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The development of fluorescent iron oxide nanomaterials is highly desired for multimodal molecular imaging. Instead of incorporating fluorescent dyes on the surface of iron oxides, a ligand-assisted synthesis approach is developed to allow near-infrared (NIR) fluorescence in Fe3O4 nanostructures. Using a trimesic acid (TMA)/citrate-mediated synthesis, fabricated Fe3O4 nanostructures can generate a NIR two-photon florescence (TPF) peak around 700 nm under the excitation by a 1230-nm femtosecond laser. By tailoring the absorption of Fe3O4 nanostructures toward NIR band, the NIR-TPF efficiency can be greatly increased. Through internal etching, surface peeling, and ligand replacement, spectroscopic results validated that such resonantly enhanced NIR-TPF is mediated by surface states with strong NIR-IR absorption. This TPF signal evolution can be generalized to other iron oxide nanomaterials like magnetite nanoparticles and α-Fe2O3 nanoplates. Using the developed fluorescent Fe3O4 nanostructures, it is demonstrated that their TPF and third harmonic generation (THG) contrast in the nonlinear optical microscopy of live cells. It is anticipated that the synthesized NIR photofunctional Fe3O4 will serve as a versatile platform for dual-modality magnetic resonance imaging (MRI) as well as a magnet-guided theranostic agent. [ABSTRACT FROM AUTHOR]

T24 cells cotreated with (b) Au@TNA@MB NPs and (c) folic acid (FA)-conjugated Au@TNA@MB NPs for 0.75-4 h upon excitation at 650 nm. Photodynamic therapy (PDT) treatment of T24 cells stained with DCFH-DA dye by using (d) Au@TNA@MB NPs and (e) FA-conjugated Au@TNA@MB NPs. Development of Folic Acid-Conjugated and Methylene Blue-Adsorbed Au@TNA Nanoparticles for Enhanced Photodynamic Therapy of Bladder Cancer Cells. [Extracted from the article]

Staphylococcus aureus (S. aureus) forms biofilm that causes periprosthetic joint infections and osteomyelitis (OM) which are the intractable health problems in clinics. The silver-containing nanoparticles (AgNPs) are antibacterial nanomaterials with less cytotoxicity than the classic Ag compounds. Likewise, gold nanoparticles (AuNPs) have also been demonstrated as excellent nanomaterials for medical applications. Previous studies have showed that both AgNPs and AuNPs have anti-microbial or anti-inflammatory properties. We have developed a novel green chemistry that could generate the AuAg nanocomposites, through the reduction of tannic acid (TNA). The bioactivity of the nanocomposites was investigated in S. aureus biofilm-exposed human osteoblast cells (hFOB1.19). The current synthesis method is a simple, low-cost, eco-friendly, and green chemistry approach. Our results showed that the AuAg nanocomposites were biocompatible with low cell toxicity, and did not induce cell apoptosis nor necrosis in hFOB1.19 cells. Moreover, AuAg nanocomposites could effectively inhibited the accumulation of reactive oxygen species (ROS) in mitochondria and in rest of cellular compartments after exposing to bacterial biofilm (by reducing 0.78, 0.77-fold in the cell and mitochondria, respectively). AuAg nanocomposites also suppressed ROS-triggered inflammatory protein expression via MAPKs and Akt pathways. The current data suggest that AuAg nanocomposites have the potential to be a good therapeutic agent in treating inflammation in bacteria-infected bone diseases. [ABSTRACT FROM AUTHOR]

Herein, we present a one-pot hydrothermal approach for synthesizing metal–organic framework-derived copper (II) benzene-1,3,5-tricarboxylate (Cu-BTC) nanowires (NWs) using dopamine as the reducing agent and precursor for a polydopamine (PDA) surface coating formation. In addition, PDA can act as a PTT agent and enhance NIR absorption, producing photothermal effects on cancer cells. These NWs displayed a photothermal conversion efficiency of 13.32% after PDA coating and exhibited good photothermal stability. Moreover, NWs with a suitable T1 relaxivity coefficient (r1 = 3.01 mg−1 s−1) can be effectively used as magnetic resonance imaging (MRI) contrast agents. By increasing concentrations, cellular uptake studies showed a greater uptake of Cu-BTC@PDA NWs into cancer cells. Further, in vitro studies showed PDA-coated Cu-BTC NWs possess exceptional therapeutic performance by 808 nm laser irradiation, destroying 58% of cancer cells compared with the absence of laser irradiation. This promising performance is anticipated to advance the research and implementation of copper-based NWs as theranostic agents for cancer treatment. [ABSTRACT FROM AUTHOR]

