Regensburg 2019 – wissenschaftliches Programm
BP 27.1: Vortrag
Donnerstag, 4. April 2019, 15:00–15:15, H10
Cell Adhesion as a Function of Hydrogel Layer Thickness: From Thin Layers to Bulk Samples — •Sandra Sindt, Galen Ream, and Christine Selhuber-Unkel — Institute of Materials Science, CAU Kiel, Germany
Cells are in vivo in contact with a large range of different mechanical environments. However, many tissues have complicated structures without distinct elasticity values, which can result in stiffness gradients close to their interfaces and cells are known to be capable of sensing a more rigid substrate underneath a soft structure. For example, Buxboim et al. have recently shown that mesenchymal stem cells show increased adhesive spreading on thin soft hydrogels due to a stiff underlying substrate. A threshold of rigidity sensing of fibroblasts was reported to be 60-70 micrometer thickness at approximately 1 kPa of elastic modulus. We here report results on the dependency of cell adhesion on hydrogel thickness and elasticity. This is of great importance for the design and development of coatings for various biomedical applications. We use polyacrylamide layers on glass slides with thicknesses below 100 micrometer to semi-infinite bulk samples (ca. 500 micrometer). Furthermore, we use two different elasticities to determine, if the effective cellular substrate sensing depth is affected by the elasticity of the samples. Our results demonstrate that the spreading area and circularity is strongly influenced by the thickness of the polyacrylamide samples. However, there was no conclusive difference in this effect for both stiffnesses.