Red Phosphorus Decorated TiO₂ Nanorod Mediated Photodynamic and Photothermal Therapy for Renal Cell Carcinoma

Abstract

most frequent among females (the ratio between affected men and women is 2:1). [1,2] Approximately 270 000 new cases of RCC and 116 000 RCC-related deaths are reported worldwide per year. [3] Among the reported patients, clear cell RCC (ccRCC) cases account for 70-80%. [4] The cure rate of advanced ccRCC patients with a 5-year survival rate is as low as 11.7%, so efficient treatment is necessary. [5,6] Surgery is the most common treatment for ccRCC. However, with the high invasiveness and high resistance to chemotherapeutic agents, advanced ccRCC is difficult to cure once metastasis occurs. [7] In recent years, therapeutics focused on killing cancer cells via nanomaterial-based phototoxicities, such as photodynamic therapy (PDT) and photothermal therapy (PTT), have been widely studied. [8,9] PDT is an effective clinical approach that uses a photoactivatable compound as a photosensitizer and irradiation with appropriate wavelength light. Under illumination, the photosensitizer can be activated as a generator of reactive oxygen species (ROS) to kill cancer cells efficiently. PTT is also an effective means of cancer treatment, in which photothermal agents can catalyze the production of local heat under illumination to kill cancer cells. [9] PTT can increase the blood flow and Clear cell renal cell carcinoma (ccRCC) is a serious and tenacious disease. Photodynamic therapy (PDT) and photothermal therapy (PTT) are effective means of cancer treatment. However, PDT combined with PTT has been rarely reported in ccRCC treatment. In the present study, by developing the core-shell structured TiO 2 @red phosphorus nanorods (TiO 2 @RP NRs) as a photosensitizer, the feasibility and effectiveness of synchronous PDT and PTT treatments for ccRCC are demonstrated. The core-shell structured TiO 2 @ RP NRs are synthesized to drive the PDT and PTT for ccRCC, in which the RP shell is the sensitizer even in the near-infrared (NIR) region. The optimized TiO 2 @RP NRs can respond to NIR and produce local heat under irradiation. The NRs are estimated in ccRCC treatments via cell counting kit-8 assay, propidium iodide staining, qRT-PCR, and reactive oxygen species (ROS) probes in vitro, while terminal deoxynucleotidyl transferase dUTP nick-end labeling is conducted in vivo. After NIR irradiation, TiO 2 @RP NRs can efficiently kill ccRCC cells by producing local heat and ROS and cause low injury to normal kidney cells. Furthermore, treatment with TiO 2 @RP NRs and NIR can kill significant numbers of deep-tissue ccRCC cells in vivo. This work highlights a promising photo-driven therapy for kidney cancer.

Emerging photodynamic/sonodynamic therapies for urological cancers: progress and challenges

“…There is a large demand for new treatments for RCC. A facilely prepared core–shell structured TiO 2 @red phosphorus nanorods (TiO 2 @RP NRs) that can effectively mediate the combined PDT and PTT for clear cell RCC (ccRCC) was reported [ 93 ]. Red phosphorus (RP), a new class of biophotocatalysts, displaying great absorption of NIR [ 156 ], was deposited onto the TiO 2 NR surface to extend the absorption range of TiO 2 @RP NRs to NIR.…”

Vacancy defect-promoted nanomaterials for efficient phototherapy and phototherapy-based multimodal Synergistic Therapy

“…The oxygen vacancy engineering provides a new strategy for constructing multifunctional nanomaterial and achieving efficient synergistic therapy. Thus, some oxygen vacancy-engineered nanomaterials have been developed to efficiently combine PDT and PTT to improve the phototherapeutic efficacy against tumor ( Sun et al, 2019 ; Wang X. et al, 2019 ; Maleki et al, 2021 ; Yang et al, 2021 ). For example, Xu et al ( Yang et al, 2021 ) synthesized the core−shelled TiO 2 @red phosphorus nanorods (TiO 2 @RP NRs) as a nanophotosensitizer for synergetic PDT and PTT, through the vaporization-deposition (VP) method.…”

“…Thus, some oxygen vacancy-engineered nanomaterials have been developed to efficiently combine PDT and PTT to improve the phototherapeutic efficacy against tumor ( Sun et al, 2019 ; Wang X. et al, 2019 ; Maleki et al, 2021 ; Yang et al, 2021 ). For example, Xu et al ( Yang et al, 2021 ) synthesized the core−shelled TiO 2 @red phosphorus nanorods (TiO 2 @RP NRs) as a nanophotosensitizer for synergetic PDT and PTT, through the vaporization-deposition (VP) method. It can be observed that more oxygen vacancies were created in nanosized TiO 2 core after the vaporization-deposition, which led to a significantly enhanced NIR absorption in the range of 640–1,100 nm.…”

Recent Advance of Nanomaterial-Mediated Tumor Therapies in the Past Five Years

“…In addition, photodynamic and photothermal therapy are usually applied in combination due to their synergistic tumor killing effect (Figure 2). Photothermal therapy generates heat locally can not only ablate tumor cells, but also accelerate blood circulation and accumulate oxygen in the tumor's hypoxic microenvironment to provide suitable conditions for photodynamic therapy (Yang et al, 2021). Guan et al prepared covalent organic framework nanoparticles with a particle size of ~140 nm that co-loaded the photosensitizer porphyrin and the photothermal agent naphthalocyanine.…”

“…Yang et al synthesized TiO 2 @RP nanorods with red phosphorus (RP) as the shell and TiO 2 as the core. After being irradiated with 808 nm NIR light for 5 min, the nanorods can reach 39.3-44.1 °C and induce the production of 1 O 2 , effectively killing cancer cells in deep tissues of renal cell carcinoma (Yang et al, 2021).…”