Polyethylene terephthalate (PET) undergoes thermo-oxidative and thermo-mechanical degradation during repeated mechanical recycling, resulting in a significant deterioration of material properties. In this study, PET vitrimers were prepared via reactive melt processing using a diepoxy crosslinking agent and a tertiary amine-containing polyol. To understand the fundamental characteristics of the prepared PET vitrimers, the rheological, mechanical, and thermal properties of vitrimers derived from virgin PET were first investigated. Frequency-sweep and stress-relaxation measurements showed that vitrimerization significantly increased the viscoelastic moduli and retarded terminal relaxation due to the formation of dynamic crosslinked network structures. Mechanical analysis revealed a trade-off relationship between tensile strength and elongation at break with increasing crosslinking density. Thermal analysis further demonstrated that denser crosslinked structures increasingly suppressed crystallization behavior. The effectiveness of vitrimerization for the upcycling of recycled PET was evaluated using PET samples with different recycling histories. Vitrimerization effectively restored the rheological and mechanical properties degraded by repeated recycling. Even after multiple recycling cycles, vitrimers prepared from recycled PET maintained properties comparable to those of vitrimers derived from virgin PET. These results demonstrate that reactive melt vitrimerization is a promising strategy for the high-value upcycling and sustainable recycling of PET. Reactive melt vitrimerization enables high-value upcycling of repeatedly recycled PET by recovering its rheological, mechanical, and thermal properties.
Messenger RNA (mRNA)-based therapeutics have emerged as a promising platform owing to their rapid development, design flexibility, and scalable manufacturing potential. However, the inherent instability of mRNA and the need for thermostable, high-capacity delivery systems remain major barriers to clinical translation. Herein, we report a high-dose coated microneedle (MN) platform based on contact dispensing coating (CDC), employing polyethyleneimine-coated silica nanoparticles (PSiNPs) as a high-capacity mRNA carrier to achieve nanoliter-level coating precision, accurate dose control, and enhanced mRNA stability. PSiNPs efficiently complexed with mRNA through electrostatic interactions, and an optimized PSiNP-to-mRNA ratio of 10:1 provided high encapsulation efficiency with low cytotoxicity and effective intracellular delivery. The CDC process enabled precise tip-selective coating, with the coating amount increasing linearly with the number of coating cycles. Among the evaluated coating formulations, polyvinylpyrrolidone-based formulations showed superior coating uniformity, dispersion stability, and intradermal delivery efficiency. Ex vivo and in vivo studies demonstrated efficient skin penetration, successful intradermal delivery of mRNA-loaded PSiNPs, and robust mCherry protein expression following MN application. This PSiNP-coated MN platform provides accurate dose control, improved formulation stability, and reduced dependence on cold-chain storage, offering a promising transdermal delivery strategy for next-generation mRNA vaccines and nucleic acid therapeutics.
Simultaneously enhancing the thermal stability, UV-shielding, and tensile properties of PLA-based composites is crucial for enabling their application in flexible UV-protective packaging. However, it remains a challenge to improve the mechanical performance while sustaining excellent thermal stability and UV-shielding due to a persistent issue in attaining non-uniform dispersion of filler within the polymer matrix. Unlike conventional low-filler loadings, this work investigates the effect of moderate loading (1–4wt
Three-dimensional (3D) curved micro- and nanostructure arrays are essential components for advanced optical, electronic, and biomimetic applications. Although Isolated Air-pocket Lithography (IAL) has emerged as a promising top-down approach to replicate curvilinear geometries, conventional IAL suffers from a critical resolution floor (typically 4 μm) due to the stochastic and rapid expansion kinetics of trapped air-pockets. In high-bubble-density environments, uncontrollable gas coalescence induces multi-axial structural distortion, limiting further miniaturization. To bypass this bottleneck, we propose an advanced IAL strategy that achieves sub-micrometer structural fidelity by precisely modulating the secondary micro-bubble density within a polydimethylsiloxane (PDMS) matrix via a controlled vacuum-degassing process. By systemically tuning the degassing duration, we decoupled the gaseous expansion velocity from the polymer cross-linking rate. This precise kinetic control enabled a highly predictable morphological evolution spanning asymmetric ellipses, symmetric spheres, hemispheres, and shallow circular segments. Notably, minimizing internal gas aggregation within confined spatial domains successfully pushed the replication limit down to the sub-micrometer regime, yielding uniform nanosphere arrays with a structural radius as small as 900 nm using a 500 nm master mold. Furthermore, secondary replica molding successfully transferred these highly uniform, flexible, and optically transparent convex architectures, demonstrating the industrial scalability of this maskless, cost-effective 3D nanofabrication platform.
