Small Science最新文献

Aqueous zinc (Zn) metal batteries (AZBs) have emerged as highly promising candidates for large-scale energy storage systems because of their inherent safety and cost-effectiveness. However, their practical implementation remains constrained by parasitic side reactions and uncontrolled dendrite growth at the metallic Zn anode. Herein, a microenvironment-controlled additive strategy is proposed via employing phytic acid-functionalized montmorillonite (MPA) nanosheets as electrolyte additives for highly durable AZBs. The MPA nanosheets spontaneously assemble onto the surface of the Zn anode through interfacial self-adsorption, effectively suppressing parasitic reactions. Moreover, the regulation of interfacial chemistry enhances the zincophilic characteristic, enabling precise modulation of Zn²⁺ flux distribution and directing homogeneous Zn electrodeposition through spatially controlled ion coordination. As a result, the Zn||Zn symmetric cell with the MPA additives achieves a stable cycle for over 2800 h at 2 mA cm^-2. The assembled Zn||VO₂ full cell within the modified electrolyte maintains exceptional cycling stability of 89.5% after 1000 cycles. This work presents a facile and efficient microenvironment-regulated additive strategy for homogeneous Zn deposition, aimed at achieving highly reversible AZBs.

Laser-induced graphene (LIG) is formed by the conversion of certain carbon precursors when irradiated with a laser beam. Predesigned LIG patterns are scribed onto the precursor material in a low-cost and maskless process, which enables the fabrication of flexible and electrically conductive materials for various applications. This study explores the friction and wear behavior of LIG from a polyimide precursor. Line patterns with different widths (200, 100, 50, and 30 μm) are introduced to modify the friction properties. An ultraviolet laser source with a nominal beam size of 2 μm is used, as it allows to scribe patterns with smaller dimensions and at higher resolution compared to the more commonly applied infrared laser sources. A distinct correlation is established between the pattern and its friction behavior, where lowering the line size results in a decrease in the coefficient of friction (COF). The wear behavior is evaluated, revealing gradual wear of the protruding LIG roughness peaks and a change in the graphenic material, which reduces the COF during the running-in stage of the tribological testing. Due to its versatility in terms of precursor material, patterning options, and morphology modification, LIG represents a meaningful candidate for customized tribological applications.

Graphene-copper (Gr-Cu) composite conductors have demonstrated Gr-enhanced electrical and thermal properties. However, the conductors' coupled mechanical and electrical responses remain unexplored despite the importance of their mechanical flexibility and robustness. Here, the electromechanical behavior of a recently developed microscale Gr-Cu composite, called axially continuous graphene-copper (ACGC) wire, has been investigated by developing and utilizing a customized tensile testing method. Experimental studies have shown that 80 μm-diameter ACGC (hereafter ACGC80) wires exhibit 3.681% and 3.173% higher compared to as-received and annealed Cu wires, respectively. More importantly, the Gr-enhanced electrical performance of the ACGC80 has been observed even after significant plastic deformation under uniaxial tension. To be specific, the conductivity of ACGC80 is 3.139%, 3.144%, and 3.088% higher than that of annealed copper wire at 3, 6, and 9% strain, respectively. Analysis indicates that ACGC80 deforms by forming highly localized plastic deformation zones along its length. This result suggests that graphene in ACGC80 serves as an effective electron pathway even after applying a large strain because the pronounced damage to graphene is limited to only a small fraction of ACGC80. The ACGC80 conductor has great potential to advance emerging applications in flexible interconnects, wearable electronics, and high-power transmission for microchips.

Ti-MXene is a promising electrode material for supercapacitors. The layered structure of MXene expands due to swelling in electrolytes allowing the penetration of ions into the interlayers. A study of effects related to the match between the size of cations in hydrated or dehydrated state and the interlayer distance of MXene is performed here using operando X-ray diffraction (XRD) in capillary-size supercapacitors with alkali metal chloride electrolytes. The supercapacitors are studied during charging and discharging over several cycles revealing structural changes at both MXene electrodes. Experiments reveal an expansion of the MXene c-lattice in LiCl, NaCl, and KCl electrolytes (compared to the expansion in pure water) under an increase of applied voltage from 0 to 1 V and structural oscillations related to a change of polarity. The interlayer spacing of MXene remains close to the water-swollen state in RbCl, CsCl, and NH₄Cl electrolytes showing no further expansion as a function of applied voltage. Only rather small variations of interlayer spacing are found in H₂SO₄ electrolyte during tens of charge-discharge cycles. Analysis of the match between the sizes of ions and the width of MXene interlayers demonstrates that some cations and anions could be inserted into MXene interlayers only in dehydrated state.

Nanobiomedicine promises to revolutionize life quality and expectancy of patients with cognitive impairment and cancer malignancies, via unraveling key molecular processes related to their onset useful as biomarkers of disease to develop and improve the efficacy of therapies. However, it is still a challenge understanding and identifying these molecular mechanisms as biomarkers of disease, because of their high-level of polymorphism and nanoscale dimensions. Here, it provides a review work linking the potential and capabilities of atomic force microscopy (AFM) technologies in unraveling beyond imaging the common and hidden properties of transient and nanosized molecular processes in cancer and neurodegeneration. This study highlights the most prominent operational modes of AFM to achieve morphological, mechanical, and chemical characterization of the molecular processes leading to these diseases. Finally, it outlines the advantages of AFM compared with other techniques to guide newcomers and stakeholders toward potential future avenues opened by AFM methods in nanobiomedicine.

