Delivery of plasmid DNA through nanoencapsulation

Abstract

After more than 50 years of investigations, gene therapy has become one of the most promising options for treating genetic diseases. The advances in polymer-based specifically polycation-based, DNA delivery systems have been proven to be effective alternatives to viral vectors, providing a large therapeutic material loading capacity, ease of scaling-up the production capacity and reduced immunogenicity. In this study, previously reported potential delivery carriers polycations such as poly-ethylenimine (PEI), poly-L-ornithine (PLO) and poly(N-(N-(2-aminoethyl)-2-aminoethyl) aspartamide) (Pasp(DET)) have been assessed by complexing with plasmid DNA (pDNA) at different mass ratios using dynamic light scattering (DLS) for the particle size characterization, electrophoretic light scattering techniques to characterize the particle surface charge or zeta potential and flow cytometry to evaluate the transfection efficiency and cytotoxicity in vitro. The pDNA/PEI polyplex displayed a 95.5% transfection efficiency at mass ratio 1:4 using 1 μg of pDNA, with a particle size and surface charge of approximately 115 nm and 36 mV. The pDNA/Pasp(DET) polyplex displayed a 98.8% transfection efficiency at mass ratio 1:60 using 1 μg of pDNA, with a particle size and surface charge of approximately 120 nm and 39 mV, whereas the pDNA/PLO polyplex showed the inability to efficiently deliver pDNA under any conditions. In conclusion, the biodegradable polyplex pDNA/Pasp(DET) has proven to be an effective and low cytotoxic alternative in delivering pDNA to previously known polycations which displayed toxicity problems at higher concentrations, such as PEI.