TET-mediated 5hmC in breast cancer: mechanism and clinical potential

Breast cancer is the most common cancer among women, with differences in clinical features due to its distinct molecular subtypes. Current studies have demonstrated that epigenetic modifications play a crucial role in regulating the progression of breast cancer. Among these mechanisms, DNA demethylation and its reverse process have been studied extensively for their roles in activating or silencing cancer related gene expression. Specifically, Ten-Eleven Translocation (TET) enzymes are involved in the conversion process from 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), which results in a significant difference in the global level of 5hmC in breast cancer compared with normal tissues. In this review, we summarize the functions of TET proteins and the regulated 5hmC levels in the pathogenesis of breast cancer. Discussions on the clinical values of 5hmC in early diagnosis and the prediction of prognosis are also mentioned.

Development and application of an uncapped mRNA platform

BACKGROUND

A novel uncapped mRNA platform was developed.

METHODS

Five lipid nanoparticle (LNP)-encapsulated mRNA constructs were made to evaluate several aspects of our platform, including transfection efficiency and durability in vitro and in vivo and the activation of humoral and cellular immunity in several animal models. The constructs were eGFP-mRNA-LNP (for enhanced green fluorescence mRNA), Fluc-mRNA-LNP (for firefly luciferase mRNA), SδT-mRNA-LNP (for Delta strain SARS-CoV-2 spike protein trimer mRNA), gDED-mRNA-LNP (for truncated glycoprotein D mRNA coding ectodomain from herpes simplex virus type 2 (HSV2)) and gDFR-mRNA-LNP (for truncated HSV2 glycoprotein D mRNA coding amino acids 1-400).

RESULTS

Quantifiable target protein expression was achieved in vitro and in vivo with eGFP- and Fluc-mRNA-LNP. SδT-mRNA-LNP, gDED-mRNA-LNP and gDFR-mRNA-LNP induced both humoral and cellular immune responses comparable to those obtained by previously reported capped mRNA-LNP constructs. Notably, SδT-mRNA-LNP elicited neutralizing antibodies in hamsters against the Omicron and Delta strains. Additionally, gDED-mRNA-LNP and gDFR-mRNA-LNP induced potent neutralizing antibodies in rabbits and mice. The mRNA constructs with uridine triphosphate (UTP) outperformed those with N1-methylpseudouridine triphosphate (N1mψTP) in the induction of antibodies via SδT-mRNA-LNP.

CONCLUSIONS

Our uncapped, process-simplified and economical mRNA platform may have broad utility in vaccines and protein replacement drugs.KEY MESSAGESThe mRNA platform described in our paper uses internal ribosome entry site (IRES) (Rapid, Amplified, Capless and Economical, RACE; Register as BH-RACE platform) instead of caps and uridine triphosphate (UTP) instead of N1-methylpseudouridine triphosphate (N1mψTP) to synthesize mRNA.Through the self-developed packaging instrument and lipid nanoparticle (LNP) delivery system, mRNA can be expressed in cells more efficiently, quickly and economically.Particularly exciting is that potent neutralizing antibodies against Delta and Omicron real viruses were induced with the new coronavirus S protein mRNA vaccine from the BH-RACE platform.

Exploring RNA modifications in infectious non-coding circular RNAs

Viroids, small circular non-coding RNAs, act as infectious pathogens in higher plants, demonstrating high stability despite consisting solely of naked RNA. Their dependence of replication on host machinery poses the question of whether RNA modifications play a role in viroid biology. Here, we explore RNA modifications in the avocado sunblotch viroid (ASBVd) and the citrus exocortis viroid (CEVd), representative members of viroids replicating in chloroplasts and the nucleus, respectively, using LC - MS and Oxford Nanopore Technology (ONT) direct RNA sequencing. Although no modification was detected in ASBVd, CEVd contained approximately one m6A per RNA molecule. ONT sequencing predicted three m6A positions. Employing orthogonal SELECT method, we confirmed m6A in two positions A353 and A360, which are highly conserved among CEVd variants. These positions are located in the left terminal region of the CEVd rod-like structure where likely RNA Pol II and and TFIIIA-7ZF bind, thus suggesting potential biological role of methylation in viroid replication.

Exogenously applied ABA alleviates dysplasia of maize (Zea mays L.) ear under drought stress by altering photosynthesis and sucrose transport

Drought stress inhibits the development of maize ears. Abscisic acid (ABA) is a plant hormone that can regulate the physicology metabolism under abiotic stress. In this study, maize varieties Zhengdan 958 (ZD958) and Xianyu 335 (XY335) with different filling stages were used as materials. Three treatments were set in the filling period: normal irrigation (CK), drought stress (stress); exogenous ABA + drought stress (ABA+stress). They were used to study the physiological regulation of exogenous ABA on maize ears development during drought stress. Exogenous ABA inhibited bald tip and the decline of maize plant biomass, and increased the number and weight of grains per ear at harvest under drought stress by regulating photosynthetic pigment content (Chla, Chlb, Car), gas exchange parameters (Pn, Tr, gs, Ci, Ls), Chla fluorescence parameters (Fv/Fm, ФPSII, ETR, qP, NPQ), chloroplast structure and function, photosynthetic enzyme activity, and the transcription level of genes coding SUTs (ZmSUT1, ZmSUT2, ZmSUT4, ZmSUT6). There was a significant correlation between physiological indexes of sucrose loading in maize and yield factors. This study discussed the mechanism of exogenous ABA alleviating maize ear dysplasia at grain filling stage under drought stress from the perspective of photosynthesis and sucrose transport.

Targeting capabilities of engineered extracellular vesicles for the treatment of neurological diseases

Recent advances in research on extracellular vesicles have significantly enhanced their potential as therapeutic agents for neurological diseases. Owing to their therapeutic properties and ability to cross the blood-brain barrier, extracellular vesicles are recognized as promising drug delivery vehicles for various neurological conditions, including ischemic stroke, traumatic brain injury, neurodegenerative diseases, glioma, and psychosis. However, the clinical application of natural extracellular vesicles is hindered by their limited targeting ability and short clearance from the body. To address these limitations, multiple engineering strategies have been developed to enhance the targeting capabilities of extracellular vesicles, thereby enabling the delivery of therapeutic contents to specific tissues or cells. Therefore, this review aims to highlight the latest advancements in natural and targeting-engineered extracellular vesicles, exploring their applications in treating traumatic brain injury, ischemic stroke, Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, glioma, and psychosis. Additionally, we summarized recent clinical trials involving extracellular vesicles and discussed the challenges and future prospects of using targeting-engineered extracellular vesicles for drug delivery in treating neurological diseases. This review offers new insights for developing highly targeted therapies in this field.

Nanocarrier-mediated siRNA delivery: a new approach for the treatment of traumatic brain injury-related Alzheimer's disease

Traumatic brain injury and Alzheimer's disease share pathological similarities, including neuronal loss, amyloid-β deposition, tau hyperphosphorylation, blood-brain barrier dysfunction, neuroinflammation, and cognitive deficits. Furthermore, traumatic brain injury can exacerbate Alzheimer's disease-like pathologies, potentially leading to the development of Alzheimer's disease. Nanocarriers offer a potential solution by facilitating the delivery of small interfering RNAs across the blood-brain barrier for the targeted silencing of key pathological genes implicated in traumatic brain injury and Alzheimer's disease. Unlike traditional approaches to neuroregeneration, this is a molecular-targeted strategy, thus avoiding non-specific drug actions. This review focuses on the use of nanocarrier systems for the efficient and precise delivery of siRNAs, discussing the advantages, challenges, and future directions. In principle, siRNAs have the potential to target all genes and non-targetable proteins, holding significant promise for treating various diseases. Among the various therapeutic approaches currently available for neurological diseases, siRNA gene silencing can precisely "turn off" the expression of any gene at the genetic level, thus radically inhibiting disease progression; however, a significant challenge lies in delivering siRNAs across the blood-brain barrier. Nanoparticles have received increasing attention as an innovative drug delivery tool for the treatment of brain diseases. They are considered a potential therapeutic strategy with the advantages of being able to cross the blood-brain barrier, targeted drug delivery, enhanced drug stability, and multifunctional therapy. The use of nanoparticles to deliver specific modified siRNAs to the injured brain is gradually being recognized as a feasible and effective approach. Although this strategy is still in the preclinical exploration stage, it is expected to achieve clinical translation in the future, creating a new field of molecular targeted therapy and precision medicine for the treatment of Alzheimer's disease associated with traumatic brain injury.

