Shining at the Tips: Anisotropic Deposition of Pt Nanoparticles Boosting Hot Carrier Utilization for Plasmon-Driven Photocatalysis.

Bimetallic nanostructures are a promising candidate for plasmon-driven photocatalysis. However, knowledge on the generation and utilization of hot carriers in bimetallic nanostructures is still limited. In this work, we explored Pt position-dependent photocatalytic properties of bimetallic Au nanobipyramids (Au NBPs) with single-molecule fluorescence imaging. Compared with all-deposited core-shell nanostructures (aPt-Au NBPs), single-molecule imaging and simulation results show that the end-deposited bimetallic nanostructures (ePt-Au NBPs) can maintain a strong electromagnetic (EM) field and further promote the generation and transfer of energetic hot electrons for photocatalysis. Even though the Pt lattice is more stable than Au, the strong EM field at the sharp tips can boost lattice vibration, where enhanced spontaneous surface restructuring for active reaction site generation takes place. Significantly enhanced catalytic efficiency from ePt-Au NBPs is observed in contrast to that of Au NBPs and aPt-Au NBPs. These microscopic evidences offer valuable guidelines to design plasmon-based photocatalysts, particularly for bimetallic nanostructures.

Nucleolin-Targeting AS1411-Aptamer-Modified Graft Polymeric Micelle with Dual pH/Redox Sensitivity Designed To Enhance Tumor Therapy through the Codelivery of Doxorubicin/TLR4 siRNA and Suppression of Invasion.

In this article, a novel graft polymeric micelle with targeting function ground on aptamer AS1411 was synthesized. The micelle was based on chitosan-ss-polyethylenimine-urocanic acid (CPU) with dual pH/redox sensitivity and targeting effects. This micelle was produced for codelivering Toll-like receptor 4 siRNA (TLR4-siRNA) and doxorubicin (Dox). In vitro investigation revealed the sustained gene and drug release from Dox-siRNA-loaded micelles under physiological conditions, and this codelivery nanosystem exhibited high dual pH/redox sensitivity, rapid intracellular drug release, and improved cytotoxicity against A549 cells in vitro. Furthermore, the micelles loaded with TLR4-siRNA inhibited the migration and invasion of A549. Excellent tumor penetrating efficacy was also noted in the A549 tumor spheroids and solid tumor slices. In vivo, multiple results demonstrated the excellent tumor-targeting ability of AS1411-chitosan-ss-polyethylenimine-urocanic acid (ACPU) micelle in tumor tissues. The micelles exhibited excellent antitumor efficacy and low toxicity in the systemic circulation in lung-tumor-bearing BALB/c mice. These results conclusively demonstrated the great potential of the new graft copolymer micelle with targeting function for the targeted and efficient codelivery of chemotherapeutic drugs and genes in cancer treatment.

Effect of different carriers and operating parameters on degradation of flax wastewater by fluidized-bed Fenton process.

This investigation evaluates the effectiveness of a fluidized-bed Fenton process in treating flax wastewater. Flax wastewater was taken from a paper-making factory in a secondary sedimentation tank effluent of a paper-making factory in Hebei. The performance of three carriers (SiO2, Al2O3, Fe2O3) used in the reactor was compared, and the effects of different operational conditions, and Fenton reagent concentrations were studied. Experimental results indicated that SiO2 was the most appropriate carrier in the system. The dose of Fe2+ and H2O2 was a significant operating factor in the degradation progress. The bed expansion was considered to be another factor influencing the treatment effect. Under the appropriate conditions (300 mg/L Fe2+, 600 mg/L H2O2, and 74.07 g/L SiO2 as the carrier, at pH=3, 50% bed expansion), the highest removal rate of total organic carbon (TOC) and color was 89% and 94%, respectively. The article also discussed the process of the colority removal of flax wastewater and the kinetics of TOC removal.

Functional peptide conjugated ordered gold nanoparticles based rational electrochemical immunosensor for highly stable and selective detection of zearalenone.

To integrate antifouling properties and good sensitivity on the sensing interface can improve the applicability of an electrochemical immunosensor. These functional regions can be integrated into a single functional peptide (functPP). The rational designed three domains in functPP were the anchoring, antifouling and gold nanoparticles (AuNPs) recognizing domains. Meanwhile, the ordered AuNPs inspired by C15H23CO-RRRRR can be recognized by AuNPs recognizing domains in functPP to enhance the intensity of detecting current. In the sensing system, the anchoring domain in functPP can be immobilized on the Au electrode by AuS interaction, while the antifouling domain undergoes strong hydration with water molecules to resist matrices, and the recognizing domains can directionally capture O-AuNPs to form a functPP-O-AuNPs complex as the core sensing element. Consequently, the complex bound to the monoclonal antibodies against zearalenone by electrostatic adsorption to develop a highly antifouling and sensitive biosensor with the ability to identify zearalenone in cereals.

