An enzymatically activated AND-gate DNA logic circuit for tumor cells recognition via multi-microRNAs detection.

The DNA-based logic circuit, constructed to mimic biochemical reaction networks, is highly significant in detecting biomarkers at the molecular level. The differences in the expression levels of microRNAs (miRNAs) within different types of cells provide hope for distinguishing cell subtypes. However, reliance on a single miRNA often leads to unreliable results. Herein, we constructed an enzyme-triggered cascade logic circuit based on the AND gate, which is capable of generating corresponding fluorescence signals in the presence of target miRNAs. The introduction of apurinic/apyrimidinic (AP) sites effectively reduces the likelihood of false signal generation. Amplification of the fluorescence signal relies on the catalytic hairpin assembly and the repetitive reuse of the multicomponent nucleic acid enzyme (MNAzyme). We demonstrated that the logic circuit can not only distinguish cancer cells from normal cells but also identify different types of cancer cells. The programmability of the logic circuits and the simplicity of the assay system allow us to modify the functional sequences to recognize different types of biomarkers, thus providing a reference for the identification of various cell subtypes.

Magnetically Controlled Photothermal, Colorimetric, and Fluorescence Trimode Assay for Gastric Cancer Exosomes Based on Acid-Induced Decomposition of CP/Mn-PBA DSNBs.

The accurate quantification of cancer-derived exosomes, which are emerging as promising noninvasive biomarkers for liquid biopsies in the early diagnosis of cancer, is becoming increasingly imperative. In our work, we developed a magnetically controlled photothermal, colorimetric, and fluorescence trimode aptasensor for human gastric cancer cell (SGC-7901)-derived exosomes. This sensor relied on CP/Mn-PBA DSNBs nanocomposites, created by decorating copper peroxide (CP) nanodots on polyethyleneimine-modified manganese-containing Prussian blue analogues double-shelled nanoboxes (PEI-Mn-PBA DSNBs). Through self-assembly, we attached CD63 aptamer-labeled CP/Mn-PBA DSNBs (Apt-CP/Mn-PBA DSNBs) to complementary DNA-labeled magnetic beads (cDNA-MB). During exosome incubation, these aptamers preferentially formed complexes with exosomes, and we efficiently removed the released CP/Mn-PBA DSNBs by using magnetic separation. The CP/Mn-PBA DSNBs exhibited high photoreactivity and photothermal conversion efficiency under near-infrared (NIR) light, leading to temperature variations under 808 nm irradiation, correlating with different exosome concentrations. Additionally, colorimetric detection was achieved by monitoring the color change in a 3,3',5,5'-tetramethylbenzidine (TMB) system, facilitated by PEI modification, NIR-enhanced peroxidase-like activity of CP/Mn-PBA DSNBs and their capacity to generate Cu2+ and H2O2 under acidic conditions. Moreover, in the presence of Cu2+ and ascorbic acid (AA), DNA sequences could form dsDNA-templated copper nanoparticles (CuNPs), which emitted strong fluorescence at around 575 nm. Increasing exosome concentrations correlated with decreases in temperature, absorbance, and fluorescence intensity. This trimode biosensor demonstrated satisfactory ability in differentiating gastric cancer patients from healthy individuals using human serum samples.

Sea Anemone-like Nanomachine Based on DNA Strand Displacement Composed of Three Boolean Logic Gates: Diversified Input for Intracellular Multitarget Detection.

Efficient and accurate acquisition of cellular biomolecular information is crucial for exploring cell fate, achieving early diagnosis, and the effective treatment of various diseases. However, current DNA biosensors are mostly limited to single-target detection, with few complex logic circuits for comprehensive analysis of three or more targets. Herein, we designed a sea anemone-like DNA nanomachine based on DNA strand displacement composed of three logic gates (YES-AND-YES) and delivered into the cells using gold nano bipyramid carriers. The AND gate activation depends on the trigger chain released by upstream DNA strand displacement reactions, while the output signal relies on the downstream DNAzyme structure. Under the influence of diverse inputs (including enzymes, miRNA, and metal ions), the interconnected logic gates simultaneously perform logical analysis on multiple targets, generating a unique output signal in the YES/NO format. This sensor can successfully distinguish healthy cells from tumor cells and can be further used for the diagnosis of different tumor cells, providing a promising platform for accurate cell-type identification.