While significant progress has been made to clarify the effects of Au and Ag nanoparticle size on SERS enhancement, research on the size effects of copper nanoparticles and copper-related nanoalloys on SERS enhancement remain scarce. Nanoscale copper (Cu) is important because of its unique sensing and catalytic properties; however, research on its size and compositional effects remains a significant challenge because of the intricate fabrication process and difficulty in preventing oxidation. Our study elucidated the size-dependent, surface-enhanced Raman scattering (SERS) of Cu NPs, particularly the sensing capabilities of both electromagnetic (EM) SERS at 1.5 × 103 and chemical enhancement (CE) SERS at 3.6 × 104 of approximately 58 nm Cu NPs. Additionally, a solution aging examination revealed preservation of the metal-related core structure, surface plasmon resonance, and SERS features of the PSMA/ONPG-coated Cu NPs for up to 7 days. With the introduction of galvanic replacement reactions and laser ablation syntheses, the incorporation of Au atoms enabled the fabrication of 7–75 nm Au x Cu y nanoparticles by using the remaining Cu core after aging in water, which offered precise control over the Cu/Au ratio from 5/95 to 29/71. SERS measurements of the large Au x Cu y nanoparticles amplified up to 1.4 × 104 of the EM-mediated vibrational signals from the adsorbed molecules. The strong Au–S chemical bonds of the Au-rich Au x Cu y nanocrystals increased the CE SERS to 5.5 × 104, whereas the Au 3 Cu 1 crystals at the Au x Cu y interface decreased the CE SERS but improved the electron transfer for catalysis via SERS detection. Our research provides further insight into the structural and size effects of Cu and AuCu alloys used as SERS enhancers and offers avenues for designing cutting-edge SERS catalytic sensors tailored to Cu-related catalytic reactive structures. For the first time, we also manipulated the Cu atomic structure and surface composition to understand the significance of surface effects on SERS substrates of the Cu series from a nanoscale analytical perspective. This study designed a wet chemistry approach and its combination with laser ablation to synthesize 13–75 nm copper nanoparticles and 7–75 nm Au x Cu y nanoparticles. The surface-enhanced Raman scattering effect and interfacial catalysis of Cu-based nanomaterials were investigated in terms of their size/surface properties' electromagnetic and chemical field enhancements. [Display omitted] • Highly stable and size-tunable Cu nanoparticles synthesized via combined aging reactions. • With significant improvements on SERS at approximately 58 nm of Cu nanoparticles for up to 7 days. • Galvanic replacement/laser ablation syntheses to fabricate Au x Cu y nanoparticles for size-dependent SERS enhancement. • Au-rich surface of AuCu nanomaterials provides appropriate chemical effect-SERS functionality. • Interfacial catalysis with ∼30 % Au 3 Cu 1 crystals facilitated the efficient hydrogenation from 4-NTP to 4-ATP. [ABSTRACT FROM AUTHOR]

Nanoparticles are widely used in biomedical applications and cancer treatments due to their minute scale, multi-function, and long retention time. Among the various nanoparticles, the unique optical property derived from the localized surface plasmon resonance effect of metallic nanoparticles is a primary reason that metallic nanoparticles are researched and applied. Copper and Iron nanoparticles have the potential to generate hydroxyl radicals in excess H2O2 via Fenton or Fenton-like reactions. On the other hand, gold nanoparticles equipped with a photosensitizer can transfer the energy of photons to chemical energy and enhance the production of singlet oxygen, which is suitable for cancer treatment. With the actions of these two reactive oxygen species in the tumor microenvironment, cell apoptosis can further be induced. In this work, we first synthesized dual metal nanoparticles with poly[styrene-alt-(maleic acid, sodium salt)(Cu ferrite oxide-polymer) by a simple one-step hydrothermal reduction reaction. Then, gold(III) was reduced and doped into the structure, which formed a triple metal structure, Au-doped Cu ferrite nanoparticles (Au/Cu ferrite oxide-polymer NPs). The metal ratio of the product could be controlled by manipulating the Fe/Cu ratio of reactants and the sequence of addition of reactants. The core–shell structure was verified by transmission electron microscopy. Moreover, the hydroxyl radical and singlet oxygen generation ability of Au/Cu ferrite oxide-polymer was proved. The chemodynamic and photodynamic effect was measured, and the in vitro ROS generation was observed. Furthermore, the behavior of endocytosis by cancer cells could be controlled by the magnetic field. The result indicated that Au/Cu ferrite oxide-polymer core–shell nanoreactor is a potential agent for chemodynamic/photodynamic synergetic therapy. [ABSTRACT FROM AUTHOR]