Extracellular vesicles (EVs) have attracted considerable interest as next-generation drug delivery carriers owing to their intrinsic biocompatibility and capacity to transport bioactive cargos across biological barriers. Despite these merits, the effective therapeutic application of EVs requires efficient cargo loading while preserving vesicle integrity, which remains a fundamental challenge, particularly for active loading approaches. Electroporation is a promising method for loading nucleic acids and small-molecule drugs into EVs by transiently disrupting membrane permeability. However, electroporation is highly sensitive to experimental conditions, including both electrical parameters and the loading buffer medium. In most previous studies, commercial electroporation buffers or standard solutions such as phosphate-buffered saline (PBS) have been used, yet the influence of buffer composition on electroporation performance has not been fully elucidated. In this study, we systematically investigated how buffer physicochemical properties affect drug loading efficiency and identified an operational window that maximizes it while maintaining the structural integrity of EVs. Furthermore, Western blot analysis, nanoparticle tracking analysis, and transmission electron microscopy (TEM) confirmed the preservation of EV marker proteins, size distributions, and membrane morphology under the optimized buffer conditions. Collectively, this study demonstrates that understanding and tuning the key physicochemical properties of the buffer serves not merely as an auxiliary consideration but as a central design principle governing both loading efficiency and vesicle stability in electroporation-based EV drug loading. These findings provide fundamental guidance for the rational design of electroporation buffers, advancing the feasibility of EV-based therapeutic applications.
Poly(N-oxide) brushes, a novel class of zwitterionic polymers, were immobilized onto surfaces via “grafting from” approach. In contrast to betaine-based materials, N-oxide structures feature oppositely charged atoms in direct proximity without a carbon spacer, enabling enhanced hydration capacity and improved antifouling performance. In this study, a methacrylate-based N-oxide monomer (DMENOx) was synthesized and subsequently grafted onto silicon substrates via surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) under oxygen-tolerant conditions. The polymerization conditions were systematically investigated, resulting in the formation of uniform poly(N-oxide) brushes with a thickness of approximately 35 nm. The poly(N-oxide)-coated surfaces exhibited excellent antifouling properties, significantly repelling the adhesion of a diverse range of biofoulants, including proteins, bacteria, and marine diatoms. These findings demonstrate the potential of N-oxide-based polymer brushes as an effective antifouling platform for biomedical and marine applications.
Reactive flame-retardant polymer resins have emerged as a robust alternative to conventional additive-type systems, providing enhanced resistance to migration and improved compatibility within the polymer matrix. While the role of phosphorus oxidation states has been previously explored in core–shell particulate systems, the influence of oxidation state and substituent architecture within linear acrylic resins requires further investigation. This study focuses on the effects of phosphorus oxidation states and, more importantly, the structural differences between aliphatic and aromatic substituents in determining the fire performance of a series of phosphorus-containing linear acrylic resins. Three distinct phosphorus-based methacrylate monomers, DPMA (+ 1 oxidation state), DPOMA (+ 5 oxidation state, aromatic), and DEPMA (+ 5 oxidation state, aliphatic), were synthesized and incorporated into acrylic backbones via free-radical solution polymerization. The results demonstrate that at the same + 5 oxidation state, the substituent type plays a decisive role in determining condensed-phase efficiency. Specifically, the aliphatic system (PR-DEPMA) exhibited significantly enhanced charring capability compared to its aromatic counterpart (PR-DPOMA). At a 50 wt
Hydrogel microneedle patches offer minimally invasive access to interstitial fluid, yet on-patch immunoassays are often limited by surface-confined probe immobilization and multi-step conjugation workflows. Here, a PEGDA hydrogel microneedle platform is introduced that integrates fluid extraction and transfer-free immunoassays through linker-free antibody immobilization within a three-dimensional network. Antibodies are reduced with tris(2-carboxyethyl)phosphine to expose thiols, which undergo thiol–ene coupling with residual acrylates in the PEGDA matrix under mild aqueous conditions, enabling post-functionalization without additional linkers. The resulting patches insert reliably into ex vivo porcine skin and exhibit capillary-driven uptake with intramatrix access for protein-sized tracers in an agarose model, supporting intramatrix accessibility for protein-sized analytes within the microneedle interior. Using neutrophil gelatinase-associated lipocalin as a proof-of-concept target, the on-patch assay shows a concentration-dependent fluorescence response with a linear regime below 100 pg/mL and a limit of detection of 1.57 pg/mL. By performing capture and readout directly on the patch without sample transfer, the workflow shortens time-to-result to 2 h 40 min while retaining high analytical sensitivity. This platform provides a practical route to scalable, transfer-free microneedle immunoassays enabled by intramatrix analyte accessibility and three-dimensional probe presentation. Linker-free thiol–ene conjugation transforms PEGDA hydrogel microneedles into a three-dimensionalsensing matrix for fluid extraction and transfer-free on-patch immunoassays. The platform supportsdirect NGAL detection with high sensitivity, simplifying microneedle-based point-of-care diagnostics.
