TY  - JOUR
A1  - Rumschöttel, Jens
A1  - Kosmella, Sabine
A1  - Prietzel, Claudia Christina
A1  - Appelhans, Dietmar
A1  - Koetz, Joachim
T1  - Change in size, morphology and stability of DNA polyplexes with hyperbranched poly(ethyleneimines) containing bulky maltose units
JF  - Colloids and surfaces : an international journal devoted to fundamental and applied research on colloid and interfacial phenomena in relation to systems of biological origin ; B, Biointerfaces
N2  - Polyplexes between Salmon DNA and non-modified hyperbranched poly(ethyleneimines) of varying molar mass, i.e., PEI(5 k) with 5000 g/mol and PEI(25 k) with 25,000 g/mol, and modified PEI(5 k) with maltose units (PEI-Mal) were investigated in dependence on the molar N/P ratio by using dynamic light scattering (DLS), zeta potential measurements, micro differential scanning calorimetry (mu-DSC), scanning-transmission electron microscopy (STEM), and cryo-scanning electron microscopy (cryo-SEM). A reloading of the polyplexes can be observed by adding the unmodified PEI samples of different molar mass. In excess of PEI a morphological transition from core-shell particles (at N/P 8) to loosely packed onion-like polyplexes (at N/P 40) is observed. The shift of the DSC melting peak from 88 degrees C to 76 degrees C indicates a destabilization of the DNA double helix due to the complexation with the unmodified PEI. Experiments with the maltose-modified PEI show a reloading already at a lower N/P ratio. Due to the presence of the sugar units in the periphery of the polycation electrostatic interactions between DNA become weaker, but cooperative H-bonding forces are reinforced. The resulting less-toxic, more compact polyplexes in excess of the PEI-Mal with two melting points and well distributed DNA segments are of special interest for extended gene delivery experiments. (C) 2015 Elsevier B.V. All rights reserved.
KW  - DNA complexation
KW  - Polyplexes
KW  - Maltose-modified poly(ethyleneimine)
KW  - Morphology
Y1  - 2016
U6  - https://doi.org/10.1016/j.colsurfb.2015.11.061
SN  - 0927-7765
SN  - 1873-4367
VL  - 138
SP  - 78
EP  - 85
PB  - Elsevier
CY  - Amsterdam
ER  -