Magnetic nanoparticles loaded with functional RNA nanoparticles.

RNA is now widely acknowledged not only as a multifunctional biopolymer but also as a dynamic material for constructing nanostructures with various biological functions. Programmable RNA nanoparticles (NPs) allow precise control over their formulation and activation of multiple functionalities, with the potential to self-assemble in biological systems. These attributes make them attractive for drug delivery and therapeutic applications. In the present study, we demonstrate the ability of iron oxide magnetic nanoparticles (MNPs) to deliver different types of RNA NPs functionalized with dicer substrate RNAs inside human cells. Our results show that use of functionalized RNA NPs result in statistically higher transfection efficiency compared to the use of RNA duplexes. Furthermore, we show that the nucleic acids in the MNP/RNA NP complexes are protected from nuclease degradation and that they can achieve knockdown of target protein expression, which is amplified by magnetic stimulus. The current work represents the very first report indicating that iron oxide nanoparticles may efficiently protect and deliver programmable RNA NPs to human cells.