Nanometer Size Research Articles

The use of DES green solvents to produce electrocatalytically active Ni–Mo alloys. The insight into the role of surface chemistry and mechanism of HER

The Ni–Mo alloy coatings demonstrating high catalytic activity towards hydrogen evolution reaction were electrodeposited from a eutectic solvent composed of choline chloride and propylene glycol. The resulting alloys were characterized by spherical morphology and nanometric grain size (∼5–15 nm). XRD analysis indicated a gradient in phase composition with varying coating thickness, revealing that the coating surface was enriched with the Mo0.20Ni0.80 intermetallic compound. The obtained Ni–Mo alloy electrodes exhibited almost 3-times lower overpotential required to achieve a current density of 10 mA cm−2 compared to the reference Ni coating (−107 mV and −293 mV, respectively). The collected polarization and impedance data indicated that the enhancement in electrocatalytic activity was due to an increase in the real surface area of the alloy electrodes (Rf coefficient increased almost 9-times for Ni–Mo coatings compared to Ni coating). The electrocatalytic activity of the Ni–Mo alloy electrodes increased after successive CV cycles, attributed to changes in their surface composition (increase in current density by approx. 26% after 25 CV cycles).

Highly sensitivity and wide-range flexible humidity sensor based on LiCl/cellulose nanofiber membrane by one-step electrospinning

Cellulose is considered an ideal material for flexible electronic humidity sensors due to its green renewable nature, rich surface groups and strong hydrophilicity. However, the traditional cellulose-based humidity sensor cannot simultaneously have wide detection range, high sensitivity and fast response time, which seriously hinder their development and application. Here, an ultrathin Lithium chloride (LiCl)/cellulose nanofiber membrane as moisture sensitive materials was prepared by one-step electrospinning and used to assemble a high-performance humidity sensor. N, N-Dimethylacetamide/Lithium chloride (DMAc/LiCl) solvent system was used to dissolve the cellulose, and DMAc volatilized into the air while LiCl remained in the cellulose nanofibers during the electrospinning process. LiCl as a highly moisture-sensitive inorganic salt has strong hydrophilicity and enhances the moisture sensing detection limit of cellulose fiber (especially under low humidity conditions), thus giving the cellulose moisture sensor excellent sensitivity (up to 4191 %) and a wide detection range (5–98 % RH). The nanometer size of cellulose fibers, the extremely low thickness and large pores of cellulose membranes accelerate the mass exchange of moisture between the air and the membrane, thus giving cellulose humidity sensor a fast response/recovery time (99/110 s) and low hysteresis (2.9 %). Moreover, the performances of humidity sensors didn’t degrade even after being subjected to long-term application (>30 days), high/low temperatures (73.6/0.1 ℃) and thousands of bending cycles. The proposed LiCl/cellulose nanofiber humidity sensor brings innovative solutions for the design of cellulose based sensor with great potential for use in non-contact humidity detection, respiratory monitoring and sleep apnea detection applications.

Poly(L-lysine)-block-poly(ethylene glycol)-block-poly(L-lysine) triblock copolymers for the preparation of flower micelles and their irreversible hydrogel formation

ABSTRACT Poly(L-lysine)-block-poly(ethylene glycol)-block-poly(L-lysine) (PLys-block-PEG-block-PLys) triblock copolymers formed polyion complex (PIC) with poly(acrylic acid) (PAAc) or sodium poly(styrenesulfonate) (PSS), leading to the formation of flower micelle-type nanoparticles (NanoLys/PAAc or NanoLys/PSS) with tens of nanometers size in water at a polymer concentration of 10 mg/mL. The flower micelles exhibited irreversible temperature-driven sol-gel transitions at physiological ionic strength, even at low polymer concentrations such as 40 mg/mL, making them promising candidates for injectable hydrogel applications. Rheological studies showed that the chain length of PLys segments and the choice of polyanions significantly impacted irreversible hydrogel formation, with PSS being superior to PAAc for the formation. The incorporation of silica gel nanoparticles into the PIC flower micelles also resulted in irreversible gelation phenomena. The highest storage modulus exceeded 10 kPa after gelation, which is sufficient for practical applications. This study demonstrates the potential of these PIC-based hydrogels as biomaterials with tunable properties for biomedical applications.

