The ultrahigh concentration of glutathione (GSH) inside tumors destroys reactive oxygen species (ROS)‐based therapy, improving the outcome of chemodynamic therapy (CDT)‐enhanced sonodynamic therapy (SDT) by depleting GSH is full of great challenge. Herein, PtCu3 nanocages are first reported as acting as a sonosensitizer with highly efficient ROS generation under ultrasound irradiation. In addition, PtCu3 nanocages can act as horseradish peroxidase‐like nanozymes, catalyzing the decomposition of H2O2 into •OH under acidic conditions for CDT. Surprisingly, PtCu3 nanocages can act as another kind of nanozyme, mimicking glutathione peroxidase (GSH‐Px), which plays an important role in accelerating GSH depletion by oxidizing molecules, further weakening the capacity of tumor cells scavenging ROS by GSH. Both in vitro and in vivo studies demonstrate that PtCu3 nanocages perform well in reducing GSH level for CDT‐enhanced SDT. Moreover, utilizing the high absorption in the near‐infrared region and strong X‐ray attenuation ability, the PtCu3 nanocages are able to conduct photoacoustic/computed tomography dual‐modal imaging‐guided combined cancer therapy. It is worth mentioning that PtCu3 nanocages cause minimal toxicity to normal tissues at therapeutic doses. This work highlights the use of PtCu3 nanocages for effective CDT‐enhanced SDT via GSH depletion.
Ultrasound (US)-triggered
sonodynamic therapy (SDT) that enables
noninvasive treatment of large internal tumors has attracted widespread
interest. For improvement in the therapeutic responses to SDT, more
effective and stable sonosensitizers are still required. Herein, ultrafine
titanium monoxide nanorods (TiO1+x
NRs)
with greatly improved sono-sensitization and Fenton-like catalytic
activity were fabricated and used for enhanced SDT. TiO1+x
NRs with an ultrafine rodlike structure were successfully
prepared and then modified with polyethylene glycol (PEG). Compared
to the conventional sonosensitizer, TiO2 nanoparticles,
the PEG–TiO1+x
NRs resulted in
much more efficient US-induced generation of reactive oxygen species
(ROS) because of the oxygen-deficient structure of TiO1+x
NR, which predominantly serves as the charge trap
to limit the recombination of US-triggered electron–hole pairs.
Interestingly, PEG–TiO1+x
NRs also
exhibit horseradish-peroxidase-like nanozyme activity and can produce
hydroxyl radicals (•OH) from endogenous H2O2 in the tumor to enable chemodynamic therapy (CDT).
Because of their efficient passive retention in tumors post intravenous
injection, PEG–TiO1+x
NRs can be
used as a sonosensitizer and CDT agent for highly effective tumor
ablation under US treatment. In addition, no significant long-term
toxicity of PEG–TiO1+x
NRs was
found for the treated mice. This work highlights a new type of titanium-based
nanostructure with great performance for tumor SDT.
2D nanomaterials with unique nanosheet structures, large surface areas, and extraordinary physicochemical properties have attracted tremendous interest. In the area of nanomedicine, research on graphene and its derivatives for diverse biomedical applications began as early as 2008. Since then, many other types of 2D nanomaterials, including transition metal dichalcogenides, transition metal carbides, nitrides and carbonitrides, black phosphorus nanosheets, layered double hydroxides, and metal–organic framework nanosheets, have been explored in the area of nanomedicine over the past decade. In particular, a large surface area makes 2D nanomaterials highly efficient drug delivery nanoplatforms. The unique optical and/or X‐ray attenuation properties of 2D nanomaterials can be harnessed for phototherapy or radiotherapy of cancer. Furthermore, by integrating 2D nanomaterials with other functional nanoparticles or utilizing their inherent physical properties, 2D nanomaterials may also be engineered as nanoprobes for multimodal imaging of tumors. 2D nanomaterials have shown substantial potential for cancer theranostics. Herein, the latest progress in the development of 2D nanomaterials for cancer theranostic applications is summarized. Current challenges and future perspectives of 2D nanomaterials applied in nanomedicine are also discussed.
Nanozymes have become a new generation of antibiotics with exciting broad-spectrum antibacterial properties and negligible biological toxicity. However, their inherent low catalytic activity limits their antibacterial properties. Herein, Cu single-atom sites/N doped porous carbon (Cu SASs/NPC) is successfully constructed for photothermal-catalytic antibacterial treatment by a pyrolysis-etching-adsorption-pyrolysis (PEAP) strategy. Cu SASs/NPC have stronger peroxidase-like catalytic activity, glutathione (GSH)-depleting function, and photothermal property compared with non-Cu-doped NPC, indicating that Cu doping significantly improves the catalytic performance of nanozymes. Cu SASs/NPC can effectively induce peroxidase-like activity in the presence of H
2
O
2
, thereby generating a large amount of hydroxyl radicals (•OH), which have a certain killing effect on bacteria and make bacteria more susceptible to temperature. The introduction of near-infrared (NIR) light can generate hyperthermia to fight bacteria, and enhance the peroxidase-like catalytic activity, thereby generating additional •OH to destroy bacteria. Interestingly, Cu SASs/NPC can act as GSH peroxidase (GSH-Px)-like nanozymes, which can deplete GSH in bacteria, thereby significantly improving the sterilization effect. PTT-catalytic synergistic antibacterial strategy produces almost 100% antibacterial efficiency against
Escherichia coli
(
E. coli
) and methicillin-resistant
Staphylococcus aureus
(
MRSA
).
In vivo
experiments show a better PTT-catalytic synergistic therapeutic performance on MRSA-infected mouse wounds. Overall, our work highlights the wide antibacterial and anti-infective bio-applications of Cu single-atom-containing catalysts.
Sonodynamic therapy (SDT) is a new therapeutic method, which can kill malignant tumors by using sonosensitizers and low intensity ultrasound (US) simultaneously.
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