Poly(n-butyl cyanoacrylate) (PBCA) is a widely used adhesive; however, its long-term stability and unpredictable biodegradation behavior under physiological conditions remain concerns for applications requiring prolonged in-body exposure. To assess its stability and preliminary biosafety under simulated physiological conditions, this study employed a combined kinetic and biological approach to systematically investigate the degradation mechanism and predict the thermal-stability lifetime of modified PBCA adhesives. Thermogravimetric measurements performed at multiple heating rates yielded an average activation energy of 109.4 kJ/mol. The degradation followed a phase-boundary-controlled mechanism with cylindrical symmetry, consistent with the R2 model. Kinetic predictions revealed a strong temperature dependence, where the thermal-stability lifetime declined from over 473 days at 37 °C to approximately 85 days at 50 °C. Additionally, MTT assays, LIVE/DEAD staining, and cell adhesion tests using L929 fibroblasts verified the excellent cytocompatibility of PBCA adhesives, with cell viability maintained above 90
In perovskite solar cells, the thickness and refractive index of each layer are critical factors that determine light absorption, thereby directly influencing overall device performance. However, systematic experimental evaluation of a wide range of structural parameters is impractical due to the large parameter space and the associated time and cost constraints. Therefore, optical simulation methods are widely used as essential tools for device design and optimization. However, the assumptions of perfectly flat structures in typical simulations can lead to discrepancies from real devices. In this study, we incorporate measured morphology into the optical model and investigate their influence on device absorption. We analyze how interfacial structure influences the optical response of perovskite solar cells. When interfacial roughness is included, the interference induced fluctuations observed in the planar model are reduced. Especially, bottom interface roughness plays a significant role in mitigating the optical interference originating from the front side. These results show that considering realistic device structures is essential for accurately understanding and designing high-efficiency perovskite solar cells.
