Directed energy deposition (DED) has emerged as an attractive manufacturing and remanufacturing technology for high-performance martensitic stainless steels owing to its flexibility and high material utilization. The rapid solidification and cyclic thermal history inherent to the DED process generate a supersaturated martensitic microstructure, giving rise to precipitation behaviors that differ from those of conventionally processed materials. Therefore, elucidating the relationship between precipitation evolution, microstructural development and mechanical performance is essential for understanding the aging response and precipitation behavior of DED-fabricated martensitic stainless steels. In this work, XM-25 steel was fabricated by DED and subsequently aged at 460 °C for 10 h. Multi-scale characterization, integrating OM, SEM, EDS, XRD, TEM, SAED, FFT, and EBSD with tensile and microhardness measurements, was employed to systematically elucidate the precipitation behavior, microstructural evolution, and strengthening mechanism.The DED-fabricated XM-25 deposit exhibited excellent metallurgical bonding and a refined lath martensitic microstructure without detectable macroscopic defects. Aging at 460 °C for 10 h promoted a cooperative multi-phase precipitation process involving (Ni,Cr)2Nb-type Laves phase, NbN-type MX phase, Cr-rich M23C6 carbides and Cu-rich clusters. TEM observations demonstrated that these strengthening phases were dispersed within the martensitic matrix, while EBSD analysis revealed that the measured reduction in ECD after aging was mainly associated with enhanced crystallographic subdivision of the martensitic substructure, together with the retention of a high dislocation density and a stable martensitic substructure after aging. Consequently, the ultimate tensile strength and 0.2% yield strength increased from 1129.6 ± 17.5 MPa and 959.3 ± 36.5 MPa in the as-built condition to 1315.0 ± 8.7 MPa and 1207.7 ± 15.5 MPa, respectively, after aging at 460 °C for 10 h, accompanied by an increase in the deposited-layer hardness from approximately 360-370 HV to 390-410 HV, while the fracture mode remained dominated by ductile microvoid coalescence.The combined microstructural and mechanical results reveal that the enhanced mechanical performance originates from the synergistic interaction between rapid-solidification-induced supersaturation, cooperative multi-phase precipitation and precipitation-dislocation interaction. This work establishes a direct processing-precipitation-microstructure-property relationship for DED-fabricated XM-25 steel, providing new insight into the precipitation behavior and strengthening mechanisms of additively manufactured Cu-bearing martensitic stainless steels.
Objectives Tetrahedral framework nucleic acids (tFNAs) are DNA nanomaterials characterized by a three-dimensional tetrahedral structure. Owing to their excellent programmability, structural stability, biocompatibility and efficient cellular uptake, tFNAs have emerged as promising platforms in the biomedical field. This review aims to systematically summarise the core biological advantages of tFNAs and their latest research progress in the treatment of multi-system diseases, thereby providing a reference for further investigation and clinical translation. Methods We comprehensively reviewed recent literature on tFNAs, focusing on their intrinsic biological activities and their applications either as standalone therapeutic agents or as drug delivery carriers. Particular attention was paid to studies involving the skeletal, joint, spinal, nervous and muscular systems. Results tFNAs exert direct regulatory effects on cell proliferation, migration and differentiation, and possess intrinsic capabilities for scavenging reactive oxygen species and suppressing inflammatory responses. As therapeutic agents or nanocarriers, tFNAs have shown promising efficacy in a range of conditions, including avascular necrosis of the femoral head, bone defects, osteoarthritis, intervertebral disc degeneration, nerve injury and sarcopenia. The functionalisation of tFNAs with aptamers, drugs or signaling molecules further enhances their targeting specificity and therapeutic potency. Conclusions The unique structural and biological properties of tFNAs position them as versatile tools for treating diseases across multiple systems. Future efforts should focus on optimising drug-loading strategies, elucidating long-term biosafety profiles, and advancing well-designed preclinical and clinical studies to accelerate the translational application of tFNAs.