Proximity hybridization induced molecular machine for signal-on electrochemical detection of α-synuclein oligomers.

α-synuclein oligomer is a marker of Parkinson's disease. The traditional enzyme-linked immunosorbent assay for α-synuclein oligomer detection is not conducive to large-scale application due to its time-consuming, high cost and poor stability. Recently, DNA-based biosensors have been increasingly used in the detection of disease markers due to their high sensitivity, simplicity and low cost. In this study, based on the DNAzyme-driven DNA bipedal walking method, we developed a signal-on electrochemical sensor for the detection of α-syn oligomers. Bipedal DNA walkers have a larger walking area and faster walking kinetics, providing higher amplification efficiency compared to conventional DNA walkers. The DNA walker is driven via an Mg2+-dependent DNAzyme, and the binding-induced DNA walker will continuously clamp the MB, resulting in the proliferation of Fc confined near the GE surface. The linear range and limit of detection were 1 fg/mL to 10 pg/mL and 0.57 fg/mL, respectively. The proposed signal-on electrochemical sensing strategy is more selective. It will play a significant role in the sensitive and precise electrochemical analysis of other proteins.

Synergistic action of cavity and catalytic sites in etched Pd-Cu2O octahedra to augment the peroxidase-like activity of Cu2O nanoparticles for the colorimetric detection of isoniazid and ascorbic acid.

Despite the widespread use of nanozyme-based colorimetric assays in biosensing, challenges such as limited catalytic efficiency, inadequate sensitivity to analytes, and insufficient understanding of the structure-activity relationship still persist. Overcoming these hurdles by enhancing the inherent enzyme-like performance of nanozymes using the unique attributes of nanomaterials is still a significant obstacle. Here, we designed and constructed Pd-Cu2O nanocages (Pd-Cu2O NCs) by selectively etching the vertices of the copper octahedra to enhance the peroxidase-like (POD-like) activity of Cu2O nanoparticles. The improved catalytic activity of Pd-Cu2O NCs was attributed to their high specific surface area and abundant catalytic sites. Mechanistic studies revealed that reactive oxygen species (ROS) intermediates (•OH) were generated through the decomposition of H2O2, resulting in POD-like activity of the Pd-Cu2O NCs. The designed Pd-Cu2O NCs can oxidize 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of H2O2, producing a blue oxidation product (oxTMB). The oxidation reaction was inhibited and led to a significant bleaching of the blue color in the presence of reducing substances isoniazid (INH) and ascorbic acid (AA). Based on these principles, we developed a colorimetric sensing platform for the detection of INH and AA, exhibiting good sensitivity and stability. This work provided a straightforward approach to the structural engineering of nanomaterials and the enhancement of enzyme-mimicking properties.

A Bimetallic Polymerization Network for Effective Increase in Labile Iron Pool and Robust Activation of cGAS/STING Induces Ferroptosis-Based Tumor Immunotherapy.

Due to the inherent low immunogenicity and immunosuppressive tumor microenvironment (TME) of malignant cancers, the clinical efficacy and application of tumor immunotherapy have been limited. Herein, a bimetallic drug-gene co-loading network (Cu/ZIF-8@U-104@siNFS1-HA) is developed that increased the intracellular labile iron pool (LIP) and enhanced the weakly acidic TME by co-suppressing the dual enzymatic activities of carbonic anhydrase IX (CA IX) and cysteine desulfurylase (NFS1), inducing a safe and efficient initial tumor immunogenic ferroptosis. During this process, Cu2+ is responsively released to deplete glutathione (GSH) and reduce the enzyme activity of glutathione peroxidase 4 (GPX4), achieving the co-inhibition of the three enzymes and further inducing lipid peroxidation (LPO). Additionally, the reactive oxygen species (ROS) storm in target cells promoted the generation of large numbers of double-stranded DNA breaks. The presence of Zn2+ substantially increased the expression of cGAS/STING, which cooperated with ferroptosis to strengthen the immunogenic cell death (ICD) response and remodel the immunosuppressive TME. In brief, Cu/ZIF-8@U-104@siNFS1-HA linked ferroptosis with immunotherapy through multiple pathways, including the increase in LIP, regulation of pH, depletion of GSH/GPX4, and activation of STING, effectively inhibiting cancer growth and metastasis.

