Nanoprobes with near-infrared persistent luminescence for <i>in vivo</i> imaging

TLDR

Fluorescence imaging is widely used for in vivo imaging but suffers from tissue autofluorescence and limited penetration of low‑wavelength excitation light. The authors aim to develop an alternative optical imaging method using persistent luminescent nanoparticles for small‑animal imaging. These nanoparticles are pre‑excited before injection, enabling real‑time tracking for over an hour without external illumination, and surface chemistry can direct them to the lung, liver, or maintain prolonged blood circulation. In a mouse model, the technique successfully identified tumor masses.

Abstract

Fluorescence is increasingly used for in vivo imaging and has provided remarkable results. Yet this technique presents several limitations, especially due to tissue autofluorescence under external illumination and weak tissue penetration of low wavelength excitation light. We have developed an alternative optical imaging technique by using persistent luminescent nanoparticles suitable for small animal imaging. These nanoparticles can be excited before injection, and their in vivo distribution can be followed in real-time for more than 1 h without the need for any external illumination source. Chemical modification of the nanoparticles' surface led to lung or liver targeting or to long-lasting blood circulation. Tumor mass could also be identified on a mouse model.