The synthesis of three water-soluble lactose-modified 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based photosensitizers with tumor-targeting capabilities is reported, including an investigation into their photodynamic therapeutic activity on three distinct cancer cell lines (human hepatoma Huh7, cervical cancer HeLa, and breast cancer MCF-7 cell lines). The halogenated BODIPY dyes exhibited a decreased fluorescence quantum yield compared to their non-halogenated counterpart, and facilitated the efficient generation of singlet oxygen species. The synthesized dyes exhibited low cytotoxicities in the dark and high photodynamic therapeutic capabilities against the treated cancer cell lines following irradiation at 530 nm. Moreover, the incorporation of lactose moieties led to an enhanced cellular uptake of the BODIPY dyes. Collectively, the results presented herein provide promising insights for the development of photodynamic therapeutic agents for cancer treatment.

In this study, a series of rationally designed emissive phenanthrene derivatives were synthesized and their aggregation-induced emission (AIE) properties in tetrahydrofuran (THF)/water mixtures were investigated. Two tetraphenylethene (TPE) segments were conjugated to both ends of the phenanthrene core at the para-positions and meta-positions, resulting in pTPEP and mTPEP derivatives, respectively. While the TPE-conjugated phenanthrene derivatives did not show any emission when dissolved in pure THF, they showed strong sky-blue emissions in water-THF mixtures, which is attributed to the restriction of intramolecular motions of TPE segments by aggregation. Furthermore, silica nanoparticles loaded with these AIE-active compounds were prepared and proved to be promising intracellular imaging agents.