pH-Activated Ce-Doped Molybdenum Oxide Nanoclusters for Tumor Microenvironment Responsive Photothermal and Chemodynamic Therapy

Abstract

Molybdenum-based nanomaterials have shown promise for anticancer treatment due to their strong photothermal and redox-activated capabilities. Herein, we have fabricated cerium-doped MoO x (Ce-MoOv) with tunable Mo/Ce molar ratios by a one-pot method and investigated their effect on chemodynamic therapy (CDT) and photothermal therapy (PTT). It is found that Ce-MoOv can self-assemble into nanoclusters in acidic conditions and the increasing Ce amount will generate oxygen vacancy defects and induce the valence change of Mo6+/Mo5+ and Ce4+/Ce3+, which leads to strong near-infrared absorption with high photothermal conversion efficiency of 71.31 and 49.86% for 808 and 1064 nm. Other than photothermal conversion, the materials demonstrate pH-/glutathione (GSH)-activated photoacoustic (PA) imaging capability in vitro. In addition, Ce-MoOv acts as a CDT reagent capable of converting endogenous H2O2 to two types of reactive oxygen species (•OH, 1O2) while depleting GSH. Ce-MoOv demonstrates an excellent therapeutic effect against HCT116 cells and effectively reduces the intracellular GSH level and significantly increases the number of reactive radicals under 1064 nm laser irradiation as compared with the no-laser group in vitro. This work provides a new paradigm using lanthanide-doped polymetallic oxides for pH-/GSH-responsive photothermal/chemodynamic therapy with PA imaging ability.

Thermal-Driven Curcumin Release Film with Dual-Mode Synergistic Antibacterial Behavior for Efficient Tangerine Preservation

“…The pattern of Fe-MoO x showed no significant difference from that of MoO x , and no obvious diffraction peaks associated with Fe appeared, which verified that Fe was only doped in MoO x. The broad diffraction peak in patterns indicated the poor crystallinity of MoO x . Full XPS spectra emphasize the existence of O, Mo, and Fe in Fe-MoO x (SI, Figure S2).…”

Advancing NIR-II Photothermal Antibacterial Capability of Polydopamine Nanoparticles through Iron-Doped Molybdenum Oxide Functionalization

“…24−27 Wen et al revealed strong light absorption capabilities of Ce-doped MoO x in both NIR I region (650−980 nm) and NIR II (1000−1700 nm) region. 28,29 Compared with the NIR-I region, the NIR-II region offers superior tissue penetration ability along with a higher maximum permissible exposure (MPE). 30−32 Therefore, photothermal therapy in the NIR-II region has received widespread application.…”

“…The transition metal oxide MoO x , renowned for its cost-effectiveness, nontoxicity, and biocompatibility, holds significant importance in the fields of sensing, catalysis, and energy storage due to the presence of multiple valence states in the Mo element. − The MoO x demonstrates local surface plasmon resonance (LSPR) effects, particularly the blue molybdenum-based oxides, exhibiting enhanced LSPR peaks attributed to valence transition and charge transfer between pentavalent and hexavalent molybdenum, resulting significant NIR absorption. − Wen et al revealed strong light absorption capabilities of Ce-doped MoO x in both NIR I region (650–980 nm) and NIR II (1000–1700 nm) region. , Compared with the NIR-I region, the NIR-II region offers superior tissue penetration ability along with a higher maximum permissible exposure (MPE). − Therefore, photothermal therapy in the NIR-II region has received widespread application. − Shi et al incorporated Fe into Mo-based oxides, resulting in the synthesis of uniform nanoparticles with a diameter of only 12.9 nm, which enabled efficient photothermal conversion in the NIR-II range and amplified the CDT effect . Additionally, the interaction between Mo 6+ and Mo 5+ facilitates efficient charge transfer and establishes a redox environment, which creates favorable conditions for Mo ions to react with substances such as H 2 O 2 , leading to the generation of ROS.…”