Filamentous Condensation of DNA Induced by Pegylated Poly-l-lysine and Transfection Efficiency

Abstract

In this paper we propose a detailed analysis of structural and morphological properties of two poly-L-lysine (PLL)-based transfection formulations, PLL/DNA and pegylated PLL (PLL-g-PEG)/DNA, by means of atomic force microscopy (AFM) and transmission electron microscopy (TEM). Comparing PLL-g-PEG/DNA with PLL/DNA polyplexes, we demonstrate that, due to the presence of PEG, the particles differ not only in size, shape, and crystalline structure, but also in transfection efficiency. While PLL condensates DNA in large agglomerates, PLL grafted with polyethylene glycol 2000 can condensate DNA in long filaments with diameters of some nanometers (6-20 nm). These structures are dependent on the grafting ratio and are more efficient than compacted ones, showing that DNA uptake and processing by cell is directly related to physicochemical properties of the polyplexes.

Potent calcium phosphate nanoparticle surface coating for in vitro and in vivo siRNA delivery: a step toward multifunctional nanovectors

“…Nucleic acid complexes with various polymers can be visualized by TEM imaging aer uranyl acetate coloration. 22 Careful observation was made to detect the presence of PEIY/siRNA non-associated with calcium phosphate particles. No PEIY/siRNA complexes were detected.…”

Polycationic Nanoparticles: (1) Synthesis of a Polylysine-MION Conjugate and its Application in Labeling Fibroblasts

“…This approach introduces complications in the synthesis of the final product including crosslinking of the dextran coat and has yielded few examples of successful reproduction in the hands of other investigators [9,22,32]. The use of transfection agents such as polylysine to facilitate entry of compounds into cells is well documented [34][35][36][37].…”

Secondary structure of end group functionalized oligomeric-l-lysines: investigations of solvent and structure dependent helicity

“…8 Especially amphiphilic peptide-conjugates, 9 that are prone to aggregation, display brillation via nucleation dependent aggregation mechanisms. Poly-L-lysine (PLL) in particular has received signicant attention in the eld of biomedicine, [10][11][12][13][14][15][16] as it possesses inter-and intra-molecular folding behaviour, where its subsequent assembly can lead to complex, oen even brillar-like structures. Thus, dynamic conformational changes of PLL depends on various external chemical and physical conditions having been studied both in solution and in the solid state, with an unclear contribution of end groups and chain length.…”