Microfluidic-based exosome isolation and highly sensitive aptamer exosome membrane protein detection for lung cancer diagnosis

• DOI: 10.1016/j.bios.2022.114487
• Publication Date: 2022-06-18T02:03:35Z
• Authors: Liang Zhao; Hong Wang; Jun Fu; Xia Wu; Xiao-ye Liang; Xue-yu Liu; Xue Wu; Liang-liang Cao; Zhen-yu Xu; Ming Dong
• Keywords: 0303 health sciences; 03 medical and health sciences; Lung Neoplasms; Microfluidics; Humans; Membrane Proteins; Biosensing Techniques; Aptamers, Nucleotide; Exosomes; 3. Good health

Non-invasive methods of detecting cancer by circulating exosomes are challenged by inefficient purification and identification. This study hereby proposed an automated centrifugal microfluidic disc system combined with functionalized membranes (Exo-CMDS) to isolate and enrich exosomes, which will then be processed by a novel aptamer fluorescence system (Exo-AFS) in order to detect the exosome surface proteins in an effective manner. Exo-CMDS features in highly qualified yields with optimal exosomal concentration of 5.1 × 109 particles/mL from trace amount of blood samples (<300 μL) in only 8 min, which truly accomplishes the exosome isolation and purification in one-step methods. Meanwhile, the limit of detection (LOD) of PD-L1 in Exo-AFS reaches as low as 1.58 × 105 particles/mL. In the trial of clinical samples, the diagnostic accuracy of lung cancer achieves 91% (95% CI: 79%-96%) in contrast to the exosome ELISA (area under the curve: 0.9378 versus 0.8733; 30 patients). Exo-CMDS and Exo-AFS display the precedence in the aspects of inexpensiveness, celerity, purity, sensitivity and specificity when compared with the traditional techniques. Such assays potentially grant a practicable way of detecting inchoate cancers and guiding immunotherapy in clinic.