"Spark" PtMnIr Nanozymes for Electrodynamic-Boosted Multienzymatic Tumor Immunotherapy.

Multienzyme-mimicking redox nanozymes capable of efficient reactive oxygen species (ROS) generation and cellular homeostasis disruption are highly pursued for cancer therapy. However, it still faces challenges from the complicate tumor microenvironment (TME) and high chance for tumor metastasis. Herein, well-dispersed PtMnIr nanozymes are designed with multiple enzymatic activities, including catalase (CAT), oxidase (OXD), superoxide dismutase (SOD), peroxidase (POD), and glutathione peroxidase (GPx), which continuously produce ROS and deplete glutathione (GSH) concurrently in an "inner catalytic loop" way. With the help of electrodynamic stimulus, highly active "spark" species (Ir3+ and Mn3+) are significantly increased, resulting in an effective cascade enzymatic and electrodynamic therapy. Moreover, the cyclic generation of ROS can also facilitate ferroptosis and apoptosis in tumor cells, boosting synergistic therapy. Importantly, lung metastasis inhibition is found, which confirms efficient immunotherapy by the combined effect of immunogenic cell death (ICD) and Mn2+-induced cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase (cGAS)-stimulator of interferon genes (cGAS-STING) pathway, contributing great potential in the treatment of malignant tumors.

Corrigendum to "A facile room temperature method to recycle Cd from CdS" [Heliyon 9(4) (April 2023) e15229].

[This corrects the article DOI: 10.1016/j.heliyon.2023.e15229.].

Dual enzyme-like Co-FeSe2 nanoflowers with GSH degradation capability for NIR II-enhanced catalytic tumor therapy.

Nanozymes mediated catalytic therapy can produce toxic reactive oxygen species (ROS) and destroy the metabolic balance of tumor cells, providing a new direction for cancer treatment. However, the catalytic efficiency of a single nanozyme is limited by the complexity of the tumor microenvironment (hypoxia, GSH overexpression, etc.). In order to overcome these problems, we designed flower-like Co-doped FeSe2 (Co-FeSe2) nanozymes by a simple wet chemistry method. Co-FeSe2 nanozymes not only exhibit high POD and OXD-mimicking activities for facile kinetics, but also effectively consume over-expressed glutathione (GSH), inhibiting the consumption of generated ROS and destroying the metabolic balance of the tumor microenvironment. These catalytic reactions trigger cell death through apoptosis and ferroptosis dual pathways. More importantly, under the NIR II laser irradiation, the catalytic activities of Co-FeSe2 nanozymes are boosted, confirming the photothermal and catalytic synergistic tumor therapy. This study takes advantage of self-cascading engineering that offers new ideas for designing efficient redox nanozymes and promoting their clinical translation.

A facile room temperature method to recycle Cd from CdS.

Cadmium-based semiconductors have a wide range of applications in light-emitting, energy conversion, photodetection and artificial photosynthesis. With the concern about the potential toxicity of Cd, it is necessary to recycle the element from the Cd based semiconductors. Commonly, the precipitation of Cd cations with S2- is deemed as the end point of recycling. However, actually, CdS is easy to be oxidized and released into the environment and accumulate in the food chain. It still remains challenges on how to refine the Cd element and convert it to the raw material. Herein, we demonstrate a facile room temperature method for recycling Cd from CdS. Cd can be produced from CdS within 3 h with the help of the lithium-ethylenediamine solution. DFT calculations further confirm that the high surface energy of (100) and (101) planes are selectively attacked by the solvated electrons in the solution, which is in good accordance with the XRD, STEM-HAADF and XPS characterizations. With a total recovery efficiency of 88%, Cd is successfully recovered from the CdS powder. This method provides a new perspective on the treatment of Cd-based semiconductor waste, which is of great significance for the recycling of cadmium metal.

A facile synthesis of PEGylated Cu2O@SiO2/MnO2 nanocomposite as efficient photo-Fenton-like catalysts for methylene blue treatment.

