Development of novel bifunctional agents with and without tumor imaging ability

Purpurinimides, derived from chlorophyll-a, are tumor avid, stable in vivo and show a strong absorption in the near IR region (700 nm) with a high singlet oxygen (>50%) producing efficiency. Such a characteristic could be useful in treating large and deeply seated tumors by photodynamic therapy (PDT). These long wavelength photosensitizers can be used as vehicles to deliver the imaging agents to tumors. Therefore, by linking suitable tumor imaging moiety with purpurinimide could produce a novel bifunctional agent, which could possess the desired photo physical properties for both tumor detection as well as photodynamic therapy. Such image guided therapy would represent an archetype for cancer treatment.