Nanosilver is a versatile biomedical agent that can potentially battle against bacterial infection. Herein, we introduce an energy-efficient green approach to synthesize phytonutrient modified silver nanoparticles (AgNPs) using the cogon grass extract (CGE) in 15 minutes. The biogenic AgNPs were characterized using UV-Vis, FT-IR, TEM, XRD, XPS, and zeta-potential measurements. The results from in vitro biological assays indicated that CGE-mediated AgNPs possess good antioxidant activity, broad-spectrum antibacterial activity, satisfactory dispersion stability, and trivial hemolytic activity. Among the reported biogenic AgNP studies, AgNPs synthesized using the CGE displayed a superior antibacterial performance against two drug-resistant Acinetobacter baumannii strains and showed stronger bactericidal capability toward E. coli and S. aureus. Investigation of the antibacterial mechanism of CGE-mediated AgNPs toward bacteria indicated the accumulation of AgNPs in the bacterial cells, steady release of silver ions, and production of reactive oxygen species to damage the bacterial surface structure. Additionally, our mass spectrometric screening revealed that several putative phytochemicals in the CGE act as the reducing agent capping on the AgNP surfaces, which intensifies the antibacterial activity. These data indicate that the CGE-mediated AgNPs can act as a broad-spectrum antibacterial agent in public health. [ABSTRACT FROM AUTHOR]

The escape of bladder cancer from immunosurveillance causes monotherapy to exhibit poor efficacy; therefore, designing a multifunctional nanoparticle that boosts programmed cell death and immunoactivation has potential as a treatment strategy. Herein, we developed a facile one-pot coprecipitation reaction to fabricate cluster-structured nanoparticles (CNPs) assembled from Fe3O4 and iron chlorophyll (Chl/Fe) photosensitizers. This nanoassembled CNP, as a multifunctional theranostic agent, could perform red-NIR fluorescence and change the redox balance by the photoinduction of reactive oxygen species (ROS) and attenuate iron-mediated lipid peroxidation by the induction of a Fenton-like reaction. The intravesical instillation of Fe3O4@Chl/Fe CNPs modified with 4-carboxyphenylboronic acid (CPBA) may target the BC wall through glycoproteins in the BC cavity, allowing local killing of cancer cells by photodynamic therapy (PDT)-induced singlet oxygen and causing chemodynamic therapy (CDT)-mediated ferroptosis. An interesting possibility is reprogramming of the tumor microenvironment from immunosuppressive to immunostimulatory after PDT-CDT treatment, which was demonstrated by the reduction of PD-L1 (lower "off" signal to the effector immune cells), IDO-1, TGF-β, and M2-like macrophages and the induction of CD8+ T cells on BC sections. Moreover, the intravesical instillation of Fe3O4@Chl/Fe CNPs may enhance the large-area distribution on the BC wall, improving antitumor efficacy and increasing survival rates from 0 to 91.7%. Our theranostic CNPs not only demonstrated combined PDT-CDT-induced cytotoxicity, ROS production, and ferroptosis to facilitate treatment efficacy but also opened up new horizons for eliminating the immunosuppressive effect by simultaneous PDT-CDT. [ABSTRACT FROM AUTHOR]

