Search Results (968)

Melanin-like polymers, particularly polydopamine, have gained significant attention as photothermal materials due to their broad light absorption (ultraviolet to near-infrared), high photothermal conversion efficiency, negligible fluorescence, good biocompatibility regarding unmodified melanin-like polymers, and universal adhesion. Upon light irradiation, these bioinspired polymers convert absorbed optical energy into heat through molecular vibration and electron–phonon coupling, making them ideal for diverse photothermal applications. This review comprehensively summarizes recent advances in using melanin-like polymers for photothermal purposes. In biomedical engineering, they serve as efficient agents for photothermal therapy and synergistic antibacterial treatment. In catalysis, their photothermal effect enhances pollutant degradation, hydrogen production, and chemical warfare agent detoxification. For water remediation, melanin-like polymers are fabricated into evaporators, membranes, and aerogels for solar-driven steam generation, desalination, and oil spill cleanup. They also enable sensitive photothermal sensing, near-infrared imaging, and laser desorption ionization mass spectrometry imaging. Furthermore, these materials are incorporated into soft actuators and self-healing elastomers for light-controlled shape memory, programmable folding, and remote manipulation. Finally, we discuss remaining challenges such as long-term stability, biocompatibility, scalability, and color limitations and provide future perspectives for advancing melanin-like photothermal materials toward practical applications. Full article

Silk fibroin (SF)–polyphenol systems have emerged as a versatile class of gels and hydrogels in which supramolecular interactions and dynamic crosslinking regulate network formation, responsiveness, and multifunctional performance. Polyphenols interact with SF through hydrogen bonding, hydrophobic interactions, π–π stacking, metal coordination, and covalent crosslinking, thereby modulating conformational transitions, gelation behavior, structural stability, and interfacial functionality. These interaction mechanisms enable the development of SF–polyphenol gel systems with tunable mechanical properties, wet adhesion, antioxidant activity, self-healing capability, and stimuli responsiveness. This review summarizes recent advances in SF–polyphenol gels and hydrogels, with particular emphasis on molecular interaction mechanisms, gelation and fabrication strategies, responsive behaviors, and structure–property relationships. Representative preparation approaches, including solution blending, electrospinning, impregnation–adsorption, enzymatic crosslinking, metal–phenolic coordination, and photo-initiated processing, are systematically discussed in relation to their effects on network architecture and functional output. The responsive behaviors of these systems under pH, redox, electrical, thermal, and optical stimuli are also analyzed from the perspective of dynamic gel networks and adaptive material design. Emerging applications of SF–polyphenol gels in bioadhesives, delivery platforms, flexible bioelectronics, wound-related materials, and sustainable functional systems are highlighted. Current limitations associated with polyphenol instability, formulation sensitivity, reproducibility, and scale-up are critically discussed, together with future opportunities for predictive design of gel-based natural polymer systems. This review provides a comprehensive framework for understanding SF–polyphenol gelation and for guiding the development of next-generation multifunctional gels and hydrogels. Full article

Abusive relationships are too often explained solely in terms of individual behaviour, as if a woman’s decision to stay were simply a matter of psychology or poor judgement. In South African communities, however, the reality is considerably more complex. The reasons women remain are situated within what can be described as a distorted process of care: a network of relational, material, and structural forces that alter the very meaning of care itself. This study aimed to explore these interconnections. Guided by an ethics of care framework, we employed multimodal qualitative methods to engage participants from four South African communities between August 2024 and July 2025. Participants (n = 262) were recruited through snowball, purposive, and convenience sampling. Data were coded using ATLAS.ti V8 and analysed thematically. Five interconnected themes shaped the framework. Distorted care described how caregiving could become coercive, shaped by fear, rigid gender roles, intergenerational abuse, and substance misuse. Care under constraint highlighted the material limitations, financial dependency, daily survival challenges, and self-sacrificing caregiving, that left women depleted. The silence of care captured emotional withdrawal, isolation, and the disabling effect of shame on help-seeking. Reclaiming care traced the tentative routes towards healing through ethical self-care, faith, forgiveness, and a conscious effort to disrupt harmful patterns. Woven throughout was structural failure, including absent family networks, the moral decline of communities, and institutional systems that consistently failed women. Remaining in an abusive relationship is not a sign of weakness. It is a negotiation, profoundly constrained, within systems of care that have been fundamentally distorted. Effective intervention should move beyond framing gender-based violence as an individual problem and address it as a collective one, restoring care as a shared social and political responsibility. Full article

