New technology lets doctors diagnose cancer quickly from a droplet of blood

Scientists have developed a "lab-on-a-chip" that may allow doctors to detect cancer quickly from a droplet of blood or plasma, leading to timelier interventions and better outcomes for patients.

The ultrasensitive diagnostic device, developed by researchers at University of Kansas in the US, detects exosomes -- tiny parcels of biological information produced by tumour cells to stimulate tumour growth or metastasize.

"Historically, people thought exosomes were like 'trash bags' that cells could use to dump unwanted cellular contents," said Yong Zeng, an associate professor at KU. 

"But in the past decade, scientists realised they were quite useful for sending messages to recipient cells and communicating molecular information important in many biological functions," said Zeng. 

"Basically, tumours send out exosomes packaging active molecules that mirror the biological features of the parental cells. While all cells produce exosomes, tumour cells are really active compared to normal cells," he said.

The new lab-on-a-chip's key innovation is a 3D nanoengineering method that mixes and senses biological elements based on a herringbone pattern commonly found in nature, pushing exosomes into contact with the chip's sensing surface much more efficiently in a process called "mass transfer."

"People have developed smart ideas to improve mass transfer in microscale channels, but when particles are moving closer to the sensor surface, they're separated by a small gap of liquid that creates increasing hydrodynamic resistance," Zeng said.

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"Here, we developed a 3D nanoporous herringbone structure that can drain the liquid in that gap to bring the particles in hard contact with the surface where probes can recognize and capture them," he added.

Researchers tested the chip's design using clinical samples from ovarian cancer patients, finding the chip could detect the presence of cancer in a minuscule amount of plasma.

"Our collaborative studies continue to bear fruit and advance an area crucial in cancer research and patient care -- namely, innovative tools for early detection," said Andrew Godwin, KU Cancer Center Deputy Director.

"This area of study is especially important for cancers such as ovarian, given the vast majority of women are diagnosed at an advanced stage when, sadly, the disease is for the most part incurable," said Godwin.

The microfluidic chips developed at KU would be cheaper and easier to make than comparable designs, allowing for wider and less-costly testing for patients.

"What we created here is a 3D nanopatterning method without the need for any fancy nanofabrication equipment -- an undergraduate or even a high school student can do it in my lab," Zeng said. 

"This is so simple and low-cost it has great potential to translate into clinical settings," he said.