Enzyme mimics based on self-assembled peptide functionalized with graphene oxide for polyethylene terephthalate degradation

The degradation of polyethylene terephthalate (PET) has garnered notable attention owing to its widespread accumulation and the challenges associated with its breakdown. Herein, the enzyme mimics with PET-hydrolytic activity were developed by combining peptide nanofibers with graphene oxide (GO). Inspired by native enzymes, we designed self-assembled peptides that included active amino acids (serine, histidine, aspartate and tryptophan) and different hydrophobic amino acids, with a 9-fluorenylmethoxycarbonyl group at the N-terminus. Our comparison of hydrophobic amino acids revealed that their content not only influenced the higher-order assembly of peptide but also affected molecular conformation and PET degradation ability. By co-assembling two peptides with catalytic and binding sites in a 1:1 ratio, a more effective active enzyme mimic was constructed which was owning to the cooperative interactions among the active amino acids; in addition, hydrogen bonds and π-π stacking interactions were the main forces in enhancing catalytic effects. To further improve PET-hydrolytic ability, the co-assembled enzyme mimic was functionalised with GO through π-π stacking. This GO-peptide nanofiber hybrid exhibited increased PET-hydrolytic, as GO provided a hydrophobic microenvironment for substrate attraction and abundant carbon for facilitating proton transfer. The GO-peptide nanofiber hybrid as enzyme mimics will be a promising material for PET degradation.

Piezo-electronics: A paradigm for self-powered bioelectronics

Recent breakthroughs in electroactive piezo-biomaterials have driven significant progress towards the development of both, diagnostic and therapeutic purposes, enabling vital sign monitoring, such as heart rate, etc. while also supporting tissue regeneration. Bioelectronic medicine provides a promising method for controlling tissue and organ functions, with 'piezo-electronics' emphasizing the lasting role of electro-active piezo-biomaterials in self-powered devices. This article critically analyses a range of self-powered bioelectronic technologies, including wearable, implantable, regenerative, and cancer therapy applications. Piezoelectric nanogenerators (PENGs) are essential in wearable and implantable systems such as pressure and strain measurements, sensor for human-machine interface, self-powered pacemakers, deep brain stimulation, cochlear implant, tissue restoration and sustained drug delivery, controlled by electrical stimuli from PENGs etc. Regenerative bioelectronics play a key role in healing tissues, such as bone, neural, cardiac, tendon, ligament, skeletal muscle etc. using self-powered implants, which have ability to restore tissue functionality. Additionally, piezoelectric biomaterials are being utilized in cancer treatment, offering more targeted therapies with minimal side effects. Various cancerous tumors can be destroyed by reactive oxygen species (ROS), generated by piezo-biomaterials. Data science is also emerging as a crucial tool in optimizing self-powered bioelectronics, enhancing patient outcomes through data-driven strategies, and broadening the role of bioelectronic technologies in modern healthcare.

Recyclable methylcellulose-based reversibly cross-linked hydroplastics with excellent environmental stability for use in flexible printed circuit boards capable of safe disposal

Recyclable and degradable flexible bio-based plastics integrating high stability and efficient disintegration on demand are suitable for the fabrication of flexible printed circuit boards (FPCBs) capable of safe disposal. However, it is challenging to develop a facile and environmentally friendly method to fabricate such bio-based plastic substrates. Herein, recyclable and degradable reversibly cross-linked hydroplastics with high thermal stability and water stability used as the substrates of FPCBs are fabricated through the complexation of methylcellulose (MC) and tannic acid (TA) in pure water, followed by hot-pressing. Because of dynamic nanoconfinement phases, the bio-based hydroplastic (denoted as TA-MC) with a breaking strength of 109.6 MPa possesses a high storage modulus of 2.85 GPa at 180 °C. Even being immersed in water for 15 days, the hydroplastic still retains a high breaking strength of 40.4 MPa. Owing to the reversibility of hydrogen bonds, the hydroplastic can be recycled for several times. Moreover, FPCBs composed of flexible TA-MC substrates and 3D printed sensing components can be employed for reliable underwater detection. Electronic components can be easily separated from the FPCBs by dissolving TA-MC substrates in medical alcohol and residue polymer matrices, which degrade into non-toxic substances in soil, can be safely discarded without polluting the environment.

Dual oxygen supply system of carbon dot-loaded microbubbles with acoustic cavitation for enhanced sonodynamic therapy in diabetic wound healing

Diabetic wounds present significant treatment challenges due to their complex microenvironment, marked by persistent inflammation from bacterial infections, hypoxia caused by diabetic microangiopathy, and biofilm colonization. Sonodynamic therapy (SDT) offers potential for treating such wounds by targeting deep tissues with antibacterial effects, but its efficacy is limited by hypoxic conditions and biofilm barriers. To overcome these obstacles, we developed a novel approach using oxygen-carrying microbubbles loaded with Mn2+-doped carbon dots (MnCDs@O2MBs) to enhance SDT and disrupt biofilms. Through precursor screening and design, MnCDs are engineered to exhibit tailored properties of sonodynamic activity and enzyme-like catalytic capabilities. This system provides a dual oxygen supply for amplifying the SDT effects: MnCDs, serving as a sonosensitizer, also chemically convert excess H2O2 at infection sites into oxygen, while the O2MBs physically release oxygen through ultrasound-induced cavitation. The cavitation effect also disrupts biofilms, improving the delivery of sonosensitizers and boosting SDT efficacy. In a diabetic wound model, this strategy downregulated TLR, NF-κB, and TNF inflammatory pathways, reduced pro-inflammatory factor secretion, promoted angiogenesis, and accelerated wound healing, thereby acting as a promising treatment approach for diabetic wound healing.

A DNA-based nanorobot for targeting, hitchhiking, and regulating neutrophils to enhance sepsis therapy

Targeted regulation of neutrophils is an effective approach for treating neutrophil-driven inflammatory diseases, but challenges remain in minimizing off-target effects and extending drug half-life. A DNA-based nanorobot was developed to target neutrophils by using an N-acetyl Pro-Gly-Pro (Ac-PGP) peptide to specifically bind to the C-X-C motif of chemokine receptor 2 (CXCR2) on neutrophil membranes. This robot (a tetrahedral framework nucleic acid modified with Ac-PGP, APT) identified and hitchhiked neutrophils to accumulate at inflammatory sites and prolong its half-lives, whilst also was internalized to influence the neutrophil cell cycle and maturation process to regulate oxidative stress, inflammation, migration, and recruitment in both in vivo and in vitro inflammation experiments. Consequently, the tissue damage caused by sepsis was greatly reduced. This novel neutrophil-based nanorobot highlights the high precision of targeting and regulating neutrophils, and presents a potential strategy for treating multiple neutrophil-driven diseases.

Ultrasensitive detection of tetracycline using the disruption of crosslink-enhanced emission and inner-filter effect-induced phosphorescence quenching of carbonized polymer dots

Accumulation of tetracycline (TC) in the environment and food may lead to potential health risks and the emergence of antibiotic-resistant bacteria. To meet the demand for sensitivity, ease of use, and portability in detecting TCs, we fabricated a green phosphorescent film consisting of crosslinked polymer-integrated carbon dots (named carbonized polymer dots, CPD) and polyvinyl alcohol (PVA) polymers for ultrasensitive sensing of TCs via the inner filter effect-mediated phosphorescence quenching and the disruption of the crosslink-enhanced emission (CEE) effect by TC. To create polymer structures on the carbon dots for interaction with PVA, CPDs were synthesized via low-temperature hydrothermal treatment using citric acid and cysteine. Compared to products with oxidized sulfur or no sulfur doping, the incorporation of nitrogen and sulfur in CPDs was found to effectively facilitate intersystem crossing, significantly enhancing phosphorescence. By measuring the phosphorescence properties of compounds inside and outside the dialysis bag at different dialysis times, we confirmed that crosslinking interactions between CPD and PVA polymers can create a rigid environment to amplify the phosphorescence of sub-luminophores (e.g., hydroxyl, carboxyl, and amino groups) through the CEE effect. These features make the CPD/PVA film an effective tool for phosphorescence turn-off detection of TC, offering a wide linear detection range (1 nM-1 mM), a low limit of detection (0.7 nM), and good selectivity over potential interfering substances, such as metal ions, amino acids, fatty acids, and lactose. Our finding indicates that the TC-triggered phosphorescence quenching of the CPD/PVA film originates from TC-mediated IFE effect and TC-disrupted CEE effect. The CPD/PVA film was shown to establish a linear calibration curve to quantify TC in drinking water and milk samples with good recoveries (84 %-120 %).

