Nanocatalysts for modulating antitumor immunity: fabrication, mechanisms and applications.

Immunotherapy harnesses the inherent immune system in the body to generate systemic antitumor immunity, offering a promising modality for defending against cancer. However, tumor immunosuppression and evasion seriously restrict the immune response rates in clinical settings. Catalytic nanomedicines can transform tumoral substances/metabolites into therapeutic products in situ, offering unique advantages in antitumor immunotherapy. Through catalytic reactions, both tumor eradication and immune regulation can be simultaneously achieved, favoring the development of systemic antitumor immunity. In recent years, with advancements in catalytic chemistry and nanotechnology, catalytic nanomedicines based on nanozymes, photocatalysts, sonocatalysts, Fenton catalysts, electrocatalysts, piezocatalysts, thermocatalysts and radiocatalysts have been rapidly developed with vast applications in cancer immunotherapy. This review provides an introduction to the fabrication of catalytic nanomedicines with an emphasis on their structures and engineering strategies. Furthermore, the catalytic substrates and state-of-the-art applications of nanocatalysts in cancer immunotherapy have also been outlined and discussed. The relationships between nanostructures and immune regulating performance of catalytic nanomedicines are highlighted to provide a deep understanding of their working mechanisms in the tumor microenvironment. Finally, the challenges and development trends are revealed, aiming to provide new insights for the future development of nanocatalysts in catalytic immunotherapy.

Regulation Dipole Moments of N-Doped Graphene Coordinated with FePc Toward Highly Efficient Microwave Absorption Performance in C Band.

The development of composites with highly efficient microwave absorption (MA) performance deeply depends on polarization loss, which can be induced by charge redistribution. Considering the fact that polarization centers can be easily obtained in graphene, herein, iron phthalocyanine (FePc) is used as polarization site to coordinate with nitrogen-doped graphene (FePc/N-rGO) to optimize MA performance comprehensively. The factors influencing MA properties focus on the interaction between FePc and N-rGO, and the change of dipole moments. The density functional theory (DFT) results demonstrated that FePc has strong interaction with N defect sites in graphene. The charge loss for FePc and charge accumulation for N-rGO occurred, leading to great increase of dipole moment, and the increased dipole moment can be acted as a descriptor to evaluate the enhanced polarization loss. Due to high charge redistribution capacity of N defect sites and FePc polarization centers, the FePc/N-rGO showed excellent MA properties in C band, and the minimum reflection loss value can reach -49.3 dB at 5.4 GHz with thickness of 3.8 mm. In addition, the fabric loaded with FePc/N-rGO showed good heat dissipation property. This work opens the door to the development of MA performance bound to polarization site with dipole moment.

Phase-Transition of Mo2C Induced by Tungsten Doping as Heterointerface-Rich Electrocatalyst for Optimizing Hydrogen Evolution Activity.

Electrochemical hydrogen evolution reaction (HER) from water splitting driven by renewable energy is considered a promising method for large-scale hydrogen production, and as an alternative to noble-metal electrocatalysts, molybdenum carbide (Mo2C) has exhibited effective HER performance. However, the strong bonding strength of intermediate adsorbed H (Hads) with Mo active site slows down the HER kinetics of Mo2C. Herein, using phase-transition strategy, hexagonal ß-Mo2C could be easily transferred to cubic δ-Mo2C through electron injection triggered by tungsten (W) doping, and heterointerface-rich Mo2C-based composites, including ß-Mo2C, δ-Mo2C, and MoO2, are presented. Experimental results and density functional theory calculations reveal that W doping mainly contributes to the phase-transition process, and the generated heterointerfaces are the dominant factor in inducing remarkable electron accumulation around Mo active sites, thus weakening the Mo─H coupling. Wherein, the ß-Mo2C/MoO2 interface plays an important role in optimizing the electronic structure of Mo 3d orbital and hydrogen adsorption Gibbs free energy (ΔGH*), enabling these Mo2C-based composites to have excellent intrinsic catalytic activity like low overpotential (η10 = 99.8 mV), small Tafel slope (60.16 dec-1), and good stability in 1 m KOH. This work sheds light on phase-transition engineering and offers a convenient route to construct heterointerfaces for large-scale HER production.

Recent Advances in Electrochemical Sensors for Formaldehyde.

Formaldehyde, a ubiquitous indoor air pollutant, plays a significant role in various biological processes, posing both environmental and health challenges. This comprehensive review delves into the latest advancements in electrochemical methods for detecting formaldehyde, a compound of growing concern due to its widespread use and potential health hazards. This review underscores the inherent advantages of electrochemical techniques, such as high sensitivity, selectivity, and capability for real-time analysis, making them highly effective for formaldehyde monitoring. We explore the fundamental principles, mechanisms, and diverse methodologies employed in electrochemical formaldehyde detection, highlighting the role of innovative sensing materials and electrodes. Special attention is given to recent developments in nanotechnology and sensor design, which significantly enhance the sensitivity and selectivity of these detection systems. Moreover, this review identifies current challenges and discusses future research directions. Our aim is to encourage ongoing research and innovation in this field, ultimately leading to the development of advanced, practical solutions for formaldehyde detection in various environmental and biological contexts.

Recent Advances in Photoswitchable Fluorescent and Colorimetric Probes.

