Merging Biological and Synthetic Nanoplatforms: Magnetic Engineering of Extracellular Vesicles via Liposome Fusion

Extracellular vesicles (EVs), liposomes, and magnetic nanoparticles (MNPs) are key nanoplatforms in biomedicine, motivating their integration into hybrid systems. Here, we engineer magnetic EV-liposome hybrids using fusogenic liposomes preloaded with MNPs and establish a multilevel framework to characterize their formation and function. Orthogonal single-particle analyses, including nanoparticle tracking, resistive pulse sensing, high-resolution flow cytometry, and electron microscopy, reveal rapid EV-liposome association into 100-200 nm Janus-like hybrids. Magnetic nanoparticles enable direct visualization of association dynamics by magnetophoresis at ensemble and single-particle levels. Protein assays and Western blotting confirm preservation of EV markers (CD63, CD81, Syntenin-1) and vesicle integrity. Functionally, magnetic guidance enhances hybrid uptake by cancer cells, combining biological tropism with external targeting. This strategy enables controlled engineering of magnetic EV hybrids with preserved identity and multifunctionality, and provides a methodological advance for monitoring nanoscale membrane fusion toward precision theranostics.