# Immunoconjugated Magnetic Graphene for Exosome Capture in SARS-CoV-2 Pseudovirus-Infected Cells

## TL;DR

Researchers developed a new graphene-based method to isolate exosomes from cells infected with a SARS-CoV-2 pseudovirus, which could help study virus-host interactions and improve diagnostics.

## Contribution

The study introduces MAGU-anti-CD9, a novel magnetic graphene-based tool for selective exosome isolation in viral research.

## Key findings

- MAGU-anti-CD9 efficiently isolated CD9+ exosomes with canonical markers like ALIX, CD147, TSG101, and Flotillin-1.
- Exosomes from SARS-CoV-2 pseudovirus-infected cells showed enrichment in CD147, a potential cofactor in viral entry.
- The method supports molecular profiling of exosome subpopulations for virus-host interaction studies and diagnostics.

## Abstract

Graphene-based nanomaterials exhibit exceptional physicochemical properties that facilitate a range of diverse biomedical applications, including liquid biopsy. In this study, graphene-based magnetic units, termed MAGU (MAGnetic Units), were specifically engineered for the selective isolation of exosomes. Total extracellular vesicles were first enriched using ultracentrifugation, followed by immunomagnetic capture of CD9+ exosomes. MAGU functionalized with anti-CD9 antibody (MAGU-anti-CD9) efficiently recovered a CD9-positive exosome subpopulation expressing canonical markers ALIX, CD147, TSG101, and Flotillin-1, thereby confirming selective isolation performance. To investigate viral associated signaling, 293T cells were transduced with SARS-CoV-2 spike pseudovirus. This pseudovirus was engineered to express the SARS-CoV-2 spike protein, enabling simulation of viral entry and assessment of potential alterations in the exosomal profile induced by viral binding. Exosomes released by pseudovirus-transduced 293T cells were analyzed and compared to those from non-transduced controls. The MAGU-anti-CD9 complex selectively isolated a defined subset of CD9-positive vesicles enriched in the multifunctional transmembrane glycoprotein CD147, which has been proposed as a cofactor in SARS-CoV-2 entry. Comprehensive molecular profiling of selectively captured exosome subpopulations is expected to further support the application of MAGU technology in virus–host interaction research and liquid-biopsy-based diagnostics.