Correlation Between Partical Formation Environments And BDCP/plasmid Complexes' Physical Properties And Toxicity

Cationic polymer-based non-viral vector is one of the most common gene carrier systems used in both in vitro and in vivo gene delivery and gene therapy.However,the effects of particle formation environments on carrier-DNA particle physical properties and on their subsequent delivery performances remain unclear.In present studies,we selected two cationic polymers as study models:PEI(M.W.25k),a most common cationic polymer,and BDCP,a PEI 600 based polymer with biodegradable bond, developed by Nitto Denko Technical Corp,a collaboration research institute in US.The physical properties of polymer/DNA complex prepared in varied ion conditions such as particle size,zeta potential,affinity were measured and the transfection efficiency was conducted in various cell lines.The hemolysis toxicity was performed in freshly prepared RBC samples.Our data indicate(1)cationic carrier/DNA physical properties such as particle size,affinity,and gene transfection efficiency were affected by ionic strength;(2)at the rage of pH5.5～8.5,whether it is acid or base of the solution where the BDCP/DNA complexes formed make little effect on complexes physical properties and gene transfection or cytotoxicity;(3)the effect of different solution on physical properties, gene delivery efficiency and cytotoxicity was similar between BDCP and PEI at tested conditions;(4)ionic buffer such as PBS was favorable to achieve improved stability,high gene delivery efficiency and low hemolysis effect,our current work provides valuable information regarding ionic strength on cationic polymer assisted gene delivery, which will help to determine application condition either in vitro or in vivo.