Molecular screening of cancer-derived exosomes by surface plasmon resonance spectroscopy

Abstract

We report on a generic method to detect and identify the molecular profile of exosomes either derived from cultured cell lines or isolated from biofluids. Exosomes are nanovesicles shed by cells into their microenvironment and carry the molecular identity of their mother cells. These vesicles are actively involved in intercellular communication under physiological conditions and ultimately in the spread of various diseases such as cancer. As they are accessible in most biofluids (e.g., blood, urine, or saliva), these biological entities are promising tools for cancer diagnostics, offering a non-invasive and remote access to the molecular state of the disease. The composition of exosomes derived from cancer cells depends on the sort and state of the tumor, requiring a screening of multiple antigens to fully characterize the disease. Here, we exploited the capacity of surface plasmon resonance biosensing to detect simultaneously multiple exosomal and cancer biomarkers on exosomes derived from breast cancer cells. We developed an immunosensor surface which provides efficient and specific capture of exosomes, together with their identification through their distinct molecular profiles. The successful analysis of blood samples demonstrated the suitability of our bioanalytical procedure for clinical use.Electronic supplementary materialThe online version of this article (doi:10.1007/s00216-015-8711-5) contains supplementary material, which is available to authorized users.

Targeting Tumor‐Associated Exosomes with Integrin‐Binding Peptides

“…While SPR has been recently applied to EV characterization, these reports were performed using surface-immobilized antibodies targeted against surface proteins of vesicles, for instance anti-CD9 or anti-CD63. [40] Since most types of EVs express such generic membrane proteins in their membrane surfaces, they are unable to distinguish between tumor and healthy EVs. Instead, in this proof-of-concept model system, we demonstrate that immobilized LXY30 peptide on an SPR chip surface could capture the tumor EVs, and furthermore, that the surface-associated biolayer of captured EVs can be characterized for average thickness (d) and refractive index (n).…”

Immobilization and detection of platelet-derived extracellular vesicles on functionalized silicon substrate: cytometric and spectrometric approach

“…1g). Such diversity of EV antigens is commonly observed in biological samples and may be useful for EV profiling [10, 15]. …”

“…The use of electrochemical potential-modulated electrochemical impedance spectroscopy (EIS) [12] and other methods that utilize the Coulter principle to determine the absolute size distribution of vesicles in suspension, such as resistive pulse sensing (RPS) [13, 14] and surface plasmon resonance spectroscopy [15], have recently been proposed. Another innovative label-free optical method is grating coupled interferometry (GCI).…”

Bulk immunoassays for analysis of extracellular vesicles

“…The time data allow the study of kinetics of interaction between EV and the surface. Because the refractive index contrast between buffer and EV is sufficiently large, no reporter is needed for readout [15][16][17][18], which is why SPR is sometimes referred to as a label-free technique. The change in refractive index provides information on the amount of captured material [19].…”