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 μM 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.