Leveraging affordances in an ecological stance: Reflective language teaching for professional development during COVID-19.

The COVID-19 pandemic has made a prominent impact of social contexts on teachers' professional development in remote classroom teaching. To explore how the change has altered human-environment relationships in university language classes, this qualitative case study investigated three teachers' progressive reflection on their use of affordances for teaching Chinese as a second language (L2) during COVID-19. Under the framework of human ecological language pedagogy, three themes of emergency remote teaching emerged from monthly semi-structured interviews about the three teachers' reflective practice in remote classrooms: computer-dominant teaching conditions, flexible classroom interaction, and rational social empathy in L2 education. The findings suggest the importance of a growth mindset for L2 teachers to leverage their teaching abilities and environmental resources for continuing professional development during COVID-19 and post-pandemic periods.

Stimuli-responsive nanoparticles for the codelivery of chemotherapeutic agents doxorubicin and siPD-L1 to enhance the antitumor effect.

Cancer cells have been reported to exhibit high resistance against immune system recognition through various cell intrinsic and extrinsic mechanisms. Considerable challenges have been encountered in monotherapy with chemotherapeutics to attain the desired antitumor efficacy. In this study, a nanodelivery system was designed to incorporate doxorubicin (DOX) and programmed death-ligand 1 (PD-L1) small interfering RNA (siRNA), that is, siPD-L1. DOX and siPD-L1 were formed from a stimuli-responsive polymer with a poly-L-lysine-lipoic acid reduction-sensitive core and a tumor extracellular pH-stimulated shedding polyethylene glycol layer. The codelivery system was stable under physiological pH conditions and demonstrated enhanced cellular uptake at the tumor site. Moreover, the combined treatment of DOX and siPD-L1 exhibited improved antitumor effect in vitro and in vivo compared with either modality alone. The combination of chemotherapy and immunotherapy presented in this work through the codelivery of a chemotherapeutic agent and a gene-silencing agent (siRNA) may provide a new strategy for cancer treatment.

Doxorubicin and siRNA-PD-L1 co-delivery with T7 modified ROS-sensitive nanoparticles for tumor chemoimmunotherapy.

Tumor cells avoid immunosurveillance during the tumorigenesis, metastasis and recurrence periods thanks to the overexpressed immunosuppressive molecules on their surface. For instance, the programmed cell death 1 ligand (PD-L1) binds with the T-cells' programmed cell death receptor 1 (PD-1) impairing the anti-tumor activity of the host T cells. In this study, a new reactive oxygen species (ROS) responsive nanoparticle (NP), modified with the HAIYPRH (T7) peptide, was developed for the co-delivery of siRNA-PD-L1 and doxorubicin (Dox). These NPs can block the inhibitory signal responding to T cells and enhance cytotoxicity of Dox against tumor cells. The T7 modification binds to the overexpressed transferrin receptor on tumor cells facilitating its cellular uptake. Dox rapid release is then triggered by the high tumor cells cytoplasmic concentration of ROS, leading to cell apoptosis. Our results demonstrated these NPs exhibited a T7-mediated cellular uptake and an intracellular ROS-triggered payloads release in vitro. They also suggested an improved in vivo 4T1 tumor targeting efficiency and chemoimmunotherapy. Most notably, the co-delivery system exhibited a significantly enhanced antitumor effect over Dox-only loaded NPs following prompting the proliferation of T cells by siRNA-PD-L1. In conclusion, these ROS-responsive NPs provided a promising strategy to combine siRNA-PD-L1 immunotherapy and Dox chemotherapy.

Co-delivery of VEGF siRNA and Etoposide for Enhanced Anti-angiogenesis and Anti-proliferation Effect via Multi-functional Nanoparticles for Orthotopic Non-Small Cell Lung Cancer Treatment.