Engineering multifunctional surface topography to regulate multiple biological responses

Surface topography or curvature plays a crucial role in regulating cell behavior, influencing processes such as adhesion, proliferation, and gene expression. Recent advancements in nano- and micro-fabrication techniques have enabled the development of biomimetic systems that mimic native extracellular matrix (ECM) structures, providing new insights into cell-adhesion mechanisms, mechanotransduction, and cell-environment interactions. This review examines the diverse applications of engineered topographies across multiple domains, including antibacterial surfaces, immunomodulatory devices, tissue engineering scaffolds, and cancer therapies. It highlights how nanoscale features like nanopillars and nanospikes exhibit bactericidal properties, while many microscale patterns can direct stem cell differentiation and modulate immune cell responses. Furthermore, we discuss the interdisciplinary use of topography for combined applications, such as the simultaneous regulation of immune and tissue cells in 2D and 3D environments. Despite significant advances, key knowledge gaps remain, particularly regarding the effects of topographical cues on multicellular interactions and dynamic 3D contexts. This review summarizes current fabrication methods, explores specific and interdisciplinary applications, and proposes future research directions to enhance the design and utility of topographically patterned biomaterials in clinical and experimental settings.

Emerging screening platform characterises aminoquinoline structure-activity relationships with phospholipid layers

Aminoquinolines (AQ) and substituted aminoquinolines (s-AQ) interact with electrochemically monitored supported dioleoyl phosphatidylcholine (DOPC) monolayers and immobilised artificial membranes (IAM) on HPLC column. The electrochemical sensor records adsorption/partition of the compound on and into the layer as well as specific interactions due to the location of the compound in the layer. HPLC-IAM technology measures the partition coefficient between the solution and phospholipid including partition due to interaction of the positive molecular charge with the phospholipid polar heads. The monolayer interaction results were combined and normalised for the neutral compounds' lipophilicity as a log biomembrane affinity index ('log BAI') to exemplify charge and structural features in the interaction. A ChimeraX molecular modelling procedure was used to aid in the results interpretation. A compound ToxScore value was derived from 5 in vitro assays. The 'log BAI' exhibited a linear relationship with the AQ pKa values showing that the interaction was related to the molecular positive charge and to the electron donating properties of the -NH2 group. The correlation outliers showed a tendency/no tendency to H-bonding with the polar groups and a superficial/deeper location respectively in the phospholipid layer. The s-AQ 'log BAI' value displayed a power correlation with the compounds' ToxScore values.

Aptamer-based and highly sensitive electrochemical label-free gliotoxin biosensor via a dual recycling signal amplification cascade strategy

Gliotoxin (GT), a mycotoxin produced by Aspergillus fumigatus, exerts immunosuppressive and pro-apoptotic effects on mammalian cells, posing severe health threat upon human. Ultrasensitively and selectively detecting GT is therefore of great significance. In this work, on the basis of a new GT-specific aptamer, we describe construction of electrochemical label-free biosensor for GT with high sensitivity via exonuclease III (Exo III)-aided dual recycling signal amplification strategy. Target GT analyte combines with the aptamer recognition probe in the aptamer/ssDNA duplex to liberate the ssDNA, which hybridizes with the assistant hairpin to trigger the dual recycling cleavage of the G-quadruplex strand-containing signal hairpin on the electrode with the presence of Exo III. As a result, a substantial number of free G-quadruplex strands are generated. Consequently, aided by K+ ions, these G-quadruplexes bind and confine many hemin molecules on the electrode, which are subjected by electro-reduction for the generation of highly amplified current for label-free GT assay with 3.14 pM detection limit. In addition, such aptamer biosensor is also demonstrated with high selectivity and amenable for detecting GT in diluted human serums, highlighting its promising potentials for the convenient diagnosis of GT-associated diseases.

A non-solvatochromic fluorescent probe for imaging of lipid droplets in live cells and tissues

Lipid droplets (LDs) have recently attracted considerable attention owing to their crucial roles in both biological processes and disease pathogenesis. Visualization of LDs is fundamental for elucidating their roles in biological mechanisms and facilitating the early detection of diseases. Donor-acceptor (D-A) typed fluorescent probes have been extensively designed and utilized for the detection of LDs. However, such probes often exhibit a pronounced solvatochromic effect, leading to several limitations in detecting LDs, such as short excitation/emission wavelength, low specificity. Herein, we reported a non-solvatochromic D-A typed fluorescent probe S7 for LDs imaging in live cells and in vivo. S7 is polarity-dependent, which exhibits a very weak fluorescence in high-polar solvents owing to the photoinduced electron transfer (PET) mechanism but intense fluorescence in low-polarity environments without undergoing a solvatochromic blue shift. Except polarity, the fluorescent signal of S7 remains unaffected by factors such as viscosity, pH, ions, reactive oxygen species, reactive sulfur species, nucleic acids, proteins, and other biological molecules, allowing it to selectively light up LDs in live cells. Furthermore, this probe S7 exhibits an enhanced fluorescence intensity in tumor tissue when compared to normal tissue. This characteristic potentially provides an efficient and straightforward approach for tumor diagnosis.

Characterization of boron doped diamond electrodes with engineered sp2 carbon content and their application to structure-dependent DNA hybridization

Boron doped diamond electrodes brought a new potential in bioanalytical chemistry including studies of structure and interactions of nucleic acids. Herein, deposition conditionswere optimized to produce a set of polycrystalline BDD electrodes with comparable boron concentration in solid phase of (1.8 - 2.1) · 1021 cm-3 akin to metallic-type conductivity but with increasing sp2carbon content. Increase of[CH4]/[H2]from 0.25 % to 2.0 % during deposition led to an obvious decrease in grain size from ca.300 nm (BDD0.25) to < 100 nm (BDD2.0). Adsorption of oligodeoxynucleotides and their structural changes in the presence of K+ and Li+ ions were evaluated through enzyme-linked DNA hybridization assay in which oxidizable 1-naphthol was released from its phosphoesterbystreptavidin-alkaline phosphatase conjugate upon successful hybridization of the target oligodeoxynucleotide with a biotinylated complementary probe. With increasing sp2carbon content, the hybridization assay showed improved discrimination between a target forming guanine quadruplex (stabilized by K+ ions), yielding by 40 % - 60 % lower hybridization signal with the complementary probe, compared to the same but unstructured target oligodeoxynucleotide in the presence of Li+ions that don't stabilize the quadruplex structure. Such behaviour was observed also for commercial BDD electrode with surface roughness < 10 nm.

A nano-enabled adjunctive therapy to prevent vancomycin resistance evolution: Toward nano-anti-antibiotics

Vancomycin (VAN), a cationic glycopeptide antibiotic, represents a last-resort therapeutic remedy for life-threatening infections caused by multidrug resistant Gram-positive pathogens. However, biliary excretion of intravenously administered VAN in the gastrointestinal (GI) tract results in the VAN-resistant Enterococcus faecium emergence, a major cause of hospital-acquired infections. Instead of developing new antibiotics, we hypothesize that breaking the connection between intravenous antibiotic use and GI antimicrobial resistance may protect current antibiotics. Here, we develop a novel anti-VAN material via hybridizing hairy cellulose nanocrystals with a Food and Drug Administration (FDA)-approved resin to remove the excess antibiotic from the GI tract before it impacts bacteria and selects for resistance. In vitro studies show that VAN removal is regulated by electrostatic interactions via a time-dependent diffusion-controlled process that is not significantly influenced by the physiological pH, ionic strength, or the components of simulated intestinal fluid. Aligned with the in vitro findings, the oral administration of anti-VAN adjuvant effectively sequesters VAN in the murine GI tract and prevents the VAN resistance enrichment following the VAN treatment of E. faecium colonized mice. The anti-VAN adjunctive therapy may protect intravenous VAN, which is a step forward in addressing the global threat of antimicrobial resistance.

Chromium-functionalized metal-organic frameworks as highly sensitive, dual-mode sensors for real time and rapid detection of dopamine

Dopamine (DA): the brain's "feel-good" chemical that keeps us motivated, happy, and ready to take on the world. This essential neurotransmitter is involved in various physiological processes such as motor control, reward, and mood regulation. Dysregulation of DA levels is linked to several neurodegenerative diseases, emphasizing the need for sensitive and accurate detection methods for both diagnostic and therapeutic purposes. Fluorometric sensing presents an appealing, cost-effective approach to detect DA, especially in complex biological fluids. In this study, we report the synthesis and application of chromium-based metal-organic frameworks (MOFs), Cr-IA and Cr-BTC (IA: itaconic acid and BTC: benzene-1,2,4-tricarboxylic acid), as highly sensitive fluorometric sensors for DA detection in bio-fluids. Cr-IA and Cr-BTC MOFs were synthesized using a solvothermal method with their respective ligands and chromium salts, utilizing a mixed solvent system comprising water, ethanol, and dimethylformamide (DMF). Both MOFs were characterized using a variety of techniques, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), zeta potential measurements, and energy-dispersive X-ray spectroscopy (EDS) that provided essential information on the structural integrity, surface morphology, crystallinity, thermal stability, and surface charge properties of the MOFs, confirming the successful synthesis and characterization of both materials. The synthesized MOFs exhibited remarkable fluorometric sensing capabilities for dopamine detection in HEPES buffer, aqueous solution, and human serum, showcasing strong fluorescence response with high sensitivity, selectivity, and stability across a wide pH range. Cr-IA MOF demonstrated a 3.4-fold fluorescence intensity increase in HEPES buffer, while Cr-BTC MOF achieved a 5-fold enhancement. Both MOFs showed low limits of detection, with Cr-IA and Cr-BTC achieving 21 nM and 41 nM in HEPES buffer, and 26 nM and 20 nM in water, respectively. Fluorescence quenching and visible color changes upon dopamine addition enabled real-time and visual detection, while their dose-response behavior in human serum further validated their reliability for bioanalytical applications. Cytotoxicity studies confirmed their biocompatibility, ensuring their safe use in biological systems. These findings establish Cr-IA and Cr-BTC as highly promising materials for diagnostic and therapeutic monitoring, offering potential for clinical diagnostics and broader biomedical applications.