The removal of toxic organic dyes from wastewater has received much attention from the perspective of environmental protection. Metal oxides see wide use in pollutant degradation due to their chemical stability, low cost, and broader light absorption spectrum. In this work, a Cu2O-centered nanocomposite Cu2O@SiO2/MnO2-PEG with an average diameter of 52 nm was prepared for the first time via a wet chemical route. In addition, highly dispersed MnO2 particles and PEG modification were realized simultaneously in one step, meanwhile, Cu2O was successfully protected under a dense SiO2 shell against oxidation. The obtained Cu2O@SiO2/MnO2-PEG showed excellent and stable photo-Fenton-like catalytic activity, attributed to integration of visible light-responsive Cu2O and H2O2-responsive MnO2. A degradation rate of 92.5% and a rate constant of 0.086 min-1 were obtained for methylene blue (MB) degradation in the presence of H2O2 under visible light for 30 min. Additionally, large amounts of •OH and 1O2 species played active roles in MB degradation. Considering the enhanced degradation of MB, this stable composite provides an efficient catalytic system for the selective removal of organic contaminants in wastewater.

Biodistribution, degradability and clearance of 2D materials for their biomedical applications.

Two-dimensional (2D) materials have evolved to be a class of rapidly advancing chemical entities in the biomedical field. Nevertheless, potential side effects and safety concerns severely limit their clinical translation. After administration, 2D materials cross multiple biological barriers and are distributed throughout the body. Only the portion that accumulates at the diseased sites exerts a therapeutic effect, whereas those distributed elsewhere may cause damage to healthy tissues and interference to normal physiological function of various organs. To achieve maximum therapeutic efficacy and minimum adverse effects simultaneously, the delivery of 2D materials must be targeted at diseased sites to reach therapeutic concentrations, and the materials must possess sufficient degradation and clearance rates to avoid long-term toxicity. Therefore, it is essential to understand the biodistribution and destiny of 2D materials in vivo. In this review, first, we provide a comprehensive picture of the strategies that are currently adopted for regulating the in vivo fate of 2D materials, including modulations of their size, surface properties, composition, and external stimuli. Second, we systematically review the biodistribution, degradation, and metabolism of several newly emerged 2D materials. Finally, we also discuss the development opportunities of 2D materials in the biomedical field and the challenges to be addressed.

A synergistic chemodynamic-photodynamic-photothermal therapy platform based on biodegradable Ce-doped MoOx nanoparticles.

Near-infrared light-induced catalysts are considered to be potential nanoagents for tumor therapy. Cerium (Ce) is a non-biotoxic lanthanide element and exhibits variable valence states for catalytic reactions. In this work, we report a one-step hydrothermal synthesis for Ce-doped MoOx (CMO) nanomaterials. The obtained CMO nanomaterials show high absorption in the NIR II regime and a high photothermal conversion efficiency of 67.7% (1064 nm). Moreover, due to the doping of Ce element, the consumption of hydrogen peroxide (H2O2) and glutathione (GSH) is boosted which enhances the chemodynamic and photodynamic therapy simultaneously. Under NIR II laser irradiation, the designed CMO nanocatalysts induce metabolism disruption and mitochondrial damage in the tumor cells. As-prepared CMO nanomaterials also show good biocompatibility and pH-responsive degradation behavior, which can be degraded rapidly under alkaline conditions (pH = 7.4) and remain stable in acidic solution (pH = 5.6). These properties make CMO nanomaterials ideal biodegradable nanotheranostic agents for synergistic chemodynamic-photodynamic-photothermal antitumor therapy.

Ultrasmall AgBiSe2 nanodots for CT/thermal imaging-guided photothermal tumor therapy in the NIR-II biowindow.

Stimulus-responsive ternary chalcogenide nanomaterials are regarded as promising 'all-in-one' nanotheranostics agents on account of their tunable band structures and multi-metal intrinsic properties. Herein, ultrasmall AgBiSe2 nanodots are prepared by a simple thermal injection method. It shows a narrow band gap of 0.91 eV and high absorption coefficient in the NIR-II biowindow, resulting in excellent photothermal performance. Under the irradiation of a 1064 nm laser, AgBiSe2 can induce the overexpression of intracellular heat shock protein (Hsp70) and cell apoptosis to inhibit the growth of tumor cells. The strong signal from CT/thermal imaging also provides guidance for tumor diagnosis. Importantly, AgBiSe2 can be rapidly excreted from the body, thus avoiding long term toxicity. This study presents the first biomedical application of AgBiSe2 nanodots in cancer treatment and extends the development of ternary chalcogenide-based semiconductor nanomedicine.

