Circulating tumor
cells (CTCs) are essential biomarkers for cancer
diagnosis. Although various devices have been designed to detect,
enumerate, and isolate CTCs from blood, some of these devices could
have some drawbacks, such as the requirement of labeling, long process
time, and high cost. Here, we present a microfluidic device based
on the concept of “hydrodynamic cavitation-on-chip (HCOC)”,
which can detect CTCs in the order of minutes. The working principle
relies on the difference of the required inlet pressure for cavitation
inception of working fluids when they pass through the microfluidic
device. The interface among the solid/floating particles, liquid,
and vapor phases plays an important role in the strength of the fluid
to withstand the rupture and cavitation formation. To this end, four
experimental groups, including the “cell culture medium”,
“medium + Jurkat cells”, “medium + Jurkat
cells + CTCs”, and “medium + CTCs”, were
tested as a proof of concept with two sets of fabricated microfluidic
chips with the same geometrical dimensions, in which one set contained
structural sidewall roughness elements. Jurkat cells were used to
mimic white blood cells, and MDA-MB-231 cells were spiked into the
medium as CTCs. Accordingly, the group with CTCs led to detectable
earlier cavitation inception. Additionally, the effect of the CTC
concentration on cavitation inception and the effect of the presence
of sidewall roughness elements on the earlier inception were evaluated.
Furthermore, CTC detection tests were performed with cancer cell lines
spiked in blood samples from healthy donors. The results showed that
this approach, HCOC, could be a potential approach to detect the presence
of CTCs based on cavitation phenomenon and offer a cheap, user-friendly,
and rapid tool with no requirement for any biomarker or extensive
films acting as a biosensor. This approach also possesses straightforward
application procedures to be employed for detection of CTCs.