In recent years, significant advancements have been made in the research of photoswitchable probes. These probes undergo reversible structural and electronic changes upon light exposure, thus exhibiting vast potential in molecular detection, biological imaging, material science, and information storage. Through precisely engineered molecular structures, the photoswitchable probes can toggle between "on" and "off" states at specific wavelengths, enabling highly sensitive and selective detection of targeted analytes. This review systematically presents photoswitchable fluorescent and colorimetric probes built on various molecular photoswitches, primarily focusing on the types involving photoswitching in their detection and/or signal response processes. It begins with an analysis of various molecular photoswitches, including their photophysical properties, photoisomerization and photochromic mechanisms, and fundamental design concepts for constructing photoswitchable probes. The article then elaborates on the applications of these probes in detecting diverse targets, including cations, anions, small molecules, and biomacromolecules. Finally, it offers perspectives on the current state and future development of photoswitchable probes. This review aims to provide a clear introduction for researchers in the field and guidance for the design and application of new, efficient fluorescent and colorimetric probes.

Novel therapeutic role of Ganoderma Polysaccharides in a septic mouse model - The key role of macrophages.

Ganoderma lucidum polysaccharides (G. PS) have been recognized for their immune-modulating properties. In this study, we investigated the impact of G. PS in a sepsis mouse model, exploring its effects on survival, inflammatory cytokines, Treg cell differentiation, bacterial load, organ dysfunction, and related pathways. We also probed the role of macrophages through chlorphosphon-liposome pretreatment. Using the cecal ligation and puncture (CLP) model, we categorized mice into normal, PBS, and G. PS injection groups. G. PS significantly enhanced septic mouse survival, regulated inflammatory cytokines (TNF-α, IL-17A, IL-6, IL-10), and promoted CD4+Foxp3+ Treg cell differentiation in spleens. Additionally, G. PS reduced bacterial load, mitigated organ damage, and suppressed the NF-κB pathway. In vitro, G. PS facilitated CD4+ T cell differentiation into Treg cells via the p-STAT5 pathway. Chlorphosphon-liposome pretreatment heightened septic mortality, bacterial load, biochemical markers, and organ damage, emphasizing macrophages' involvement. G. PS demonstrated significant protective effects in septic mice by modulating inflammatory responses, enhancing Treg cell differentiation, diminishing bacterial load, and inhibiting inflammatory pathways. These findings illuminate the therapeutic potential of G. PS in sepsis treatment.

Nitric oxide-releasing multifunctional catechol-modified chitosan/oxidized dextran hydrogel with antibacterial, antioxidant, and pro-angiogenic properties for MRSA-infected diabetic wound healing.

The study presents a multifunctional catechol-modified chitosan (Chi-Ca)/oxidized dextran (Dex-CHO) hydrogel (CDP-PB) that possesses antibacterial, antioxidant, and pro-angiogenic properties, aimed at improving the healing of diabetic wounds. The achievement of the as-prepared CDP-PB hydrogel with superb antibacterial property (99.9 %) can be realized through the synergistic effect of phenylboronic acid-modified polyethyleneimine (PEI-PBA) and photothermal therapy (PTT) of polydopamine nanoparticles loaded with the nitric oxide (NO) donor BNN6 (PDA@BNN6). Notably, CDP-PB hydrogel achieves ∼3.6 log10 CFU/mL MRSA of inactivation efficiency under 808 nm NIR laser irradiation. In order to mitigate oxidative stress, the Chi-Ca was synthesized and afterward subjected to a reaction with Dex-CHO via a Schiff-base reaction. The catechol-containing hydrogel demonstrated its effectiveness in scavenging DPPH, •OH, and ABTS radicals (> 85 %). In addition, the cellular experiment illustrates the increased migration and proliferation of cells by the treatment of CDP-PB hydrogel in the presence of oxidative stress conditions. Moreover, the findings from the animal model experiments provide evidence that the CDP-PB hydrogel exhibited efficacy in the eradication of wound infection, facilitation of angiogenesis, stimulation of granulation, and augmentation of collagen deposition. These results indicate the potential of the CDP-PB hydrogel for use in clinical applications.

Engineering CaP-Pickering emulsion for enhanced mRNA cancer vaccines via dual DC and NK activations.

mRNA delivery systems, such as lipid nanoparticle (LNP), have made remarkable strides in improving mRNA expression, whereas immune system activation operates on a threshold. Maintaining a delicate balance between antigen expression and dendritic cell (DC) activation is vital for effective immune recognition. Here, a water-in-oil-in-water (w/o/w) Pickering emulsion stabilized with calcium phosphate nanoparticles (CaP-PME) is developed for mRNA delivery in cancer vaccination. CaP-PME efficiently transports mRNA into the cytoplasm, induces pro-inflammatory responses and activates DCs by disrupting intracellular calcium/potassium ions balance. Unlike LNP, CaP-PME demonstrates a preference for DCs, enhancing their activation and migration to lymph nodes. It elicits interferon-γ-mediated CD8+ T cell responses and promotes NK cell proliferation and activation, leading to evident NK cells infiltration and ameliorated tumor microenvironment. The prepared w/o/w Pickering emulsion demonstrates superior anti-tumor effects in E.G7 and B16-OVA tumor models, offering promising prospects as an enhanced mRNA delivery vehicle for cancer vaccinations.