Transfection efficiency charge ratio

A number of experimental in vivo gene therapy trials on animals using PAMAM dendrimers are in their preliminary stages. Numerous in vivo experiments are currently being conducted in order to optimize the dendrimer generation, concentration, and complex charge ratio to obtain optimal transfection efficiency. 

Figure 6 Lipofection results (lipofection profiles) of lipoplexes from the R-configu-rated cationic lipids KL-1-1 to KL-1-17 (Table 1) in a mixture with equimolar amounts of l,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE) (counterion chloride) and the pCMVluc-plasmid. Each bar represents the mean ( S.D.) of three wells of a 96-well microtiter plate. T-axis (left) represents the transfection efficiencies expressed in relative light units (RLU) (lu/pg protein). X-axis (right) represents the viability of the cells compared to nontreated control cells. F-axis represents the different cationic lipid/plasmid DNA-charge ratios from 1 to 15.

We have mapped the transfection efficiency of DL/DOPC-DNA complexes as a function of molar fraction of DL (cPDL) and the cationic lipid/DNA charge ratio (Pchg)- As observed for DOTAP and multivalent lipids with valencies up to +5, TE... 

Liposome-mediated gene delivery is dependent on numerous factors, such as, the formulation of the liposomes including the cationic lipid/neutral lipid ratio, how the liposomes are prepared, the cationic liposome/DNA charge ratio of the complex of cationic liposome and DNA (lipoplex), and the method used to produce the lipoplex. Recently, it was reported that the way in which a liposome was prepared affected transfection efficiency (1), and formation method of lipoplex affected size of lipoplex in which large ones increased the efficiency of transfection (2-7). 

Fig. 3. Transfection efficiency of ML (DC-Choi/DOPE=1 2,1 1,2 1) iipopiexes formed by direct mixing at a charge ratio (+/-) of 3 in A549 ceiis. Lipopiexes were diiuted with RPMi-1640 containing FBS to a finai concentration of 1 ag of DNA in 0.5 mL of medium per weii, and the ceiis were incubated for 24 h in the medium...

Fig. 5. Change of size and transfection efficiency of lipoplexes formed by dilution method. Size of ML and DL after dilution in optiMEM within 5 min (a), size of their lipoplex after incubation in optiMEM within further 20 min (b), and transfection efficiency of lipoplexes in HeLa cells (c). Lipoplexes at a charge ratio (+/-) of 2 for ML and DL (DC-Chol DOPE=3 2,1 2), and of 7 for ML and DL (DC-Chol) from the results in Fig. 4. Transfection condition was the same with Fig. 4. Each result represents the mean SD(n= 3). P< 0.05. P< 0.01 by ANOVA test...

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