Science and Technology of Advanced Materials最新文献

Hybridization chain reaction (HCR), which typically consists of two hairpins for signal amplification, has emerged as a versatile tool in bioanalytical applications. Here, a novel HCR nanowire based on a single DNA hairpin structure is reported. The hairpin stem is rationally engineered with a palindromic sequence, which enables a self-hybridization chain reaction (SHCR) upon the introduction of the initiator DNA strand. Compared to the conventional two hairpin-based HCR nanowire, the single DNA hairpin-based SHCR nanowire achieves nearly a two-fold improvement in the signal-to-noise ratio and exhibits better selectivity for single-base mismatch. By integrating the initiator DNA strand with adenosine triphosphate (ATP) aptamer, the single DNA hairpin-based nanowire has been applied for sensitive ATP detection, capable of monitoring ATP both in living cells and that released from dead cancer cells post-radiotherapy. The SHCR nanowire we proposed here has significantly simplified the sequence design of HCR and holds promise as a potential alternative to the conventional HCR nanowire.

The origin of nonlinear stress behaviors in transient networks during oscillatory shear measurements is investigated in this study via two-dimensional rheo-optics observations of a systematically controlled model system comprising tetra-armed polyethylene glycols (Tetra-PEG slime). Transient networks are characterized by their temporary crosslinks. However, the strain scale at which nonlinear viscoelastic responses begin to emerge under strain amplitude sweep in oscillatory shear deformations remains poorly characterized. The uncertainty of nonlinear onset can be attributed, at least in part, to the heterogeneous structures inherent to conventional transient networks, as well as to the limited availability of detailed experimental evaluations. We overcome these limitations by employing Tetra-PEG slime, which possesses a well-defined network structures with uniform strand lengths and functionalities. Rheo-polarization imaging reveals homogeneous deformation in the linear regime and a scaling change of retardation - strain relation around the onset of nonlinearity. Meanwhile, Rheo-SAXS measurements confirmed the absence of nanoscale structural changes. The elastic contribution per network strand at the critical strain (W _c,0) approximately collapses onto a single master curve when plotted against the Weissenberg number (Wi_max), following the relation W _c,0 ∝ Wi_max ². This scaling suggests that the onset of nonlinearity is governed by the balance between molecular relaxation and applied deformation. These findings provide molecular-level insights into the nonlinear elasticity of transient networks and offer a framework to design soft materials with tunable nonlinear responses.

Understanding how nano- and microparticles interact with biological systems is essential for advancing the biomedical applications of engineered materials. These interactions are governed not only by the physicochemical properties of the particles - such as size, shape, and surface chemistry - but also by host-specific physiological factors. However, how intrinsic host factors, particularly age and biological sex, affect interactions between immune cells and particles remains poorly understood. In this study, we systematically investigated how these intrinsic host variables influence the cellular uptake of polymeric particles by primary macrophages. Using a library of particles with controlled sizes (25, 250, and 3000 nm) and surface chemistries (unmodified, amine-, and carboxyl-functionalized), as well as with biological particles (bacteria and yeast), we compared uptake efficiencies in macrophages derived from male and female mice of various ages. We observed significant age- and sex-dependent differences in particle internalization. Transcriptomic profiling revealed differentially expressed genes related to receptor-mediated endocytosis and actin cytoskeleton remodeling, suggesting that molecular mechanisms underly these variations. Additionally, protein coronas were formed by incubating polymeric particles with autologous serum, revealing sex-dependent differences in corona composition and resulting macrophage recognition. Our findings highlight the critical interplay between engineered-material properties and host biological variability. Accordingly, this work provides key insights for the rational design of nanomaterials tailored to perform consistently across heterogeneous biological populations, thereby advancing the development of personalized nanomedicine and immunomodulatory materials.

Stimuli-responsive microgels that exhibit rapid changes in size in response to external stimuli such as pH and temperature are of great interest for the development of smart sensors, drug delivery carriers, and separation materials. This paper describes the preparation of molecule-responsive microgels with molecular recognition sites comprising a hydrophilic network via inverse miniemulsion polymerization using a water-soluble emulsifier. The water-soluble emulsifier comprising hydrophilic poly(sulfobetaine) and hydrophilic/oleophilic poly[oligo(ethylene glycol)methacrylate-co-2-(2'-methoxyethoxy)ethyl methacrylate] blocks were synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization. The resulting block copolymer, PSB-POEG, stabilized the water-chloroform interface in a water-in-oil (W/O) emulsion. Water droplets in a W/O emulsion stabilized with PSB-POEG allowed the inverse miniemulsion polymerization of acrylamide (AAm), acryloyl-modified β-cyclodextrin (CD), and N,N'-methylenebisacrylamide to obtain CD-conjugated PAAm microgels with a diameter of approximately 150 nm. The resulting CD-PAAm microgels were stably dispersed in an aqueous medium by the addition of water, followed by evaporation of chloroform. The CD-PAAm microgels exhibited rapid shrinkage in response to bisphenol A (BPA) owing to the formation of CD-BPA-CD complexes acting as dynamic cross-links. The proposed method for preparing hydrophilic microgels by inverse miniemulsion polymerization using a water-soluble emulsifier allows the preparation of molecularly imprinted and bioconjugated microgels, providing a useful platform for designing rapidly responsive soft nanomaterials for molecular sensors, separation substrates, and drug delivery carriers.

