Sensor Array-Enabled Identification of Drugs for Repolarization of Macrophages to Anti-Inflammatory Phenotypes.

Macrophages are key components of the innate immune system that have essential functions in physiological processes and diseases. The phenotypic plasticity of macrophages allows cells to be polarized into a multidimensional spectrum of phenotypes, broadly classed as pro-inflammatory (M1) and anti-inflammatory (M2) states. Repolarization of M1 to M2 phenotypes alters the immune response to ameliorate autoimmune and inflammation-associated diseases. Detection of this repolarization, however, is challenging to execute in high-throughput applications. In this work, we demonstrate the ability of a single polymer fabricated to provide a six-channel sensor array that can determine macrophage polarization phenotypes. This sensing platform provides a sensitive and high-throughput tool for detecting drug-induced M1-to-M2 repolarization, allowing the identification of new therapeutic leads for inflammatory diseases. The ability of this sensor array to discriminate different M2 subtypes induced by drugs can also improve the efficacy evaluation of anti-inflammatory drugs and avoid adverse effects.

Degradable ZnS-Supported Bioorthogonal Nanozymes with Enhanced Catalytic Activity for Intracellular Activation of Therapeutics.

Bioorthogonal catalysis using transition-metal catalysts (TMCs) provides a toolkit for the in situ generation of imaging and therapeutic agents in biological environments. Integrating TMCs with nanomaterials mimics key properties of natural enzymes, providing bioorthogonal "nanozymes". ZnS nanoparticles provide a platform for bioorthogonal nanozymes using ruthenium catalysts embedded in self-assembled monolayers on the particle surface. These nanozymes uncage allylated profluorophores and prodrugs. The ZnS core combines the non-toxicity and degradability with the enhancement of Ru catalysis through the release of thiolate surface ligands that accelerate the rate-determining step in the Ru-mediated deallylation catalytic cycle. The maximum rate of reaction (Vmax) increases ∼2.5-fold as compared to the non-degradable gold nanoparticle analogue. The therapeutic potential of these bioorthogonal nanozymes is demonstrated by activating a chemotherapy drug from an inactive prodrug with efficient killing of cancer cells.

Cell-Based Chemical Safety Assessment and Therapeutic Discovery Using Array-Based Sensors.

Synthetic chemicals are widely used in food, agriculture, and medicine, making chemical safety assessments necessary for environmental exposure. In addition, the rapid determination of chemical drug efficacy and safety is a key step in therapeutic discoveries. Cell-based screening methods are non-invasive as compared with animal studies. Cellular phenotypic changes can also provide more sensitive indicators of chemical effects than conventional cell viability. Array-based cell sensors can be engineered to maximize sensitivity to changes in cell phenotypes, lowering the threshold for detecting cellular responses under external stimuli. Overall, array-based sensing can provide a robust strategy for both cell-based chemical risk assessments and therapeutics discovery.

Nano Assessing Nano: Nanosensor-Enabled Detection of Cell Phenotypic Changes Identifies Nanoparticle Toxicological Effects at Ultra-Low Exposure Levels.

Industrial use of nanomaterials is rapidly increasing, making the effects of these materials on the environment and human health of critical concern. Standard nanotoxicity evaluation methods rely on detecting cell death or major dysfunction and will miss early signs of toxicity. In this work, the use of rapid and sensitive nanosensors that can efficiently detect subtle phenotypic changes on the cell surface following nanomaterial exposure is reported. Importantly, the method reveals significant phenotypic changes at dosages where other conventional methods show normal cellular activity. This approach holds promise in toxicological and pharmacological evaluations to ensure safer and better use of nanomaterials.

Signal multi-amplified electrochemical biosensor for voltammetric determination of tau-441 protein in biological samples using carbon nanomaterials and gold nanoparticles to hint dementia.

