Abstract

Macrophages play a major role in mediating foreign body response to implants.The majority of current effort to alter the foreign body response has focused on modulating biomaterial surface chemistry.We address the hypothesis that micro-and nano-topographical cues，in mimicking native ECM architecture，can influence macrophage behavior in the foreign body response model.Poly（dimethyl siloxane） （PDMS） gratings of line widths between 300 nm to 1 μm were used to characterize the effect of topography on macrophage behavior.Two types of human monocyte/macrophage cell systems，THP-1 and peripheral blood monocyte （PBMC）-derived primary macrophages，were examined over 1 to 7 days.Topography gratings caused decreased THP-1 cell spreading and phagocytic activity compared to planar controls.THP-1 secretion of IL-1ra and MCP-1 decreased on PDMS gratings compared to planar surfaces at Day 1，while the corresponding IL-10 levels increased with larger-sized topography at Day 7.FBGC fusion in primary macrophages was significantly reduced compared to planar counterparts at Day 3，but the trend was reversed at Day 7.In general，primary macrophage cytokine secretion was sensitive to topographic effects on Day 1.This study presents evidence that topography can differentially affect cell adhesion，morphology change，phagocytosis activity，FBGC fusion and cytokine secretion in monocyte/macrophage cells derived from different sources.