Facile Synthesis of Bifunctional Metal–Organic Framework Nanoparticles for Isolation of Extracellular Vesicles

Abstract

Extracellular vesicles (EVs) play a vital role in mediating cell communication by transferring their contained constituents. The field of EV studies continues to attract popular interests due to the pathophysiological function and clinical application values of EVs. Various kinds of materials have been developed to isolate EVs from complex biological samples. In this work, we develop a two-step "green" strategy to prepare a distearoyl phospholipid ethanolamine (DSPE) functionalized UiO-66 metal−organic framework (MOF) nanomaterial with water as the solvent at room temperature (RT). This synthesized process was facile, simple, safe, economical, environmentally friendly, and sustainable. The obtained UiO-66-DSPE material could be applied to efficiently enrich EVs from a cell medium and urinary samples by taking advantages of the affinity interaction of Zr 4+ and the synergistic effect of DSPE insertion toward the phospholipid membrane of EVs. More than 99% of captured EVs could be released by alkaline elution, and the eluted EVs could maintain their structural integrity and biological activity. Furthermore, 112 upregulated proteins and 45 downregulated proteins were identified by comparing the urinary EVs of colorectal cancer (CRC) patients with those of healthy donors, and some of them were closely related to the CRC progression. These results indicated that the EV isolation method based on the bifunctional UiO-66-DSPE nanoparticles might provide a potential approach in the further analysis of EVs for cancer diagnosis.

Recent research on material-based methods for isolation of extracellular vesicles

“…70 In addition to the above-mentioned single-function capture strategy, isolation methods with the bifunctional principle have also been gradually developed and applied. 71 Sun et al demonstrated that after functionalized modification of DSPE-PEG lipid probes on the surface of titanium functional magnetic beads, the synergistic effect of the probe and titanium ions can achieve efficient capture of EVs. 72 In addition to DSPE probes, cholesterol can also be used to capture EVs.…”

“…The obtained UiO-66-DSPE material could be applied to efficiently enrich EVs from cell medium and urinary samples, and more than 99% of captured EVs could be released by alkaline elution, which could maintain their structural integrity and biological activity. 71 Compared with antibody, aptamer or phospholipid based methods, the cost of these materials (MOF and TiO 2 ) were relatively low, and they showed excellent isolation performance. Therefore, material-based methods exhibit significant potential for early diagnosis and disease surveillance.…”

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

“…In 2017, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE) emerged as a promising probe for non-specific EV isolation, since it can insert into the phospholipid membrane of EVs through its two hydrophobic fatty acid tails. 44 Wang et al prepared DSPEfunctionalized UiO-66 metal-organic framework, 154 by leveraging the synergistic affinity interaction of Zr 4þ ion and DSPE with EVs for efficiently EV enrichment from urinary samples, achieving release efficiency up to 99% through alkaline elution (Figure 6E). Chen et al intravenously injected DSPE-PEG-Biotin to directly label circulating EVs in vivo, aiming to minimize alterations in their behavior.…”

“…Wang et al. prepared DSPE‐functionalized UiO‐66 metal‐organic framework, 154 by leveraging the synergistic affinity interaction of Zr 4+ ion and DSPE with EVs for efficiently EV enrichment from urinary samples, achieving release efficiency up to 99% through alkaline elution (Figure 6E). Chen et al.…”

Buoyant Metal–Organic Framework Corona-Driven Fast Isolation and Ultrasensitive Profiling of Circulating Extracellular Vesicles

“…Currently, many isolation methods (e.g., ultracentrifugation, coprecipitation, and size exclusion), and detection techniques, such as optical, electrical, and acoustic sensors, − have been broadly deployed in EV assays, whereas they stress on either EV enrichment or quantification. , Although bioaffinity magnetic particles and microfluidics have advanced EV isolation and detection, − they usually require costly antibodies (e.g., antibody cocktail) and are heavily relied on microfabrication or external forces, , thus limiting the usage of EVs in clinical settings in a more competent fashion. In comparison, transition-metal elements show cost-effective coordinative affinity toward EVs. − Based on such affinities, Ti-based metal oxides (TiO 2 ) and Zr-based metal–organic frameworks (Zr-MOFs) have been exploited for EV capture, − whereas the unordered accumulation or overdispersion of these particles largely degrades downstream in situ, on-site, and multiplexed EV analysis. Despite the progress, developing clinically feasible EV tests, however, is still hampered by several technical challenges, including (i) multistep manual sample separation, (ii) low enrichment efficiency, (iii) limited sensitivity and readout, (iv) costly multiple antibody pairs, and (v) over-reliance on external force or microfabrication.…”