Enzymes overexpressed in the tumor microenvironment (TME), such as matrix metalloproteinases, cathepsin B, and legumain, serve as well-established endogenous triggers for tumor-selective drug delivery and imaging. Despite extensive preclinical progress, translating enzyme-responsive drug delivery nanosystems into clinical oncology has proven difficult, owing to incomplete understanding of enzyme heterogeneity across patient populations, a lack of standardized design principles, and a persistent gap between animal-model performance and clinical outcomes. This review organizes nine TME-overexpressed enzymes by their catalytic mechanisms and examines four design strategies: enzyme-sensitive drug release, shielding protection, carrier deformation, and imaging-switch activation. We then consider how tumor-intrinsic factors shape nanosystem behavior in vivo, including pH gradients, redox conditions, extracellular matrix density, interstitial fluid pressure, and molecular heterogeneity. For the major enzyme targets (MMP-2/9, cathepsin B, legumain, esterases, and oxidoreductases including TrxR, NQO1, and nitroreductase), representative delivery platforms are surveyed together with their therapeutic and diagnostic performance across optical imaging, MRI, photoacoustic imaging, Raman imaging, and multimodal approaches. Building on this evidence, the review identifies four translational barriers: inter-patient enzyme variability, off-target activation, protein corona interference, acquired resistance and Preclinical models. It also discusses emerging strategies that may help bridge the gap between laboratory innovation and bedside application, including patient-specific enzyme profiling, multi-stimulus safety-check architectures, and clinically relevant preclinical models.
Material selection and manufacturing route jointly influence fabrication scalability, assay implementation, and pharmacological performance in organ-on-a-chip systems. Although polydimethylsiloxane (PDMS) remains widely used in academic research, its multistep manual fabrication and absorption of hydrophobic compounds present challenges for scalable and quantitative drug evaluation. Here, we present a staged manufacturing translation framework connecting conventional PDMS fabrication, direct biological prototyping in biocompatible DLP resin, and scalable production using injection molded polystyrene (PS). An open, rail guided architecture enabled capillary hydrogel compartmentalization in the resin and PS devices, supporting vascularized MPS implementation across successive manufacturing approaches. Vasculogenesis, directional angiogenic sprouting, vascular tracer distribution, microbead transport, junctional marker expression, and cell viability were evaluated across the platforms. Concentration dependent responses to paclitaxel and 5 fluorouracil were also observed, with platform dependent differences in response magnitude and technical variability under the conditions examined. These findings are interpreted as platform level outcomes rather than isolated material effects because device architecture and assembly configuration differ across the original platforms. Overall, this study establishes an integrated engineering pathway from laboratory scale PDMS fabrication through resin based biological validation to scalable thermoplastic manufacturing, providing practical guidance for translating vascularized organ-on-a-chip systems toward scalable and standardized formats for drug evaluation.
This research presents a highly sensitive graphene-based surface plasmon resonance biosensor designed for efficient detection of breast cancer. An E-shaped graphene resonator integrated with a multilayer substrate is proposed to achieve strong light–matter interaction and effective detection. The sensor performance is systematically optimized by analyzing the effects of key geometrical parameters, including resonator length, width, height, substrate thickness, and angle of incidence. The results clearly give the highest sensitivity of 1430 nm/RIU for detecting breast cancer cells. The device exhibits strong sensitivity, enabling clear discrimination between normal and malignant tissue conditions. The highest value of 20.8 for the quality factor, and 11.9 RIU−1 for the figure of merit has been obtained. The high detection limit of 0.087 has been noted. Electrical tunability is further investigated through graphene chemical potential variation, revealing robust and stable optical response under different biasing conditions. Electric field distribution analysis confirms intense field localization at the resonator edges, which enhances sensing capability. Owing to its high sensitivity, compact geometry, and fabrication tolerance, the proposed graphene biosensor offers a promising platform for noninvasive, reliable, and early-stage breast cancer detection and other biomedical sensing applications.
