TY  - JOUR
A1  - Raju, Rajarshi Roy
A1  - Liebig, Ferenc
A1  - Klemke, Bastian
A1  - Koetz, Joachim
T1  - pH-responsive magnetic Pickering Janus emulsions
JF  - Colloid and polymer science : official journal of the Kolloid-Gesellschaft
N2  - We report ultrasonically generated pH-responsive Pickering Janus emulsions of olive oil and silicone oil with controllable droplet size and engulfment. Chitosan was used as a pH-responsive emulsifier. The increase of pH from 2 to 6 leads to a transition from completely engulfed double emulsion droplets to dumbbell-shaped Janus droplets accompanied by a significant decrease of droplet diameter and a more homogeneous size distribution. The results can be elucidated by the conformational change of chitosan from a more extended form at pH 2 to a more flexible form at pH 4-5. Magnetic responsiveness to the emulsion was attributed by dispersing superparamagnetic nanoparticles (Fe3O4 with diameter of 13 +/- 2 nm) in the olive oil phase before preparing the Janus emulsion. Incorporation of magnetic nanoparticles leads to superior emulsion stability, drastically reduced droplet diameters, and opened the way to control movement and orientation of the Janus droplets according to an external magnetic field.
KW  - Janus emulsion
KW  - Chitosan
KW  - pH-responsive
KW  - Magnetic-responsive
KW  - Cryo-SEM
KW  - TEM
Y1  - 2018
U6  - https://doi.org/10.1007/s00396-018-4321-z
SN  - 0303-402X
SN  - 1435-1536
VL  - 296
IS  - 6
SP  - 1039
EP  - 1046
PB  - Springer
CY  - New York
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  -