Graphene Oxide Covalently Grafted Fe₂B@SiO₂ Nanoparticles for Epirubicin Loading and Releasing

In this work, stable superparamagnetic core shell Fe2B@SiO2 nanoparticles were prepared by "one pot" chemical reduction of ferric ion salts with NaBH4 and silica shell coating in the presence of citric acid stabilizer. The X-ray (XRD) and selection of electron diffraction (SAED) revealed that Fe2B@SiO2 nanoparticles were chiefly composed of silica shell and Fe2B with a small amount of alpha-Fe. Then, graphene oxide (GO) was assembled onto core-shell Fe2B@SiO2 nanoparticles for Epirubicin (EPI) loading and releasing, and the adsorption isotherm of EPI on Fe2B@SiO2@GO was analyzed. The results showed, the adsorption process includes two steps, due to the pi-pi stacking effect of EPI on the Fe2B@SiO2@GO. The EPI loading efficiency of the magnetic nanoparticles was as high as 90%, while the EPI-loaded core-shell Fe2B@SiO2 nanoparticles showed an obvious pH controlled drug release behavior, and showed lower cumulative release rate when pH is 7.4 than that when pH is 5.7. The prepared nanoparticles demonstrated potential application in killing tumor cells while minimizing the toxicity to normal tissues.