Near-infrared BODIPY-paclitaxel conjugates assembling organic nanoparticles for chemotherapy and bioimaging.

Self-assembly of organic molecules has attracted more and more attention because of precise molecular structure and multifarious synthesis chemistry. Herein, near-infrared brominated boron-dipyrromethenes (BODIPY) paclitaxel conjugate (BrBDP-2PTX) was synthesized. BrBDP-2PTX could self-assemble into uniform spherical nanoparticles (BrBDP-2PTX NPs) via nanoprecipition method. The obtained nanoparticles showed satisfying stability in aqueous solution and 10% fetal bovine serum (FBS) containing phosphoric acid buffer solution (PBS). Moreover, BrBDP-2PTX NPs could make rapid enzyme response to Proteinase K as evidenced by the obvious changes in size and size distribution. BrBDP-2PTX NPs could be internalized by the HeLa cells and exhibited potent cytotoxicity toward tumor cells (human cervical carcinoma cells and liver hepatocellular carcinoma cells) as revealed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assays and live/dead staining. Furthermore, in vivo experiments indicated BrBDP-2PTX NPs could be used as efficient bioimaging agents without causing any systemic toxicity. This work highlights the potential of using self-assembly of small organic molecules to develop functional nanomaterials.