Highly Selective Purification of Plasma Extracellular Vesicles Using Titanium Dioxide Microparticles for Depicting the Metabolic Signatures of Diabetic Retinopathy

Abstract

Extracellular vesicle (EV) cargos with regular fluctuations hold the potential for providing chemical predictors toward clinical diagnosis and prognosis. A plasma sample is one of the most important sources of circulating EVs, yet the technical barrier and cost consumption in plasma-EV isolation still limit its application in disease diagnosis and biomarker discovery. Here, we introduced an easy-to-use strategy that allows selectively purifying small EVs (sEVs) from human plasma and detecting their metabolic alternations. Fe 3 O 4 @TiO 2 microbeads with a rough island-shaped surface have proven the capability of performing efficient and reversible sEV capture owing to the phospholipid affinity, enhanced binding sites, and size-exclusion-like effect of the rough TiO 2 shell. The proposed system can also shorten the separation procedure from hours to 20 min when compared with the ultracentrifugation method and yield approximately 10 8 sEV particles from 100 μL of plasma. Metabolome variations of sEVs among progressive diabetic retinopathy subjects were finally studied, observing a cluster of metabolites with elevated levels and suggesting potential roles of these sEV chemicals in diabetic retinopathy onset and progression. Such a scalable and flexible EV capture system can be seen as an effective analytical tool for facilitating plasma-based liquid biopsies.

Recent advances of liquid biopsy: Interdisciplinary strategies toward clinical decision‐making

“…Non-specific isolation: (D) TiO 2 -lipid affinity Reproduced with permission. 153 Copyright 2022, American Chemical Society. (E) DSPE inserting.…”

“…Hu et al employed this user-friendly strategy selectively isolating EVs and detecting their metabolic alternations (Figure 6D). 153 Zhang and co-workers reported a similar TiO 2 -mediated EV isolation strategy from a small volume of plasma, where they simultaneously profiled proteins and metabolites. 161 Another research group utilized this strategy for reversible EV isolation, achieving high recovery rates (93.4%) using an alkaline solution.…”

Metabolomics of Extracellular Vesicles: A Future Promise of Multiple Clinical Applications

“… 71 Recently, an effective EV capture system using Titanium Dioxide microparticles has been designed to facilitate plasma-based liquid biopsies to understand the metabolic signatures of diabetic retinopathy. 72 …”

“…71 Recently, an effective EV capture system using Titanium Dioxide microparticles has been designed to facilitate plasma-based liquid biopsies to understand the metabolic signatures of diabetic retinopathy. 72 Figure 3 Application of EV metabolomics. The analysis of EVs metabolomics usually requires for several steps, including isolation of EVs, mass spectrometry analysis of inner metabolites and analysis of the metabolic maps.…”

Employing the Anchor DSPE-PEG as a Redox Probe for Ratiometric Electrochemical Detection of Surface Proteins on Extracellular Vesicles with Aptamers

“…Proteins on EVs exhibit distinct functions compared with proteins in vesicle-free states. Previous works have demonstrated that the diagnostic value of proteins involved in EVs is different from the corresponding proteins presented in plasma in vesicle-free states. , Recently, some groups have used membrane affinity molecules to isolate EVs based on their high affinity toward the phospholipid bilayer of EVs, − which is applicable to capture all EVs regardless of size and protein composition. For instance, Fang’ s group employed distearoyl phosphoethanolamine (DSPE)-modified magnetic beads to capture EVs and simultaneously detected the membrane protein and RNA with aptamer-assisted PCR .…”