Myocardial infarction (MI) progresses through a series of distinct pathological stages, from acute ischemia and reperfusion injury to chronic inflammation, fibrotic proliferation, and ventricular remodeling, each characterized by a unique combination of microenvironmental cues and therapeutic demands. Traditional injectable hydrogels, designed primarily as passive mechanical fillers, largely fail to adapt to these stage-specific needs: their fixed degradation, mechanics, and drug release profiles cannot match the dynamic post-MI milieu. Microenvironment-responsive hydrogels, by sensing signals such as reactive oxygen species (ROS), pH changes, and matrix metalloproteinases (MMPs), offer a means to align hydrogel behavior more closely with pathological progression. While existing reviews have catalogued these systems by their response mechanisms, this review takes a pathology-driven perspective. We first analyze the evolving microenvironmental characteristics and repair requirements across the major phases of MI. Then, rather than organizing the discussion by stimulus type, we examine how hydrogel properties, including responsiveness, mechanical support, electrical conductivity, and degradation, can be rationally combined with appropriate delivery formats (injectable hydrogels, cardiac patches, and composite constructs) and clinical workflows to address phase-specific therapeutic objectives. Finally, we identify bottlenecks that currently prevent these materials from reaching clinical application and outline practical strategies for overcoming them. By linking material design directly to stage-specific pathology, this review aims to offer a more clinically relevant framework for developing next-generation responsive hydrogels for MI repair. STATEMENT OF SIGNIFICANCE: Myocardial infarction (MI) is a leading cause of heart failure. Revascularization improves survival, yet reperfusion injury and remodeling drive long-term mortality. Traditional injectable hydrogels are passive fillers that cannot adapt to the post-infarction microenvironment. Most reviews classify responsive hydrogels by chemical trigger, separating material design from clinical pathology. We take a different view, linking hydrogel design to the four phases of MI healing. For each phase we identify the microenvironmental signals, then show how reactive oxygen species (ROS), pH and matrix metalloproteinase (MMP) responsiveness, mechanics, conductivity, and degradation can be combined for stage-specific therapy. We also examine how injectable hydrogels, epicardial patches, and composite constructs integrate with percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) workflows. This pathology-matched framework highlights translational bottlenecks and strategies to bridge materials science and clinical application.

Covalent organic frameworks (COFs) have emerged as promising electrocatalysts for energy conversion owing to their high specific surface area, tunable structure, and excellent chemical stability. Herein, a series of porphyrinbased COF-366 catalysts (NiCo@COF-366) were rationally designed and synthesized via Schiff-base condensation with different Ni/Co molar ratios. The as-prepared NiCo@COF-366 exhibits permanent microporosity with a large BET surface area of 954.95-1077.27 m2 g-1, as well as outstanding thermal and chemical stability. Electrochemical measurements reveal that the NiCo(1:1)@COF-366 catalyst displays optimal oxygen evolution reaction (OER) performance in 1.0 M KOH, delivering an overpotential of 410 mV at 10 mA cm-2 and a Tafel slope of 62 mV dec-1, outperforming its monometallic and other bimetallic counterparts. Direct carbonization at 900 degrees C for 9 h further boosts OER activity remarkably, achieving a low overpotential of 325 mV, a small Tafel slope of 47 mV dec-1, and outstanding long-term durability with only 3 % current decay after 24 h. The enhanced performance arises from bimetallic synergistic effects, high active-site exposure, and improved conductivity after carbonization. This work provides a feasible strategy for designing high-efficiency bimetallic porphyrin COF electrocatalysts and extends the application of COFs in solid-state energy conversion materials.

Developing efficient photocatalysts for visible-light-driven hydrogen evolution is crucial for sustainable energy conversion. Herein, a series of D-π-A-structured calixarene dyes (BFT-1COOH, BFT-2COOH, BFT-CNCOOH) with varied π-bridges and acceptor groups are molecularly engineered and integrated with Pt-loaded UiO-66-NH2 (Pt@U6N) to enhance photocatalytic hydrogen production. Systematic characterizations confirm the structural integrity of the composites and reveal reduced charge recombination due to hydrogen bonding between the dye carboxyl groups and U6N. The BFT-1COOH/Pt@U6N composites exhibit the highest hydrogen evolution rate of 1160 μmol g-1 h-1 under visible light, outperforming analogs with extended π-bridges (BFT-2COOH) or cyanoacetic acid acceptors (BFT-CNCOOH), which can be attributed to optimal LUMO energy alignment and robust dye-MOF interactions. This work underscores the significance of rational molecular engineering in balancing light absorption, electron injection driving force, and interfacial stability for advancing dye-sensitized MOF photocatalysts toward solar-to-hydrogen energy conversion.

