Lab-on-a-Disc for Liquid Biopsy

Abstract

The lab-on-a-disc systems to isolate and detect liquid biopsy markers such as circulating tumor cells (CTCs) and cell-free DNA(cfDNA) or Extracellular vesicles (EVs) are developed and tested with clinical samples such as whole blood or urine from cancer patients. First, we will introduce the fluid-assisted separation technology (FAST), which enables ultrafast, uniform, clog-free, and highly efficient isolation of CTCs from whole blood with pressure drop much less than in conventional filtration. In addition, we demonstrate a fully automated cfDNA enrichment device integrating the plasma separation, sample lysis, DNA binding and elution on a single device. We used the lab-on-a-disc to isolate cfDNA from patients with non-small cell lung cancer and successfully detected epidermal growth factor receptor gene mutations (L858R, T790M) during targeted drug therapy. Next, we will present a rapid, label-free, and highly sensitive method for EVs isolation and quantification using a lab-on-a-disc integrated with nanofilters (Exodisc). Urinary EVs from prostate cancer patients could be automatically enriched within 30 min using a tabletop-sized centrifugal microfluidic system followed by molecular analysis or on-chip ELISA. As a proof of concept study, we analyzed androgen receptor splice variant 7 (AR-V7) which is associated with castration-resistant prostate cancer (CRPC) and resistance to anti-androgen therapy in the RNA isolated from the urine-derived extracellular vesicles (EVs) without the need for blood withdrawal. Further, the device also facilitates temporal monitoring of tumor progression within live mouse xenograft models over a period of 13 weeks whilst using minimal volume of weekly collected blood samples. Taken together, Exodisc is a powerful tool to provide a rapid, sensitive, and pointof-care-type method for extracting intact EVs from urine or small volumes of blood samples for disease diagnosis and monitoring. We believe that this revolutionary method can contribute to accelerate the acceptance of liquid biopsy-based cancer diagnostics as a standard practice in clinical settings.