Excited state intramolecular proton transfer (ESIPT) fluorescent molecules have demonstrated broad application prospects in fields of fluorescent probes, biological imaging and optoelectronic devices due to their unique advantages such as large Stokes shifts and negligible self-absorption properties. However, most ESIPT molecules are prone to fluorescence quenching in aqueous environments due to the disruption of intramolecular hydrogen bonds, which has severely limited their practical applications. Herein, the high-performance ESDPT fluorescent molecule diethyl 3,3'-dihydroxy-[2,2'-bipyridine]-5,5'-dicarboxylate (BP(OH)2DCEt2) is systematically studied. The S0 and S1 properties of the molecule in DMSO-water binary mixtures with water contents ranging from 0% to 90% are investigated using DFT and TDDFT methods in conjunction with the IEFPCM implicit solvent model. Theoretical calculations reveal that the two equivalent intramolecular O-H···N hydrogen bonds of 3,3'-dihydroxy-[2,2'-bipyridine]-5,5'-dicarboxylate are strengthened in S1 state, providing a driving force for proton transfer. All geometric and electronic structure parameters show high stability over the broad range of water fractions examined. The ESDPT reaction follows a stepwise mechanism, characterized by an exceptionally low energy barrier (<0.4 kcal/mol) for the initial proton transfer step, which occurs essentially instantaneously, and this guarantees the high efficiency of the ESIPT process. Furthermore, with increasing water content, all proton transfer pathway barriers exhibit a downward trend, which confers a modest promotional influence on the reaction kinetics. The present study systematically elucidates the underlying mechanism of the excellent water-resistant ESIPT performance of 3,3'-dihydroxy-[2,2'-bipyridine]-5,5'-dicarboxylate, and provides a solid theoretical foundation for its practical applications in aqueous environments.

Hydrogel dressings for wound management need to deliver multiple functions, such as wet adhesion, antibacterial and anti-inflammatory effects, healing, and pain relief. Integrating these functionalities to fabricate multifunctional dressings has become a major research focus. However, most existing studies concentrate primarily on combining these features without considering the activation sequence or duration of each function, which can inadvertently prolong patients' unpleasant symptoms. Properly sequencing and controllably activating these functionalities is essential to enhance patient comfort and ensure more effective wound care. Herein, we report a concept hydrogel dressing with time-dependent multilevel functions for effective wound management. The hydrogel matrix is based on gelatin methacryloyl (GelMA) with mussel-inspired phenolic groups forming a wet adhesive system. This material can adhere to irregular wounds and complex, blood-containing surfaces within 10 s, fulfilling the essential adhesion function. After bonding, the hydrogel system initiated the release of the analgesic lidocaine quickly. Meanwhile, maintaining strong adhesion and local analgesic effects, the antibacterial and anti-inflammatory agent costunolide (Cstl), encapsulated in liposomes is gradually released. This novel concept to effectively schedule different functionalities over time according to wound management and comfort needs offers a valuable design route for developing smart wound dressing materials.

Heart valve diseases cause progressive loss of function and remain a leading contributor to cardiovascular morbidity. Tissue-engineered heart valves (TEHVs) offer a potential solution, but reproducing the extracellular matrix architecture and mechanical microenvironment of native leaflets remains a critical challenge. Gelatin methacryloyl (GelMA) hydrogels provide tunable structural and mechanical properties, offering a promising platform. However, their ability to direct lineage-specific tissue reconstruction remains unclear. Here, we investigated the responses of human umbilical vein endothelial cells (HuVECs) and immortalized human aortic valve interstitial cells (iHAVICs) cultured either on the surface (2D) or encapsulated within (3D) GelMA hydrogels. Both cell types maintained high viability across dimensional culture conditions (2D and 3D). In 2D, HuVECs proliferated and assembled into highly interconnected vascular plexuses containing luminal structures, while iHAVICs formed spongy, mesh-like frameworks. In 3D, HuVECs developed complex, spatially interconnected vascular-like networks, and iHAVICs transitioned from spherical to spindle morphologies, aligning into linear and fibrous skeletons. These findings establish that GelMA substrates direct cell-type-specific morphogenesis, yielding vascular networks from HuVECs and valve-like stromal architectures from iHAVICs in a dimensionality-dependent manner. This study demonstrates the feasibility of using GelMA hydrogels to support distinct, tissue-relevant architectures, providing a basis for future strategies in TEHVs.