DNAzyme@MOF breaking pH limitation for the detection of dopamine in the interstitial fluid

The level of dopamine (DA) in the human body has a certain correlation with neurological diseases. However, most detection methods of DA are complex and expensive. In this study, laccase-like DNAzyme@MOF with improved pH stability was successfully prepared. DNAzyme@MOF could catalyze the chromogenic substrate to change the color of the solution for the detection of DA in ISF. The addition of DNAzyme made DNAzyme@MOF possess higher stability and enzyme-like activity. The operation process was simple, rapid, and intuitive. In addition, the in vivo DA content in skin interstitial fluid (ISF) was analyzed by an off-line method. The swelling hydrogel microneedles (MNs) were prepared to extract skin ISF. DA in skin ISF was recovered and detected by laccase-like DNAzyme@MOF. This study realized the minimally invasive detection of DA. The proposed detection method of biomarkers in ISF based on DNAzyme@MOF would provide a new dimension towards the future development for the detection of other biomarkers in ISF.

Catalytic hairpin assembly-and-cyclization aptasensing for AND-logic detection of protein- and RNA-targets in ribonucleoprotein

Both immunological and molecular diagnostics are essential in disease control. However, due to the different technical routes, existing diagnostic tools mainly focus on either immunological or molecular targets at a time, resulting in restricted information for assessment. Herein, we report a DNA operational amplifier circuit for AND-logic analysis of nucleoprotein and RNA of SARS-CoV-2 ribonucleoprotein. The operator is realized using an aptamer-hairpin probe and a padlock-hairpin probe for nucleoprotein- and ligase-catalyzed hairpin assembly-and-cyclization (CHAC). Given approximately 1000 nucleoproteins per virion in coronavirus, a rolling circle amplification (RCA)-based preamplifier is applied to adjust the input bias by converting the target sequence into an aptamer-hairpin input for CHAC. After CHAC, cyclized padlock-hairpin probes trigger another round of RCA as a post-operator amplifier, producing amplicon coils that aggregate detection probe-modified magnetic nanoparticles. These stepwise homogeneous reaction processes are conducted in a single tube for optomagnetic sensing, offering detection limits of 0.07 ng/mL and 1.5 fM for the protein and the molecular targets of SARS-CoV-2, respectively. The stability, specificity, and accuracy of the circuit are validated by testing serum samples, salmon sperm samples, biased inputs, and 33 clinical nasopharyngeal swab specimens, demonstrating the practicability of simultaneously analyzing immunological and molecular targets for accurate diagnostics.

Analysis of molecular shapes and polarity in aniline derivatives for enhanced n-type carbon nanotubes based thermoelectrics and their application in self-powered electronics

Developing cost-effective and high-performance n-type thermoelectric (TE) materials is a significant challenge for their utilization in organic electronics. Clarifying the influence of molecular structure on TE properties is of utmost importance. In this work, the analysis on how the shape and polarity of organic molecules affect the thermoelectric performance of n-type composites based on single-walled carbon nanotubes (SWCNTs) is presented. A variety of aniline derivatives, characterized by low cost, diverse frameworks, tunable polarity, shallow HOMO levels are selected for tuning the n-type TE performance of SWCNTs. Notably, among these derivatives, p-phenylenediamine (PDA) with its compact planar structure and optimal polarity (Log P = -0.68), facilitated robust π-π interactions with SWCNTs. Additionally, the formation of hydrogen bonds between PDA and the solvent N-Methyl pyrrolidone (NMP) has been confirmed by theoretical calculations and 1H NMR results, further contributing to its superior performance. These interactions yielded a highest power factor of 745.47 ± 22.51 μW m-1 K-2, ranking among the highest reported for organic molecules/SWCNT materials to date. Taking advantage of its high performance, a TE device was fabricated, which exhibited an impressive temperature resolution of 0.07 K. Furthermore, a self-powered early warning system for battery overheating based on TE devices was firstly developed, which can effectively detect temperature variations in batteries, enabling precise overheating detection and explosion prevention.

Engineered covalent triazine framework inverse opal beads for enhanced photocatalytic carbon dioxide reduction

The development of highly ordered covalent triazine framework (CTF) materials with tailored structures is crucial for advancing functional material applications. Herein, we introduce a novel approach to fabricate covalent triazine framework inverse opal (CTF-IO) photonic crystal beads via a microfluidic-assisted assembly method and pore-confined polymerization. The polymerization process occurs within the interstitial voids of SiO2 nanoparticles (NPs) photonic crystals, where spatial confinement dictates the growth and arrangement of the CTF framework, resulting in a robust and precisely ordered inverse opal (IO) structure. The pore sizes, governed by the packing geometry of SiO2 NPs, are theoretically estimated to highlight the role of confinement in achieving structural fidelity. The unique slow-light effect of the CTF-IO structure enhances light absorption and charge transport, offering a versatile platform for light-driven CO2 conversion applications. As a demonstration, the optimized CTF-240 exhibit superior photocatalytic performance in CO2 reduction, achieving a yield of 118.69μmol g-1h-1 and a selectivity of 97.25 % without sacrificial agents or co-catalysts, significantly outperforming bulk CTF. This work underscores the potential of photonic crystal-guided framework design for diverse advanced applications, providing insights into the interplay between spatial confinement, structural engineering, and functional performance.

Copper-doped metal-organic framework-74 solid-state electrolytes for high performance all-solid-state sodium metal batteries

Rechargeable solid sodium metal batteries are attractive by virtue of their high energy density and cost-effectiveness. However, the inefficient Na+ transport dynamics and short lifepan hinder the practical application of solid sodium battery. Mg-MOF-74 nanomaterials have emerged as promising candidates for solid-state electrolytes because of their homogeneous porous structure and highly exposed metal sites. Nonetheless, the Na+ conductivity of pristine Mg-MOF-74 solid-state electrolytes is limited by sluggish ion movement. In this study, we successfully developed a series of bimetallic MOFs, specifically Cu2Mg8-MOF-74, by introducing copper doped metal to Mg-MOF-74. This metal-doped MOF electrolytes possess excellent Na+ transport and enhanced electrochemical stability in solid sodium metal batteries. The bimetallic sites of Cu2Mg8-MOF-74 deliver a superior capability to anchor anion ClO4- than single Mg sites in Mg-MOF-74, as validated by density functional theory calculation. Benefiting from that, Cu2Mg8-MOF-74 electrolytes substantially increase the ionic conductivity to 3.18 × 10-3 S cm-1 and the Na+ transference number to 0.86 at room temperature. Additionally, Na3V2(PO4)3|Cu2Mg8-MOF-74|Na cells demonstrated a high specific capacity of 104.5 mAh g-1 at 1C, with an impressive capacity retention rate of 91 %. Overall, this study delivers a viable method to optimize MOF materials for improved Na+ conductivity in future applications.

High performance of 5 V LiNi0.5Mn1.5O4 cathode materials synthesized from recycled Li2CO3 for sustainable Lithium-Ion batteries

Lithium has become a critical element in the modern era due to the emergence of lithium-ion battery (LIB) technologies as a mean to lessen the environmental burden created by the energy usage from conventional sources. In this study, Li2CO3 was obtained from spent LIBs using a hydrometallurgical method and sintered with Taylor Flow Reactor (TFR) synthesized Ni0.25Mn0.75(OH)2 precursor to synthesize high-voltage LiNi0.5Mn1.5O4 (R-LNMO) cathode material for the first time and conducted a series of tests and inspections for structure, morphology, electrochemical lithium cycling behaviour and its controlling factors, electronic conductivity, lithium ion diffusion characteristics and self-discharge behaviour. The results are benchmarked with C-LNMO synthesized through a similar processing but using Li2CO3 obtained from a commercial source. It was found that R-LNMO shows a higher crystal stability than the C-LNMO based on the in-situ oxygen gas-evolution results and lower angle shift in post-mortem X-ray diffraction (XRD) analysis after 500 cycles at 1C/1C, and it could be seen that both LNMO samples have good structural reversibility performance during in-situ XRD analysis. In the long-term testing, R-LNMO outperformed C-LNMO in both average discharge capacity (123.17mAh g-1vs. 119.67mAh g-1) and capacity retention (94.66 % vs. 89.66 %) after 500 cycles at 1C/1C.Thus, our test results indicated that this recycled Li2CO3 showed the highly promising potential for reuse in various high-energy-density cathode materials preparation for LIBs re-applications.