Quorum sensing bacteria in microplastics epiphytic biofilms and their biological characteristics which potentially impact marine ecosystem.

Microplastics (MPs) have been shown to be a new type of pollutant in the oceans, with complex biofilms attached to their surfaces. Bacteria with quorum sensing (QS) systems are important participants in biofilms. Such bacteria can secrete and detect signal molecules. When a signal molecule reaches its threshold level, bacteria with QS systems can perform several biological functions, such as biofilm formation and antibiotic metabolite production. However, the ecological effects of QS bacteria in biofilm as MPs distribute globally with ocean currents are not to be elucidate yet. In this study, polypropylene and polyvinyl chloride were selected for on-site enrichment to acquire microplastics with biofilms. Eight culturable QS bacteria in the resulting biofilm were isolated by using biosensor assays, and their biodiversity was analyzed. The profiles of the N-acyl-homoserine lactones (AHLs) produced by these bacteria were analyzed by using thin-layer chromatography (TLC)-bioautography and gas chromatography and mass spectrometry (GC-MS). Biofilm-forming properties and several biological characteristics, such as bacteriostasis, algal inhibition, and dimethylsulfoniopropionate (DMSP) degradation, were explored along with QS quenching. Results showed that QS bacteria were mainly affiliated with class Alphaproteobacteria, particularly Rhodobacteraceae, followed by class Gammaproteobacteria. TLC-bioautography and GC-MS analyses revealed that seven AHLs, namely, C6-HSL, C8-HSL, 3-oxo-C6-HSL, 3-oxo-C8-HSL, 3-oxo-C10-HSL, and two unidentified AHLs were produced. The QS system equipped bacteria with strong biofilm-forming capacity and may contribute to the keystone roles of Rhodobacteraceae. In addition, QS bacteria may exacerbate the adverse environmental effects of MPs, such as inducing the misfeeding of planktons on MPs. This study elucidated the diversity of QS bacteria in MP-associated biofilms and provided a new perspective of the effect of key membrane-forming bacteria on the marine ecological environment.

Proximity hybridization induced bipedal DNA walker for label-free electrochemical detection of apolipoprotein A4 based on DNA meditated Ag nanoparticles growth.

Apolipoprotein A4 (Apo-A4) is considered as a prospective molecular biomarker for diagnosis of depression due to its neurosynaptic toxicity. Here, we propose a neighboring hybridization induced catalyzed hairpin assembly (CHA) driven bipedal DNA walker that mediates hybridization of Ag nanoparticles (Ag NPs) with DNA probes for highly sensitive electrochemical quantitative detection of Apo-A4. Driven by CHA, this bipedal DNA walker can spread all over the surface of the sensor, induce the HP1-HP2 double chain structure, make the surface of the sensor negatively charged, and adsorb a large number of Ag ions. After chemical reduction with hydroquinone, the Ag NPs formed provide signal tracers for electrochemical dissolution analysis of the target. The Ag NPs formed by chemical reduction of hydroquinone can provide signal traces for electrochemical stripping analysis of target thrombin. The linear range of this method is from 10 pg mL-1 to 1000 ng mL-1, and the detection limit is 5.1 pg mL-1. This enzyme-free and labeling detection method provides a new strategy for rapid clinical detection of Apo-A4 and accurate identification of depression.

A Chiral Nanocomplex for Multitarget Therapy to Alleviate Neuropathology and Rescue Alzheimer's Cognitive Deficits.