Impaired wound healing is primarily influenced by oxidative stress, aberrant enzyme activity, and disruption of the extracellular matrix (ECM), conditions that conventional dressings inadequately address. In contrast, adaptive hyaluronic acid (HA) hydrogels have emerged as a promising platform due to their inherent bioactivity and structural tunability. This review elucidates recent advancements in stimulus-responsive HA hydrogels, with a particular emphasis on the translation of pH, reactive oxygen species (ROS), enzymatic activity, and mechanical stimuli into network remodeling and controlled therapeutic release. Exemplary systems, such as Schiff base-based pH-responsive hydrogels, disulfide-crosslinked ROS-responsive platforms, and matrices sensitive to matrix metalloproteinases (MMPs), illustrate how structure-function relationships facilitate precise regulation of inflammation, angiogenesis, and tissue repair. Furthermore, we explore how these materials orchestrate biochemical signaling, matrix mechanics, and dynamic structural adaptation to influence ECM remodeling and cellular behavior. Finally, we outline emerging strategies, including spatiotemporal regulation, multi-signal integration, and AI-assisted design, to address existing challenges in predictability and clinical translation. This review provides a design-oriented perspective for developing next-generation adaptive hydrogels for precise regenerative medicine.

Improving the high physical stability of Pickering emulsions, while maintaining their low viscosity, faces enormous challenges. In this study, DAC-OVA conjugates (D-OVA) was prepared using dialdehyde cellulose ovalbumin (OVA) via a Schiff base reaction. Then, the characterization of the D-OVA stabilized Pickering emulsions (DPE) were studied. The results showed that the particle size of DAC was decreased, and the initial morphology disappeared after OVA modification. Compared with OVA-stabilized Pickering emulsion (OPE), the zeta potential of DPE increased significantly at different pH values, especially at pH 4.6 and pH 7.0, which increased about 2.2 and 3.5 times, respectively. Scanning electron microscopy revealed that D-OVA formed a rigid film at the oil-water interface, and DPE droplets exhibited homogeneous dispersion. The rheological results demonstrated that the viscosity of DPE remained consistently low across varying pH and high temperature conditions. Compared with OPE, the freeze-thaw, thermal, and storage stability of DPE have significantly improved.

The exploration of non-Pt catalysts that are highly efficient, durable, and cost-effective for the hydrogen evolution reaction (HER) is crucial for enhancing the energy efficiency of water splitting technologies. In this study, we fabricated an electrocatalyst comprising RuP2 nanoparticles decorated on N, P codoped cellulose nanofibers (CNFs)-derived carbon networks (RuP2/NPC) through a simple mixing-pyrolysis strategy. Specifically, the CNFs, which are rich in oxygen-containing functional groups, not only serve as dispersants to prevent the restacking of graphene oxide (GO) and the aggregation of RuP2 nanoparticles, thereby exposing more active sites, but also form a conductive network with GO to facilitate electron transport. Moreover, density functional theory (DFT) calculations indicate that the integration of NPC regulates the electronic structure of RuP2, resulting in a nearly thermoneutral Delta G H* at the Ru site of RuP2/NPC and making the HER process more feasible. Consequently, the synthesized catalyst exhibits excellent catalytic activity, achieving low overpotentials of 41 mV in 0.5 M H2SO4 and 52 mV in 1.0 M KOH to drive a current density of 10 mA cm-2, while maintaining robust stability. Notably, RuP2/NPC also demonstrates promising performance in alkaline seawater electrolysis, requiring an overpotential of merely 108 mV to support the same level of current density. This research significantly advances the application of CNFs-derived carbon materials in hydrogen production and contributes to the high-value utilization of forestry resources, thereby providing an inspiring avenue for the advancement of efficient and sustainable energy conversion technologies.