Tailoring hyaluronic acid hydrogels: Impact of cross-linker length and density on skin rejuvenation as injectable dermal fillers and their potential effects on the MAPK signaling pathway suppression

Hyaluronic acid (HA) hydrogels, obtained through cross-linking, provide a stable 3D environment that is important for controlled delivery and tissue engineering applications. Cross-linking density has a significant impact on the physicochemical properties of hydrogels, including their shape stability, mechanical stiffness and macromolecular diffusivity. However, often cross-linking chemistries require photoinitiator and catalyst that may be toxic and cause unwanted tissue response. Here, we prepared a series of HA hydrogel with varying cross-linker length and cross-linking density, which can be obtained by altering the feed ratio of three different cross-linkers from small molecules to macromolecules (e.g., 1,4-butanediol diglycidyl ether (BDDE), ferulic acid (FA), pluronic (PLU)), to ameliorate skin wrinkles in mice models. HA cross-linked with FA and PLU exhibited enzyme and temperature-dependent sol-to-gel phase transition, respectively, and the gels possess good injectability. In vitro test confirmed that HA hydrogels co-cultured with RAW 264.7 and HDF cells showed good biocompatibility. In particular, HA cross-linked with PLU stimulated the growth of HDF cells and HaCaT cells. HA cross-linked with PLU suppressed the expression levels of proteins involved in collagen degradation including mitogen-activated protein kinases (ERK, JNK, p38) and matrix metalloproteases (MMP-1, MMP-3, and MMP-9) resulting in increased deposition of Collagen I. The free-flowing sols of HA hydrogel precursors are subcutaneously injected into the back of BALB/c mice and form stable gels at the dermis layer and found to be non-toxic. More importantly, HA hydrogel cross-linked with PLU showed an enhanced anti-wrinkling effect in the wrinkled mice model. Thus, properties of HA hydrogels such as injectability, biocompatibility, and good anti-wrinkling effect altered through varying cross-linking density must be considered in the context of soft tissue engineering applications.

Early inoculation and bacterial community assembly in plants: A review

The relationship between plants and early colonizing microbes is crucial for regulating agricultural ecosystems. Recent evidence strongly suggests that by introducing beneficial microbes during the seed or seedling stages, the diversity and assembly structure of the plant-related microbial community during later plant development can be altered, recruiting beneficial bacteria to enhance plant protection. However, the mechanisms of community assembly and their effects on plant growth are still not fully understood. To deepen our understanding of the importance of early inoculation for improving plant performance, this review comprehensively summarizes recent research advancements on the effects of early introduction on plant growth and adaptability. The mechanisms and ecological significance of early inoculation in the assembly of plant-related bacterial communities are discussed, with particular emphasis on the importance of seed endophytes, plant growth-promoting rhizobacteria (PGPR), and synthetic microbial consortia as microbial inoculants in enhancing plant health and productivity. Additionally, this review proposes a new strategy: sequential inoculation during the seed and seedling stages, aiming to maximize the effects of microbes.

Formamide-assisted synthesis of phosphate-intercalated Ni(OH)2/NiOOH electrode for boosting oxygen evolution reaction

Electrochemical water splitting (EWS) represents a promising method for green hydrogen production. However, the commercial viability of this approach is significantly hindered by the sluggish kinetics of the oxygen evolution reaction (OER). Layered Ni(OH)2/NiOOH serves as a low-cost and effective OER electrocatalyst, yet the activity and stability do not meet the requirements for commercial EWS, particularly in terms of operational stability under high current densities. Herein, we report a phosphate-intercalated (Pi) Ni(OH)2/NiOOH synthesized with the assistance of formamide (FA), termed NiOH-Pi-FA, which demonstrates significantly-enhanced OER performance. Systematic investigations reveal that FA facilitates phosphate intercalation, which improves OER via lattice oxygen oxidation, interlayer proton transport, electrode conductivity, electrode surface wetting and O2 bubbles release. More importantly, FA alters the catalyst's morphology, creating a porous structure and reducing catalyst particle size, which decreases the interlayer proton transport distance. FA also increases the surface roughness, promoting the release of O2 bubbles. Consequently, the OER performance of NiOH-Pi-FA is much better than that of Ni(OH)2/NiOOH prepared without FA (NiOH-Pi). It achieves overpotentials of 106 and 223 mV at current densities of 10 and 100 mA cm-2, respectively, and maintains exceptional stability at 350-330 mA cm-2 for over 400 h. Overall, the OER performance of NiOH-Pi-FA surpasses that of RuO2 and other Ni-based hydroxide electrocatalysts, offering valuable insights for designing efficient and stable OER catalysts.

Switching alkaline hydrogen oxidation reaction pathway via microenvironment modulation of Ru catalysts

Ruthenium (Ru) has emerged as a promising catalyst for alkaline hydrogen oxidation reaction (HOR). Nevertheless, its catalytic performance still remains substantially inferior to the requirements of practical applications. Strategic modulation of the Ru micro-environment offers significant potential for optimizing its intrinsic catalytic activity. In this study, by elaborately designing a micro-environment of asymmetrically coordinated cobalt single-atom (Co-N3O-C) structures for Ru, the obtained Ru/Co-N3O-C achieves an exceptional HOR activity of 0.98 mA μg-1Ru, which is 4.5-folds higher than Pt/C and 3.4-folds higher than Ru/Co-N4-C. Combined experimental and theoretical investigations uncover that the outstanding HOR activity originates from three positive influences brought by the precisely engineered asymmetric coordination of Co sites, as compared to the symmetric Co-N4-C environment, i.e., (i) through the electronic interaction between Ru and Co-N3O-C, the excessively high hydrogen binding energy (HBE) at Ru sites is suppressed, (ii) by lowering the d-band center of Co, the strong hydroxide binding energy (OHBE) on Co sites is alleviated and (iii) the hydrogen bonding network within the electronic double layer is more connective, facilitating the OH- transfer to react with Had, thus switching the HOR pathway from the OHBE mechanism to the apparent HBE mechanism. This work accentuates the critical role of microenvironment modulation in regulating the HOR pathway and provides a novel strategy for devising superior-performance HOR catalysts.

Organelle-oriented nanomedicines in tumor therapy: Targeting, escaping, or collaborating?

Precise tumor therapy is essential for improving treatment specificity, enhancing efficacy, and minimizing side effects. Targeting organelles is a key strategy for achieving this goal and is a frontier research area attracting a considerable amount of attention. The concept of organelle targeting has a significant effect on the structural design of the nanodrugs employed. Most notably, the intricate interactions among different organelles in a tumor cell essentially create a unified system. Unfortunately, this aspect might have been somewhat overlooked when existing organelle-targeting nanodrugs were designed. In this review, we underscore the synergistic relationship among the various organelles and advocate for a holistic view of organelle-targeting design. Through the integration of biology and material science, recent advancements in organelle targeting, escaping, and collaborating are consolidated to offer fresh perspectives for the development of antitumor nanomedicines.

Enrichment-catalytic synergistically enhanced electrochemiluminescence sensors based on IRMOF-3/CdTe for ultrasensitive detection of organophosphorus pesticides

To prevent organophosphorus pesticide (OPs) residues from threatening ecological environment safety and human health, the development of rapid and accurate monitoring methods is crucial. Herein, a newly quantum dot-functionalized metal-organic framework composite (IRMOF-3/CdTe) was synthesized, which achieved super strong cathodic electrochemiluminescence (ECL) emission in aqueous media. Among them, as a co-reaction accelerator, IRMOF-3 could efficiently enrich K2S2O8 and catalyze its generation of sulfate radical (SO4•-), while protecting metastable intermediates from environmental quenching, synergistically improving the ECL signal intensity. Moreover, by optimizing the synthesis ratio of IRMOF-3/CdTe and combining ECL intensity and electrochemical impedance spectroscopy (EIS) analysis, it was revealed for the first time that IRMOF-3 exerts a dual-edged effect on the ECL performance of CdTe. Based on the efficient ECL performance of IRMOF-3/CdTe and the inhibitory effect of OPs on acetylcholinesterase (AChE) activity, a highly sensitive ECL enzyme biosensor was constructed to detect profenofos (Pff). The fabricated biosensor exhibited a wide detection range (134 fM-1.34 mM) and a low detection limit (44.7 fM), and was successfully applied to the detection of Pff residues in actual samples (vegetables, milk and Yangtze River water). This study provided a new idea for the design of efficient ECL enzyme biosensors, which was of great significance for ensuring ecological and food safety.

