摘要
Design and development of efficient non-viral gene delivery systems is critical to overcome various barriers for effective intracellular gene delivery.Eight new spermine-based protonatable surfactants were designed,synthesized and evaluated as non-viral pH-sensitive gene carriers.These carriers formed stable complexes with plasmid DNA at an N/P ratio as low as 2.The sizes of the carrier/pDNA nanoparticles (N/P = 12) were in the range of 90–130 nm,smaller than that of Lipofectamine2000/pDNA nanoparticles.The pDNA nanoparticles of the carriers exhibited substantially increased hemolysis when pH decreased from 7.4 to 5.5.The DNA nanoparticles had low cytotocixity,similar to that of Lipofectamine-2000/pDNA nanoparticles.The pH-sensitive gene carriers with no helper lipids resulted in much higher intracellular transfection and gene expression in U87 cells than Lipofectamine-2000.[N,N′-Bis(oleoylcysteinyl)(β-alanyl-α-lysyl)]-spermine monoamide (SKACO) resulted in the highest luciferase transfection efficiency,more than 400 times higher than that of Lipofectamine-2000,and GFP expression in 71% of transfected U87 cells.SKACO was identified as a promising lead carrier for efficient gene delivery.These spermine-based pH-sensitive amphiphilic carriers have a potential to be further developed as efficient non-viral multifunctional gene delivery systems.
Design and development of efficient non-viral gene delivery systems is critical to overcome various barriers for effective intracellular gene delivery. Eight new spermine-based protonatable surfactants were designed, synthesized and evaluated as non-viral pH-sensitive gene carriers. These carriers formed stable complexes with plasmid DNA at an N/P ratio as low as 2. The sizes of the carrier/pDNA nanoparticles （N/P= 12） were in the range of 90-130 nm, smaller than that of Lipofectamine- 2000/pDNA nanoparticles. The pDNA nanoparticles of the carriers exhibited substantially increased hemolysis when pH decreased from 7.4 to 5.5. The DNA nanoparticles had low cytotocixity, similar to that of Lipofectamine-2000/pDNA nanoparti- cles. The pH-sensitive gene carriers with no helper lipids resulted in much higher intracellular transfection and gene expression in U87 cells than Lipofectamine-2000. [N,N＇-Bis（oleoylcysteinyl）（β-alanyl-α-lysyl）]-spermine monoamide （SKACO） resulted in the highest luciferase transfection efficiency, more than 400 times higher than that of Lipofectamine-2000, and GFP expression in 71% of transfected U87 cells. SKACO was identified as a promising lead carrier for efficient gene delivery. These spermine-based pH-sensitive amphiphilic carriers have a potential to be further developed as efficient non-viral multifunctional gene delivery systems.