Efficient lithium extraction from lithium resources is of great significance for the continued development of various lithium-powered electronic technologies. We herein report polynorbornene resins incorporating triethylene glycol (triEG) as an economically viable lithium-chelating ligand. The resins were prepared by ring-opening metathesis polymerization (ROMP) of triEG-functionalized norbornene monomer and bis-norbornene as a crosslinker. The synthesized resins captured up to 46
Lithium metal batteries (LMBs) are promising candidates for next-generation energy storage systems due to their high theoretical energy density. However, lithium dendrite growth and safety concerns remain critical challenges. To address these issues, we propose a novel gel polymer electrolyte (GPE) design strategy by coating a PEGDE/PEA-based crosslinked polymer (PEGA) electrolyte onto a commercial polypropylene (PP) separator, which serves as a structural substrate. The PEGA gel polymer electrolyte exhibited enhanced mechanical properties, representing an improvement of 15
Rheumatoid arthritis (RA) is driven by complex immune dysregulation in which innate immune cells—including dendritic cells, macrophages, and neutrophils—play pivotal roles in initiating and amplifying synovial inflammation. Despite the central roles of these cells, conventional therapies often lack the precision to selectively target these specific cell subsets, leading to systemic off-target effects. In this context, nanotechnology offers a promising strategy to overcome these limitations by leveraging the unique phagocytic capacity and surface markers of innate immune cells for targeted delivery. Visual representation of nanoparticle-mediated immune and microenvironmental remodeling in RA
Ionic polymers are promising electrolyte materials but have inherent limitations when used alone. In this study, flexible network ionic polymer supports were prepared from a piperidinium bis(fluorosulfonyl)imide-based ionic monomer, n-butyl acrylate, and ethoxylated trimethylolpropane triacrylate (ETPTA). Composite electrolytes were fabricated by incorporating the organic ionic plastic crystal 1,2-bis(N-methylpiperidinium)ethane bis(fluorosulfonyl)imide and lithium bis(fluoro-sulfonyl)imide (LiFSI). The composite with a polymer-to-salt ratio of 7:3 and an OIPC-to-LiFSI ratio of 7:3 exhibited the highest ionic conductivity of 5.28 × 10−5 S cm−1 at 30 °C, which is more than ten times higher than that of the polymer containing only LiFSI. The composites were thermally stable up to 200 °C and electrochemically stable up to 5.5 V. demonstrating that introducing OIPC into a network ionic polymer matrix enhances ionic conductivity while maintaining stability and flexibility of polymer electrolyte materials. Ionic polymer composite electrolytes were prepared by incorporating network ionic polymer, organic ionic plastic crystal 1,2-bis(N-methylpiperidinium)ethane bis(fluorosulfonyl)imide and lithium bis(fluoro sulfonyl)imide (LiFSI)). One of the ionic composites with a polymer-to-salt ratio of 7:3 exhibits the highest ionic conductivity of 5.28 × 10−5 S cm−1 at 30 °C. They are thermally stable up to 200 °C and electrochemical stable up to 5.5 V, and can be a good candidate for polymer electrolyte systems of lithium secondary batteries.
Antibiotics are mainly utilized to treat microbial infections by inhibiting the growth of bacteria, fungi, and protozoa. Antibiotics at trace levels can induce antimicrobial resistance and toxicity to aquatic ecosystems. Amoxicillin is one of the most frequently used antibiotics with broad activity against bacteria. The adverse effects of amoxicillin on human health and the environment are uncertain, making it essential to establish an immediate, reliable method for its accurate determination. Here, we developed a novel β-CD (β-cyclodextrin) hydrogel for sensing the concentration of antibiotics in aqueous medium. The comprehensive characterization through FTIR, SEM, EDS, Mapping, TGA, XRD, BET, XPS, UV-visible, and fluorescence microscopy reveals the successful synthesis with photoluminescent properties. The hydrogel revealed dual emission characteristics with high intensity at 419 nm and 491 nm under 370 and 410 nm excitation, respectively. These clusteroluminescence (aggregation-induced emission) characteristics represent the extent of through-space interactions among functional groups present on the polymeric chains. The excitation wavelength-dependent luminescent behaviour deviating from Kasha’s rule arises from heterogeneous chromophores within the crosslinked network. Luminescence decay analysis supports clustering induced coexisting emissive states and delayed fluorescence. The β-CD hydrogel demonstrated 1.64-fold (at 370 nm) and 2.23-fold (at 410 nm) “turn-on” luminescence enhancement for amoxicillin, contrasting with the luminescence quenching by other pharmaceutical compounds. The selective and sensitive nanomolar detection of amoxicillin (linear range: 3–9 nM at 370 nm with LOD = 0.73 nM; 2–9 nM at 410 nm with LOD = 0.76 nM) was achieved along with pH stability, and recyclability, offering advantages for environmental monitoring applications.
