Zheng Ruan,Yangyang Zhao,Pan Yuan,Le Liu,Yucai Wang,Lifeng Yan
Drug-free biocompatible nanoparticles with photosensitizers as both diagnostic and therapy agents represent an emerging approach for imaging-guided photodynamic therapy (PDT). Here, a NSH-active boron-dipyrromethene (BODIPY) derivative with a bromine substituted (BODIPY-Br2, for simplicity, BDP-Br) photosensitizer was synthesized; it showed a high ability of generating reactive oxygen species (ROS) upon irradiation for PDT and near infrared fluorescence imaging ability. Then, a simple PEGylated BDP-Br (PEG-BDP) as a kind of macro photosensitizer was prepared which showed superior cellular uptake ability, high efficiency of imaging, and curing with PDT therapy in vitro and in vivo. After administration with a 4T1 orthotopic tumor model, the resultant PEG-BDP showed prolonged blood circulation and preferential tumor accumulation compared with free BDP-Br molecules. Once accumulated in tumor tissues, therapeutic effects of PEG-BDP could significantly suppress primary tumor growth and has no evident side effects at a weak irradiation energy as low as 35 mW cm−2 for 20 minutes. The designation of this simple structure macro photosensitizer agent provides new avenues for efficient imaging-guided cancer PDT.
Near infrared (NIR) imaging-guided photodynamic therapy (PDT) is attractive, especially the utilization of one dye as both a photosensitizer and fluorescent probe, and the as-synthesized BODIPY-Br2 molecule is a candidate. Here, a galactose targeted amphiphilic copolymer of a polypeptide was synthesized and its micelles work as nanocarriers for BODIPY for targeting the NIR imaging-guided PDT of hepatoma cancer cells. At the same time, BODIPY could light up the cytoplasm for real-time imaging and kill cancer cells when the light was switched on. In vitro tests performed on both HepG2 and HeLa cells confirmed that the as-prepared PMAGP-POEGMA-PLys-B micelles showed efficient cell suppression of the cells with galactose receptors in the presence of light under an extremely low energy density (6.5 J cm−2). This protocol highlights the potential of polypeptides as biodegradable carriers for NIR image-guided and confined targeting photodynamic therapy.