Impact response of pseudoelastic nitinol

The response of polycrystalline nitinol with solely austenite structure was studied in three series of planar impact tests characterized by loading of the nitinol samples of 0.5–10 mm thickness by 1 mm thick aluminum impactor accelerated up to velocities of about 387, 429, and 567 m/s. In all the tests, the velocities of the free surfaces of the samples were monitored by a laser velocity interferometer. It was found that in all three test series, the amplitude of elastic precursor wave, being initially greater than 4 GPa, rapidly decays with the propagation distance down to ∼2.5 GPa, below which the decay is hindered by atomic clusters of the nanometer size. Based on the part of the velocity histories indicating the shock-induced austenite–martensite transformation, the initial, of about 2.5 × 103 s−1, and the maximum, up to 1 × 105 s−1, rates of the transformation were determined. As well, the impact stress slightly greater than 4 GPa was determined as that required for the onset of the B2 → B19′ transformation under shock loading. The unloading parts of the same velocity histories allowed a rough estimate of the fraction of the shock-transformed martensite and the elucidation of the virtually complete reversibility of the transformation.

Mechanoluminescent properties of transparent SrAl2B2O7:Eu3+ glass-ceramics

Mechanoluminescent materials possess the ability to generate luminescence when exposed to mechanical forces imparted by external stimuli. Traditionally, these materials have been predominantly comprised of phosphors, which, upon experiencing mechanical stress, absorb energy and subsequently emit photons, resulting in light emission. In our current investigation, aimed at discovering novel and highly efficient mechanoluminescent materials, we successfully synthesized a series of borate-based glass-ceramics featuring the SrAl2B2O7:Eu3+ crystal structure through a meticulous glass crystallization technique. X-ray diffraction (XRD) analysis confirmed the presence of the SrAl2B2O7 crystalline phase within the heat-treated samples. Transmission electron microscopy (TEM) observations revealed that grains, approximately 44 nanometers in size, were uniformly dispersed throughout the sample. Upon examining its fluorescence spectrum, it was evident that the material exhibited bright red fluorescence when excited by light at a wavelength of 395 nanometers. Measurements of the mechanoluminescent spectra further demonstrated that the SrAl2B2O7:Eu3+ glass-ceramics displayed a robust red mechanoluminescent effect. In conclusion, the red mechanoluminescent characteristics of SrAl2B2O7:Eu3+ glass-ceramics hold promising prospects for applications in high-resolution display imaging, stress sensing devices, optical data storage systems, and artificial skin technologies.

A meta-analysis of the effect of ultrasound activation parameters on phase-change nanodroplets in imaging and therapy

Phase-change nanodroplets (PCNDs) have been used in ultrasound imaging, targeted drug delivery, blood-brain-barrier (BBB) opening, sonothrombolysis and histotripsy for over a decade. For these ultrasound applications, PCNDs provide higher in vivo lifetime than microbubbles (MBs), the potential for extravasation inside tumour and on demand activation, which is the transition of the liquid-core of nanodroplets to gaseous microbubbles through acoustic droplet vaporisation (ADV). Operating above the ADV threshold can offer repeatable activation of PCNDs and the subsequent oscillation of acoustically activated PCNDs, which is advantageous in imaging and therapeutic applications. Efficient and repeatable activation of PCNDs require a good understanding of ultrasound parameters and nanodroplet composition for different biomedical applications. Therefore, this article presents a meta-analysis of the effect of ultrasound activation parameters on ADV for various PCNDs in different biomedical applications. About 7,500 articles were considered for this study, but only 45 articles were chosen and evaluated in the meta-analysis based on the following criteria: 1): activation parameters, including ultrasound frequency, peak negative pressure, transmit pulse length or duration have been clearly mentioned, 2), droplets range in nanometre size (<1 µm), 3), experiments are performed at a temperature of 37°C and 4) ADV threshold has been clearly mentioned and observations are not due to inertial cavitation (IC). From selected publications, we recorded the activation frequency (0.06–16 MHz), ultrasound pressure (0.18–14.9 MPa), activation pulse length (µs-ms range) and nanodroplet size for different types of perfluorocarbon PCNDs (C3F8, C4F10, C5F12 and C6F14) and evaluated the relation of these parameters to each other. Finally, a Root Mean Square (RMS)-like power metric, which is a combination of ultrasound peak negative pressure and square root of ultrasound pulse length, is proposed for identifying the ADV threshold behaviour instead of using pressure or mechanical index values.

