Brome mosaic virus-like particles as siRNA nanocarriers for biomedical purposes.

Alfredo Nuñez-Rivera,Danna L Arellano,Ana G Rodriguez-Hernandez,Pierrick G J Fournier,Ruben D Cadena-Nava,Rafael Vazquez-Duhalt

doi:10.3762/bjnano.11.28

Abstract

There is an increasing interest in the use of plant viruses as vehicles for anti-cancer therapy. In particular, the plant virus brome mosaic virus (BMV) and cowpea chlorotic mottle virus (CCMV) are novel potential nanocarriers for different therapies in nanomedicine. In this work, BMV and CCMV were loaded with a fluorophore and assayed on breast tumor cells. The viruses BMV and CCMV were internalized into breast tumor cells. Both viruses, BMV and CCMV, did not show cytotoxic effects on tumor cells in vitro. However, only BMV did not activate macrophages in vitro. This suggests that BMV is less immunogenic and may be a potential carrier for therapy delivery in tumor cells. Furthermore, BMV virus-like particles (VLPs) were efficiently loaded with small interfering RNA (siRNA) without packaging signal. The gene silencing was demonstrated by VLPs loaded with siGFP and tested on breast tumor cells that constitutively express the green fluorescent protein (GPF). After VLP-siGFP treatment, GFP expression was efficiently inhibited corroborating the cargo release inside tumor cells and the gene silencing. In addition, BMV VLP carring siAkt1 inhibited the tumor growth in mice. These results show the attractive potential of plant virus VLPs to deliver molecular therapy to tumor cells with low immunogenic response.

Highlights

Despite many efforts taken, the efficient and specific delivery of therapeutic molecules to tumor cells is still a unsolved challenge
In order to test the cell internalization of virus-like particles (VLPs), brome mosaic virus (BMV) and chlorotic mottle virus (CCMV) VLPs were loaded with NanoOrange, a hydrophobic fluorescent dye
We demonstrate that the BMV and CCMV capsids are efficiently internalized by breast tumor cells, without the need to couple a specific cell ligand

Summary

Introduction

The efficient and specific delivery of therapeutic molecules to tumor cells is still a unsolved challenge. Important BMV VLPs properties of biomedical interest are demonstrated, such as biocompatibility, tumor cell internalization, and their efficiency as nanocarriers for siRNA delivery. The NanoOrange-loaded BMV and CCMV capsids were incubated in MCF-7 cell cultures for 4 h to evaluate their internalization into the breast cancer cells.

Results

Conclusion