Extracellular vesicles (EVs), particularly exosomes, are emerging biomarker sources. However, due to heterogeneous populations secreted from diverse cell types, mapping EV multi-omic molecular information specifically to their pathogenesis origin for cancer biomarker identification is still extraordinary challenging. University of Kansas researchers introduced a novel 3D-structured nanographene immunomagnetic particles (NanoPoms) with unique flower pom-poms morphology and photo-click chemistry for specific marker-defined capture and release of intact small EVs. This specific EV isolation approach leads to the expanded identification of targetable cancer biomarkers with enhanced specificity and sensitivity, as demonstrated by multi-omic EV analysis of bladder cancer patient tissue fluids using the next generation sequencing of somatic DNA mutations, miRNAs, and the global proteome. The NanoPoms prepared sEVs also exhibit distinctive in vivo biodistribution patterns, highlighting the highly viable and integral quality. The developed method is simple and straightforward, and is applicable to nearly all types of biological fluids and amenable for scale up and high-throughput EV isolation.
Nano pom-poms fabrication for highly specific sEVs
isolation and multi-omic biomarker analysis
(A) Schematic illustration of the fabrication of Nano pom poms. (B) TEM and SEM images showing the unique 3D nano-scale flower pom-poms morphology compared to commercial immunomagnetic beads. (C) TEM imaging of captured sEVs fully covering Nano pom-poms surface. The captured EVs are confirmed by antiCD63 gold nanoparticle immune TEM imaging. The insert shows the captured single EV in the size range of ~100 nm with three gold nanoparticles bound (~10 nm). (D) Nanoparticle tracking analysis of NanoPoms isolated sEVs with much narrower size distribution in comparison with UC isolated EVs. (E) SEM images showing the dense sEVs are captured on Nano pom-poms, and can be completely released via on-demand photo-cleavage. After release, intact sEVs can be harvested for downstream multi-omic analysis including next generation sequencing of DNAs, RNAs, western blotting and proteomic analysis, as well as the in vivo study.