Stromal cell-derived factor-encapsulated nanoparticles target ischemic myocardium and attenuate myocardial injury via proangiogenic effects

Lipid bilayer nanoparticles (NPs) with and without stromal cell-derived factor (SDF) were created to target and treat ischemia/reperfusion (I/R)-injured myocardium. Male Wistar rats were subjected to myocardial I/R insult and, at reperfusion, randomized to receive systemic injections of 5 mL/kg PBS, 6 μg/kg of NPs, SDF, or SDF-NPs. Four days after treatment, SDF-NPs circulated and accumulated selectively in the ischemic myocardium, with an SDF concentration roughly three times that of the other three treatments. SDF-NP-treated rats had more endothelial progenitor cells (EPCs) in the blood and preserved capillaries and arterioles in the ischemic border myocardium four weeks post-treatment, which improved microvascular perfusion, reduced fibrosis, and preserved heart function. Notably, hearts treated with SDF-NPs retained left ventricular function at four weeks compared to 1-day post-treatment, with a 2.7 ± 1.2 % increase in the ejection fraction. The other three treatments decreased left ventricular function at four weeks (PBS: -7.8 ± 1.2 %, P < 0.001; empty NPs: -3.9 ± 1.3 %, P = 0.004; SDF solution: -5.1 ± 1.3 %, P = 0.001). Hence, systemically injected SDF-NPs selectively accumulate in ischemic cardiac tissue, shielding the myocardium from I/R injury via angiogenic effects through increased EPC migration. This novel cardioprotective drug may be clinically translatable.

Micropore structure engineering of injectable granular hydrogels via controlled liquid-liquid phase separation facilitates regenerative wound healing in mice and pigs

Biomaterials can play a crucial role in facilitating tissue regeneration, but their application is often limited by that they induce scarring rather than complete tissue restoration. Hydrogels with microporous architectures, engineered via 3D printing techniques or particle packing (granular hydrogels), have shown promise in providing a conducive microenvironment for cellular infiltration and favorable immune response. Nonetheless, there is a notably lacking in studies that demonstrate scarless regeneration solely through pore structure engineering. In this study, we demonstrate that optimizing micropore structure of injectable granular hydrogels via controlled liquid-liquid phase separation facilitates scarless wound healing. The building block particles are fabricated by precisely controlling the separation kinetics of two immiscible aqueous phases (gelling and porogenic) and timely arresting phase separation, to generate bicontinuous, hollow or closed porous structure. Employing a murine model, we reveal that the optimized pore structure significantly facilitates mature vascular network boosts pro-regenerative macrophage polarization (M2/M1) and CD4+/Foxp3+ regulatory T cells, culminating in scarless skin regeneration enriched with hair follicles. Moreover, our hydrogels outperform the clinical gold-standard collagen/proteoglycan scaffolds in a porcine model, showcasing superior cell infiltration, epidermal integration, and dermal regeneration. Micropore structure engineering of biomaterials presents a promising and biologics free pathway for tissue regeneration.

Tight orchestration of wound healing phase through metal-organic compounds

Cutaneous wound healing remains a common health problem. Metal-organic frameworks (MOFs) have emerged as an advanced therapeutic platform for promoted wound healing. However, there is a lack of MOF particles possessing excellent stability, biocompatibility, and reactive oxygen species (ROS) scavenging ability for tight orchestration of wound healing. Herein, we synthetize therapeutic MOF particles named PgC3Zn and employ them as skin sprays for wound repair. At the inflammatory stage, the pH- and ROS-responsive Zn2+ release of PgC3Zn alleviates oxidative stress and exerts antibacterial and anti-inflammatory efficacy. During the proliferation stage, PgC3Zn promote the migration and proliferation of fibroblasts, the re-epithelialization of keratinocytes, and the angiogenesis of endothelial cells. During the remodeling stage, PgC3Zn effectively facilitate the wound closure and collagen deposition. Moreover, multiple endogenous growth factors have been identified to contribute to the wound healing process. Importantly, PgC3Zn exhibit excellent biocompatibility and remarkably accelerate the healing process in both acute and infected rat full-thickness skin wound models in vivo. Consistently, transcriptomic data illustrate the multi-stage and multi-functional regulation effects of PgC3Zn in promoting wound healing. This study proposes versatile and biocompatible PgC3Zn MOF particles with potentials for enhancing the management of acute and infected skin wounds.

Rationally manipulating molecular planarity to improve molar absorptivity, NIR-II brightness, and photothermal effect for tumor phototheranostics

The secondary near-infrared region (NIR-II) fluorescence imaging-guided photothermal therapy (PTT) offers a noninvasive and light-controllable treatment option for deep-seated cancers. However, the development of NIR-II photothermal agents (NIR-II PTAs) that possess the desired properties of high molar absorption coefficient (ε), fluorescence quantum yield (QY), and photothermal conversion efficiency (PCE) remain a challenge due to the contradiction between radiative and nonradiative processes. Herein, we propose a novel side-chain heteroatom substitution engineering strategy to simultaneously enhance ε, QY, and PCE by modifying the molecular planarity. Remarkably, by increasing the number of oxygen atoms in the alkyl chains from DTIC, DO1TIC, to DO2TIC, the D-A interaction was enhanced and the molecular planarity was optimized. Theoretical calculations indicated that DO2TIC has a smaller energy gap and closer packing, which may lead to effective regulation of radiative and nonradiative transition processes. Notably, we achieved the excellent ε value of 2.61 × 105 M-1 cm-1 for the NIR-II PTA from DO2TIC, which is attributed to the enhanced molecular planarity. This value surpasses that of most previously developed NIR-II PTAs, resulting in boosted QY and PCE in its nanoparticle state. With these advantages, DO2TIC NPs demonstrated high signal-to-background ratio (SBR = 13.50) imaging of the vascular system and NIR-II imaging-guided PTT for effective tumor elimination using a 1064 nm laser. This study provides a new perspective for developing versatile NIR-II excited phototheranostic systems, enabling potent bioimaging and cancer therapy.

Recent advances in smart hydrogels derived from polysaccharides and their applications for wound dressing and healing

Owing to their inherent biocompatibility and biodegradability, hydrogels derived from polysaccharides have emerged as promising candidates for wound management. However, the complex nature of wound healing often requires the development of smart hydrogels---intelligent materials capable of responding dynamically to specific physical or chemical stimuli. Over the past decade, an increasing number of stimuli-responsive polysaccharide-based hydrogels have been developed to treat various types of wounds. While a range of hydrogel types and their versatile functions for wound management have been discussed in the literature, there is still a need for a review of the crosslinking strategies used to create smart hydrogels from polysaccharides. This review provides a comprehensive overview of how stimuli-responsive hydrogels can be designed and made using five key polysaccharides: chitosan, hyaluronic acid, alginate, dextran, and cellulose. Various methods, such as chemical crosslinking, dynamic crosslinking, and physical crosslinking, which are used to form networks within these hydrogels, ultimately determine their ability to respond to stimuli, have been explored. This article further looks at different polysaccharide-based hydrogel wound dressings that can respond to factors such as reactive oxygen species, temperature, pH, glucose, light, and ultrasound in the wound environment and discusses how these responses can enhance wound healing. Finally, this review provides insights into how stimuli-responsive polysaccharide-based hydrogels can be developed further as advanced wound dressings in the future.

Large-scale synthesis of non-ionic bismuth chelate for computed tomography imaging in vivo

High atomic number elements-based X-ray computed tomography (CT) contrast agents offer a promising solution to address the inherent deficiencies of FDA-approved iodine contrast agents. However, they face substantial challenges in balancing imaging performance, safety, and large-scale production for clinical translation. Herein, inspired by the history of clinical gadolinium- and iodine-based contrast agents, we report a large-scale approach for synthesizing non-ionic bismuth (Bi) chelate for high-performance CT imaging in vivo. Bi-HPDO3A can be easily obtained from low-cost precursor within 4 steps at 6 g-scale. The non-ionic macrocyclic structure endows it with low osmolality, low viscosity, high stability, good renal clearable capability and biocompatibility. Additionally, Bi-HPDO3A realizes superior imaging performance across various in vivo applications, including gastrointestinal imaging, renal imaging, and computed tomography angiography (CTA). Especially, Bi-HPDO3A exhibits superior spectral imaging capability owing to the high K-edge of element Bi, achieving metal artifact-free CTA in vivo. The proposed Bi-HPDO3A that balances overall performance can serve as a high-performance CT contrast agent with potential for clinical translation.

