Vectors based on reducible polycations facilitate intracellular release of nucleic acids

Read, Martin; Bremner, K. Helen; Oupický, David; Green, Nicola K.; Searle, Peter F.; Seymour, Leonard W.

doi:10.1002/jgm.331

Cited by 147 publications

(106 citation statements)

References 50 publications

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“…When transfecting cells with low NADPH/H ϩ levels with lPEI polyplexes as a control, the efficacy was not affected at any time point (data not shown). Therefore, from the literature and our results, we conclude that the polyplexes may at least partially undergo an NADPH/H ϩ -dependent, and therefore GSH-dependent, reduction inside the cell (28)(29)(30). The data in Fig.…”

Section: Resultssupporting

confidence: 73%

Breaking up the correlation between efficacy and toxicity for nonviral gene delivery

Breunig

Lungwitz

Liebl

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

404

322

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Nonviral nucleic acid delivery to cells and tissues is considered a standard tool in life science research. However, although an ideal delivery system should have high efficacy and minimal toxicity, existing materials fall short, most of them being either too toxic or little effective. We hypothesized that disulfide cross-linked lowmolecular-weight (MW) linear poly(ethylene imine) (MW <4.6 kDa) would overcome this limitation. Investigations with these materials revealed that the extracellular high MW provided outstandingly high transfection efficacies (up to 69.62 ؎ 4.18% in HEK cells). We confirmed that the intracellular reductive degradation produced mainly nontoxic fragments (cell survival 98.69 ؎ 4.79%). When we compared the polymers in >1,400 individual experiments to seven commercial transfection reagents in seven different cell lines, we found highly superior transfection efficacies and substantially lower toxicities. This renders reductive degradation a highly promising tool for the design of new transfection materials.biodegradable ͉ polyethylenimine ͉ nucleic acid ͉ disulfide bond ͉ transfection G ene transfer into cells has become a standard procedure in life science research. Nonviral carriers have gained in importance in recent years because of their safety in handling and ease of application compared with viral vectors. Browsing databases such as PubMed or Chemical Abstracts reveals that almost every publication related to genetics, biochemistry, molecular biology, developmental biology, or neurology incorporated lipid-or polymer-based transfection as a pivotal tool for the investigation of various cellular processes. Therefore, it appears that the delivery of nucleic acids is a well established method for the transfection of mammalian cells, and, given the amount of research data that has been produced, one would assume that the procedures for nonviral transfection would be well optimized. A closer look at the contemporary literature, however, reveals that doubts seem justified. Contemporary transfection reagents are almost universally toxic because of their cationic or amphiphilic character (1-4).The dilemma that we face is exemplified by considering the polymeric transfection agent poly(ethylene imine) (PEI). Since its introduction in 1995, PEI has been considered the gold standard for polymer-based gene carriers because of the relatively high transfection efficacy of its polyplexes (complex of nucleic acid and polymer) (5, 6). However, it has been shown that both the efficacy and toxicity of PEI are strongly correlated with its molecular weight (MW) as well as its structure (branched or linear: bPEI or lPEI, respectively) (7-17). Efficacy and adverse reactions seem thereby to be strongly associated. PEI is not the only material that suffers from this ''malignant'' correlation. Nonviral transfection seems like choosing between Scylla and Charybdis: either a high transfection efficacy, which is associated with a devastating toxicity, or a low efficacy, which does not affect the cell viability at ...

