Synthesis of multifunctional superparamagnetic mesoporous ZnMnFe2O4@Fe-CaSiO3 core-shell for medical applications

Herein, we report the synthesis of a mesoporous calcium silicate superparamagnetic nanoparticle as ZnMnFe2O4@Fe-CaSiO3 core-shell. This core-shell nanocomposite reveals excellent properties such as meso-porous nanocomposite, superparamagnetic at room temperature, low toxicity, large surface area, tunable pore size, and easy surface manipulation. The core nanocomposite (ZnMnFe2O4) is synthesized by the hydrothermal method, which shows a superparamagnetic behavior with an excellent saturation magnetization of 52.09 emu/g. The core-shell structure is prepared by a micellar-assisted sol-gel method, which uses a copolymer to create pores in the structure of CaSiO3. To improve the magnetic properties of the core-shell structure, different percent of Fe ions (0%, 5%, and 10%) are doped onto the calcium silicate structure; as for 10% Fe, i.e., ZnMnFe2O4@-Fe10-CaSiO3, saturation magnetization and coercive magnetic field are 34.543 emu/g and 1Oe, respectively. In this configuration of nanocomposite, the pore volume and superparamagnetic property increase simultaneously. In addition, the core-shell mesoporous ZnMnFe2O4@Fe-CaSiO3 nanocomposite reveals comparable mesoporous channels (3.4-6 nm), while the amorphous structure of CaSiO3 has not been changed. These core-shell meso-porous superparamagnetic nanocomposites are evaluated in terms of drug loading and release using epirubicin (EPI) as a model drug. It is found that the increase of iron ions improves the capacity to stabilize the pH envi-ronment. Additionally, the mesoporous Fe-CaSiO3 nanostructures demonstrate a sustained drug release property that could be used in local drug delivery therapy. Therefore, these mesoporous superparamagnetic nano-structures would be a promising multifunctional platform for local drug delivery, magnetic resonance imaging, magnetic hyperthermia, and bone tissue regeneration.

Automated summary

We report the synthesis of a mesoporous calcium silicate superparamagnetic nanoparticle with a core-shell structure of ZnMnFe2O4@Fe-CaSiO3. The core-shell nanocomposite exhibits excellent properties including meso-porous structure, superparamagnetism at room temperature, low toxicity, large surface area, tunable pore size, and easy surface manipulation. The addition of different percentages of Fe ions onto the calcium silicate structure further enhances the magnetic properties of the core-shell structure. These mesoporous superparamagnetic nanocomposites have potential applications in drug delivery, magnetic resonance imaging, magnetic hyperthermia, and bone tissue regeneration.