Micropatterning with conical features can control bacterial adhesion on silicone

The surface topography plays a pivotal role in microbial adhesion and biofilm formation. Silicone with surfaces presenting cones, a new type of geometrical feature in surface patterning, was prepared using laser ablation. These cones had narrowly distributed diameters ranging from 20 to 40 mm with distances of 4, 8 and 13 mm. The samples were placed in suspensions of Escherichia coli or Staphylococcus epidermidis and bacteria were allowed to adhere for 5 hours; the attached cells were analyzed with Live/Dead staining. The results revealed that the distance between features did not have a significant effect; cones with diameters of 25 and 30 mm enhanced the number of both microorganism species on the surface compared to cones of 20 and 40 mm. Bacterial cells were predominantly identified on the valleys around features and not on their tops. Unpatterned samples showed a random distribution of biofilm on the surface. Our results demonstrate that it is possible to favor or hinder bacterial adhesion on silicone through micropatterning.