Superparamagnetic yolk–shell porous nanospheres of iron oxide@magnesium silicate: synthesis and application in high-performance anticancer drug delivery

Abstract

Superparamagnetic yolk–shell porous nanospheres of iron oxide@magnesium silicate (SPIO@MS) have been synthesized by a facile solvothermal approach based on a chemical-template etching mechanism using a mixed solution containing magnesium ions and acetate ions. The effects of the solvothermal time and the amount of MgCl₂·6H₂O as the magnesium source on the morphology of yolk–shell porous nanospheres of SPIO@MS are investigated, and the possible formation mechanism of yolk–shell porous nanospheres of SPIO@MS is proposed. The yolk–shell porous nanospheres of SPIO@MS prepared using 0.9 mmol MgCl₂·6H₂O at 180 °C for 24 h exhibit a high specific surface area (392.4 m² g⁻¹) and doxorubicin hydrochloride (DOX) loading amount (526 mg g⁻¹). More importantly, the SPIO@MS/DOX drug delivery system exhibits a sustained and pH-responsive drug release performance, and a much higher anticancer activity than free DOX in vitro. Therefore, the as-prepared yolk–shell porous nanospheres of SPIO@MS are promising for application in high-performance drug delivery.