Bone morphogenetic protein-2 (BMP-2) remains a cornerstone osteoinductive agent, yet its clinical translation is critically hampered by a material-driven delivery crisis necessitating supraphysiological doses that trigger severe complications. Reframing these challenges as a multifaceted material-design problem, this review proposes a transformative roadmap through synergistic strategies. Molecular engineering enhances intrinsic efficacy via BMP family alternatives, engineered BMP-2 variants, and biomimetic peptides. Additionally, it explores the enhancement of BMP-2 endogenous antagonist blockade, synergistic integration with bioactive agents, immunomodulation, and microenvironment simulation. Programmed spatiotemporal control enables material-engineered BMP-2 delivery through embedded/particulate carriers, porous scaffolds, surface immobilization, and engineered gene platforms. Smart-responsive systems enable adaptive dosing via stimuli-sensitive platforms. Collaborative microenvironment engineering orchestrates electrically amplified BMP-2 therapy, metabolic cues, and antibody-mediated osseous regeneration (AMOR), thereby amplifying endogenous signaling pathways to enhance bone regeneration. Collectively, we emphasize how rational biomaterial design—from nano-scale molecular tuning to macro-scale intelligent ecosystems—can fundamentally reprogram BMP-2's therapeutic window. This paradigm shift, from passive carriers to instructive, multifunctional platforms, charts a definitive course toward safer, more efficacious, and personalized next-generation bone regeneration therapies, underscoring the pivotal role of materials science in solving long-standing translational roadblocks.
The new graphene-based multilayered absorber design investigation for the ultrawideband spectrum, with an overall range of 2800 nm, is the focus of the current research. The multilayer is composited with the zirconium–titanium carbide–boron nitride (Zr–TiC–BN) over the graphene part, as the resonator design is mainly derived from the two squares. A two-square- and quadrant-shaped graphene solar absorber (SQGSA) has been developed in this study, achieving an overall efficiency of 94%. Near-perfect absorption (99.18%) is achieved at 500 nm and above 97% (97.16%) at 1200 nm, respectively. Machine learning for the Random Forest (RF) method and an R2 value above 0.99 can be optimized with a 0.25 test value. Polarization—an insensitive show for a 0–80 incidence angle in the current absorber and then the distribution of electric and magnetic fields involved with the wavelengths (μm) of 0.32, 0.45, 1.06, and 1.73, respectively. Design development with the lithography distribution, the structural optimization, and the resonator design derivation is also presented. With the main idea of using the thermal conversion, the developed absorber can be modified for solar dryer mining application.
Glass transition temperature (Tg) is a critical design parameter for heat-responsive 4D printed shape memory polymers because it defines the programming and recovery temperature window. However, Tg in vat photopolymerization printed polymers is controlled by multiple composition and post-curing variables, making exhaustive testing across all possible parameter combinations inefficient and difficult to interpret. A Graeco-Latin square design was used to arrange four parameters, photoinitiator concentration, crosslinker to monomer ratio, post-curing time, and post-curing temperature, at five levels with balanced parameter combinations. Factor contribution analysis showed that post-curing temperature had the largest main effect share at 48.85%, followed by the crosslinker to monomer ratio with 32.83%. In addition, the dataset was used to fit support vector regression (SVR) as the primary predictive model, while linear regression, quadratic response surface model, and Gaussian process regression were included for performance benchmarking. When evaluated using an independent one factor at a time dataset, SVR showed the lowest prediction errors, with an external validation mean absolute error of 1.13 °C, root mean square error of 1.48 °C, and R2 of 0.89. The SVR model was used to construct multivariable Tg response maps and model-derived Tg envelopes across the investigated design space. These results demonstrate that a limited and systematically designed experimental dataset can be used for factor contribution analysis, multivariable response mapping and Tg prediction in heat-responsive 4D printed polymers.
