Exosomes are nanosized extracellular vesicles (ranging from 30 to 120 nm) released from many cells that provide promising biomarkers for the noninvasive diagnosis of cancer. However, traditional exosome-isolation methods are tedious, nonstandardized, and require bulky instrumentation, thus limiting its clinical applications. In this paper, an anion-exchange (AE)-based isolation method was first proposed to isolate exosomes directly from plasma and cell-culture medium with AE magnetic beads within 30 min. Exosomes isolated with AE magnetic beads had higher recovery efficiency (>90%) and less protein impurities than those isolated by ultracentrifugation (UC). Prostate-cancer (PCa) exosomes in plasma were detected in a visual, label-free, and quantitative manner with aptamer-capped Fe3O4 nanoparticles for the first time. The linear range of PCa exosomes was estimated from 0.4 × 108 to 6.0 × 108 particles/mL with a detection limit of 3.58 × 106 particles/mL. The present study provides an efficient and practical approach for the rapid isolation and visible detection of exosomes, which is promising for the early diagnosis of PCa.

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A dielectrophoretic chip has been developed for extracellular vesicle (EV) isolation, which facilitates high-recovery efficiency (>83%) and high-purity EV isolation from plasma.

Immunological adjuvants are essential for successful cancer vaccination. However, traditional adjuvants have some limitations, such as lack of controllability and induction of systemic toxicity, which restrict their broad application. Here, we present a light-activable immunological adjuvant (LIA), which is composed of a hypoxia-responsive amphiphilic dendrimer nanoparticle loaded with chlorin e6. Under irradiation with near-infrared light, the LIA not only induces tumour cell lysis and tumour antigen release, but also promotes the structural transformation of 2-nitroimidazole containing dendrimer to 2-aminoimidazole containing dendrimer which can activate dendritic cells via the Toll-like receptor 7-mediated signaling pathway. The LIA efficiently inhibits both primary and abscopal tumour growth and induces strong antigen-specific immune memory effect to prevent tumour metastasis and recurrence in vivo. Furthermore, LIA localizes the immunological adjuvant effect at the tumour site. We demonstrate this light-activable immunological adjuvant offers a safe and potent platform for in situ cancer vaccination.