A novel polyethyleneimine-coated adeno-associated virus-like particle formulation for efficient siRNA delivery in breast cancer therapy: preparation and in vitro analysis

Abstract

Wei Shao1, Arghya Paul1, Sana Abbasi1, Parminder S Chahal2, Jimmy A Mena2, Johnny Montes2, Amine Kamen2, Satya Prakash11Biomedical Technology and Cell Therapy Research Laboratory, Department of Biomedical Engineering and Artificial Cells and Organs Research Centre, Faculty of Medicine, McGill University, 2Animal Cell Technology, Bioprocess Centre, Biotechnology Research Institute, National Research Council, Montreal, Quebec, CanadaBackground: Systemic delivery of small interfering RNA (siRNA) is limited by its poor stability and limited cell-penetrating properties. To overcome these limitations, we designed an efficient siRNA delivery system using polyethyleneimine-coated virus-like particles derived from adeno-associated virus type 2 (PEI-AAV2-VLPs).Methods: AAV2-VLPs were produced in insect cells by infection with a baculovirus vector containing three AAV2 capsid genes. Using this method, we generated well dispersed AAV2-VLPs with an average diameter of 20 nm, similar to that of the wild-type AAV2 capsid. The nanoparticles were subsequently purified by chromatography and three viral capsid proteins were confirmed by Western blot. The negatively charged AAV2-VLPs were surface-coated with PEI to develop cationic nanoparticles, and the formulation was used for efficient siRNA delivery under optimized transfection conditions.Results: PEI-AAV2-VLPs were able to condense siRNA and to protect it from degradation by nucleases, as confirmed by gel electrophoresis. siRNA delivery mediated by PEI-AAV2-VLPs resulted in a high transfection rate in MCF-7 breast cancer cells with no significant cytotoxicity. A cell death assay also confirmed the efficacy and functionality of this novel siRNA formulation towards MCF-7 cancer cells, in which more than 60% of cell death was induced within 72 hours of transfection.Conclusion: The present study explores the potential of virus-like particles as a new approach for gene delivery and confirms its potential for breast cancer therapy.Keywords: adeno-associated virus type 2, virus-like particles, small interfering RNA delivery, breast cancer therapy, nanomedicine