A Near-Infrared Light Triggered Composite Nanoplatform for Synergetic Therapy and Multimodal Tumor Imaging.

Transition-metal chalcogenide compounds with facile preparation and multifunctional elements act as ideal photothermal agents for cancer theranostics. This work synthesizes Cu7.2S4/5MoS2 composite nanoflowers and investigates the crystal growth mechanism to optimize the synthesis strategy and obtain excellent photothermal therapy agents. Cu7.2S4/5MoS2 exhibits a high photothermal conversion efficiency of 58.7% and acts as a theranostic nanoplatform and demonstrated an effective photothermal-chemodynamic-photodynamic synergetic therapeutic effect in both in vitro and in vivo tests. Moreover, Cu7.2S4/5MoS2 shows strong photoacoustic signal amplitudes and computed tomographic contrast enhancement in vivo. These results suggest a potential application of Cu7.2S4/5MoS2 composite nanoflowers as photo/H2O2-responsive therapeutic agents against tumors.

Tumor Microenvironment Responsive Biodegradable Fe-Doped MoOx Nanowires for Magnetic Resonance Imaging Guided Photothermal-Enhanced Chemodynamic Synergistic Antitumor Therapy.

Rational design of nanosystems that target tumor microenvironment have attracted widespread attention. However, it is still a great challenge to make a multifunctional nanoplatform that actively and selectively interacts with tumor microenvironment, without causing toxicity to surrounding normal tissues. Herein, the biodegradable Fe-doped MoOx (FMO) nanowires are designed as an anti-tumor nanoreagent that possesses great photothermal conversion ability (48.5%) and magnetic properties for T1 weighted magnetic resonance imaging (MRI). Also, FMO can be used as a chemodynamic therapy (CDT) reagent to effectively catalyze the decomposition of H2 O2 and produce hydroxyl radical (·OH). At the same time, the consumption of glutathione will also enhance the CDT effect. More importantly, FMO presents pH-dependent degradation behavior: rapid degradation at physiological pH, but relatively stable at acidic pH. In vivo anti-tumor experiment demonstrates that the FMO is able to effectively inhibit the tumor growth with minimal side effects. Generally speaking, these results indicate that the FMO has huge potential for MRI image-guided cancer therapy and promotes the clinical translation of nanodrugs.

Reduced graphene oxide/Bi4O5Br2 nanocomposite with synergetic effects on improving adsorption and photocatalytic activity for the degradation of antibiotics.

A photocatalyst based on the integration of reduced graphene oxide (rGO) with Bi4O5Br2 nanosheets was facilely prepared and was confirmed by transmission electron microscope, scanning electron microscope, X-ray diffraction and Raman spectroscopy. The integration of rGO can effectively improve the adsorption and the photocatalytic properties of Bi4O5Br2 nanosheets towards the target antibiotics under visible light irradiation. rGO/Bi4O5Br2 nanocomposite containing 1.0 wt% of rGO exhibits the optimal adsorption and photocatalytic activity towards ciprofloxacin (CIP), norfloxacin (NOR) and tetracycline (TC). The removal efficiencies of CIP, NOR and TC are 97.6%, 80.7% and 98.7%, which are higher than that obtained with Bi4O5Br2 nanosheets. The capture experiments and ESR data show that ·O2-, OH· and h+ are the main active species that participated in the photodegradation system. This work provides a simple strategy to integrate rGO with BixOyXz (X = Cl, Br, I) nanosheets to construct effective photocatalysts for the degradation of antibiotics.

Cu2ZnSnS4/MoS2-Reduced Graphene Oxide Heterostructure: Nanoscale Interfacial Contact and Enhanced Photocatalytic Hydrogen Generation.

