Synthesis and biological characterization of novel rose bengal derivatives with improved amphiphilicity for sono-photodynamic therapy.

Sono-Photodynamic therapy (SPDT) utilizing ultrasound and light has been demonstrated that this novel approach can lower dosage resulting in reduction of the potential side effects caused by sensitizers. Recently, a new formulation of rose bengal (RB) as an intralesional injection has completed clinical trials phase II for PDT treatment of melanoma cancer. However, the inherent unfavorable pharmacological properties of RB hindered its extensive clinical development. With the aim to identify new RB derivatives (RBDs) with enhanced photodynamic and sonodynamic anticancer efficiency, a series of amphiphilic RBDs have been designed, synthesized and biological characterized. Among them, RBD4 significantly improved cellular uptake and enhanced intracellular ROS generation efficiency upon light and ultrasound irradiation, resulting in dramatically improved anticancer potency. Notably, RBD4 has a relative potency similar to sinoporphyrin sodium (DVDMS), indicating its further potential application for SPDT.