Targeting tumor angiogenesis pathway via VEGF siRNA (siVEGF) has shown great potential in treating highly malignant and metastatic non-small cell lung cancer (NSCLC). However, anti-angiogenic monotherapy lacked sufficient antitumor efficacy which suffered from malignant tumor proliferation. Therefore, the combined application of siVEGF and chemotherapeutic agents for simultaneous targeting of tumor proliferation and angiogenesis has been a research hotspot to explore a promising NSCLC therapy regimen. Methods: We designed, for the first time, a rational therapy strategy via intelligently co-delivering siVEGF and chemotherapeutics etoposide (ETO) by multi-functional nanoparticles (NPs) directed against the orthotopic NSCLC. These NPs consisted of cationic liposomes loaded with siVEGF and ETO and then coated with versatile polymer PEGylated histidine-grafted chitosan-lipoic acid (PHCL). We then comprehensively evaluated the anti-angiogenic and anti-proliferation efficiency in the in vitro tumor cell model and in bioluminescent orthotopic lung tumor bearing mice model. Results: The NPs co-delivering siVEGF and ETO exhibited tailor-made surface charge reversal features in mimicking tumor extracellular environment with improved internal tumor penetration capacity and higher cellular internalization. Furthermore, these NPs with flexible particles size triggered by intracellular acidic environment and redox environment showed pinpointed and sharp intracellular cargo release guaranteeing adequate active drug concentration in tumor cells. Enhanced VEGF gene expression silencing efficacy and improved tumor cell anti-proliferation effect were demonstrated in vitro. In addition, the PHCL layer improved the stability of these NPs in neutral environment allowing enhanced orthotopic lung tumor targeting efficiency in vivo. The combined therapy by siVEGF and ETO co-delivered NPs for orthotopic NSCLC simultaneously inhibited tumor proliferation and tumor angiogenesis resulting in more significant suppression of tumor growth and metastasis than monotherapy. Conclusion: Combined application of siVEGF and ETO by the multi-functional NPs with excellent and on-demand properties exhibited the desired antitumor effect on the orthotopic lung tumor. Our work has significant potential in promoting combined anti-angiogenesis therapy and chemotherapy regimen for clinical NSCLC treatment.

Stepwise pH/reduction-responsive polymeric conjugates for enhanced drug delivery to tumor.

In this research, a charge-conversional polymer, poly-l-lysine-lipoic acid (PLL-LA), was prepared by dimethylmaleic anhydride (DA) modification and applied as a carrier with enhanced cell internalization and intracellular pH- and reduction-triggered doxorubicin (Dox) release. The surface charge of dimethylmaleic anhydride-poly-l-lysine-lipoic acid micelles (DA-PLL-LA) was negative at physiological pH and reversed to positive at the extracellular and intracellular pH of cancer cells. At tumor extracellular pH of 6.8, the conjugates underwent a rapid charge-reversible process with almost 80% DA cleavage within 2h, and then endocytosed into the endo/lysosomes more rapidly than at physiological pH of 7.4. The Dox/DA-PLL-LA micelles (Dox-micelles) demonstrated a sustained drug release in vitro under physiological condition, and rapid Dox release was triggered by both extracellular pH and high-concentration reducing glutathione. The Dox-micelles also exhibited enhanced internalization at extracellular pH, rapid intracellular drug release, and improved cytotoxicity against A549 cells in vitro. Excellent tumor-penetrating efficacy was also found in A549 tumor spheroids and solid tumor slices. Moreover, the DA-PLL-LA micelles exhibited excellent tumor-targeting ability in tumor tissues and excellent antitumor efficacy and low systemic toxicity in breast tumor-bearing mice. Therefore, the DA-PLL-LA micelles demonstrated great potential for targeted and efficient drug delivery in cancer treatments.

Fluidized-bed Fenton coupled with ceramic membrane separation for advanced treatment of flax wastewater.

Fluidized-bed Fenton coupled with ceramic membrane separation to treat the flax secondary effluent was investigated. The operating variables, including initial pH, dosage of H2O2 and Fe0, air flow rate, TMP and pore size, were optimized. The distributions of DOMs in the treatment process were analyzed. Under the optimum condition (600mgL-1H2O2, 1.4gL-1 Fe0, pH=3, 300Lh-1 air flow rate and 15psi TMP), the highest TOC and color removal efficiencies were 84% and 94% in the coupled reactor with 100nm ceramic membrane, reducing 39% of total iron with similar removal efficiency compared with Fluidized-bed Fenton. Experimental results showed that the ceramic membrane could intercept catalyst particles (average particle size >100nm), 10.4% macromolecules organic matter (AMW>20000Da) and 12.53% hydrophobic humic-like component. EEM-PARAFAC identified four humic-like (M1-M4) and one protein-like components (M5), and the fluorescence intensities of M1-M5 in the secondary effluent were 63.27, 63.05, 33.41, 16.71 and 0.72 QSE, respectively. After the coupled treatment, the removal efficiencies of M1(81%), M2(86%) were higher than M3, M4(63%, 61%). Pearson correlation analysis suggested that M1, M2 and M3 were the major contributors to the cake layer, and M4, M5 might more easily lead to pore blockages.