Effective gene delivery based on facilely synthesized core-shell Ag@PDA @PEI nanoparticles

Introducing exogenous genes into target cells is one of the main strategies of gene therapy. Safe and effective gene vector is the guarantee to ensure the successful implementation of this strategy. In this work, firstly, a coating layer was formed on the surface of silver nanoparticles (AgNPs) by the self-polymerization of dopamine under weak alkaline conditions. Then, ternary nanoparticles (NPs) of Ag@PDA@PEI were prepared by PEI, grafting onto the surface of AgNPs by Michael addition reaction. Its physical and chemical properties were characterized by FTIR, SEM, TEM, TGA, elemental analysis, and AFM. The results showed that the ternary NPs have a particle size of about 25-100 nm and good stability. Its potential as gene vector was evaluated by the investigation of its cytotoxicity, DNA protection ability, cell uptake, and gene transfection efficiency. The results showed that Ag@PDA@PEI NPs can completely condensate DNA and protect DNA from degradation by DNase at low N/P ratio (0.72). The NPs showed no obvious cytotoxicity to cells and had no significant effect on cell growth curve. Ag@ PDA@PEI/pDNA complex can be efficiently ingested by cells and shows higher transfection efficiency than PEI/DNA complex. These results showed that Ag@PDA@PEI NPs have the potential to be developed and used as a safe and efficient gene vector.

Automated summary

This study developed ternary nanoparticles by coating silver nanoparticles with a polymeric layer of dopamine and grafting polyethyleneimine onto the surface. The nanoparticles showed good stability, low cytotoxicity, and high transfection efficiency, indicating their potential as safe and efficient gene vectors.