Stick, Slide, or Bounce: Charge Density Controls Nanoparticle Diffusion.

The diffusion and interaction dynamics of charged nanoparticles (NPs) within charged polymer networks are crucial for understanding various biological and biomedical applications. Using a combination of coarse-grained molecular dynamics simulations and experimental diffusion studies, we investigate the effects of the NP size, relative surface charge density (ζ), and concentration on the NP permeation length and time. We propose a scaling law for the relative diffusion of NPs with respect to concentration and ζ, highlighting how these factors influence the NP movement within the network. The analyses reveal that concentration and ζ significantly affect NP permeation length and time, with ζ being critical, as critical as concentration. This finding is corroborated by controlled release experiments. Further, we categorize NP dynamics into sticking, sliding, and bouncing regimes, demonstrating how variations in ζ, concentration, and NP size control these behaviors. Through normalized attachment time (NAT) analyses, we elucidate the roles of electrostatic interactions, steric hindrance, and hydrodynamic forces in governing NP dynamics. These insights provide guidance for optimizing NP design in targeted drug delivery and advanced material applications, enhancing our understanding of NP behavior in complex environments.

Multifunctional pressure and humidity sensor modulated by electrostatic interactions and hydrogen bonds for wearable health monitoring.

Breathing and urination, are vital physiological activities of the human body, continuous real-time monitoring of these physiological behaviors could offer timely feedback on an individual's health status. However, current monitoring techniques predominantly rely on cumbersome and intricate medical apparatuses, posing challenges in adapting to the diverse requirements of multi-scenario detection. Consequently, there is a growing interest in developing wearable devices capable of monitoring breathing and urination. In this work, we developed a multifunctional sensor integrating humidity and pressure sensing modes using a simple dip-coating process. By introducing sodium carboxymethyl cellulose and conductive polyaniline hybrid intercalation between MXene layers, a stable conductive network is established through hydrogen bonds and electrostatic interactions among materials. The overall electromechanical properties of the composites will be well improved. And, the effects of different conductive filler ratios and the number of dipping times on the construction of conductive networks are investigated. The multifunctional sensor exhibited improved sensing characteristics, including detecting pressures up to 532 kPa and a sensitivity of 19.58 kPa-1. Furthermore, it also demonstrates good humidity-sensing capabilities. Tests on volunteers demonstrated the potential in the detection of breathing and urination. In addition, the sensors are capable of transmitting Morse code. This interesting application will offer the possibility of normal communication for people with speech impairments. Given its utility and sustainability, the sensor has potential for applications in wearable health monitoring, intelligent life and telemedicine.

E242-E261 region of MYC regulates liquid-liquid phase separation and tumor growth via providing negative charges.

MYC is one of the most extensively studied oncogenic proteins and is closely associated with the occurrence and progression of many tumors. Previous studies have shown that MYC regulates cell fate through its liquid-liquid phase separation (LLPS) mechanism, which is dependent on two disordered domains within its N-terminal transcriptional activation regions. In this study, we revealed that the negatively charged conserved region (E242-E261) of the MYC protein controls its condensation formation and irreversible aggregation through multivalent electrostatic interactions (MEIs). Furthermore, deletion or mutation of the E242-E261 amino acids in the MYC protein enhances the transcriptional function of MYC by altering its aggregation capacity and subsequently promoting cancer cell proliferation. The discovery of the negatively charged region and its regulatory action on the phase separation of MYC provides a new understanding on the aggregation and function of MYC.

Ultra-Tough, yet Rigid and Healable Supramolecular Polymers with Variable Stiffness for Multimodal Actuators.

