Fig. 4

Fluorescence visualization of apoptosis in human periosteal cells treated with silica microparticles. The cells were treated with silica microparticles derived from Neotubes for 24 h. The fixed cells were probed with PE-conjugated annexin V for detection of phosphatidylserine on the cell surface, which is accepted as a marker of apoptosis, and are shown at a low magnification and b high magnification. The cells were counterstained with FITC-conjugated phalloidin to visualize cytoskeletal polymerized actin. Similar observations were obtained from four other independent experiments, including those involving Vacuette’s silica. Reprinted with permission from Masuki et al. 2020 [12]