Dye Sensitized Solar Cells (DSSC) possess huge potential in solar energy utilisation. Immense research has been carried out in order to improve its performance. This paper suggests an alternative way of employing Light Trapping technique on DSSC by dry etching substrates before depositing the transparent conductive oxide (TCO) layer on one of the electrodes. The result demonstrated a decrease in reflectance before depositing the TCO, but an increase in reflectance after depositing the TCO. Texturing might also help to increase the effective surface area at the interface between various cell layers, providing a shorter path for the electron transport layer and improving collection efficiencies. [ABSTRACT FROM AUTHOR]

Fraction 5 was chromatographed with Si column chromatography (CC) using I n i -hexane-EtOAc-acetone (from 100% I n i -hexane to 100% acetone) to obtain subfractions 5A-5K. Subfraction 5D was separated by NP-HPLC using a mixture of I n i -hexane-acetone (50:1) to yield B 1 b (11.9 mg). Subfraction 5E was separated by NP-HPLC using a mixture of I n i -hexane-acetone (5:1) to yield B 4 b (23.1 mg). Fraction 10 was chromatographed with Si CC using I n i -hexane-EtOAc-acetone (from 100% I n i -hexane to 100% acetone) to obtain subfractions 10A-10L. Subfraction 10H8 was separated by NP-HPLC using a mixture of I n i -hexane-acetone (3:1) to yield B 6 b (22.0 mg) and B 7 b (1.3 mg). [Extracted from the article]

Fraction F was chromatographed with Si CC using a mixture of I n i -hexane-acetone (6:1) to yield B 4 b (26.6 mg). Fraction I3 was separated by NP-HPLC using a mixture of I n i -hexane-acetone (17:3) to yield B 8 b (0.7 mg). Fraction G was chromatographed with Si CC using I n i -hexane-EtOAc-acetone-MeOH (from 100% I n i -hexane to 100% MeOH) to obtain fractions G1-G15. Fraction K was chromatographed with Si CC using a mixture of I n i -hexane-acetone (3:1) to yield B 2 b (123.1 mg). [Extracted from the article]

Due to the enormous demand for clean energy generation and for efficient energy storage, developing green and storable energy has become an urgent task. This subject, thus, stimulates studies on the improvement of new electrocatalysts. Specifically, through improving the population of active sites and/or the activity of individual sites, the performance of the catalysts can be significantly improved. However, clarifying the contribution of these two factors is still ambiguous and must be done with great care. To allow researchers in related fields to present their findings objectively, having a clear insight into the electrocatalytic activity is indispensable. In this study, a series of cobalt‐based pre‐electrocatalysts are taken as an example to examine their corresponding oxygen evolution reaction (OER) behaviors. Wherein, the three important metrics – electrochemical active surface area (ECSA)/roughness factor (RF), Tafel slope, and turnover frequency (TOF) – are used to profile the population of active sites of electrocatalysts and the activity of related individual sites. The results indicate the correction of OER behavior by ECSA/RF manifests the more accurate identification of OER activity. Meanwhile, the timing to obtain RF/ECSA significantly influence such an evaluation. Altogether, a fair benchmarking is proposed for the comparison between the activities of electrocatalysts. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is a promising treatment for malignancy. However, the low molecular solubility of photosensitizers (PSs) with a low accumulation at borderline malignant potential lesions results in the tardy and ineffective management of recurrent urothelial carcinoma. Herein, we used tannic acid (TNA), a green precursor, to reduce HAuCl4 in order to generate Au@TNA core-shell nanoparticles. The photosensitizer methylene blue (MB) was subsequently adsorbed onto the surface of the Au@TNA nanoparticles, leading to the incorporation of a PS within the organic shell of the Au nanoparticle nanosupport, denoted as Au@TNA@MB nanoparticles (NPs). By modifying the surface of the Au@TNA@MB NPs with the ligand folate acid (FA) using NH2-PEG-NH2 as a linker, we demonstrated that the targeted delivery strategy achieved a high accumulation of PSs in cancer cells. The cell viability of T24 cells decreased to 87.1%, 57.1%, and 26.6% upon treatment with 10 ppm[Au] Au@TNA/MB NPs after 45 min, 2 h, and 4 h of incubation, respectively. We also applied the same targeted PDT treatment to normal urothelial SV-HUC-1 cells and observed minor phototoxicity, indicating that this safe photomedicine shows promise for applications aiming to achieve the local depletion of cancer sites without side effects. [ABSTRACT FROM AUTHOR]