Nanotechnological advancement for the treatment of neurodegenerative disorders

Neurodegenerative disorders are chronic and progressive conditions of the central nervous system. This review work focusses on some of the disorders like Alzheimer’s disease, Parkinson’s disease, Amyotrophic lateral sclerosis, and Huntington’s disease which are some of the most prevalent neurodegenerative disorders presenting a substantial challenge on the global health care system. These disorders are characterized by the loss of neurons and the formation of protein aggregates leading to cognitive and motor impairments. The treatment options are available but due to the complex pathophysiology of the disease and the intricate structure of the brain, effective concentrations of drugs are not delivered to brain. Here we discuss some of the recent strategies employed by scientists to enhance the drug delivery and drug targeting to the site of action that is brain for these disorders. Further, nanotechnology-based carrier systems have been discussed which are developed using different natural and synthetic polymers and lipid materials. Owing to many beneficial properties like nanometric size range, physicochemical properties and tunable surface-modifying features, nanocarriers serve as potential systems in the treatment of neurodegenerative diseases as they can easily cross the BBB and reach to the brain in effective concentration. This review article describes neurodegenerative disorders and the limitations associated with their conventional application. Different arrays of nanocarriers such as polymeric nanoparticles, liposomes, Solid Lipid Nanoparticles, Nanostructured Lipid Carriers, and Nanoemulsions have been extensively reviewed. To understand the nanomedicine market, the ongoing clinical trials for various nano-carriers employed to treat these disorders have been compiled and discussed.

Twenty Years of Graphene: From Pristine to Chemically Engineered Nano-Sized Flakes.

It is a celebratory moment for graphene! This year marks the 20th anniversary of the discovery of this amazing material by Geim and Novoselov. Curiously, it coincides with the century mark of graphite's layered structure discovery. Since the discovery of graphene with the promise that its outstanding properties would change the world, society often wonders where is graphene? In this context, their discoverers said in 2005, "despite the reigning optimism about graphene-based electronics, "graphenium" microprocessors are unlikely to appear for the next 20 years". Today, possibilities for graphene are endless! It can be used in electronics, photonics, fuel cells, energy storage, artificial intelligence, biomedicine, and even cultural heritage or sports. Additionally, the electronic properties of this material have been modified in fascinating ways. Bilayer graphene sheets have been found to be superconductive when twisted at a "magic angle", leading to a new and exciting field of research known as "moiré quantum materials" or "twistronics". Additionally, small graphene fragments with nanometer sizes undergo a quantum confinement effect of electrons, affording semiconductive materials with applications in optoelectronics. Organic synthesis allows the preparation of molecules with a graphene-like pattern with total control of the shape and size, exhibiting a big catalog of chiroptical and optoelectronic properties. This Perspective shows some of the fascinating milestones raised in the field of graphene-like materials from a chemical point of view, including functionalization strategies employed to chemically modify the topology and the properties of pristine graphene as well as the rising molecular graphenes.

Direct observation of nanometer size hydride precipitations in superconducting niobium

Superconducting niobium serves as a key enabling material for superconducting radio frequency (SRF) technology as well as quantum computing devices. Niobium has a high propensity for the uptake of hydrogen. At room temperature, hydrogen commonly occupies tetragonal sites in the Nb lattice as the metal (M)–gas (H) phase. When the temperature is decreased, however, a solid solution of Nb-H begins to precipitate. In this study, we show the first identified topographical features associated with nanometer-size hydride phase (Nb1−xHx) precipitates on the surface of the metallic superconducting niobium using cryogenic-atomic force microscopy (AFM). Further, high energy grazing incidence X-ray diffraction reveals information regarding the structure and stoichiometry of these precipitates. Finally, through time-of-flight secondary ion mass spectroscopy (ToF-SIMS), we locate atomic hydrogen sources near the top surface. This systematic study clarifies nanometer scale hydrides precipitated on the surface of the SRF Nb cavity that exhibit performance degradation at a high accelerating field regime.