Correction for ‘Dye-sensitized photoelectrochemical cells constructed using metal-free perylene diimide-based oxygen production polymers and calixarene dyes’ by Xiao-Lin Wang et al. , J. Mater. Chem. A , 2024, 12 , 22101–22111, https://doi.org/10.1039/d4ta03712j.

Conventional mechanochromic photonic crystals (MPCs) have attracted broad interest because of their force-adjustable reflective structural colors, which require three-dimensional and nonclose-packing structures. Here, a new type of MPC with monolayer close-packing structures, brilliant iridescent scattering structural colors, and unconventional mechanochromic properties has been fabricated by self-assembling ZnS particles into a layer of polycrystalline structures and then infiltrating interparticle gaps with elastic polyurethane (PU). The scattering light diffracted in the forward direction and high diffraction efficiency by the large refractive index contrast between ZnS particles and PU contributes to a high scattering color saturation. The MPC shows interesting mechanochromic scattering structural colors with the color red-shifted and blue-shifted along and perpendicular to the stretching directions, originating from the unique crystal orientation-dependent deformation. This work upgrades the basic understanding of the relationship between structures and optical properties and offers a perspective for designing advanced stimulus-responsive photonic materials.

Lithium-sulfur batteries (LSBs) are considered one of the most promising energy storage technologies due to their high specific capacity and energy density. Nonetheless, their practical applications are hindered by the shuttle effect and slow redox kinetics of lithium polysulfides (LiPSs). Recently, metal-organic frameworks (MOFs) have emerged as highly effective multifunctional components for addressing these issues. Thanks to their high porosity, customizable structure, and ease of functionalization, MOFs can effectively suppress the shuttle effect and enhance the electrochemical performance of LSBs. This review summarizes recent advancements in the application of MOFs in LSBs, focusing on four key areas: spatial constraint, chemical binding, catalytic conversion, and ion transport. Additionally, we will address the opportunities and challenges associated with integrating MOFs into LSBs. This review aims to provide valuable insights for the rational design of novel MOFbased components for LSBs.

Electrically responsive photonic crystals (ERPCs) capable of adjusting their structural colors in response to electric fields are promising next-generation smart optical materials. However, the poor color saturation and stability of conventional ERPCs significantly limit their practical applications. Here, a new kind of ZnS-silica/diethylene glycol ERPC was designed and fabricated by directly non-close-assembling ZnS-silica core-shell particles with high refractive indexes into a diethylene glycol with a low dielectric constant. Compared to traditional ERPCs, the as-fabricated ERPC exhibits: 1) brilliant structural colors and broad photonic bandgaps, owing to the large refractive index contrast; and 2) good stability under voltages, improved at least two magnitude, due to the combined intense solvation repulsion and enhanced electrostatic repulsion. This work provides new insight for designing and fabricating advanced ERPCs and will promote their practical applications in low-power displays, anti-counterfeiting, and optical devices.

Research on the catalytic chemistry of lithium sulfur batteries (LSBs) primarily focuses on the development of catalytic active sites, with limited attention given to their structural stability. Furthermore, regulating the nanostructure of catalysts can enhance structural stability without compromising their intrinsic catalytic activity. This work presents a covalent organic framework (COF) with dual redox-active sites (C & boxH;O and C & boxH;N) and large periodic pi-conjugated framework (denoted as CON-COF). This framework is constructed through molecular engineering to mitigate the shuttling of lithium polysulfides (LiPSs), accelerate their conversion, regulate lithium ions (Li+) dynamics, prevent dendrite formation, and maintain structural stability during cycling. Subsequently, CON-COF is in situ grown on carbon nanotubes to enhances electrical conductivity and further improves structural stability. This combination significantly boosts the performance of LSBs, achieving a remarkable decay rate of 0.021% over 1000 cycles, along with an areal capacity of 8.3 mAh cm-2 under lean electrolyte conditions. Furthermore, pouch cells incorporating this configuration demonstrate exceptional long-term stability, maintaining performance over 200 cycles. This strategy addresses the limitations of traditional catalyst design by effectively regulating both the redox-active sites and nanostructures, paving the way for the future development of high-performance LSBs.