Alzheimer's disease (AD) is a severe neurodegenerative condition characterized by inflammation, beta-amyloid (Aß) plaques, and neurodegeneration, which currently lack effective treatments. Chiral nanomaterials have emerged as a promising option for treating neurodegenerative disorders due to their high biocompatibility, strong sustained release ability, and specific enantiomer selectivity. The development of a stimulus-responsive chiral nanomaterial, UiO-66-NH2 @l-MoS2 QDs@PA-Ni (MSP-U), for the treatment of AD is reported. MSP-U is found to stimulate neural stem cell (NSCs) differentiation, promote in situ hydrogen (H2 ) production, and clear Aß plaques. l-MoS2 QDs modified with l-Cysteine (l-Cys) effectively enhance the differentiation of NSCs into neurons through circularly polarized near-infrared radiation. Doped-phytic acid nickel (PA-Ni) improves the activity of l-MoS2 QDs in scavenging reactive oxygen species at the lesion site via photocatalytic H2 production. Loading l-MoS2 QDs with UiO-66 type metal oxide suppresses electron-hole recombination effect, thereby achieving rapid charge separation and improving transport of photogenerated electrons, leading to significantly improved H2 production efficiency. The photothermal effect of MSP-U also clears the generated Aß plaques. In vivo evaluations show that MSP-U improves spatial cognition and memory, suggesting a promising potential candidate for the treatment of AD using chiral nanomaterials.

Custom-Made Piezoelectric Solid Solution Material for Cancer Therapy.

Piezoelectric material-mediated sonodynamic therapy (SDT) has received considerable research interest in cancer therapy. However, the simple applications of conventional piezoelectric materials do not realize the full potential of piezoelectric materials in medicine. Therefore, the energy band structure of a piezoelectric material is modulated in this study to meet the actual requirement for cancer treatment. Herein, an elaborate PEGylated piezoelectric solid solution 0.7BiFeO3 -0.3BaTiO3 nanoparticles (P-BF-BT NPs) is synthesized, and the resultant particles achieve excellent piezoelectric properties and their band structure is tuned via band engineering. The tuned band structure of P-BF-BT NPs is energetically favorable for the synchronous production of superoxide radicals (•O2 - ) and oxygen (O2 ) self-supply via water splitting by the piezoelectric effect. Besides, the P-BF-BT NPs can initiate the Fenton reaction to generate hydroxyl radical (•OH), and thus, chemodynamic therapy (CDT) can be augmented by ultrasound. Detailed in vitro and in vivo research has verified the promising effects of multimodal imaging-guided P-BF-BT NP-mediated synergistic SDT/CDT by the piezo-Fenton process in hypoxic tumor elimination, accompanied by high therapeutic biosafety. The current demonstrates a novel strategy for designing and synthesizing "custom-made" piezoelectric materials for cancer therapy in the future.

Hyaluronic acid-covered piezoelectric nanocomposites as tumor microenvironment modulators for piezoelectric catalytic therapy of melanoma.

Increasing the formation of reactive oxygen species (ROS) and reducing the elimination of ROS are the two main objectives in the development of novel inorganic sonosensitizers for use in sonodynamic therapy (SDT). Therefore, BTO-Pd-MnO2-HA nanocomplexes with targeted tumor cells and degradable oxygen-producing shells were designed as piezoelectric sonosensitizers for enhancing SDT. The deposition of palladium particles (Pd NPs) leads to the formation of Schottky junctions, promoting the separation of electron-hole pairs and thereby increasing the efficiency of toxic ROS generation in SDT. The tumor microenvironment (TME) triggers the degradation of MnO2, and the released Mn2+ ions catalyze the generation of hydroxyl radicals (•OH) from H2O2 through a Fenton-like reaction. BTO-Pd-MnO2-HA can continuously consume glutathione (GSH) and generate O2, thereby improving the efficiency of SDT and chemodynamic therapy (CDT). A multistep enhanced SDT process mediated by the piezoelectric sonosensitizers BTO-Pd-MnO2-HA was designed, targeted by hyaluronic acid (HA), activated by decomposition in TME, and amplified by deposition of Pd. This procedure not only presents a new alternative for the improvement of sonosensitizers but also widens the application of piezoelectric nanomaterials in biomedicine.

Oxygen vacancy-enhanced catalytic activity of hyaluronic acid covered-biomineralization nanozyme for reactive oxygen species-augmented antitumor therapy.