Nanodomains and the topography of water: An X-ray revelation of tuneable self-assembly in insoluble films

Long, straight chain saturated fatty acids form homogeneous, featureless monolayers on a supramolecular length scale at the water-air interface. In contrast, a naturally occurring saturated branched fatty acid, 18-methyl eicosanoic acid (18-MEA) has been observed to form three-dimensional domains of size 20-80 nm, using a combination of Langmuir trough, Atomic Force Microscopy (AFM) images of the deposited monolayers, and Neutron reflectometry (NR) and X-Ray reflectometry (XRR). It is hypothesized that these domains result from the curvature of the water surface induced by the steric constraints of the methyl branch. Accordingly, in this work, we investigate in situ the structure of such films using Grazing Incidence Small Angle X-ray Scattering and Diffraction (GISAXS and GIXD). The branched fatty acids indeed form curved nanodomains as revealed by their two-dimensional scattering pattern whereas straight chain fatty acids form the expected featureless film, with no GISAXS scattering peaks. Mixed monolayers consisting of 18-MEA and eicosanoic acid (EA) display a phase transition in the structure from hexagonally packed at high 18-MEA ratio to structures with one-dimensional translational ordering (aligned stripes) for 50:50 mol% and lower ratios. Moreover, the GIXD patterns of monolayers containing 18-MEA display a peak with curved distribution of intensity, indicating a continuous distribution of collective molecular orientations, consistent with the local curvature of the water surface. Finally, we report on an unusual double peak phenomenon in the GISAXS data that is interpreted as being due to a hexagonal packing of elliptical domains - i.e. with two characteristic dimensions. Synchrotron X-Ray scattering experiments have thus unambiguously confirmed the self-assembly, out of plane, "cobbling" of the water interface by these branched structures.

In-vivo spectral recomposition of sunlight with glycosylated aggregation-induced emission antennas for boosting photosynthesis

Efficient solar energy capture is crucial for boosting photosynthesis, but excess energy can lead to photodamage. Here, we developed a glycosylated antenna molecule TPyGal (4-(4-(2,2-bis(4-methoxyphenyl)-1-phenylvinyl)styryl)-1-(2-((3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl)oxy)ethyl)pyridin-1-ium bromide) featuring a robust electron donor-acceptor structure and aggregation-induced emission property, for in vivo spectral recomposition of solar energy to optimize photosynthesis. TPyGal demonstrated strong assembly with the cell membrane of photosynthetic algae and exhibited low biotoxicity. As a biocompatible membrane antenna, TPyGal efficiently redistributed ultraviolet and blue light into red light on the algal cell membrane. Such intracellular spectral recomposition could reduce energy waste and mitigate photodamage, which significantly improved light utilization. Consequently, algae assembled with TPyGal showed a substantial increase in photosynthetic rates and biomass production. Furthermore, TPyGal acted as both a fertilizer and an artificial antenna, effectively promoting the photosynthesis and growth of higher plants, such as mung bean sprouts. This work provides a promising strategy for efficient solar energy conversion and photosynthesis enhancement.

In situ construction of Mn3O4 cocatalyst on sodium poly(heptazine imides) for enhanced photocatalytic reduction of water and synergetic oxidation of amines

Photocatalytic hydrogen production utilizing solar energy provides a pivotal strategy for realizing a carbon-neutral society. Cocatalyst-modified semiconductor materials have emerged as promising candidates for photocatalytic applications due to their ability to facilitate the spatial separation and directional migration of photogenerated electron-hole pairs. Nevertheless, those systems often face challenges such as intricate preparation procedures and issues with non-compact recombination. Herein, we report a one-pot thermal treatment approach for synthesizing a composite of Mn3O4 nanoparticles and sodium poly(heptazine imides) (Na-PHI). Mn3O4 nanoparticles were in situ generated and embedded within the Na-PHI matrix during the sintering process. The resulted photocatalyst demonstrated significantly enhanced photoinduced charge separation efficiency, exhibiting approximately 6-fold and 3-fold improvements compared to pristine Mn3O4 and Na-PHI, respectively. The photocatalytic hydrogen evolution rate reached 14 μmol h-1, nearly 9 times that of Na-PHI (1.6 μmol h-1) in the aqueous solution of benzylamine (BA) under visible light illumination (780 nm ≥ λ ≥ 420 nm). Furthermore, the optimized Mn3O4-Na-PHI sample (Mn-Na-PHI) displayed a remarkably high photocatalytic hydrogen generation rate alongside the synchronous photo-oxidative coupling of aliphatic and aromatic amine under visible light. This work underscores the potential for rational design and synthesis of novel Na-PHI-based functional composites for sustainable energy applications.

In-situ characterization of microgel monolayers: Controlling isostructural phase transitions for homogeneous crystal drying patterns

The self-assembly of microgels at fluid interfaces and transfer to solid substrates has proven valuable in fields like photonics, plasmonics, and nanofabrication. However, this process is constrained by the isostructural phase transition (IPT) that occurs under sufficiently high compression, disrupting the monolayer order. Understanding the mechanisms driving IPT is crucial to extend their applicability to a wider range of interparticle distances. We tackle this problem by studying the monolayer conformation via in-situ microscopy at the interface. We monitored the microgel monolayer throughout the different stages of the deposition onto a solid substrate. We found that neither the compression at the interface nor the capillary forces arising from the receding meniscus during the deposition triggered the IPT. In fact, the still wet deposited monolayers do not exhibit IPT regardless of the compression of the monolayer. Instead, the IPT occurs during the drying of the wet deposited monolayers, particularly when the capillary force overcomes the adhesion force. Additionally, we found a new mechanism to modulate the interparticle distance by light-induced Marangoni forces. Instead, IPT arises from capillary forces generated during the drying of the water film after the monolayer is transferred. We propose a theoretical model to estimate the adhesion force between the microgels and the substrate based on the compression curve of the monolayer. Furthermore, we suggest a novel method combining a Langmuir-Schaefer deposition with supercritical drying to fully prevent the IPT, resulting also in a new tool to study an otherwise inaccessible regime with highly compressed monolayers. Our findings advance the understanding of soft colloidal self-assembly at fluid interfaces and expand their applications, enabling the creation of larger substrates with highly ordered self-assembled microgel monolayers with tunable interparticle distance.

High-performance sodium-ion batteries using Na5PV2Mo10O40 modified reduced graphene oxide (rGO) composite materials induced by imidazole ionic liquids

Sodium-ion batteries (SIBs) have gained increasing attention as a promising alternative to lithium-ion batteries, owing to the abundance and low cost of sodium. However, despite these advantages, the performance of SIBs is hindered by the larger ionic radius of sodium, which not only reduces ion migration rates but also significantly decreases the specific capacity. To address this challenge, the present study explores the synthesis of Na5PV2Mo10O40 (PV2Mo10)-modified reduced graphene oxide (rGO) composites by employing imidazole ionic liquid (IL) as electrostatic attraction agent, this approach not only prevents the aggregation of polyoxometalates (POMs) but also increases the interlayer distance of rGO, improving the battery's specific capacity and enhancing the diffusion rate of Na+ ions. Experimental results indicate that the PV2Mo10-rGO-IL hybrid material exhibits exceptional electrochemical properties, characterized by significantly improved conductivity and an impressive specific capacity of 290mAh g-1 while achieving nearly 100 % Coulombic efficiency over 900 cycles. Furthermore, theoretical calculations reveal that the incorporation of POMs effectively reduces the electrode impedance of rGO and enhances the structural stability of POMs during cycling. This study opens up new avenues for the design of high-performance sodium ion batteries based on POMs.

Boosting selective CO2 reduction via strong spin-spin coupling on dual-atom spin-catalysts

Achieving high selectivity in electrochemical conversion of carbon dioxide (CO2) into valuable products remains a significant challenge. This study investigates the influence of spin states on dual-atom catalysts within two-dimensional metal-organic frameworks (2D-MOFs) and zero-dimensional molecular metal complexes (0D-MMCs), emphasizing their role in the selective electrocatalytic reduction of CO2. Utilizing first-principles calculations, we systematically evaluate dual-atom spin-catalysts (DASCs) TM2S4(NH)2(C6H4)2 0D-MMC and TM2S4(NH)2C4 2D-MOF for CO2 reduction reactions (CO2RR) across various spin states: antiferromagnetic (AFM), ferromagnetic (FM), and non-magnetic (NM). Our analysis confirms that, beyond successfully designing and screening highly active catalysts, the selectivity for various C1 products in CO2 reduction can be readily adjusted by DASCs via spin-spin coupling. Specifically, Mn2 and Fe2 2D-MOF DASCs with an AFM ground state are more inclined to produce formic acid, while their FM counterparts favor the formation of methane, surpassing formic acid among others. Additionally, we demonstrate that 0D-MMCs, as molecular units of 2D-MOFs, achieve comparable catalytic performance. Combining theoretical insights with machine learning highlights the crucial role of electronic and geometric descriptors in the catalytic performance. Our work establishes the correlation between spin-spin coupling and highly selective CO2 reduction in DASCs, offering an effective strategy for designing tunable and efficient electrocatalysts.