As an extension of fiber-reinforced plastics, research on fiber-reinforced soft hydrogels has attracted remarkable attention. From the perspective of sustainability, it is desirable to use biopolymers such as cellulose and chitin as the fibrous phase of these hydrogel composites. However, obtaining biopolymer-based fibers from plants or fungi generally requires environmentally harmful processes such as extraction, purification, and reconstruction of the target biopolymers. To avoid this problem, this study aimed to obtain tough biopolymer/hydrogel composites with minimal environmental impact. Specifically, minimally processed eringi (king oyster mushroom) and kanpyo (dried shaved gourd) were directly used as the fibrous phase, and hydrogel matrices were prepared within them to make the bio-composites. The hierarchical fibrous structure of the biopolymers inherently present in eringi and kanpyo was well preserved in the bio-composites. The resulting composites exhibited high strength and toughness originating from the well-aligned fibrous biopolymers in the bio-composites.

Understanding how large-pore zeolites respond to high-pressure conditions is essential for optimizing their structural stability and functional performance. In this study, we systematically investigated the compressibility and pressure-induced hydration (PIH) behavior of ion-exchanged mordenites using synchrotron X-ray powder diffraction under water-mediated conditions. The results reveal that the hydration level and spatial distribution of extra-framework cations (EFCs) at ambient conditions critically determine the initial number and arrangement of water molecules within the 12-membered ring (12MR) channels. Samples with weakly hydrated EFCs (e.g. Cs-MOR, Na-MOR) undergo a phase transition from Cmcm to Pbnm at about 1.6(1) GPa, because they fail to maintain the structural stability of the framework as compressed in water. In contrast, samples with EFCs strongly hydrated and uniformly distributed near the channel center (e.g. Sr-MOR, Eu-MOR) have lower compressibility, compared to cations aggregated near the channel wall (e.g. Pb-MOR, Cd-MOR). This study demonstrates that PIH acts as a structural buffer that stabilizes the framework by preventing pore collapse, thereby enhancing the compressibility in water. These findings underscore the critical role of the ambient EFC hydration state and PIH in governing the mechanical response of mordenite. The insights provide a basis for tailoring zeolite frameworks with optimized structural buffering effects for advanced industrial applications and geoscientific processes under extreme conditions.

Two-dimensional transition metal carbides and nitrides, so-called MXenes, hold significant promise as flexible transparent conductive electrodes (TCEs) in diverse applications. However, MXenes fall below the minimum requirements for industrial use, largely due to factors such as the quality of MXene flakes, electrical conductivity, optical conductivity, and transparent electrode fabrication techniques. In this study, we analyze the relationships among nanosheet size, DC- and optical conductivity and its ratio ( ${\sigma }_{\mathrm{DC}}$ / ${\sigma }_{\mathrm{op}}$ ), and sheet resistance (R _s) of MXene TCEs based on data from published literature. Compared to Ti₃C₂T _x TCEs fabricated with low-quality, small-sized flakes ( <1 μm, ${\sigma }_{\mathrm{DC}}$ / ${\sigma }_{\mathrm{op}}$  < 10), those made with high-quality, large-sized nanosheets ( >6 μm, ${\sigma }_{\mathrm{DC}}$ / ${\sigma }_{\mathrm{op}}$  > 20) with narrow size distributions exhibit dramatically reduced R _s by several orders of magnitude while maintaining high transmittance. Nevertheless, the ${\sigma }_{\mathrm{DC}}$ / ${\sigma }_{\mathrm{op}}$ of continuous Ti₃C₂T _x metallic TCEs saturates at ~24, fairly below the basic requirements for commercial TCEs. By integrating a metallic silver grid onto Ti₃C₂T _x TCEs, a remarkable ${\sigma }_{\mathrm{DC}}$ / ${\sigma }_{\mathrm{op}}$ ratio of 330 has been achieved, bringing MXene TCEs closer to fulfilling industrial application standards and inspiring greater confidence in their future adoption. Beyond the field of TCEs, the insights gained here could inspire advancements in other areas, such as optoelectronic devices, flexible displays, and energy-efficient transparent technologies. This work provides a framework for the design and development of next-generation transparent conductive materials with broad implications across various scientific and industrial domains.

Polymercoated carbon nanotubes (CNTs) provide defectfree interfacial control for sensors, thermoelectric, electrochemical and bio devices. We review roles of coated polymers for applications of polymer-coated CNTs for sensors, thermoelectric, batteries and biological applications.

In response to the evolving demands in energy storage, the review underscores the critical need for ongoing research in battery technology, specifically centred to indispensable role of Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) which aims to characterize the intricate components of all kind of batteries. This article extensively examines SIMS applications, illuminating aspects such as chemical compositions, structural arrangements, electronic behaviours, and various parameters like bulk and grain diffusion coefficients. All these effective parameters analysis extends to the discussion of in-situ studies, suggesting the potential for operando SIMS and emphasizing their vital role in real-time monitoring during battery operations. These studies unveil intricate interactions at solid-solid interfaces, exerting a significant influence on overall battery performance. By spotlighting recent advances and emerging trends, the review summarizes and examines case studies by various researchers on the use of SIMS for analysing battery-related materials.