Comparison between cationic polymers and lipids in mediating systemic gene delivery to the lungs

Abstract

Airway inflammation frequently found in congenital and mice efficiently transfected primarily the lungs and to a acquired lung diseases may interfere with gene delivery by lesser extent, heart, spleen, kidney and liver. The other direct administration through either instillation or aerosol.vectors mediated lower to undetectable levels of luciferase Systemic delivery by the intravenous administration repexpression in the lungs, with DOTAP Ͼ GL67/DOPE Ͼ PEI resents an alternative route of delivery that might bypass 25K Ͼ DOTMA/DOPE. A double injection protocol with a this barrier. A nonviral approach for transfecting various 15-min interval between the two doses of DOTAP/DNA airway-derived cell lines in vitro showed that cationic polycomplexes was investigated and showed a relevant role of mers (PEI 22K and 25K) and lipids (DOTAP, GL-67/DOPE) the first injection in transfecting the lungs. A two log are able to transfect with high efficiency the reporter genes increase in luciferase expression was obtained either when firefly luciferase and E. coli lacZ. Notably, two properties the two doses were comprised of luciferase plasmid or predicted that cationic vectors would be useful for a syswhen an irrelevant plasmid was used in the first injection. temic gene delivery approach to the lung: (1) transfectionThe double injection of luciferase/PEI 22K complexes was not inhibited or increased when cells were incubated determined higher transgene levels than a single dose, but with cationic lipids or polymers in the presence of serum; a clear difference using an irrelevant plasmid as first dose and (2) cationic vectors protected plasmid DNA from was not observed. Using lacZ as a reporter gene, it was DNase degradation. A single injection of DNA complexed shown that only cells in the alveolar region, including type II to the cationic polymer PEI 22K into the tail vein of adult penumocytes, stained positively for the transgene product.

Biodistribution and transgene expression with nonviral cationic vector/DNA complexes in the lungs

“…We have previously shown that a single injection of DNA complexed to the cationic polymer polyethylenimine (PEI) 22K into the tail vein of adult mice efficiently transfected primarily the lung and, to a lesser extent, heart, spleen, kidney, and liver. 13 As shown in Figure 1a, the other vectors seemed to mediate lower levels of luciferase expression in the lungs, with DOTAP Ͼ PEI 25K Ͼ GL-67A. The most positive complexes gave the highest luciferase levels in the lungs and the maximal activity was obtained with PEI 22K at 15 equivalents of amino-to-phosphate (N/P) groups (corresponding to 2.4 +/− charge ratio).…”

“…Intravenous injections of GFP-coding plasmid complexed with PEI 22K gave positive signal in the alveolar region comprising endothelial cells and pneumocytes (Figure 5a), confirming the previous observations with ␤-galactosidase transgene. 13 After an intratracheal injection, different cell targets were obtained with PEI 25K, PEI 22K, and GL-67A. PEI 25K complexes determined GFP positivity in bronchial cells (Figure 5c), with lower signal in the alveolar region (not shown).…”

“…8,9 Systemic intravenous infusion of cationic vector/DNA complexes has been attempted and shown to transfect preferentially the lung tissue. 7,[10][11][12][13] The most important determinants for cationic lipid-mediated gene transfer through intravenous administration are the cationic lipid structure, the charge ratio (+/−) between the cationic vector and DNA, [14][15][16] slightly positive PEI complexes as compared with DNA alone, whereas cationic lipid-based vectors, DOTAP and GL-67A, gave not significant luciferase activity. Both types of polyplexes gave similar levels of lung luciferase expression by targeting different airway cell populations.…”

Chitosan as a nonviral gene delivery system. Structure–property relationships and characteristics compared with polyethylenimine in vitro and after lung administration in vivo

“…The stability of complexed pDNA against DNase degradation was studied by incubation of chitosan and PEI polyplexes in the presence or absence of 8 U of DNase I as described previously. 63 The reaction was carried out for 1 h at 37°C followed by examination using the agarose gel retardation assay. pDNA obtained from the stock solution was used as control.…”

Gene delivery to the lung using protein/polyethylenimine/plasmid complexes

“…14,26,27 The rate of injection for HSA/PEI/DNA preparations was assessed using a range of injection times between 3 s (the minimum time necessary for a single smooth i.v. push injection of 200 l via tail vein) and 5-10 l pulse injections distributed over 30 s to 3 min.…”