Substrate topography as well as changes in the physical microenvironment of cells play a major role in cell adhesion and cytoskeletal changes, thereby influencing intracellular signaling and other cellular properties.1,2 In particular scaffold porosity is known to influence cellular integration into a host tissue, which is especially important for wound healing.3 Therefore, we studied how 3T3 fibroblasts and HaCaT keratinocytes interact with microporous alumina textiles as a potential scaffold material for wound repair.
The ceramic textiles supported the adhesion of keratinocytes and fibroblasts up to 120 h in culture. For HaCaT keratinocytes on microporous alumina textiles a distinct difference in morphology was observed compared to standard tissue culture (TC) plates and anodic aluminium oxide (AAO) nanopores where HaCaTs grew in clusters.4 The unique woven topography of the microporous alumina textiles induced visible cytoskeleton changes which were associated with an elongated cell shape as observed by phalloidin staining. SEM analysis further revealed that HaCaTs had formed multiple contact points along the filaments of the alumina textiles hence inducing changes in the cell morphology and adhesion pattern. Fibroblasts also adhered well to microporous alumina textiles yet with minimal changes in their morphology compared to TC plates and nanoporous AAO membranes.
Inspired by these differences in cell morphology, further analysis of protein expression in keratinocytes on alumina textiles revealed upregulation of fibronectin expression followed by downregulation of E-cadherin. These differences in the expression of cell-specific maker proteins indicate that topography-induced changes in cell adhesion might be related with the epithelial-mesenchymal transition (EMT) of epithelial cells. This porosity-driven induction of EMT of keratinocytes on alumina textiles could potentially promote native wound repair mechanisms.
In summary, our results suggest that microporous alumina textiles, although being an inorganic biomaterial, are very attractive scaffolds for skin tissue engineering.

Keywords: alumina textiles, wound repair, EMT, cell adhesion, topography