Fig. 9

Visualization and quantification of THP-1 cell fusion in monoculture and co-culture systems. Cell fusion occurred in all groups including the control group without particle treatment for THP-1 cells (a). Monocultured (b, c) 100 nm and 500 nm NP-induced significant cell fusion compared to 1 µm PLGA group (d), which has a slightly higher level than that of the control group. In co-cultured systems, 100 nm (g) and 1 µm (e) PLGA had an identical percentage of cellular fusion, which is apparently smaller than that of 500 nm group (f). Quantification of cell fusion for all groups after 24 h incubation was displayed in h