Variable stiffness materials have shown considerable application in soft robotics. However, previously reported materials often struggle to reconcile high stiffness, stretchability, toughness, and self-healing ability, because of the inherently conflicting requisite of these properties in molecular design. Herein, we propose a novel strategy that involves incorporating acid-base ionic pairs capable of from strong crosslinking sites into a dense and robust hydrogen-bonding network to construct rigid self-healing polymers with tunable stiffness and excellent toughness. To demonstrate these distinct features, the polymer was employed to serve as the strain-regulation layers within a fiber-reinforced pneumatic actuator (FPA). The exceptional synergy between the configuration versatility of FPA and the dynamic molecular behavior of the supramolecular polymers equips the actuator with simultaneous improvement in motion dexterity, multimodality, loading capacity, robustness, and durability. Additionally, the concept of integrating high dexterity at both macro- and micro-scale is prospective to inspire the design of intelligent yet robust devices across various domains.

Anchorless Bacterial Moonlighting Metabolic Enzymes Modulate the Immune System and Contribute to Pathogenesis.

Moonlighting proteins (MPs), characterized by their ability to perform multiple physiologically unrelated functions without alterations to their primary structures, represent a fascinating class of biomolecules with significant implications for host-pathogen interactions. This Review highlights the emerging importance of metabolic moonlighting proteins (MetMPs) in bacterial pathogenesis, focusing on their non-canonical secretion and unconventional surface anchoring mechanisms. Despite lacking typical signal peptides and anchoring motifs, MetMPs such as acetaldehyde alcohol dehydrogenase (AdhE) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) are secreted and localized to the bacterial surface under stress conditions, facilitating host colonization and immune evasion. The secretion of MetMPs, often observed during conditions such as resource scarcity or infection, suggests a complex regulation akin to the overexpression of heat shock proteins in response to environmental stresses. This Review proposes two potential pathways for MetMP secretion: membrane damage-induced permeability and co-transportation with traditionally secreted proteins, highlighting a remarkable bacterial adaptability. Biophysically, surface anchoring of MetMPs is driven by electrostatic interactions, bypassing the need for conventional anchoring sequences. This mechanism is exemplified by the interaction between the bifunctional enzyme AdhE (known as Listeria adhesion protein, LAP) and the internalin B (InlB) in Listeria monocytogenes, which is mediated by charged residues facilitating adhesion to host tissues. Furthermore, MetMPs play critical roles in iron homeostasis, immune modulation, and evasion, underscoring their multifaceted roles in bacterial pathogenicity. The intricate dynamics of MetMP secretion and anchoring underline the need for further research to unravel the molecular mechanisms underpinning these processes, offering potential new targets for therapeutic intervention against bacterial infections.

Recent Progress in Polyion Complex Nanoparticles with Enhanced Stability for Drug Delivery.

Polyion complex (PIC) nanoparticles, including PIC micelles and PICsomes, are typically composed of poly(ethylene glycol) block copolymers coupled with oppositely charged polyelectrolytes or therapeutic agents via electrostatic interaction. Due to a simple and rapid preparation process with high drug-loading efficiency, PIC nanoparticles are beneficial to maintaining the chemical integrity and high biological activity of the loaded drugs. However, the stability of PIC nanoparticles can be disrupted in high-ionic-strength solutions because electrostatic interaction is the DRIVING force; these disruptions can thus impair drug delivery. Herein, we summarize the advances in the use of PIC nanoparticles for delivery of charged drugs, focusing on the different chemical and physical strategies employed to enhance their stability, including enhancing the charge density, crosslinking, increasing hydrophobic interactions, forming hydrogen bonds, and the development of PIC-based gels. In particular, we describe the use of PIC nanoparticles to load peptide antibiotics targeting antibiotic-resistant and biofilm-related diseases and the use of nanoparticles that load chemotherapeutics and gaseous donors for cancer treatment. Furthermore, the application of PIC nanoparticles as magnetic resonance imaging contrast agents is summarized for the first time. Therefore, this review is of great significance for advances in the use of polymeric nanoparticles for functional drug delivery.

Single-Molecule Assessment of DNA Hybridization Kinetics on Dye-Loaded DNA Nanostructures.