Dual temperature/mechanical-responsive photonic crystal ionogels assembled by soft nanogels

In this paper, inspired by biological skin, photonic crystal ionogels with tuning stretching response and temperature response were cleverly constructed. By the method of emulsion precipitation polymerization, we firstly fabricated a series of nanogels composed of poly(N-isopropylacrylamide-co-N-(1-naphthyl) maleic acid) (P(NIPAM-co-NNMA)). The photonic crystals were constructed through the self-assembly of P(NIPAM-co-NNMA) nanogels in a mixing solvent of water and ionic liquid (IL) 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIM Otf). The phase transition temperature (Tp) of the nanogels was increased with an increase of the ionic liquid BMIM Otf in the mixing solvent. The photonic crystal ionogels (PIGs) were prepared by locking the photonic crystals via another polymer networks of poly (N,N-dimethylacrylamide) (PDMA). With decreasing ionic liquid, the structural color gradually becomes bright but the stretching strength and the elongation decreased. As the ratio of IL to water decreased to 2.9:1, the photonic crystal ionogels looked bright and the ionogels demonstrated a good elongation at break nearing 364%. As the ionogels were stretched, the structural color exhibited a blue-shift. Very interestingly, the structural color of the 100% stretching-ionogels was still stable as the content of PDMA was in a range of 15 wt% to 17 wt%. Furthermore, the composite device formed by integrating the temperature-responsive photonic crystal ionogels with carbon nanotubes (PIG-CNTs) films not only demonstrates electro-thermal conversion performance but also the ability to directly capture visual signals. This study provides a general and enlightening design strategy for the construction of high performance of photonic crystal ionogels.

VxOy quantum dot-enhanced nitrogen-sulfur dual-doped hierarchical porous carbon electrodes from waste eggshell membranes for advanced flexible supercapacitors

The weathering of rocks naturally creates abundant pore structures on their surfaces. Drawing inspiration from this, we present a simple yet effective approach-combining hydrothermal carbonization and pyrolysis carbonization-to synthesize multivalent vanadium oxide (VxOy) quantum dot-enhanced nitrogen- and sulfur-doped hierarchical porous carbon materials derived from waste biomass of eggshell membranes. These carbon materials, termed VxOy-S@CESM, are used as electrodes for supercapacitors. The results demonstrate that the multivalent VxOy quantum dot structure effectively increases the active sites and enhances the pseudocapacitance, particularly the pseudocapacitance associated with V4+ in the composites. The optimal VxOy-S@CESM sample achieves a capacitance of 355 F/g at 0.5 A/g. The flexible VxOy-S@CESM symmetrical supercapacitor retains more than 80 % of its capacity across various bending angles (0°-180°). It also exhibits a high energy density of 27.9 Wh kg-1 and a power density of 906 W kg-1. Density functional theory (DFT) calculations confirmed that the introduction of VxOy quantum dots significantly increases the adsorption energy of Na+ ions and induces polarization in the carbon materials. This quantum dot-enhanced carbon material design opens new avenues for the development of advanced energy storage materials.

Unveiling co-acting effects of potassium and hydroxide ions on carbon dioxide reduction reaction selectivity

The interfacial microenvironment plays a crucial role in influencing the absorption of important reaction intermediates and the resulting selectivity for carbon dioxide reduction reaction (CO2RR) (Xu et al., 2022) [1]. In this paper, the influence effects of potassium and hydroxide ions on CO2RR of Cu-based catalysts are comprehensively investigated using in-situ Raman spectroscopy and theoretical calculation. The results showed that potassium ions improved the binding strength of CO adsorbates (COad) intermediates on active sites, which is conducive to C-C coupling or further reaction. The presence of hydroxyl adsorbates (OHad) changes the charge distribution on the catalyst surface and reduces the energy barrier of C-C coupling. However, the excessive OHad adsorption can occupy a large number of active sites, leading to a decrease in COad coverage. We unveiled that the combined co-acting effect of potassium ions and hydroxide ions co-regulated the COad adsorption energy and COad coverage on Cu-based catalysts, leading to the modulation of the products selectivity. This work provides new insights for understanding the effect of interfacial microenvironment on the catalytic performance of CO2RR catalytic systems.

Ion incorporation into cobalt(II)-organic framework for green and efficient synthesis of oxazolidinones via carbon dioxide fixation

Developing a green and efficient method for CO2 transformation is crucial for advancing carbon neutrality and effective resource utilization. Among the transformations, carboxylative cyclization of CO2 to produce oxazolidinones is an atom-economical reaction with valuable pharmaceutical applications. However, most catalytic systems often require high temperatures, organic solvents or show low efficiency. Herein, we report a novel anionic framework, {[NH2(CH3)2]2[Co3(L)3(µ3-O)]·0.37DMA }n (1), which can be synthesized on a gram scale and displays excellent stability. As a catalyst, compound 1 enables the carboxylative cyclization of propargylic amines with CO2 at 70 °C for 12 h under ambient pressure, and can be reused up to 10 times while maintaining structural stability. Given the relatively high temperature and extended reaction time required in the 1-catalytic system, Ag+ and Cu2+ ions are incorporated into the framework of compound 1 through cation exchange. The Ag+-incorporated composite 1-Ag(0.05) exhibits high catalytic efficiency under ambient temperature and CO2 pressure within 6 h without using solvent, and can be reused for at least five successive cycles. Control experiments and DFT calculations reveal that the synergistic interaction between Ag+, Co-framework and DBU is the key factor promoting the reaction. To our knowledge, this study provides the first comprehensive investigation into the impact of ion incorporation on the catalytic performance of a Co-based framework in the carboxylative cyclization of propargylic amines with CO2.

Unveiling the effects of conjugated gradient bridges: Inducing intramolecular charge transfer significantly enhances nonlinear response

As an important π-conjugated bridge, (E)-2-styrylthiophene possesses excellent electronic transport and optical properties, showing great potential in nonlinear optical (NLO) applications. In order to investigate the influence of different donor units on (E)-2-styrylthiophene in NLO, we synthesized three thiophene-based D-π-A conjugates with dicyanoacetylene as the acceptor and different donors (MS, PS, FS) by inducing intramolecular charge transfer (ICT). Their third-order nonlinear absorption was studied using Z-scan experiments and transient absorption spectroscopy. Due to the significant ICT, MS exhibited the highest nonlinear absorption coefficient (β = 1.5 × 10-9 m W-1) and effective third order refractive index (n2 = -12 × 10-17 m2 W-1). Taking the strongest performing MS molecule as an example, we analyzed four types of conjugated bridges through theoretical calculations, which indicated that (E)-2-styrylthiophene has the strongest dipole moment difference (Δμ = 34.73 D). Finally, transient absorption (TA) spectroscopy revealed that the nonlinear absorption of these molecules is primarily caused by reverse saturable absorption (RSA).

Roles of ESIPT and TICT in the photophysical process of a Zn2+ sensor: Ratiometric or turn-on

The cis-trans isomerization of the C=N bond is generally believed to induce quenching in molecules containing a Schiff base. These molecules typically serve as turn-on sensors for cations, with only a few acting as ratiometric sensors. This study presents a comprehensive investigation into the photophysical processes of an unusual ratiometric sensor for Zn2+ based on Schiff base, utilizing density-functional theory (DFT) and time-dependent DFT (TDDFT). By examining the potential energy surface (PES) of the S1 state, multiple dynamic processes including excited state intramolecular proton transfer (ESIPT), bond twisting, and C=N isomerization were analyzed. Energy barriers and rate constants for these processes were obtained and compared to evaluate their likelihood of occurrence. It was found that C=N isomerization can only take place after an ESIPT process and leads to a non-emissive twisted intramolecular charge transfer (TICT) state, turning the probe into a turn-on sensor. However, the electron-withdrawing nature of the cyano group induces strong intramolecular charge transfer during photoexcitation and leaves the Schiff base unexcited. As a result, the ESIPT process is unfavorable, and the subsequent C=N isomerization is prevented, making the probe a ratiometric sensor. Moreover, two additional sensors with electron-donating and electron-withdrawing groups were designed, and their photophysical processes were studied, providing further support for the proposed theory.