Mobility and bio-accessibility of available phosphorus in sewage sludge: Influencing mechanism of hydrothermal pretreatment and incineration

Accurate assessment and enhancement of phosphorus (P) availability are critical for land application of sewage sludge and its thermal-treated products. By simulating different functioning pathways of P in soil, a novel multivariable scheme was developed to evaluate P availability from the perspective of mobility and bio-accessibility, then was applied to investigate the effects of hydrothermal pretreatment (HT), carbonaceous skeleton-assisted HT (CSkel-HT), and incineration on this topic. Sludge contained predominantly slow-release and microbial-available P (>50.0 % of total P). HT and incineration reduced available P through filtrate discharge, organic-P decomposition, and Fe/Al-P volatilization. Surprisingly, CSkel-HT addition promoted soluble Ca/MgHPO4 and thermal-stable Fe/AlPO4 formation under acidic conditions, which not only retained the slow-release and microbial-available P in hydrochar and ash, but also increased the rapid-available and plant-available P contents by 25.0 % and 300.0 %. Our scheme provided more informative insights than traditional single-index methods, and revealed the enhancing mechanism of CSkel-HT on P availability.

All-regional highly efficient moisture capturing and sunlight driven steam generation

Utilizing solar energy to extract and purify potable water from atmospheric humidity offers a viable approach to combat water scarcity in diverse geographical areas. However, current technologies face challenges related to low efficiency due to the low intrinsic permeability and weak hydrophilicity of H2O, followed by ineffectiveness in diverse climatic conditions and long-lasting implementation. Herein, we develop a highly hygroscopic photothermal hydrogels consisting of chitosan polypyrrole (CP) copolymer matrix and zinc ions (Zn2+). The chelation of Zn2+ with CP avoids ionic leakage and endows the hierarchically porous hydrogel with strong hydration and moisture-absorbing properties. These hydrogels achieve an effective moisture capturing of up to 6.53 g g-1 in a wide humidity range of 30% to 90%, which are the reminiscence of environment including desert and lakes. Furthermore, the grafting of photothermal polypyrrole to chitosan allowed the sunlight-driven steam generation with 87% efficiency of solar energy without additional power input. The recyclable moisture adsorption and desorption procedures maintain without observable deduction in efficiency over 2 weeks. A potable device containing our sunlight-driven antibacterial hydrogels displays the production of 1.3 kg m-2 drinkable water per day, sufficient to meet the needs of a household. Its potential for application across diverse climatic conditions could refine water harvesting practices and guide future research on system optimization and scalability.

Exploring biotechnology for plastic recycling, degradation and upcycling for a sustainable future

The persistent demand for plastic commodities, inadequate recycling infrastructure, and pervasive environmental contamination due to plastic waste present a formidable global challenge. Recycling, degradation and upcycling are the three most important ways to solve the problem of plastic pollution. Sequential enzymatic and microbial degradation of mechanically and chemically pre-treated plastic waste can be orchestrated, followed by microbial conversion into value-added chemicals and polymers through mixed culture systems. Furthermore, plastics-degrading enzymes can be optimized through protein engineering to enhance their specific binding capacities, stability, and catalytic efficiency across a broad spectrum of polymer substrates under challenging high salinity and temperature conditions. Also, the production and formulation of enzyme mixtures can be fine-tuned to suit specific waste compositions, facilitating their effective deployment both in vitro, in vivo and in combination with chemical technologies. Here, we emphasized the comprehensive strategy leveraging microbial processes to transform mixed plastics of fossil-derived polymers such as PP, PE, PU, PET, and PS, most notably polyesters, in conjunction with potential biodegradable alternatives such as PLA and PHA. Any residual material resistant to enzymatic degradation can be reintroduced into the process loop following appropriate physicochemical treatment.

Advanced nanoparticle engineering for precision therapeutics of brain diseases

Despite the increasing global prevalence of neurological disorders, the development of nanoparticle (NP) technologies for brain-targeted therapies confronts considerable challenges. One of the key obstacles in treating brain diseases is the blood-brain barrier (BBB), which restricts the penetration of NP-based therapies into the brain. To address this issue, NPs can be installed with specific ligands or bioengineered to boost their precision and efficacy in targeting brain-diseased cells by navigating across the BBB, ultimately improving patient treatment outcomes. At the outset of this review, we highlighted the critical role of ligand-functionalized or bioengineered NPs in treating brain diseases from a clinical perspective. We then identified the key obstacles and challenges NPs encounter during brain delivery, including immune clearance, capture by the reticuloendothelial system (RES), the BBB, and the complex post-BBB microenvironment. Following this, we overviewed the recent progress in NPs engineering, focusing on ligand-functionalization or bionic designs to enable active BBB transcytosis and targeted delivery to brain-diseased cells. Lastly, we summarized the critical challenges hindering clinical translation, including scalability issues and off-target effects, while outlining future opportunities for designing cutting-edge brain delivery technologies.

Unravelling AMR dynamics in the rumenofaecobiome: Insights, challenges and implications for One Health

Antimicrobial resistance (AMR) is a critical global threat to human, animal and environmental health, exacerbated by horizontal gene transfer (HGT) via mobile genetic elements. This poses significant challenges that have a negative impact on the sustainability of the One Health approach, hindering its long-term viability and effectiveness in addressing the interconnectedness of global health. Recent studies on livestock animals, specifically ruminants, indicate that culturable ruminal bacteria harbour AMR genes with the potential for HGT. However, these studies have focused predominantly on using the faecobiome as a proxy to the rumen microbiome or using easily isolated and culturable bacteria, overlooking the unculturable population. These unculturable microbial groups could have a profound influence on the rumen resistome and AMR dynamics within livestock ecosystems, potentially holding critical insights for advanced understanding of AMR in One Health. In order to address this gap, this review of current research on the burden of AMR in livestock was undertaken, and it is proposed that combined study of the rumen microbiome and faecobiome, termed the 'rumenofaecobiome', should be performed to enhance understanding of the risks of AMR in ruminant livestock. This review discusses the complexities of the rumen microbiome and the risks of AMR transmission in this microbiome in a One Health context. AMR transmission dynamics and methodologies for assessing the risks of AMR in livestock are summarized, and future considerations for researching the impact of AMR in the rumen microbiome and the implications within the One Health framework are discussed.

Investigation of self-assembly mechanism of gluten protein amyloid fibrils and molecular characterization of structure units

The mechanism of peptides self-assembly into gluten amyloid fibrils was explored through bond-breaking experiments and molecular dynamics (MD) simulations, verified through fibrillation experiments using synthetic peptides. The disruption of hydrogen bonds reduced thioflavin T fluorescence intensity and average particle size of gluten amyloid fibrils by 24 % and 81 %, respectively, causing a breakdown of internal structure. Disruption of electrostatic and hydrophobic forces induced further aggregation of fibrils. MD simulation revealed that peptides transitioned from a dispersed state to aggregation, followed by changes in secondary structure, culminating in the formation of stacked β-sheets structure units. Hydrogen bonding emerged as the primary driver of self-assembly with contributions from hydrophobic and electrostatic interactions. The synthetic single or hybrid peptide systems selected by MD formed ribbon- or fiber-like amyloid fibrils with inter-strand distance of 4.7 Å and respective inter-sheet distances of 10.2 Å and 10.8 Å, suggesting that the structure and morphology of eventual amyloid fibrils were affected by the peptide sequence and cross β-sheet structure units.