DNA nanostructures offer a versatile platform for precise dye assembly, making them promising templates for creating photonic complexes with applications in photonics and bioimaging. However, despite these advancements, the effect of dye loading on the hybridization kinetics of single-stranded DNA protruding from DNA nanostructures remains unexplored. In this study, the DNA points accumulation for imaging in the nanoscale topography (DNA-PAINT) technique is employed to investigate the accessibility of functional binding sites on DNA-templated excitonic wires. The results indicate that positively charged dyes on DNA frameworks can accelerate the hybridization kinetics of protruded ssDNA through long-range electrostatic interactions. Furthermore, the impacts of various charged dyes and binding sites are explored on diverse DNA frameworks with varying cross-sizes. The research underscores the crucial role of electrostatic interactions in DNA hybridization kinetics within DNA-dye complexes, offering valuable insights for the functionalization and assembly of biomimetic photonic systems.

Directed-evolution mutations enhance DNA-binding affinity and protein stability of the adenine base editor ABE8e.

Adenine base editors (ABEs), consisting of CRISPR Cas nickase and deaminase, can chemically convert the A:T base pair to G:C. ABE8e, an evolved variant of the base editor ABE7.10, contains eight directed evolution mutations in its deaminase TadA8e that significantly increase its base editing activity. However, the functional implications of these mutations remain unclear. Here, we combined molecular dynamics (MD) simulations and experimental measurements to investigate the role of the directed-evolution mutations in the base editing catalysis. MD simulations showed that the DNA-binding affinity of TadA8e is higher than that of the original deaminase TadA7.10 in ABE7.10 and is mainly driven by electrostatic interactions. The directed-evolution mutations increase the positive charge density in the DNA-binding region, thereby enhancing the electrostatic attraction of TadA8e to DNA. We identified R111, N119 and N167 as the key mutations for the enhanced DNA binding and confirmed them by microscale thermophoresis (MST) and in vivo reversion mutation experiments. Unexpectedly, we also found that the directed mutations improved the thermal stability of TadA8e by ~ 12 °C (Tm, melting temperature) and that of ABE8e by ~ 9 °C, respectively. Our results demonstrate that the directed-evolution mutations improve the substrate-binding ability and protein stability of ABE8e, thus providing a rational basis for further editing optimisation of the system.

Heteroaggregation and deposition behaviors of carboxylated nanoplastics with different types of clay minerals in aquatic environments: Important role of calcium(II) ion-assisted bridging.

The widespread utilization of plastic products ineluctably leads to the ubiquity of nanoplastics (NPs), causing potential risks for aquatic environments. Interactions of NPs with mineral surfaces may affect NPs transport, fate and ecotoxicity. This study aims to investigate systematically the deposition and aggregation behaviors of carboxylated polystyrene nanoplastics (COOH-PSNPs) by four types of clay minerals (illite, kaolinite, Na-montmorillonite, and Ca-montmorillonite) under various solution chemistry conditions (pH, temperature, ionic strength and type). Results demonstrate that the deposition process was dominated by electrostatic interactions. Divalent cations (i.e., Ca2+, Mg2+, Cd2+, or Pb2+) were more efficient for screening surface negative charges and compressing the electrical double layer (EDL). Hence, there were significant increases in deposition rates of COOH-PSNPs with clay minerals in suspension containing divalent cations, whereas only slight increases in deposition rates of COOH-PSNPs were observed in monovalent cations (Na+, K+). Negligible deposition occurred in the presence of anions (F-, Cl-, NO3-, CO32-, SO42-, or PO43-). Divalent Ca2+ could incrementally facilitate the deposition of COOH-PSNPs through Ca2+-assisted bridging with increasing CaCl2 concentrations (0-100 mM). The weakened deposition of COOH-PSNPs with increasing pH (2.0-10.0) was primarily attributed to the reduce in positive charge density at the edges of clay minerals. In suspensions containing 2 mM CaCl2, increased Na+ ionic strength (0-100 mM) and temperature (15-55 ◦C) also favored the deposition of COOH-PSNPs. The ability of COOH-PSNPs deposited by four types of clay minerals followed the sequence of kaolinite > Na-montmorillonite > Ca-montmorillonite > illite, which was related to their structural and surface charge properties. This study revealed the deposition behaviors and mechanisms between NPs and clay minerals under environmentally representative conditions, which provided novel insights into the transport and fate of NPs in natural aquatic environments.