Gold nanobipyramids/MXene@PVDF membrane material for SERS detection and sensitive determination of fluorescent dyes

Au BPs/MXene mixtures were composited with PVDF membranes by vacuum filtration, which enabled the sensitive detection. It combined electromagnetic mechanism and chemical mechanism to achieve a synergistic enhancement of the detection, resulting in a good stability of the SERS substrate. With fluorescent dyes including rhodamine 6G and methylene blue as templates for the SERS sensor, the SERS substrate possessed high sensitivity and reproducibility on account of the strong interactions between the dye molecules and the Au BPs/MXene. In addition, the photochemical performance of the composite membrane material for rhodamine 6G and methylene blue was investigated, which demonstrated the potential of AuBPs/MXene@PVDF membrane for photochemical applications. The study of the SERS detection and photochemical degradation performance of the composite membrane material in different water sources demonstrated that the excellent testing capability of the AuBPs/MXene@PVDF membrane material can be used for reliable and highly sensitive monitoring and application in water environment analysis.

A dual-reactivity-based surface-enhanced Raman spectroscopy nanosensor for the simultaneous imaging of hypochlorite and nitric oxide in living cells

A surface-enhanced Raman spectroscopy (SERS) nanosensor with dual-reactivity is developed for the simultaneous imaging of hypochlorite (ClO-) and nitric oxide (NO) in living cells. Utilizing the specific reactions between functional molecules and ClO- and NO, respectively, the 2-mercapto-4-methoxy-phenol (2-MP) and o-phenylenediamine (OPD) molecules are synchronously assembled on the surface of gold nanoparticles to fabricate the dual-function nanosensors. The advantages of SERS technology, narrow peaks for spectral multiplexing and fingerprint information, further facilitate the simultaneous detection of ClO- and NO. The prepared nanosensors achieve a highly sensitive and selective measurement of ClO- and NO with a limit of detection of 0.054 μM and 0.46 μM, respectively. Furthermore, the SERS nanosensors enable the simultaneous visualization of ClO- and NO in the single living cell, which opens up the prospects to investigate the ClO-- and NO-involved physiological and pathological events.

Elucidating the suppressive mechanism of four inhibitors on VP39 and unique conformational changes with protein in mode 2

Methyltransferase VP39 is an important target for the treatment of monkeypox, and inhibition of VP39 can effectively suppresses the transcription and translation of early viral RNA. However, very few inhibitors have been designed against VP39 and other viral MTases. In this work, four inhibitors (SFG, TO507, TO427 and TO1119) were used to investigate the binding mechanism with VP39. Moreover, VP39 has different modes of existence, but we do not understand the interaction mechanism of the complex system formed by the inhibitors with different modes of VP39, so we performed 1000 ns molecular dynamics simulations of the complexes formed by four inhibitors with VP39 in mode 1 and mode 2, and performed energy calculation and conformational analysis. The results of binding free energy showed that in the inhibitors-VP39 (mode 1) systems, TO507 and TO427 had a strong inhibitory effect on VP39, and residues ASP95, ARG97, PHE115 and VAL139 played important roles in the binding process of all four systems. Surprisingly, in the inhibitors-VP39 (mode 2) systems, four inhibitors underwent a large conformational change, with the amino acid moieties of the inhibitors undergoing a nearly 90° folding. And this change reduced the inhibitory effect of the inhibitors on VP39. In addition, the inhibitor TO507 also had a good inhibition effect on nsp14 of SARS-CoV-2 and NS5 of Zika virus. Therefore, this study suggests new ideas for the design and improvement of pan-MTase inhibitors, which are important for the treatment of pandemic infectious diseases, such as monkeypox and SARS-CoV-2.

High stable electrochemical response of atmosphere-modulated jujube cake-like Co@Co3O4 complexes to the tumor marker CD44

CD44 is a complex transmembrane glycoprotein that exists in multiple molecular forms and aberrant expression of CD44 is associated with tumorigenesis and progression. CD44 is involved in the regulation of several important signaling pathways, including tumor proliferation, invasion, metastasis, and therapy resistance, and it is also regulated by a variety of cells, which is a common biomarker for cancer stem cells. Detection and quantification of CD44 can provide essential information useful for clinical cancer diagnosis. Electrochemical sensors are prominently used for the detection of cancer biomarkers due to their rapidity, robustness, ease of miniaturization, excellent sensitivity and selectivity. In this study, we synthesized two cobalt-based materials under different atmospheres by photochemical metal-organic deposition methods (PMOD) and thermal annealing treatments, and then built and optimized two cobalt-based sensors that produce responses to CD44. The results showed that the performance of HA-Co@Co3O4 (HCo@Co3O4) electrodes were superior to that of HA-CoO@Co3O4 (HCoO@Co3O4) in terms of detection limit, sensitivity and stability, the linear range was 1 × 10-5 to 1 × 103 ng mL-1 with a detection limit of 0.619 × 10-5ng mL-1, the trend of the test results was consistent with the conventional Elisa method. The effects of different annealing atmospheres on the electrochemical activity of cobalt oxide-based materials for the detection of CD44 were investigated, which provided an experimental and theoretical basis for the electrochemical detection of CD44 and other types of tumor markers by cobalt oxides. In biomedical detection, very low concentration detection is conducive to the monitoring of CD44 dynamic changes: low concentration of CD44 changes can be detected, which is conducive to the early detection of diseases. In addition, the outstanding detection limit indicates the high selectivity of the material for the target molecule in complex biological samples and the high stability in complex biological samples, it provides a detection basis for future clinical applications.

Co-consumption for plastics upcycling: A perspective

The growing plastics end-of-life crisis threatens ecosystems and human health globally. Microbial plastic degradation and upcycling have emerged as potential solutions to this complex challenge, but their industrial feasibility and limitations thereon have not been fully characterized. In this perspective paper, we review literature describing both plastic degradation and transformation of plastic monomers into value-added products by microbes. We aim to understand the current feasibility of combining these into a single, closed-loop process. Our analysis shows that microbial plastic degradation is currently the rate-limiting step to "closing the loop", with reported rates that are orders of magnitude lower than those of pathways to upcycle plastic degradation products. We further find that neither degradation nor upcycling have been demonstrated at rates sufficiently high to justify industrialization at present. As a potential way to address these limitations, we suggest more investigation into mixotrophic approaches, showing that those which leverage the unique properties of plastic degradation products such as ethylene glycol might improve rates sufficiently to motivate industrial process development.

Engineered cell membrane vesicles loaded with lysosomophilic drug for acute myeloid leukemia therapy via organ-cell-organelle cascade-targeting

Acute myeloid leukemia (AML) presents significant treatment challenges due to the severe toxicities and limited efficacy of conventional therapies, highlighting the urgency for innovative approaches. Organelle-targeting therapies offer a promising avenue to enhance therapeutic outcomes while minimizing adverse effects. Herein, inspired that primary AML cells are enriched with lysosomes and sensitive to lysosomophilic drugs (e.g., LLOMe), we developed a smart nanodrug (Cas-CMV@LM) including the engineered cell membrane vesicles (CMVs) nanocarrier and the encapsulated drug cargo LLOMe (LM). Briefly, the nanodrug with organ-cell-organelle cascade-targeting function could firstly home to the bone marrow guided by CMVs derived from CXCR4-overexpressing bone marrow mesenchymal stem cells (BMSC), subsequently target leukemia cells via CD33 and CD123 aptamers anchored on the vesicles, eventually precisely attack the lysosomes of leukemia cells. Consequently, Cas-CMV@LM specifically inhibited leukemia cell proliferation and triggered necroptosis in vitro. Importantly, the cascade-targeting nanodrug displayed high biosafety and significantly impeded leukemia progression in AML patient-derived xenograft (PDX) model. Collectively, this study provides a paradigm for precision leukemia treatment from the perspective of targeting organelle-lysosome.

Free-standing, flexible and conformable bilayered polymeric nanomembranes modified with gold nanomaterials as electronic skin sensors

Skin is a barrier that protects us against physical, chemical and biological agents. However, any damage to the skin can disrupt this barrier and therefore compromise its function leading to sometimes catastrophic consequences like sepsis. Thus, methods to detect early signs of infection are necessary. In this work, we have developed a straightforward method for producing 2D nanomembranes with regularly spaced 1D metallic nanostructures integrating sensing capabilities to pH and NADH (nicotinamide adenine dinucleotide), which are critical analytes revealing infection. To achieve this, we have successfully fabricated a bilayered nanomembrane combining a pH-responsive polyaniline (PANI) layer and a nanoperforated poly(lactic acid) (PLA) layer containing gold nanowires (Au NWs) as NADH sensing element. SEM, FTIR, Raman and AFM techniques revealed the formation of the bilayered PANI/PLA nanomembrane and the successful incorporation of the Au NWs inside the nanoperforations. The resulting bilayered nanomembrane showed significant flexibility and conformability onto different substrates due to the softness of the polymers and the ultrathin thickness with stiffness values similar to human skin. These nanomembranes also exhibited remarkable electrochemical sensing performance towards pH and NADH detection. Thus, the nanomembrane displayed linearity with good sensitivity (47 mV pH-1) in the critical pH range 4-10 and fast response time (10 s). On the other hand, PANI/PLA-Au nanomembranes also allowed the quantitative sensing of NADH with a limit of detection of 0.39 mM and a sensitivity of 1 µA cm-2 mM-1 in the concentration range 0-5 mM.

