Isolation of Tumor Derived Exosomes Via Radial Flow Microfluidic Chip with “Click” Chemistry

In non-small lung cancer (NSLC), liquid biopsy is an attractive approach in early detection and dynamic real-time monitoring of the tumor. However, liquid biopsy typically lacks specificity and status of metastatic progression. To that end, we present a radial flow microfluidic device for the isolation of tumor derived exosomes (TDEs) expressing the epithelial cell adhesion molecule (EpCAM). Our device utilizes the inverse electron demand Diels-Alder (IEDDA) “click” chemistry reaction, along with a cleavable disulfide bond for sample release. From the many IEDDA reagents, the copper-free tetrazine and trans-cyclooctene (TCO) combination were used. Here, tetrazine conjugated antibodies were formulated with antibody markers which allowed rapid binding to a TCO functionalized device. Tetrazine modified epithelial cell adhesion molecule (^TzEpCAM) and CD63 (^TzCD63) antibodies were chosen to study TDEs in NSLC. Our ^TzEpCAM and ^TzCD63 antibodies solutions were then evaluated on two different cell lines: H1650 (high EpCAM expression) and A549 (low EpCAM expression). From this, our platform performed exceptionally well, revealing the specific isolation of EpCAM expressed exosomes in both H1650 and A549 cell lines. This specificity reveals that the radial flow microfluidic device coupled with the IEDDA “click” chemistry, has potential for early diagnosis and prognosis of NSLC, which is essential in preventing progressing lesions and improving patient survival.