
The tool is designed to process samples with a small volume for a variety of analyzes. The researchers demonstrated that the device could help capture single cells from a mix, count cells based on cell types and isolate rare cells. Individual technologies that perform each of those functions would each cost orders of magnitude more than the cost of these multifunctional biochips. Without considering any operational costs, a standalone flow cytometer, which is used to sort and count cells, would for example typically cost $100,000.
Davis explained that the team was motivated by finding ways to decrease the cost and export technology.
Diagnostics could be democratized by the low cost of the chips, similar to how low cost sequencing created a revolution in personalized medicine and health care. Cheap sequencing technology permits clinicians to identify specific mutations by sequencing tumor DNA. Personalized treatment plans can then be devised and recommended. The lab on a chip has a similar potential by detecting tumor cells that circulate in the bloodstream, thus helping to diagnose cancer early. Davis noted that the genome project changed the way in which medicine is done, and the team wants to continue building on that with different technologies that are both inexpensive and accessible.
Esfandyarpour is of the opinion that the technology has the potential to improve not only health care, but also to fast track both basic and applied research. It would potentially allow clinicians and scientists to analyze more cells in shorter periods, develop cost effective ways to diagnose diseases and manipulate stem cells to achieve efficient gene transfer. The team hopes the chip will result in a transformation in how instruments are used in the lab. Esfandyarpour is fairly sure that a window will open for researchers, as it makes life much easier for them — simply print it and use it.