Photodynamic activity of thiophene-derived lysosome-specific dyes

• TC dyes interact with HSA as indicated by UV–Vis and fluorescence measurements.
• TC1 and TC2 result in efficient 1O2 generators.
• TC1 and TC2 cause a rapid intracellular ROS release following light beam exposure.
• TC1 compound has a considerable photo-toxic effect in human fibrosarcoma cells.

The photodynamic activity occurring through the lysosome photo-damage is effective in terms of triggered synergic effects which can avoid chemo-resistance pathways. The potential photodynamic activity of two fluorescent lysosome-specific probes was studied providing their interaction with human serum albumin, demonstrating their in vitro generation of singlet oxygen and investigating the resulted photo-toxic effect in human cancer cells.