A signal multi-amplified electrochemical biosensor was fabricated for tau-441 protein, a dementia biomarker. It utilizes a carbon nanocomposite film modified gold electrode. The carbon nanocomposite film was composed of multi-walled carbon nanotubes (MWCNTs), reduced graphene oxide (rGO), and chitosan (CS). For the nanocomposite film, rGO improved the dispersibility of MWCNTs, and the effective surface area of MWCNTs was increased. On the other hand, MWCNTs also increased the interlayer spacing of rGO, resulting in a thinner rGO layer. MWCNTs-rGO had a better conductivity than that of MWCNTs and rGO due to the synergy effect. Biocompatible CS was employed for immobilization of the specific antibody. Tau-441 protein was modified with gold nanoparticles (AuNPs) for signal amplification again. The response of the electrochemical biosensor is linear in the range 0.5-80 fM (0.5, 1.5, 5, 10, 40, 80 fM) with a limit of detection (LOD) of 0.46 fM, using differential pulse voltammetry (DPV) in a potential range of - 100-500 mV. The biosensor was successfully applied to the analysis of serum samples of 14 normal people, 14 mild cognitive impairment (MCI) patients, and 14 dementia patients. Graphical abstract Schematic representation of signal multi-amplified electrochemical biosensor for determination of tau-441 protein in human serum.

Nanoparticles with intermediate hydrophobicity polarize macrophages to plaque-specific Mox phenotype via Nrf2 and HO-1 activation.

Mox macrophages were identified recently and are closely associated with atherosclerosis. Considering the potential health risks and the impact on macrophage modulation, this study investigated the Mox polarization of macrophages induced by nanoparticles (NPs) with tunable hydrophobicity. One nanoparticle (C4NP) with intermediate hydrophobicity efficiently upregulated the mRNA expression of Mox-related genes including HO-1, Srxn1, Txnrd1, Gsr, Vegf and Cox-2 through increased accumulation of Nrf2 at a nontoxic concentration in both resting and LPS-challenged macrophages. Additionally, C4NP impaired phagocytic capacity by 20% and significantly increased the secretion of cytokines, including TNFα, IL-6 and IL-10. Mechanistic studies indicated that intracellular reactive oxygen species (ROS) were elevated by 1.5-fold and 2.6-fold in resting and LPS-challenged macrophages respectively. Phosphorylated p62 was increased by 2.5-fold in resting macrophages and maintained a high level in LPS-challenged ones, both of which partially accounted for the significant accumulation of Nrf2 and HO-1. Notably, C4NP depolarized mitochondrial membrane potential by more than 50% and switched macrophages from oxidative phosphorylation-based aerobic metabolism to glycolysis for energy supply. Overall, this study reveals a novel molecular mechanism potentially involving ROS-Nrf2-p62 signaling in mediating macrophage Mox polarization, holding promise in ensuring safer and more efficient use of nanomaterials.

Polarization of macrophages to an anti-cancer phenotype through in situ uncaging of a TLR 7/8 agonist using bioorthogonal nanozymes.

Macrophages are plastic cells of the immune system that can be broadly classified as having pro-inflammatory (M1-like) or anti-inflammatory (M2-like) phenotypes. M2-like macrophages are often associated with cancers and can promote cancer growth and create an immune-suppressive tumor microenvironment. Repolarizing macrophages from M2-like to M1-like phenotype provides a crucial strategy for anticancer immunotherapy. Imiquimod is an FDA-approved small molecule that can polarize macrophages by activating toll-like receptor 7/8 (TLR 7/8) located inside lysosomes. However, the non-specific inflammation that results from the drug has limited its systemic application. To overcome this issue, we report the use of gold nanoparticle-based bioorthogonal nanozymes for the conversion of an inactive, imiquimod-based prodrug to an active compound for macrophage re-education from anti- to pro-inflammatory phenotypes. The nanozymes were delivered to macrophages through endocytosis, where they uncaged pro-imiquimod in situ. The generation of imiquimod resulted in the expression of pro-inflammatory cytokines. The re-educated M1-like macrophages feature enhanced phagocytosis of cancer cells, leading to efficient macrophage-based tumor cell killing.

