Synthesis and Characterization of SiO₂/nGO/Fe₃O₄/SeQDs Nanoparticles as Potential Nanocarriers in Drug Delivery...

Herein, we constructed the branch-shaped SiO₂/nano GO (nGO)/Fe₃O₄/selenium quantum dots (QDs) (SeQDs) nanoparticles (SGF/SeQDs) embodying magnetism, fluorescence, and microwave stimulus response properties to enhance the performance of releasing drugs. The SGF/SeQDs composite was characterized by technologies including powder X-ray diffraction, transmission electron microscopy, infrared spectroscopy, etc. In the nanoparticles, the branch-shaped SiO₂ provides a large specific surface area, nGO as the dielectric loss-style material promotes microwave-absorbing performance, and the Fe₃O₄ serves as a magnetic targeting agent and microwave absorber. Integrating nGO and Fe₃O₄ could further strengthen the microwave absorption of the entire composite; selenium features both fluorescence and anticancer effects. The synthesized nanoparticles as carriers exhibited a branch-like mesoporous sphere of ∼260 nm, a specific surface area of 258.57 m² g^-1, a saturation magnetization of 24.59 emu g^-1, and good microwave thermal conversion performance that the temperature was elevated from 25 to 70 °C under microwave irradiation. These physical characteristics, including large pore volume (5.30 nm), high specific surface area, and fibrous morphology, are in favor of loading drugs. Meanwhile, the cumulative etoposide (VP16) loading rate of the nanoparticles reached to 21 wt % after 360 min. The noncovalent interaction between the VP16 and SGF/SeQDs was mainly the hydrogen-bonding effect during the loading process. Furthermore, the drug release rates at 180 min were up to 81.46, 61.92, and 56.84 wt % at pH 4, 5, and 7, respectively. At 25, 37, and 50 °C, the rates of drug release reach 25.40, 56.84, and 65.32 wt %, respectively. After microwave stimulation at pH 7, the rate of releasing drug increased distinctly from 56.84 to 71.74 wt % compared to that of nonmicrowave irradiation. Cytotoxicity tests manifested that the carrier had good biocompatibility. Therefore, the nanoparticles are looking forward to paving one platform for further applications in biomedicine and drug delivery systems.