Progress in Light‐Responsive Lanthanide Nanoparticles toward Deep Tumor Theranostics

Abstract

AbstractRecently, lanthanide nanoparticles have aroused widespread interest in cancer theranostics by virtue of their excellent photoresponsive performance in deep‐seated tumors. The abundant ladder‐like energy levels, controllable emission profiles, and unique photoluminescence properties make lanthanide nanoparticles highly efficient for deep skin‐penetration of near‐infrared (NIR) light, concentrating light energy in tumors with negligible scattering and minimal autofluorescence from biological tissues. High‐Z radio‐sensitization of lanthanide elements endows lanthanide nanoparticles with a high X‐ray attenuation coefficient, making them effective nanoprobes for X‐ray‐excited bioimaging and synchronous radiotherapy‐related treatments. In this review, comprehensive progressions including the synthesis, structural characteristics of lanthanide nanoparticles, and distinct optical excitation mechanisms with NIR and X‐ray triggers, are summarized. Advances in NIR‐excited and X‐ray‐triggered cancer imaging methods and therapies are described in detail, wherein NIR‐induced luminescence from upconversion nanoparticles and downconversion nanoparticles are introduced separately based on some typical sensitization. Finally, the challenges and opportunities of lanthanide nanoparticles as light‐triggered cancer theranostic candidates are discussed, whose translation from bench to bedside still has a long journey to go.