Preparation of galactosylated chitosan/tripolyphosphate nanoparticles and application as a gene carrier for targeting SMMC7721 cells

Nanoparticles composed of galactosylated chitosan (GC) and tripolyphosphate (TPP) were prepared and their application as potential gene carriers for targeting SMMC7721 cells was investigated. The results showed that at certain pH (5.5–6.2) of GC solutions, small and stable nanoparticles were obtained at an optimal weight ratio of 5:1 (GC/TPP). Transmission electron microscope (TEM) revealed formation of spherical particles. The optimal pH of cell culture environment for transfection was from 6.4 to 6.7, which was the same pH as the polymer complex formation of GC/TPP solutions. The charge ratio of GC/TPP to DNA (N/P) at 10:1, 20:1 and 30:1 were checked for transfection and under optimized conditions, the GC/TPP-DNA nanoparticles successfully transfected 6.8% of the SMMC7721 cells as represented by overexpression of enhanced green fluorescent protein (EGFP), which showed a much more higher efficiency when compared to 0.6% of GC/DNA transfection under the same conditions. The presented results indicate that the GC/TPP nanoparticles might be very attractive to be used as a gene delivery carrier for hepatocyte targeting, thus warranting further in vivo or clinical investigations.