Use of Nano- and Microtopographies for Controlled Cellular Responses
Author
Foldberg Nielsen, Steffan
Term
4. term
Publication year
2009
Pages
83
Abstract
This thesis investigates how nano- and microtopographies on biomaterial surfaces can guide stem cell behavior in vitro. Three substrate types—oxygen plasma–etched polystyrene, honeycomb-patterned polylactic acid (PLA), and pectin-based scaffolds—were fabricated, characterized, and tested. Surface features and composition were analyzed (e.g., AFM, SEM, EDS), and protein adsorption (fibronectin) was assessed as an indicator of cellophilicity. Stem cell responses were evaluated through spreading morphology, proliferation/viability assays, and expression of selected lineage, adhesion, and signaling genes (qPCR), complemented by immunofluorescence. The results showed that all three surfaces affected cellular behavior: plasma-etched polystyrene altered both gene expression and morphology, while honeycomb PLA influenced spreading morphology without detectable changes in the probed genes. Pectin scaffolds required iterative fabrication improvements to remain stable under cell culture conditions before biological testing. These findings support the use of well-defined nano- and microtopographies to steer cellular responses for future tissue engineering applications.
Denne afhandling undersøger, hvordan nano- og mikrotopografier på biomaterialeoverflader kan styre stamcellers adfærd in vitro. Tre typer substrater—oxygenplasma-ætsede polystyrenoverflader, honningkagemønstrede polylaktid (PLA) og pektinbaserede scaffolds—blev fremstillet, karakteriseret og testet. Overfladers topografi og sammensætning blev analyseret (bl.a. AFM, SEM, EDS), og proteinadsorption (fibronectin) blev vurderet som mål for cellofilicitet. Stamcellernes respons blev målt via spredningsmorfologi, proliferations/viabilitetsassays og genekspression for udvalgte linje-, adhæsions- og signaleringsmarkører (qPCR), suppleret af immunofluorescens. Resultaterne viste, at alle tre overflader påvirkede cellernes adfærd: plasma-ætsede polystyrenoverflader ændrede både genekspression og morfologi, mens honeycomb-PLA påvirkede spredningsmorfologien uden påviselige ændringer i de undersøgte gener. Pektinscaffolds krævede gentagne fabrikationsforbedringer for at være stabile under cellekulturbetingelser før biologisk testning. Studiet peger på, at veldefinerede nano- og mikrotopografier kan bruges til målrettet at påvirke cellers respons i fremtidig vævsteknologi.
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