Alternating electrodeposition fabrication of graphene-buffered nickel-cobalt layered double hydroxide supercapacitor electrodes with superior rate capability

Combining pseudocapacitive materials with carbon materials, such as graphene, is a promising strategy to enhance their performance. In this study, we present a novel and feasible approach involving the alternating electrodeposition of reduced graphene oxide (rGO) and nickel-cobalt layered double hydroxide (NiCo-LDH) onto carbon cloth (CC) current collectors to fabricate binder-free supercapacitor electrodes with a layered LDH/rGO/LDH/rGO/CC architecture. The rGO layers are not only coated on CC substrate to regulate the electrodeposition of LDH nanosheets, but also interposed between the LDH layers to further enhance conductivity and provide buffering effects. The as-prepared electrode achieves a high specific capacitance of 2400 F g-1 at a current density of 1 A g-1, with an outstanding rate capacity retaining 83.1 % of the capacitance at 60 A g-1 and even a retention of 72.5 % at 100 A g-1. Furthermore, the asymmetric supercapacitor configured using the composite electrode and an activated-carbon electrode delivers an energy density of 38.7 Wh kg-1 at a power density of 825 W kg-1, accompanied by excellent cyclic stability with a capacitance retention of 74.4 % after undergoing 10,000 charge/discharge cycles. This work proposes an innovative methodology for fabricating LDH-based functional composites in supercapacitors and other related fields.

Transformative biomedical devices to overcome biomatrix effects

The emergence of high-performance biomedical devices and sensing technologies highlights the technological advancements in the field. Recently during COVID-19 pandemic, biosensors played an important role in medical diagnostics and disease monitoring. In the past few decades, biosensors have made impressive advances in terms of sensing capability, methodology, and applications, and modern biosensors show higher performance and functionality compared to traditional biosensing platforms. Currently, various biomedical devices are already in the market or on the verge of commercialization, such as disposable paper-based devices, lab-on-a-chip devices, wearable sensors, and artificial intelligence-assisted systems, all contributing to the evolution of digital health. Despite the promising features of detection methods for developing practical biosensors, there are substantial barriers to the commercialization of biomedical devices. An important challenge is the matrix effect in the detection of clinical samples. Although achieving low limit of detection values under controlled laboratory conditions is feasible, maintaining performance in real clinical samples is difficult. Matrix molecules present in these samples can interact with analytes, potentially affecting sensitivity, specificity, and sensor response. Approaches to reduce nonspecific adsorption and cross-reactivity are imperative for improving sensor performance. The detection of diagnostic biomarkers in complex biological matrices often requires laborious sample preparation, which may affect accuracy and precision. In this review, we highlight the recent efforts to detect analytes in real samples, both invasively and noninvasively, and underline technological advancements that mitigate the biomatrix effects. We also discuss commercially available biosensors and technologies promising commercial success, highlighting their potential effect on healthcare and diagnostics.

A site-specific fluorogenic probe for protein disulfide isomerase A1

BACKGROUND

Protein disulfide isomerase A1 (PDIA1) is essential for catalyzing disulfide bond isomerization, ensuring proper protein folding, and maintaining cellular homeostasis. Dysregulation of PDIA1 function is implicated in various diseases, emphasizing the need for tools to study its activity dynamically and specifically. Despite this need, current methods lack the sensitivity and robustness required for reliable detection of PDIA1 activity.(57) RESULTS: We synthesized a series of vinyl sulfone-based fluorescent probes capable of covalently binding to thiol groups, triggering fluorescence activation. Among these, the probe LS exhibited outstanding performance, achieving a ∼18-fold fluorescence intensity increase upon binding to PDIA1. LS showed high specificity for PDIA1 by selectively targeting the cysteine residue at position 397 in its active site. The probe demonstrated rapid fluorescence activation with significant intensity enhancement within a short time. Furthermore, LS featured consistent excitation and emission wavelengths, making it ideal for fluorescence-based detection. (84) SIGNIFICANCE: The strong targeting ability, rapid response, and stability of LS provide a powerful platform for real-time, dynamic monitoring of PDIA1 activity. This probe holds significant promise for exploring PDIA1's roles in physiological and pathological processes and advancing research in PDIA1-associated diseases using vinyl sulfone-based fluorescent probes.(46).

Quercetin-derived carbon dots promote proliferation and migration of Schwann cells and enhance neurite outgrowth

Quercetin, a flavonoid known for its antioxidant properties, has recently garnered attention as a potential neuroprotective agent for treatment of the injured nervous system. The repair of peripheral nerve injuries hinges on the proliferation and migration of Schwann cells, which play a crucial role in supporting axonal growth and myelination. In this study we synthesized Quercetin-derived carbon dots (QCDs) and investigated their effects on cultured Schwann cells and the NG108-15 cell line. QCDs was obtained by solvothermal synthesis and characterized via UV-vis absorption spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction analysis. The particles demonstrated significant dose-dependent free radical scavenging activity in DPPH and ABTS radical scavenging assays, supported in vitro proliferation and migration of Schwann cells, expression of neurotrophic and angiogenic growth factors, and stimulated neurite outgrowth from NG108-15 cells. Thus, QCDs could serve as a potential novel treatment strategy to promote regeneration in the injured peripheral nervous system.

Selenium nanoparticles as catalysts for nitric oxide generation

The critical role of nitric oxide (NO), a potent signalling molecule, in various physiological processes has driven the development of NO delivery strategies for numerous therapeutic applications. However, NO's short half-life poses a significant challenge for its effective delivery. Glutathione peroxidase, a selenium-containing antioxidant enzyme, can catalyse the decomposition of S-nitrosothiols (endogenous NO prodrugs) to produce NO in situ. Inspired by this, we explored selenium nanoparticles (SeNPs) for their enzyme-mimicking NO-generating activity. Stabilised with polyvinyl alcohol (PVA) or chitosan (CTS), SeNPs demonstrated tuneable NO generation when exposed to varying concentrations of NO prodrug, nanoparticles, and glutathione (GSH). In the presence of GSH, a naturally occurring antioxidant in the human body, 0.1 µg mL-1 of SeNPs could catalytically generate 7.5 µM of NO under physiological conditions within 30 min. We investigated the effects of nanoparticle crystallinity and NO prodrug type on NO generation, as well as the stability and sustained NO generation of the catalytic nanoparticles. PVA-stabilised SeNPs were non-toxic to NIH 3T3 cells and effectively dispersed Pseudomonas aeruginosa biofilms upon NO generation. This study broadens the repertoire of nanomaterials for NO generation and highlights SeNPs as a non-toxic alternative for therapeutic NO delivery.

Optimizing nonlinear optical and photovoltaic performance in butterfly-shaped carbazole vs. borole derivatives: An implicit and explicit solvents-driven approach

Nonlinear optical (NLO) materials play a crucial role in various hi-tech optoelectronic applications, driving the quest for novel molecular frameworks with superior properties. In this context, this study systematically explores derivatives of phenanthrene-carbazole and phenyleno-borole, aiming to finely tune their NLO properties by incorporating multiple push-pull groups at their molecular periphery. The integration of these push-pull groups with the central core significantly enhances intramolecular charge transfer (ICT) within the molecular structures, leading to improved optical and NLO properties. Our findings highlight compound 3-PB as a standout among the designated compounds, exhibiting exceptional linear optical properties with the maximum linear isotropic (αiso) value of 95.77 × 10-24 esu and a maximum anisotropic (αaniso) of 106.6 × 10-24 esu. Notably, it also shows an impressive average static third-order NLO polarizability <γ> amplitude of 574.1 × 10-36 esu. A comparative study reveals that the <γ> amplitude of 3-PB is ∼78 times greater than p-NA (7.29 × 10-36 esu) at the M06/6-311G∗∗ level of theory. TD-DFT computations further attribute the remarkable NLO response of 3-PB to its lower transition energy, setting it apart from the other designated molecular systems. Additionally, TD-DFT calculations explored structure-NLO property relations through FMOs, DOS, and MEP maps. A detailed comparison of NLO polarizabilities and electronic properties highlights the significance of carbazole and borole-based systems in achieving strong NLO responses. Notably, compound 3-PB exhibits enhanced NLO properties due to the presence of polyaromatic rings and a boron atom serving as an acceptor, along with dimethylamine (donor group) substitutions at the periphery of the molecule. Beyond exceptional NLO performance, our entitled systems also demonstrate favorable photovoltaic potential. Specifically, compound 3-PB exhibits the highest LHE value of 0.999. Additionally, open circuit voltage values range from 1.55 to 3.02 eV, while lower ΔGreg values suggest that these compounds are promising candidates for sensitizing DSSC performance.