Janus membranes exhibit notable benefits in enhancing the anti-fouling ability during membrane distillation (MD). However, the bonding stability between the hydrophilic layer and the hydrophobic matrix is a worrying concern. In this work, we developed an interfacial free radical polymerization (IFRP) method by segregating photoinitiator and polyethylene glycol diacrylate (PEGDA) monomers into the oil and water phases, respectively. This approach facilitated a crosslinking reaction initiated at the oil-water interface, leading to the formation of a discontinuous or continuous hydrogel-like coating on one side of the PVDF membrane within a 30-second lightinduced reaction. The PEGDA gel filled the membrane pores rather than growing outward along its surface, thus creating a "physical interlocking" effect and significantly enhancing their bonding stability. Anti-fouling and anti-wetting experiments were conducted under harsh conditions, including hypersaline solution of 20 wt%, high oil-content saline emulsion and humic acid/CaCl2 mixed brine. Results demonstrated stable water vapor flux and salt rejection. By increasing the molecular weight of PEGDA monomers, a dense gel layer can be conveniently obtained, which can withstand high-concentration surfactant. This proposed IFRP method offers strong customizability, enabling the efficient production of either porous or dense hydrophilic layers to adapt to various salt solutions.

The disruption of endogenous electric field (EF) and subsequent degradation of the extracellular matrix (ECM) and joint wear are the fundamental pathological mechanisms underlying Osteoarthritis (OA). The key to reversing OA and promoting cartilage repair lies in restoring the endogenous electric field, improving lubrication performance between articular cartilage, and achieving a catabolic balance of ECM. In this study, we utilized short fiber fabrication technology and surface dopamine grafting technology to construct a "PLA/Gel@beta-Gly/rG/ PMPC" lubricated electroactive short fiber. By utilizing an "ultrasonic piezoelectric transducer" to generate electrical signals, we promoted ECM synthesis, restored endogenous EF, repaired hydration lubrication layer, and stabilized the endogenous electric field. This approach enables regeneration and optimization of articular cartilage while breaking free from the detrimental cycle associated with OA. Under ultrasonic stimulation at 1 W, 650 kHz frequency, and 50 % duty cycle, the lubricated electroactive short fiber generated a significant electrical signal of 1.31 V which upregulated Sirt1 expression in OA chondrocytes. It improved mitochondrial function and increased ATP capacity to 23.074 +/- 1.87 pmol/min. Furthermore, incorporating different proportions of lubricating molecules (1:1, 1:4, and 1:8) into the material reduced the coefficient of friction (COF) between articular cartilages from approximately 0.725-0.693 to about 0.235. This improvement enhanced lubrication performance between articular cartilages by inhibiting ECM degradation and stabilizing endogenous EF. The innovative composite electrospun material exhibits great potential in promoting OA cartilage repair.

Converting CO2 into valuable chemicals through photocatalytic reduction is a promising method to achieve carbon neutrality. Nonetheless, the insufficient active sites of photocatalysts lead to low CO2 reduction efficiency and product selectivity. Taking advantage of the synergistic effect of photocatalytic heterostructures is an effective way to overcome this shortcoming. Here, metal-organic frameworks (MIL-101(Cr))-titanium dioxide (TiO2) staggered gap (type II) heterojunctions were deposited on different woven polyimide (PI) substrates (MIL101-TiO2 PI hybrid photocatalysts) via atomic layer deposition and hydrothermal reaction for CO2 photoreduction. The immobilized photocatalysts on the PI substrates resolved the challenge of separating powdered photocatalysts from liquid products or reactants. The prepared MIL-101(Cr)-TiO2 PI hybrid photocatalysts displayed synergistic photocatalytic reduction performance towards CO2 by separating the photogenerated charge carriers. The charge transfer between the heterojunctions and the substrates extended the lifetime of the excited electrons and holes, thereby generating synergy effects and promoting the CO2 reduction yield. The rougher surface and higher specific area of the PI felt enabled higher loadings of heterojunctions compared with other woven structures of the fabric and mat. As a result, MIL-101(Cr)-TiO2 PI felts showed multiple reduction pathways over the heterostructures and enhanced photocatalytic performance, with the main product yields of 29.6, 9.2, and 0.8 mu mol g- 1 h- 1 for CO, CH4 and H2, respectively. Meanwhile, CO selectivity of the MIL-101(Cr)TiO2 PI felt reached as high as 75 %. This study provides significant insights into the role of the substrate in flexible and immobilized hybrid photocatalysts with synergistic performance to achieve enhanced CO2 reduction yield.

