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In-situ polymer capping of cesium lead bromide (CsPbBr3) nanocrystals with polymethyl acrylate is an effective approach to improve the colloidal stability in the polar medium and thus extends their use in photocatalysis. The photoinduced electron transfer properties of polymethyl acrylate (PMA)-capped CsPbBr3 nanocrystals have been probed using surface-bound viologen molecules with different alkyl chains as electron acceptors. The apparent association constant (Kapp) obtained for the binding of viologen molecules with PMA-capped CsPbBr3 was 2.3 × 107 M−1, which is an order of magnitude greater than that obtained with oleic acid/oleylamine-capped CsPbBr3. Although the length of the alkyl chain of the viologen molecule did not show any impact on the electron transfer rate constant, it influenced the charge separation efficiency and net electron transfer quantum yield. Viologen moieties with a shorter alkyl chain length exhibited a charge separation efficiency of 72% compared with 50% for the longer chain alkyl chain length viologens. Implications of polymer-capped CsPbBr3 perovskite nanocrystals for carrying out photocatalytic reduction in the polar medium are discussed. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have gained remarkable attention as therapeutic agents since the appearance of nanotechnology. This study aims to assess the protective impact of chitosan‐silver nanoparticles (CS‐AgNPs) against DEN‐induced hepatocellular injury by regulation of Wnt/β‐Catenin and apoptosis signaling pathways in rats. CS‐AgNPs solutions were prepared by mixing different concentrations of chitosan and silver nitrate, and then subjected to gamma radiation at 20 kGy. The formation of CS‐AgNPs could be observed by naked eyes from the colour change from light yellow to reddish‐brown, and confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Stability measurements confirmed that the prepared Cs‐AgNPs are highly stable for around 8 weeks. A crystal violet cytotoxicity assay of CS‐AgNPs has been detected in vitro on HepG2 hepatocellular carcinoma cell lines. The obtained results confirmed the selective influence of CS‐AgNPs on the HCC cell line in a time and dose dependent manner. Diethylnitrosamine (DEN) induced a marked increase in the expressions of Wnt, β‐Catenin, STAT3, MMP9, and Bcl‐2 with a significant decrease in the expression of BAX, p53, and P21. Additionally, DEN significantly decreased the levels of Cytc and TPTH while significantly increased the levels of COX‐2, PGE2, TGF‐1, AFP, and liver enzyme activity. The role of CS‐AgNPs is documented in diminishing the expressions of Wnt, β‐Catenin, STAT3, MMP9, and Bcl‐2. Also, CS‐AgNPs induced the decrease in the levels of COX‐2, PGE2, TGF‐1, AFP and liver enzyme activity accompanied by increased apoptosis. These results concluded that CS‐AgNPs might be a promising drug designed for treating liver diseases. [ABSTRACT FROM AUTHOR]

[Display omitted] Imogolite nanotubes (INTs) are unique anisometric particles with monodisperse nanometric diameters. Aluminogermanate double-walled INTs (Ge-DWINTs) are obtained with variable aspect ratios by controlling the synthesis conditions. It thus appears as an interesting model system to investigate how aspect ratio and ionic valence influence the colloidal behavior of highly anisometric rods. The nanotubes were synthesized by hydrothermal treatment for 5 or 20 days to modify the aspect ratio while the electrostatic interactions were investigated by comparing the colloidal stability in symmetric and asymmetric electrolytes. The phase behavior and their related microstructure were determined by optical observations and small-angle X-ray scattering measurements, coupled with interparticle distance modelling. We revealed that colloidal suspensions of Ge-DWINTs prepared in NaCl are guided by repulsive double layer forces, undergoing different liquid crystal phase transitions before stiffen into a glass-like state. We found that the microstructure can be rationalized by taking into account the anisometric nature of the particles. By contrast, dispersions prepared with asymmetric electrolytes are governed by strong attractive forces and thus form space-filling gels containing large nanotubes aggregates. [ABSTRACT FROM AUTHOR]