Conventional thermochromic photonic crystal (TPC) hydrogels and liquids have gained prominence due to their unique capability of adjusting their colors by temperature (T). However, challenges including non-recordable structural colors, poor stability, and limited color tunability significantly limit their advanced applications. To address these issues, a versatile pressure-stored TPC (PSTPC) with repeatable fixable compressed non-close-packing structures has been fabricated based on combining phase-changing materials and elastic photonic crystals. Distinguishing from conventional TPCs, PSTPCs possess 1) recordable colors with excellent stability under normal conditions; 2) adjustable colors from red to blue by simply altering storable pressure; and 3) a T-triggered color change by releasing the pressure. These PSTPCs have been experimentally proved to be ideal candidates for various applications, including hot warning labels, ink-free rewritable papers, and elaborate anti-counterfeiting tags. This work offers a new perspective for designing and fabricating combined materials-based stimulus-responsive structural color materials with advanced multifunctional applications.

The application of metal-free photosensitizers in dye-sensitized photoelectrochemical cells (DSPECs) has attracted great interest due to their low cost in recent years. However, there is an urgent need to develop novel metal-free water oxidation catalysts (WOCs) for DSPECs. In this work, for the first time, three linear conjugated oxygen-producing polymers (OPPs) are introduced into the DSPEC system with calixarene photosensitizers to achieve visible light-driven total water splitting. The best performance is demonstrated by the FTO|TiO2|C4EOP + Oxamide-PDI photoanode, giving a photocurrent density of 208 mu A cm-2 after 200 s of chopping irradiation at 0.2 V vs. the reversible hydrogen electrode (RHE). Further, Faraday efficiencies of 86.1% at 0.2 V vs. RHE and 66.3% without a bias voltage for oxygen production are obtained. C4EOP-sensitized electrodes exhibit higher photocurrent densities due to their superior light absorption performance, greater electron-hole recombination impedance, and stronger affinity to hydrophilic polymers. Oxamide-PDI loaded electrodes show better performance due to their higher crystallinity and larger pi-conjugation width. This is a pioneering study to incorporate OPPs as WOCs into the calixarene-sensitized DSPEC system, which has significant potential as a low-cost and high-efficiency device for photoelectrochemical water splitting. Calixarene dyes and perylene diimide-based oxygen production polymers are attached to TiO2 thin films to create, for the first time, a dye-sensitized photoelectrochemical cell for pure light-driven water splitting.

Poly(lactic acid) (PLA) is the most promising candidate for biobased and biodegradable plastic which combines biocompatibility, renewability as well as excellent processability. However, toughening is still needed for PLA as to obtain materials suitable for broader applications. In this work, long-chain branched random copolymers poly (lactic acid-r-malic acid) (PMLA) were synthesized based on bio-resourced lactic acid (LA) and malic acid (MA) through polycondensation as toughening agent for PLA. The chemical structures of PMLA were characterized by 1H NMR and 1H-13C HSQC analysis. In the PLA and PMLA blends, PMLA has apparent effect on the crystallinity of PLA and the blends show a great increase of elongation at break to over 300 % even at low PMLA content of 2%wt. Furthermore, the thermal properties of the blend are characterized through DSC and the micro-structure investigated through Positron annihilation lifetime spectroscopic (PALS) technique. PMLA with long-chain branched topology shows an excellent capability in the toughening of PLA and maintains the total biodegradability of the resultant blend at the same time, that is critical for environment-friendly materials.

