scholarly journals Abstract 1936: Label-free optical imaging and characterization of cancer-associated urinary extracellular vesicles: Implications for biomarker discovery

Author(s):  
Ronit Barkalifa ◽  
Sixian You ◽  
Haohua Tu ◽  
Alison Masyr ◽  
Rebecca Kamerer ◽  
...  
2018 ◽  
Vol 90 (19) ◽  
pp. 11290-11296 ◽  
Author(s):  
Wooje Lee ◽  
Afroditi Nanou ◽  
Linda Rikkert ◽  
Frank A. W. Coumans ◽  
Cees Otto ◽  
...  

2020 ◽  
Author(s):  
E. Priglinger ◽  
J. Strasser ◽  
B. Buchroithner ◽  
F. Weber ◽  
S. Wolbank ◽  
...  

AbstractInterest in mesenchymal stem cell derived extracellular vesicles (MSC-EVs) as therapeutic agents has dramatically increased over the last decade. Preclinical studies show that MSC-EVs have anti-apoptotic and neuroprotective effects, boost wound healing, and improve the integration of allogeneic grafts through immunomodulation. Current approaches to the characterization and quality control of EV-based therapeutics include particle tracking techniques, Western blotting, and advanced cytometry, but standardized methods are lacking. In this study, we established and verified quartz crystal microbalance (QCM) as highly sensitive label-free immunosensing technique for characterizing clinically approved umbilical cord MSC-EVs enriched by tangential flow filtration and ultracentrifugation. Using QCM in conjunction with common characterization methods, we were able to specifically detect EVs via EV (CD9, CD63, CD81) and MSC (CD44, CD49e, CD73) markers and gauge their prevalence. Additionally, we characterized the topography and elasticity of these EVs by atomic force microscopy (AFM), enabling us to distinguish between EVs and non-vesicular particles (NVPs) in a therapeutic formulation. This measurement modality makes it possible to identify EV sub-fractions, discriminate between EVs and NVPs, and to characterize EV surface proteins, all with minimal sample preparation and using label-free measurement devices with low barriers of entry for labs looking to widen their spectrum of characterization techniques. Our combination of QCM with impedance measurement (QCM-I) and AFM measurements provides a robust multi-marker approach to the characterization of clinically approved EV formulations and opens the door to improved quality control.


2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Monika Dzieciatkowska ◽  
Guihong Qi ◽  
Jinsam You ◽  
Kerry G. Bemis ◽  
Heather Sahm ◽  
...  

Cerebrospinal fluid (CSF) has been used for biomarker discovery of neurodegenerative diseases in humans since biological changes in the brain can be seen in this biofluid. Inactivation of A-T-mutated protein (ATM), a multifunctional protein kinase, is responsible for A-T, yet biochemical studies have not succeeded in conclusively identifying the molecular mechanism(s) underlying the neurodegeneration seen in A-T patients or the proteins that can be used as biomarkers for neurologic assessment of A-T or as potential therapeutic targets. In this study, we applied a high-throughput LC/MS-based label-free protein quantification technology to quantitatively characterize the proteins in CSF samples in order to identify differentially expressed proteins that can serve as potential biomarker candidates for A-T. Among 204 identified CSF proteins with high peptide-identification confidence, thirteen showed significant protein expression changes. Bioinformatic analysis revealed that these 13 proteins are either involved in neurodegenerative disorders or cancer. Future molecular and functional characterization of these proteins would provide more insights into the potential therapeutic targets for the treatment of A-T and the biomarkers that can be used to monitor or predict A-T disease progression. Clinical validation studies are required before any of these proteins can be developed into clinically useful biomarkers.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2634
Author(s):  
Elisa Chiodi ◽  
George G. Daaboul ◽  
Allison M. Marn ◽  
M. Selim Ünlü

Extracellular vesicles (EVs) have attracted significant attention as impactful diagnostic biomarkers, since their properties are closely related to specific clinical conditions. However, designing experiments that involve EVs phenotyping is usually highly challenging and time-consuming, due to laborious optimization steps that require very long or even overnight incubation durations. In this work, we demonstrate label-free, real-time detection, and phenotyping of extracellular vesicles binding to a multiplexed surface. With the ability for label-free kinetic binding measurements using the Interferometric Reflectance Imaging Sensor (IRIS) in a microfluidic chamber, we successfully optimize the capture reaction by tuning various assay conditions (incubation time, flow conditions, surface probe density, and specificity). A single (less than 1 h) experiment allows for characterization of binding affinities of the EVs to multiplexed probes. We demonstrate kinetic characterization of 18 different probe conditions, namely three different antibodies, each spotted at six different concentrations, simultaneously. The affinity characterization is then analyzed through a model that considers the complexity of multivalent binding of large structures to a carpet of probes and therefore introduces a combination of fast and slow association and dissociation parameters. Additionally, our results confirm higher affinity of EVs to aCD81 with respect to aCD9 and aCD63. Single-vesicle imaging measurements corroborate our findings, as well as confirming the EVs nature of the captured particles through fluorescence staining of the EVs membrane and cargo.


2021 ◽  
Vol 2086 (1) ◽  
pp. 012107
Author(s):  
A V Aybush ◽  
A A Gulin ◽  
A A Kuzoiatova ◽  
M V Gubina ◽  
F E Gostev ◽  
...  

Abstract Paracrine functions of mesenchymal stem (stromal) cells (MSCs) rely, at least partly, on membrane-bound extracellular vesicles (EVs) with rich composition of lipids, nucleic acids and signaling proteins. Elucidation the underlying chemistry could potentially lead to MSCs-free therapy. However, the secretome of MSCs (EVs’ composition) is non-static and depends on many other factors including surrounding cells and medium. Thus, the research techniques must be able to provide not only bulk but microscopy-scale data within a reasonable time frame. Two of these label-free techniques are subject of this work toward the question of chemical composition of the EVs.


2017 ◽  
Vol 13 (12) ◽  
pp. 731-749 ◽  
Author(s):  
Michael L. Merchant ◽  
Ilse M. Rood ◽  
Jeroen K. J. Deegens ◽  
Jon B. Klein

2021 ◽  
Author(s):  
Elisa Chiodi ◽  
George G. Daaboul ◽  
Allison Marn ◽  
M. Selim Ünlü

<p>Extracellular vesicles (EVs) have attracted significant attention as impactful diagnostic biomarkers, since their properties are closely related to specific clinical conditions. However, designing experiments that involve EVs phenotyping is usually highly challenging and time-consuming, due to laborious optimization steps that require very long or even overnight incubation durations. In this work, we demonstrate label-free, real-time detection and phenotyping of extracellular vesicles binding to a multiplexed surface. With the ability of label-free kinetic binding measurements using the Interferometric Reflectance Imaging Sensor (IRIS) in a microfluidic chamber, we successfully optimize the capture reaction by tuning various assay conditions (incubation time, flow conditions, surface probe density and specificity). A single (less than 1 hour) experiment allows for characterization of binding affinities of the EVs to multiplexed probes. We demonstrate kinetic characterization of 18 different probe conditions, namely three different antobodies, each spotted at six different concentrations, simultaneously. The affinity characterization is then analyzed through a model which considers the complexity of multivalent binding of large structures to a carpet of probes, and therefore introduces a combination of fast and slow association and dissociation parameters. Additionally, our results confirm higher affinity of EVs to aCD81 with respect to aCD9 and aCD63. Single-vesicle imaging measurements corroborate our findings, as well as confirming the EVs nature of the captured particles through fluorescence staining of the EVs membrane and cargo. </p>


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