title: Digital Detection of Exosomes by Interferometric Imaging.
abstract: Exosomes, which are membranous nanovesicles, are actively released by cells and have been attributed to roles in cell-cell communication, cancer metastasis, and early disease diagnostics. The small size (30-100 nm) along with low refractive index contrast of exosomes makes direct characterization and phenotypical classification very difficult. In this work we present a method based on Single Particle Interferometric Reflectance Imaging Sensor (SP-IRIS) that allows multiplexed phenotyping and digital counting of various populations of individual exosomes (>50 nm) captured on a microarray-based solid phase chip. We demonstrate these characterization concepts using purified exosomes from a HEK 293 cell culture. As a demonstration of clinical utility, we characterize exosomes directly from human cerebrospinal fluid (hCSF). Our interferometric imaging method could capture, from a very small hCSF volume (20 uL), nanoparticles that have a size compatible with exosomes, using antibodies directed against tetraspanins. With this unprecedented capability, we foresee revolutionary implications in the clinical field with improvements in diagnosis and stratification of patients affected by different disorders.
authors.affiliation: Nexgen Arrays, Boston, Massachusetts 02215, USA.
authors.forename: George G
authors.initials: GG
authors.lastname: Daaboul
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Chimica del Riconoscimento Molecolare (ICRM), Milano, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Gagni
authors.affiliation: Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Benussi
authors.affiliation: Nanoscience Laboratory, Department of Physics, University of Trento, Povo (TN) Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Bettotti
authors.affiliation: Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
authors.forename: Miriam
authors.initials: M
authors.lastname: Ciani
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Chimica del Riconoscimento Molecolare (ICRM), Milano, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Cretich
authors.affiliation: Nexgen Arrays, Boston, Massachusetts 02215, USA.
authors.forename: David S
authors.initials: DS
authors.lastname: Freedman
authors.affiliation: Molecular Markers Laboratory, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Ghidoni
authors.affiliation: Department of Electrical and Electronics Engineering, Bahçeşehir University, Istanbul, Turkey.
authors.forename: Ayca Yalcin
authors.initials: AY
authors.lastname: Ozkumur
authors.affiliation: Nanoscience Laboratory, Department of Physics, University of Trento, Povo (TN) Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Piotto
authors.affiliation: Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Prosperi
authors.affiliation: Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Milano, Italy.
authors.forename: Benedetta
authors.initials: B
authors.lastname: Santini
authors.affiliation: Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, USA.
authors.forename: M Selim
authors.initials: MS
authors.lastname: Ünlü
authors.affiliation: Consiglio Nazionale delle Ricerche, Istituto di Chimica del Riconoscimento Molecolare (ICRM), Milano, Italy.
authors.forename: Marcella
authors.initials: M
authors.lastname: Chiari
mesh_terms: D002555:Cerebrospinal Fluid / Q000737:chemistry*; D055354:Exosomes / Q000737:chemistry*; D057809:HEK293 Cells; D006801:Humans; D007368:Interferometry / Q000379:methods; D046228:Microarray Analysis / Q000295:instrumentation / Q000379:methods*