Silica nanovehicles endow arsenic trioxide with an ability to effectively treat cancer cells and solid tumors

Arsenic trioxide is a clinical drug that can be used to successfully treat acute promyelocytic leukemia. However, its therapeutic effect on solid tumors is limited because of the poor pharmacokinetics and dose-limiting toxicity. Here, we report a facile strategy to achieve high anticancer activity of arsenic trioxide by loading the nanoparticulate prodrug into hollow silica inorganic nanoparticles. Because of the appropriate size, pH sensitivity, and surface targeted modification, this smart nanosized drug system can deliver arsenic trioxide into cancer cells efficiently and exhibits much higher cytotoxicity to a variety of cancer cells than free arsenic trioxide. Moreover, this nanomedicine can further promote the differentiation and inhibit the migration of cancer cells. In vivo results suggest that this drug delivery system can significantly inhibit the growth of solid tumors without adverse side effects. This study highlights a feasible drug delivery strategy to expand the use of arsenic trioxide for the effective treatment of solid tumors.