Using a lactadherin-immobilized silicon surface for capturing and monitoring plasma microvesicles as a foundation for diagnostic device development

Agnieszka Kamińska,Ewa Ł Stępień,Magdalena E Marzec,Anna Dłubacz,Olga Woźnicka,Katarzyna Gajos,Andrzej Budkowski

doi:10.1007/s00216-020-02938-5

Agnieszka Kamińska, Ewa Ł Stępień + Show 5 more

Open Access

https://doi.org/10.1007/s00216-020-02938-5

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Abstract

Microvesicles (MVs) are found in several types of body fluids and are promising disease biomarkers and therapeutic targets. This study aimed to develop a novel biofunctionalized surface for binding plasma microvesicles (PMVs) based on a lab-on-a-chip (LOC) approach. A new lactadherin (LACT)-functionalized surface was prepared and examined for monitoring PMVs. Moreover, two different strategies of LACT immobilization on a silicon surface were applied to compare different LACT orientations. A higher PMV to LACT binding efficiency was observed for LACT bonded to an αvβ3 integrin–functionalized surface compared with that for LACT directly bonded to a glutaraldehyde-modified surface. Effective binding of PMVs and its components for both LACT immobilization strategies was confirmed using spectral ellipsometry and time-of-flight secondary ion mass spectrometry methods. The proposed PMV capturing system can be used as a foundation to design novel point-of-care (POC) diagnostic devices to detect and characterize PMVs in clinical samples.Graphical

Highlights

Microvesicles (MVs), referred to as ectosomes, are a heterogenous population of extracellular vesicles ranging in diameter from about 100 nm to 1 μm, which arise by outward budding and shedding of the cell membrane [1]
The morphology and size distribution of isolated extracellular vesicles (EVs) including plasma microvesicles (PMVs) were determined by transmission electron microscopy (TEM) (Fig. 2a–c) and nanoparticle tracking analysis (NTA) (Fig. 2d), respectively
The NTA method showed that the isolated population of PMVs had a heterogenous size distribution with an average mean size of 134 ± 45 nm that is in line with the results obtained by Menck et al [22]

Summary

Introduction

Microvesicles (MVs), referred to as ectosomes, are a heterogenous population of extracellular vesicles ranging in diameter from about 100 nm to 1 μm, which arise by outward budding and shedding of the cell membrane [1]. During this process, cell membrane asymmetry is lost, accompanied by the exposure of phosphatidylserine (PS) on the outer membrane layer [2]. Use of plasma MVs (PMVs) has been proposed for anti-platelet therapy monitoring in clinical practice [6]. The main limitation in PMV analysis arises from the problem of obtaining a homogenous fraction of MVs, which is usually affected by different steps in the pre-analytical phase (sample collection, storage) and the diversity of isolation methods (centrifugation, filtration, etc.) [1, 9,10,11,12]

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