Synthesis Of The Functional Complexes Based On The Polyethyleneimine Derivatives And Study On Their Properties As Gene Vectors

Among the non-viral gene vectors,the gene transfection efficiency of polyethyleneimine?PEI?is extremely high.However,its cytotoxicity is still pretty high,and needed to be optimized.Here,we constructed two kinds of gene carrier based on PEI.In the first system,cyclodextrin?CD?was used to crosslink low molecular weight?LMW?PEI to gain PEI-CD.Meanwhile,azobenzene?Az?was used to modify polyethylene glycol?PEG?to get PEG-Az.Light-responsive PEI-CD/PEG-Az/DNA complexes were built through host-guest interaction.The zeta-potential of polyplex showed that the introduction of PEG can effectively reduce the zeta-potential of complex nanoparticles,but failed to make PEG detach completely under photoirradiation.Therefore,glutathione?GSH?-responsive disulfide linkage was employed as the connection between Az and PEG to construct PEI-CD/PEG-SS-Az/DNA gene carrier.The dual functions of light and glutathione?GSH?were subjected to complete PEG detachment.In the second system,we synthesized benzene boric acid?PBA?modified PEI(PEI₂₅₀₀₀-PBA),as well as tetrakis?4-carboxyphenyl?ethylene?TPE-?COOH?4?crosslinked PEI(PEI₁₈₀₀-TPE),followed by being mixed with DNA to obtain PEI₁₈₀₀-TPE/PEI₂₅₀₀₀-PBA/DNA complex nanoparticles.PBA possesses the membrane targeting property,which can promote cellular uptake.At the same time,the aggregation-induced emission?AIE?property of TPE derivatives can track the behavior of the vector in the cells which made the transfection mechanism become visible.