Probing the generation, reactivity, and kinetics of high-valent manganese-oxo phthalocyanines: Insights into oxidation mechanisms

In this study, manganese(IV)-oxo phthalocyanines [MnIV(Pc)(O)] (3) (Pc = phthalocyanine) were produced either through visible light photolysis of [MnIII(Pc)(ClO3)] or by chemical oxidation of [MnIII(Pc)Cl] (1) with iodobenzene diacetate. The manganese(IV)-oxo species under study include tetra-tert-butylphthalocyaine‑manganese(IV)-oxo (3a) and phthalocyanine‑manganese(IV)-oxo (3b). As anticipated, the generated 3 reacted with various organic substrates to yield the oxidized products and further proved to be a competent oxidant via an H218O isotope labeling experiment. The kinetics of oxygen atom transfer (OAT) reactions for these generated 3 species with a range of substrates were examined in CH3CN solutions unless other specified. Overall, the second-order rate constants under pseudo-first-order conditions for 3a and 3b with the same substrates display similar modest reactivity, with the nature of the substrate playing a major role in influencing the reactivity of species 3. The phenol substrates, in particular, reacted the fastest. Of note, second-order rate constants determined for thioanisoles are comparable to those of alkene epoxidations and activated CH bond oxidations. Conventional Hammett analyses of rate constants for substituted styrenes revealed a linear correlation with the σ constant, indicating minimal charge developed at the transition state during the oxidation process. Additionally, the competition product studies and the Hammett correlation analysis further suggested that the manganese(IV)-oxo species observed in those kinetic studies are unlikely to serve as the primary oxidant for the epoxidation reactions catalyzed by manganese(III) phthalocyanine with PhI(OAc)2.

Simulation of absorption spectra of native and unfolded proteins

Protein concentrations are routinely determined using the absorbance measured at 280 nm and Beer-Lambert's law. However, traditional single-wavelength approaches may be inferior to a multi-wavelength analysis of complete spectra given the larger amount of data that can be processed. Hence, the current study was aimed at simulating protein UV spectra (from 250 to 350 nm) with a view to more accurately estimate protein concentrations. We demonstrate that the spectra of unfolded proteins are well-simulated using primary sequence data and the wavelength-dependent molar absorption coefficients of l-cystine, l-phenylalanine, N-acetyl-l-tyrosinamide and N-acetyl-l-tryptophanamide (the latter two serving as L-Tyr and L-Trp model compounds). Alternatively, simulations can be performed with the coefficients of the Tyr and Trp mimics replaced by a pseudo-Voigt (pV) function, which mathematically fully describes the spectra of these model compounds. Furthermore, a pV function, generated from the analysis of the spectra of 14 proteins, can be utilized to simulate the spectral contributions of Tyr and Trp in native proteins with a reasonable degree of accuracy. A Microsoft Excel-based multi-wavelength fitting routine can be employed to simulate the spectra of proteins and compare them with those experimentally recorded, thereby facilitating the determination of protein concentrations.

Advances in nanoplatform-based multimodal combination therapy activating STING pathway for enhanced anti-tumor immunotherapy

Activation of the cyclic GMP-AMP synthase(cGAS)-stimulator of interferon genes (STING) has great potential to promote antitumor immunity. As a major effector of the cell to sense and respond to the aberrant presence of cytoplasmic double-stranded DNA (dsDNA), inducing the expression and secretion of type I interferons (IFN) and STING, cGAS-STING signaling pathway establishes an effective natural immune response, which is one of the fundamental mechanisms of host defense in organisms. In addition to the release of heterologous DNA due to pathogen invasion and replication, mitochondrial damage and massive cell death can also cause abnormal leakage of the body's own dsDNA, which is then recognized by the DNA receptor cGAS and activates the cGAS-STING signaling pathway. However, small molecule STING agonists suffer from rapid excretion, low bioavailability, non-specificity and adverse effects, which limits their therapeutic efficacy and in vivo application. Various types of nano-delivery systems, on the other hand, make use of the different unique structures and surface modifications of nanoparticles to circumvent the defects of small molecule STING agonists such as fast metabolism and low bioavailability. Also, the nanoparticles are precisely directed to the focal site, with their own appropriate particle size combined with the characteristics of passive or active targeting. Herein, combined with the cGAS-STING pathway to activate the immune system and kill tumor tissues directly or indirectly, which help maximize the use of the functions of chemotherapy, photothermal therapy(PTT), chemodynamic therapy(CDT), and radiotherapy(RT). In this review, we will discuss the mechanism of action of the cGAS-STING pathway and introduce nanoparticle-mediated tumor combination therapy based on the STING pathway. Collectively, the effective multimodal nanoplatform, which can activate cGAS-STING pathway for enhanced anti-tumor immunotherapy, has promising avenue clinical applications for cancer treatment.

Design and characterization of porphyrin-based photosensitizing metalloproteins integrated with artificial metalloenzymes for photocatalytic hydrogen production

Hydrogen is regarded as a promising alternative to fossil fuels. A desirable method of its generation is via photocatalysis, combining photosensitizers and hydrogen-evolution catalysts in the presence of an electron donor. Inspired by natural photosynthesis, we designed photosensitizing artificial metalloproteins (ArMs) and integrated them with ArM-based catalysts for photocatalytic hydrogen production from water. Metal porphyrins based on protoporphyrin IX (PPIX) were employed as they are naturally abundant and are effective both as photosensitizers and hydrogen-evolution catalysts. Photosensitizing proteins were created by binding zinc (Zn)PPIX or ruthenium (Ru)PPIX to the haem acquisition system A from Pseudomonas aeruginosa (HasAp). The photosensitizer ArMs were combined with cobalt (Co)PPIX-myoglobin (Mb) or free CoPPIX as hydrogen evolution catalysts. We found that free CoPPIX could replace ZnPPIX or RuPPIX in HasAp, forming CoPPIX-HasAp or RuPPIX-CoPPIX-HasAp complexes with enhanced stability compared to CoPPIX-Mb. Photocatalytic hydrogen production was achieved upon irradiation at 435 nm (ZnPPIX) or 385 nm (RuPPIX), using methyl viologen as an electron carrier and triethanolamine as an electron donor. The ZnPPIX-HasAp/CoPPIX-HasAp system remained intact and active for approximately 42 h, while Ru-based systems that were excited by UV light, exhibited signs of protein cleavage upon prolonged irradiation. These results demonstrate the potential of integrating porphyrin-based ArMs for photosensitization and hydrogen evolution, with HasAp providing a robust scaffold for sustained photocatalytic activity.

Targeting m6A demethylase FTO to heal diabetic wounds with ROS-scavenging nanocolloidal hydrogels

Chronic diabetic wounds are a prevalent and severe complication of diabetes, contributing to higher rates of limb amputations and mortality. N6-methyladenosine (m6A) is a common RNA modification that has been shown to regulate tissue repair and regeneration. However, whether targeting m6A could effectively improve chronic diabetic wound healing remains largely unknown. Here, we found a significant reduction in mRNA m6A methylation levels within human diabetic foot ulcers, and the expression level of fat mass and obesity-associated protein (FTO) was significantly increased. We identified that m6A modifies the RNA of matrix Metalloproteinase 9 (MMP9), a key factor in diabetic wound healing, to regulate its expression. Importantly, we developed a ROS-scavenging nanocolloidal hydrogel loaded with an FTO inhibitor to increase the m6A level of MMP9 RNA in wounds. The hydrogel can effectively accelerate wound healing and skin appendage regeneration in streptozotocin-induced type I diabetic rats at day 14 (approximately 98 % compared to 76.98 % in the control group) and type II diabetic db/db mice at day 20 (approximately 93 % compared to 60 % in the control group). Overall, our findings indicate that targeting m6A with ROS-scavenging hydrogel loaded with FTO inhibitor may be an effective therapeutic strategy for diabetic wound healing.

In-Tip Nanoreactors for Simultaneous Proteolysis and Enrichment of Phosphorylated Peptides

Protein phosphorylation introduces negative charges on the hydroxyl groups of serine, threonine, and tyrosine residues, reducing the ionization efficiency of phosphorylated peptides. The low abundance of phosphorylated peptides often diminishes their detection using mass spectrometry. To enhance the identification of the low-abundance peptides, an enrichment step was often used, which complicated the high-throughput analysis of phosphorylated proteomes. In this study, we developed a titanium dioxide surface-modified macroporous silicon encapsulated micropipette tips, loaded with trypsin, to integrate rapid enzymatic protein hydrolysis with selective enrichment and extraction of phosphorylated peptides within a microfluidic enzyme reactor. This streamlined approach simplified the protein sample preparation process, combining enzymatic hydrolysis, selective enrichment and separation while maintaining high efficiency. The method enabled comprehensive analysis of complex cancer cell line samples in 1-2 h. Successful detection of phosphorylated peptides from protein mixtures was achieved using matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry. This application may provide the potential for high-throughput phosphoproteomics and advance the study of protein modifications.

