Abstract

Effective delivery of nucleic acids into the cells holds great potential for vaccine development and cancer treatments. N4 Pharma has been developing Nuvec® – a unique non-viral delivery system for the effective delivery of nucleic acids into the cells. Nuvec silica nanoparticles have a unique irregular (spiky) surface structure, coupled with polyethyleneimine (PEI), that simply and effectively traps and protects nucleic acids as it travels into the cells. Here, we carried out biological characterisation of Nuvec particles using a range of methods. We determined the size, zeta potential and DNA/RNA loading capacity of different size Nuvec particles using DLS, zeta sizer and mass spectrometry respectively. Next, we determined the transfection efficiency of Nuvec at different Nuvec:nucleic acid ratios using live cell imaging and flow cytometry methods. Furthermore, we demonstrated that Nuvec particles protect the mRNA from degradation even after lyophilisation by analysing transfection efficiency of lyophilized mRNA:Nuvec complex. Additionally, we studied the cellular internalisation of Nuvec using high resolution microscopy. We analysed 3D reconstructed microscopy images and quantified the number of Nuvec particles inside the cells. Finally, we studied the mechanism of cellular internalisation in HEK293T cells upon inhibition of different endocytosis pathways. Our data demonstrates that Nuvec particles provide protection of RNA/DNA, efficiently deliver DNA/RNA into the cells and result in protein expression. Furthermore, our data provides insights into the mechanisms involved in the cellular uptake of Nuvec particles. Altogether our finding provide guidance for the rational design of Nuvec for efficient gene delivery applications.