Topography-Induced Changes in Morphology and Spreading of Human Preadipocytes on Nano- and Micropatterned Polydimethylsiloxane Substrates

The effects of nano- and microtopography on the behavior of human preadipocytes were studied on polydimethylsiloxane (PDMS) patterned substrates. Double-layer substrates composed of high and low elastic modulus PDMS (“hard” and “soft” PDMS) were fabricated by replica molding technique using porous alumina and silicon templates. Three types of surface patterns—ordered nanopillars, disordered micropillars and highly ordered microscale pyramids—as well as non-patterned substrates were used to analyze and compare cell responses. The results showed that the influence of substrate topography on cells behavior strongly depends on the type of the pattern. Preadipocytes grown on the non-patterned PDMS surfaces exhibited flat and fibroblast-like morphology, whereas cells cultured on the patterned substrates progressively elongated and became less flat as the size of the surface features increased. Preadipocytes on the nanopillar surface spread out faster, had more developed lamellipodia and more flattened morphology than on the microsized features. On PDMS micropillars and micropyramids cell spreading was more limited and the cells showed elongated, spindle-shaped morphology. Although the cells were distributed uniformly on each type of substrate, no preferential orientation of cells on the surface was observed. Our work demonstrates that human preadipocytes behavior on patterned substrates is different from their behavior on planar substrates and that the morphology and spreading of these cells can be modulated by varying the structural dimensions of the surface pattern.