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Section: Resultssupporting

confidence: 73%

Breaking up the correlation between efficacy and toxicity for nonviral gene delivery

Breunig

Lungwitz

Liebl

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

404

322

View full text Add to dashboard Cite

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“…Compared with the extracellular space, the concentration of GSH was at a level (2-20 mM) high enough to generate relatively high redox potential to destabilize disulfide bond and degrade polyplexes. 32 As shown in our study, the GSH inhibitor BSO limited the fracture of the disulfide bond and then decreased the transgene expression efficiency of the polyplexes.…”

supporting

confidence: 60%

Reducible chimeric polypeptide consisting of octa-d-arginine and tetra-l-histidine peptides as an efficient gene delivery vector

Wang¹,

Tai²,

Tian³

et al. 2015

IJN

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Cationic oligopeptide as a nonviral gene delivery vector has aroused much research interest recently, but its further application is limited by its low transfection efficiency. In the present study, we have created a high-efficiency gene vector by using octa- d -arginine and tetra- l -histidine to form a disulfide cross-linked chimeric polypeptide and used this vector to deliver the therapeutic gene tumor-necrosis-factor-related apoptosis-inducing ligand ( TRAIL ) to see whether the gene could be transferred and could exert antitumor effects in vitro and in vivo. The result showed that the newly designed vector was able to condense DNA into nanosized polyplexes effectively, thus facilitating its transmembrane transport, promoting its endosomal escape, and finally enabling degradation within the cell. Our study has demonstrated that this chimeric polypeptide is an effective gene carrier in cancer therapy.

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“…The rPLL and PLL polycations had similar average molecular weights (∼30,000), although the PLL was less polydisperse than rPLL. Both polycations formed complexes with similar size [38,51] and surface charge and thus permitted a fairly direct evaluation of the effects of redox-sensitive properties of complexes in Bcl-2 expressing cells. A limitation of the selected polycations is the requirement for a lysosomotropic agent to improve their transfection activity.…”

Section: Discussionmentioning

confidence: 99%

“…A limitation of the selected polycations is the requirement for a lysosomotropic agent to improve their transfection activity. We therefore followed a previously published strategy to improve endosomal escape of the complexes [51]. Complexes were first prepared by mixing the polycations with the respective nucleic acid, and that was followed by formation of ternary complexes with DOTAP.…”

Section: Discussionmentioning

confidence: 99%

Overexpression of Bcl-2 as a proxy redox stimulus to enhance activity of non-viral redox-responsive delivery vectors

et al. 2008

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Redox-sensitive non-viral delivery systems exploit intracellular reducing environment to improve the efficacy of the delivery of nucleic acids by selectively releasing the cargo in the subcellular space. Bcl-2 overexpression is frequently observed in human cancers and is closely associated with increased resistance to chemotherapy and radiotherapy. One of the biochemical alterations accompanying Bcl-2 overexpression is the increase in cellular glutathione (GSH) levels. In this study, we hypothesize that such increase of GSH concentrations will selectively enhance the transfection activity of redox-sensitive delivery systems in cells overexpressing Bcl-2. Transfection studies were conducted in MCF-7 mammary carcinoma cells and MCF-7 clones overexpressing Bcl-2. It was confirmed that Bcl-2 overexpression resulted in the expected increase in GSH concentrations. Redoxsensitive complexes containing plasmid DNA, mRNA, antisense oligodeoxynucleotides, and siRNA exhibited selectively increased activity in cells overexpressing Bcl-2 compared to non-redox complexes. The effect of Bcl-2 overexpression on the selective enhancement of transfection was highly dependent on the type of the delivered nucleic acid, and was most pronounced for mRNA. This study shows that Bcl-2 overexpression can serve as a proxy redox stimulus to enhance the activity of all major classes of potential nucleic acid therapeutics, when delivered using redoxsensitive vectors.

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Vectors based on reducible polycations facilitate intracellular release of nucleic acids

Abstract: These results demonstrate that lipid-mediated activation of RPC-based polyplexes is a useful strategy to enhance intracellular delivery of nucleic acids and potentiate therapeutic activity.

Cited by 147 publications

References 50 publications

Breaking up the correlation between efficacy and toxicity for nonviral gene delivery

Breaking up the correlation between efficacy and toxicity for nonviral gene delivery

Reducible chimeric polypeptide consisting of octa-d-arginine and tetra-l-histidine peptides as an efficient gene delivery vector

Overexpression of Bcl-2 as a proxy redox stimulus to enhance activity of non-viral redox-responsive delivery vectors

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