The emergence of multifunctional wound dressings represents a significant transformation in the care of cutaneous tissue injuries, providing advanced solutions that surpass traditional dressings. This study is poised to fabricate multifunctional hydrogels through dual-dynamic cross-linking, integrating antibacterial and antioxidant properties, which are capable of accelerating wound healing while improving therapeutic outcomes. The hydrogel, which exhibits excellent adhesion, rapid self-healing ability, and on-demand removability, was synthesized employing poly(vinyl alcohol) (PVA)–borax as the backbone, followed by the incorporation of silk fibroin (SF), tannic acid (TA), and chitosan (CS). Total saponins of Panax notoginseng flower buds (PNF) with anti-inflammatory and angiogenic properties were loaded in porous structural materials yielding the PBCTS@PNF hydrogel. The prepared hydrogel exhibited outstanding antioxidant properties and cytocompatibility, along with favorable antibacterial capabilities, achieving inhibition rates of 84.30 ± 2.34% against Escherichia coli (E. coli) and 98.12 ± 0.76% against Staphylococcus aureus (S. aureus), respectively. Animal experiments demonstrated that PBCTS@PNF significantly reduced inflammation and promoted multidimensional tissue regeneration, encompassing re-epithelialization, neovascularization, and hair follicle regeneration, along with ordered collagen matrix organization, leading to substantially accelerated wound healing. The multifunctional PBCTS@PNF hydrogel provides a potent bioengineered therapeutic platform for wound healing management through the synergistic interplay among antibacterial, anti-inflammatory, and tissue regenerative functionalities. Full article

Micro- and nano-container-based self-healing coatings have emerged as a promising strategy for the long-term conservation of cultural heritage artifacts, including metals, stone, organic matter, and construction materials. These coatings incorporate microcapsules or nanocapsules with tailored shell and core materials, enabling autonomous release of healing agents or corrosion inhibitors in response to damage. For metallic artifacts, benzotriazole@mesoporous silica nanoparticles (BTA@MSN) microcapsules achieve selective pH-responsive release, reaching 77% at pH 9.0 and 42% at pH 5.0, effectively mitigating localized corrosion. Temperature-adaptive poly(methyl methacrylate-co-methacrylic acid) (PMMA-MA)/MgO microcapsules exhibit controlled rupture rates, with a 75% reduction at elevated temperatures, enhancing crack repair efficiency by approximately 5%. Organic artifacts, such as wooden or paper manuscripts, benefit from clove oil nanocapsules, which increase tensile strength by 43.5% and fracture toughness by 101.9%, with only 2.91% weight loss over 7 days compared to 33.1% for unencapsulated oil. Advanced fabrication methods—including microfluidics, Pickering emulsions, and multi-core systems—enable high encapsulation efficiency (up to 73.5%), uniform particle size, and repeatable healing. Multi-stimuli responsiveness (pH, temperature, light, magnetic fields) and biobased, environmentally friendly materials further enhance adaptability and sustainability. In this review, “self-healing” is defined broadly to include both physical crack repair and autonomous restoration of protective functions. Overall, self-healing micro/nanocapsule coatings provide a highly controllable, efficient, and durable solution for active heritage protection, representing a shift from passive to intelligent conservation strategies. Furthermore, a systematic comparison of different capsule systems is provided to clarify their respective advantages and limitations. Overall, hybrid systems exhibit the most balanced performance, while inorganic nanocontainers offer superior stability and controlled release, and polymeric capsules enable rapid healing but limited reusability. Full article

Metallic cultural heritage artifacts are highly susceptible to multi-factor electrochemical degradation, driven by chloride ions, humidity, acidic deposition, and heterogeneous material interfaces. Traditional conservation materials, including organic and inorganic coatings and corrosion inhibitors, often exhibit limited interfacial compatibility, poor long-term stability, and insufficient multifunctionality. Recent advances in protective materials—including nano-enhanced coatings, self-healing systems, smart-responsive polymers, green biodegradable formulations, and metal–organic framework (MOF)-based composites—offer multifunctional, long-lasting, and minimally invasive solutions. These materials enhance corrosion inhibition, barrier performance, structural reinforcement, and environmental responsiveness, while enabling in situ sensing, reversible application, and ethical deployment. Laboratory evaluation, accelerated aging tests, and field verification demonstrate their efficacy in preserving artifact integrity and aesthetics. This review systematically discusses degradation mechanisms, limitations of traditional materials, and the mechanisms, applications, and future perspectives of novel functional coatings, providing a roadmap for scientifically optimized and ethically responsible conservation of metallic heritage. Full article

