TY  - JOUR
A1  - Sauter, Tilman
A1  - Geiger, Brett
A1  - Kratz, Karl
A1  - Lendlein, Andreas
T1  - Encasement of metallic cardiovascular stents with endothelial cell-selective copolyetheresterurethane microfibers
JF  - Polymers for advanced technologies
N2  - Cardiovascular metallic stents established in clinical application are typically coated by a thin polymeric layer on the stent struts to improve hemocompatibility, whereby often a drug is added to the coating to inhibit neointimal hyperplasia. Besides such thin film coatings recently nano/microfiber coated stents are investigated, whereby the fibrous coating was applied circumferential on stents. Here, we explored whether a thin fibrous encasement of metallic stents with preferentially longitudinal aligned fibers and different local fiber densities can be achieved by electrospinning. An elastic degradable copolyetheresterurethane, which is reported to selectively enhance the adhesion of endothelial cells, while simultaneously rejecting smooth muscle cells, was utilized for stent coating. The fibrous stent encasements were microscopically assessed regarding their single fiber diameters, fiber covered area and fiber alignment at three characteristic stent regions before and after stent expansion. Stent coatings with thicknesses in the range from 30 to 50 mu m were achieved via electrospinning with 1,1,1,3,3,3-hexafluoro-2-propanol (HFP)-based polymer solution, while a mixture of HFP and formic acid as solvent resulted in encasements with a thickness below 5 mu m comprising submicron sized single fibers. All polymeric encasements were mechanically stable during expansion, whereby the fibers deposited on the struts remained their position. The observed changes in fiber density and diameter indicated diverse local deformation mechanisms of the microfibers at the different regions between the struts. Based on these results it can be anticipated that the presented fibrous encasement of stents might be a promising alternative to stents with polymeric strut coatings releasing anti-proliferative drugs. Copyright (c) 2015 John Wiley & Sons, Ltd.
KW  - multifunctional polymers
KW  - stent coatings
KW  - electrospinning
KW  - biomaterials
KW  - degradable polymers
Y1  - 2015
U6  - https://doi.org/10.1002/pat.3583
SN  - 1042-7147
SN  - 1099-1581
VL  - 26
IS  - 10
SP  - 1209
EP  - 1216
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Julich-Gruner, Konstanze K.
A1  - Löwenberg, Candy
A1  - Neffe, Axel T.
A1  - Behl, Marc
A1  - Lendlein, Andreas
T1  - Recent trends in the chemistry of shape-memory polymers
JF  - Macromolecular chemistry and physics
N2  - Shape-memory polymers (SMPs) are stimuli-sensitive materials capable of performing complex movements on demand, which makes them interesting candidates for various applications, for example, in biomedicine or aerospace. This trend article highlights current approaches in the chemistry of SMPs, such as tailored segment chemistry to integrate additional functions and novel synthetic routes toward permanent and temporary netpoints. Multiphase polymer networks and multimaterial systems illustrate that SMPs can be constructed as a modular system of different building blocks and netpoints. Future developments are aiming at multifunctional and multistimuli-sensitive SMPs.
KW  - multifunctional polymers
KW  - networks
KW  - shape-memory polymers
KW  - stimuli-sensitive polymers
KW  - triple-shape effect
Y1  - 2013
U6  - https://doi.org/10.1002/macp.201200607
SN  - 1022-1352
VL  - 214
IS  - 5
SP  - 527
EP  - 536
PB  - Wiley-VCH
CY  - Weinheim
ER  -