The cell membrane not only serves as the boundary between the cell's interior and the external environment but also plays a crucial role in regulating fundamental cellular behaviours. Interfacial membranization of membraneless coacervates, formed through liquid-liquid phase separation (LLPS), represents a reliable approach to constructing hierarchical cell-like entities known as protocells. In this study, we demonstrate the capability to modulate the interfacial membrane fluidity and thickness of dextran-bound coacervate protocells by adjusting the molecular weight of dextran or utilizing dextranase-catalyzed hydrolysis. This modulation allows for rational control over colloidal stability, interfacial molecular transport and cell-protocell interactions. Our work opens a new avenue for surface engineering of coacervate protocells, enabling the establishment of cell-mimicking structures and behaviours. Membranization of coacervate microdroplets can stabilize coacervates and enable the construction of hierarchical protocells by using various interfacial layers. Here, the authors demonstrate the modulation of interfacial membrane fluidity and thickness of dextran-bound coacervate protocells by adjusting the molecular weight of dextran or through enzymatic hydrolysis, achieving control over colloidal stability, interfacial molecular transport and cell-protocell interactions. [ABSTRACT FROM AUTHOR]

This article presents new research on producing lignin nanoparticles (LNPs) using the antisolvent nanoprecipitation method. Acetone (90%) served as the lignin solvent and water (100%) as the antisolvent, using five types of lignins from various sources. Comprehensive characterization techniques, including NMR, GPC, FTIR, TEM, and DLS, were employed to assess both lignin and LNP properties. The antioxidant activity of the LNPs was evaluated as well. The results demonstrated the successful formation of spherical nanoparticles below 100 nm with initial lignin concentrations of 1 and 2%w/v. The study highlighted the crucial role of lignin purity in LNP formation and colloidal stability, noting that residual carbohydrates adversely affect efficiency. This method offers a straightforward, environmentally friendly approach using cost-effective solvents, applicable to diverse lignin sources. The innovation of this study lies in its demonstration of a cost-effective and eco-friendly method to produce stable, nanometric-sized spherical LNPs. These LNPs have significant potential as reinforcement materials due to their reinforcing capability, hydrophilicity, and UV absorption. This work underscores the importance of starting material purity for optimizing the process and achieving the desired nanometric dimensions, marking a pioneering advancement in lignin-based nanomaterials. [ABSTRACT FROM AUTHOR]

Origins research currently rests on a vitalistic foundation and requires reconceptualization. From a cellular perspective, prokaryotic cells grow and divide in stable, colloidal processes, throughout which the cytoplasm remains crowded (concentrated) with closely interacting proteins and nucleic acids. Their functional stability is ensured by repulsive and attractive non‐covalent forces, especially van der Waals forces, screened electrostatic forces, and hydrogen bonding (hydration and the hydrophobic effect). On average, biomacromolecules are crowded at above 15% volume fraction, surrounded by up to 3 nm layer of aqueous electrolyte at ionic strength above 0.01 molar; they are energized by biochemical reactions coupled to nutrient environments. During cellular growth, non‐covalent molecular forces and biochemical reactions stabilize the cytoplasm as a two‐phase, colloidal system comprising vectorially structured cytogel and dilute cytosol. From a geochemical perspective, Earth's rotation kept prebiotic molecules in continuous cyclic disequilibria in Usiglio‐type intertidal pools, rich in potassium and magnesium ions, the last cations to precipitate from evaporatig seawater. These ions impart biochemical functionality to extant proteins and RNAs. The prebiotic molecules were repeatedly purified by phase separation in response to tidal drying and rewetting; they were chemically evolving as briny, carbonaceous inclusions in tidal sediments until the crowding transition allowed chemical evolution to proceeed toward Woesian progenotes, the Last Universal Common Ancestors (LUCAs) and the first prokaryotes. These cellular and geochemical processes are summarized as a jigsaw puzzle of the emerging and evolving prokaryotes. Their unavoidable cyclic fusions and rehydrations along Archaean coastlines initiated the emergence of complex Precambrian eukaryotes. [ABSTRACT FROM AUTHOR]

