Sonodynamically Induced Cell Damage Using Rose Bengal Derivative

Aim: The ultrasonically induced effect of a tumor accumulative derivative of rose bengal (RB) on isolated tumor cells was investigated to clarify whether the RB derivative (RBD) maintains the sonosensitizing ability of RB. Materials and Methods: Sarcoma 180 cells were suspended in air-saturated phosphate-buffered saline and were exposed to ultrasound in standing wave mode for up to 60 s in the presence and absence of RBD or RB. The viability of the cells was determined by the ability to exclude trypan blue. Results: The ultrasonically induced cell-damaging rate with 100 mu M RBD was one order of magnitude higher than that with the same concentration of RB. This increase was significantly inhibited by the active oxygen scavengers histidine, tryptophan and N-acetyl-L-cysteine. Conclusion: Chemical modification of RB to RBD for tumor accumulation significantly increased the sonodynamically induced antitumor effect of RB.