Exosome Biomarker Profiling Using a Paper-Based Vertical Flow Assay
Pallarès-Rusiñol, Arnau (Universitat Autònoma de Barcelona. Departament de Química)
Marfà, Jennifer (Universitat Autònoma de Barcelona. Departament de Química)
Rossi, Rosanna (Universitat Autònoma de Barcelona. Departament de Química)
Martí, Mercè (Universitat Autònoma de Barcelona. Institut de Biotecnologia i de Biomedicina "Vicent Villar Palasí")
Pividori, María Isabel (Universitat Autònoma de Barcelona. Departament de Química)

Date:	2025
Abstract:	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.
Grants:	Agencia Estatal de Investigación PID2019-106625RB-I00 Agencia Estatal de Investigación PID2022-136453OB-I00 Agencia Estatal de Investigación PDC2022-133363-I00
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Exosome profiling ; Vertical flow assay ; Breast cancer ; Alkaline phosphatase ; Liquid biopsy ; Paper-based immunoassay ; Flow cytometry ; SDG 3 - Good Health and Well-being
Published in:	Biosensors, Vol. 15, Issue 10 (October 2025) , art. 694, ISSN 2079-6374

DOI: 10.3390/bios15100694
PMID: 41149346

15 p, 2.0 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Health sciences and biosciences > Institut de Biotecnologia i de Biomedicina (IBB)
Articles > Research articles
Articles > Published articles