A Droplet-Microarray Platform for Multiplex Profiling of Breast Cancer Exosome Subtypes in Patients' Blood Plasma...

Breast cancer is highly heterogeneous, with distinct subtypes-luminal A, HER2-positive, and triple-negative-each exhibiting unique behaviors and treatment responses. Accurate identification of these subtypes is essential for guiding personalized therapies and improving outcomes. Exosomes, small extracellular vesicles secreted by tumor cells, have emerged as critical biomarkers for cancer diagnostics due to their pivotal role in intercellular communication and their rich molecular cargo reflective of cell origin. However, current exosome-based biosensors struggle to differentiate between breast cancer subtypes, limiting their effectiveness in precision medicine. To address this challenge, we have developed an innovative droplet-microarray platform integrated with a DNase I-assisted MoS₂ FRET aptasensor for multiplexed profiling of breast cancer exosome subtypes (luminal A, HER2-positive, and triple-negative). This platform targets three key protein biomarkers-HER2, MUC1, and CD44-leveraging the high specificity of aptamers and the sensitivity of DNase I-assisted signal amplification. Our approach enables high-resolution differentiation of breast tumor exosome profiles with an impressive limit of detection (LOD) of approximately 10² particles/mL. Application of this aptasensor to clinical samples demonstrated excellent predictive accuracy for breast cancer subtype discrimination (luminal A: AUC = 0.95; HER2-positive: AUC = 0.99; triple-negative: AUC = 0.90). By enabling precise identification of breast cancer subtypes, our approach holds promise for enhancing diagnostic accuracy and guiding personalized treatment strategies. This advancement represents a significant step forward in the application of exosome-based diagnostics in precision oncology.