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

Jieru Qiu,Xiangyang Shi,Lingdan Kong,Lu Wang,Aijun Li,Serge Mignani,Xueyan Cao,Anne-Marie Caminade,Jean-Pierre Majoral,Ping Wei

doi:10.3390/nano8030131

Abstract

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.

Highlights

Gene therapy is becoming a promising strategy for cancer therapy by transfecting genetic materials into target cancer cells to achieve the therapeutic purposes
We have shown that the Au NP entrapment within generation 5 (G5) PAMAM dendrimers to form dendrimer-entrapped Au NPs (Au DENPs) is beneficial to reduce the cytotoxicity of dendrimers and simultaneously enhance the gene delivery efficiency [44]
The prepared Au DENPs-β-CD were employed as a vector to compact two different types of Small interfering RNA (siRNA) including B-cell lymphoma 2 (Bcl-2) siRNA and vascular endothelial growth factor (VEGF) siRNA under the appropriate N/P ratios for oncogene silencing (Scheme 1)

Summary

Introduction

Gene therapy is becoming a promising strategy for cancer therapy by transfecting genetic materials (such as DNA [1,2,3], RNA [4,5] and antisense oligonucleotides [6,7]) into target cancer cells to achieve the therapeutic purposes. Several studies have reported that by functional modifications of generation 5 (G5) PAMAM dendrimers via dendrimer periphery modification of polyethylene glycol chains [43] or entrapment of gold (Au) NPs within dendrimer internal cavities [44], the cytotoxicity of the vector has been significantly reduced, while the gene transfection efficiency has been prominently enhanced [14,44,45,46,47]. We have shown that the Au NP entrapment within G5 PAMAM dendrimers to form dendrimer-entrapped Au NPs (Au DENPs) is beneficial to reduce the cytotoxicity of dendrimers and simultaneously enhance the gene delivery efficiency [44].

Results

Conclusion