Silica-based complex nanorattles as multifunctional carrier for anticancer drug

In this work, we demonstrate a new route to generate silica-based multifunctional complex nanorattles. By using SnO₂ hollow nanospheres as the starting template, we are able to build a new type of rattle-in-ball hollow structure with multi-level interior architecture, where the core of a nanorattle is itself another smaller rattle. Moreover, additional functionality can be introduced by forming Au nanoparticles in the interstitial space. Such unique hollow nanostructures are believed to be very useful as nanoreactors for selective catalysis. Magnetic functionality can also be incorporated by using an α-Fe₂O₃ nanospindle as the starting template followed by in situ reduction to Fe₃O₄. This type of ellipsoidal nanorattle is feasible for drug delivery as it is shown to be highly biocompatible and non-cytotoxic. The cell viability assay proves that the sample is an efficient drug delivery vehicle exhibiting similar anticancer efficacy against MCF-7 carcinoma cells as compared to the free DOX. By constructing these two types of complex nanorattles as examples, we demonstrate new possible routes to generate versatile hollow nanostructures with distinct architectures and chemical compositions, thus widening their application potential. © 2011 The Royal Society of Chemistry.