Beilstein Journal of Nanotechnology最新文献

The superconductor-insulator-normal metal-insulator-superconductor (SINIS) tunnel junction structure is the basic building block for various cryogenic devices. Microwave detectors, electron coolers, primary thermometers, and Aharonov-Bohm interferometers have been fabricated by various methods and measured at temperatures down to 100 mK. The manufacturing methods included Dolan-type shadow evaporation, Manhattan-type shadow evaporation, and magnetron sputtering with selective etching of superconducting and normal metal electrodes. Improvement in ultimate sensitivity is achieved by suspending the absorber above the substrate. Best responsivity of up to 30 electrons per photon at a frequency of 350 GHz, or 72000 A/W, and voltage responsivity up to 3.9 × 10⁹ V/W were obtained with a black body radiation source and series of band-pass filters. The specially designed SINIS arrays are intended to detect 90 GHz radiation at the "Big Telescope Alt-azimuthal" (romanized Russian: "Bolshoi Teleskop Alt-azimutalnyi", BTA) with noise equivalent power of less than 10^-16 W·Hz^-1/2. The receiver in a ³He cryostat with an optical window was mounted at the Nasmyth focus of the BTA and tested at a temperature of 260 mK with a IMPATT diode radiation source.

Lipid nanoparticles (LNPs) have become significant vehicles in the delivery of therapeutic substances, particularly for nucleic acid vaccines and gene therapies. A key component in the nanoparticle formulation is polyethylene glycol-modified (i.e., PEGylated) lipids (PEG lipids), which can significantly influence the stability, cell interactions, and overall effectiveness of LNP delivery vehicles. This review collates insights into the role of PEG lipids in LNPs by illustrating how the PEG chains arrange on the nanoparticle surface and the potential impacts on LNPs' physicochemical properties by varying surface PEG density or PEG chemistry. Subsequently, PEG conformations are discussed in terms of their modulation of protein corona formation, cellular uptake, and immunogenic responses, particularly the pathways of anti-PEG antibody production and complement activation. Building on these understandings, functionalized PEG lipids are reviewed for ligand conjugation and targeted LNP delivery function. Promising alternatives to replace the benchmark PEG lipids are also systematically reviewed to address PEGylation associated immunogenicity. By conducting a critical analysis of the recent literature and identifying potent candidates for PEGylation strategies or PEG-free platforms, this review aims to provide insights and support the advancement of LNP mediated delivery.

Mosquitoes of the Aedes genus are responsible for the transmission of arboviruses that seriously affect public health. Given the increasing resistance to traditional insecticides and their negative environmental impacts, the need for safer alternatives arises. In this context, natural produts such as essential oils (EOs) have been studied for their larvicidal and repellent properties against Aedes aegypti, due to the presence of compounds such as terpenoids and phenols. However, the usage of EOs is limited due to some properties such as poor water solubility, high volatility, and intrinsic oxidation sensitivity. Thus, the development of novel formulations to efficiently deliver bioactives represents an innovative approach for Aedes aegypti control. In this context, nanothecnology provides smart formulations with improved drug solubility, controlled release, and protection against degradation. Nanoemulsions are colloidal systems with droplets of 20 to 500 nm, which improve the dispersion of the compounds, protect their active properties, and enhance their efficacy. This review addresses the potential of nanoemulsions as efficient carriers of EOs, and how this approach could emerge as ecological alternatives to synthetic insecticides. Herein, the focus was kept on targeting larvicidal and repellent activities against Ae. aegypti. For that, 23 studies were analyzed, which demonstrated a significant increase in the efficacy of nanoemulsions with EOs compared to that of free EOs, in both activities. However, the repellent activity has been less explored, present in only three of the studies evaluated, in the last 10 years. Correlatingh with this, other aspects such as botanical species of EOs, mechanisms of action, composition, and characteristics of nanoemulsions are discussed. In addition, this review highlights challenges and perspectives on pharmaceutical nanotechnology towards nanoemulsions as safe, effective, and eco-friendly tools for controlling Ae. Aegypti.

