pH-controlled photodynamic therapy

Researchers have made a breakthrough in photodynamic therapy. Photodynamic therapy utilizes a chemical reagent that targets a tumor and is activated to generate cell-killing singlet oxygen molecules by irradiating a site with red light. The research shows that by adding an amine-containing group to photosensitive bromo-fluoro-2-chelated azadipyrromethenes the level of selectivity can be increased by taking advantage of the slightly acidic pH inherent to tumor tissues.