Janus Hydrogel-Based Fuel Stimulant Powered Amplification for Multiple Detections of miRNA Biomarkers in Gastric Cancer

MicroRNAs (miRNAs) circulating in body fluid have emerged as potential biomarkers for various diseases; however, owing to their low concentrations and short lengths (~22 nt), their clinical applications are still limited. Therefore, a highly sensitive and selective novel diagnostic platform for miRNA detection is required. Here, we present a hydrogel-based fuel stimulant-powered (FSP) amplification of fluorescent signals to detect circulating miRNAs from clinical samples of human serum. The advantage of this method is that it has high sensitivity as a fuel-assisted DNA cascade reaction that does not require temperature control and enzymes used for nucleic acid amplification. Further, we developed a Janus-type hydrogel for the simultaneous detection of the gastric cancer-associated miRNAs, miR-135b and miR-21. The detection limit of this hydrogel-based FSP amplification using synthetic miRNAs was estimated as < 10 fmol. We also validated the performance of this amplification process in in vitro and in vivo models and clinical samples. Therefore, we demonstrate that Janus hydrogel-based FSP amplification can selectively and sensitively identify the overexpression of miR-135b and miR-21 in clinical samples, thereby helping distinguish gastric cancer patients from healthy donors.