Fig. 6

The in vitro effect of MTX-loaded MNPs and NIR irradiation. a Gating strategy (left upper) and representative dot plot images (left lower) and a graph (right) on induction of apoptotic death by each treatment in RA-FLS. RA-FLS cells were incubated with various treatments for 72 h and then analyzed by flow cytometry. PBS, PBS-treated FLS; 0.13 μM, MTX solution of 0.13 μM; 30 μM, MTX solution of 30 μM; pMNPs, MTX-unloaded MNPs; mMNPs, MTX-loaded MNPs; NIR, NIR irradiation. b Cell viability versus temperature during NIR irradiation for RA-FLS cells treated with MNPs. *P < 0.05, **P < 0.01, ***P < 0.001 vs. the control group. Values are expressed as mean ± SEM of each experiment. The experiments were conducted in duplicate