Facile preparation of full-color room temperature phosphorescence metal-organic framework via covalent ligand decoration

The preparation of full-color room temperature phosphorescence (RTP) metal-organic frameworks (MOFs) is attractive but remains challenging. Herein, it is demonstrated that heavy atom-free cyclodextrin MOFs (CD-MOFs) with full-color and long-lived intrinsic RTP can be achieved by CD ligand decoration. Arylboronic acids with various π conjugations are covalently anchored by γ-CD, in return, the B─O covalent bonds and hydrogen bonds jointly stabilize the triplet excitons of the arylboronic acid chromophores, leading to the longest lifetime of up to ca. 1.42 s and full-color afterglows including blue, green, and red of the decorated γ-CD. These decorated γ-CD derivatives are then linked by potassium ions to form a body-centered cubic crystalline structure, namely full-color RTP CD-MOFs. The smart RTP CD-MOFs also show excitation wavelength-dependent afterglows due to the formation of various emissive species. The CD-MOFs together with the γ-CD ligands are successfully applied in advanced dynamic information encryption and anticounterfeiting. This success paves the way for the development of ecofriendly and practical full-color RTP MOFs.

Identification a novel syntaxin-like protein from silkworm Bombyx mori pathogen Nosema bombycis and characteristics its membrane fusion function

Pebrine is a serious disease of the silkworm, Bombyx mori, caused by the first identified microsporidium Nosema bombycis, which is an obligate parasitic single-celled eukaryote. The pathogen can spread both horizontally and vertically, severely affecting sericulture. SNARE proteins mainly mediate the transport of vesicles and membrane fusion, playing a key role in the biological processes. The microsporidium is known to have a well-developed membrane system, especially the polaroplast which occupies most of the volume of mature spores. In order to explore the function of microsporidian SNARE protein, the transcription and subcellular localization characteristics of a novel Syntaxin-like protein (NbSTX-like) from N. bombycis that had a conserved t-SNARE motif were analyzed. In the different development stages of N. bombycis, the NbSTX-like expressed in the nucleus of meronts, then transited to the cytoplasm in the sporonts, gradually gathered at the two ends of the sporoblasts, and finally concentrated at the polaroplast, posterior vacuole and plasma membrane region of mature spores. Interestingly, the rNbSTX-like protein could fuse liposomes to form large vesicular and tubular structures. The formation of sporoplasms was inhibited by the anti-NbSTX-like serum, implying that NbSTX-like protein participated in sporoplasm maturation. These findings laid a foundation for studying the function of SNARE proteins in microsporidia and provided new insights for the prevention and control of sericulture pathogens.

Conductive and flexible gold-coated polylactic acid nanofiber-based electrochemical aptasensor for monitoring cortisol level in sweat and saliva

Conductive nanofibers can exhibit excellent mechanical properties such as flexibility, elasticity, porosity, large surface area-to-volume ratio, etc making them suitable for a wide range of applications including biosensor development. Their large surface area provides more active sites for immobilization of large amount of bioreceptors enabling more interaction sites with the target analytes, enhancing sensitivity and detection capabilities. However, engineering conductive nanofibers with such excellent properties is challenging limiting their effective deployment for intended applications. In this research, we propose a novel approach for easy fabrication of highly conductive and flexible nanofiber leveraging the electrospinning, electroless deposition and have applied it to cortisol monitoring; a common biomarker for stress which is often quantified through enzyme-linked immunoassays using blood or saliva samples. By adopting the nanofiber sheet as a transducer for aptamer immobilization and cortisol sensing our developed biosensor was able to detect cortisol in buffer, artificial saliva, and artificial sweat within five minutes, from 10 pg/mL to 10 µg/mL (27.59 pM to 27.59 µM) with a low detection limit of 1 pg/ml (2.76 pM). The Au-coated PLA nanofiber-based electrochemical biosensor's flexibility allows for compact manufacturing, rendering it an optimal choice for integration into point-of-care testing and wearable systems.

Uniform phosphazene containing porous organic polymer microspheres for highly efficient and selective silver recovery

The efficient extraction of silver ions (Ag+) from Ag+-contaminated wastewater is crucial for resource recovery and environmental protection. However, the synthesis of adsorbents with high adsorption capacity and superior selectivity for Ag+ is a significant challenge. Herein, a series of phosphazene-based porous organic polymers (POPs) microspheres with exceptional selectivity and adsorption capacity for Ag+ were rationally designed using phosphazene and aromatic amines. Notably, variations in the types of precursors induced the formation of a microsphere-like morphology with precisely controlled surface smoothness. Considering the advantages of abundant heteroatom active sites, surface charge properties and microsphere-like morphology, the synthesised networks exhibited an exceptional Ag+ adsorption capacity of 818.3 mg/g in aqueous solution at 45 °C, showcasing remarkable selectivity (selectivity coefficient (Kα) 3.39 × 105) and an ultrafast adsorption rate, adsorbing Ag+ in just 5 min. These superior adsorption characteristics surpassed those of most reported POPs. Theoretical simulations further revealed that key structural motifs, particularly phosphazene units, played a critical role in enhancing Ag+ adsorption. This study proposes a promising strategy for the efficient recovery of Ag from wastewater using high-performance porous adsorbents.

Unveiling the toxicity of micro-nanoplastics: A systematic exploration of understanding environmental and health implications

The surge in plastic production has spurred a global crisis as plastic pollution intensifies, with microplastics and nanoplastics emerging as notable environmental threats. Due to their miniature size, these particles are ubiquitous across ecosystems and pose severe hazards as they are ingested and bioaccumulate within organisms. Although global plastic production has reached an alarming 400.3 MTs, recycling efforts remain limited, with only 18.5 MTs being recycled. Currently, out of the total plastic waste, 49.6 % is converted into energy, 27 % is recycled, and 23.5 % is recovered as material, indicating a need for better waste management practices to combat the escalating pollution levels. Research studies on micro-nanoplastics have primarily concentrated on their environmental presence and laboratory-based toxicity studies. This review critically examines the sources and detection methods for micro-nanoplastics, emphasising their toxicological effects and ecological impacts. Organisms like zebrafish and rats serve as key models for studying these particle's bioaccumulative potential, showcasing adverse effects that extend to DNA damage, oxidative stress, and cellular apoptosis. Studies reveal that micro-nanoplastics can permeate biological barriers, including the blood-brain barrier, neurological imbalance, cardiac, respiratory, and dermatological disorders. These health risks, particularly relevant for humans, underscore the urgency for broader, real-world studies beyond controlled laboratory conditions. Additionally, the review discusses innovative energy-harvesting technologies as sustainable alternatives for plastic waste utilisation, particularly valuable for energy-deficient regions. These strategies aim to simultaneously address energy demands and mitigate plastic waste. This approach aligns with global sustainability goals, providing a promising avenue for both pollution reduction and energy generation. The review calls for further research to enhance detection techniques, assess long-term environmental impacts, and explore sustainable solutions that integrate energy recovery with pollution mitigation, especially in regions most affected by both energy shortages and increased plastic waste.

Visualizing enterohepatic circulation in vivo by sensitive 19F MRI with a fluorinated ferrous chelate-based small molecule probe

Enterohepatic circulation (EHC) is a critical biological process for the normal regulation of many endogenous biomolecules and the increased retention of various exogenous substances. The status of EHC is closely related to the ordinary functioning of several digestive organs. However, it remains a challenge to achieve in vivo real-time visualization of this process. Herein, we rationally design and synthesize a ferrous chelate, DO3A-Fe(II)-9F, with high fluorine content and favorable water solubility for visualizing EHC via19F magnetic resonance imaging (MRI). The assessments on imaging performance reveal an 18-time increase in signal intensity compared to the fluorinated ligand alone. This probe's capability of entering EHC via the mediation of organic anion transporting polypeptides (OATPs) is validated with ex vivo bio-distribution analysis and in vivo uptake-blocking imaging experiments, which allows short-time sensitive 19F MRI of EHC in healthy mice. Additionally, we illustrate its capacity for clearly imaging tampered EHC in the mice with inflammatory bowel diseases (IBD), drug-induced liver injury (DILI) or orthotopic hepatocellular carcinoma (HCC). These results illustrate the promising potential of this probe for in vivo visualization of EHC under different conditions, especially disease conditions, which is beneficial for the study, diagnosis, or even stratification of various diseases.