Characterization of liposome-mediated gene delivery: expression, stability and pharmacokinetics of plasmid DNA

Abstract

We have characterized a new synthetic gene delivery sysplasmid DNA could be detected in blood cells up to 1 h tem, termed DLS, which may be suitable for systemic gene after injection. Systemic administration of DLS-DNA therapy. DLS constitutes a lipopolyamine and a neutral yielded transgene expression in mouse tissues, such as in lipid and associated plasmid DNA in the formation of lamellung or liver. The ratio of DLS:DNA and the procedure used lar vesicles (DLS-DNA). The ratio of lipids and lipid to DNA to form DLS-DNA affected both the level and cellular as well as the method of preparation were optimized to specificity of expression of a luciferase reporter gene yield a high in vitro transfection efficiency compared with showing that in vitro transfection efficiency of DLS-DNA that previously reported for cationic lipid systems. DLSformulations cannot be easily extrapolated to an in vivo set-DNA showed a rapid cellular uptake and distribution in the ting. Optimization of the formulation of a DNA delivery syscytoplasmic and nuclear (especially in the nucleoli) comtem was critical to obtain a defined structure resulting in a partments as determined by laser-assisted confocal preparation with high reproducibility and stability, greater microscopy. There was little or no plasmid DNA degrahomogeneity of particle size and high efficacy following dation over a period of 20 min, relatively slow plasma clearsystemic gene transfer. In addition, the DLS system may ance, and effective and rapid cellular uptake of DLS-DNA be formulated for specific target tissues and may have a following intravenous administration in mice. Supercoiled wide range of applications for gene therapy.Keywords: gene transfer; liposomes; plasmid DNA; biodistribution; pharmacokinetics Synthetic gene transfer vectors are receiving increasingIntroduction study as an alternative to viral vectors since this strategy One of the main impediments to successful gene therapy appears to be safe. Potential methods of gene delivery is the generally poor efficiency of DNA delivery. Most that could be employed include the pneumatic DNA gene therapy efforts involve the use of retroviral vectors gun, 4 DNA-protein complexes 5 or lipidic particles. 6 The because of the usual efficient cell entry and stable intetypical genetic material delivered to target cells by these gration of the gene. Clinical use of retroviral vectors, methods are plasmids, although antisense oligonucleohowever, is hampered by safety issues.1-3 A first concern tides are currently being tested as well. 8 Plasmid prepis the possibility of generating an infectious wild-type arations are simple, quick, safe, inexpensive and may be virus following a recombination event. A second concern applied in combination with a synthetic carrier. Thereis the consequence of random integration of the viral fore, gene therapy by this means may be safe, durable sequence into the genome of the target cell which may and used as a drug-like therapy. The successful use of lead to a tumorigenic or a cytotoxic event. ...

Transfection of cultured myoblasts in high serum concentration with DODAC:DOPE liposomes

“…The few reports that have dealt with the use of cationic liposomes to transfect cultured muscle cells obtained significant transfection levels only in a serumfree environment. 9,13,18,19 We and others have shown that the efficiency of liposome-DNA complexes (lipoplexes) is drastically inhibited by the presence of serum 9,11,13 and that DNA precondensation with polylysine (lipopoliplexes) can partially correct this inhibition. 9 However, the experiments reported so far were carried out at most in the presence of 10% serum, a condition that is far from that present in vivo, and the transfection levels were extremely low.…”

“…To date, all liposome formulations reported have transfection efficiencies that are severely affected by serum in the medium and consequently transfection of cultured cells with cationic liposomes has been carried out in serum-free conditions or at most in 10-15% serum. [8][9][10][11][12] A liposome formulation with a transfection efficiency that is not inhibited by serum in the extracellular environment would provide a considerable advance toward the goal of systemic delivery.…”

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

“…[8][9][10][11] Systemic delivery by intravenous injection has also been shown to be effective in transfecting lung tissue. [12][13][14][15][16][17][18] Polycationic polymers, like polyethylenimine (PEI), are a new class of nonviral vectors capable of transfecting in vitro and in vivo a variety of cell types, including respiratory cells. [19][20][21][22][23] Previous intravenous studies have not directly compared cationic lipids and polymers in transfecting animal model airways.…”

hTERT/re-caspase-3 system induce apoptosis in hTERT-positive

“…35 The other is nonviral vectors, but the generally poor efficiency of delivery and expression by nonviral systems are limitations in the development of gene therapy. 36 So, current research of nonviral vectors focused on the complexes of nucleic acids with cationic polymers, i.e., polyplexes 35 hTERT/re-Caspase-3 Induce Apoptosis a n d based o n cationic lipids, i.e., lipoplexes. 37,38 However, these systems deliver DNA as a bolus, without long-term sustained release.…”