Lipid-core nanocapsules containing simvastatin do not affect the biochemical and hematological indicators of toxicity in rats.

Our research group previously studied the effectiveness of lipid-core nanocapsules (LNC) containing simvastatin (SV-LNC) in treating cognitive impairment in rats. While our results were promising, we needed to evaluate the potential toxicity of the nanoparticles themselves. This study aimed to compare the biochemical and hematological parameters of adult Wistar rats receiving LNC or SV-LNC to those receiving low doses of simvastatin crystals dispersed in a saline solution over 45days. We discovered that LNC and SV-LNC, which are both nanometers in size with low polydispersity index, negative zeta potential, and high SV encapsulation efficacy, were not more toxic than SV crystals based on various biochemical markers of hepatic, pancreatic, renal, mineral, bony, alkaline phosphatase, glucose, and uric acid damage. Furthermore, LNC exhibited no toxicity for hematological parameters, including red and white blood cell counts. Based on this animal model of toxicological study, our findings suggest that long-term administration of LNC is a safe and promising nanocarrier.

Probing Abrikosov vortices in niobium with single nitrogen-vacancy centers in nanodiamonds

Abrikosov vortices play a fundamental role in the magnetic and electric properties of superconductors. The study of their pinning forces is essential to better understand the stability of vortex lattices, with the aim of increasing critical currents in superconductors. However, the study of vortices is challenging because of their nanometric sizes and the large variation in the pinning forces. In this Letter, we use a single nitrogen-vacancy center in a nanodiamond as a nanoscale magneto sensor to locally probe single vortices and their pinning effects in a thin niobium film. This simple, far-field optical approach also offers the possibility of manipulating a single spin with a single flux quantum.

Loading of metformin on C24 fullerene decorated with alkaline earth metals: Molecular computational assessment for drug delivery

The discovery of new drug carriers is one of the interesting topics in biological sciences, which in recent years have been combined with theoretical chemistry to accelerate this process by using materials around nanometers in size. We used a novel approach based on molecular thermodynamics for analysis of nanomaterials with advanced structures for drug delivery applications. Fullerene and its derivatives have been evaluated in many studies as various drug agents and obtainable results have been achieved. Here, by trapping Mg and Ca atoms in the C24 cage, the electronic properties are improved to better interact with the metformin molecule. The adsorption energies were estimated using the developed quantum modeling approach. Adsorption energies are -4.98 eV, -5.91 and -6.07 eV for pure C24, Mg@C24, and Ca@C24, respectively. MEP and DOS plots indicated that reduction of the HOMO-LUMO gaps in the considered clusters creates a stronger connection between the MF molecule and the nanocage, and the electron localization function identified that the interaction kind is covalent.

Antimicrobial activity of CuFe2O4 and CuFe2O4/ZnO: Squaring colorimetric and traditional microbiology assays with atomic force- and holotomography-microscopies

