Pluronic micelle-encapsulated red-photoluminescent chlorophyll derivative for biocompatible cancer cell imaging

Abstract Herein three synthesized chlorophyll derivatives (ZnChl-1, H 2 Chl-2, ZnChl-2) featuring hydrophilic hydroxy/carboxy groups were employed as precursors for fluorescent organic nanoparticles (NPs) with biocompatible Pluronic F127 as the encapsulation matrix for the first time. Such red NPs exhibited broad absorption bands and high hydrophilicity. Three chlorophyll derivatives with different substituent groups show varying degrees of changes after loaded with F127. As a result, ZnChl-2 exhibited the best retainable photoluminescence yield after encapsulation among these chlorophyll derivatives. It reveals that ZnChl-2@F127 is the most suitable NPs for cell imaging by comparing not only different three chlorophyll derivatives, but also free ZnChl-2 and ZnChl-2@F127. Application of ZnChl-2@F127 NPs for cancer cell imaging was successfully demonstrated and such chlorophyll-based NPs showed bright fluorescence signals and low toxicity. These studies indicate that the F127 encapsulated low-costed chlorophyll derivatives NPs are efficient fluorescent dyes for biological imaging. It is further directed towards photodynamic therapy based on chlorophyll derivatives.