Enhanced Delivery of Therapeutic siRNA into Glioblastoma Cells Using Dendrimer-Entrapped Gold Nanoparticles Conjugated with β-Cyclodextrin

We describe a safe and highly effective non-viral vector system based on β-cyclodextrin (β-CD)-modified dendrimer-entrapped gold nanoparticles (Au DENPs) for improved delivery small interfering RNA (siRNA) to glioblastoma cells. In our approach, we utilized amine-terminated generation 5 poly(amidoamine) dendrimers partially grafted with β-CD as a nanoreactor to entrap Au NPs. The acquired β-CD-modified Au DENPs (Au DENPs-β-CD) were complexed with two different types of therapeutic siRNA (B-cell lymphoma/leukemia-2 (Bcl-2) siRNA and vascular endothelial growth factor (VEGF) siRNA). The siRNA compression ability of the Au DENPs-β-CD was evaluated by various methods. The cytocompatibility of the vector/siRNA polyplexes was assessed by viability assay of cells. The siRNA transfection capability of the formed Au DENPs-β-CD vector was evaluated by flow cytometric assay of the cellular uptake of the polyplexes and Western blot assays of the Bcl-2 and VEGF protein expression. Our data reveals that the formed Au DENPs-β-CD carrier enables efficiently delivery of siRNA to glioma cells, has good cytocompatibility once complexed with the siRNA, and enables enhanced gene silencing to inhibit the expression of Bcl-2 and VEGF proteins. The developed Au DENPs-β-CD vector may be used for efficient siRNA delivery to different biosystems for therapeutic purposes.