@article{PilusoHieblGorbetal.2011,
  author    = {Piluso, Susanna and Hiebl, Bernhard and Gorb, Stanislav N. and Kovalev, Alexander and Lendlein, Andreas and Neffe, Axel T.},
  title     = {Hyaluronic acid-based hydrogels crosslinked by copper-catalyzed azide-alkyne cycloaddition with tailorable mechanical properties},
  series = {The international journal of artificial organs},
  volume    = {34},
  journal   = {The international journal of artificial organs},
  number    = {2},
  publisher = {Wichtig},
  address   = {Milano},
  issn      = {0391-3988},
  doi       = {10.5301/IJAO.2011.6394},
  pages     = {192 -- 197},
  year      = {2011},
  abstract  = {Biopolymers of the extracellular matrix are attractive starting materials for providing degradable and biocompatible biomaterials. In this study, hyaluronic acid-based hydrogels with tunable mechanical properties were prepared by the use of copper-catalyzed azide-alkyne cycloaddition (known as "click chemistry"). Alkyne-functionalized hyaluronic acid was crosslinked with linkers having two terminal azide functionalities, varying crosslinker density as well as the lengths and rigidity of the linker molecules. By variation of the crosslinker density and crosslinker type, hydrogels with elastic moduli in the range of 0.5-4 kPa were prepared. The washed materials contained a maximum of 6.8 mg copper per kg dry weight and the eluate of the gel crosslinked with diazidostilbene did not show toxic effects on L929 cells. The hyaluronic acid-based hydrogels have potential as biomaterials for cell culture or soft tissue regeneration applications.},
  language  = {en}
}
@article{NeffeLoebusZaupaetal.2011,
  author    = {Neffe, Axel T. and Loebus, Axel and Zaupa, Alessandro and St{\"o}tzel, Christian and M{\"u}ller, Frank A. and Lendlein, Andreas},
  title     = {Gelatin functionalization with tyrosine derived moieties to increase the interaction with hydroxyapatite fillers},
  series = {Acta biomaterialia},
  volume    = {7},
  journal   = {Acta biomaterialia},
  number    = {4},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {1742-7061},
  doi       = {10.1016/j.actbio.2010.11.025},
  pages     = {1693 -- 1701},
  year      = {2011},
  abstract  = {Combining gelatins functionalized with the tyrosine-derived groups desaminotyrosine or desaminotyrosyl tyrosine with hydroxyapatite (HAp) led to the formation of composite materials with much lower swelling ratios than those of the pure matrices. Shifts of the infra-red (IR) bands related to the free carboxyl groups could be observed in the presence of HAp, which suggested a direct interaction of matrix and filler that formed additional physical cross-links in the material. In tensile tests and rheological measurements the composites equilibrated in water had increased Young's moduli (from 200 kPa up to 2 MPa) and tensile strengths (from 57 kPa up to 1.1 MPa) compared with the matrix polymers without affecting the elongation at break. Furthermore, an increased thermal stability of the networks from 40 to 85 degrees C could be demonstrated. The differences in the behaviour of the functionalized gelatins compared with pure gelatin as a matrix suggested an additional stabilizing bond between the incorporated aromatic groups and the HAp as supported by the IR results. The composites can potentially be applied as bone fillers.},
  language  = {en}
}