Heteroaggregation kinetics of oppositely charged nanoplastics in aquatic environments: Effects of particle ratio, solution chemistry, and interaction sequence.

Interactions between positively charged amino-modified (APS) and negatively charged bare (BPS) polystyrene nanoplastics may cause heteroaggregation in aquatic environments. This study investigated the effects of particle concentration ratio, solution chemistry [electrolytes, pH, and natural organic matter (NOM)], and interaction sequence on their heteroaggregation kinetics. In the absence of electrolytes and NOM, the APS/BPS ratio for attaining maximum heteroaggregation rate (khetero) increased from APS/BPS= 3/7 to APS/BPS= 1/1 as pH increased from 4 to 10, indicating that electrostatic interactions dominated heteroaggregation. In the absence of NOM, khetero ranked APS/BPS= 2/3 > APS/BPS= 1/1 > APS/BPS= 3/2. Colloidal stability decreased linearly as pH increased from 4 to 8 at APS/BPS= 1/1, while diffusion-limited heteroaggregation persisted at pH 10. In NaCl solution, humic acid (HA) retarded heteroaggregation more effectively than sodium alginate (SA) via steric hindrance and weakening electrostatic interactions, following the modified Derjaguin-Landau-Verwey-Overbeek (MDLVO) theory. Compared with simultaneous interactions among APS, BPS, NaCl, and NOM, the NOM retardation effects on heteroaggregation weakened if delaying its interaction with others. In CaCl2 solution, the effects of NOM on heteroaggregation depended on counterbalance among charge screening, steric hindrance, and calcium bridging. These findings highlight the important role of heteroaggregation between oppositely charged nanoplastics on their fate and transport in aquatic environments.

Self-Assembly of Molecular Landers Equipped with Functional Moieties on the Surface: A Mini Review.

The bottom-up fabrication of supramolecular and self-assembly on various substrates has become an extremely relevant goal to achieve prospects in the development of nanodevices for electronic circuitry or sensors. One of the branches of this field is the self-assembly of functional molecular components driven through non-covalent interactions on the surfaces, such as van der Waals (vdW) interactions, hydrogen bonding (HB), electrostatic interactions, etc., allowing the controlled design of nanostructures that can satisfy the requirements of nanoengineering concepts. In this context, non-covalent interactions present opportunities that have been previously explored in several molecular systems adsorbed on surfaces, primarily due to their highly directional nature which facilitates the formation of well-ordered structures. Herein, we review a series of research works by combining STM (scanning tunneling microscopy) with theoretical calculations, to reveal the processes used in the area of self-assembly driven by molecule Landers equipped with functional groups on the metallic surfaces. Combining these processes is necessary for researchers to advance the self-assembly of supramolecular architectures driven by multiple non-covalent interactions on solid surfaces.

Coprecipitation of Fe/Cr Hydroxides at Organic-Water Interfaces: Functional Group Richness and (De)protonation Control Amounts and Compositions of Coprecipitates.

