The prototype can perform the basic steps for processing a biopsy, relying on fluid transport instead of human hands to process the tissue. The team presented its initial results at the SPIE Photonics West conference and has filed a patent for the device.
‘This new process is expected to help the pathologist make a more rapid diagnosis and be able to determine more accurately how invasive the cancer has become, leading to improved prognosis,’ said Eric Seibel, a UW research professor of mechanical engineering and director of the department’s Human Photonics Laboratory.
The new instrumentation would essentially automate and streamline the manual, time-consuming process a pathology lab goes through to diagnose cancer. Currently, a pathologist takes a biopsy tissue sample, then sends it to the lab where it’s cut into thin slices, stained and put on slides, then analysed optically in 2D for abnormalities.
The UW’s technology would process and analyse whole tissue biopsies for 3D imaging, which offers a more complete picture of the cellular makeup of a tumour, said Ronnie Das, a UW postdoctoral researcher in bioengineering who is the lead author on a related paper.
‘As soon as you cut a piece of tissue, you lose information about it. If you can keep the original tissue biopsy intact, you can see the whole story of abnormal cell growth. You can also see connections, cell morphology and structure as it looks in the body,’ Das said in a statement.
The research team is building a thick, credit card-sized, flexible device out of silicon that allows a piece of tissue to pass through tiny channels and undergo a series of steps that replicate what happens on a much larger scale in a pathology lab.
The device harnesses the properties of microfluidics, which allows tissue to move and stop with ease through small channels without needing to apply a lot of external force. It also keeps clinicians from having to handle the tissue; instead, a tissue biopsy taken with a syringe needle could be deposited directly into the device to begin processing.
Researchers say this is the first time material larger than a single-celled organism has successfully moved in a microfluidic device. This could have implications across the sciences in automating analyses that usually are done by humans.
Das and Chris Burfeind, a UW undergraduate student in mechanical engineering, designed the device to be simple to manufacture and use. They first built a mould using a petri dish and Teflon tubes, then poured a viscous, silicon material into the mould. The result is a small, transparent instrument with seamless channels that are both curved and straight.
The researchers have used the instrument to process a tissue biopsy one step at a time, following the same steps as a pathology lab would. Next, they hope to combine all of the steps into a more robust device – including 3-D imaging – then build and optimise it for use in a lab.
Future iterations of the device could include layers of channels that would allow more analyses on a piece of tissue without adding more bulk to the device.