Bone-tendon interface (BTI) injuries remain a major clinical challenge because current fixation materials often fail to achieve synchronized mechanical support and biological regeneration, resulting in fibrovascular scar formation and high rerupture rates. Biodegradable magnesium (Mg) alloys have emerged as promising candidates for BTI repair owing to their bone-matched elastic modulus, favorable biodegradability, and the multifunctional biological activities of released magnesium ions. In this review, we systematically summarize the stage-specific healing process of the BTI and integrate current evidence regarding the biological functions of Mg ions throughout inflammation, repair, and remodeling. We highlight how Mg ions regulate macrophage polarization, promote osteogenesis, angiogenesis, fibrocartilage regeneration, and biomechanical adaptation through coordinated modulation of multiple signaling pathways. We further discuss the major barriers limiting clinical translation, including rapid degradation, insufficient mechanical durability, uncontrolled corrosion, and degradation-associated microenvironmental changes. Recent advances in alloying strategies, surface engineering, and intelligent self-healing coatings are comprehensively evaluated, with particular emphasis on their synergistic roles in balancing mechanical stability, corrosion resistance, and biological functionality. Rather than considering alloy composition and coating design as independent optimization approaches, this review proposes a stage-oriented design framework in which degradation behavior, ion release, and interfacial bioactivity are coordinated with the dynamic healing requirements of the BTI. This comprehensive strategy offers new insights into the rational design of next-generation biodegradable magnesium implants, aiming to provide a framework for achieving programmable degradation, precise tissue regeneration, and successful clinical translation in BTI repair, while also offering new perspectives for future researchers.
Giant core/shell quantum dots (GQDs) offer advantages for optoelectronics, including suppressed blinking and reduced Auger recombination, yet thick-shell growth often requires laborious successive ion layer adsorption and reaction (SILAR) cycles. Here we demonstrate a chlorine-mediated controlled Ostwald ripening strategy that transforms NIR-emitting CdHgSe/CdS core/shell seed QDs into giant CdHgSe/CdHgSeS core/gradient-shell QDs in a single post-synthetic step. Seed QDs are prepared by growing a thin (∼1.6-monolayer) CdS shell on CdHgSe alloy cores. Injection of CHCl3 at 240 °C triggers rapid ripening, in which most seeds dissolve while a minor population grows into GQDs. During ripening, the band-edge absorption feature is strongly attenuated and absorption below ∼610 nm increases markedly, whereas NIR emission remains centered near ∼900 nm, yielding a large effective Stokes shift that can mitigate reabsorption in luminescent solar concentrators. HAADF-STEM/EDS and XRD support a compositionally graded shell, while mass spectrometry and numerical simulations are consistent with chlorine-modified surface chemistry and altered monomer solubility/surface tension that accelerate ripening. As a proof of concept, embedding the GQDs in PMMA affords a transparent luminescent solar concentrator prototype with retained NIR emission and favorable spectral overlap with silicon photovoltaics.
Objectives DNA is increasingly utilized as a functional material beyond its canonical role as a genetic carrier. Owing to its exceptional structural predictability, physicochemical robustness, and high information density, DNA has found expanding applications in synthetic biology, biosensing, materials engineering, and digital data storage. These applications impose stringent requirements on DNA structural integrity and stability under extracellular conditions. However, intrinsic instability and environmental stresses remain major challenges. Although cryogenic storage is effective, achieving reliable preservation under ambient conditions would greatly facilitate the scalability and practical deployment of DNA-based technologies. Methods This review systematically examines the chemical and physical processes underlying DNA instability and discusses how environmental factors, including temperature, humidity, reactive oxygen species, and ultraviolet radiation, govern degradation kinetics. We further summarize analytical approaches for assessing DNA stability across chemical, conformational, structural, and functional dimensions, and review representative preservation strategies in both solid-state and liquid systems. Results Current preservation strategies mitigate DNA degradation through distinct mechanisms and exhibit considerable differences in preservation performance, accessibility, and application suitability. No universal preservation strategy can simultaneously satisfy the diverse requirements of all DNA applications. Instead, preservation performance depends on balancing long-term stability with practical accessibility according to application-specific priorities and operational constraints. Conclusions An integrated understanding of DNA degradation mechanisms, multilevel stability assessment, and application-specific requirements provides a basis for the rational selection and optimization of DNA preservation strategies. Balancing preservation stability with practical accessibility according to application needs will be critical for developing reliable and scalable DNA preservation systems for non-cold-chain applications.
