Synthesis of nanostructured calcium carbonate/methotrexate@silica and its application in cancer therapy

Biomedical applications of nontoxic amorphous calcium carbonate (ACC) have mainly been restricted because of its aqueous instability. Herein, we report the successful synthesis of highly stable ACC-methotrexate (MTX)@SiO2 nanospheres in vitro for use in cancer therapy. Further, vaterite-MTX@SiO2 nanospheres were also prepared for comparison. In our synthesis procedure, ACC-MTX and vaterite-MTX were firstly prepared at different pH values, and then SiO2 layers were subsequently deposited by the well-known Stober method. The results indicated that the special structure of ACC-MTX@SiO2 presents better controlled-release and results in efficient death of cancer cells, thus showing its great potential as a desirable chemotherapeutic system for cancer therapy.