This study demonstrates a molecular size-dependent strategy to regulate the network structure of poly(vinyl alcohol) (PVA) hydrogels using a series of saccharides with increasing molecular size—glucose, maltose, raffinose, soluble starch, and amylose. FTIR, XPS, XRD, and TG analyses reveal that increasing saccharide size shifts the network from plasticization to reinforcement, which is further confirmed by mechanical testing and rheological analysis. Small-molecule saccharides disrupt hydrogen bonds and enhance chain mobility, while macromolecular starches promote network regularity through strong hydrogen bonding and crystallization induction. This structural tunability ndows the resulting hydrogels with integrated functionalities: tensile strain increases from 640% to 1500%, self-healing efficiency reaches up to 90.6%, and high-fidelity electrocardiogram (ECG) signal acquisition is achieved with a signal-to-noise ratio of 39.84 dB, comparing favorably with commercial electrodes. This work establishes a structure–property relationship linking saccharide molecular size to network architecture and provides a versatile material platform for next-generation flexible wearable sensors and bioelectrodes. Full article

This paper provides a comprehensive review on the effects of plant fibers on cement-based materials, focusing on the enhancement of mechanical properties and durability. Plant fibers, as a sustainable and renewable resource, are increasingly recognized for their potential in improving the performance of cement-based composites. The review begins with an exploration of fiber composition and structure, followed by a detailed discussion of interfacial modification strategies that enhance the bond between plant fibers and cement matrices. Key mechanisms such as fiber dispersion, bridging, and internal curing are examined to explain how plant fibers impact hydration, pore structure, and mechanical properties like compressive strength, flexural strength, splitting tensile strength, and impact toughness. The paper also reviews the role of plant fibers in enhancing the durability of cement-based materials, particularly in terms of resistance to alkali degradation, acid attack, freeze–thaw cycles, chloride ion penetration, and self-healing behavior. The findings suggest that plant fibers offer a dual benefit by improving both the mechanical and durability performance of cement-based materials. The paper concludes with recommendations for future research directions, emphasizing the need for better understanding the interactions between plant fibers and cement matrices to optimize the long-term performance of plant fiber-reinforced cementitious composites. Full article

Self-healing materials (SHMs) are a class of bio-inspired materials capable of autonomously repairing damage, similar to how living organisms heal wounds. The core motivation behind SHMs is to extend the service life of components while enhancing safety and reducing maintenance or replacement needs. SHMs can be broadly categorized into intrinsic systems, which rely on reversible internal bonds (dynamic covalent or supramolecular interactions) to heal repeatedly, and extrinsic systems, which embed external healing agents (e.g., microcapsules or vascular networks) that are released upon damage to effect repairs. Researchers have demonstrated self-healing behavior in diverse material families, including polymers, metals, ceramics/cementitious materials, and protective coatings, thereby improving crack resistance, fatigue life, and reliability across aerospace, automotive, civil infrastructure, energy storage, and microelectronics applications. Advances in material design and additive manufacturing have started integrating SHMs into practical structures. However, challenges such as scaling up production, maintaining mechanical performance, and ensuring long-term durability remain. Reported healing efficiencies in self-healing materials typically range from ~50% to near-complete recovery (~100%), depending on material systems and testing conditions, highlighting key trade-offs between healing performance, mechanical integrity, and scalability. Overall, SHMs represent a promising strategy for creating safer and more sustainable engineering systems, with ongoing developments aimed at overcoming current limitations and expanding their capabilities. This review highlights key trade-offs between healing efficiency, mechanical performance, and scalability, providing insights into the design and application of next-generation self-healing materials. Full article