This study explored the solidification performance of high-moisture engineering waste mud treated by NSSF composite binders (N-NaOH, S-slag, and SF-silica fume). Solidified specimens were subjected to unconfined compressive strength, drying water loss and microstructural scanning tests. We assessed the joint effects of NaOH dosage, silica fume-to-slag ratio, and curing time, and interpreted the synergistic mechanism from microscopic observations. The results show that the strength of the solidified body rose initially and then dropped as NaOH content increased, while it changed nonlinearly with the SF/S ratio. Under low-alkali conditions (NaOH ≤5%), increasing NaOH first enhanced and then reduced strength; under high-alkali conditions (>5%), strength continued to decrease. When pH reached 12 ± 0.1 and stabilized, the reaction system approached a balanced state, which coincided with the optimum mix proportion in this study. Higher alkali content combined with higher silica fume content contributed to improved toughness and crack resistance. Microstructural evidence revealed that moderate silica fume filled internal pores and facilitated CSH gel formation. Excessive silica fume, in contrast, lowered strength but created a macroporous network that favoured water retention and crack suppression. Together, these results provide theoretical support for developing low-carbon, environmentally friendly NSSF binders and applying them to stabilize problematic soils, particularly high-moisture construction waste mud.
Additive manufacturing (AM) enables the fabrication of complex, customized structures with efficient material use. In parallel, the global imperative for sustainable materials has intensified interest in bio-based composite materials derived from renewable biological sources and often reinforced with natural fibers or fillers. This review critically examines the convergence of AM and bio-based composites, offering a comprehensive analysis of current advancements, technical challenges, and future directions. It explores the suitability of various AM techniques, such as material extrusion (ME), vat photopolymerization, powder-based methods, etc., for processing bio-based polymers including cellulose, lignin, chitosan (CS), polylactic acid (PLA), etc. Key challenges such as poor thermal stability, low crosslinking density, and printability limitations are discussed alongside emerging strategies for overcoming them, including chemical modification, hybrid composite design, and parameter optimization. The review further delves into the evolution of 4D printing with bio-based stimuli-responsive materials, enabling applications in soft robotics, smart packaging, regenerative medicine, etc. By synthesizing interdisciplinary advances from materials science, mechanical engineering, and environmental design, this article highlights both the promise and complexity of integrating sustainability and functionality in AM. The insights provided serve as a roadmap for developing high-performance, eco-conscious systems that align with global sustainability goals.
Repair of osteochondral defects remains a critical unmet clinical challenge in knee osteoarthritis management, with core bottlenecks of insufficient regenerative capacity at the cartilage-subchondral bone interface and the high propensity for hypertrophy and calcification of bone marrow mesenchymal stem cells (BMSCs) after chondrogenic differentiation. To address these hurdles, we developed a 3D-printed biphasic scaffold. The subchondral bone layer was a composite system of BMSC-laden hydrogel (composed of Alginate Methacryloyl, hyaluronic acid methacrylate (HAMA), polycaprolactone, and gelatin methacrylate (GelMA)) integrated with a polycaprolactone electrospun support skeleton, loaded with bone morphogenetic protein-2 (BMP-2) and vascular endothelial growth factor 165, to promote osteogenic differentiation of BMSCs. The cartilage layer was an induced pluripotent stem cell (iPSC)-laden hydrogel consisting of decellularized porcine knee cartilage extracellular matrix, HAMA, chondroitin sulfate methacrylate, and GelMA, loaded with BMP-2 and transforming growth factor-β3. This formulation induced chondrogenic differentiation of iPSCs while maintaining their chondrogenic phenotype and reducing hypertrophy/calcification-associated gene expression. Importantly, transcriptomic analysis suggested that PI3K/Akt pathway suppression was most evident during the middle-to-late stage of chondrogenic induction (14-21 d), a window that may be associated with maintenance of the iPSC chondrogenic phenotype and suppression of hypertrophy and calcification. The scaffold exhibited native tissue-matched biomechanical properties, excellent biocompatibility, and sustained growth factor release capacity. In a rabbit knee osteochondral defect model, the scaffold achieved substantial osteochondral tissue regeneration at 16 weeks post-implantation, providing a potential strategy for integrated osteochondral defect repair.
