The Impact of Substrate Topography on Cell Filopodia Extension and Cell Spreading

Recent research has found that cell spreading on materials affects cell functions, including proliferation and differentiation. Also, cell spreading is related to filopodia extension which has been shown to be dependent on substrate topography. To better understand this correlation, live-cell imaging was used here to investigate osteoblast (bone forming cell) filopodia extension and cell spreading on two different kinds of diamond. Nanocrystalline diamond (NCD) and submicron crystalline diamond (SMCD) were fabricated to possess similar surface chemistry but different topographies, consisting of nanoscale spherical grains in NCD and submicron polyhedral grains in SMCD. The filopodia extension and cell expansion results showed that cells on nanoscale topographies had faster filopodia extension and greater expansion area than on submicron topographies. Results indicated that substrate topography has an impact on cell filopodia extension and cell spreading, and NCD promoted filopodia extension and cell expansion better than SMCD.