Iron/chromium hydroxide coprecipitation controls the fate and transport of toxic chromium (Cr) in many natural and engineered systems. Organic coatings on soil and engineered surfaces are ubiquitous; however, mechanistic controls of these organic coatings over Fe/Cr hydroxide coprecipitation are poorly understood. Here, Fe/Cr hydroxide coprecipitation was conducted on model organic coatings of humic acid (HA), sodium alginate (SA), and bovine serum albumin (BSA). The organics bonded with SiO2 through ligand exchange with carboxyl (-COOH), and the adsorbed amounts and pKa values of -COOH controlled surface charges of coatings. The adsorbed organic films also had different complexation capacities with Fe/Cr ions and Fe/Cr hydroxide particles, resulting in significant differences in both the amount (on HA > SA(-COOH) ≫ BSA(-NH2)) and composition (Cr/Fe molar ratio: on BSA(-NH2) ≫ HA > SA(-COOH)) of heterogeneous precipitates. Negatively charged -COOH attracted more Fe ions and oligomers of hydrolyzed Fe/Cr species and subsequently promoted heterogeneous precipitation of Fe/Cr hydroxide nanoparticles. Organic coatings containing -NH2 were positively charged at acidic pH because of the high pKa value of the functional group, limiting cation adsorption and formation of coprecipitates. Meanwhile, the higher local pH near the -NH2 coatings promoted the formation of Cr(OH)3. This study advances fundamental understanding of heterogeneous Fe/Cr hydroxide coprecipitation on organics, which is essential for successful Cr remediation and removal in both natural and engineered settings, as well as the synthesis of Cr-doped iron (oxy)hydroxides for material applications.

Dynamic Electrostatic Interfacial Engineering for Block Copolymer Microparticles with Reversible Structures.

Responsive nanoparticle surfactants (NPSs) can dynamically and reversibly modulate the interfacial interactions between incompatible components, which are essential in the interfacial catalysis, corrosion, and self-assembly of block copolymers (BCPs). However, NPSs with stimuli-responsive behavior often involve tedious chemical synthesis and surface modifications. Herein, we propose a strategy to in situ construct a kind of dynamic and reversible NPSs by the interfacial electrostatic interaction between the negatively charged nanoparticles (NPs) and the positively charged homopolymers. The NPSs assembled at the oil/water interface reduce the interfacial tension and direct the confined assembly of BCP. Meanwhile, the dynamic NPSs can be disassembled by increasing the pH value or introducing competitive electrostatic attractions, which can dynamically and reversibly change the interfacial properties as well as the alignment of polymer chains, enabling BCP microparticles with reversibly switchable lamellar and cylindrical structures. Furthermore, by the introduction of aggregation-induced emission luminogens as tails to the NPSs, the reversible transformation of BCP microparticles can be visualized by fluorescence emission, which is dependent on the nanostructures of microparticles. This work establishes a concept for dynamically manipulating interfacial interactions and reversibly switching BCP microparticles without time-consuming NPS synthesis, showing promising applications in the fabrication of smart materials with switchable structures and properties.

Unveiling the Role of Cationic Pyridine Sites in Covalent Triazine Framework for Boosting Zinc-Iodine Batteries Performance.

Rechargeable Zinc-iodine batteries (ZIBs) are gaining attention as energy storage devices due to their high energy density, low-cost, and inherent safety. However, the poor cycling performance of these batteries always arises from the severe leakage and shuttle effect of polyiodides (I3 - and I5 -). Herein, a novel cationic pyridine-rich covalent triazine framework (CCTF-TPMB) is developed to capture and confine iodine (I2) species via strong electrostatic interaction, making it an attractive host for I2 in ZIBs. The as-fabricated ZIBs with I2 loaded CCTF-TPMB (I2@CCTF-TPMB) cathode achieve a large specific capacity of 243 mAh g-1 at 0.2 A g-1 and an exceptionally stable cyclic performance, retaining 93.9% of its capacity over 30 000 cycles at 5 A g-1. The excellent electrochemical performance of the ZIBs can be attributed to the pyridine-rich cationic sites of CCTF-TPMB, which effectively suppress the leakage and shuttle of polyiodides, while also accelerating the conversion reaction of I2 species. Combined in situ Raman and UV-vis analysis, along with theoretical calculations, clearly reveal the critical role played by pyridine-rich cationic sites in boosting the ZIBs performances. This work opens up a promising pathway for designing advanced I2 cathode materials toward next-generation ZIBs and beyond.

