Enhanced transfection of polyplexes based on pluronic-polypropylenimine dendrimer for gene transfer

Abstract

Third generation cationic dendritic polymeric polypropyleneimine (PPI) was modified by Pluronic P123 and investigated for gene delivery. The cytotoxicity of P123-PPI was evaluated by the MTT assay and shown to be much lower than that of PPI alone. P123-PPI and PPI can both condense plasmid DNA into nanoparticles with a size of approximately 100 nm and a zeta potential of about 15 mV at the N/P ratio 20:1. The nanoparticles can protect plasmid DNA from being digested by DNase I at a concentration of 0.4 U/microg DNA. The nanoparticles were resistant to dissociation induced by 50% fetal bovine serum and 75 microg/mL sodium heparin. The transfection efficiency of SPC-A1 cells using P123-PPI/DNA nanoparticles was much higher than the transfection utilizing PPI/DNA nanoparticles. The addition of free P123 during the preparation of P123-PPI/DNA nanoparticles could significantly enhance the transfection efficiency in the presence of 10% fetal bovine serum. Therefore, P123-PPI/DNA complex nanoparticles may be a safe, efficient and promising cationic conjugate for gene delivery.

Coupling of a bifunctional peptide R13 to OTMCS-PEI copolymer as a gene vector increases transfection efficiency and tumor targeting

“…Sodium heparin can dissociate such complexes in a concentration-dependent manner. 29 As shown in Figure 6C, at a w/w ratio of 20, sodium heparin could dissociate the OTMCS-PEI-R13/DNA complex at a concentration of 500 µg/mL. The complexes were completely dissociated when the concentration exceeded 600 µg/mL.…”

“…In fact, under the same experimental conditions, DNA can be completely digested at a DNase I concentration of 0.08 U/µg DNA. 29 The stability of the OTMCS-PEI-R13/DNA complex in vivo was evaluated by treating the complex with serum and sodium heparin in vitro. As shown in Figure 6B, when DNA was coated completely by OTMCS-PEI-R13, there were no electrophoretic bands of DNA, so serum could not dissociate the OTMCS-PEI-R13/DNA complex even at a concentration of 50%.…”

Reversal of P-glycoprotein-mediated multidrug resistance by CD44 antibody-targeted nanocomplexes for short hairpin RNA-encoding plasmid DNA delivery

“…All of the animal experiments were performed according to the Guideline Principles evaluated and approved by the ethics committee of Fudan University. The synthesis of P123-PPI was reported in detail in our previous publication [50]. P123 was directly activated by an equal molar quantity of CDI without terminal hydroxyl group protection and then reacted with PPI [40].…”

“…P123-PPI was synthesized as a gene carrier with low toxicity and high gene transfection in MDR cancer cells according to our previously reported procedure [50]. In preliminary experiments, P123-PPI was synthesized at varying P123/PPI molar ratios through two methods [40,55]: non-single-terminal protection graft reaction (Fig.…”

Degradable copolymer based on amphiphilic N-octyl-N-quatenary chitosan and low-molecular weight polyethylenimine for gene delivery

“…Under the same experimental conditions, DNA was digested by DNase I at the concentration of 0.08 U DNase I/µg DNA. 26 Naked DNA is also easily digested by blood components. Serum and sodium heparin were used to evaluate the stability of OTMCS-PEI/DNA complexes in vivo.…”