An optimized lanthanide-chlorophyll nanocomposite for dual-modal imaging-guided surgery navigation and anti-cancer theranostics.

In this research, an optimized phosphor combined with naturally green chlorophyll (Phosphor-Chlorophyll, denoted as Ph-chl) was designed for dual-modal luminescence-guided anti-tumor surgery and photodynamic therapy (PDT). A genetic algorithm (GA) is used to solve the "low up-conversion luminescence (UCL) and short-wavelength infrared (SWIR) intensity" problem by coding the proportions of elements in the phosphor in order to find the optimal phosphor with enhanced red UCL emission and SWIR luminescence using Yb/Er in the core and Yb/Nd in the shell. Moreover, when phosphors with different emission light colors (blue and green) are combined with chlorophyll as the control, the results indicate that phosphors with red emission as the energy donor have high PDT efficiency to activate the chlorophyll for reactive oxygen species (ROS) production. Additionally, due to the enhanced penetration and retention (EPR) effect, the as-synthesized Ph-chl could be used for surgery navigation with a higher SWIR imaging effect focusing on cancer rather than normal tissues and paracancerous tissue. Thus, the high dual-modal luminescence guided surgery properties of the final optimized phosphor will promote its further use in minimally-invasive endoscopic clinical surgery navigation.