A filter chip fabricated using standard soft-lithography techniques captures A549 cancer cells above 80% at 1 mL/min in PBS and >90% at 0.75 mL/min in spiked blood.
Mizzou has created a novel shape and arrangement of microfluidic posts for the passive, hydrodynamic separation and collection of circulating tumor cells. Instead of containing a single sized fluidic path for filtering, which limits the processing flow rate and could lead to failures by blockage, this new invention includes multiple flow resistant microfluidic paths around a main filtering path. Particles move radially outward during passage through the optimized curved channel due to centrifugal force. Cells are not damaged by this capture technique, so they are still viable for nuclear staining, PCR, etc. The device is also made from affordable materials and can be fabricated quickly.
While other microfluidic devices using microposts to capture circulating tumor cells have already emerged as promising tools for cancer detection, there has been little investigation into how the shape of filter structures can improve performance. This design enhances the cell interaction with optimized flow paths to improve capture efficiency and throughput.
STATE OF DEVELOPMENT
The optimal design was found using COMSOL Multiphysics 5.3a software. A filter chip was fabricated using standard soft-lithography techniques. Capture efficiency, repeatability, and reliability were evaluated in three experiments: micro beads of 7 micron-diameter in buffer solution, A549 human lung cancer cells in buffer solution, and A549 cancer cells in human blood. Micro beads at 1 ml/min yielded a capture efficiency of 95%. A549 cancer cells in PBS buffer at 100 cells/mL yielded a capture efficiency above 80% at 1 mL/min. Human blood spiked with A549 cancer cells yielded >90% capture efficiency at 0.75 mL/min.
• Prototype fabricated and tested
• Patent Pending: 16/830,617