Urushiol, the key component of natural lacquer, is emerging as a versatile bio-based phenolic platform for advanced polymer systems. Its unique catechol structure, combined with an unsaturated aliphatic side chain, provides multiple reactive sites, enabling diverse chemical pathways and tunable network architectures. This review presents a systematic analysis of urushiol-based materials within a “structure–reaction–property–application” framework. The intrinsic reactivity of urushiol, including oxidative polymerization, dynamic covalent bonding, and metal–phenolic coordination, is correlated with the formation of crosslinked networks exhibiting controllable mechanical properties, strong interfacial adhesion, and stimuli responsiveness. Recent advances in functional coatings, self-healing and reversible polymers, bioactive materials, and cultural heritage conservation are highlighted. Special emphasis is placed on dynamic network design and low-sensitization strategies to overcome limitations of traditional lacquer systems. Finally, key challenges and future directions toward controllable curing, structure–property relationships, and sustainable material design are discussed, positioning urushiol as a bridge between traditional materials and next-generation functional polymers. Full article

Diabetic chronic wounds (particularly diabetic foot ulcers) are difficult to heal due to factors such as high glucose levels, infection, and inflammatory imbalance. In severe cases, they can lead to tissue necrosis and amputation. Hydrogel materials, as moist wound dressings, possess high water content, biocompatibility, and tunability, making them an important platform for promoting diabetic wound healing. In recent years, novel smart hydrogels have been developed to integrate multiple functions. They respond to abnormal stimuli in the wound microenvironment—such as acidic pH, high glucose levels, or excessive reactive oxygen species—to trigger the release of drugs, delivering on-demand antimicrobial, antioxidant, and anti-inflammatory effects. Simultaneously, they modulate immune responses (promoting macrophage polarization toward the M2 type) and stimulate angiogenesis, creating a microenvironment conducive to tissue regeneration. Some hydrogels incorporate antimicrobial agents, anti-biofilm components, or photothermal/photodynamic agents to effectively eliminate drug-resistant pathogens and control infections. Others serve as carriers for delivering stem cells and their exosomes, enhancing cell survival rates and releasing growth factors to accelerate wound healing. This review systematically summarizes recent advances in hydrogel strategies for diabetic wound treatment, focusing on stimulus-responsive hydrogels, antimicrobial and immune modulation mechanisms, pro-angiogenic and oxygen-supplying therapies, smart dressings and monitoring technologies, integration of stem cells and exosomes, as well as hydrogel injection, self-healing, and adhesion properties. Based on this, we analyze challenges and prospects for clinical translation of these strategies. Collectively, functionalized hydrogels hold promise as multifunctional therapeutic platforms for diabetic non-healing wounds. They offer a multi-pronged approach to disrupt the vicious cycle of “infection–inflammation–tissue destruction” thereby achieving more efficient wound healing. Full article

Nano-TiO₂ is widely used in many industrial fields due to its unique physical and chemical properties. In recent years, it has become a core material in the research of road engineering for degrading automobile exhaust. Under ultraviolet irradiation, it can excite electron-hole pairs and use its strong redox capacity to decompose automobile exhaust and improve air quality. From the perspectives of materials, performance and engineering application, this paper briefly describes the structure and physicochemical properties of nano-TiO₂, reviews the recent research progress of nano-TiO₂ in the photocatalytic degradation of automobile exhaust, systematically compares the effects of various strategies such as incorporation methods and modified materials on exhaust degradation efficiency, and conducts a quantitative analysis of performance differences. It is pointed out that insufficient road durability, poor compatibility with pavement materials and limited adaptability to unconventional environments are the main current problems and challenges in this research direction. The future development directions such as developing self-healing composite systems and constructing machine learning prediction models are also prospected. Full article

In recent years, bacteria-based self-healing has emerged as a promising bioengineering strategy to address the self-repair of cracks in cement-based materials, which represent one of the persistent durability challenges. This approach relies on microbiologically induced calcium carbonate (CaCO₃) precipitation (MICP), in which metabolically active bacteria promote CaCO₃ formation of crystals that can heal cracks and restore material integrity. This study compares the self-healing potential of a natural (N-) alkaline soil Bacillus licheniformis strain with a UV-strain (phenotypic mutant) generated through controlled UV exposure followed by adaptive evolution. Both strains were evaluated under conditions relevant to cementitious environments. The UV-strain exhibited enhanced ureolytic performance, reaching urease activity of 0.32 U/mg compared to 0.24 U/mg in the N-strain. This translated into improved biomineralization, with CaCO₃ precipitation reaching 2.37 mg versus 2.23 mg/100 mL in the N-strain. Additionally, the UV-strain showed increased cell hydrophobicity and aggregation, indicating improved nucleation potential and surface-mediated mineral deposition. Multivariate analysis confirmed strong correlations between ureolytic metabolism, alkalization, and mineral formation, while artificial neural network (ANN) modeling (MLP 6-10-14) successfully predicted biomineralization-related parameters with high accuracy (R² > 0.90 for urease activity, NH₄⁺, ΔpH, and CaCO₃). The results demonstrate that UV-induced phenotypic adaptation can enhance biomineralization efficiency with minor trade-offs in physiological robustness. For the first time, that controlled UV-induced phenotypic adaptation can be used as a targeted strategy to enhance biomineralization efficiency in B. licheniformis, while maintaining functional stability under cement-relevant conditions. These findings provide a novel framework for tailoring bacterial performance in self-healing systems for construction biotechnology. Full article

