Micro and Nano Systems Letters最新文献

One of the physical methods for obtaining magnetite nanoparticles (NPs) is electron beam physical vapor deposition (EB PVD), which requires complex equipment, but allows obtaining a significant amount of pure (ligand-free) NPs. The biomedical application of such NPs is less studied than materials from other synthesis methods. The objective is to study the effect of pure magnetite NPs in the NaCl matrix obtained by EB PVD on hematological indicators, gases, electrolytes and parameters of iron metabolism in the blood of intact animals. The physical characteristics of NPs were studied using high-resolution transmission electron microscopy, scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy mapping, electron energy-loss spectroscopy, selected area electron diffraction and fast Fourier transform. In vivo experiments were conducted on albino male rats, which were injected with solution of magnetite-sodium chloride NPs (1.35 mg Fe/kg). After 3 and 72 h, hematological parameters, blood gases, electrolytes, and serum iron were determined. The synthesized NPs had an average size of 11 nm. They were identified as magnetite, where polycrystals and single crystals were present. The absence of contamination in crystal boundaries, clear orientation and orderliness of atoms in crystals were established. The administration of NPs in the sodium chloride matrix to animals was characterized by a transient increase in the main indicators of red blood accompanied by an increase in the saturation of erythrocytes with hemoglobin and their mean volume after 3 h. It did not worsen blood gases and pH, but decreased blood Na⁺ content after 72 h. The investigated NPs caused changes in the parameters of serum iron characteristic to iron preparations, which after 3 h were smaller compared to the reference iron drug, and after 72 h—similar to it. More intense rapid effects on hematological parameters at lower serum iron indicate greater activity of the studied pure magnetite NPs obtained by EB PVD syntesis compared to the reference iron preparation.

The synthesis of a co-precipitated mixture of tantalum and brass nanoparticles (Ta and Cu/Zn) using a micro-wire-electro-discharge-grinding (µ-WEDG) with a combination of multiple process parameters is explained in this article. Tantalum and brass nanoparticles are produced in a dielectric medium Diel-7500 EDM oil. µ-WEDG represents a cutting-edge mechanical micro-machining technique extensively employed for machining micro rods. This method uses a grinding process that expels debris via melting and evaporation. This process disperses a fraction of nanometre-sized debris within the dielectric medium. Traditionally, this debris consisting of nanoparticles has been classified as unwanted substances and subsequently eliminated from the system. However, it now requires a thorough reassessment for possible usage. Hence, the characterization of tantalum and brass nanoparticles is conducted through Field emission Scanning Electron Microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analyses. The process parameters are capacitance, voltage and spindle speed. The investigation reveals that the mean nanoparticle size of produced tantalum nanoparticles range from 25 to 200 nm, while brass nanoparticles range from 300 to 950 nm. Furthermore, a notable correlation is observed between decreasing capacitance and the corresponding reduction in the shape and size of nanoparticles.

The purpose of this paper is to identify the relationship between human augmentation and personal combat ability improvement that overcomes physical and mental limitations according to the convergence of advanced science and technology such as biotechnology, brain engineering, and mems-based technology. We will first explain the background of the emergence of human augmentation and derive the characteristics of human enhancement through conceptual analysis of the correlation of human augmentation and cognitive abilities, which hold importance for future warfare. Afterward, through the development of brain engineering, we will present areas where advanced science and technology can contribute to improving military combat capabilities, such as cognitive abilities, decision-making abilities, situation recognition abilities, and brain stimulation. Finally, we will review the MEMS-based neural interface systems for the enhancement of human augmentation and individual combat ability.

Two types of cells targeting Peptides, TAMS-1 (CSPGAKVRCY {Lys (Biotin)}) and MDSC-peptide (Biotin {PEG4}-MEWSLEKGYTIK), were synthesized for targeting CD206 M2 macrophage and myeloid-derived suppressor cells (MDSC), respectively. Each peptide was coaxially electro sprayed where PCL (Polycaprolactone) is the core, and the peptide is the sheath to create a PCL nanoparticle with peptides. Electro spraying parameters included applying a voltage of 44 kV, humidity between 35–44%, tip to collector distance at 160 mm, core flow rate of 0.5 ml/hr, and a sheath flow rate of 0.7 ml/hr. UV–VIS (Ultraviolet–Visible) spectrometry, SEM (Scanning Electron Microscopy) imaging, and in vivo biodistribution techniques were used to study the morphology and performance of the PCL-peptide nanoparticles. Peak absorbance values for PCL were found at around 275 nm. Peptides absorbance value was observed between 230 and 250 nm. Scanning Electron Microscope image shows nanoparticles as small as 100 nm and agglomerates as large as 1 µm. In-vivo biodistribution of PCL and CD206 M2 macrophage targeting peptide (TAMS-1) nanoparticles after intravenous injection in the tumor mice model showed uptake to the tumors. On the other hand, MDSC peptide did not show any uptake to the site of tumors. Most activity is shown in the intestine indicating excretion of the agents through the hepato-biliary system.

Atomic Force Microscopy (AFM) has intrinsic tip-sample convolution artifacts. Commercially available tip-check samples are used to obtain only the tip radius, which can be used to deconvolute surface profiles or to quantify tip wear by relying on AFM alone. When the sample height is of the order of 100 nm or more, not only the tip radius but also the overall tip shape plays a key role in imaging. Therefore, it is necessary to know the overall tip shape, which requires a structured sample that is much larger than tip-check samples. Here, we propose to use deep reactive ion-etched holes of 1 µ diameter and 5 µ height to reconstruct the overall tip shape of three different AFM probes, namely conical, pyramidal and tetrahedral. The proposed cylindrical hole structure seems promising, as simple inversion of AFM images can provide sufficient collective features to be used for deconvolution and image enhancement.