Intensive research efforts seek the discovery of efficient antimicrobial compounds to fight microbial resistance. Magnetic nanoparticles represent a promising option due to their multifunctional antimicrobial properties, as well as their versatility, stability, and the limited microbial resistance they generate. In this study, magnetic nanomaterials (MNMs) are synthesized using a microwave-activated solvothermal method. Characterization data indicate the crystalline nature (cubic spinel CuFe2O4 NMs), superparamagnetic behavior (MCF = 52 emu/g and MCF-ZnO = 29 emu/g) nanometric and regular size (spherical particles with a mean size of 7.4 ± 1.3 nm) of the MNMs. The antimicrobial activity of the as-prepared (naked) MNMs is moderate against bacteria, yeast, and fungal strains due to the aggregation of the MNMs in the exposure media. However, citrate-functionalized MNMs (CuFe2O4-Cit, CF-Cit) show enhanced antimicrobial activity, further increasing upon activation under a high-frequency magnetic field (magnetic hyperthermia). CF-Cit exerts stronger antibacterial activity towards S. aureus (MIC <25 μg/mL) than E. coli (MIC <50 μg/mL In addition, CuFe2O4-ZnO composites were synthesized and fully characterized. The MNMs under study exhibit efficient antifungal and anti-biofilm activity. Working towards the sustainable development of multifunctional (CuFe2O4 and CuFe2O4-ZnO) MNMs, their compatibility and bioactivity was evaluated using traditional assays and advanced microscopy techniques (Atomic Force Microscopy-AFM and Holotomographic Microscopy -HTM). Because of their chemical composition, the MNMs under study lixiviate transition metal ions to the exposure media, interfering with traditional colorimetric assays used to evaluate the bioactivity of the MNMs (antimicrobial, biocompatibility). Thus, AFM and HTM studies render complementary information during the interpretation of the bioactivity mechanisms exhibited by the MNMs.

Indefinitely flat rotation curves from Mpc sized charged cocoons

Weak lensing exhibits that rotation curves of isolated galaxies remain flat up to Mpc scale (Mistele T. et al. Astrophys. J. Lett.9692024L3). Recently we proposed that dark matter is a combination of electrostatic and vacuum energy in standard physics. In this theory, isolated galaxies may be embedded in “charged cocoons”, spheres with charge density. The related circular rotation curves decay at the Mpc scale. The analytic solution is extended to the early Universe. A peak in the cosmic microwave background spectrum is expected at the arcsec scale. The induced nanometer size of the cocoons at the Big Bang makes the initial state inhomogeneous.

Crystallization behavior and thermal properties of octa-phenyl-substituted silsesquioxane-modified polylactide (PLA)

This study aims to understand the effects of adding octa-phenyl-substituted silsesquioxane (phSQ) on the crystallization process and thermal stability of polylactide (PLA). Nowadays, PLA is the most industrially used compostable polymer, but its uses are limited by its low crystallization and thermal degradation during processing. The possibility of introducing functionalized silsesquioxanes (SQs) to improve thermal stability and increase its crystallinity and ductility in a controlled way is desirable. The nanometric size of the Si-O-Si cage, coupled with the influence of the functional groups attached to its structure, enables it to function as a heterogeneous nucleating agent. In this work, a specially synthesized octa-phenyl-substituted SQ (phSQ) was added to the PLA in 0.5–5 wt%. Crystallization in non-isothermal and isothermal conditions was conducted and monitored using differential scanning calorimetry (DSC); the course of the spherulite formation under identical conditions to DSC was also assessed using optical microscopy in polarized light. The results showed that phSQ increases the degree of crystallinity of PLA by introducing additional sites of heterogeneous nucleation but does not increase the spherulite growth coefficient. Additionally, the analysis of thermal properties indicates that the presence of phSQ could not have a positive impact on thermal stability. The agglomeration of the nanometric particles and changes in the main structural features of the polymeric matrix could be present in the samples, affecting the obtained results.Graphical abstract

Nano Revolution: Harnessing Nanoparticles to Combat Antibiotic-resistant Bacterial Infections.

Nanoparticles, defined as particles ranging from 1 to 100 nanometers in size, are revolutionizing the approach to combating bacterial infections amid a backdrop of escalating antibiotic resistance. Bacterial infections remain a formidable global health challenge, causing millions of deaths annually and encompassing a spectrum from common illnesses like Strep throat to severe diseases such as tuberculosis and pneumonia. The misuse of antibiotics has precipitated the rise of resistant strains like methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant Mycobacterium tuberculosis (MDR-TB), and carbapenem-resistant Enterobacteriaceae (CRE), underscoring the critical need for innovative therapeutic strategies. Nanotechnology offers a promising avenue in this crisis. Nanoparticles possess unique physical and chemical properties that distinguish them from traditional antibiotics. Their high surface area to volume ratio, ability to be functionalized with various molecules, and distinctive optical, electronic, and magnetic characteristics enable them to exert potent antibacterial effects. Mechanisms include physical disruption of bacterial membranes, generation of Reactive Oxygen Species (ROS), and release of metal ions that disrupt bacterial metabolism. Moreover, nanoparticles penetrate biofilms and bacterial cell walls more effectively than conventional antibiotics and can be precisely targeted to minimize off-target effects. Crucially, nanoparticles mitigate the development of bacterial resistance by leveraging multiple simultaneous mechanisms of action, which make it challenging for bacteria to adapt through single genetic mutations. As research advances, nanotechnology holds immense promise in transforming antibacterial treatments, offering effective solutions that address current infections and combat antibiotic resistance globally. This review provides a comprehensive overview of nanoparticle applications in antibacterial therapies, highlighting their mechanisms, advantages over antibiotics, and future directions in healthcare innovation.

