Extracellular vesicles, including exosomes, are nanoscale vesicles that carry molecular information of parental cells. They are being pursued as biomarkers of cancers that are difficult to detect or serially follow. Here we present a compact sensor technology for rapid, on-site exosome screening. The sensor is based on an integrated magnetic-electrochemical assay: exosomes are immunomagnetically captured from patient samples, and profiled through electrochemical reaction. By combining magnetic enrichment and enzymatic amplification, the approach enables i) highly sensitive, cell-specific exosome detection, and ii) sensor miniaturization and scale-up for high throughput measurements. As a proof-of-concept, we implemented a portable, eight-channel device, and applied it to screen extracellular vesicles in plasma samples from ovarian cancer patients. The sensor allowed for the profiling of multiple protein markers simultaneously within an hour, outperforming conventional methods in assay sensitivity and speed.

Rationale:A rapid and massive influx of inflammatory cells occurs into ischemic area after myocardial infarction (MI), resulting in local release of cytokines and growth factors. Yet, the mechanisms regulating their production are not fully explored. The release of extracellular vesicles (EVs) in the interstitial space curbs important biological functions, including inflammation, and influences the development of cardiovascular diseases. To date, there is no evidence for in situ release of cardiac EVs after MI.Objective:The present study tested the hypothesis that local EV generation in the infarcted heart coordinates cardiac inflammation after MI.Methods and Results:Coronary artery ligation in mice transiently increases EV levels in the left ventricle when compared with sham animals. EVs from infarcted hearts were characterized as large vesicles (252±18 nm) expressing cardiomyocyte and endothelial markers and small EVs (118±4 nm) harboring exosomal markers, such as CD (cluster of differentiation) 63 and CD9. Cardiac large EVs generated after MI, but not small EVs or sham EVs, increased the release of IL (interleukin)-6, CCL (chemokine ligand) 2, and CCL7 from fluorescence-activated cell–sorted Ly6C+ cardiac monocytes. EVs of similar diameter were also isolated from fragments of interventricular septum obtained from patients undergoing aortic valve replacement, thus supporting the clinical relevance of our findings in mice.Conclusions:The present study demonstrates that acute MI transiently increases the generation of cardiac EVs characterized as both exosomes and microvesicles, originating mainly from cardiomyocytes and endothelial cells. EVs accumulating in the ischemic myocardium are rapidly taken up by infiltrating monocytes and regulate local inflammatory responses.

Sepsis is an often fatal condition that arises when the immune response to an infection causes widespread systemic organ injury. A critical unmet need in combating sepsis is the lack of accurate early biomarkers that produce actionable results in busy clinical settings. Here, we report the development of a point-of-care platform for rapid sepsis detection. Termed IBS (integrated biosensor for sepsis), our approach leverages i) the newly-found pathophysiological role of cytokine interleukin-3 (IL-3) in early sepsis, and ii) a hybrid magneto-electrochemical sensor for IL-3 detection. The developed platform produces test results within 1 hour from native blood samples, and detects IL-3 at a sensitivity of <10 pg/mL; this performance is >5-times faster and >10-times more sensitive than a current gold standard, enzyme-linked immunoadsorbent assay. Using clinical samples, we show that high plasma IL-3 levels are associated with high organ failure rate and thus greater risk of mortality, confirming the potential of IL-3 as an early diagnostic biomarker. Compact and fast, the IBS platform can be readily integrated into clinical workflows, enabling timely diagnosis and proactive treatment of sepsis.