Gene regulation by intracellular delivery and photodegradation of nanoparticles containing small interfering RNA.

Although the use of small interfering RNA (siRNA) is a promising technique for gene regulation, spatiotemporal control of the effects of siRNA must be achieved if the technique is to be safe and practical. Here, a method for spatiotemporal regulation of genes with nanoparticles containing siRNA is reported. The siRNA is encapsulated in photodegradable nanoparticles that are internalized to SKOV3-Luc cells, where the siRNA is released from the nanoparticles by UV irradiation for 30 s. The encapsulated siRNA only shows no gene-silencing effects, but release of the siRNA upon UV radiation leads to sequence-specific silencing of the luciferase gene in the cells. These results indicate that photodegradable siRNA-containing nanoparticles can be useful for time- and space-dependent regulation of gene expression in cells.