We demonstrate the programmable control of kinetic soliton dynamics in all-Josephson-junction (all-JJ) networks through a novel tunable cell design. This cell enables on-demand switching of transmission lines and operates across defined parameter regimes supporting diverse dynamical modes. By introducing a structural asymmetry into a transmission line, we implement a Josephson diode that enforces unidirectional soliton propagation. The programmability of the kinetic inductance then provides a crucial mechanism to selectively enable or disable this diode functionality. By engineering artificial inhomogeneity into the circuit architecture, we enhance robustness in all-JJ logic circuits, 2D transmission line all-JJ lattices, and neuromorphic computing systems.

We demonstrate atomic force microscopy (AFM) imaging with a microcantilever force transducer where an integrated superconducting microwave resonant circuit detects cantilever deflection using the principles of cavity optomechanics. We discuss the detector responsivity and added noise, pointing to its crucial role in the context of force sensitivity. Through analysis of noise measurements we determine the effective temperature of the cantilever eigenmode and we determine the region of detector operation in which the sensor is thermal-noise-limited. Our analysis shows that the force-sensor design is a significant improvement over piezoelectric force sensors commonly used in low-temperature AFM. We discuss the potential for further improvement of the sensor design to achieve optimal detection at the standard quantum limit. We demonstrate AFM operation with surface-tracking feedback in both amplitude-modulation and frequency-modulation modes.

Marine organisms such as barnacles rely on a complex underwater adhesive system, driven by self-assembly and intermolecular associations between cement proteins, for permanent attachment to a variety of surface types. In this study, we investigated the influence of environmental parameters on the self-assembly of recombinant cp19k, a key adhesive protein in Pollicipes pollicipes. Using TEM imaging, a low pH (4.0) and high salt concentration (600 mM NaCl) environment, mimicking P. pollicipes gland conditions, was identified to promote the formation of extended, needle-like fibrils by the cp19k protein. The β-amyloid nature of fibrils formed under these conditions and at high pH/low salt concentration was confirmed by Thioflavin T assay. Non-fibrillar cp19k adhered most effectively to hydrophilic and hydrophobic surfaces under low pH/low salt concentration conditions, while pre-formed fibrils retained their adhesion ability upon switching to a high pH/high salt concentration environment, which was designed to mimic the change in the protein environment upon secretion in vivo. These findings support the hypothesis that fibril formation occurs in the acidic, iso-osmotic gland of the barnacle, with delayed cement curing enabling fibril secretion for sustained adhesion of the organism. The study provides insight into the environmental sensitivity of cp19k structure-function dynamics and may support the design of bioinspired adhesives and biomaterials.

The growing interest in green-synthesized metallic nanoparticles reflects a global shift toward sustainable, eco-friendly technologies in biomedical innovation, particularly in dentistry. This scoping review examines the rising focus on these nanoparticles regarding their antimicrobial, regenerative, and therapeutic potential in dental applications. Among the metals studied, silver and zinc oxide nanoparticles dominate because of their broad-spectrum antimicrobial activity and enhanced biocompatibility, achieved through phytochemically mediated synthesis. Conventional nanoparticle production often relies on toxic reagents and energy-intensive processes, posing environmental and clinical challenges. In contrast, green synthesis, using plant extracts, fungi, or bacteria, offers a sustainable alternative by leveraging natural reducing agents like polyphenols and flavonoids. These bioactive compounds not only facilitate nanoparticle formation but also improve stability and biological efficacy, making them ideal for dental applications such as caries prevention, endodontic disinfection, and periodontal regeneration. Our analysis of 98 studies reveals India as the leading contributor (78.6%), driven by its rich biodiversity and strong research infrastructure. Key plant families including Lamiaceae and Fabaceae were frequently employed due to their high phenolic content. Despite promising results, gaps remain, such as the predominance of in vitro studies (68.7%) and insufficient cytotoxicity assessments (47.8%), underscoring the need for translational research. This review highlights the transformative potential of green-synthesized nanoparticles in dentistry, merging technological advancement with ecological responsibility. Future work should prioritize clinical trials, long-term safety evaluations, and standardized protocols to fully realize their therapeutic benefits.

