@article{LiuGouldRudolphetal.2020,
  author    = {Liu, Yue and Gould, Oliver E. C. and Rudolph, Tobias and Fang, Liang and Kratz, Karl and Lendlein, Andreas},
  title     = {Polymeric microcuboids programmable for temperature-memory},
  series = {Macromolecular materials and engineering},
  volume    = {305},
  journal   = {Macromolecular materials and engineering},
  number    = {10},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1438-7492},
  doi       = {10.1002/mame.202000333},
  pages     = {7},
  year      = {2020},
  abstract  = {Microobjects with programmable mechanical functionality are highly desirable for the creation of flexible electronics, sensors, and microfluidic systems, where fabrication/programming and quantification methods are required to fully control and implement dynamic physical behavior. Here, programmable microcuboids with defined geometries are prepared by a template-based method from crosslinked poly[ethylene-co-(vinyl acetate)] elastomers. These microobjects could be programmed to exhibit a temperature-memory effect or a shape-memory polymer actuation capability. Switching temperaturesT(sw)during shape recovery of 55 +/- 2, 68 +/- 2, 80 +/- 2, and 86 +/- 2 degrees C are achieved by tuning programming temperatures to 55, 70, 85, and 100 degrees C, respectively. Actuation is achieved with a reversible strain of 2.9 +/- 0.2\% to 6.7 +/- 0.1\%, whereby greater compression ratios and higher separation temperatures induce a more pronounced actuation. Micro-geometry change is quantified using optical microscopy and atomic force microscopy. The realization and quantification of microparticles, capable of a tunable temperature responsive shape-change or reversible actuation, represent a key development in the creation of soft microscale devices for drug delivery or microrobotics.},
  language  = {en}
}
@article{TetaliJankowskiLuetzowetal.2016,
  author    = {Tetali, Sarada D. and Jankowski, Vera and Luetzow, Karola and Kratz, Karl and Lendlein, Andreas and Jankowski, Joachim},
  title     = {Adsorption capacity of poly(ether imide) microparticles to uremic toxins},
  series = {Clinical hemorheology and microcirculation : blood flow and vessels},
  volume    = {61},
  journal   = {Clinical hemorheology and microcirculation : blood flow and vessels},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {1386-0291},
  doi       = {10.3233/CH-152026},
  pages     = {657 -- 665},
  year      = {2016},
  abstract  = {Uremia is a phenomenon caused by retention of uremic toxins in the plasma due to functional impairment of kidneys in the elimination of urinary waste products. Uremia is presently treated by dialysis techniques like hemofiltration, dialysis or hemodiafiltration. However, these techniques in use are more favorable towards removing hydrophilic than hydrophobic uremic toxins. Hydrophobic uremic toxins, such as hydroxy hipuric acid (OH-HPA), phenylacetic acid (PAA), indoxyl sulfate (IDS) and p-cresylsulfate (pCRS), contribute substantially to the progression of chronic kidney disease (CKD) and cardiovascular disease. Therefore, objective of the present study is to test adsorption capacity of highly porous microparticles prepared from poly(ether imide) (PEI) as an alternative technique for the removal of uremic toxins. Two types of nanoporous, spherically shaped microparticles were prepared from PEI by a spraying/coagulation process. PEI particles were packed into a preparative HPLC column to which a mixture of the four types of uremic toxins was injected and eluted with ethanol. Eluted toxins were quantified by analytical HPLC. PEI particles were able to adsorb all four toxins, with the highest affinity for PAA and pCR. IDS and OH-HPA showed a partially non-reversible binding. In summary, PEI particles are interesting candidates to be explored for future application in CKD.},
  language  = {en}
}
@article{ZhangSauterFangetal.2015,
  author    = {Zhang, Quanchao and Sauter, Tilman and Fang, Liang and Kratz, Karl and Lendlein, Andreas},
  title     = {Shape-Memory Capability of Copolyetheresterurethane Microparticles Prepared via Electrospraying},
  series = {Macromolecular materials and engineering},
  volume    = {300},
  journal   = {Macromolecular materials and engineering},
  number    = {5},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {1438-7492},
  doi       = {10.1002/mame.201400267},
  pages     = {522 -- 530},
  year      = {2015},
  abstract  = {Multifunctional thermo-responsive and degradable microparticles exhibiting a shapememory effect (SME) have attracted widespread interest in biomedicine as switchable delivery vehicles or microactuators. In this work almost spherical solid microparticles with an average diameter of 3.9 +/- 0.9 mm are prepared via electrospraying of a copolyetheresterurethane named PDC, which is composed of crystallizable oligo(p-dioxanone) (OPDO) hard and oligo(e-caprolactone) (OCL) switching segments. The PDC microparticles are programmed via compression at different pressures and their shapememory capability is explored by off-line and online heating experiments. When a low programming pressure of 0.2 MPa is applied a pronounced thermally-induced shape-memory effect is achieved with a shape recovery ratio about 80\%, while a high programming pressure of 100 MPa resulted in a weak shape-memory performance. Finally, it is demonstrated that an array of PDC microparticles deposited on a polypropylene (PP) substrate can be successfully programmed into a smart temporary film, which disintegrates upon heating to 60 degrees C.},
  language  = {en}
}