Fabricating photonic crystals (PCs) with dynamic multi-stimuli-responsive structural colors, recordable colors, and self-healable properties is significant for their emerging applications, yet remains a big challenge. Here, an all-in-one multifunctional PC (MFPC) film with outstanding mechanochromic, thermochromic, solvatochromic, color/shape-recordable, self-healable, and adhesive functions is designed and prepared by simply non-close-assembling silica particles into the unique 2-[[(Butylamino)carbonyl]oxy]ethyl acrylate (BCOEA) followed by photopolymerization. The success is mainly due to the rational combination of non-close-packing structures and BCOEA's characteristics, including its urethane groups with numerous sacrificial hydrogen bonds, temperature-dependent refractive index, swellable and deformable polymer network, as well as low glass-transition temperature. The MFPC's hue and color saturation can be reversibly and dynamically modulated by strain/pressure/solvents and temperature, respectively, thereby realizing visually and spectrally sensing these stimuli. More interestingly, the color-responsiveness combined with other functions endows MFPCs with fascinating emerging applications, including multilayer optical filters, inkless printing, reconfigurable multicolor patterns, stretching-based anti-counterfeiting, etc. This work offers a new perspective for designing next-generation smart photonic materials and will facilitate their all-round applications. Multifunctional photonic crystals with remarkable mechanochromic, thermochromic, solvatochromic, color/shape-recordable, self-healable, and adhesive functions have been fabricated by non-close-assembling silica particles into the unique commercially available 2-[[(Butylamino)carbonyl]oxy]ethyl acrylate with abundant stimuli-responsive and chemical/physical properties. These functions result in interesting emerging applications of photonic crystals, including multilayer optical filters, inkless printing, reconfigurable multicolor patterns, stretching-based anti-counterfeiting, etc. image

It is challenging for traditional smart windows to possess both high optical transparency (90%, 380-780 nm) and brilliant colors since they are usually contradictory to each other. Here, novel liquid thermal-responsive smart windows (TSWs) exhibiting high optical transparency (94%), bright iridescent forward scattering structural color, and extremely weak reflective structural colors are fabricated by constructing a refractive index (RI)-matched non-close-packing ordered structure with large lattice distances and thus unique light diffraction mechanisms. The transmittance (24-94%) and dual-mode structural color saturation (1-55 times) can be dynamically regulated by simply altering temperatures (20-100 degrees C), which can be attributed to the temperature-dependent light diffraction and scattering efficiency. A new information encryption-decryption technique is developed by combining TSWs with outstanding shapeability, recyclability, and flowability. The information is hidden under normal conditions, while 76 different pieces of information can be decrypted in programmable ways under different stimuli, showing their potential in anti-counterfeiting and information encryption. A novel liquid thermal-responsive smart window (TSW) is developed by constructing a refractive index-matched non-close-packing ordered structure with large lattice distances and thus unique light diffraction mechanisms. TSW exhibits high optical transparency (94%), bright iridescent forward scattering structural color, and extremely weak reflective structural colors at room temperature and can be dynamically regulated by simply altering temperatures.image

Supported cobalt catalysts have attracted more and more attention for their easy separation and recyclability. Herein, cobalt-embedded pyridine functionalized polystyrene superfine fibers were readily fabricated by electrospinning. Then, the pyridine functionalized polystyrene and polystyrene molecules inside the fibers were cross-linked by paraldehyde to improve the fiber stability. The synthesis of pyridine functionalized polystyrene and cross-linking of polystyrene molecules inside the fibers were confirmed by FT-IR spectra. The fiber morphologies were characterized by SEM. The dispersion of cobalt species was analyzed by SEM–EDS, XRD and TEM. Finally, the Heck reactions were employed to evaluate the catalytic performance of this novel fibrous catalyst. The catalysis results show that this novel fiber catalyst exhibited excellent catalytic activity for the Heck reactions of aromatic iodides with alkenes to afford coupling products with yields over 80

Photonic crystals (PCs) have attracted great interest and wide applications in displays, printing, anticounterfeiting, etc. However, two main challenges significantly hinder their applications: 1) the tradeoff between high optical transparency across the whole visible range and brilliant colors requiring a large refractive index contrast (Delta n), and 2) the way of regulating structural colors by altering tens of different sizes. To address these issues, a new type of metal-organic framework (MOF)-based transparent photonic crystal (TPC) has been fabricated through self -assembling MOF particles into three-dimensional ordered structures which were then infiltrated by polydimethylsiloxane (PDMS). Compared to conventional PCs, these TPCs exhibit 1) both brilliant forward iridescent structural colors and high transmittance (>75 %) across the whole visible spectra range, and 2) conveniently adjustable colors based on bidisperse particles. The unique color -generating mechanism of the light diffraction by each plane lattice and the small Delta n between MOF particles and PDMS are the keys to TPCs' characteristics. Moreover, the prepared invisible anti -counterfeit labels can reversibly hide -reveal patterns with elaborate and exchangeable color contrast in a non-destructive way, showing potential applications in anticounterfeiting, information encryption, and optical devices.