Multifunctional hybrid films made from CoT3OTx4 and CoFeT2OT4 nanoparticles inside a poly 3-hydroxybutyrate matrix and study of their impact in methyl orange photodegradation.

This work aims to produce hybrid materials with potential applications in dye photodegradation. Therefore, hybrid films were obtained by incorporating cobalt (II, III) oxide (Co3O4) or cobalt ferrite (CoFe2O4) nanoparticles (NPs) with 18 ± 1.6 nm and 26 ± 1.3 nm, respectively, into a poly 3-hydroxybutyrate (P3HB) polymeric matrix. The Co3O4@P3HB and CoFe2O4@P3HB hybrid films were fabricated by solvent casting in a ratio of 85 mg to 15 mg (P3HB-NPs). Different spectroscopic and microscopy techniques characterized the Co3O4 and CoFe2O4 NPs and the P3HB, Co3O4@P3HB and CoFe2O4@P3HB films. The optical band gap for Co3O4 and CoFe2O4 NPs was estimated from their diffuse reflectance spectra (DRS) around 2.5 eV. X-ray diffraction (XRD) of the hybrid films revealed that the nanometric sizes of the Co3O4 and CoFe2O4 nanoparticles incorporated into the P3HB are preserved. The magnetic hysteresis curve of CoFe2O4 nanoparticles and CoFe2O4@P3HB film showed a ferromagnetic behaviour at 300 K. Transmission electron microscopy (TEM) confirmed the formation of nanocrystals, and scanning electron microscopy (SEM) provided evidence for the successful incorporation of the NPs into the P3HB matrix. The surface roughness and hydrophilicity of the hybrid films are increased compared to the P3HB film. The impact of the nanoparticles and the hybrid films on the photodegradation of methyl orange (MO) in its acidic form was studied. The photodegradation tests were carried out by direct sunlight exposure. The CoFe2O4@P3HB hybrid film achieved 85% photodegradation efficiency of a methyl orange solution of 20 ppm after 15 minutes of exposure to sunlight. After 30 minutes of exposure to sunlight, the nanoparticles and the hybrid films reached about 90% of the MO degradation. The results suggest that combining nanoparticles with the polymer significantly enhances photodegradation compared to isolated nanoparticles.

Macrophage Membrane-Coated Nanoparticles for the Delivery of Natamycin Exhibit Increased Antifungal and Anti-Inflammatory Activities in Fungal Keratitis.