Summary: Psyllium husk has attracted increasing interest in food applications due to its well‐known health benefits. Size reduction is an important mechanical operation used to tailor the functional properties of materials. In this study, the physicochemical properties and colloidal stability of the PHPs with different sizes were characterised by particle size distribution, zeta potential, Fourier transform infrared (FT‐IR) and X‐ray photoelectron spectroscopy (XPS). Furthermore, the size effects of psyllium husk on surimi gel properties were investigated in terms of the gel strength, water‐holding capacity (WHC) and water distribution. The results found that milling changed the monosaccharide composition and increased the diffraction intensity of psyllium husk powder (PHP) without disrupting the β‐glycosidic linkages. Furthermore, the XPS results suggested that smaller samples showed more exposed surface functional groups. The PHP3 group with average size of d (0.5) = 259.50 μm exhibited the highest absolute zeta potential. The viscosity and zeta potential of PHP correlated positively and negatively with the gel strength of surimi, respectively. Moreover, the micronized PHP also contributed to the increase in immobilised water content and uniform water distribution in surimi gels. The high viscosity and colloidal stability of psyllium husk (PHP3 group) contributed to the improved mechanical properties of surimi gels. This work provides a valuable reference for the potential use of psyllium husk in quality improvement of surimi products through size control. [ABSTRACT FROM AUTHOR]

Curcumin (CUR) is a natural compound extracted from turmeric (Curcuma longa), which has been reported to be a promising anti-cancer drug in various cancers. However, poor water solubility and low bioavailability posed a challenge for clinical application of curcumin. In this work, four CUR prodrugs, namely PEG4000-SS-CUR, PEG1500-SS-CUR, PEG4000-SeSe-CUR and PEG1500-SeSe-CUR were synthesized. These four CUR prodrugs have high CUR loading content and can self-assemble into spherical nanoparticles (NPs) with particle size of 90–190 nm in aqueous solution. The four CUR prodrug NPs exhibit good colloidal stability in PBS buffer and promoted drug release in response to GSH. Due to the enhanced water solubility, the four CUR prodrug NPs all exhibit reduced cellular uptake amount as compared to CUR in in vitro cellular uptake study. The four CUR prodrug NPs exhibit similar cytotoxicity against 22Rv1 cells as compared to free CUR while PEG4000-SeSe-CUR NPs exhibit the highest cytotoxicity and induce the highest cell apoptosis ratio against 4T1 cells in in vitro antitumor effect study. PEG4000-SeSe-CUR NPs developed in this work were proven to be an effective nanoformulation of CUR against 4T1 cells. [ABSTRACT FROM AUTHOR]

This work presents for the first time one-step ultrafast (precursor-free) synthesis of 1D MnFe 2 O 4 (MFO) nanorods and soft magnetic colloidal nanoparticles (NPs) using microwave-assisted hydrothermal (MAH) methods, with or without citric acid (CA) as a surfactant (in situ synthesis), respectively. The mechanism of growth of spinel MFO nanostructures during the MAH synthesis was studied by varying synthesis duration (3–6 h) and temperature (180–200 °C). An increase in both the duration and temperature improved the purity of the samples, up to 97%. On the other hand, a temperature increase by 20 °C notably shortened the formation time of MFO nanorods, which have an average diameter and length of less than 20 nm and 350 nm, respectively, as observed at 200 °C after 6 h. All the fabricated MFO NPs with spherical and rod-like morphologies manifested high saturation magnetization in the range of 54–64 emu/g. The chelation of lattice metal ions by CA resulted in the formation of a stable colloid comprising 100% pure spinel MFO NPs with a size of ≤32 ± 10 nm (mean ± SD) and featuring very soft magnetic properties. This colloid was generated by the MAH synthesis at 175 °C within 30 min. Notably, an increase in synthesis duration from 30 min to 3 h diminished MFO phase purity from 100% to 52% and saturation magnetization from 43.4 ± 0.7 to 33.9 ± 2.0 emu/g for CA-functionalized MFO NPs owing to CA degradation increasing during the in situ MAH synthesis with longer duration. This study indicates good potential of ultrafast MAH synthesis for the development of 1D magnetic spinel nanostructures with controllable morphology, size, magnetic properties, and colloidal stability, thereby offering a wide range of applications within the fields of adsorption, catalysis, electronics, and biomedicine. [ABSTRACT FROM AUTHOR]