Single-Stranded Nucleic Acid Transmembrane Molecular Carriers Based on Positively Charged Helical Foldamers.

Transmembrane delivery of biologically active nucleic acids is an important process in cells and has inspired one to develop advanced drug delivery techniques. In this contribution, molecular-level single-stranded nucleic acid transmembrane carriers are reported based on 3.2 nm long Huc's foldamers (AOrnQ3Q3)8 and (mQ3Q2)8 with linearly and helically aligned positive charges, respectively. These two foldamers not only show very strong DNA affinity via electrostatic interactions but also discriminatively bind single-stranded DNA (ss-DNA) and double-stranded DNA (ds-DNA), corroborating the importance of precise charge arrangement in the electrostatic interactions. More importantly, these two foldamers are capable of efficiently transporting ss-DNA across the lipid membranes, and the ss-DNA transport activity of (AOrnQ3Q3)8 with linearly aligned charges is higher than that of (mQ3Q2)8 with helically aligned charges. Thus a type of novel single-stranded nucleic acid transmembrane molecular carriers based on positively charged helical foldamers are introduced. Further, effective and enhanced expression in EGFP-mRNA transfection experiments strongly demonstrates the potential of positively charged foldamers for RNA transmembrane transport and therapy.

Engineering surface framework TiO6 single sites for unprecedented deep oxidative desulfurization.

Catalytic oxidative desulfurization (ODS) using titanium silicate catalysts has emerged as an efficient technique for the complete removal of organosulfur compounds from automotive fuels. However, the precise control of highly accessible and stable-framework Ti active sites remains highly challenging. Here we reveal for the first time by using density functional theory calculations that framework hexa-coordinated Ti (TiO6) species of mesoporous titanium silicates are the most active sites for ODS and lead to a lower-energy pathway of ODS. A novel method to achieve highly accessible and homogeneously distributed framework TiO6 active single sites at the mesoporous surface has been developed. Such surface framework TiO6 species exhibit an exceptional ODS performance. A removal of 920 ppm of benzothiophene is achieved at 60°C in 60 min, which is 1.67 times that of the best catalyst reported so far. For bulky molecules such as 4,6-dimethyldibenzothiophene (DMDBT), it takes only 3 min to remove 500 ppm of DMDBT at 60°C with our catalyst, which is five times faster than that with the current best catalyst. Such a catalyst can be easily upscaled and could be used for concrete industrial application in the ODS of bulky organosulfur compounds with minimized energy consumption and high reaction efficiency.

Charge-Reversed Exosomes for Targeted Gene Delivery to Cartilage for Osteoarthritis Treatment.

Gene therapy has the potential to facilitate targeted expression of therapeutic proteins to promote cartilage regeneration in osteoarthritis (OA). The dense, avascular, aggrecan-glycosaminoglycan (GAG) rich negatively charged cartilage, however, hinders their transport to reach chondrocytes in effective doses. While viral vector mediated gene delivery has shown promise, concerns over immunogenicity and tumorigenic side-effects persist. To address these issues, this study develops surface-modified cartilage-targeting exosomes as non-viral carriers for gene therapy. Charge-reversed cationic exosomes are engineered for mRNA delivery by anchoring cartilage targeting optimally charged arginine-rich cationic motifs into the anionic exosome bilayer by using buffer pH as a charge-reversal switch. Cationic exosomes penetrated through the full-thickness of early-stage arthritic human cartilage owing to weak-reversible ionic binding with GAGs and efficiently delivered the encapsulated eGFP mRNA to chondrocytes residing in tissue deep layers, while unmodified anionic exosomes do not. When intra-articularly injected into destabilized medial meniscus mice knees with early-stage OA, mRNA loaded charge-reversed exosomes overcame joint clearance and rapidly penetrated into cartilage, creating an intra-tissue depot and efficiently expressing eGFP; native exosomes remained unsuccessful. Cationic exosomes thus hold strong translational potential as a platform technology for cartilage-targeted non-viral delivery of any relevant mRNA targets for OA treatment.