Insufficient hydrogen peroxide content in tumor cells, unsuitable pH and low efficiency of commonly used metal catalysts severely affect the efficiency of chemodynamic therapy, resulting in unsatisfactory efficacy of chemodynamic therapy alone. For this purpose, we designed a composite nanoplatform capable of targeting tumors and selectively degrading in the tumor microenvironment (TME) to address these issues. In this work, we synthesized Au@Co3O4 nanozyme inspired by crystal defect engineering. The addition of Au determines the formation of oxygen vacancies, accelerates electron transfer, and enhances redox activity, thus significantly enhancing the superoxide dismutase (SOD)-like and catalase (CAT)-like catalytic activities of the nanozyme. Subsequently, we camouflaged the nanozyme using a biomineralized CaCO3 shell to avoid damage to normal tissues by the nanozyme while effectively encapsulating the photosensitizer IR820, and finally the tumor targeting ability of the nanoplatform was enhanced by the modification of hyaluronic acid. Under near-infrared (NIR) light irradiation, the Au@Co3O4@CaCO3/IR820@HA nanoplatform not only visualizes the treatment with multimodal imaging, but also plays a photothermal sensitizing role through various strategies, while enhancing the enzyme catalytic activity, cobalt ion-mediated chemodynamic therapy (CDT) and IR820-mediated photodynamic therapy (PDT), and achieving the synergistic enhancement of reactive oxygen species (ROS) generation.

DNAzyme-driven bipedal DNA walker triggered to hybridize silver nanoparticle probes for electrochemical detection of amyloid-ß oligomer.

Amyloid-ß oligomer has been considered as a promising molecular biomarker for the diagnosis of Alzheimer's disease due to their significant neural synapse toxicity. Therefore, it is essential to create an easy approach for the selective detection of Amyloid-ß oligomer that has high sensitivity and cheap cost. In this work, we developed an innovative enzyme-free electrochemical aptasensor based on the DNAzyme-driven DNA bipedal walker tactics for sensing Amyloid-ß oligomer. Bipedal DNA walkers demonstrate a wider walking region, better walking kinetics, and higher amplification effectiveness than typical DNA walkers. The Mg2+-dependent DNAzyme drove the DNA walker, and the binding-induced DNA walker can sequentially shear MBs and form MB fragment structure. Finally, the detection probes modified AgNPs hybridized with the MB fragment structure, resulting in the multiplication of AgNPs on the electrode surface. Electrochemical stripping of AgNPs was used to test the performance of the obtained electrochemical sensor. In particular, a low detection limit of 5.94 fM and a wide linear range of 0.01 pM-0.1 nM were attained. The detection of Amyloid-ß oligomer in human serum was then carried out using this bipedal DNA walker biosensor, which shown good selectivity and outstanding reproducibility, indicating its usefulness in bioanalysis.

An NIR-Driven Upconversion/C3N4/CoP Photocatalyst for Efficient Hydrogen Production by Inhibiting Electron-Hole Pair Recombination for Alzheimer's Disease Therapy.

Redox imbalance and abnormal amyloid protein (Aß) buildup are key factors in the etiology of Alzheimer's disease (AD). As an antioxidant, the hydrogen molecule (H2) has the potential to cure AD by specifically scavenging highly harmful reactive oxygen species (ROS) such as •OH. However, due to the low solubility of H2 (1.6 ppm), the traditional H2 administration pathway cannot easily achieve long-term and effective accumulation of H2 in the foci. Therefore, how to achieve the continuous release of H2 in situ is the key to improve the therapeutic effect on AD. As a corollary, we designed a rare earth ion doped g-C3N4 upconversion photocatalyst, which can respond to NIR and realize the continuous production of H2 by photocatalytic decomposition of H2O in biological tissue, which avoids the problem of the poor penetration of visible light. The introduction of CoP cocatalyst accelerates the separation and transfer of photogenerated electrons in g-C3N4, thus improving the photocatalytic activity of hydrogen evolution reaction. The morphology of the composite photocatalyst was shown by transmission electron microscopy, and the crystal structure was studied by X-ray diffractometry and Raman analysis. In addition, the ability of g-C3N4 to chelate metal ions and the photothermal properties of CoP can inhibit Aß and reduce the deposition of Aß in the brain. Efficient in situ hydrogen production therapy combined with multitarget synergism solves the problem of a poor therapeutic effect of a single target. In vivo studies have shown that UCNP@CoP@g-C3N4 can reduce Aß deposition, improve memory impairment, and reduce neuroinflammation in AD mice.

