Figure 6

Reactive oxygen species (ROS) were elevated in HNCCs with GNP-facilitated DTBR. Cells were cultured in 6-well plates, irradiated with 8 Gy from the STB or DTB, then processed for flow cytometry 12 h post radiation. (a) Detroit-562, FaDu, and HSC-3 HNCC lines showed a trend towards higher levels of ROS in GNP-labeled cells irradiated with the DTB (these increases were not significant). GNP Panc1 cells demonstrated a reduced level of ROS after DTBR. (b) Representative flow plots of Detroit-562 cells labelled with CellROX Deep Red Reagent (Ex/Em: 644/665) and SYTOX Blue dead cell stain (Ex/Em: 444/480). Results are presented as means of Relative Median fluorescence intensity (MFI) (where relative MFI = net MFI of treated sample/net MFI of untreated sample × 100) ± standard error of the mean, p* < 0.05, p** < 0.01, p*** < 0.001. Significance between groups was tested using a Mann Whitney test (n = 3; ~ 1 × 10⁶ cells per replicate). GNP gold nanoparticles, NoNP no nanoparticles, HNCC head and neck cancer cells, STB(R) standard target beam (radiation), DTB(R) diamond target beam (radiation).