Light-activated nanoimpeller-controlled drug release in cancer cells

The use of nanoimpeller-controlled mesostructured silica nanoparticles to deliver and release anticancer drugs into living cells upon external command was investigated. Human cancer cells were exposed to suspensions of the particles and the particles were taken up by the cells. Confocal microscopy imaging of cells containing the particles loaded with the membrane-impermeable dye, propidium iodide (PI), showed that the PI is released from the particles only when the impellers are photoexcited, resulting in staining of the nuclei. The anticancer drug campothecin (CPT) was also loaded into and released from the particles inside the cells under light excitation, and apoptosis was induced. The LAMS particles functionalized with azobenzene molecules were synthesized using modifications of reported processes. Hydrophilic Rhodamine B was chosen as probe dye to verify that the moving parts are able to trap and release the probe molecules in an aqueous environment.