Oxygen-Deficient Black Titania for Synergistic/Enhanced Sonodynamic and Photoinduced Cancer Therapy at Near Infrared-II Biowindow

Abstract

The conventional inorganic semiconductors are not suitable for in vivo therapeutic nanomedicine because of the lack of an adequate and safe irradiation source to activate them. This work reports on the rational design of titania (TiO)-based semiconductors for enhanced and synergistic sono-/photoinduced tumor eradication by creating an oxygen-deficient TiO layer onto the surface of TiO nanocrystals, which can create a crystalline-disordered core/shell structure (TiO@TiO) with black color. As found in the lessons from traditional photocatalysis, such an oxygen-deficient TiO layer with abundant oxygen defects facilitates and enhances the separation of electrons (e) and holes (h) from the energy-band structure upon external ultrasound irradiation, which can significantly improve the efficacy of sono-triggered sonocatalytic tumor therapy. Such an oxygen-deficient TiO layer can also endow black titania nanoparticles with high photothermal-conversion efficiency (39.8%) at the NIR-II biowindow (1064 nm) for enhanced photothermal hyperthermia. Both in vitro cell level and systematic in vivo tumor-bearing mice xenograft evaluations have demonstrated the high synergistic efficacy of combined and enhanced sonodynamic therapy and photothermal ablation as assisted by oxygen-deficient black titania, which has achieved complete tumor eradication with high therapeutic biosafety and without obvious reoccurrence. This work not only provides the paradigm of high therapeutic efficacy of a combined sono-/photoinduced tumor-treatment protocol but also significantly broadens the nanomedical applications of semiconductor-based nanoplatforms by rational design of their nanostructures and control of their physiochemical properties.

Nanocatalytic Medicine

“…Thus, from a mechanistic perspective, PDT can be considered as photocatalytic ROS‐generating process in the presence of organic/inorganic photocatalysts, and its development also benefits from the theoretical/technological advances in the field of photocatalysis. For example, the design principles of highly efficient photocatalysts are instructive for the fabrication of next‐generation PSs, such as the defect engineering of semiconductors to elevate ROS‐generating efficiency in PDT …”

BSA‐IrO2: Catalase‐like Nanoparticles with High Photothermal Conversion Efficiency and a High X‐ray Absorption Coefficient for Anti‐inflammation and Antitumor Theranostics

“…Furthermore,t he photothermal effect of BSA-IrO 2 NPs was evaluated by recording the temperature of aqueous solutions containing BSA-IrO 2 NPs at various concentrations under the irradiation of an 808 nm laser with adigital thermometer;aconcentration-( Figure 2c) and laser-power-dependent increase of the photothermal effect was observed (see Figure S10). Thet emperature of the aqueous solution of BSA-IrO 2 NPs (6 mm)c ould be increased to 69.8 8 8Cw ithin 10 min upon irradiation (1.3 Wcm À2 ), with good stability (see Figure S11) and aphotothermal conversion efficiencyo f6 7.8 %( see Figure S12), [15] which is higher than that of most reported photothermal 16] possibly owing to oxygen-deficiency-enhanced LSPR effects and nonradiative recombination of photogenerated charge carriers [17] as well as ah igh molar extinction coefficient (see Figure S13). …”

Ultrathin Molybdenum Carbide MXene with Fast Biodegradability for Highly Efficient Theory‐Oriented Photonic Tumor Hyperthermia

“…Until now, despite fast development of NIR II light in biomedical applications, nanosized PTAs that are known to exhibit the desirable activity in the NIR II biowindow are still rare, which are mainly limited to platinum nanoparticles, gold nanomaterials,1a carbon nanotubes, silver sulfide nanocrystals, copper sulfide‐base nanocomposites, titania nanoparticles, and some organic‐conjugated polymer particles . Although the significant progress has been achieved in PTT, merely several successful cases have been put into practical application most likely because of the unclear long‐period toxicity of these PTAs .…”