@phdthesis{Nadernezhad2024,
  author    = {Nadernezhad, Ali},
  title     = {Engineering approaches in biofabrication of vascularized structures},
  doi       = {10.25972/OPUS-34589},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-345892},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2024},
  abstract  = {Biofabrication technologies must address numerous parameters and conditions to reconstruct tissue complexity in vitro. A critical challenge is vascularization, especially for large constructs exceeding diffusion limits. This requires the creation of artificial vascular structures, a task demanding the convergence and integration of multiple engineering approaches. This doctoral dissertation aims to achieve two primary objectives: firstly, to implement and refine engineering methods for creating artificial microvascular structures using Melt Electrowriting (MEW)-assisted sacrificial templating, and secondly, to deepen the understanding of the critical factors influencing the printability of bioink formulations in 3D extrusion bioprinting. In the first part of this dissertation, two innovative sacrificial templating techniques using MEW are explored. Utilizing a carbohydrate glass as a fugitive material, a pioneering advancement in the processing of sugars with MEW with a resolution under 100 microns was made. Furthermore, by introducing the "print-and-fuse" strategy as a groundbreaking method, biomimetic branching microchannels embedded in hydrogel matrices were fabricated, which can then be endothelialized to mirror in vivo vascular conditions. The second part of the dissertation explores extrusion bioprinting. By introducing a simple binary bioink formulation, the correlation between physical properties and printability was showcased. In the next step, employing state-of-the-art machine-learning approaches revealed a deeper understanding of the correlations between bioink properties and printability in an extended library of hydrogel formulations. This dissertation offers in-depth insights into two key biofabrication technologies. Future work could merge these into hybrid methods for the fabrication of vascularized constructs, combining MEW's precision with fine-tuned bioink properties in automated extrusion bioprinting.},
  subject      = {3D-Druck},
  language  = {en}
}
@phdthesis{Ryma2022,
  author    = {Ryma, Matthias},
  title     = {Exploiting the Thermoresponsive Properties of Poly(2-oxazoline)s for Biofabrication},
  doi       = {10.25972/OPUS-24746},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-247462},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {In this thesis, non-modified POx, namely PnPrOx and PcycloPrOx, with an LCST in the physiological range between 20 and 37°C have been utilized as materials for three different biofabrication approaches. Their thermoresponsive behavior and processability were exploited to establish an easy-to-apply coating for cell sheet engineering, a novel method to create biomimetic scaffolds based on aligned fibrils via Melt Electrowriting (MEW) and the application of melt electrowritten sacrificial scaffolds for microchannel creation for hydrogels. Chapter 3 describes the establishment of a thermoresponsive coating for tissue culture plates. Here, PnPrOx was simply dissolved in water and dried in well plates and petri dishes in an oven. PnPrOx adsorbed to the surface, and the addition of warm media generated a cell culture compatible coating. It was shown that different cell types were able to attach and proliferate. After confluency, temperature reduction led to the detachment of cell sheets. Compared to standard procedures for surface coating, the thermoresponsive polymer is not bound covalently to the surface and therefore does not require specialized equipment and chemical knowledge. However, it should be noted that the detachment of the cell layer requires the dissolution of the PnPrOx-coating, leading to possible polymer contamination. Although it is only a small amount of polymer dissolved in the media, the detached cell sheets need to be washed by media exchange for further processing if required. ...},
  subject      = {Thermoresponsive Polymere},
  language  = {en}
}