Fe₃O₄@SiO₂-Protein A-oHSV/CD63 Ab for Capturing Virus and Exosomes

Protein A modified magnetic spheres (Fe₃O₄@SiO₂-Protein A) with 22.7 emu/g saturation magnetization were prepared and characterized. These spheres had a diameter of 10 nm and was stable up to 229.2 °C, and can bond 19.694 mg/g of Protein A. The Fe₃O₄@SiO₂-Protein A was firstly combined with oHSV-BJ-2-A antibody to capture oHSV from disease venom, and the amount of binding virus was 1.92 × 10⁷ to 3.44 × 10⁷ PFU/g. Fe₃O₄@SiO₂-Protein A was modified with CD63 antibody, which was further fixed using dissuccinimide octylate (DSS) as a crosslinking agent. The prepared Fe₃O₄@SiO₂-Protein A-CD63 Ab was useful in isolating and enriching exosomes from cell supernatant. Compared with commercial kits, Fe₃O₄@SiO₂-Protein A-CD63 Ab demonstrated a better purification effect, which was successfully monitored using capillary electrophoresis. The total content of exosomes protein extracted using Fe₃O₄@SiO₂-Protein A-CD63 was 3.4 mg/g, which was obviously higher than that reported in some studies. In addition, Fe₃O₄@SiO₂-Protein A-CD63 Ab also showed its repeatability through bonding and elution of 5 cycles, which was effective in cost saving. These indicated Fe₃O₄@SiO₂-Protein A-CD63 Ab had the potential for large-scale purification of exosomes in practical applications.