Highly Effective Detection of Exosomal miRNAs in Plasma Using Liposome-Mediated Transfection CRISPR/Cas13a

Exosomal miRNAs play a critical role in cancer biology and could be potential biomarkers for cancer diagnosis. However, due to the low abundance of miRNAs in the exosomes, recognizing and detecting disease-associated exosomal miRNAs in an easy-to-operate way remain a challenge. Herein, we used a liposome-mediated membrane fusion strategy (MFS) to transfect CRISPR/Cas13a into exosomes, termed MFS-CRISPR, directly measuring exosomal miRNAs in plasma. Using the MFS-CRISPR platform for detection of the exosomal miR-21, we achieve a linear range spanning four orders of magnitude (10(4)-10(8) particles/mL) and the method is able to detect the exosomal miR-21 in as low as 1.2 x 10(3) particles/mL. The liposome-mediated MFS could confine fluorescent signals in fused vesicles, which can be used for exosome heterogeneity analysis. Moreover, MFS-CRISPR assay was evaluated by measuring clinical samples, and the difference of miR-21 expression of breast cancer patients and healthy donors was significant. Because of high sensitivity and simplicity, the proposed method could have promising clinical potential for cancer diagnosis and treatment monitoring.

Automated summary

Exosomal miRNAs have a critical role in cancer biology and may serve as potential biomarkers for cancer diagnosis. However, detecting disease-associated exosomal miRNAs in an easy-to-operate manner is challenging due to their low abundance. In this study, a liposome-mediated membrane fusion strategy (MFS) called MFS-CRISPR was used to directly measure exosomal miRNAs in plasma. The MFS-CRISPR platform exhibited a linear detection range from 10(4) to 10(8) particles/mL and could detect exosomal miR-21 at a low concentration of 1.2 x 10(3) particles/mL. The proposed method showed promising clinical potential for cancer diagnosis and treatment monitoring due to its high sensitivity and simplicity.