@article{McMasterHoefnerHrynevichetal.2019,
  author    = {McMaster, Rebecca and Hoefner, Christiane and Hrynevich, Andrei and Blum, Carina and Wiesner, Miriam and Wittmann, Katharina and Dargaville, Tim R. and Bauer-Kreisel, Petra and Groll, J{\"u}rgen and Dalton, Paul D. and Blunk, Torsten},
  title     = {Tailored Melt Electrowritten Scaffolds for the Generation of Sheet-Like Tissue Constructs from Multicellular Spheroids},
  series = {Advanced Healthcare Materials},
  volume    = {8},
  journal   = {Advanced Healthcare Materials},
  doi       = {10.1002/adhm.201801326},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223921},
  year      = {2019},
  abstract  = {Melt electrowriting (MEW) is an additive manufacturing technology that is recently used to fabricate voluminous scaffolds for biomedical applications. In this study, MEW is adapted for the seeding of multicellular spheroids, which permits the easy handling as a single sheet-like tissue-scaffold construct. Spheroids are made from adipose-derived stromal cells (ASCs). Poly(ε-caprolactone) is processed via MEW into scaffolds with box-structured pores, readily tailorable to spheroid size, using 13-15 µm diameter fibers. Two 7-8 µm diameter "catching fibers" near the bottom of the scaffold are threaded through each pore (360 and 380 µm) to prevent loss of spheroids during seeding. Cell viability remains high during the two week culture period, while the differentiation of ASCs into the adipogenic lineage is induced. Subsequent sectioning and staining of the spheroid-scaffold construct can be readily performed and accumulated lipid droplets are observed, while upregulation of molecular markers associated with successful differentiation is demonstrated. Tailoring MEW scaffolds with pores allows the simultaneous seeding of high numbers of spheroids at a time into a construct that can be handled in culture and may be readily transferred to other sites for use as implants or tissue models.},
  language  = {en}
}
@article{McCollGrollJungstetal.2018,
  author    = {McColl, Erin and Groll, J{\"u}rgen and Jungst, Tomasz and Dalton, Paul D.},
  title     = {Design and fabrication of melt electrowritten tubes using intuitive software},
  series = {Materials and Design},
  volume    = {155},
  journal   = {Materials and Design},
  doi       = {10.1016/j.matdes.2018.05.036},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223891},
  pages     = {46-58},
  year      = {2018},
  abstract  = {This study approaches the accurate continuous direct-writing onto a cylindrical collector from a mathematical perspective, taking into account the winding angle, cylinder diameter and length required for the final 3D printed tube. Using an additive manufacturing process termed melt electrowriting (MEW), porous tubes intended for tissue engineering applications are fabricated from medical-grade poly(ε-caprolactone) (PCL), validating the mathematically-derived method. For the fabricated tubes in this study, the pore size, winding angle and printed length can all be planned in advance and manufactured as designed. The physical dimensions of the tubes matched theoretical predictions and mechanical testing performed demonstrated that variations in the tubular morphology have a direct impact on their strength. MEWTubes, the web-based application developed and described here, is a particularly useful tool for planning the complex continuous direct writing path required for MEW onto a rotating, cylindrical build surface.},
  language  = {en}
}
@article{HochleitnerJuengstBrownetal.2015,
  author    = {Hochleitner, Gernot and J{\"u}ngst, Tomasz and Brown, Toby D and Hahn, Kathrin and Moseke, Claus and Jakob, Franz and Dalton, Paul D and Groll, J{\"u}rgen},
  title     = {Additive manufacturing of scaffolds with sub-micron filaments via melt electrospinning writing},
  series = {Biofabrication},
  volume    = {7},
  journal   = {Biofabrication},
  number    = {3},
  doi       = {10.1088/1758-5090/7/3/035002},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-254053},
  year      = {2015},
  abstract  = {The aim of this study was to explore the lower resolution limits of an electrohydrodynamic process combined with direct writing technology of polymer melts. Termed melt electrospinning writing, filaments are deposited layer-by-layer to produce discrete three-dimensional scaffolds for in vitro research. Through optimization of the parameters (flow rate, spinneret diameter, voltage, collector distance) for poly-ϵ-caprolactone, we could direct-write coherent scaffolds with ultrafine filaments, the smallest being 817 ± 165 nm. These low diameter filaments were deposited to form box-structures with a periodicity of 100.6 ± 5.1 μm and a height of 80 μm (50 stacked filaments; 100 overlap at intersections). We also observed oriented crystalline regions within such ultrafine filaments after annealing at 55 °C. The scaffolds were printed upon NCO-sP(EO-stat-PO)-coated glass slide surfaces and withstood frequent liquid exchanges with negligible scaffold detachment for at least 10 days in vitro.},
  language  = {en}
}