Complexation of plasmid DNA and poly(ethylene oxide)/poly(propylene oxide) polymers for safe gene delivery

Gene deliveryis the process of introducing foreign genetic material, such asDNAorRNA, into hostcells. Gene therapyutilizes gene delivery to deliver genetic material with the goal of treating a disease or condition in the cell.Actual viral vectors may have side effects, while actual systems using metal nanoparticles for gene delivery are toxic. Therefore, we designed here a biocompatible tri-block copolymer PEO20-PPO69-PEO20 as a gene delivery vector [PEO: poly(ethylene oxide); PPO: poly(propylene oxide)]. We studied the conjugation of PEO20-PPO69-PEO20 and DNA using various techniques. Results of gel retardation assay along with zeta potential and dynamic light scattering provide evidence of DNA sequestration. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy show that the PO43- groups of plasmid DNA are primarily involved during nanoconjugate construction. The integrity and functionality of plasmid DNA within the cellular environment is further demonstrated by the expression of green fluorescent protein gene in Escherichia coli. Overall, our findings support the use of block copolymers as delivery systems for mammalian and plant cells.