Synthesis of multifunctional hollow SiO2-CaO-Fe2O3 glass-ceramic nanospheres

Glass ceramics with multifunctions of bioactivity, drug delivery, and magnetic hyperthermia have great potential applications in the field of bioscience. Herein, we design and synthesize a multifunctional hollow SiO2-CaO-Fe2O3 (SCF) glass-ceramic nanosphere (GCNS) by a template-mediated sol-gel precipitate method. The magnetite as the main crystal phase was successfully precipitated from the SCF glassy matrixes after heat treated at 800 degrees C. The influence of composition and the Fe3+/Fe2+ precursor ratio on the morphology, crystallization, micropore structure, and magnetic properties were systematically studied. Intact spherical hollow SCF GCNSs were obtained under the heat treatment at 800 degrees C for 2 hours when the Fe2O3 content below 15 wt%. Under certain Fe2O3 content, the coercivity and micropore volume of SCF GCNSs were found to be increased with increasing the mole ratio of FeCl3/FeCl2 precursors. High drug loading capacity of 24.2 wt% and sustained drug release were observed from the methylene blue-loaded SCF GCNSs in simulated body fluid solution. The hollow SCF GCNSs synthesized in this work exhibiting good magnetic properties and sustained drug release performance have great potential applications in the cancer therapy.