Trimer structures formed by target-triggered AuNPs self-assembly inducing electromagnetic hot spots for SERS-fluorescence dual-signal detection of intracellular miRNAs.

Accurate quantitative, in situ and temporal tracking imaging of tumor-associated miRNAs in living cells could provide a basis for cancer diagnosis and prognosis. In this strategy, a surface-enhanced Raman scattering (SERS)-fluorescence (FL) dual-spectral sensor (DSS) was constructed based on the nanoscale photophysical properties of AuNPs, mediated by functionalized DNA, to achieve rapid imaging of FL and accurate SERS quantification of intracellular miRNAs. The dual-spectrum sensor in the strategy is highly sensitive, specific and reproducibly stable. The LOD values of the dual spectra were 3.58 pM (SERS) as well as 11.8 pM (FL) with RSD values less than 2.69%. The bispectral sensor self-assembled into a trimer by the lapidation of Y-type DNA under the excitation of the target, generating a stable enhanced electric field coupling; and selected adenine located in the enhanced electric field as the reporter molecule, simplifying the labeling process and variables of the Raman reporter molecule, distinguishing it from other traditional methods. This strategy successfully achieved accurate tracking and quantification of miR-21 in cancer cells and showed good stability in the cells. The reported probes are potential tools for reliable monitoring of biomolecular dynamics in living cells.

DNAzyme-driven bipedal DNA walker for label-free and signal-on electrochemical detection of amyloid-ß oligomer.

As a common technique for detecting AßO, the enzyme-linked immunosorbent assay (ELISA) method is time-consuming, high in cost, and poor in stability. Therefore, it is necessary to develop a highly sensitive, method-simple and low-cost method for the selective detection of AßO. Here, we created a novel signal-on and label-free electrochemical aptamer sensor for the detection of AßO based on a DNAzyme-driven DNA bipedal walking strategy. Compared with common DNA walkers, bipedal DNA walkers exhibit larger walking areas and faster walking kinetics, and provide higher amplification efficiency. The DNAwalker is powered by an Mg2+-dependent DNAzyme, and the binding-induced DNAwalker continuously clamps the MB, unlocking several active G-quadruplex-forming sequences. These G-quadruplexes can be further combined by hemin to generate a G-quadruplex/heme complex, resulting in an amperometric signal, resulting in a broad proportional band from 0.1 pM to 1 nM and an excellent detection range of 46 fM. A bipedal DNA walker aptamer sensor can detect human serum AßO with remarkable specificity, high reproducibility and practical application value.

H2O2/NIR-sensitive "two-step" nano theranostic system based hollow mesoporous copper sulfide/hyaluronic acid/JWH133 as an optimally designed delivery system for multidimensional treatment of RA.

Cannabinoid receptors are widely distributed in many cells in Rheumatoid arthritis RA and strengthening factor to boost the development of RA diseases. Here, the hollow mesoporous copper sulfide (CuS) was used as the carrier skeleton and the cannabinoid type 2 (CB2) receptor agonist JWH133 was efficiently loaded inside of CuS through adsorption, then the outer layer was modified with hyaluronic acid (HA) to prevent the leakage of internal drugs. After the CuS-JWH133@HA nano carrier reached the target area, HA responsive cracked under RA microenvironment to realize the first step of accurate drug delivery of JWH133, and the thermally responsive CuS under near-infrared (NIR) promoted the release of internal drugs. Then, JWH133 specifically combined CB2 receptors on the surface of macrophage, synovial cells and osteoblasts to realize the second step of drug delivery. The inflammatory factors secreted by cells are significantly inhibited, and the activity of osteoblasts was significantly enhanced. Therapeutic effect by CuS-JWH133@HA of RA was well verified by decreasing levels of inflammation in vivo and improvement of inflamed and swollen joints of mice. The CuS-JWH133@HA nanocomposite showed satisfactory multidimensional therapeutic effect of RA in vitro and in vivo, which provided a novel idea for RA treatment.

