Interaction of Cationic Carbosilane Dendrimers and Their siRNA Complexes with MCF-7 Cells.

Kamila Białkowska,Tania Lozano-Cruz,Rafael Gomez-Ramirez,Maria Bryszewska,Sylwia Michlewska,Piotr Komorowski,Paulina Sokołowska,Francisco Javier De La Mata,Katarzyna Miłowska

doi:10.3390/ijms22137097

Abstract

The application of siRNA in gene therapy is mainly limited because of the problems with its transport into cells. Utilization of cationic dendrimers as siRNA carriers seems to be a promising solution in overcoming these issues, due to their positive charge and ability to penetrate cell membranes. The following two types of carbosilane dendrimers were examined: CBD-1 and CBD-2. Dendrimers were complexed with pro-apoptotic siRNA (Mcl-1 and Bcl-2) and the complexes were characterized by measuring their zeta potential, circular dichroism and fluorescence of ethidium bromide associated with dendrimers. CBD-2/siRNA complexes were also examined by agarose gel electrophoresis. Both dendrimers form complexes with siRNA. Moreover, the cellular uptake and influence on the cell viability of the dendrimers and dendriplexes were evaluated using microscopic methods and XTT assay on MCF-7 cells. Microscopy showed that both dendrimers can transport siRNA into cells; however, a cytotoxicity assay showed differences in the toxicity of these dendrimers.

Highlights

One of the most common causes of death in the world is cancer
Measurements of the physical properties of dendriplexes, electrophoresis and ethidium bromide assay have confirmed that both tested dendrimers complex with small interfering RNAs (siRNAs)
Confocal microscopy indicates that both dendrimers can effectively deliver siRNA into target cells

Summary

Introduction

One of the most common causes of death in the world is cancer. Finding new methods of treatment is a big challenge because of heterogeneity and metastasis [1,2]. The main regulators of apoptosis are proteins belonging to the Bcl-2 family, consisting of pro- and anti-apoptotic proteins [3]. One possibility for reversing this process and inducing apoptosis is a cellular mechanism that enables selective pro-survival gene silencing, called RNA interference (RNAi). This mechanism promotes messenger RNA (mRNA) degradation using small interfering RNAs (siRNAs) [6,7,8]. For this reason, siRNA is under investigation for use in gene therapy [9]

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Results

Discussion

Conclusion