@article{SauterLuetzowSchossigetal.2012, author = {Sauter, Tilman and L{\"u}tzow, Karola and Schossig, Michael and Kosmella, Hans and Weigel, Thomas and Kratz, Karl and Lendlein, Andreas}, title = {Shape-memory properties of polyetherurethane foams prepared by thermally induced phase separation}, series = {Advanced engineering materials}, volume = {14}, journal = {Advanced engineering materials}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1438-1656}, doi = {10.1002/adem.201200127}, pages = {818 -- 824}, year = {2012}, abstract = {In this study, we report the preparation of two structurally different shape-memory polymer foams by thermally induced phase separation (TIPS) from amorphous polyetherurethanes. Foams with either a homogeneous, monomodal, or with a hierarchically structured, bimodal, pore size distribution are obtained by adoption of the cooling protocol. The shape-memory properties have been investigated for both foam structures by cyclic, thermomechanical experiments, while the morphological changes on the micro scale (pore level) have been compared to the macro scale by an in situ micro compression device experiment. The results show that the hierarchically structured foam achieves higher shape-recovery rates and a higher total recovery as compared to the homogeneous foam, which is due to an increased energy storage capability by micro scale bending of the hierarchically structured foam compared to pure compression of the homogeneous foam.}, language = {en} } @inproceedings{SauterLuetzowSchossigetal.2013, author = {Sauter, Tilman and L{\"u}tzow, Karola and Schossig, Michael and Kosmella, Hans and Weigel, Thomas and Kratz, Karl and Lendlein, Andreas}, title = {Pore morphology as structural parameter to tailor the shape-memory effect of polyuetherurethane foams}, series = {Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS}, volume = {245}, booktitle = {Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS}, publisher = {American Chemical Society}, address = {Washington}, issn = {0065-7727}, pages = {1}, year = {2013}, language = {en} } @article{HeilmannGrothSchossigetal.2007, author = {Heilmann, Katja and Groth, Thomas and Schossig, Michael and Lendlein, Andreas and Micheel, Burkhard}, title = {Modulation of hybridoma cell growth and antibody production by coating cell culture material with extracellular matrix proteins}, issn = {1369-703X}, doi = {10.1016/j.bej.2007.01.035}, year = {2007}, abstract = {The influence of coating polystyrene tissue culture plates with different proteins on murine hybridoma cell growth and antibody production was investigated. Fibronectin, collagen I, bovine serum albumin and laminin were used to coat NUNC and COSTAR cell culture plates. Cell number and antibody concentration in culture fluids were quantified as indicators for cell viability, proliferation and productivity. Adhesive behaviour, morphology, expression of surface receptors of hybridoma cells and the presence of tyrosine-phosphorylated proteins in cell lysates were characterized by cell adhesion experiments, microscopy, flow cytometry and Western Blot analysis. It was shown that coatings with fibronectin (0.2 ;g/ml) lead to a substantial improvement of cell growth by 50-70\% and an increase of monoclonal antibody production by 100-120\%. Collagen I coatings showed an improvement in cell growth by 30-70\% and by 60\% for the production of monoclonal antibodies. Coatings with BSA and laminin had minor effects on these parameters. It was found that the hybridoma cell lines used in this study did not express the ;2-chain of the ;2;1-integrin, which is responsible for binding to collagen and laminin. However, the presence of ;1- integrin on the cell surface was shown, which should enable hybridoma cells to bind fibronectin. We propose, therefore, that fibronectin adsorption to cell culture materials may be a promising approach to enhance the production of monoclonal antibodies by cultivated hybridoma cells.}, language = {en} } @article{FangGouldLysyakovaetal.2018, author = {Fang, Liang and Gould, Oliver E. C. and Lysyakova, Liudmila and Jiang, Yi and Sauter, Tilman and Frank, Oliver and Becker, Tino and Schossig, Michael and Kratz, Karl and Lendlein, Andreas}, title = {Implementing and quantifying the shape-memory effect of single polymeric micro/nanowires with an atomic force microscope}, series = {ChemPhysChem : a European journal of chemical physics and physical chemistry}, volume = {19}, journal = {ChemPhysChem : a European journal of chemical physics and physical chemistry}, number = {16}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1439-4235}, doi = {10.1002/cphc.201701362}, pages = {2078 -- 2084}, year = {2018}, abstract = {The implementation of shape-memory effects (SME) in polymeric micro- or nano-objects currently relies on the application of indirect macroscopic manipulation techniques, for example, stretchable molds or phantoms, to ensembles of small objects. Here, we introduce a method capable of the controlled manipulation and SME quantification of individual micro- and nano-objects in analogy to macroscopic thermomechanical test procedures. An atomic force microscope was utilized to address individual electro-spun poly(ether urethane) (PEU) micro- or nanowires freely suspended between two micropillars on a micro-structured silicon substrate. In this way, programming strains of 10 +/- 1\% or 21 +/- 1\% were realized, which could be successfully fixed. An almost complete restoration of the original free-suspended shape during heating confirmed the excellent shape-memory performance of the PEU wires. Apparent recovery stresses of sigma(max,app)=1.2 +/- 0.1 and 33.3 +/- 0.1MPa were obtained for a single microwire and nanowire, respectively. The universal AFM test platform described here enables the implementation and quantification of a thermomechanically induced function for individual polymeric micro- and nanosystems.}, language = {en} }