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.

Multiplexed and highly sensitive FRET aptasensor for simultaneous assay of multiple antibiotics via DNAzyme and catalytic strand displacement amplification cascades

BACKGROUND

The emergence of antibiotic-resistant microorganisms poses significant risks to public health. Therefore, the development of technologies capable of detecting antibiotics with high sensitivity and selectivity is essential for monitoring and controlling the spread of antibiotic resistance. Yet, current major available antibody-based antibiotic detection methods often face limitations in sensitivity, complexity, and cost, and commonly one target antibiotic can be detected in one assay.

RESULTS

On the basis of a three-way DNA junction (3-WJ) signal construct, we describe a multiplexed fluorescence resonance energy transfer (FRET) aptasensor strategy for highly sensitive simultaneous detection of sarafloxacin (SAR) and enrofloxacin (ENR) through cyclic DNAzyme and catalytic strand displacement reaction (CSDR) signal amplification cascades. Target antibiotics are recognized separately by the aptamers in DNAzyme/apamer duplexes to release active DNAzyme sequences, which cleave the dumbbell substrate hairpins to free ssDNAs to trigger subsequent CSDR between the assistance hairpins and the 3-WJ constructs for formation of many fluorophores 5-carboxyfluorescein (FAM)- and 2',7'-dimethoxy-4', 5'-dichloro-6-carboxyfluorescein (JOE)/6-carboxy-X-rhodamine (ROX)-labeled DNA duplexes. This leads to the pulling of FAM dye donor in proximity to the ROX and JOE dye acceptors, facilitating the yield of considerably amplified FRET signals at 555 nm and 605 nm for the SAR and ENR assays, respectively, with detection limits of 1.95 pM (0.76 ng/L) and 5.01 pM (1.8 ng/L) within 2.5 h. Additionally, this sensing method can selectively discriminate SAR and ENR against non-target antibiotics and has been validated for the simultaneous detection of SAR and ENR in milk samples.

SIGNIFICANCE

Featured with the advantages of convenient and significant signal amplification capability as well as single excitation for multiplexed detection, the successful demonstration of our method for sensitive and simultaneous detection of two antibiotics therefore shows its promising potential for constructing different multiplexed aptasensors for detecting various low levels of biomolecules.

Cyclodextrin-based liquid crystals: A novel approach to promote the formation of thermotropic cubic mesophases and their potential applications as electrolytes

We report the synthesis and mesomorphic studies of a family of amphiphilic β-cyclodextrin derivatives that are polyesterified at the secondary face with either 14 lauroyl or 14 stearoyl chains (apolar), and 7 tri- or tetra-ethylene glycols (polar) at the primary face. The end of each tri- and tetra-ethylene glycol chain is further modified with different terminal functionalities in term of their dipole moment (O-methyl vs O-acetyl vs O-2-cyanoethyl). This has generated several subgroups of amphiphilic β-cyclodextrin derivatives with a systematic change of their relative volumes of the hydrophobic and hydrophilic regions. Our studies showed that all these derivatives self-assemble into thermotropic liquid crystals, with the majority forming hexagonal column mesophases while three compounds form a bicontinuous cubic phase. We rationalized the mesomorphic behaviour of these compounds in term of the relative total van der Waals fractional volumes occupied by the hydrophilic and hydrophobic chains. Upon added with LiTFSI, the formed bicontinuous cubic phase (as a pure compound) was found to transition to form the more stable smectic A mesophase (composite), and both solid NMR studies and impedance spectroscopy revealed that these novel amphiphilic β-cyclodextrin-based liquid crystalline materials have the potential to be used as efficient electrolytes for lithium conduction.

Nanocellulose composites with enhanced mechanical and flame-retardant properties based on grafting of inorganic organic/multilayer core-shell matter - MSNs-TMSB/DA/TOCNF

Flame retardant materials are essential for safety, yet their development is often hindered by trade-offs between efficiency, aging resistance, and mechanical properties. Traditional organic flame retardants are inefficient and degrade over time, while inorganic alternatives, despite their effectiveness, are difficult to integrate into composites. Here we showed the synthesis of a novel inorganic silica-based flame retardant, PDA@MSNs-TMSB, which chemically modified nanocellulose fibrils, enhancing flame retardancy, aging resistance, and toughness without compromising integrity. The results showed that, compared to pure TOCNF, the modified nanocellulose materials (TOCNF-PDA@MSNs-TMSB) exhibited a higher limiting oxygen index (46.5 %), reaching the UL-94 V-0 level (GB) rating with self-extinguishing behavior and no flame propagation. In contrast, pure TOCNF had a limiting oxygen index of only 22 % and burned rapidly upon ignition which did not achieve the UL-94 V-0 level rating. The toughness of the modified TOCNF-PDA@MSNs-TMSB was superior to that of pure TOCNF, representing a 37.5 % increase. Combining powerful tenacity, high flame retardancy, and better aging resistance, the flame retardant nanocellulose material from renewable resource shows great potential for flame retardant applications and emits no toxic byproducts post-combustion.

Self-replicating nanomaterials as a new generation of smart nanostructures

Self-replication is the process by which a system or entity autonomously reproduces or generates copies of itself, transmitting hereditary information through its molecular structure. Self-replication can be attractive for various researchers, ranging from biologists focused on uncovering the origin of life, to synthetic chemists and nanotechnologists studying synthetic machines and nanorobots. The capability of a single structure to act as a template to produce multiple copies of itself could allow the bottom-up engineering of progressively complex reaction networks and nanoarchitectures from simple building blocks. Herein, we review nucleic acid-based and amino acid-based self-replicating systems and completely synthetic artificial systems and specially focused on specific aspects of self-replicating nanomaterials. We describe their mechanisms of action and provide a full discussion of the principal requirements for achieving nanostructures capable of self-replication.

Anaerobic probiotics-in situ Se nanoradiosensitizers selectively anchor to tumor with immuno-regulations for robust cancer radio-immunotherapy

Developing translational nanoradiosensitizers with multiple activities in sensitizing tumor cells and re-shaping tumor immunosuppressive microenvironments are urgently desired for addressing the poor therapeutic efficacy of radiotherapy in clinic. Inspired by the anaerobic and immunoagonist properties of the probiotic (bifidobacterium longum, BL), herein, a biomimetic Selenium nanoradiosensitizer in situ-formed on the surface of the probiotic (BL@SeNPs) is developed in a facile method to potentiate radiotherapy. BL@SeNPs selectively target to hypoxia regions of tumors and then anchor on the surface of tumor cells to inhibit its proliferation. Meanwhile, it also significantly promotes ROS generations to damage DNA and induces cell cycle arrest for enhancing the therapeutic efficacy of radiotherapy, which will induce immunogenic cell death to initiate antitumor immunities. In addition, BL@SeNPs nanoradiosensitizers can serve as immunoagonist to activate immune cells like dendritic cells (DCs) to further magnify the quality of the induced immune responses. More importantly, BL@SeNPs combining radiotherapy effectively reduce immunosuppressor cells (e.g. TAM, MDSC, TAN) infiltrating within tumors for shaping tumor microenvironments to effectively combat tumor progressions. This study provides a safe, effective and translational nanoradiosensitizer and its combination radiotherapy for clinical cancer treatment and shed lights for developing next generation of nanoradiosensitizers.

Advances in locally administered nucleic acid therapeutics

Nucleic acid drugs represent the latest generation of precision therapeutics, holding significant promise for the treatment of a wide range of intractable diseases. Delivery technology is crucial for the clinical application of nucleic acid drugs. However, extrahepatic delivery of nucleic acid drugs remains a significant challenge. Systemic administration often fails to achieve sufficient drug enrichment in target tissues. Localized administration has emerged as the predominant approach to facilitate extrahepatic delivery. While localized administration can significantly enhance drug accumulation at the injection sites, nucleic acid drugs still face biological barriers in reaching the target lesions. This review focuses on non-viral nucleic acid drug delivery techniques utilized in local administration for the treatment of extrahepatic diseases. First, the classification of nucleic acid drugs is described. Second, the current major non-viral delivery technologies for nucleic acid drugs are discussed. Third, the bio-barriers, administration approaches, and recent research advances in the local delivery of nucleic acid drugs for treating lung, brain, eye, skin, joint, and heart-related diseases are highlighted. Finally, the challenges associated with the localized therapeutic application of nucleic acid drugs are addressed.

