Isolating and analyzing tumor-derived exosomes (TEX) can provide important information about the state of a tumor, facilitating early diagnosis and prognosis. Since current isolation methods are mostly laborious and expensive, we propose herein a fast and cost-effective method based on a magnetic nanoplatform to isolate TEX. In this work, we have tested our method using three magnetic nanostructures: (i) Ni magnetic nanowires (MNWs) (1500 × 40 nm), (ii) Fe3 O4 nanorods (NRs) (41 × 7 nm), and (iii) Fe3 O4 cube-octahedral magnetosomes (MGs) (45 nm) obtained from magnetotactic bacteria. The magnetic response of these nanostructures has been characterized, and we have followed their internalization inside canine osteosarcoma OSCA-8 cells. An overall depiction has been obtained using a combination of Fluorescence and Scanning Electron Microscopies. In addition, Transmission Electron Microscopy images have shown that the nanostructures, with different signs of degradation, ended up being incorporated in endosomal compartments inside the cells. Small intra-endosomal vesicles that could be precursors for TEX have also been identified. Finally, TEX have been isolated using our magnetic isolation method and analyzed with a Nanoparticle tracking analyzer (NanoSight). We observed that the amount and purity of TEX isolated magnetically with MNWs was higher than with NRs and MGs, and they were close to the results obtained using conventional non-magnetic isolation methods.
Bibliographical noteFunding Information:
Funding: This research was supported by the MN Futures Program of the University of Minnesota, by the Skippy Frank Fund for Life Sciences and Translational Research, by Morris Animal Foundation Grant D15CA-047, and by the Animal Cancer Care and Research Program of the University of Minnesota. The Spanish Government is acknowledged for funding under the project number MAT2017-83631-C3. The Basque Government is acknowledged for funding under the project number IT1245-19. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure Network (NNCI) under Award Number ECCS-1542202.
- Cancer exosomes
- Magnetic isolation
University Imaging Centers