Biocompatible PLNP-GNR composite nanoplatforms for monitoring deep-tissue photothermal therapy process

Abstract

Currently, it is still a challenge to construct an integrated multi-functional nanoplatform with autofluorescence-free bioimaging and temperature sensing and photothermal therapy (PTT) for tumors located at 10 mm below the surface of local tissue (deep tissue) using gold nanorods (GNRs). Herein, through the self-assembly and surface modification of persistent luminescent nanoparticles (PLNPs) and GNRs using hexadecyl trimethyl ammonium bromide (CTAB) and phosphotungstic acid (PW12) molecules, biocompatible PLNP-GNR composite nanoplatforms were constructed to simultaneously monitor autofluorescence-free bioimaging and temperature change during in vitro and in vivo PTT process using a single wavelength (635 nm) light excitation strategy. Especially, the nanoplatforms demonstrated that the local-tissue temperature can increase by 26 °C under 635 nm excitation (0.8 W·cm−2) and the photothermal conversion efficiency is ~37%. Among them, PLNPs were acted as optical probes for NIR bioimaging and ratiometric nanothermometer and the temperature sensitivity reaches to ~0.064 K−1. This study is helpful for reducing photodamage to normal tissue through the accurate control of excitation light power during deep-tissue PTT process.