Prospects for the next generation of artificial enzymes for ensuring the quality of chilled meat: Opportunities and challenges.

As living standards rise, the demand for high-quality chilled meat among consumers also grows. Researchers and enterprises have been interested in ensuring the quality of chilled meat in all links of the downstream industry. Nanozyme has shown the potential to address the aforementioned requirements. Reasons and approaches for the application of nanozymes in the freshness assessment or shelf life extension of chilled meat were discussed. The challenges for applying these nanozymes to ensure the quality of chilled meat were also summarized. Finally, this review examined the safety, regulatory status, and consumer attitudes toward nanozymes. This review revealed that the freshness assessment of chilled meat is closely related to mimicking the enzyme activities of nanozymes, whereas the shelf life changes of chilled meat are mostly dependent on the photothermal activities and pseudophotodynamic activities of nanozymes. In contrast, studies regarding the shelf life of chilled meat are more challenging to develop, as excessive heat or reactive oxygen species impair its quality. Notably, meat contains a complex matrix composition that may interact with the nanozyme, reducing its effectiveness. Nanopollution and mass manufacturing are additional obstacles that must be overcome. Therefore, it is vital to choose suitable approaches to ensure meat quality. Furthermore, the safety of nanozymes in meat applications still needs careful consideration owing to their widespread usage.

A Smart Nanoreactor Based on an O2-Economized Dual Energy Inhibition Strategy Armed with Dual Multi-stimuli-Responsive "Doorkeepers" for Enhanced CDT/PTT of Rheumatoid Arthritis.

Activated fibroblast-like synovial (FLS) cells are regarded as an important target for rheumatoid arthritis (RA) treatment via starvation therapy mediated by glucose oxidase (GOx). However, the hypoxic RA-FLS environment greatly reduces the oxidation process of glucose and leads to a poor therapeutic effect of the GOx-based starvation therapy. In this work, we designed a hollow mesoporous copper sulfide nanoparticles (CuS NPs)-based smart GOx/atovaquone (ATO) codelivery system (named as V-HAGC) targeting RA-FLS cells to realize a O2-economized dual energy inhibition strategy to solve the limitation of GOx-based starvation therapy. V-HAGC armed with dual multi-stimuli-responsive "doorkeepers" can guard drugs intelligently. Once under the stimulation of photothermal and acidic conditions at the targeted area, the dual intelligent responsive "doors" would orderly open to realize the controllable release of drugs. Besides, the efficacy of V-HAGC would be much improved by the additional chemodynamic therapy (CDT) and photothermal therapy (PTT) stimulated by CuS NPs. Meanwhile, the upregulated H2O2 and acid levels by starvation therapy would promote the Fenton-like reaction of CuS NPs under O2-economized dual energy inhibition, which could enhance the PTT and CDT efficacy as well. In vitro and in vivo evaluations revealed V-HAGC with much improved efficacy of this combination therapy for RA. In general, the smart V-HAGC based on the O2-economized dual energy inhibition strategy combined with enhanced CDT and PTT has the potential to be an alternative methodology in the treatment of RA.

Smart Programmable Scalable Dual-Mode Diagnostic Logic Nanoflare Strategy for Dual-Tumor Marker Detection.

Compared with the single-marker detection scheme, the detection of multiple targets in the complex cell and biological environment can obtain more reliable detection results. Herein, we detected miRNA-21 and APE1 in two modes, AND and OR, respectively, based on gold nanoflares and simple logic components. In both modes, DNAzyme and APE1 can get rich fluorescence recovery results by breaking the DNA strands from the gold nanorods (AuNRs) and unquenching under different conditions. In vivo and in vitro experiments suggest that both nanoflares exhibit excellent biocompatibility and make efficient and sensitive judgments on the two targets. This strategy emphasizes the reuse nature of enzymes, and a small amount of target can generate a large amount of fluorescent signal in the logic device, which greatly reduces the detection limit when monitoring low-abundance targets. Since the short-stranded DNA component of the detection device is simple in composition and easy to program its probe sequence, it can be expanded into a detection system for the detection of other sets of related markers, which increases its potential for clinical application.