Overall water splitting into H-2 and H2O2 via Z-scheme piezo-photocatalytic systems is an ideal method for renewable energy production. Herein, we have synthesized a triangular prism-shaped metal-organic cage (MOC-Q3) integrating three catalytic Pd2+ centers and two photosensitive ligands, which is successfully immobilized on a highly crystalline beta-ketoenamine-linked covalent organic framework (EA-COF) to form a Z-scheme single-atom photosystem. The optimized MOC-Q3/EA-COF achieves a high H-2 yield (26.17 mmol g(-1) h(-1)) with a TONPd of 118,521 with ascorbic acid as sacrificial agent due to broad light absorption, effective carrier separation, and widely distributed Pd active sites, which is among the highest for COF-based solar H-2 evolution photocatalysts. Interestingly, EA-COF is found to be a piezoelectric material and its piezoelectric performance is mainly due to the in-plane polarization of the 2,4,6-trihydroxybenzene-1,3,5-tricarbaldehyde groups in the COF, which is confirmed by experimental observations and density functional theory calculations. The EA-COF shows H-2 and H2O2 production rates of 239.94 and 400.38 mu mol g(-1) h(-1), respectively, in pure water when excited by ultrasound coupled with light irradiation. The integration of MOC-Q3 can further enhance the efficiency of EA-COF in piezo-photocatalytic water splitting. The superior MOC-Q3/EA-COF exhibits H-2 and H2O2 generation rates of 426.38 and 535.14 mu mol g(-1) h(-1), respectively, outperforming pure EA-COF by 1.8 and 1.3 times. This is a pioneering work to construct a Z-scheme MOC/COF piezo-photocatalytic system, which provides an efficient way to use mechanical and solar energy to produce H-2 and H2O2 through overall water splitting.

Fluorescent photonic crystals (FPCs) are ideal candidates for regulating dyes' fluorescence through their unique photonic band gaps (PBGs). However, challenges, including the lack of dynamic regulation of fluorescence, dye release in solvents, and instability, dramatically limit their practical applications. Here, we report mechanochromic and solvomechanochromic rhodamine B (RhB)-based FPCs with dynamic regulation of photoluminescence (PL) by stretching and swelling, brilliant fluorescent and structural colors, and no release of the RhB in solvents. The FPCs with force/solvent-responsive nonclose-packing structures were fabricated by (1) preparing RhB-silica particles by combining click chemistry and cohydrolysis processes and (2) self-assembling these particles in poly(ethylene glycol) phenyl ether acrylate followed by a photopolymerization. Maximal PL inhibition (37%, stretching strain of 6.8%) and enhancement (150%, swelling time of 8 min) were gained when PBGs and their blue edges are precisely adjusted to the PL peak position, respectively. Compared with stretching, PL regulation is more efficient by swelling. These characteristics benefit from the rational design and combination of unique compositions, chemical bonds, nonclosely packed micro/nanostructures, and solvents for swelling. Moreover, these FPCs have been used to encrypt photonic patterns, which display background/strain/angle/UV-dependent color contrasts, showing their potential applications in multilevel anticounterfeiting, optical devices, wireless sensors, etc.

Printable colloidal photonic crystals (CPCs) with unique photonic bandgaps and elaborate shapes have attracted significant interest due to their characteristics, such as simplicity of fabrication, adjustable structural colors, photobleaching resistance, and stimulus‐responsiveness. In this review, strategies for printing CPC patterns, including direct use of CPCs as inks, region‐selective modification on responsive (solvent, force, and temperature) CPC papers, and printing combined with lithography, are first summarized. Second, based on the advantages of CPC printing technology, their applications in color displays, coatings, sensors, anticounterfeiting labels, and information storage, are discussed in detail. Finally, the current challenges and outlook regarding CPC printing technology are proposed.