Nanotechnology has rapidly promoted the development of a new generation of industrial and commercial products; however, it has also raised some concerns about human health and safety. To evaluate the toxicity of the great diversity of nanomaterials (NMs) in the traditional manner, a tremendous number of safety assessments and a very large number of animals would be required. For this reason, it is necessary to consider the use of alternative testing strategies or methods that reduce, refine, or replace (3Rs) the use of animals for assessing the toxicity of NMs. Autophagy is considered an early indicator of NM interactions with cells and has been recently recognized as an important form of cell death in nanoparticle-induced toxicity. Impairment of autophagy is related to the accelerated pathogenesis of diseases. By using mechanism-based high-throughput screening in vitro, we can predict the NMs that may lead to the generation of disease outcomes in vivo. Thus, a tiered testing strategy is suggested that includes a set of standardized assays in relevant human cell lines followed by critical validation studies carried out in animals or whole organism models such as C. elegans (Caenorhabditis elegans), zebrafish (Danio rerio), and Drosophila (Drosophila melanogaster)for improved screening of NM safety. A thorough understanding of the mechanisms by which NMs perturb biological systems, including autophagy induction, is critical for a more comprehensive elucidation of nanotoxicity. A more profound understanding of toxicity mechanisms will also facilitate the development of prevention and intervention policies against adverse outcomes induced by NMs. The development of a tiered testing strategy for NM hazard assessment not only promotes a more widespread adoption of non-rodent or 3R principles but also makes nanotoxicology testing more ethical, relevant, and cost- and time-efficient. [ABSTRACT FROM AUTHOR]

[Display omitted] • Citric acid (CA)-modified cellulose materials (CMCF and CMRC) were fabricated by a green dip-coating approach. • CA-modified cellulose materials show superhydrophilicity and underwater superoleophobicity. • The CMCF exhibits excellent separation performance for oil/water mixtures. • The compressed CMRC can separate emulsions and dye-containing wastewater. • CMRC also exhibited a good antibacterial property. Oil/water separation has become a pressing global challenge in the recent times due to the rapid increase in the development of industries, frequent oil spills, and chemical leakages. Therefore, it is in great demand to develop superwetting materials from bio-based and cheap substances for treating oil/water mixtures and emulsions. Herein, we prepared citric acid (CA)-modified cellulose materials (including cotton fabric and raw cotton) with superwetting properties through a green dip-coating approach. The as-prepared CA-modified cellulose materials showed superamphiphilicity in air and superoleophobicity underwater. The CA-modified cotton fabric (CMCF) can be utilized to treat oil/water mixtures and demonstrated remarkably high permeation fluxes (up to 107,900 L m−2h−1) along with excellent separation efficiency (>99.99 %). The CA-modified raw cotton (CMRC) was applied for separating both surfactant-stabilized oil-in-water and surfactant-stabilized water-in-oil emulsions (SSOIWEs and SSWIOEs) exhibiting ultra-high permeation fluxes (up to 8,960 and 25,080 L m−2h−1, respectively) under gravity. The separation efficiencies of SSOIWEs surpassed 99.18 % and the filtrates' oil purity for SSWIOEs exceeded 99.98 %. In addition, the CMRC could be used to treat dye aqueous solutions and dye-containing emulsions. Moreover, CMRC also exhibited good antibacterial properties. Because of their excellent oil/water mixtures and emulsions separation abilities, green preparation process, and ease of mass production, our CA-modified cellulose materials have notable potential for practical applications. [ABSTRACT FROM AUTHOR]

