Altering the mechanical anisotropy of the Anisogel to affect cell behaviour
| Autor: | Babu, Susan |
|---|---|
| Přispěvatelé: | De Laporte, Laura, Pich, Andrij |
| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: |
Anisotropie
microfluidics anisotropy Mikrofluidik hydrogels anisotropy magnetic microgels biomechanical properties nerve alignment microfluidics Hydrogele Anisotropie magnetische Mikrogele biomechanische Eigenschaften Nervenausrichtung Mikrofluidik magnetic microgels magnetische Mikrogele ddc:540 Nervenausrichtung Hydrogele biomechanical properties biomechanische Eigenschaften hydrogels nerve alignment |
| Zdroj: | Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen, Diagramme (2023). doi:10.18154/RWTH-2023-05368 = Dissertation, RWTH Aachen University, 2023 |
| DOI: | 10.18154/RWTH-2023-05368 |
| Popis: | Dissertation, RWTH Aachen University, 2023; Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen, Diagramme (2023). = Dissertation, RWTH Aachen University, 2023 The overarching goal of this thesis is to demonstrate how the design of hydrogels for tissue engineering can be fine-tuned to meet the requirements of each cell type or tissue to provide the best conditions for cellular regrowth and organization in three dimensions (3D). A synthetic, injectable and enzymatically crosslinked polyethylene glycol-based (PEG) hydrogel is chosen as a candidate for this purpose because of its cell-friendly cross-linking mechanism under physiological conditions and the ease with which various material parameters can be modified. Firstly, the PEG hydrogel is shown to successfully support the growth of two different types of cell aggregates; embryoid bodies and breast cell spheroids, by the modification of their bulk properties such as stiffness, degradation rate and type and concentration of cell adhesive biomolecules. The breast spheroid culture system in PEG is then used to develop a 3D traction force microscopy setup to quantify cell induced traction forces against its surrounding matrix. Additionally, these hydrogels are used to establish a novel ferrofluid droplet based microrheology platform, which would enable the measurement of local viscoelastic properties of biological samples. For the regeneration of aligned tissues like spinal cord, these hydrogels have to be modified to introduce some directional guidance. This is achieved by the incorporation of oriented rod-shaped magnetic microgels to form an Anisogel. Anisogels are used in this work to guide the growth of neurites from dorsal root ganglia extracted from chick embryos, mice and rats. However, in each of these cases, cell growth is controlled by modifying local rather than bulk hydrogel properties. This is achieved by varying the mechanical and biochemical properties of the microgels, microgel orientation and co-culture with supporting cells. Although PEG-based Anisogel has many advantages, it is inherently elastic and difficult to handle during in vivo injections. Hence, three different kinds of physically crosslinked and viscoelastic hydrogels are tested for their suitability as Anisogel matrices and a Ureido-Pyrimidinone based hydrogel is shown to be successful in supporting aligned nerve growth comparable to PEG-based Anisogels. Lastly, two different techniques for microgel production are demonstrated to introduce a higher degree of complexity in Anisogels. Microgels can thus be pre-programmed to align in any specific direction under a fixed magnetic field to form multi-directional Anisogels and can be continuously produced using microfluidics to enable a smooth clinical translation of Anisogels. Published by RWTH Aachen University, Aachen |
| Databáze: | OpenAIRE |
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