Integration of IR-808 and thiol-capped Au-Bi bimetallic nanoparticles for NIR light mediated photothermal/photodynamic therapy and imaging.

Near infrared (NIR) light detonated phototherapy for cancer treatment based on photothermal therapy (PTT) and photodynamic therapy (PDT) has attracted increasing attention owing to its deep tissue penetration. However, the low absorption ability and therapeutic efficiency of the photosensitive drug have restricted the development of phototherapy to a great degree. Herein, a kind of IR808 dye sensitized glutathione (GSH) cladded Au-Bi bimetallic nanoparticles (Au-Bi-GSH@IR808) was prepared to enhance the inhibition effect of tumors. In this nanoplatform, the construction of GSH cladded Au-Bi bimetallic nanoparticles can effectively generate 1O2 while exhibiting outstanding photothermal conversion efficiency (η = 34.2%) upon 808 nm laser irradiation. Furthermore, IR808 as a small molecule dye endows the Au-Bi-GSH@IR808 with a higher 808 nm light absorption ability and stronger photothermal and photodynamic effects. The IR808 sensitized Au-Bi bimetallic nanoparticles with a small size (5 nm), hydrophilia and dispersible nature, exhibit a noticeably enhanced therapeutic peculiarity. Additionally, the prominent CT imaging property of Au-Bi-GSH@IR808 means it is expected to be used as a CT imaging contrast agent in clinical applications. The results of the in vitro and in vivo experiments indicate that the synthesized nanoparticles have an excellent ablation effect on cancer cells, and they are expected to be widely used in the accurate diagnosis and treatment of cancer.

Construction of thiol-capped ultrasmall Au-Bi bimetallic nanoparticles for X-ray CT imaging and enhanced antitumor therapy efficiency.

Thiol capped gold nanoparticles with small size, high dispersity, and broad light absorption covering ultraviolet (UV) to near infrared (NIR) region have been developed for catalysis, fluorescence imaging and photodynamic therapy (PDT). The constitution of the metal core in such nanoparticles can strongly influence the luminescence, catalysis, and stability properties. However, to date, a corresponding investigation of the influence of the metallic core on the generation of reaction oxygen species (ROS) and its therapeutic efficiency towards tumor cells remains to be lacking. Herein, we fabricated bimetallic nanoparticles by introducing bismuth into captopril capped gold nanoparticles. Surprisingly, the introduction of the Bi was found enhance the photothermal effect of the nanoparticles to a great extent, and the variation trends for the thermal effect, ROS generation rate, and tumor cell inhibition effect were found to disparate with the changes in the Au and Bi composition. The origin of the photothermal effect was deduced through density functional theory calculations based on microscopic construction. Combined with the intrinsic photodynamic effect, the bimetallic nanoparticles showed an outstanding tumor cell inhibition effect. Furthermore, due to the excellent CT imaging property, our designed nanoparticles provide the exciting possibility to realize CT imaging guided and light-mediated tumor therapy.

SiO2@Cu7S4 nanotubes for photo/chemodynamic and photo-thermal dual-mode synergistic therapy under 808 nm laser irradiation.

Photodynamic therapy (PDT) is a light-based modality for tumor treatment that involves the generation of reactive oxygen species (ROS) by the combination of light, a photosensitizer, and molecular oxygen. Nevertheless, the therapeutic effects of PDT are limited by hypoxic conditions that worsen with oxygen consumption during the PDT process. Photo/chemodynamic therapy (PCDT) based on the Fenton reaction is one strategy to improve ROS generation, provided a highly effective Fenton reagent is developed. In this research, SiO2@Cu7S4 nanotubes (NTs) were synthesized as a PCDT agent. This double-valence metal-sulfide composite material can react with H2O2 at the tumor site. SiO2@Cu7S4 NTs can produce more ROS than the traditional PDT agents, and besides, they can also be used as a photothermal therapy (PTT) agent. SiO2@Cu7S4 NTs will trigger the PTT effect under 808 nm irradiation and generate a large amount of heat to eradicate cancer cells. This heat will also promote the PCDT effect by increasing the reaction rate. Thus, the SiO2@Cu7S4 NT is a suitable material for PCDT and PTT synergistic oncotherapy. The 808 nm laser is selected as the appropriate excitation source, providing adequate penetration and minimal harm to normal cells. The experimental data presented herein demonstrate the promising photosensitive, Fenton-like, and photothermal performance of SiO2@Cu7S4 NTs. Furthermore, the findings could promote the development of PCDT and PTT synergistic therapy. Thus, this research provides a feasible method to design a single, multifunctional material for cancer treatment.