Small

Journal: Small

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Wiley-VCH

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1613-6810
1613-6829

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Publications 1 - 10 of 134

Resizing Metal-Coated Nanopores Using a Scanning Electron Microscope
Chansin, Guillaume A.T.; Hong, Jongin; Dusting, Jonathan; et al. (2011)
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Shaping Magnetic Hyperthermia Properties through Nanoparticle Surface‐Ligand Design: Implications for Cellular Responses
Hertle, Lukas; López‐Ortega, Alberto; Ye, Hao; et al. (2025)
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Magnetic iron oxide nanoparticles have attracted increasing attention for their potential use in biomedicine over the last few decades. Their inherent characteristics have enabled novel therapeutic approaches such as magnetic hyperthermia. To maximize the therapeutic efficacy, several research efforts have been focused on the optimization of these nanoparticles in terms of their size, morphology, and crystal structure etc. However, no consensus has been reached regarding the optimal surface design. To gain deeper insight into this complex phenomenon, the influence of a variety of surface ligands on the magnetic, hyperthermic, and colloidal behaviors of the magnetic iron oxide nanoparticles, along with their influence on cellular viability, is investigated. The results revealed that the molecular structure of the ligands, including both the anchoring group and molecular chain, plays a critical role in determining the above-mentioned properties and performance. This work lays the groundwork for surface engineering of magnetic nanoparticles, emphasizing the need to consider the magneto-hyperthermic performance, colloidal stabilities, and the cellular interactions as interconnected factors that critically influence their clinical applicability.
Targeted Additive Micromodulation of Grain Size in Nanocrystalline Copper Nanostructures by Electrohydrodynamic Redox 3D Printing
Menétrey, Maxence; Koch, Lukas; Sologubenko, Alla; et al. (2022)
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The control of materials’ microstructure is both a necessity and an opportunity for micro/nanometer-scale additive manufacturing technologies. On the one hand, optimization of purity and defect density of printed metals is a prerequisite for their application in microfabrication. On the other hand, the additive approach to materials deposition with highest spatial resolution offers unique opportunities for the fabrication of materials with complex, 3D graded composition or microstructure. As a first step toward both ‒ optimization of properties and site-specific tuning of microstructure ‒ an overview of the wide range of microstructure accessed in pure copper (up to >99.9 at.%) by electrohydrodynamic redox 3D printing is presented, and on-the-fly modulation of grain size in copper with smallest segments ≈400 nm in length is shown. Control of microstructure and materials properties by in situ adjustment of the printing voltage is demonstrated by variation of grain size by one order of magnitude and corresponding compression strength by a factor of two. Based on transmission electron microscopy and atom probe tomography, it is suggested that the small grain size is a direct consequence of intermittent solvent drying at the growth interface at low printing voltages, while larger grains are enabled by the permanent presence of solvent at higher potentials.
Designing Stable Graphitic Networks on Ultra-Porous Polyimide Aerogels via Solvent-Guided Structuring
Wu, Tingting; Li, Mengmeng; Gao, Mingxiang; et al. (2025)
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Lightweight, highly porous polyimide (PI) aerogels have emerged as promising candidates for advanced electronic applications due to their exceptional thermal stability, mechanical performance, structural integrity, and low dielectric loss. However, the controlled laser-induced graphitization (LIG) of such ultra-porous polymeric networks remains a critical challenge, as localized high temperatures often trigger polymer backbone degradation and framework collapse. Herein, a chemically engineered PI aerogel via a molecular design strategy that tailors solvent–polymer interactions during gelation to produce a hierarchically porous yet thermally robust network is reported. This substrate preserves its porosity and integrity during high-intensity LIG, enabling the formation of a uniform graphene–carbon conductive phase embedded within the polyimide matrix. The resulting material achieves sheet resistivity as low as 6.5 Ωsq⁻¹, while retaining excellent dielectric properties (ɛr = 1–2, tan δ <0.2) and thermal insulation (30–35 mW m⁻¹ K⁻¹ post-300 °C treatment). This synergy between molecular design, thermal response, and electronic functionality enables integration into multifunctional devices, such as flexible pressure sensors, thermal management layers, and ultralight antennas, demonstrated by a reflection coefficient of −14 dB at 5.4 GHz and a peak gain of 3.9 dBi.
Hybrid Helical Magnetic Microrobots Obtained by 3D Template-Assisted Electrodeposition
Zeeshan, Muhammad A.; Grisch, Roman; Pellicer, Eva; et al. (2013)
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Ultrafast Intermolecular Dynamics of Nanoconfined Water in Swollen Lipid Cubic Mesophases
Zunzunegui-Bru , Eva; Alfarano , Serena Rosa; Züblin, Patrick; et al. (2025)