This work presents a strategy to control the dispersion and stratification degree of functional organic molecules, such as organic corrosion inhibitors, in polymeric matrices and studies its effect on their water-controlled release. 2,5-Dimercapto-1,3,4-thiadiazole (DMTD) was used as the model inhibitor and p (BMA-co-MMA) as the polymer matrix. By systematically varying solvent–inhibitor compatibility and inhibitor loading, films with distinct and previously unreported self-stratified architectures were obtained, exhibiting different degrees of inhibitor dispersion and aggregation. Poor DMTD solubility, as in toluene, produced stratified films, whereas better solvents such as tetrahydrofuran, methyl ethyl ketone, and methyl isobutyl ketone yielded dispersions governed by solubility and evaporation rate. Uniform dispersion, typically accompanied by larger Tg depression, generally correlated with faster initial release in salty water, though this effect could be offset by stronger inhibitor–matrix interactions. Aggregate- or layer-rich structures supported extended inhibitor release through gradual inhibitor dissolution in the DMTD-rich domains in the hydrophobic polymer matrix. Preliminary immersion tests on AA2024 demonstrate that DMTD released from the coatings remains corrosion-active, effectively suppressing localized corrosion following coating damage. Overall, the ability to tailor film structure through solvent selection and inhibitor concentration represents a powerful tool for embedding reactive molecules in polymer matrices for use in engineering coatings.
MXenes are an outstanding category of two-dimensional transition-metal nitrides, carbides and carbonitrides that have surfaced as interesting candidates for thermoelectric study due to their superior electrical conductivity, adjustable surface chemistry and layered structure. This review thoroughly analyzes the thermoelectric characteristics of MXene-based materials, starting with an overview of MXene chemistry and production and then providing an in-depth explanation of the fundamental mechanisms related to electrical and heat transport in these materials. To provide a consistent design framework, a methodical examination of techniques to improve thermoelectric performance such as interlayer spacing control, surface termination engineering, doping and energy filtering, intercalation, and defect/interface engineering is carried out in this article. The thermoelectric characteristics of composition-specific pristine and doped MXenes are then examined in the article, which also identifies important gaps in experimental data for additional MXene families and emphasizes the relative advantages of Mo-based devices. By combining polymers, inorganic phases and carbon-based materials, MXene-based composite thermoelectrics are investigated as a potential means of reducing intrinsic limitations through interfacial and hierarchical transport phenomena. The review describes the principal problems of stability, measurement repeatability, scalability and device integration while offering a balanced viewpoint on prospective research trajectories. This study characterizes MXenes not as independent high-efficiency thermoelectrics, but as adaptable and modifiable components for advanced thermoelectric systems.
With its significant impact on advancements in the medical field, the Surface Plasmon Resonance (SPR) technique has wide-ranging applications in biomolecular detection, including the identification of cancer cells, bacteria, viruses, and biomarkers in blood, urine, and serum samples. SPR biosensors can achieve high-sensitivity outputs and function as label-free photonic devices. The current SPR biosensor design for a diamond shape has been investigated with the novel metal combination of Au-Ag. Based on the SiO2 layer and graphene, the proposed design has been developed with a 714.28 nm/RIU sensitivity rate over 1560 – 1640 nm wavelength determination for two cancerous cell detections: blood and adrenal gland. Quality factors are 134.4 (blood) and 146.9 (adrenal gland) for cancerous cells with 0.011722 and 0.010514 detection limits, respectively. With the ML parametric (resonance and substrate) optimization, the R2 value is above 0.96, and the field intensities (electric and magnetic) have been displayed over all layers of the SPR biosensor design. The current novel metal graphene-based SPR biosensor design can be used for detecting cancerous cells.
