ABSTRACT
Objective To modify polyethyleneimine (PEI) by using Poloxamer 188 (P188) , and evaluate its related feature as carriers of genes in vitro. Methods PEI was modified through conjugating one hydroxyl group of P188 to the amino group of PEI by carbonate method. Structural analysis of synthesized polymer was performed by using 1H-NMR. The particle size and Zeta potential of synthesized polymer /DNA complexes were measured. The cytotoxicity of the complexes was evaluated using MTT method in MCF-7 cells, HeLa cells and HepG2 cells. The pGL3-lus was used as a reporter gene, and the transfection efficiency of complexesat HeLa cells was evalutated by measuring activity of luciferase. Results The result of 1H-NMR showed the purity of these synthesized polymers was high. The particle size of complexes were decreased with the increment of N /P ratios. The Zeta potential of complexes increased with the increment of N /P ratios. The cytotoxicity of the complexes increased with the increment of N /P ratios. The synthesized polymers showed lower cytotoxicity than unmodified PEI. The new synthesized polymers had maintained the high transfection efficiency at high N /P ratios. In particular, the optimal transfection efficiency of (P188) 1- PEI (N /P = 24) was significantly higher than that of PEI (N /P = 6) . Conclusion The P188 modifed PEI can serve as a effective non-viral gene carriers to transfect Hela cells.
ABSTRACT
Objective: To synthesize a new type of cationic polymers (β-ammo esters) (PBAE) and to study its role as a gene vector. Methods: PBAE was synthesized by the Michael addition reaction. PBAE/pDNA complex nanoparticles were prepared by self-assembly, and the gene tranfection efficiency mediated by the nanoparticles into HEK293 cells in vitro was observed. Results: When weight ratio of PBAE/pDNA was 50: 1, pDNA was completely wrapped. And the transfection efficiency of PBAE/pDNA nanoparticles (PBAE/pDNA weight ratio being 200: 1) was significantly higher than PEI/pDNA nanoparticles (43.3% ± 3.7% vs 30.3% ± 2.1%, P < 00.05). Conclution: Cationic poly(β-amino esters) can electrostatically bind to and condense anionic DNA into nanometersized parties. PBAE/pDNA nanopartides has a high transfection efficiency in in vitro transfection experiments.