This study aims to explore the efficacy and safety of macrophage membrane-coated nanoparticles for the delivery of natamycin (NAT) in the therapy of fungal keratitis (FK). Macrophage membranes were isolated and identified by immunofluorescence staining (IFS). NAT was encapsulated into poly(lactic-co-glycolic acid) (PLGA). Fungal stimulated macrophage membranes (M1) or unstimulated membranes (M) were separately mixed and sonicated with PLGA nanoparticles. The biocompatible nanoparticles (PLGA-NAT, PLGA-NAT@M, and PLGA-NAT@M1) were characterized with zeta-sizer analysis, transmission electron microscopy (TEM), and Western blot. Drug encapsulation and loading efficiency and the release of NAT in the nanoparticles were detected by ultraviolet spectrophotometry. The cytotoxicity, ocular surface toxicity and irritability, and systemic safety of nanoparticles with different concentrations were assessed. In vitro, we examined the antifungal properties of the nanoparticles. The eye surface retention time, drug release, and curative effects on FK were evaluated in vitro and in vivo. IFS results showed the separation of the macrophage membrane and nucleus. The prepared nanoparticles had a typical "core-shell" structure and uniform nanometer size, and the membrane proteins were retained on the membrane allowing to exert functional effects of macrophage. The loading efficiencies of PLGA-NAT@M and PLGA-NAT@M1 were 7.6 and 6.7%, respectively. The encapsulation efficiencies of PLGA-NAT@M and PLGA-NAT@M1 were 51.2 and 41.5%, respectively. PLGA-NAT@M and PLGA-NAT@M1 could gradually release NAT and reduce the clearance of the ocular surface. Macrophage membranes enhanced the antifungal activity of PLGA-NAT. Furthermore, the membrane coated with macrophage increased the biocompatibility and decreased the corneal toxicity of nanoparticles. In vivo, PLGA-NAT@M1 significantly alleviated the severity of FK. In vitro, PLGA@M and PLGA@M1 reduced the protein levels of inflammatory cytokines after fungal stimulation. The prepared PLGA-NAT@M1 has good physical properties and biosafety. It could evade ocular surface clearance, release NAT gradually, and achieve high antifungal and anti-inflammatory efficiencies to FK. Macrophage membrane-coated nanoparticles clinically have high application potential to the treatment of FK.

Emerging Cationic Nanovaccines.

Cationic vaccines of nanometric sizes can directly perform the delivery of antigen(s) and immunomodulator(s) to dendritic cells in the lymph nodes. The positively charged nanovaccines are taken up by antigen-presenting cells (APCs) of the lymphatic system often originating the cellular immunological defense required to fight intracellular microbial infections and the proliferation of cancers. Cationic molecules imparting the positive charges to nanovaccines exhibit a dose-dependent toxicity which needs to be systematically addressed. Against the coronavirus, mRNA cationic nanovaccines evolved rapidly. Nowadays cationic nanovaccines have been formulated against several infections with the advantage of cationic compounds granting protection of nucleic acids in vivo against biodegradation by nucleases. Up to the threshold concentration of cationic molecules for nanovaccine delivery, cationic nanovaccines perform well eliciting the desired Th 1 improved immune response in the absence of cytotoxicity. A second strategy in the literature involves dilution of cationic components in biocompatible polymeric matrixes. Polymeric nanoparticles incorporating cationic molecules at reduced concentrations for the cationic component often result in an absence of toxic effects. The progress in vaccinology against cancer involves in situ designs for cationic nanovaccines. The lysis of transformed cancer cells releases several tumoral antigens, which in the presence of cationic nanoadjuvants can be systemically presented for the prevention of metastatic cancer. In addition, these local cationic nanovaccines allow immunotherapeutic tumor treatment.

Scalable Metal–Organic Chemical Vapor Deposition of High Quality PtSe2

AbstractPlatinum diselenide (PtSe2), a 2D noble metal dichalcogenide, has recently received significant attention due to its outstanding properties. It undergoes a semimetal to semiconductor transition when thinned, offers a bandgap in the infrared range, and exhibits excellent stability in ambient conditions. These properties make it a prime active material in optoelectronic and chemical sensing devices. However, there is a high demand for a synthesis method that can produce large‐scale and reliable high‐quality PtSe2. In this study, the growth of PtSe2 is presented by metal–organic vapor deposition on a variety of substrates. Comprehensive Raman, X‐ray photoelectron, and X‐ray diffraction spectroscopy, as well as scanning tunneling microscopy characterization reveals the high quality of the deposited PtSe2. Domains within the films are found to be up to several hundreds of nanometers in size, and their highly ordered crystalline structure is evident from atomic‐scale measurements. Electrical characterization demonstrates improved conductivity relative to conventional synthesis methods. This study provides fundamental guidance for the scalable synthesis and implementation of high quality PtSe2 layers with controllable thickness, offering a key requirement for the implementation of PtSe2 in future applications.