Leishmaniasis, caused by protozoa of the genus Leishmania spp., is a neglected tropical disease that poses a significant challenge to the public health in tropical and subtropical regions, affecting mainly low-income individuals. Current therapies are limited due to severe adverse reactions to currently available drugs, high cost, low patient adherence, and even the emergence of resistant strains. Examining safer and more effective alternatives, natural compounds such as phytol - a diterpene derived from chlorophyll - have attracted attention due to their broad biological activities. To increase their solubility, stability, and cell delivery, nanotechnology-based systems, such as nanoemulsions (NEs), represent a promising approach. In this study, soybean oil nanoemulsions loaded with phytol (PHYT-NE) were developed using the phase inversion composition (PIC) method, and then characterized and evaluated. The PHYT-NE had a mean droplet diameter close to 200 nm, a polydispersity index of less than 0.2, spherical shape, and a pH value compatible with cutaneous application. The formulation showed high colloidal stability for at least 30 days of storage and at least 15 days even under stress conditions, with no signs of macroscopic instability or changes in droplet size. The cytocompatibility of NEs was confirmed in 3T3 fibroblasts at the concentrations tested, indicating potential safety for in vivo trials. Notably, PHYT-NE exhibited significant time-dependent leishmanicidal activity against Leishmania amazonensis promastigotes, with lower IC₅₀ values (up to five times lower at 48 hours) and up to 75% parasite death after 48 hours, showing greater antiparasitic activity compared to that of free phytol. Although the use of promastigotes represents a limitation, this model was used as a proof-of-concept, with promising evidence of the potential of PHYT-NE. Future studies in macrophage models infected with intracellular amastigotes will be essential to confirm the observed efficacy and validate the potential of PHYT-NE as a safe and effective topical therapy for cutaneous leishmaniasis.

The widespread use of plastic has led to microplastics (MPs) being released in many water sources. MP contamination in water supply systems is a global concern due to their persistence and ability to adsorb toxic pollutants. Despite having effectiveness, conventional water treatment processes still have limited efficiency in removing MPs, especially smaller particles. Thus, it requires researchers to develop effective and sustainable strategies to deal with this matter. Many studies have shown that adsorbent nanomaterials have potential for the removal of MPs from water. This review evaluates the current status of using adsorbent nanomaterials in removing MPs from water supply systems. It discusses the occurrences and removal efficiency of MPs in water supply systems, as well as the mechanisms and performance when applying these materials for treatment. In addition, the related risk of adsorbent nanomaterials is also considered. Microplastics from land-based sources and wastewater plants persist in water supplies, with conventional treatments removing only 40-70%, especially struggling with smaller particles. Based mainly on mechanisms like electrostatic interactions, hydrophobic interactions, pore filling, hydrogen bonding, π-π stacking, and surface complexation, adsorbent nanomaterials achieve over 90% removal of MPs and can recovery. Their effectiveness depends on material properties and environmental factors, but challenges remain in scale-up and related risks. Adsorbent nanomaterials show promising potential to enhance MP removal through specific properties. Although some related risks are discussed, these materials provide a foundation for developing sustainable, effective solutions to mitigate MPs pollution in the water supply system.

Recent research in alternate sources of energy such as piezoelectric energy conversion devices has positioned layered double hydroxides (LDHs) as promising candidates among the other two-dimensional materials. With their unique flexible layered structure, LDHs hold great potential for piezocatalysis and powering smart wearable electronics. Despite their promise, this area of study is still in its infancy and this review explores its recent advances. The discussion encompasses LDH-based piezoelectric nanogenerators, piezocatalytic and piezo-photocatalytic properties of LDHs, and composite material synergies that enhance the overall electroactive performance. Looking to the future, systematic research into the effects of LDHs' composition and structure on piezoelectric properties will be crucial to unlock their full potential. This mini-review aims to inspire the audience with valuable ideas for the development of new LDH-based piezoelectric materials, thereby contributing to the development of next-generation high-performance piezoelectric devices.