In this study, we present the utilization of urinary miRNAs derived from urinary EVs, including exosomes, captured by nanowires.

The nanowires could capture more than 99% of the EVs in urine, and the captured EVs had expression of the membrane proteins (CD63, CD81, and CD9).

Moreover, the nanowire-based method showed the ability to extract about 2500 species of urinary miRNAs.

Compared with serum miRNA species, the urinary miRNA species extracted by the nanowire-based method showed almost the same number of miRNA species, meaning that urine includes almost all human miRNAs. And, we used the identified urinary miRNA ensembles to distinguish lung cancer and noncancer subjects with an AUROC of 0.997; even when the lung cancer was stage I, an AUROC of 0.987 was achieved.

These results suggested that miRNAs are transferred via blood circulation and nonselectively filtered out by kidneys. Furthermore, we used identified miRNA ensembles to distinguish three classifications among brain tumor, lung cancer, and noncancer subjects with 86% sensitivity and 93% specificity.