Rose Bengal (RB) demonstrates toxicity to malignant cells and may induce an immune response. The purpose of this study is to attach RB to a microbubble (MB) to facilitate delivery through sonodynamic therapy (SDT) using MBs and low intensity ultrasound to release drug at a target site. A MB shell is made up of surfactants each with a hydrophilic head and hydrophobic tail. Typically, a hydrophobic drug is incorporated into the bubble shell. Since RB is water soluble, when typical encapsulation was attempted, a series of wash steps resulted in no drug loading. The later attempt focused on RBs negative charge. By adding the surfactant cetyltrimethyl ammonium bromide (CTAB) the MB becomes positively charged, and a RB wash allows the RB to be attached. Drug loading was compared between one batch loaded with CTAB and one without, the same wash steps were followed for each batch. In the CTAB batch, 2.6 mg/mL of RB were loaded compared to no evidence of loading on the batch without CTAB. These results were confirmed using both a plate reader and a fluorescent microscope. Results gave a MB diameter of 2.1 µm at a concentration of MB/mL The results demonstrate excellent potential of this method to produce RB-MB for use in SDT.
