@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}
}
@phdthesis{Hauptstein2022,
  author    = {Hauptstein, Julia},
  title     = {Hyaluronic Acid-based Multifunctional Bioinks for 3D Bioprinting of Mesenchymal Stromal Cells for Cartilage Regeneration},
  doi       = {10.25972/OPUS-26068},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260681},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Articular cartilage is a highly specialized tissue which provides a lubricated gliding surface in joints and thereby enables low-friction movement. If damaged once it has a very low intrinsic healing capacity and there is still no treatment in the clinic which can restore healthy cartilage tissue. 3D biofabrication presents a promising perspective in the field by combining healthy cells and bioactive ink materials. Thereby, the composition of the applied bioink is crucial for defect restoration, as it needs to have the physical properties for the fabrication process and also suitable chemical cues to provide a supportive environment for embedded cells. In the last years, ink compositions with high polymer contents and crosslink densities were frequently used to provide 3D printability and construct stability. But these dense polymeric networks were often associated with restricted bioactivity and impaired cell processes like differentiation and the distribution of newly produced extracellular matrix (ECM), which is especially important in the field of cartilage engineering. Therefore, the aim of this thesis was the development of hyaluronic acid (HA)-based bioinks with a reduced polymer content which are 3D printable and additionally facilitate chondrogenic differentiation of mesenchymal stromal cells (MSCs) and the homogeneous distribution of newly produced ECM. Starting from not-printable hydrogels with high polymer contents and restricted bioactivity, distinct stepwise improvements were achieved regarding stand-alone 3D printability as well as MSC differentiation and homogeneous ECM distribution. All newly developed inks in this thesis made a valuable contribution in the field of cartilage regeneration and represent promising approaches for potential clinical applications. The underlying mechanisms and established ink design criteria can further be applied to other biofabricated tissues, emphasizing their importance also in a more general research setting.},
  subject      = {Hyalurons{\"a}ure},
  language  = {en}
}
@phdthesis{Kurum2022,
  author    = {Kurum, Tamer},
  title     = {Simulation der Kariesentfernung an 3D-gedruckten Molaren: Analyse der Reliabilit{\"a}t und der Validit{\"a}t},
  doi       = {10.25972/OPUS-26000},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260003},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {In der vorliegenden Studie wurde an 50 3D-gedruckten Molaren mit einer konstruierten Referenzkaries das Ausmaß der vollst{\"a}ndigen Kariesentfernung fl{\"a}chenabh{\"a}ngig {\"u}berpr{\"u}ft. Die untersuchten Z{\"a}hne wurden mit einer simulierten, standardisierten und mehrfl{\"a}chigen Karies versehen. Studierende der Zahnmedizin haben die Karies entfernt, die Kavit{\"a}t mit einer Aufbauf{\"u}llung versorgt und die Z{\"a}hne f{\"u}r eine Vollkrone pr{\"a}pariert. Um die Kariesentfernung zu bewerten, wurden DVT-Aufnahmen und dreidimensionale Scans angefertigt. Aus den DVT-Datens{\"a}tzen im DICOM-Format wurden die Aufbauf{\"u}llungen der Z{\"a}hne mithilfe digitaler Bildverarbeitung segmentiert und als eigenst{\"a}ndige 3D-Modelle dargestellt. Anschließend erfolgte die {\"U}berlagerung der Aufbauf{\"u}llungen auf den Referenzzahn aus der Konstruktionsdatei der Z{\"a}hne. Mit der Konstruktionssoftware Autodesk Fusion 360 wurden die Aufbauf{\"u}llungen in Volumenk{\"o}rper umgewandelt und mit der Karies des Referenzzahnes verglichen. Da sich die Aufbauf{\"u}llungen mit der Referenzkaries {\"u}berschneiden, konnte die Software mit ihrer Teilungsfunktion nicht {\"u}berschneidende Teile separieren. Abh{\"a}ngig von der Lage der Kavit{\"a}t, in der sich die {\"u}bersch{\"u}ssigen Volumenk{\"o}rper befanden, wurden jene als Restkaries oder {\"u}berexkavierte Zahnhartsubstanz identifiziert. Die gemessenen Volumina von Restkaries ergaben, dass an der distalen Zahnfl{\"a}che im Vergleich zur bukkalen und okklusalen signifikant mehr Karies verblieben war. Ein weiterer signifikanter Unterschied konnte zwischen mesial und bukkal, jedoch nicht zwischen mesial und okklusal festgestellt werden. Bei der {\"U}berexkavation gab es zwischen den Zahnfl{\"a}chen keine Unterschiede. Die Ergebnisse zeigten, dass die Kariesentfernung an den approximalen Zahnfl{\"a}chen f{\"u}r die Studierenden eine h{\"o}here manuelle Herausforderung darstellte. Neben der volumetrischen Vermessung erm{\"o}glichte die dreidimensionale Visualisierung von Restkaries und der {\"u}berexkavierten Zahnhartsubstanz eine objektive Bewertung des Behandlungsergebnisses f{\"u}r die Studierenden und deren Ausbilder. Besonders der Vergleich mit einer Referenz schaffte eine valide und nachvollziehbare Beurteilung der Karies{\"u}bung an 3D-gedruckten Z{\"a}hnen.},
  subject      = {Karies},
  language  = {de}
}