Efficient gene transfection using chitosan–alginate core-shell nanoparticles

Reverse microemulsion was used as a template to fabricate chitosan–alginate core-shell nanoparticles encapsulated with enhanced green fluorescent protein (EGFP)-encoded plasmids. The average size of DNA-entrapped nanoparticles measured by dynamic light scattering was increased proportionally, with the N/P ratios ranging from 5 to 20. These alginate-coated chitosan nanoparticles endocytosed by NIH 3T3 cells trigged swelling of transport vesicles which render gene escape before entering digestive endolysosomal compartment and concomitantly promote gene transfection rate. Results showed that DNA-encapsulated chitosan–alginate nanoparticles with average size of 64 nm (N/P ratio of 5) could achieve the level of gene expression comparable with the one obtained by using polyethyleneimine–DNA complexes.