The minimally invasive repair of soft tissue defects remains a major clinical challenge due to the lack of biomaterials that simultaneously fulfill key requirements, including extrudability, strong adhesion, seamless integration, bioactivity, and appropriate mechanical properties. Here, a multifunctional double-network composite hydrogel is presented that is synthesized from modified hyaluronic acid (HA) and silk fibroin (SF) through a stepwise gelation process. The incorporation of ferric ions enables dynamic crosslinking of dopamine-grafted HA, resulting in the rapid formation of adhesive hydrogels with microporous structures. Sonication-induced β-sheets in SF form a secondary network, enhancing mechanical strength with reduced swelling and degradation. The inclusion of curcumin-loaded particles within the hydrogel promotes anti-inflammatory and antifibrotic activity by promoting macrophage polarization toward the reparative M2 phenotype and reducing TGF-β-induced fibroblast differentiation and collagen deposition. In situ injectability and printability of the hydrogel are demonstrated in ex vivo porcine vocal fold models. In vitro and in vivo biological evaluations in rat models confirm the cytocompatibility of the hydrogel and its ability to support cell penetration. Mechanical, structural, and biological results collectively support the applicability of this hydrogel as a minimally invasive solution for soft tissue defect repair, particularly in mechanically dynamic tissues such as the human vocal folds.

Heterostructured nanocrystals (HNCs) integrating dissimilar materials offer unprecedented functionalities for optoelectronics and bioimaging, yet their synthesis remains constrained by severe lattice mismatch (>5%) between crystallographically incompatible phases. To overcome this challenge, a sacrificial agent-assisted method is introduced to fabricate high-quality HNCs from materials with incompatible crystal structures and extreme lattice mismatches. Using ZnO nanocrystals as a sacrificial oxygen source, the method demonstrates the epitaxial growth of NaYF₄/YOF HNCs-combining hexagonal phase NaYF₄ and cubic phase YOF with a bulk lattice mismatch of 36%. This strategy suppresses shell self-nucleation and enables facet-selective heteroepitaxy by maintaining an ultra-low monomer concentration. Atomic-resolution characterization reveals a coherent interface between NaYF₄ {100} and YOF {311} planes, reducing the interfacial mismatch to 7.6%. This method operates efficiently across a wide temperature range (300-320 °C) with >92% yield, while morphology is tunable via Na⁺ additives. This approach facilitates the design of advanced metal fluoride/oxide HNCs for photonics, sensing, and catalysis, offering new opportunities for applications where lattice mismatch has previously limited heterostructure development.

Single-molecule localization microscopy (SMLM) data can reveal differences in protein organization between different disease types or samples. Classification of samples is an important task that allows for automated recognition and grouping of data by sample type for downstream analysis. However, methods for classifying structures larger than single clusters of localizations in SMLM point-cloud datasets are not well developed. A graph-based deep learning pipeline is presented for classification of SMLM point-cloud data over a field of view of any size. The pipeline combines features of individual clusters (calculated from their constituent localizations) with the structure formed by the positions of multiple clusters (supracluster structure). This method outperforms previous classification results on a model open-source DNA-PAINT dataset, with 99% accuracy. It is also applied to a challenging new SMLM dataset from colorectal cancer tissue. Explainability tools Uniform Manifold Approximation and Projection and SubgraphX allow exploration of the influence of spatial features and structures on classification results, and demonstrate the importance of supracluster structure in classification.

Immunogenic cell death (ICD) is an immunostimulatory process that can be induced by light-activated photosensitizers, but its mechanisms remain unclear, especially with lipid nanoparticle (LNP) formulations. In this study, a multivariate, data-driven analysis was conducted using a panel of five verteporfin(V)-LNPs to identify the attributes that lead to the greatest photochemically-induced exposure of ICD markers in pancreatic cancer cells. These attributes include varying production of Type I (radicals) or Type II (singlet oxygen) reactive oxygen species (ROS) upon 690 nm activation, localization in different organelles, variable cellular uptake efficiencies, and different phototoxicity levels. Using principal component analysis, we identified that, unexpectedly, Type I ROS is most strongly associated with ICD marker exposure, which leads to dendritic cell activation ex vivo, while Type II ROS shows the weakest association. Furthermore, V-LNP localization in the endoplasmic reticulum and mitochondria is most strongly associated with exposure of ICD markers, while lysosomal localization shows the weakest association. ICD marker exposure is proportional to the degree of phototoxicity and cellular uptake efficiency for all V-LNPs. These findings provide critical insights into the multiparametric mechanism underlying photochemical ICD induced by V-LNPs and can inform the rational design of photochemical LNP constructs for augmenting anticancer immune responses.

Regenerating dental tissues for craniofacial reconstruction remains challenging due to inadequate tissue organization and poor intercellular connectivity, often caused by residual biomaterials. Recapitulating key developmental processes, such as spontaneous cellular condensation and epithelial-mesenchymal interactions (EMI), is essential for engineering functional tissue architecture. This study introduces an innovative system that utilizes oxidized alginate (OA) microgels laden with high-density human dental stem cells to promote self-condensation and EMI. The OA microgels were prepared through sodium periodate oxidation and further optimized. In vitro studies demonstrated rapid self-degradation of OA, which promoted efficient cell condensation and robust 3D tissue formation. Following subcutaneous transplantation into mice, the cell-dense microgels exhibited functional integration with host tissues, along with robust vascularization and osteogenic differentiation. To demonstrate its potential for craniofacial regeneration, a tooth germ model (OA/Epithelium + OA/Mesenchyme) that mimics EMI was developed using embryonic dental epithelial and mesenchymal cells from Embryonic Day 14.5 mice. Immediate transplantation under the mouse kidney capsule resulted in bone organogenesis within two weeks. In summary, the OA microgel system provides initial mechanical support and then quickly degrades to enable critical cell-cell interactions that mirror organ development. Thus, this scalable and cost-effective approach holds significant promise for advancing dental tissue engineering.