MB16 - (M=Sc, Y, La): Perfect Bowl-Like Boron Clusters.

The introduction of transition-metal doping has engendered a remarkable array of unprecedented boron motifs characterized by distinctive geometries and bonding, particularly those heretofore unobserved in pure boron clusters. In this study, we present a perfect (no defects) boron framework manifesting an inherently high-symmetry, bowl-like architecture, denoted as MB16 - (M=Sc, Y, La). In MB16 -, the B16 is coordinated to M atoms along the C5v-symmetry axis. The bowl-shaped MB16 - structure is predicted to be the lowest-energy structure with superior stability, owing to its concentric (2 π+10 π) dual π aromaticity. Notably, the C5v-symmetry bowl-like B16 - is profoundly stabilized through the doping of an M atom, facilitated by strong d-pπ interactions between M and boron motifs, in conjunction with additional electrostatic stabilization by an electron transfer from M to the boron motifs. This concerted interplay of covalent and electrostatic interactions between M and bowl-like B16 renders MB16 - a species of exceptional thermodynamic stability, thus making it a viable candidate for gas-phase experimental detection.

Achieving High-Performance Lithium-Sulfur Batteries by Modulating Li+ Desolvation Barrier with Liquid Crystal Polymers.

Lithium-sulfur (Li-S) batteries offer high theoretical capacity but are hindered by poor rate capability and cycling stability due to sluggish Li2S precipitation kinetics. Here a sulfonate-group-rich liquid crystal polymer (poly-2,2'-disulfonyl-4,4'-benzidine terephthalamide, PBDT) is designed and fabricated to accelerate Li2S precipitation by promoting the desolvation of Li+ from electrolyte. PBDT-modified separators are employed to assemble Li-S batteries, which deliver a remarkable rate capacity (761 mAh g-1 at 4 C) and cycling stability (500 cycles with an average decay rate of 0.088% per cycle at 0.5 C). A PBDT-based pouch cell even delivers an exceptional capacity of ≈1400 mAh g-1 and an areal capacity of ≈11 mAh cm-2 under lean-electrolyte and high-sulfur-loading condition, demonstrating promise for practical applications. Results of Raman spectra, molecular dynamic (MD) and density functional theory (DFT) calculations reveal that the abundant anionic sulfonate groups of PBDT aid in Li+ desolvation by attenuating Li+-solvent interactions and lowering the desolvation energy barrier. Plus, the polysulfide adsorption/catalysis is also excluded via electrostatic repulsion. This work elucidates the critical impact of Li+ desolvation on Li-S batteries and provides a new design direction for advanced Li-S batteries.

Chitosan interaction with stomach mucin layer to enhances gastric retention and mucoadhesive properties.

The interaction between mucoadhesive materials and mucin layers is of significant interest in the development of drug delivery systems and biomedical applications for effective targeting and prolonged stay in the gastrointestinal tract. In this article, the current advancement and mucoadhesive properties of chitosan concerning the stomach mucin layer and its interactions have been briefly addressed. Chitosan a biocompatible polysaccharide exhibited promising mucoadhesive properties attributed to its cationic nature and ability to establish bonds with mucin glycoproteins. The mucoadhesion mechanism is ascribed to the electrostatic interactions between the positively charged amino (NH2) groups of chitosan and the sialic acid residues in mucin glycoprotein which carry a negative charge. The article provides a succinct overview of prior uses, current trends, and recent advancements in chitosan-based gastric-targeted delivery systems. We look forward to further innovations and emerging research related to chitosan-based methods of delivery that may increase the chitosan suitability for use in novel therapeutic approaches.