Ternary nanoparticles of anionic lipid nanoparticles/protamine/DNA for gene delivery

In this study, the lipid nanoparticles with excellent cellular uptake capacity were utilized to prepare lipid nanoparticles/protamine/DNA ternary nanoparticles for gene delivery. Anionic lipid nanoparticles consisting of monostearin (MS) and different content of oleic acid (OA) were prepared. The lipid nanoparticles had an average size ranging from 23.6 to 71.3 nm and a zeta potential about −30 mV. The protamine/DNA complex was prepared by mixing the DNA and protamine solution with 1:2 mass ratio. The average size of protamine/DNA complex was 128.5 nm and with 19.4 mV zeta potential. Lipid nanoparticles/protamine/DNA ternary nanoparticles were then prepared by combining the protamine/DNA binary complex with lipid nanoparticles. The ternary nanoparticles had an average size ranging from 192.7 to 260.6 nm and were negatively charged. Gene transfection efficiency was improved by increasing OA content in lipid nanoparticles. Results of cellular uptake showed that the uptake ability of lipid nanoparticles was enhanced by increasing the OA content. Lipid nanoparticles with 20 wt% OA/protamine/DNA ternary nanoparticles (w/w/w, 65:6:3) showed the best and the most durable gene transfection even in the presence of serum.