Hierarchical magnetic nanoparticles for highly effective capture of small extracellular vesicles

Small extracellular vesicles (EVs) have various functions through the transfer of specific biomolecules. However, it is still challenging to capture small EVs with high sensitivity and specificity. Herein, inspired by the unique burry structure and the strong adhesion ability of pollen grains, we presented a novel Fe₃O₄@MgSiO₃ hierarchical magnetic nanoparticles (HNPs) as nanocarriers for the capture of small EVs. The NPs were generated through the solvothermal method and further modified with branching dendrimers to exhibit a hierarchical morphology. The enlarged surface area facilitated high-efficient capture of small EVs through specific recognition of aptamer probes and the small EVs surface markers. Besides, the magnetic core of the NPs allowed them to be isolated under the action of an external magnetic field, and thus the captured small EVs could be easily separated from plasma. These results indicated that the HNPs could serve as excellent nanocarriers for small EVs capture and related biomedical applications.