Effects of Decomplexation Rates on Ternary Gene Complex Transfection with α-Poly(l-Lysine) or ε-Poly(l-Lysine) as a Decomplexation Controller in An Easy-To-Transfect Cell or A Hard-To-Transfect Cell

Abstract

The tight binding of pDNA with a cationic polymer is the crucial requirement that prevents DNA degradation from undesired DNase attack to safely deliver the pDNA to its target site. However, cationic polymer-mediated strong gene holding limits pDNA dissociation from the gene complex, resulting in a reduction in transfection efficiency. In this study, to control the decomplexation rate of pDNA from the gene complex in a hard-to-transfect cell or an easy-to-transfect cell, either α-poly(l-lysine) (APL) or ε-poly(l-lysine) (EPL) was incorporated into branched polyethylenimine (bPEI)-based nanocomplexes (NCs). Compared to bPEI/pDNA NCs, the addition of APL or EPL formed smaller bPEI-APL/pDNA NCs with similar zeta potentials or larger bPEI-EPL/pDNA NCs with reduced zeta potentials, respectively, due to the different characteristics of the primary amines in the two poly(l-lysine)s (PLs). Interestingly, although both bPEI-APL/pDNA NCs and bPEI-EPL/pDNA NCs showed similar pDNA compactness to bPEI/pDNA NCs, the addition of APL or EPL resulted in slower or faster pDNA release, respectively, from the bPEI-PL/pDNA NCs than from the bPEI/pDNA NCs. bPEI-EPL/pDNA NCs with a decomplexation enhancer (i.e., EPL) improved the transfection efficiency (TE) in both a hard-to-transfect HepG2 cell and an easy-to-transfect HEK293 cell. However, although a decomplexation inhibitor (i.e., APL) reduced the TE of bPEI-APL/pDNA NCs in both cells, the degree of reduction in the TE could be compensated by PL-mediated enhanced nuclear delivery, particularly in HepG2 cells but not HEK293 cells, because both PLs facilitate nuclear localization of the gene complex per its cellular uptake. In conclusion, a decomplexation rate controller could be a potential factor to establish a high TE and design clinically available gene complex systems.

Arginine and Histidine-modified Layered Double Hydroxides Facilitate Transgene Expression in Cancer Cells in Vitro

“…The differences in cell membrane properties of the different cell lines [58] could also affect cellular uptake. The low transfection levels for HepG2 cells can be expected as these cells have a reputation of being a difficult-to-transfect cell line [59], as they often grow in clumps that hinder transfection. The low level of transfection for the pDNA:MgAl 0.25 complex could result from the large size of the pDNA:MgAl 0.25 complex and the possibility of aggregation caused by the pDNA complexing several LDH nanoparticles.…”

First direct evidence for direct cell-membrane penetrations of polycationic homopoly(amino acid)s produced by bacteria

“…Polymer 1 shows potent antimicrobial activities and nondetectable levels of cytotoxicity 1,2 , in addition to proteolytic resistance due to the isopeptide-bond linkages between its α-carboxyl groups and ε-amino groups 22 . Recent studies reported that 1 showed potential enhancements of the cellular uptakes of its electrostatic counterparts, i.e., DNA [23][24][25][26] , siRNA 27 , and drug microcapsules [28][29][30][31] . However, the cationic charges of 1 were mostly neutralized by the anionic counterparts in their complex forms, raising the question of how 1 carries its anionic cargoes into cells.…”