Triboelectric nanogenerators (TENG) possess significant potential and offer a wide range of applications to harness low frequency micro energy from the environment. However, TENG faces challenges related to the weak tightness of bipolar materials, low charge density, and so on. In this paper, we present a novel TENG, utilizing a 0.1 mm thick nylon film as the positive electrode material and a porous material composed of PDMS/MnCO3 modified by dopamine (PDA) and Ag NWs as the negative electrode material. The sacrificial material, MnCO3, was employed to create dense internal pores within the substrate material, PDMS, resulting in a highly porous PDMS (PPDMS) substrate. The triboelectric layer of TENG resembles a sponge with 20-40 mu m pores, filling the PPDMS with high dielectric constant silver nanowires (Ag NWs) effectively enhances surface charge on the triboelectric material, leading to improved output performance. The modified TENG, based on PDMS/PDA/Ag NWs (PPA) achieves an 80 V open circuit voltage, 70.4 mW/m2 effective output power density, and sustains 10,000 contact separations without damage. Finally, energy collection devices for ocean-ball and human walking scenarios with the PPA/nylon-based TENG are designed and fabricated. The PPA/nylon-based TENG exhibits promising potential for collecting, converting, and storing clean energy.

Flexible zinc-ion batteries (FZIBs) offer great promise for wearable energy storage systems due to their safety, environmental friendliness, and low cost. Zinc powder (ZnP) stands out as a promising anode material for FZIBs due to its high surface area, low cost, and good compatibility. However, it suffers from dendrite formation, severe corrosion, and poor structural integrity. Here, a high-performance flexible zinc anode is reported by encapsulating ZnP within a thermoplastic polycarbonate-based polyurethane (TPCU) matrix featuring zincophilic and hydrophobic properties and integrating it with a MXene-coated silk fabric (MXS) current collector. The synergistic integration of TPCU and MXS enables uniform and dendrite-free Zn deposition, suppresses corrosion, and provides excellent mechanical flexibility. The resulting flexible anode achieves long cycling stability exceeding 2500 h at 1 mA cm-2 for 1 mAh cm-2 and a Coulombic efficiency of 99.75% at 5 mA cm-2 for 1 mAh cm-2. When paired with a flexible cathode, the fabricated FZIB delivers stable performance to power devices under continuous mechanical deformations, highlighting its potential for flexible energy storage applications. This work presents a feasible approach for constructing robust ZnP-based anodes for the development of next-generation FZIBs.

A chiral Brønsted acid-catalyzed asymmetric cascade aza-Piancatelli rearrangement/intramolecular Diels-Alder reaction has been developed. This method enables the atom- and step-efficient synthesis of chiral aza-[5,6,5]-tricyclic derivatives with multiple contiguous stereocenters in a highly enantioselective manner from readily available N-pentadienylanilines and 2-furylcarbinols.