Atherosclerosis is a multifactorial inflammatory disease that may progress silently for long period, and it is also widely accepted as the main cause of cardiovascular diseases. To prevent atherosclerotic plaques from generating, imaging early molecular markers and quantifying the extent of disease progression are desired. During inflammation, circulating monocytes leave the bloodstream and migrate into incipient lipid accumulation in the artery wall, following conditioning by local growth factors and proinflammatory cytokines; therefore, monocyte accumulation in the arterial wall can be observed in fatty streaks, rupture-prone plaques, and experimental atherosclerosis. In this work, we synthesized monocyte-targeting iron oxide magnetic nanoparticles (MNPs), which were incorporated with the peptides derived from the chemokine receptor C-C chemokine receptor type 2 (CCR2)-binding motif of monocytes chemoattractant protein-1 (MCP-1) as a diagnostic tool for potential atherosclerosis. MCP-1-motif MNPs co-localized with monocytes in in vitro fluorescence imaging. In addition, with MNPs injection in ApoE knockout mice (ApoE KO mice), the well-characterized animal model of atherosclerosis, MNPs were found in specific organs or regions which had monocytes accumulation, especially the aorta of atherosclerosis model mice, through in vivo imaging system (IVIS) imaging and magnetic resonance imaging (MRI). We also performed Oil Red O staining and Prussian Blue staining to confirm the co-localization of MCP-1-motif MNPs and atherosclerosis. The results showed the promising potential of MCP-1-motif MNPs as a diagnostic agent of atherosclerosis. [ABSTRACT FROM AUTHOR]

• High-oxidation-state (hos) AgCl-assembled NPs was fabricated by a facile oxidation process in the PBS solution. • Achieved fast bacterial destruction and sustainable microbial control ability. • Hos/AgCl-assembled NP-induced temporary resistance via bacterial metabolism alteration. • Physico-chemical and biological evolution of temporary NP resistant bacteria. • New insights to the medical disinfectant application and environment control. Although inorganic silver-based nanoparticles (NPs) have been used to replace antibiotics to treat environmental microorganisms, the silver ion diffusion mechanism takes at least hours to poison the bacteria and cannot destruct the bacteria immediately. In this paper, we developed a concise oxidation process of heterostructured Ag@AuAg hollow NPs in a H 2 O 2 /PBS solution to generate AgCl nanocrystals and high-oxidation-state (hos) metal species. The hos/AgCl-assembled NPs offered a strong redox reaction to kill bacteria at 1.25 ppm [Ag] which was lower minimal inhibition concentration value than the utility of Ag ions and Ag NPs. A rapid meet-dip-kill process to disintegrate the bacterial membrane was observed within 60 min. The continuous release of Ag ions from AgCl blocks served as a smart bactericide to sustainably inhibit bacterial growth up to 7 days. The hos/AgCl-based bactericide induced enhanced evolution of a distinctive subpopulation with rigid membrane structure against both Ag ions and Ag-based NPs. This Ag-resistant persister behaved the downregulation of energy consumption and the physical insulation for Ag ions by secreting bio-reductants to convert Ag ions to less toxic Ag NPs. Based on our findings, hos/AgCl-assembled NPs endowed multiple antibacterial effects with no prominent findings of toxicity in the liver and kidneys, which opens a new era to understand the antimicrobial mechanism and resistant risk of Ag-related NPs for future clinical and environmental application. [ABSTRACT FROM AUTHOR]

In this work we developed methylene blue-immobilized copper-iron nanoparticles (MB-CuFe NPs) through a facile one-step hydrothermal reaction to achieve a better phototherapeutic effect. The Fe/Cu ratio of the CuFe NPs was controllable by merely changing the loading amount of iron precursor concentration. The CuFe NPs could serve as a Fenton catalyst to convert hydrogen peroxide (H2O2) into reactive oxygen species (ROS), while the superparamagnetic properties also suggest magnetic resonance imaging (MRI) potential. Furthermore, the Food and Drug Administration (FDA)-approved MB photosensitizer could strongly adsorb onto the surface of CuFe NPs to facilitate the drug delivery into cells and improve the photodynamic therapy at 660 nm via significant generation of singlet oxygen species, leading to enhanced cancer cell-damaging efficacy. An MTT (thiazolyl blue tetrazolium bromide) assay proved the low cytotoxicity of the CuFe NPs to cervical cancer cells (HeLa cells), namely above 80% at 25 ppm of the sample dose. A slight dissolution of Cu and Fe ions from the CuFe NPs in an acidic environment was obtained, providing direct evidence for CuFe NPs being degradable without the risk of long-term retention in the body. Moreover, the tremendous photo-to-thermal conversion of CuFe NPs was examined, which might be combined with photodynamic therapy (PDT) for promising development in the depletion of cancer cells after a single pulse of deep-red light irradiation at high laser power. [ABSTRACT FROM AUTHOR]