Unadulterated BODIPY nanoparticles for biomedical applications

4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) as the robust dyes have been widely applied in biomedical areas, especially for tumor imaging and phototherapy. Most of the BODIPY dyes are hydrophobic, so the nanoparticle formulations are imperative for their dispersion in physiological conditions. The nanoparticles are usually obtained in the presence of surfactants or auxiliaries. In recent years, our group and others have reported the pure BODIPY nanoparticles (BODIPY NPs), which were prepared via the self-assembly of BODIPY molecules in aqueous solution without addition of any surfactants. These BODIPY NPs possess excellent colloid stability, near 100% of BODIPY, and particular physicochemical properties, which could be potentially used in cancer treatment and diagnosis. In this review, we will summarize and highlight the reported unadulterated organic nanoparticles based on BODIPY dyes and their application in bioimaging and cancer therapy to provide a paradigm of rational design of novel BODIPY photosensitizers for biomedical applications.