The long-term survival of allografts is primarily compromised by immune rejection, in which M1 macrophage-mediated tissue damage and effector T cell infiltration have been identified as major contributors. Current clinical immunosuppressive drugs face critical limitations, as they either fail to coordinately regulate these two immune cell populations or induce systemic infections and metabolic disorders. To address this challenge, we developed an aminooxyacetic acid (AOAA)-loaded hydrogel delivery system (AOAA-Gel) based on covalently cross-linked oxidized sodium alginate/carboxymethyl chitosan (OSA/CMCS). This hydrogel enables localized and sustained AOAA release, while avoiding systemic toxicity. Mechanistically, AOAA-Gel coordinately modulates the M1/M2 macrophage ratio while expanding regulatory T cells at the graft site, resulting in effective suppression of both effector T cell infiltration and chronic rejection. In a murine allogeneic skin transplantation model, AOAA-Gel establishes an immunosuppressive microenvironment, significantly prolonging graft survival. These findings demonstrate a potentially safer therapeutic strategy for maintaining sustained allograft function through localized immunomodulation.

An effective and rapid hemostatic material with flexible properties for clinical wound dressings is still an unmet need. Herein, a porous sodium carboxymethyl starch (CMS-Na-P) hemostatic microsphere was successfully fabricated through polysaccharide fluffy aggregate (PSFA) technology with a facile and low-cost process. CMS-Na-P exhibited rapid water absorption capabilities alongside favorable cytocompatibility and hemocompatibility. Additionally, CMS-Na-P could absorb red blood cells (RBCs), adhere to and activate platelets, and shorten clotting time in vitro. More importantly, its good in vivo hemostatic ability was further demonstrated against hemorrhage in rat liver and tail, pig superficial skin, superficial body vein, superficial abdominal vein, and femoral artery. Meanwhile, in a rat full-thickness skin defect model, CMS-Na-P could enhance wound healing through accelerated epidermal regeneration and collagen deposition. These properties make CMS-Na-P a promising candidate for treating bleeding and full-thickness wounds.

(1) Background: Osteonecrosis of the femoral head (ONFH), caused by insufficient blood supply, leads to bone tissue death. Current treatments lack effective bone regeneration materials to reverse disease progression. This study introduces an injectable and self-setting 3D porous bioceramic scaffold (Mg@Ca), combining MgO + SiO2 mixtures with α-hemihydrate calcium sulfate, designed to promote bone repair through in situ pore formation and osteoinduction. (2) Methods: In vitro experiments evaluated human bone marrow mesenchymal stem cell (h-BMSC) proliferation, differentiation, and osteogenic marker expression in Mg@Ca medium. Transcriptome sequencing identified bone development-related pathways. In vivo efficacy was assessed in a rabbit model of ONFH to evaluate bone repair. (3) Results: The Mg@Ca scaffold demonstrated excellent biocompatibility and supported h-BMSC proliferation and differentiation, with significant up-regulation of COL1A1 and BGLAP. Transcriptome analysis revealed activation of the PI3K-Akt signaling pathway, critical for osteogenesis. In vivo results confirmed enhanced trabecular density and bone volume compared to controls, indicating effective bone repair and regeneration. (4) Conclusions: The Mg@Ca scaffold offers a promising therapeutic approach for ONFH, providing a minimally invasive solution for bone defect repair while stimulating natural bone regeneration. Its injectable and self-setting properties ensure precise filling of bone defects, making it suitable for clinical applications.

Amorphous assembling of SiO2 colloidal spheres is a convenient strategy to obtain amorphous photonic structure, such structure, referred to as SiO2 amorphous colloidal arrays (ACAs), can demonstrate angle-independent structural color owing to constructive interference. To date, an empirical equation for materials researchers to design the color of SiO2 ACAs remains vacant, and several influence factors concerning with the color of SiO2 ACAs are still ignored and uninvestigated. Herein, based on single scattering model, we have proposed an empirical equation to predict the reflection peak of SiO2 ACAs to design their color, and influence factors including background and thickness on the color of SiO2 ACAs were also investigated. By preparing spheres within the designed range as building blocks, SiO2 ACAs with colors varying from blue to red were achieved whose reflection peaks position fits well with the empirical equation. This study can help materials researchers to design and manipulate structural color of SiO2 ACAs while providing insight to understand the origin of structural color of SiO2 ACAs.

