Exosome Biomarker Profiling Using a Paper-Based Vertical Flow Assay

Exosomes are nanoscale extracellular vesicles that carry valuable biomolecular information. However, their characterization still depends on complex and costly techniques such as flow cytometry. In this study, a paper-based Vertical Flow Assay (VFA) specifically designed for the detection and profil...

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Detalles Bibliográficos
Autores: Pallarès-Rusiñol, Arnau|||0000-0001-9990-148X, Marfà, Jennifer|||0000-0001-5321-3841, Rossi, Rosanna|||0000-0002-3656-2908, Martí, Mercè|||0000-0002-1846-0043, Pividori, María Isabel|||0000-0002-5266-7873
Tipo de recurso: artículo
Fecha de publicación:2025
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:322412
Acceso en línea:https://ddd.uab.cat/record/322412
https://dx.doi.org/urn:doi:10.3390/bios15100694
Access Level:acceso abierto
Palabra clave:Exosome profiling
Vertical flow assay
Breast cancer
Alkaline phosphatase
Liquid biopsy
Paper-based immunoassay
Flow cytometry
SDG 3 - Good Health and Well-being
Descripción
Sumario:Exosomes are nanoscale extracellular vesicles that carry valuable biomolecular information. However, their characterization still depends on complex and costly techniques such as flow cytometry. In this study, a paper-based Vertical Flow Assay (VFA) specifically designed for the detection and profiling of exosomes derived from metastatic breast cancer cell lines is presented. The assay operates in an ELISA-like format, targeting exosomal surface proteins (CD9, CD63, CD81, and EGFR1) with specific antibodies and a secondary antibody conjugated to alkaline phosphatase. Upon reaction with the NBT/BCIP substrate, an insoluble indigo precipitate forms on the nitrocellulose membrane, generating a visual signal that can be further quantified by smartphone imaging. The VFA was optimized for membrane type, pore size, and blocking agents, reaching a detection limit of ~6 × 107 exosomes µL-1 in less than 20 min. Comparative studies with bead-based flow cytometry confirmed consistent biomarker expression profiles, demonstrating the reliability of the method. By enabling exosome biomarker profiling in a simplified and low-cost format, this approach provides a promising alternative to flow cytometry and other applications required for exosome characterization.