Tumor microenvironment-activated and near-infrared light-driven free radicals amplifier for tetra-modal cancer imaging and synergistic treatment

The tumor microenvironment (TME) exhibits a specific feature of hypoxia, which poses significant challenges for oxygen (O2)-dependent treatments. In this study, we developed an intelligent nanoplatform (PEGylated AIPH@MSN/CDs-MnO2, denoted as A@M/C-Mn) by integrating a photosensitizer of red carbon dots (CDs) with a thermolabile initiator-loaded mesoporous silica nanoparticle (AIPH@MSN, denoted as A@M), and then growing manganese dioxide nanosheets (MnO2 NS) in situ and PEGylating the structure to achieve TME-responsive synergistic diagnosis and phototherapy against hypoxic tumors. The outer-layer MnO2 NS has the capability to decompose endogenous hydrogen peroxide (H2O2) in the acidic TME, thereby producing O2 to alleviate hypoxia while releasing Mn2+. This process restores the fluorescence (FL) and photodynamic therapy (PDT) properties of the CDs, enhancing singlet oxygen (1O2) generation upon near-infrared (NIR) laser irradiation. Concomitantly, the exposed CDs induce hyperthermia for photothermal therapy (PTT) and promote the decomposition of AIPH to form cytotoxic alkyl radicals (R) for O2-independent PDT. Importantly, the entire treatment process can be monitored through ultrasound (US)/magnetic resonance (MR)/photoacoustic (PA)/FL imaging, owing to O2 production, Mn2+ release, and CDs activation, respectively. Both in vitro and in vivo results provide evidence that A@M/C-Mn represents a promising theranostic nanoagent for hypoxic tumors.

Nitrogen imported in nickel clusters promotes carbon dioxide electrochemical reduction to carbon monoxide

The Ni-N coordination structure has been shown to be conducive to the electrochemical CO2 reduction reaction (CO2RR) to CO, and this process has been extensively validated. However, the impact of Ni-N coordination structures within Ni-based clusters on CO2RR has received relatively limited research attention to date. In this study, catalysts containing Ni single atoms and Nin clusters (Ni-N/Nin) were synthesised, and subsequently, Nin clusters were transformed into NinNx clusters (Ni-N/NinNx) through secondary nitridation. The experimental results, as illustrated by X-ray photoelectron spectra and X-ray absorption fine structure spectra, demonstrate that the Ni-N bond in Ni-N/NinNx increased and Ni-N-Ni bonds within atomic clusters were generated, thereby confirming the transformation from Nin clusters to NinNx clusters. Density functional theory calculations show that the NinNx clusters have a lower energy barrier for the *CO2- + H+ → *COOH step compared to Nin clusters, and promote the entire reaction. Furthermore, in-situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and density functional theory (DFT) calculations collectively indicate that abundant Ni-N coordination structures in clusters effectively reduce the energy barrier of CO2 + e- → *CO2- and facilitate the activation of CO2 to *CO2- across a broader potential window. Ni-N/NinNx demonstrates high Faraday efficiency of CO (FECOmax = 98.6 % at -0.4 V vs. RHE), a wider potential window (-0.3 to -0.8 V vs. RHE, FECO > 90 %) and high CO partial current density (jCO > 100 mA cm-2). In comparison with Ni-N/Nin, the maximum CO partial current density of Ni-N/NinNx is enhanced by approximately 4.6 times. These findings offer valuable insights into the structure-activity relationship of Ni-based cluster catalysts and facilitate the development of more advanced atomically cluster catalysts.

Transition metal doped pyrazine-graphyne for high-performance CO2 reduction reaction to C1 products

The pressing necessity to mitigate climate change and transition to a sustainable energy economy underscores the importance of developing highly efficient and selective catalysts for electrocatalytic CO2 reduction (CO2RR). This study explores nitrogen-doped graphyne (N-GY) as a promising substrate for anchoring 3d and 4d transition metal atoms (TMs), facilitating the creation of high-performance electrocatalysts. Through comprehensive computational analysis based on density functional theory (DFT), we provide a detailed understanding of the mechanisms involved in CO2 capture by these catalysts. Our results reveal a "donation-backdonation" mechanism during CO2 adsorption, characterized by significant charge transfer and orbital overlap, which enhance CO2 adsorption and activation. We identify ten catalysts exhibiting exceptional activity and selectivity, with V-S2@N-GY standing out for its ultra-low limiting potential of -0.279 V, which is particularly beneficial for carbon monoxide generation. The mechanistic analysis further underscores the critical role of the *COOH intermediate adsorption strength in dictating CO2RR activity. This study provides valuable theoretical insights for the design and optimization of efficient CO2RR catalysts.

A telomerase-enhanced homogeneous cascade amplification strategy designed for highly sensitive electrochemical detection of microRNA

Highly sensitive and specific detection of microRNAs (miRNAs) is vital for cancer early diagnosis. In this work, we have proposed a telomerase-enhanced homogeneous cascade amplification strategy for high-performance electrochemical detection of miRNA-21 (miR-21). The target miRNA is first transcribed and amplified into massive single-stranded output DNA fragments through the endonucleases-assisted primary amplification element. Then, the output DNAs can activate the telomerase-promoted entropy-driven DNA catalytic (EDC) circuit, which can significantly improve the amplification efficiency and release a mass of linker DNAs, achieving the secondary amplification of miR-21. Finally, the G-quadruplex loaded with plenty of electroactive substances can be captured on the electrode via the linker DNAs for highly sensitive detection of miR-21. The fabricated electrochemical biosensor exhibits a broad linear range from 1 aM to 1 nM with the detection limit of 0.36 aM. The exceptional sensitivity and specificity endow this biosensor with the ability to discriminate miR-21 from the interference miRNAs and proteins. In addition, the biosensor has been utilized to analyze miR-21 expression levels in human serum and diverse cell lysates, demonstrating its practicability in real sample analysis. Therefore, our designed electrochemical biosensor will have huge potential in analysis of cancer-related miRNA and early cancer diagnosis.

Bulky substrates of isoleucine 2-epimerase: α-Neopentylglycine and NV-5138

Isoleucine 2-epimerase from Lactobacillus buchneri (LbIleE) catalyzes the pyridoxal 5'-phosphate-dependent, reversible, racemization or epimerization of nonpolar amino acids at the C-2 position. The integral role of the enzyme in the biosynthesis of branched-chain d-amino acids makes it a potential target for the development of antimicrobial agents. Probing the hydrophobic active-site pocket with a series of alkyl boronic acids, we show that the hydrophobic pocket accommodates the neopentyl group with enhanced binding affinity relative to the sec-butyl group. Subsequently, we show that LbIleE catalyzes the racemization of l- and d-α-neopentylglycine, exhibiting binding affinities for these substrates 6- and 24-fold greater than those for l-Ile and d-allo-Ile, but with catalytic efficiencies (kcat/Km) reduced 46- and 27-fold, respectively. NV-5138 is a ligand of the leucine-binding site of Sestrin2, which activates the mechanistic target of rapamycin complex1 (mTORC1) and is structurally similar to α-neopentylglycine. Our demonstration that LbIleE catalyzes the racemization of l-NV-5138 (kcat/Km = 2.2 ± 0.2 s-1 mM-1), along with the fact that L. buchneri can be present in the human gut microbiome, suggests that formation of d-NV-5138 could occur in humans when l-NV-5138 is used as a pharmacological intervention for depression.

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.

