TY  - JOUR
A1  - Schulze, Nicole
A1  - Tiersch, B.
A1  - Zenke, I.
A1  - Koetz, Joachim
T1  - Polyampholyte-tuned lyotrop lamellar liquid crystalline systems
JF  - COLLOID AND POLYMER SCIENCE
N2  - The influence of a polyampholyte, i.e., poly(N,N’-diallyl-N,N’-dimethyl-altmaleamic carboxylate) (PalH), on the lamellar liquid crystalline (LC) system sodium dodecyl sulfate (SDS)/decanol/water was investigated by means of microdifferential scanning calorimetry, small-angle X-ray diffraction (SAXS), and cryo-scanning electron microscopy. After incorporating PalH into the lamellar liquid crystalline system, SAXS measurements show that three different LC phases exist: i.e., a swelling, slightly swelling, and non-swelling one. At pH 4, the positively charged polymer with an extended conformation can directly adsorb at the anionic head groups of the surfactant and more compact vesicles are formed at room temperature. At pH 9, the electrostatic interactions between the polyampholyte (in a more coiled conformation) and the sulfate head groups of the SDS are leveled off and incompact vesicles are formed at room temperature. That means in presence of the polyampholyte the morphology of the LC phase, i.e., the supramolecular vesicle structure, can be tuned by varying the pH and/or the temperature.
KW  - Polyampholytes
KW  - Lamellar liquid crystals
KW  - Vesicle formation
KW  - SAXS
KW  - Cryo-SEM
KW  - mu-DSC
Y1  - 2013
U6  - https://doi.org/10.1007/s00396-013-2999-5
SN  - 0303-402X
SN  - 1435-1536
VL  - 291
IS  - 11
SP  - 2551
EP  - 2559
PB  - SPRINGER
CY  - NEW YORK
ER  - 
TY  - JOUR
A1  - Rumschöttel, Jens
A1  - Baus, Susann
A1  - Kosmella, Sabine
A1  - Appelhans, Dietmar
A1  - Koetz, Joachim
T1  - Incorporation of DNA/PEI polyplexes into gelatin/chitosan hydrogel scaffolds
BT  - a mu-DSC study
JF  - Composite interfaces
N2  - Polyplexes between a double-stranded Salmon DNA and hyperbranched poly(ethyleneimine) (PEI) as well as a maltosylated PEI-Mal were incorporated into a gelatin/chitosan hydrogel scaffold. Calorimetric experiments of the polyplexes show a decrease of the melting temperature in presence of PEI and a peak splitting in presence of PEI-Mal, which can be interpreted to a partial compaction of the DNA strands in presence of PEI-Mal. When the polyplexes are incorporated into a gelatin/chitosan scaffold in the swollen state, the DNA melting peaks at 90 and 93 degrees C, respectively, indicate in both cases the release of the DNA at the surface of the hydrogel scaffold in a more compact form. Specific interactions between the PEI-Mal shell and gelatin are responsible for the tuning of the release properties in presence of the maltose units in the hyperbranched PEI.
KW  - DNA-PEI polyplexes
KW  - maltosylated poly(ethyleneimine)
KW  - mu-DSC
KW  - DNA release
KW  - gelatin/chitosan hydrogel scaffold
Y1  - 2017
U6  - https://doi.org/10.1080/09276440.2017.1302725
SN  - 1568-5543
VL  - 25
IS  - 1
SP  - 1
EP  - 11
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Rumschoettel, Jens
A1  - Kosmella, Sabine
A1  - Prietzel, Claudia Christina
A1  - Appelhans, Dietmar
A1  - Koetz, Joachim
T1  - DNA polyplexes with dendritic glycopolymer-entrapped gold nanoparticles
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, composed of Salmon DNA and very small gold nanoparticles embedded into a dendritic glycopolymer architecture of sugar-modified poly(ethyleneimine) (PEI-Mal) with a molar mass of about 25,000 g/mol, were characterized by dynamic light scattering (DLS), zeta potential measurements, micro differential scanning calorimetry (mu-DSC) and transmission electron microscopy (TEM). The PEI-Mal-entrapped gold nanoparticles of about 2 nm in diameter influence the polyplex formation of the hyperbranched PEI containing bulky maltose, and in consequence the DNA is more compactized in the inner part of spherical polyplex particles of about 150 nm in diameter. The resulting more compact core shell polyplex particles with embedded gold nanoparticles in the outer polymer shell will be used as components in forthcoming gene delivery experiments. (C) 2017 Elsevier B.V. All rights reserved.
KW  - DNA polyplexes
KW  - Gold nanoparticles
KW  - Maltose-modified poly(ethyleneimine)
KW  - TEM
KW  - mu-DSC
Y1  - 2017
U6  - https://doi.org/10.1016/j.colsurfb.2017.03.001
SN  - 0927-7765
SN  - 1873-4367
VL  - 154
SP  - 74
EP  - 81
PB  - Elsevier
CY  - Amsterdam
ER  -