Biodegradable nanoemulsion-based bioorthogonal nanocatalysts for intracellular generation of anticancer therapeutics.

Bioorthogonal catalysis mediated by transition metal catalysts (TMCs) provides controlled in situ activation of prodrugs through chemical reactions that do not interfere with cellular bioprocesses. The direct use of 'naked' TMCs in biological environments can have issues of solubility, deactivation, and toxicity. Here, we demonstrate the design and application of a biodegradable nanoemulsion-based scaffold stabilized by a cationic polymer that encapsulates a palladium-based TMC, generating bioorthogonal nanocatalyst "polyzymes". These nanocatalysts enhance the stability and catalytic activity of the TMCs while maintaining excellent mammalian cell biocompatibility. The therapeutic potential of these nanocatalysts was demonstrated through efficient activation of a non-toxic prodrug into an active chemotherapeutic drug, leading to efficient killing of cancer cells.

Identification of Proteins Using Supramolecular Gold Nanoparticle-Dye Sensor Arrays.

The rapid detection of proteins is very important in the early diagnosis of diseases. Gold nanoparticles (AuNPs) can be engineered to bind biomolecules efficiently and differentially. Cross-reactive sensor arrays have high sensitivity for sensing proteins using differential interactions between sensor elements and bioanalytes. A new sensor array was fabricated using surface-charged AuNPs with dyes supramolecularly encapsulated into the AuNP monolayer. The fluorescence of dyes is partially quenched by the AuNPs and can be restored or further quenched due to the differential interactions between AuNPs with proteins. This sensing system enables the discrimination of proteins in both buffer and human serum, providing a potential tool for real-world disease diagnostics.

Electrochemical signal amplification strategy based on trace metal ion modified WS2 for ultra-sensitive detection of miRNA-21.

Previous researches have suggested the potential correlation between the development of breast cancer and the concentration of miRNA-21 in serum. Theoretically the doping of multivalent metal ions in WS2 could bring higher electron transfer capacity, but this hasn't been proven. To fill this research gap, through one-pot method we prepared seven nanocomposite structures modified with different metal ions (Co2+, Ni2+, Mn2+, Zn2+, Fe3+, Cr3+, La3+). Characterization revealed that ammonia produced by hydrothermal urea exfoliated the multilayer graphene oxide (MGO) and provided a nitrogen source for doping reduction to form a 3D flower-like structure (NrGOF) with high specific surface area. Meanwhile, the modification of WS2 by Fe3+ not only enhanced its electrochemical conductivity but also gave the material an additional peroxidase activity centre. In the composite Fe3+-WS2/NrGOF-AgNPs, NrGOF is used as a conductive loading interface for WS2, while Fe3+ served as the catalytic and electron transfer centre for secondary amplification of the electrochemical signal. The experimental results showed that the sensing platform has a low limit of detection (LOD) of 1.18 aM for miRNA-21 in the concentration range of 10-17-10-12 M and has been successfully applied to the detection of real serum samples.

Antimicrobial polymer-loaded hydrogels for the topical treatment of multidrug-resistant wound biofilm infections.

Integration of antimicrobial polymeric nanoparticles into hydrogel materials presents a promising strategy to address multidrug-resistant biofilm infections. Here we report an injectable hydrogel loaded with engineered cationic antimicrobial polymeric nanoparticles (PNPs) for the effective topical treatment of severe wound biofilm infections. The PNPs demonstrated biofilm penetration and disruption, resulting in the eradication of resistant and persister cells that reside within the biofilm. Significantly, PNPs did not elicit resistance development even after multiple exposures to sub-therapeutic doses. In vitro studies showed PNPs significantly reduced prolonged inflammation due to infection and promoted fibroblast migration. These PNPs were then incorporated into Poloxamer 407 (P407) hydrogels and utilized as an inert carrier for PNPs to provide a controlled and sustained topical release of the antimicrobial nanoparticles at the wound area. In vivo studies using a mature (4-day) wound biofilm infection in a murine model mimicking severe human wound infections demonstrated provided 99% bacterial biofilm clearance and significantly enhanced wound healing. Overall, this work demonstrated the efficacy and selectivity of the antimicrobial polymer-loaded hydrogel platform as a topical treatment for difficult-to-treat wound biofilm infections.

