Glycan Profiling in Small Extracellular Vesicles with a SERS Microfluidic Biosensor Identifies Early Malignant Development in Lung Cancer

Abstract Glycosylation is the most common post‐translational modification of proteins and regulates a myriad of fundamental biological processes under normal, and pathological conditions. Altered protein glycosylation is linked to malignant transformation, showing distinct glycopatterns that are associated with cancer initiation and progression by regulating tumor proliferation, invasion, metastasis, and therapeutic resistance. The glycopatterns of small extracellular vesicles (sEVs) released by cancer cells are promising candidates for cancer monitoring since they exhibit glycopatterns similar to their cell‐of‐origin. However, the clinical application of sEV glycans is challenging due to the limitations of current analytical technologies in tracking the trace amounts of sEVs specifically derived from tumors in circulation. Herein, a sEV GLYcan PHenotype (EV‐GLYPH) assay that utilizes a microfluidic platform integrated with surface‐enhanced Raman scattering for multiplex profiling of sEV glycans in non‐small cell lung cancer is clinically validated. For the first time, the EV‐GLYPH assay effectively identifies distinct sEV glycan signatures between non‐transformed and malignantly transformed lung cells. In a clinical study evaluated on 40 patients, the EV‐GLYPH assay successfully differentiates patients with early‐stage malignant lung nodules from benign lung nodules. These results reveal the potential to profile sEV glycans for noninvasive diagnostics and prognostics, opening up promising avenues for clinical applications and understanding the role of sEV glycosylation in lung cancer.