Amorphous arrays assembled from colloidal microspheres are a way that obtains angle-independent structural colors. In order to obtain additional properties, colloidal microspheres, which are constituent units, can be modified with other materials. Here, we utilized the silane-functionalized carbon quantum dots (SiCDs) by incorporating them into the St & ouml;ber reaction to fabricate Fe3O4@SiO2/SiCDs nanospheres with a core-shell structure. Amorphous colloidal arrays (ACAs) were constructed on commercial printing paper using Fe3O4@SiO2/SiCDs nanoparticles as structural units by a simple permeation assembly. Macroscopically, the prepared ACAs exhibit the magnetic properties of Fe3O4, while under sunlight, they display bright, angle-independent structural colors. Under ultraviolet light, the array shows significant fluorescence. This enables the presentation of multidimensional information under varying magnetic and lighting conditions. By adjusting the thickness of the outer SiO2/SiCDs composite layer, the optical properties and magnetism can be controlled easily. Moreover, due to the strong light absorption capability and high refractive index of Fe3O4, the digital patterns constructed with Fe3O4@SiO2/SiCDs nanospheres demonstrate excellent multi-level anti-counterfeiting characteristics, even under water exposure. The magnetic properties of Fe3O4@SiO2/SiCDs nanospheres, along with their distinct display characteristics under different optical environments, suggest their wide applicability in the fields of multifunctional anti-counterfeiting pigments, bioimaging, and sensing displays.

Polycaprolactone (PCL) scaffold is a common biological material for tissue engineering, owing to its good biocompatibility, biodegradability and plasticity. However, it is not suitable for osteoblast adhesion and regeneration of bone tissue due to its non-biological activity, poor mechanical strength, slow degradation speed, smooth surface and strong hydrophobicity. To improve the mechanical properties and biocompatibility of PCL scaffold, the PCL/nHA scaffolds were prepared by melting and blending different proportions of nano-hydroxyapatite (nHA) with PCL by the near-field direct-writing melt electrospinning technology in this study. The morphology, porosity, mechanical properties and in vitro biocompatibility of the PCL/nHA scaffolds were studied. The results showed that when the proportion of nHA was less than or equal to 25%, PCL/nHA composite scaffolds were easily formed in which bone marrow mesenchymal stem cells proliferated successfully. When the proportion of nHA was 15%, the PCL/nHA composite scaffolds had excellent structural regularity, good fiber uniformity, outstanding mechanical stability and superior biocompatibility. The PCL/nHA composite scaffolds were ideal scaffold materials, which would broaden their applications for bone tissue engineering.

As an emerging 3D printing technique, melt electrospinning writing (MEW) has been used to fabricate scaffolds with controllable structure and good mechanical strength for bone regeneration. However, how to further improve MEW scaffolds with nanoscale extracellular matrix (ECM) mimic structure and bioactivity is still challenging. In this study, we proposed a simple composite process by combining MEW and solution electrospinning (SE) to fabricate a micro/nano hierarchical scaffold for bone tissue engineering. The morphological results confirmed the hierarchical structure with both well-defined MEW microfibrous grid structure and SE random nanofiber morphology. The addition of gelatin nanofibers turned the scaffolds to be hydrophilic, and led to a slight enhancement of mechanical strength. Compared with PCL MEW scaffolds, higher cell adhesion efficiency, improved cell proliferation and higher osteoinductive ability were achieved for the MEW/SE composite scaffolds. Finally, multilayer composite scaffolds were fabricated by alternately stacking of MEW layer and SE layer and used to assess the effect on cell ingrowth in the scaffolds. The results showed that gelatin nanofibers did not inhibit cell penetration, but promoted the three-dimensional growth of bone cells. Thus, the strategy of the combined use of MEW and SE is a potential method to fabricate micro/nano hierarchical scaffolds to improve bone regeneration.

Rhodium-catalyzed ortho-amidations of sulfoximines lead to key intermediates for the preparation of thiadiazine 1-oxides.