Synergistic Treatment of Multidrug-Resistant Bacterial Biofilms Using Silver Nanoclusters Incorporated into Biodegradable Nanoemulsions.

Multidrug resistance (MDR) in bacteria is a critical global health challenge that is exacerbated by the ability of bacteria to form biofilms. We report a combination therapy for biofilm infections that integrates silver nanoclusters (AgNCs) into polymeric biodegradable nanoemulsions (BNEs) incorporating eugenol. These Ag-BNEs demonstrated synergistic antimicrobial activity between the AgNCs and the BNEs. Microscopy studies demonstrated that Ag-BNEs penetrated the dense biofilm matrix and effectively disrupted the bacterial membrane. The Ag-BNE vehicle also resulted in more effective silver delivery into the biofilm than AgNCs alone. This combinacional system featured disruptionof biofilms by BNEs and enhanced delivery of AgNCs for synergy to provide highly efficient killing of MDR biofilms.

Integration of Antimicrobials and Delivery Systems: Synergistic Antibiofilm Activity with Biodegradable Nanoemulsions Incorporating Pseudopyronine Analogs.

Multi-drug-resistant (MDR) bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), pose a significant challenge in healthcare settings. Small molecule antimicrobials (SMAs) such as α-pyrones have shown promise as alternative treatments for MDR infections. However, the hydrophobic nature of many SMAs limits their solubility and efficacy in complex biological environments. In this study, we encapsulated pseudopyronine analogs (PAs) in biodegradable polymer nanoemulsions (BNEs) for efficient eradication of biofilms. We evaluated a series of PAs with varied alkyl chain lengths and examined their antimicrobial activity against Gram-positive pathogens (S. aureus, MRSA, and B. subtilis). The selected PA with the most potent antibiofilm activity was incorporated into BNEs for enhanced solubility and penetration into the EPS matrix (PA-BNEs). The antimicrobial efficacy of PA-BNEs was assessed against biofilms of Gram-positive strains. The BNEs facilitated the solubilization and effective delivery of the PA deep into the biofilm matrix, addressing the limitations of hydrophobic SMAs. Our findings demonstrated that the PA2 exhibited synergistic antibiofilm activity when it was loaded into nanoemulsions. This study presents a promising platform for addressing MDR infections by combining pseudopyronine analogs with antimicrobial biodegradable nanoemulsions, overcoming challenges associated with treating biofilm infections.

An array-based nanosensor for detecting cellular responses in macrophages induced by femtomolar levels of pesticides.

Environmental agents can induce cellular responses at concentrations far below the limits of detection for current viability and biomarker-based cell sensing platforms. Hypothesis-free cell sensor platforms can be engineered to maximize sensitivity to phenotypic changes, providing a tool for lowering the threshold for detecting cellular changes. Pesticides are one of the most prevalent sources of chemical exposure due to their use in food and agriculture fields. We report here a FRET-based nanosensor array engineered to maximize responses to changes at cell surfaces after pesticide exposure. This sensor array robustly detected macrophage responses to femtomolar concentrations of common pesticides-orders of magnitude lower concentrations than traditional toxicological and biomarker-based strategies. Significantly, this platform was able to classify these responses by pesticide class, demonstrating the ability to distinguish between changes induced by these different agents. Taken together, hypothesis-free cell surface sensing is a promising tool for detecting the effects of ultra-trace environmental chemicals on human health, as well as detecting threshold responses for use in drug discovery and diagnostics.

Visualizing the Spatial Distribution of Arctium lappa L. Root Components by MALDI-TOF Mass Spectrometry Imaging.