Global public health confronts a pressing challenge in antimicrobial resistance (AMR), necessitating urgent intervention strategies due to the low success rate of new antibiotic development. Bacterial motility, beyond conventional antibiotic usage, significantly influences resistance evolution and ecological dynamics. Our recent study marks a breakthrough, revealing the unexplored ability of ultrafine gold nanosystems (UGNs) to inhibit bacterial resuscitation using a motile Escherichia coli (E.coli) K12 strain. We aim to deepen our comparative understanding of UGNs’ efficacy and resuscitation propensity against a non-motile E. coli K12 strain to assess the role of motility. Through UGN application, we identified heritable resistance in both strains, with motile strains exhibiting notably higher mutation rates. Resuscitation experiments unveiled faster recovery in motile strains, attributable to virulence factors, compared to non-motile strains. Additionally, our investigation into aggregation dynamics highlighted the role of protein-mediated aggregation in resistance development to nano-antimicrobials. Overall, the study reveals that the non-motile strains are more susceptible against UGNs, which shows promise in combating AMR.

Dissolving microneedles (DMNs) represent an innovative advancement in drug delivery and skincare technologies, offering significant advantages compared to traditional needles. This paper presents an overview of the historical evolution of microneedles and the rise of dissolving types, exploring their definition, concept, and diverse clinical applications such as vaccinations, drug delivery, and skincare treatments. Design and manufacturing considerations cover the materials employed, fabrication techniques, and methods for characterizing DMNs, focusing on aspects like mechanical strength, dissolution rate, and delivery efficiency. The mechanism of action section examines skin penetration mechanics, the process of microneedle dissolution, controlled release of active compounds, and considerations of biocompatibility and safety. Recent developments in DMNs encompass technological advancements, improved delivery systems, and updates on clinical trials and studies. Challenges and opportunities in scaling up production, overcoming market adoption barriers, and future research directions are discussed, aiming to address unmet medical needs and expand applications. In summary, DMNs have the potential to transform drug delivery and skincare treatments, with ongoing advancements aimed at tackling current challenges and unlocking new opportunities for enhanced healthcare outcomes.

Graphical Abstract

Cancer survivors undergo meticulous examinations, including regular magnetic resonance imaging (MRI) scans, to monitor the risk of disease recurrence. The use of magnetic iron nanoparticles (MNPs) enhances MRI accuracy. However, post-injection, MNPs exhibit a notable affinity for binding with proteins and biomolecules, forming a dynamic protein coating called a protein corona (CORONA). While there are reports of its elimination in the liver and kidney metabolism system, patients undergoing this method have shown symptoms of liver problems and related enzyme alterations. This study aims to discern whether the impact of MNPs on liver enzymes significantly contributes to liver damage. The investigation focuses on the effects of magnetic nanoparticles (MNPs) on selected enzymes, including alanine aminotransferase (ALT), aspartate transaminase (AST), α-amylase, and lipase. Employing 104 experiments over a central composite design (CCD), the study evaluates the effects of agents on MNP and enzyme structure, stability, and properties: enzyme assay, electron microscopy, and circular dichroism of secondary structure after interaction with MNPs. The study’s findings unveil the intricate relationship between MNPs and liver enzymes, providing valuable insights for clinical practices and refining the safety profile of MRI. This comprehensive exploration contributes to our understanding of potential implications and aids in optimizing the use of MNPs in medical imaging for cancer survivors.

Bulk micromachining is commonly used to fabricate microstructures such as deep cavities, through-holes, and microchannels in glass wafers, which have diverse applications in the areas of science and technology. The methods for glass bulk micromachining include mechanical, dry, and wet etching; among them, wet etching is widely used due to its multifaceted advantages. Masking layer plays an eminent role in wet etching. In the current study, Cr thin film combined with positive photoresist (AZ1512HS) is investigated as the masking layer to develop deep cavities in Borofloat glass wafers via wet etching route. Initially, DC magnetron sputtered Cr thin film is deposited at room temperature, 200 °C, and 400 °C, respectively, on three different glass wafers, followed by spin coating of photoresist on it. Photolithography process is used for patterning, and then selective etching of Cr is performed. Thereafter, wet etching of glass wafers is executed in 10% hydrofluoric acid (HF) solution. This work shows that the sustainability of the masking layer is highly dependent on the deposition temperature of Cr thin film, and the sustainability increases with the increase in the deposition temperature. The high temperature (400 °C) deposited Cr thin film along with photoresist exhibits superior sustainability as a masking layer, and it relatively provides a longer etch time of 380 min, excellent etch depth of  ~  245 µm with negligible surface defects and well-defined structures on glass wafer when etched in 10% HF solution.

As the dangers of volatile organic compounds (VOCs) and their potential as non-invasive diagnosis biomarkers have been reported, there has been a need for instrument capable of real-time and in-situ monitoring of multiple low-concentration VOCs in indoor air or human metabolites. A promising technology that can qualitatively and quantitatively analyze numerous VOCs as an alternative to conventional bench-top instruments is a micro-gas chromatography (µ-GC) system, which integrates three main components: a micro-gas preconcentrator, a µ-GC column, and a mini- or micro-detector fabricated using microelectromechanical system (MEMS) processes. This review covers the integration methods, features, and analysis capabilities of recently developed µ-GC systems and examines the materials, designs, and principles of the three main components. In addition, the challenging issues that must be addressed for the commercialization of this technology are discussed.