Progress in Light‐Responsive Lanthanide Nanoparticles toward Deep Tumor Theranostics

Abstract

Recently, 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.

Progress and Viewpoints of Multifunctional Composite Nanomaterials for Glioblastoma Theranostics

“…The scheme of energy transfer from dopant to dopant is shown in Figure 4c. The quantum efficiency of the downconversion is higher than the upconversion system because of amount of energy loss during energy transportation [82]. Significant enhancement was achieved on the Er-doped nanoparticle by 675 folds.…”

Recent advances in functionalized upconversion nanoparticles for light-activated tumor therapy

“…Overall, combined immunotherapy provides a promising approach for the treatment of metastatic cancers. 128 …”

Upconversion Nanocrystals with High Lanthanide Content: Luminescence Loss by Energy Migration versus Luminescence Enhancement by Increased NIR Absorption

“…Ytterbium as sensitizer and erbium as activator ions were chosen to enable the energy transfer upconversion process (Figure 1a) leading to luminescence emissions in the green and red range of the electromagnetic spectrum, attractive for a broad variety of applications in biosensing and theranostics. [54][55][56] For this, core-shell nanoparticles with high sensitizer and activator content were synthesized. Those UCNPs consist of β-NaYbF 4 (20%Er) equipped with NaYF 4 .…”