This study is aimed at developing novel analytical methods to accurately visualize the spatial distribution of various endogenous components in Arctium lappa L. (A. lappa) roots, and to precisely guide the setting of pre-treatment operations during processing technologies and understand plant metabolism process. The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) imaging technology was used for visual demonstration of the in situ spatial distribution in A. lappa roots. This work consisted of four steps: matrix selection, section preparation, matrix coating, and MALDI-TOF MS imaging analysis. Consequently, eight saccharides, four caffeoylquinic acids, four flavonoids, six amino acids, one choline, and one phospholipid were imaged and four unidentified components were found. Saccharides were distributed in the center, whereas caffeoylquinic acids and flavonoids were mainly present in the epidermis and cortex. Furthermore, amino acids were mainly detected in the phloem, and choline in the cambium, while phosphatidylserine was found in the secondary phloem and cambium. This study demonstrated that MALDI-TOF MS imaging technology could provide a technical support to understand the spatial distribution of components in A. lappa roots, which would promote the processing technologies for A. lappa roots and help us to understand the plant metabolism process.

Direct discrimination of cell surface glycosylation signatures using a single pH-responsive boronic acid-functionalized polymer.

Cell surface glycans serve fundamental roles in many biological processes, including cell-cell interaction, pathogen infection, and cancer metastasis. Cancer cell surface have alternative glycosylation to healthy cells, making these changes useful hallmarks of cancer. However, the diversity of glycan structures makes glycosylation profiling very challenging, with glycan 'fingerprints' providing an important tool for assessing cell state. In this work, we utilized the pH-responsive differential binding of boronic acid (BA) moieties with cell surface glycans to generate a high-content six-channel BA-based sensor array that uses a single polymer to distinguish mammalian cell types. This sensing platform provided efficient discrimination of cancer cells and readily discriminated between Chinese hamster ovary (CHO) glycomutants, providing evidence that discrimination is glycan-driven. The BA-functionalized polymer sensor array is readily scalable, providing access to new diagnostic and therapeutic strategies for cell surface glycosylation-associated diseases.

Fluorescence assay for three organophosphorus pesticides in agricultural products based on Magnetic-Assisted fluorescence labeling aptamer probe.

There has been increasing recent concern about the agricultural use of organophosphorus pesticides. A rapid and sensitive fluorescence assay for the detection of three organophosphorus pesticides has therefore been developed using 6-carboxy-fluorescein labeling aptamer as the probe and functionalized magnetic nanoparticles as the separation carrier. The aptamer hybridized with complementary DNA conjugated on the surface of the magnetic nanoparticles to form a magnetic aptamer-complementary DNA complex. Upon introducing the target organophosphorus pesticide, the aptamer departed from the complementary DNA, resulting in the fluorescence signal. Under optimized conditions, the limits of detection (LODs, S/N = 3) for trichlorfon, glyphosate, and malathion were 72.20 ng L-1, 88.80 ng L-1, and 195.37 ng L-1, respectively. The method was applied for the detection of trichlorfon, glyphosate, and malathion in spiked lettuce and carrot samples. The recoveries were in the range of 79.4%-118.7%, which were in good agreement with those obtained by gas chromatography, and the relative standard deviations were also acceptable. The method therefore has high sensitivity, so provides a means for the detection of multiple organophosphorus pesticides.

Development of direct competitive biomimetic immunosorbent assay based on quantum dot label for determination of trichlorfon residues in vegetables.

A direct competitive biomimetic immunosorbent assay method based on molecularly imprinted polymer was developed for the determination of trichlorfon. A CdSe/ZnS quantum dot label was used as the marker. The hydrophilic imprinted film was synthesized directly on the surface of a 96-well plate, and characterized by Fourier-transform infrared spectroscopy and thermo-gravimetric analyses. The method exhibited high stability, selectivity, and sensitivity. Under optimal conditions, the limits of detection and sensitivity of the biomimetic immunosorbent assay method were 9.0 µg L-1 and 5.0 mg L-1 (0.1 mg kg-1 and 62.5 mg kg-1 for vegetable sample), respectively. Low cross-reactivity values of 19.2% and 15.6% were obtained for the structural analogues. Spinach and rape samples spiked with trichlorfon were extracted and determined by this method with recoveries ranging from 83.6% to 91.1%. The method was applied for the detection of trichlorfon residues in leek and cucumber samples, and results correlated well with those obtained using GC.

