@article{BorovaTokarevStahlhutetal.2020,
  author    = {Borova, Solomiia and Tokarev, Victor and Stahlhut, Philipp and Luxenhofer, Robert},
  title     = {Crosslinking of hydrophilic polymers using polyperoxides},
  series = {Colloid and Polymer Science},
  volume    = {298},
  journal   = {Colloid and Polymer Science},
  doi       = {10.1007/s00396-020-04738-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238109},
  pages     = {1699-1713},
  year      = {2020},
  abstract  = {Hydrogels that can mimic mechanical properties and functions of biological tissue have attracted great interest in tissue engineering and biofabrication. In these fields, new materials and approaches to prepare hydrogels without using toxic starting materials or materials that decompose into toxic compounds remain to be sought after. Here, we report the crosslinking of commercial, unfunctionalized hydrophilic poly(2-ethyl-2-oxazoline) using peroxide copolymers in their melt. The influence of temperature, peroxide copolymer concentration, and duration of the crosslinking process has been investigated. The method allows to create hydrogels from unfunctionalized polymers in their melt and to control the mechanical properties of the resulting materials. The design of hydrogels with a suitable mechanical performance is of crucial importance in many existing and potential applications of soft materials, including medical applications.},
  language  = {en}
}
@article{HaiderAhmadYangetal.2021,
  author    = {Haider, Malik Salman and Ahmad, Taufiq and Yang, Mengshi and Hu, Chen and Hahn, Lukas and Stahlhut, Philipp and Groll, J{\"u}rgen and Luxenhofer, Robert},
  title     = {Tuning the thermogelation and rheology of poly(2-oxazoline)/poly(2-oxazine)s based thermosensitive hydrogels for 3D bioprinting},
  series = {Gels},
  volume    = {7},
  journal   = {Gels},
  number    = {3},
  issn      = {2310-2861},
  doi       = {10.3390/gels7030078},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241781},
  year      = {2021},
  abstract  = {As one kind of "smart" material, thermogelling polymers find applications in biofabrication, drug delivery and regenerative medicine. In this work, we report a thermosensitive poly(2-oxazoline)/poly(2-oxazine) based diblock copolymer comprising thermosensitive/moderately hydrophobic poly(2-N-propyl-2-oxazine) (pPrOzi) and thermosensitive/moderately hydrophilic poly(2-ethyl-2-oxazoline) (pEtOx). Hydrogels were only formed when block length exceeded certain length (≈100 repeat units). The tube inversion and rheological tests showed that the material has then a reversible sol-gel transition above 25 wt.\% concentration. Rheological tests further revealed a gel strength around 3 kPa, high shear thinning property and rapid shear recovery after stress, which are highly desirable properties for extrusion based three-dimensional (3D) (bio) printing. Attributed to the rheology profile, well resolved printability and high stackability (with added laponite) was also possible. (Cryo) scanning electron microscopy exhibited a highly porous, interconnected, 3D network. The sol-state at lower temperatures (in ice bath) facilitated the homogeneous distribution of (fluorescently labelled) human adipose derived stem cells (hADSCs) in the hydrogel matrix. Post-printing live/dead assays revealed that the hADSCs encapsulated within the hydrogel remained viable (≈97\%). This thermoreversible and (bio) printable hydrogel demonstrated promising properties for use in tissue engineering applications.},
  language  = {en}
}