ISBN 978-3-8439-5013-8

978-3-8439-5013-8, Reihe Physikalische Chemie

Stephanie Pieroth
Elastic Polymer Matrices with Tailored Mechanical Properties for Stem Cell Culture and Tissue Engineering

223 Seiten, Dissertation Universität Köln (2021), Softcover, A5

Zusammenfassung / Abstract

The subject of this thesis is the preparation, characterization, and application of synthetic and biobased hydrogels with tunable mechanical properties in the biomedical field. Special focus is laid on the possibility of an upscaling of cell numbers as well as the potential structuring of the designed materials in three-dimensional tissue. For this purpose, polyacrylamide (PAAm) and derivatives besides modified, biobased alginic acid polymers in varying shapes are employed. PAAm hydrogels with varying crosslinking densities are prepared via free radical polymerization in order to obtain materials with tunable mechanical and swelling properties. A controlled adjustment of the mentioned parameters has a direct impact on the suitability of the substrates in cell contact, as cells sense matrix elasticity and show reactions upon it. The polymer networks are biofunctionalized with extracellular matrix (ECM) proteins. In this way, a preferable attachment of cells to the hydrogel surface is enhanced. For realizing an upscaled cell culture, an evaluated flow-focusing microfluidic system is applied to synthesize PAAm hydrogel beads. The obtained beads are for further application in automatized tidal bioreactors. The biofunctionalized materials are then applied in cell culture with human induced pluripotent stem cells (hiPS) and other cell types to investigate the suitability of the substrates. For the realization of a semi three-dimensional cell culture substrate with a high internal surface area, biofunctionalizable PAAm cryogels with characteristic macropores are synthesized. Aiming for the possibility of cell encapsulation and three-dimensional cultivation, responsive materials such as thermoresponsive poly-N-isopropylacrylamide (PNIPAAm) as well as physically crosslinkable and methacrylate group functionalized alginic acid polymers are prepared in spherical shape. The present thesis aims for the contribution to the manufacturing of artificial tissue and organoids.