Highly Efficient Isolation and Rapid Detection of Pancreatic Cancer-Derived Small Extracellular Vesicles by Specific Aggregation from Aptamer-Functionalized DNA Long Chains

Small extracellular vesicles (sEV) are increasingly reported as biomarkers for the early diagnosis of pancreatic cancer (PC), but the current techniques for isolation and detection of sEV rely on expensive instruments and tedious protocols. In this work, a facile and rapid sEV isolation and detection method (LAPT-sEViso) was developed, which is based on the specific aggregation of GPC-1-positive PC-derived sEV and an aptamer-functionalized DNA long chain produced by rolling circle amplification (RCA-APT). The LAPT-sEViso can efficiently isolate sEV from cell culture medium and serum, showing 45 times higher yield (5.5 × 10 6 particles mL –1 ), 1.1 times higher purity (1.66 × 10 10 particles mg –1 ) and 4.9 times higher recovery (80.9%) comparing to the traditional ultracentrifugation method, with only $1000 common instruments and $2.88 reagents/materials in 1 h. Moreover, after simple filtration and on-membrane ELISA, sEV concentration can be instrument-free detected with a limit of detection of 5.62 × 10 3 particles μL –1 (linear range from 5.0 × 10 3 to 5.0 × 10 7 μL –1 ). The LAPT-sEViso provides an efficient and practical approach for the rapid isolation and detection of sEV, providing a novel approach for the sEV-based liquid biopsy.