Fig. 4

Influence of biomaterial surface topography on the behavior of bacteria and immune cells. A SEM images of antibacterial topographical features of animal skins and corresponding biomimetic nano-structured surface (biomimetic needles, dragonfly wing, gecko skin and biomimetic diamond nanocone surfaces). (i) Proposed bactericidal mechanisms of the nanopillars on the surface of dragonfly wings and cicada wings. Green arrows indicate separation of bacterial membrane structures. Reproduced with permission [114,115,116,117]. Copyright 2018, Royal Society of Chemistry; Copyright 2017, American Chemical Society; Copyright 2015, Royal Society; Copyright 2016, American Vacuum Society. B Corresponding morphological changes of RAW 264.7 cells on different sizes of honeycomb–like TiO2 nanostructures. C ELISA analyses of cytokines secreted by macrophages attached to different TiO2 structures (IL-1β, TNF-α, IL-4, IL-10, BMP-2 and OSM). D Heatmap analysis of differentially expressed genes related to cytoskeleton arrangement, cell adhesion and mechanotransduction. E Schematic illustrating the mechanism by which surface topography affects macrophage polarization. Reproduced with permission [102]. Copyright 2021, American Association for the Advancement of Science