Trifluoromethyl-pyrrolidone phthalocyanine nanoparticles for targeted lipid droplet imaging and in vitro photodynamic therapy in breast cancer cells.

Lipid droplets (LDs) serve as vital subcellular organelles, crucial for the maintenance of lipid and energy homeostasis within cells. Their visualization is of significant value for elucidating the intricate interactions between LDs and other cellular organelles. Despite the importance of LDs, the literature on the utilization of phthalocyanine-based photosensitizers for targeted LD imaging and two-photon imaging-guided photodynamic therapy (PDT) remains sparse. In this study, we have designed and synthesized trifluoromethyl-pyrrolidone silicon phthalocyanine (PyCFSiPc). To enhance the water solubility of PyCFSiPc and improve its tumor cells accumulation, we employed 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000] (DSPE-mPEG) as a nanocarrier, thereby formulating DSPE@PyCF3SiPc nanoparticles. Our in vitro experiments in MCF-7 cells demonstrated that DSPE@PyCFSiPc selectively targets and visualizes LDs, offering a reliable tool for tracking their dynamic movement. Moreover, DSPE@PyCFSiPc demonstrates considerable phototoxicity against MCF-7 cells subjected to PDT underscoring its potential as an effective therapeutic agent. In conclusion, DSPE@PyCFSiPc presents itself as a promising novel probe for the dual purpose of monitoring the dynamic movement of LDs and guiding imaging-assisted PDT. The development of this nanoparticle system not only advances our understanding of LD biology but also paves the way for innovative therapeutic strategies in oncology.