MOF-based nanoagent for self-illuminating photodynamic therapy

Photodynamic therapy (PDT) is a minimally invasive and local light-activated treatment for annihilating tumor tissues. However, it is often limited by the tissue penetration depth of common external light sources. To address this issue, we herein report a self-illuminating ZIF-90 MOF-based composite photosensitive system prepared using a combined one-pot self-assembly and post-synthetic modification (PSM) methodology. The obtained PME@Zn/Fe-ZIF-90-Lum consists of the Fe(II)-doped and luminol-decorated MOF host as well as the protoporphyrin IX dimethyl ester (PME) guest. Under the given conditions, the light, which is generated from the Fe(II)-catalysed luminol oxidation by endogenous H₂O₂, can in situ activate the encapsulated photosensitizer PME to produce reactive oxygen species (ROS) via a chemiluminescence resonance energy transfer (CRET) process. In the absence of an external light source, antitumor PDT is successfully realized and high phototoxicity is fully evidenced by in vitro and in vivo experiments.