Hydrogen generation from water using noble metal-free photocatalysts presents a promising platform for renewable and sustainable energy. Copper-based chalcogenides of earth-abundant elements, especially Cu2ZnSnS4 (CZTS), have recently arisen as a low-cost and environment-friendly material for photovoltaics and photocatalysis. Herein, we report a new heterostructure consisting of CZTS nanoparticles anchored onto a MoS2-reduced graphene oxide (rGO) hybrid. Using a facile two-step method, CZTS nanoparticles were in situ grown on the surface of MoS2-rGO hybrid, which generated high density of nanoscale interfacial contact between CZTS and MoS2-rGO hybrid. The photoexcited electrons of CZTS can be readily transported to MoS2 through rGO backbone, reducing the electron-hole pair recombination. In photocatalytic hydrogen generation under visible light irradiation, the presence of MoS2-rGO hybrids enhanced the hydrogen production rate of CZTS by 320%, which can be attributed to the synergetic effect of increased charge separation by rGO and more catalytically active sites from MoS2. Furthermore, this CZTS/MoS2-rGO heterostructure showed much higher photocatalytic activity than both Au and Pt nanoparticle-decorated CZTS (Au/CZTS and Pt/CZTS) photocatalysts, indicating the MoS2-rGO hybrid is a better co-catalyst for photocatalytic hydrogen generation than the precious metal. The CZTS/MoS2-rGO system also demonstrated stable photocatalytic activity for a continuous 20 h reaction.

Morphology-Controlled Synthesis of Au/Cu2FeSnS4 Core-Shell Nanostructures for Plasmon-Enhanced Photocatalytic Hydrogen Generation.

Copper-based chalcogenides of earth-abundant elements have recently arisen as an alternate material for solar energy conversion. Cu2FeSnS4 (CITS), a quaternary chalcogenide that has received relatively little attention, has the potential to be developed into a low-cost and environmentlly friendly material for photovoltaics and photocatalysis. Herein, we report, for the first time, the synthesis, characterization, and growth mechanism of novel Au/CITS core-shell nanostructures with controllable morphology. Precise manipulations in the core-shell dimensions are demonstrated to yield two distinct heterostructures with spherical and multipod gold nanoparticle (NP) cores (Au(sp)/CITS and Au(mp)/CITS). In photocatalytic hydrogen generation with as-synthesized Au/CITS NPs, the presence of Au cores inside the CITS shell resulted in higher hydrogen generation rates, which can be attributed to the surface plasmon resonance (SPR) effect. The Au(sp)/CITS and Au(mp)/CITS core-shell NPs enhanced the photocatalytic hydrogen generation by about 125% and 240%, respectively, compared to bare CITS NPs.

Significant enhancement in photocatalytic reduction of water to hydrogen by Au/Cu2 ZnSnS4 nanostructure.

Enhanced photocatalytic activities by Au core Novel Au/Cu2 ZnSnS4 core/shell nanoparticles (NPs) are synthesized for the first time via wet chemistry approach. The insertion of Au core into CZTS NPs dramatically enhances light absorption due to surface plasmon resonance effect, especially in the Vis-NIR region. Au/CZTS core/shell NPs show much higher photocatalytic activities for hydrogen evolution compared with other CZTS nanostructures.

Synchronous determination of mercury (II) and copper (II) based on quantum dots-multilayer film.

A sensitive sensor for mercury (II) and copper (II) synchronous detection was established via the changed photoluminescence of CdTe quantum dots (QDs) multilayer films in this work. QDs were deposited on the quartz slides to form QDs-multilayer films by electrostatic interactions with poly(dimethyldiallyl ammonium chloride) (PDDA). Hg(2+) or Cu(2+) could quench the photoluminescence of the QDs-multilayer films, and glutathione (GSH) was used to remove Hg(2+) or Cu(2+) from QDs-multilayer films due to strong affinity of GSH-metal ions, which resulted in the recovered photoluminescence of QDs-multilayer films. There are good linear relationships between the metal ions concentration and the photoluminescence intensity of QDs in the quenched and recovered process. It was found that the Stern-Volmer constants for Hg(2+) are higher than that for Cu(2+). Based on different quenching and recovery constant between Hg(2+) and Cu(2+), the synchronous detection of Hg(2+) and Cu(2+) can be achieved. The linear ranges of this assay were obtained from 0.005 to 0.5 µM for Hg(2+) and from 0.01 to 1 µM for Cu(2+), respectively. And the artificial water samples were determined by this method with satisfactory results, the recoveries for Hg(2+) and Cu(2+) ions were found in the range of 90.4-106.4%. To the best of our knowledge, it is the first report about the synchronous detection of Hg(2+) and Cu(2+) by using quenched and recovered photoluminescence of quantum dots multilayer films.