TY  - JOUR
A1  - Diehl, Christina
A1  - Cernoch, Peter
A1  - Zenke, Ingrid
A1  - Runge, Heike
A1  - Pitschke, Rona
A1  - Hartmann, Juergen
A1  - Tiersch, Brigitte
A1  - Schlaad, Helmut
T1  - Mechanistic study of the phase separation/crystallization process of poly(2-isopropyl-2-oxazoline) in hot water
N2  - The kinetics of the crystallization of thermoresponsive poly(2-isopropyl-2-oxazoline) in water and the time- dependent evolution of the morphology were examined using wide-angle X-ray scattering and conventional and cryogenic scanning electron microscopy. Results indicate that a temperature-induced phase separation produces a bicontinuous polymer network-like structure, which with the onset of crystallization collapses into individual particles (1-2 mu m in diameter) composed of a porous fiber mesh. Nanofibers then preferentially form at the particle surface, thus wrapping the microspheres like a ball of wool. The particle morphology is severely affected by changes in temperature and less by the initial polymer concentration.
Y1  - 2010
UR  - http://www.rsc.org/Publishing/Journals/sm/index.asp
U6  - https://doi.org/10.1039/C0sm00114g
SN  - 1744-683X
ER  - 
TY  - JOUR
A1  - Shkilnyy, Andriy
A1  - Gräf, Ralph
A1  - Hiebl, Bernhard
A1  - Neffe, Axel T.
A1  - Friedrich, Alwin
A1  - Hartmann, Juergen
A1  - Taubert, Andreas
T1  - Unprecedented, low cytotoxicity of spongelike calcium phosphate/poly(ethylene imine) hydrogel composites
N2  - Covalently crosslinked PEI hydrogels are efficient templates for calcium phosphate mineralization in SBF. In contrast to the PEI hydrogels, non-crosslinked PEI does not lead to calcium phosphate nucleation and growth in SBF. The precipitate is a mixture of brushite and hydroxyapatite. The PEI/calcium phosphate composite material exhibits a sponge like morphology and a chemical composition that is interesting for implants. Cytotoxicity tests using Dictyostelium discoideum amoebae show that both the non-mineralized and mineralized hydrogels have a very low cytotoxicity. This suggests that next generation PEI hydrogels, where also the degradation products are non-toxic, could be interesting for biomedical applications.
Y1  - 2009
UR  - http://www3.interscience.wiley.com/cgi-bin/jhome/77002860
U6  - https://doi.org/10.1002/mabi.200800266
SN  - 1616-5187
ER  -