Defence of doctoral thesis in the field of engineering physics, MSc Kia Bertula

Title of the doctoral thesis is "Polymer and gel networks - From self-assembly to structure, properties, and application"

Nature has been a forerunner to create materials with excellent mechanical properties including spider silk, nacre, and animal tissues. These properties are based on a well-defined hierarchical structure that is organized in multiple length scales - from the nanoscale to the macroscale. Material technology is trying to mimic and prepare synthetic materials with similar properties using so-called self-assembly, in which pre-existing smaller molecules and components spontaneously organize into larger structures. Challenge has been to control and guide self-assembly processes between the molecules and particles. In addition, there are still more material properties, such as strain-stiffening, that are not well understood.

This dissertation focuses on three different targets: 1) develop new tools to control molecules’ self-assembly to network structures, 2) investigate specific mechanical property: strain-stiffening, of agarose hydrogels, and 3) study various hydrogels as 3D-matrixes for the breast cancer explant culturing. The objective was to get a new insight into material properties and find new ways to guide self-assembly processes - which can help to develop new materials.

The first part of the results presents new tools to control the self-assembly of small molecules to larger network structures. Chemical interactions between the molecules were controlled with solvent, UV-light, and temperature to guide the self-assembly into hierarchical structures and functional hydrogels.

The second part shows that agarose hydrogels are strain-stiffening materials. Behavior was analyzed and the mechanism for the origin of the strain-stiffening was suggested. Results can help to develop synthetic strain-stiffening materials, especially for biomedical applications.

The last part presents that the chemical composition and stiffness of the hydrogels used as 3D-matrix regulates the growth and differentiation of breast cancer cells. These findings can provide 3D-culturing platforms that can help to develop new medicines against breast cancer, as well as personal drug screening.

Opponent is Professor Felix Schacher, Friedrich Schiller University Jena, Germany

Custos is Professor Olli Ikkala, Aalto University School of Science, Department of Applied Physics

Contact details of the doctoral candidate: [email protected], 0408275851

The public defence will be organised on campus and via Zoom. Link to the event

The dissertation is publicly displayed 10 days before the defence in the publication archive Aaltodoc of Aalto University

Electronic thesis

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