Road pavement rehabilitation increasingly incorporates innovative surface technologies aimed at improving pavement performance while reducing environmental impacts. In addition to conventional recycled asphalt pavement (RAP) maintenance strategies, advanced pavement surface systems such as reflective coatings, rejuvenator-based self-healing mixtures, and thin low-noise asphalt layers have been developed to enhance durability and functional performance. This study presents a comparative Life Cycle Assessment (LCA) of four pavement surface technologies using primary inventory data obtained from full-scale road sections. The systems evaluated include a conventional maintenance mixture and three alternative surface solutions: reflective pavement coatings, RAP mixtures incorporating rejuvenator-based self-healing systems, and thin low-noise asphalt layers. The assessment follows ISO 14040 and ISO 14044 standards and applies the ILCD 2011 midpoint+ (EF 2.0) method. To enable comparability between technologies with different durability, the functional unit was defined as 1 m² of rehabilitated pavement per year of service life. The results indicate that thin low-noise asphalt layers provide the highest environmental benefits across most impact categories due to significant material savings associated with reduced layer thickness. Reflective pavement coatings decrease several impacts, particularly fossil resource depletion and atmospheric emissions, although higher burdens are observed in some categories due to synthetic binder production. RAP mixtures incorporating rejuvenator-based self-healing systems improve resource efficiency and extend pavement durability but may increase impacts associated with binder manufacturing. Overall, the findings highlight relevant environmental trade-offs between different pavement surface technologies and demonstrate that parameters such as layer thickness, binder composition, recycled material content, and service life strongly influence environmental performance. The study illustrates how comparative Life Cycle Assessment supports the development and selection of more sustainable pavement surface systems. Full article

Bone tissue plays a vital role in the human body and possesses intrinsic self-repair mechanisms; however, large defects or pathological fractures may exceed its natural healing capacity. Bone tissue engineering provides promising strategies to restore bone integrity through the use of scaffolds, growth factors, and stem cells. While calcium phosphate (CaP)-based ceramics, such as hydroxyapatite (HAp) and tricalcium phosphate (TCP), represent the current benchmark, their limitations, including slow degradation (HAp) and limited osteoinductivity (TCP), have driven the development of alternative biomaterials. In this context, magnesium phosphate (MgP)-based materials have gained increasing attention due to their tunable resorption rate, improved biodegradability, and ability to stimulate osteogenesis and angiogenesis through the release of magnesium (Mg²⁺) ions. This study reports on composite scaffolds based on electrospun poly(ε-caprolactone) (PCL) fibres coated with MgP layers doped with lithium (Li) and zinc (Zn), designed to mimic the nanofibrous architecture of the extracellular matrix. Lithium and zinc were selected due to their known ability to modulate cellular response, with lithium promoting osteogenic activity and zinc contributing to improved cell proliferation and antibacterial potential. The phosphate phases obtained by coprecipitation were deposited onto the PCL fibres using Matrix-Assisted Pulsed Laser Evaporation (MAPLE), enabling controlled surface functionalization. Following thermal treatment, the formation of the crystalline magnesium pyrophosphate (Mg₂P₂O₇) phase was confirmed by chemical and structural characterization. The combination of a slowly degrading PCL matrix, providing sustained structural support, and a bioactive MgP coating, enabling rapid and controlled ion release, results in improved scaffold performance in terms of biocompatibility, biodegradability, and bioactivity. While the slow degradation rate of PCL ensures mechanical stability over an extended period, the surface-deposited MgP phase allows immediate interaction with the biological environment, facilitating faster ion release and enhancing cell–material interactions. These findings highlight the potential of the developed composites as promising candidates for trabecular bone regeneration and as viable alternatives to conventional CaP-based scaffolds in regenerative medicine. Full article