Ultra-small gold nanoparticle-coupled MOF-808 enabled sensitive detection of bacteria at neutral pH

Metal-organic framework (MOF)-based mimics are considered star materials to replace natural enzymes. However, their activity is generally limited to acidic conditions, which severely restricts their applications in biological systems where neutral pH is commonly required. Herein, a Zr(IV)-based MOF (MOF-808)/gold nanoparticle (AuNP) hybrid (called Hybrid-60) that shows superior peroxidase-like (POD-like) activity in both acidic and neutral media was prepared by in-situ growth of ultra-small AuNPs (UsAuNPs, ∼3.5 nm) on MOF-808. In comparison with the conventional AuNPs and MOF-808 nanozymes, Hybrid-60 demonstrated ∼8.04- and ∼6.74-time enhanced POD-like activities and superior high activity under neutral conditions, which broke the pH limitation. Furthermore, Hybrid-60 exhibited good tolerance to extreme pH value, concentrated salinity, and high-temperature environments. Taking Staphylococcus aureus (S. aureus) as a model analyte, we developed a simple immune sandwich assay using Hybrid-60 as colorimetric nanotags (ISAHC). A dual recognition strategy using anti-S. aureus antibody and concanavalin A-labeled Hybrid-60 was proposed to specifically capture and high-affinity label the target S. aureus. Then, leveraging the high POD-like activity of Hybrid-60, a simple and specific detection of S. aureus at nearly neutral pH was realized with a wide linear range (1 × 102-1 × 105 CFU/mL) and a low detection limit (32 CFU/mL). Moreover, the ISAHC method enabled one to detect the target S. aureus in human urine and serum with satisfactory recoveries from 93.8 % to 111.0 %, which indicates its clinical applicability. This study provides a new approach to develop neutral nanozymes and facilitate the point-of-care detection of bacteria.

Tailored microenvironment of functional DNA enables highly robust blood estradiol tests

Monitoring estradiol (E2) levels in the blood is crucial for obtaining reliable hormone levels necessary for assessing overall reproductive and cardiovascular health. While existing techniques like mass spectrometry and chemiluminescence immunoassays offer high sensitivity and selectivity, they are often complex, costly, and suffer from issues, such as cross-reactivity and limited biostability. Herein, we present a DNA-based method for E2 detection in blood, which mitigates the matrix effect using engineered DNA microenvironments. We demonstrate that incorporating heparin significantly enhances the binding between aptamers and E2 using fluorescence and electrochemical assays. Additionally, the presence of non-charged polymer on electrode surface reduces the apparent dissociation constant by over 70-fold, enabling us to design assays that overcome the dynamic range limitations of surface binding assays. Our method proves reliable for monitoring E2 levels in clinical samples, including those from women undergoing hormone replacement therapy, assisted reproductive technology, and throughout the menstrual cycle. Overall, our work presents a promising approach for E2 testing in blood and underscores the critical role of the DNA local environment in target recognition within biological settings.

Visual quantitative point-of-care immunoassay based on signal transduction amplification and hue-recognition analysis

Visual based immunoassay employs both human eye interpretation and machine-vision (smartphone imaging) quantification for equipment-independent diagnosis of biomarkers, fitting a variety of scenarios such as home-testing. Here we use hue-recognition strategy to create vivid and sensitive color changes against C-reactive protein (CRP) for accurate visual analysis. The red-to-green tonality gradient presentation was realized by ratiometric fluorescent probe using dual-emissive quantum dots (QDs) structure. The sandwich immuno-capturing process of antigen was integrated on ELISA plate, with the signal amplified and transduced by silver particle labels etching and interaction with the ratiometric QDs probe. The narrow-emissive QDs with selective response to released Ag+ ions produced high color fidelity and prominent hue variation towards analyte concentration. This portable immunoassay enabled eye-perception of 5 specific CRP concentration points (0, 5, 50, 200, 500 ng/mL) and 4 concentration intervals (0-5, 5-50, 50-200, 200-500 ng/mL) with reading accuracy of 97.5 % and 96.4 %, respectively, which is superior against traditional lightness-gradient based reading mode. With the aid of smartphone imaging and software color-analyzing, an elaborated quantification of CRP was achieved via color information. The broad CRP responsive range (0-500 ng/mL), low limit of detection (0.062 ng/mL) and high specificity against protein substrates allowed a robust point-of-care CRP clinical diagnosis application.

The amyloidogenic peptide stretch in human tau, tau306-311 is a promising injectable hydrogelator

A vast majority of peptide hydrogelators harbor a bulky, non-native aromatic moiety. Such foreign moieties raise safety concerns as far as biomedical applications of hydrogels are concerned. The hydrogel research, therefore, has branched to another dimension - to identify native or native-like short peptide stretches that could cause the gelation of biological fluids. Using well-defined criteria to identify native peptide stretches that could form a viscous solution in water but cause gelation of phosphate-buffered saline (PBS), we identified the hexapeptide stretch from human tau, viz. tau306-311, as a promising injectable hydrogelator. The peptide causes instant gelation of PBS and the cell culture media. Such hydrogels find applications as drug delivery vehicles, scaffolds for mammalian cell culture, wound-dressing material, etc.

The bidirectional matter transfer in adsorption-promoted photocatalytic ozonation system derived by triazine nanosheets-heptazine nanotubes homojunction composite biochar

Heterogeneous catalytic ozonation (HCO) process is an efficiency and eco-friendly solution to the growing challenge of water purification, yet is challenging by O3 utilization, pollutants selectivity, and matter transfer resistance. Herein, adsorption-promoted photocatalytic ozonation (HCO/POAP) system was constructed derived by triazine nanosheets-heptazine nanotubes homojunction carbon nitride composite Enteromorpha prolifera derived biochar (CNTh-St/EpC) to provide a targeted solution for the refractory organic pollutants treatment. In the HCO/POAP system, the adsorption sites predominantly reside on EpC, while the catalytic sites are primarily located on CN. The construction of efficient transport channels is facilitated by the induction of triazine structures from amorphous C, N compounds along the edges of heptazine. This leads to the independent yet closely interconnected process of inward transfer of pollutants and outward transfer of active species, confining reactions to a bidirectional transfer channel. This strategic confinement significantly amplifies the performance of HCO/POAP system. Specifically, the removal rates are 80 % for TC and 94 % for PNP in 30 min with almost entirely harmless or non-toxic degradation products, and mark a 56 % and 77 % enhancement over O3 system, respectively. Moreover, the HCO/POAP system demonstrates exceptional efficacy in treating dissolved organic matter, chemical oxygen demand (COD), and ultraviolet absorbance at 254 nm (UV254) in diverse actual wastewater. This study highlights the potential of HCO/POAP process in efficient water purification, and provides mechanistic insights into the bidirectional matter transfer during the contaminants remove.

Controlled synthesis of superhydrophilic flower-like hierarchical porous diboronate affinity materials for capturing biomarkers

BACKGROUND

Boronate affinity chromatography represents a powerful analytical technique for the selective separation and enrichment of biomolecules containing cis-diol moieties, including carbohydrates, glycoproteins, and other cis-dihydroxy compounds. While boronate affinity materials (BAMs) have shown promise in glycosylation-based separation and analysis, their practical application is hindered by non-biocompatible binding pH, low enrichment efficiency for low-abundance samples, non-specific adsorption, and limited loading capacity. To address these limitations, this work focuses on developing flower-like hierarchical porous diboronate affinity materials (FHP-DBAMs) with enhanced binding strength, selectivity, and capacity for cis-diol-containing biomolecules.

RESULTS

FHP-DBAM was synthesized via a facile sol-gel method, using tetrahydroxydiboron as a hydrophilic diboronic acid monomer. The electron-withdrawing nature and hydrophilicity of diboronate affinity mechanism enable FHP-DBAM to operate at lower pH values (pH ≥ 5), addressing the biocompatibility issue. DFT and experiment calculations confirm the enhanced cis-diol binding affinity of diboronate affinity mechanism compared with monoboronate affinity mechanism, resulting in a remarkably low dissociation constant (DFT Kd = 6.74 × 10-5 M, experiment Kd = 9.95 × 10-5 M) for FHP-DBAM. Furthermore, the unique flower-like hierarchical porous structure provides a high surface area and nanoconfinement effect, significantly boosting target molecule loading capacity and affinity reaction kinetics. Compared to traditional BAMs, FHP-DBAM exhibits over ten times higher loading capacity. As a proof-of-concept, FHP-DBAM successfully captures the biomarker GM1 in breast cancer cells MCF-7 with high efficiency.

SIGNIFICANCE AND NOVELTY

This work introduces diboronate affinity mechanism and flower-like hierarchical porous structure as new solution to overcome the limitations of conventional BAMs. FHP-DBAMs achieve lower binding pH, enhanced selectivity, and stronger binding stability through diboronate affinity mechanism. The unique flower-like porous structure maximizes surface area and active sites, addressing low enrichment efficiency and loading capacity. These advancements are critical for the efficient and biocompatible separation of cis-diol-containing biomolecules.