Acellular dermal matrix (ADM), widely used as a biomaterial for soft tissue regeneration, possesses high biocompatibility and structural properties favorable for tissue regeneration, based on the characteristics of Human-derived skin tissue. Sheet-type ADM (SA) products are advantageous in stability shape, but may have poor flexibility when cutting or shaping to fit irregularly shaped defect areas. (ASS) is a biomaterial manufactured through recombinant skin powder to overcome these limitations. This biomaterial, which possesses a low density and shape-retaining properties similar to a sponge, was compared with SA for its applicability to soft tissue defects. In mechanical property results, the ASS group showed a significantly higher degree of moldability than the SA group and the similar shape stability after hydration. In vitro evaluation, ASS has non cytotoxicity, and in vivo evaluations demonstrated stable tissue engraftment accompanied by a normal inflammatory response. These results suggest that the ASS (a newly formulated ADM-based sponge scaffold) graft material is not simply a biomaterial for filling tissue defects; it has potential for application in tissue implantation fields requiring diverse clinical requirements.
Mechanical recycling of polyamide 66 (rPA66) represents a promising strategy to enhance material circularity in engineering plastics. However, repeated thermal and hydrolytic degradation induces severe chain scission, leading to reduced molecular weight, and deterioration of mechanical and rheological properties. To overcome these limitations, epoxy-functional chain extenders (CEs) composed of styrene, methyl methacrylate (MMA), and glycidyl methacrylate (GMA) are synthesized and applied to rPA66 via reactive extrusion at concentrations of 1, 3, and 5 parts per hundred resin (phr). Torque rheometry and oscillatory shear measurements reveal significant increases in melt viscosity and elasticity, confirming effective chain rebuilding and the formation of long-chain branched architectures. Differential scanning calorimetry shows that low extender contents slightly enhance crystallization temperature and crystallinity due to heterogeneous nucleation, whereas higher loadings lead to decreases in melting and crystallization temperatures as a result of restricted chain mobility. Tensile testing demonstrates pronounced improvements in elongation at break and toughness with increasing extender content, particularly for rPA66/ADR. Notably, the incorporation of 3–5 phr ADR results in more than a threefold increase in elongation compared to neat rPA66 while maintaining acceptable tensile strength. However, the higher reactivity of ADR causes greater disruption of crystallization, leading to a lower modulus relative to the synthesized CE at equivalent loadings. Consequently, this study highlights the critical role of chain extender architecture in balancing stiffness, toughness, and processability for upgrading rPA66. Chain extension of rPA66 using as-synthesized random copolymer type epoxy-functional chain extender enables improved rheological and mechanical properties.
Passive daytime radiative cooling (PDRC) has emerged as a promising energy-free cooling strategy; however, many high-performance coatings rely on organic solvents and suffer from durability and contamination issues under outdoor conditions. In this study, we develop an eco-friendly waterborne acrylic/CaCO3 composite coating that simultaneously achieves efficient radiative cooling and hydrophobic easy-cleaning. Micro-sized CaCO3 particles induce strong solar reflectance through Mie scattering, while the acrylic binder provides high mid-infrared emittance via intrinsic molecular vibrations. The optimized film with 70 vol
We report the synthesis and application of UV-curable polyurethane acrylate (PUA) dielectrics with high dielectric constant (high-k) properties for low-voltage organic thin-film transistors (OTFTs) and integrated logic circuits. Two PUA variants, MGH1000 and MGH3000, were synthesized by varying the molecular weight of the polyol precursors, enabling control over chain flexibility and dipolar polarization. Upon UV curing, both materials formed densely crosslinked networks with excellent mechanical and thermal stability. The dielectric films exhibited high k values (> 8), low leakage current densities (< 10−8 A cm−2 at 2 MV cm−1), and minimal frequency dispersion, particularly in MGH3000. These characteristics enabled the fabrication of high-performance OTFTs with low operating voltages (≤ 5 V), high field-effect mobility (up to 7.9 cm2 V−1 s−1), low subthreshold swing, and strong bias stress stability. Furthermore, photopatterned MGH dielectrics were integrated into functional NOT, NAND, and NOR logic gates, demonstrating reliable logic operation under low-voltage conditions. The combination of photo-patternability, high-k performance, and processing compatibility highlights the potential of these PUA dielectrics for next-generation organic electronics. UV-crosslinkable high-k polyurethane acrylate dielectrics enable low-voltage OTFTs and integrated logic circuits with reliable performance and photopatternability
The development of multifunctional nanocomposite fibers that combine dielectric performance, thermal stability, and antimicrobial activity is of increasing importance for advanced flexible electronics and antimicrobial surface technologies. In this study, PVA-CMC-SA/5