Drug induces depression-like phenotypes and alters gene expression profiles in Drosophila.

BACKGROUND: Major depressive disorder (MDD) is a severe mental illness that affects more than 350 million people worldwide. However, the molecular mechanisms of depression are currently unclear. Studies suggest that Drosophila and humans have similar depression-like symptoms under pressure. In this research, we choose Drosophila melanogaster as the animal model to explore the molecular mechanisms that trigger depression. RESULTS: We found that feeding D. melanogaster with the medium containing Levodopa or Chlorpromazine could induce depression-like phenotypes in both behavioral and biochemical biomarkers, including significantly decreased food intake, mating frequency, serotonin (5-HT) concentration, and increased malondialdehyde (MDA) concentration as well as reduced activity of superoxide dismutase (SOD). Moreover, the progeny of Chlorpromazine-treated flies also showed these depression-like features. By RNA-seq technology, we identified 467 genes that were differentially expressed between Chlorpromazine treated (CPZ) and control male flies [fold-change of ≥2 (q-value<5%)]. When comparing CPZ with control flies, 312 genes were upregulated and 155 genes downregulated. Differential expression of genes related to metabolic pathway, Parkinson's disease, Huntington's disease, Alzheimer's disease and lysozyme pathways were observed. Quantitative reverse transcriptase PCR (qRT-PCR) confirmed that 19 genes are differentially expressed in CPZ and control male flies. CONCLUSIONS: Levodopa, or Chlorpromazine can induce depression-like phenotypes in D. melanogaster regarding changes of appetite and sexual activity, and some key biochemical markers. A total of 467 genes were identified by RNA-seq analysis to have at least a 2-fold-change in expression between CPZ and control flies, including genes involved in metabolism, neurological diseases and lysozyme pathways. Our data provide additional insight into molecular mechanisms underlying depressive disorders in humans and may also contribute to clinical treatment.

Comorbidity between depression and asthma via immune-inflammatory pathways: a meta-analysis.

BACKGROUND: Depression is often present in patients with asthma and vice versa. In this review, we aimed to summarize reports on the comorbidity of depression and asthma, and to seek evidence that the biological mechanisms of allergy may have an important role linking asthma and depression. METHOD: To explore the relationship and pathway underpinning this comorbidity, we reviewed medical articles and undertook a meta-analysis of epidemiological studies on (i) incidence of asthma in patients with depression; (ii) morbidity of depression in patients with asthma; (iii) concentration of cytokines in depressed subjects. RESULTS: High level of comorbidity of asthma and depression was consistently demonstrated in 10 studies of patients with asthma and four studies of patients with depression. In search of biological connection of the two illnesses, thirty-eight studies were included for Meta-analyses examining differences in allergy related cytokines between patients with depression and non-depressive subjects. In people with depression, concentration of monocytes related cytokines such as IL-1 (1.56ng/mL, 95% CI: 0.00-3.12, p=0.05) was significantly higher than that in non-depressive control subjects. At the same time, some other inflammatory factors including IL-4 (5.77pg/mL, 95% CI: 2.34-9.21, p=0.00010), IL-6 (1.44ng/mL, 95% CI: 1.05-1.82, p<0.00001) and TNF-α(3.01ng/mL, 95% CI: 1.76-4.26, p<0.00001) were extremely significantly higher in depressed people compared with the controls. There was no significant differences of the T cell related cytokine levels, IFN-γ (-0.16ng/mL, 95% CI: -0.85-7.73, p=0.97), accompanied with IL-10 (0.67ng/mL, 95% CI: -0.84-2.18, p=0.38) between depressive and non-depressive groups. CONCLUSIONS: The varying levels of certain cytokines play an important role in arousing and remitting asthma and depression. That suggests inflammatory response could be a common pathway adjusting both depression and asthma.