IADR Abstract Archives
Novel Grooved Substrata Stimulate Macrophage Fusion, CCL2 and MMP-9 Secretion
Objectives: Objectives: To investigate the role of surface topography in regulating macrophage behavior by determining cytokine and matrix metallopeptidase 9 (MMP-9) secretion of RAW264.7 macrophages on novel grooved (G) surfaces fabricated by anisotropic-etching of Si (110) crystals.
Methods: Methods: Anisotropic-etching of Si (110) crystals produced G surfaces (designated as G1) with an average depth of 0.88μm whereas more vigorous condition produced surfaces (designated as G2) with an average roughness value (Ra) of 1.2μm. Murine macrophage-like RAW264.7 cells were cultured on polished (Pol), G1 and G2 surfaces for 1 and 5 days. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to analyze the gene expression and cyto-/chemokine antibody microarray and ELISA were used to quantify cyto-/chemokine and MMP-9 secretion. Multinucleated cell formation was evaluated by confocal microscopy.
Results: Results: Macrophages cultured on G1 and G2 exhibited a cell morphology that was similar to M2 (alternatively activated) macrophage phenotype produced by adding Interleukin-4 to cells on Pol. RAW264.7 cells aligned with the grooves on G1 surfaces. Both RT-qPCR and cytokine microarray results showed statistically significant up-regulation of macrophage chemoattractants (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, CCL5/RANTES, and CCL7/MCP-3) on G1 and G2 relative to polished surfaces. The pattern of cytokine secretion suggested an M2-like phenotype on G1 and G2 surfaces. Secretion of critical participants of macrophage fusion – CCL2/MCP-1 and matrix metallopeptidase 9 (MMP-9) – was increased on G2 and cell fusion was enhanced on G1 and G2, relative to polished surfaces.
Conclusions: Conclusion: Bulk anisotropic etching produced microscale grooved surfaces (G1 and G2) without the need for photolithography. G1 and G2 topographies increased secretion of chemokines involved in recruitment and fusion of macrophages. Substratum surface topography enhanced macrophage fusion and thus may be important in regulating foreign body giant cell (FBGC) formation on implants.
Methods: Methods: Anisotropic-etching of Si (110) crystals produced G surfaces (designated as G1) with an average depth of 0.88μm whereas more vigorous condition produced surfaces (designated as G2) with an average roughness value (Ra) of 1.2μm. Murine macrophage-like RAW264.7 cells were cultured on polished (Pol), G1 and G2 surfaces for 1 and 5 days. Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) was used to analyze the gene expression and cyto-/chemokine antibody microarray and ELISA were used to quantify cyto-/chemokine and MMP-9 secretion. Multinucleated cell formation was evaluated by confocal microscopy.
Results: Results: Macrophages cultured on G1 and G2 exhibited a cell morphology that was similar to M2 (alternatively activated) macrophage phenotype produced by adding Interleukin-4 to cells on Pol. RAW264.7 cells aligned with the grooves on G1 surfaces. Both RT-qPCR and cytokine microarray results showed statistically significant up-regulation of macrophage chemoattractants (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, CCL5/RANTES, and CCL7/MCP-3) on G1 and G2 relative to polished surfaces. The pattern of cytokine secretion suggested an M2-like phenotype on G1 and G2 surfaces. Secretion of critical participants of macrophage fusion – CCL2/MCP-1 and matrix metallopeptidase 9 (MMP-9) – was increased on G2 and cell fusion was enhanced on G1 and G2, relative to polished surfaces.
Conclusions: Conclusion: Bulk anisotropic etching produced microscale grooved surfaces (G1 and G2) without the need for photolithography. G1 and G2 topographies increased secretion of chemokines involved in recruitment and fusion of macrophages. Substratum surface topography enhanced macrophage fusion and thus may be important in regulating foreign body giant cell (FBGC) formation on implants.