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Understanding the structure and dynamics of the hydrogen-bond network of water in topologically distinct swollen lipidic mesophases, is fundamental for their application in biomedical, pharmaceutical, and food science fields. Here, a positive and non-linear correlation between water hydrogen-bond dynamics and interfacial water population is uncovered in inverse bicontinuous swollen mesophases across an extended temperature range (298–340 K). Particularly, small-angle X-ray scattering determines the mesophase's structural features, uncovering a temperature-driven re-entrant phenomenon (reappearance) of (Formula presented.) phase upon heating. This topologically rich environment, however, has no detectable impact on the temperature dependence of the intermolecular modes of water, as revealed by terahertz absorption spectroscopy. Specifically, these modes show distinct dynamics: the stretching mode exhibits longer lifetimes than the libration mode, yet with a higher temperature-dependence, with approximately two-fold lower Arrhenius activation energies. In contrast, both stretching and libration modes exhibit a monotonic decrease in lifetime with increasing temperature, due to the increasing disruption of the hydrogen-bond network. Atomistic molecular dynamics simulations enable the quantification of interfacial water population, which shows a positive correlation with intermolecular lifetimes in a nonlinear manner, revealing a non-additive coupling between interfacial water population and water hydrogen-bond network dynamics within these systems.
Colloidal Crystallization of Virus-Like Particles with Polycations
Tran, Bettina; Keys, Timothy Gerard; Radiom, Milad; et al. (2025)
Small
Virus-like particles (VLPs) are protein nanocages capable of encapsulating or attaching guest molecules. Unlike viruses, they do not replicate in cells, making them promising candidates for advanced biomaterial design, particularly for biomedical applications such as drug delivery. However, the mechanisms governing VLPs self-assembly into highly ordered suprastructures with enhanced functionality remain largely unexplored. This study investigates the development of pH-responsive biomaterials using the icosahedral Acinetobacter phage coat protein AP205 VLPs, which has a diameter of ≈28 nm. Small-angle X-ray scattering, dynamic light scattering, and zeta-potential measurements reveal that AP205 VLPs self-assemble with the polycation poly[2-(methacryloyloxy)ethyl] trimethylammonium chloride (pMETAC) into highly ordered suprastructures. The structural organization is strongly influenced by composition, pH, and ionic strength. The findings provide insights into the directional interactions governing VLPs self-assembly with polycations and can guide the design of advanced, tunable VLP-based biomaterials.
Helical and Tubular Lipid Microstructures that are Electroless-Coated with CoNiReP for Wireless Magnetic Manipulation
Schuerle, Simone; Pané, Salvador; Pellicer, Eva; et al. (2012)
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“On-The-Fly” Synthesis of Self-Supported LDH Hollow Structures Through Controlled Microfluidic Reaction-Diffusion Conditions
Mattera, Michele; Sorrenti, Alessandro; De Gregorio Perpiñá, Lidia; et al. (2024)
Small
Layered double hydroxides (LDHs) are a class of functional materials that exhibit exceptional properties for diverse applications in areas such as heterogeneous catalysis, energy storage and conversion, and bio-medical applications, among others. Efforts have been devoted to produce millimeter-scale LDH structures for direct integration into functional devices. However, the controlled synthesis of self-supported continuous LDH materials with hierarchical structuring up to the millimeter scale through a straightforward one-pot reaction method remains unaddressed. Herein, it is shown that millimeter-scale self-supported LDH structures can be produced by means of a continuous flow microfluidic device in a rapid and reproducible one-pot process. Additionally, the microfluidic approach not only allows for an “on-the-fly” formation of unprecedented LDH composite structures, but also for the seamless integration of millimeter-scale LDH structures into functional devices. This method holds the potential to unlock the integrability of these materials, maintaining their performance and functionality, while diverging from conventional techniques like pelletization and densification that often compromise these aspects. This strategy will enable exciting advancements in LDH performance and functionality.
Platelet Membrane Cloaked Nanotubes to Accelerate Thrombolysis by Thrombus Clot-Targeting and Penetration
Liu, Bin; Victorelli, Francesca; Yuan, Yu; et al. (2023)
Small
Thrombotic diseases have a high rate of mortality and disability, and pose a serious threat to global public health. Currently, most thrombolytic drugs especially protein drugs have a short blood-circulation time, resulting in low thrombolytic efficiency. Therefore, a platelet membrane (Pm) cloaked nanotube (NT-RGD/Pm) biomimetic delivery system with enhanced thrombolytic efficiency is designed. Nanotubes (NT) with an excellent clot-penetration properties are used to load a protein thrombolytic drug urokinase (Uk). Platelet-targeting arginine glycine-aspartic peptide (RGD) is grafted onto the surface of the nanotubes (NT-RGD) prior to cloaking. Multiple particle tracking (MPT) technique and confocal laser scanning microscope (CLSM) analysis are applied and the results show that the nanotubes possess a strong penetration and diffusion capacity in thrombus clots. After the Pm cloaking on NT-RGD/Uk, it shows a thrombus microenvironmental responsive release property and the half-life of Uk is six times longer than that of free Uk. Most importantly, NT-RGD-Uk/Pm exhibits a 60% thrombolytic efficiency in the FeCl3-induced thrombosis mouse model, and it is able to significantly reduce the bleeding side effects of Uk. This Pm-cloaked nanotube system is an effective and promising platform for the controlled and targeted delivery of drugs for the thrombus treatment.

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