We present a microfluidic device for the capture and release of circulating exosomes from human blood. The exosome-specific dual-patterned immunofiltration (ExoDIF) device is composed of two distinct immuno-patterned layers, and is capable of enhancing the chance of binding between the antibody and exosomes by generating mechanical whirling, thus achieving high-throughput exosome isolation with high specificity. Moreover, follow-up recovery after the immuno-affinity based isolation, via cleavage of a linker, enables further downstream analysis. We verified the performance of the present device using MCF-7 secreted exosomes and found that both the concentration and proportion of exosome-sized vesicles were higher than in the samples obtained from the conventional exosome isolation kit. We then isolated exosomes from the human blood samples with our device to compare the exosome level between cancer patients and healthy donors. Cancer patients show a significantly higher exosome level with higher selectivity when validating the exosome-sized vesicles using both electron microscopy and nanoparticle tracking analysis. The captured exosomes from cancer patients also express abundant cancer-associated antigens, the epithelial cell adhesion molecule (EpCAM) on their surface. Our simple and rapid exosome recovery technique has huge potential to elucidate the function of exosomes in cancer patients and can thus be applied for various exosome-based cancer research studies.

Immunoaffinity based EV isolation technologies use antibodies targeting surface markers on EVs to provide higher isolation specificity and purity compared to existing approaches.

As the recognition between natural killer (NK) cells and cancer cells does not require antigen presentation, NK cells are being actively studied for use in adoptive cell therapies in the rapidly evolving armamentarium of cancer immunotherapy. In addition to utilizing NK cells, recent studies have shown that exosomes derived from NK cells also exhibit antitumor properties. Furthermore, these NK cell‐derived exosomes exhibit higher stability, greater modification potentials and less immunogenicity compared to NK cells. Therefore, technologies that allow highly sensitive and specific isolation of NK cells and NK cell‐derived exosomes can enable personalized NK‐mediated cancer therapeutics in the future. Here, a novel microfluidic system to collect patient‐specific NK cells and on‐chip biogenesis of NK‐exosomes is proposed. In a small cohort of non‐small cell lung cancer (NSCLC) patients, both NK cells and circulating tumor cells (CTCs) were isolated, and it is found NSCLC patients have high numbers of NK and NK‐exosomes compared with healthy donors, and these concentrations show a trend of positive and negative correlations with bloodborne CTC numbers, respectively. It is further demonstrated that the NK‐exosomes harvested from NK‐graphene oxide chip exhibit cytotoxic effect on CTCs. This versatile system is expected to be used for patient‐specific NK‐based immunotherapies along with CTCs for potential prognostic/diagnostic applications.

Melanoma is among the most aggressive cancers, and its rate of incidence continues to grow. Early detection of melanoma has been hampered due to the lack of promising markers for testing. Recent advances in liquid biopsy have proposed noninvasive alternatives for cancer diagnosis and monitoring. Circulating tumor cells (CTCs) and cancer‐exosomes are gaining influence as promising biomarkers because of their cancer‐associated molecular markers and signatures. However, technologies that offer the dual‐isolation of CTCs and exosomes using a single sample have not been thoroughly developed. The dual‐utilization OncoBean (DUO) device is conjugated with melanoma specific antibodies, MCAM and MCSP, enabling simultaneous CTC and exosome isolations. Using blood samples from patients, CTCs and exosomes are specifically isolated from a single sample and then undergo molecular profiling for comprehensive study. Melanoma patients have 0–17CTCs mL⁻¹ and 299 µg exosomal protein mL⁻¹ while healthy donors display fewer than 2CTCs and 75.6 µg of exosomes mL⁻¹, respectively. It is also demonstrated that both markers express melanoma‐associated genes using multiplex qRT‐PCR to test for expression pattern of a 96 gene panel. The dual isolation and molecular characterization will allow for further research into melanoma to identify viable markers for disease progression and treatment efficacy.