Controlling cell behaviour: the connection between topography and mechanical properties of biomaterials

Hecht, Sören (2026) Controlling cell behaviour: the connection between topography and mechanical properties of biomaterials. PhD thesis, University of Glasgow.

Abstract

Cells respond to their mechanical environment in vivo, which can be separated into the stiffness and topography of the environment. It drives the cell phenotype. The topography within a range of 100 nm is of special interest because it falls within the size range of protein adhesions. Thus, it is replicated in vitro in fabricated biomaterials to study the effect of the mechanical environment. This thesis aims to investigate the response of the preosteoblast cell line MC3T3 as a well-studied standard cell line to its mechanical environment, with a focus on morphological profiling and traction force microscopy. We analyse the phenotype based on the morphology of the cells using the Cell Painting method. The cell response is dependent on the mechanotransduction pathway. Using activators and inhibitors of the mechanotransduction pathway in combination with 100 nm diameter nanopits showed a mechanotransduction response over time, from an initial Ca2+ signalling to a decrease in intracellular tension and adhesion after four days, and ultimately to senescence and commitment to osteogenic differentiation, as indicated by decreased filopodia and lamellipodia formation. The nanopits have a diameter of 100 nm, a depth of 100 nm, and a centre-tocentre spacing of 300 nm in both square and hexagonal arrays, with and without controlled disorder. We analyse 78 different types of nanopits with varying diameters, disorder, and pitch, as well as six gratings with depths of 200 nm and widths ranging from 200 nm to 10 µm, to have an in-depth analysis of the correlation between phenotype and topography parameters. The gratings cause a substantially different cell morphology compared to the nanopits. They need to be smaller than 5 µm to influence cell morphology. The disorder has the strongest correlation with changes in morphology from the studied topography parameters. We aim to combine the nanotopography with the material stiffness of the biomaterial in the analysis and study the effect of varying nanotopographies on cellular traction forces. However, we are unable to study it due to the challenging fabrication of the required hierarchical micropillars with nanopits on top. We successfully created polydimethylsiloxane (PDMS) micropillars with a diameter of 5.93 ± 0.15 µm and a height of 18.61 ± 0.28 µm using a SU-8 master. We measured a traction force of 10 nN, which aligns with the traction forces reported in the literature for smaller diameter pillars with lower spring constants.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Subjects: T Technology > T Technology (General)
• Colleges/Schools: College of Science and Engineering > School of Engineering > Biomedical Engineering
• Supervisor's Name: Gadegaard, Professor Nikolaj
• Date of Award: 2026
• Depositing User: Theses Team
• Unique ID: glathesis:2026-85703
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 23 Jan 2026 09:20
• Last Modified: 25 Jan 2026 09:04
• Thesis DOI: 10.5525/gla.thesis.85703
• URI: https://theses.gla.ac.uk/id/eprint/85703

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