Exosomes carry complex molecular cargo, including proteins, lipids, and RNAs, that reflects the physiological state of their parent cells. This property gives them considerable potential as circulating biomarkers and therapeutic delivery vehicles. However, their clinical translation remains limited by several practical challenges, including rapid clearance after administration, loss of stability during handling or delivery, and the technical difficulty of detecting low-abundance disease-associated exosomes in complex biofluids.This review focuses on two emerging three-dimensional strategies designed to address these challenges. First, we examine hydrogel-based exosome delivery. The three-dimensional networks of hydrogels can physically retain exosomes, protect them from degradation, and enable sustained local release over days or weeks. Advanced hydrogel formulations can also respond to local pathological cues, such as reduced pH or elevated reactive oxygen species, thereby providing spatiotemporal control over exosome release. We summarize how different loading strategies, including physical adsorption, covalent conjugation, and in situ gelation, have been applied in tissue regeneration, immunomodulation, and cancer therapy.Second, we discuss three-dimensional DNA nanotechnology for exosome detection. DNA nanostructures, including tetrahedra, nanocages, and origami architectures, can be precisely assembled through programmable base-pairing interactions. Their controllable geometry and surface chemistry enable specific exosome capture and signal amplification at the nanometer scale. By integrating aptamers or complementary probes with fluorescence or electrochemical readouts, these platforms can detect exosomal surface markers and internal RNAs with sensitivities higher than those achieved by many conventional methods.Finally, we briefly compare commonly used exosome isolation methods, including ultracentrifugation, immunoaffinity capture, and microfluidics, and discuss their respective limitations. The review concludes with a perspective on how smart materials and integrated material design may facilitate the translation of exosome-based diagnostics and therapeutics toward clinical application.
Skincare peptides exhibit diversified mechanisms with signaling peptides, carrier peptides, neurotransmitter-inhibitory peptides, and other specific mechanisms. The stability, activity, and applicability of the existing skincare peptides can be enhanced by altering their amino acid compositions, introducing cyclic structures, and/or making specific side chain modifications, to provide adequate peptide candidates for skincare product bio-designs and applications. Hence, this article focuses on advances and chances of developing different types of skincare peptides. After exploring the functional mechanism of skincare peptides as well as the optimization of their structure and delivery, a peptide pool framework is also proposed with Virtual (large-scale skincare-potential peptide sequences and structures for specific in silico screening), Testable (small-scale synthesized peptides for skincare tests), and Bio-designed (synthesized peptides for skincare bio-designs and applications) pools. This peptide pool framework is expected to simplify the processes of developing reliable skincare peptides from sequence-/structure-screening, experimental testing, structural improvement, individual bio-design, to industrial application processes. Subsequently, a SWOT (strengths, weaknesses, opportunities, and threats) analysis is conducted to discuss the current state and future prospects of industrial skincare peptides. Finally, the representative peptide-based skincare products and the related patents are summarized to highlight current applications and future opportunities. Despite recent advances, ongoing research is needed to explore the stability, compatibility, safety, efficacy, optimization, bio-design, and application of candidate skincare peptides, constantly driving the development of innovative peptide materials and peptide-skincare products.
Poly(3,4-ethylenedioxythiophene) (PEDOT) thin films are promising transparent conductors for electrodes and represent a potential alternative to indium tin oxide (ITO), which is costly and depends on critical raw materials. Optimizing PEDOT properties through careful control of processing parameters is essential for tailoring structure–property relationships in next-generation electronic devices. This study systematically investigates the influence of the oxidant-to-monomer ratio (OMR) on PEDOT films deposited by oxidative chemical vapor deposition (oCVD). The monomer 3,4-ethylenedioxythiophene (EDOT) and the oxidant antimony pentachloride (SbCl5) were used. By varying only the SbCl5/EDOT vapor-phase ratio while keeping the deposition temperature (150 °C) and film thickness (∼100 nm) constant, the effect of OMR on film morphology, molecular structure, and electrical properties was isolated. Films deposited at lower OMR values (0.1) exhibited higher electrical conductivity, attributed to reduced structural disorder. These effects were further confirmed in diode devices fabricated on both rigid and flexible substrates. PEDOT films deposited at an OMR of 0.1 produced bottom electrodes with superior electrical performance, demonstrated by higher current density and improved rectification ratio. The PEDOT films were also integrated into printed flexible zinc oxide (ZnO) Schottky diodes, achieving good rectification ratios and favorable ideality factors. Overall, the results demonstrate that the oxidant-to-monomer ratio is a critical parameter for tuning PEDOT film properties. This approach enables the fabrication of PEDOT electrodes with application-specific electronic characteristics, supporting their use as potential ITO alternatives while facilitating scalable vapor-phase processing for flexible electronic devices.
