Figure 4

Z-stack lifetime distribution of PtL^sCl in melanoma MCTS using one-photon PLIM. (A) representation of a MCTS area (red) imaged using one-photon PLIM across ~100 µm. (B) Lifetime distribution at different depth (z-stack, Scale bar 200 µm) of MCTS. (C) Lifetime values within three different regions (outer, middle, and inner) of MCTS were measured (15 lifetime values, from each data set taken at different depths). Average lifetime values are used to plot lifetime differences within regions of spheroid. Lifetime of central necrotic core becomes shorter towards the periphery of the spheroid. Results shown are mean ± SD (n = 5) (**) denotes statistically significant different when outer (proliferative area) was compared with inner necrotic area. (D) Lifetime distribution histogram of spheroid with PtL^sCl.