A cell with a superior performance and durable catalyst layer can be achieved by optimizing the catalyst ink formulation. A typical commercial catalyst layer for both proton exchange membrane fuel cells and water electrolyzers is prepared via dispersion-based catalyst inks. Generally, ink dispersion composed of supported catalyst, ionomer, and solvent. The ink formulation governs physical properties such as homogeneity, the interaction between ink components, ability to store the ink (shelf-life) for an extended period and reproducibility. This is pivotal in optimizing the catalyst ink formulation for high performance, extended durability, and reproducibility, particularly in large-scale industrial manufacturing in polymer electrolyte membrane (PEM) fuel cells and electrolyzers. Despite the substantial progress on synthesis of different catalysts and ionomers, there is a limited understanding of the colloidal stability of the catalyst ink. The novelty of this review is to provide a guide to understand the importance of catalyst ink dispersion stability for manufacturing MEAs at scale-up level. This is addressed through targeting fundamental interaction behavior and physical properties of the ink materials. Further, this review covers the effect of particle surface, effect of solvent composition, and the effect of ionomer concentration that ensures a homogenized catalyst ink. In addition, this review covers the influence of different dispersion methodologies and the relevant characterization techniques for better understanding the dispersion stability. • Reviewed the importance of ink constituents for PEM fuel cell and electrolyzer. • Elucidated the causation of ink agglomeration and the impact on the cell behavior. • Discussed the importance of ionomer adsorption on catalyst ink stability. • Reviewed the characterizing techniques to study the catalyst ink stability. [ABSTRACT FROM AUTHOR]

X-ray luminescent nanoparticles have gained significant attention as promising tools for implementing multimodal imaging and radiation-based treatments in theragnostics. The intricate comprehension of their properties and the underlying mechanisms driving the conversion of X-rays into light is critical for their success in various applications. LaPO 4 nanoparticles doped with various individual luminescence centers, gadolinium (Gd3+), europium (Eu3+), dysprosium (Dy3+), and terbium (Tb3+), were produced via co-precipitation and investigated for their behavior upon X-ray excitation using energies of up to 225 kV. These materials evidenced a radioluminescent response dependent on the dopant concentrations, with emission lines from 300 to 700 nm, providing insights into the luminescence quenching effect in these structures. The luminescent characteristics of the nanoparticles were studied under continuous irradiation, evidencing the materials' ability to withstand high absorbed doses and preserve their properties. Furthermore, the influence of dopant concentrations on crystallite size and the dependence of luminescence on thermal treatments was investigated. The assessment of nanoparticle stability in aqueous suspension was evaluated over a broad pH range, revealing a tendency of the LaPO 4 surface to selectively interact with electropositive species. This insight enhances our comprehension of the colloidal stability of the material, positioning it for extended applications and in vitro evaluations, along with further surface functionalization. [ABSTRACT FROM AUTHOR]

This paper investigates the effect of three different alkalis, namely ammonia (NH4OH), ethylenediamine (EDA), and tetrabutylammonium hydroxide (TBAOH) on the stability of colloidal silica, with pH controlled within the range of 8–11. As a result, NH4OH greatly promotes the stability of silica sol at first due to the strong solvation ability of NH4+ and then the stability begins to decrease because the electric double layer of silica is compressed. The addition of EDA into silica system leads to a reduction in the stability evidently followed by a slight increase, which can be explained by the cationic bridging effect of the ethylenediammonium cations. Meanwhile, the effect of TBAOH on silica dispersion is analogous to EDA, mainly caused by the hydrophobic and steric effects. The abovementioned relevant stability mechanisms are involved in non-DLVO theory. [ABSTRACT FROM AUTHOR]

Surface enhanced resonance Raman (SERS) is a powerful optical technique, which can help enhance the sensitivity of Raman spectroscopy aided by noble metal nanoparticles (NPs). However, current SERS‐NPs are often suboptimal, which can aggregate under physiological conditions with much reduced SERS enhancement. Herein, a robust one‐pot method has been developed to synthesize SERS‐NPs with more uniform core diameters of 50 nm, which is applicable to both non‐resonant and resonant Raman dyes. The resulting SERS‐NPs are colloidally stable and bright, enabling NP detection with low‐femtomolar sensitivity. An algorithm has been established, which can accurately unmix multiple types of SERS‐NPs enabling potential multiplex detection. Furthermore, a new liposome‐based approach has been developed to install a targeting carbohydrate ligand, i.e., hyaluronan, onto the SERS‐NPs bestowing significantly enhanced binding affinity to its biological receptor CD44 overexpressed on tumor cell surface. The liposomal hyaluronan (HA)‐SERS‐NPs enabled visualization of spontaneously developed breast cancer in mice in real time guiding complete surgical removal of the tumor, highlighting the translational potential of these new glyco‐SERS‐NPs. [ABSTRACT FROM AUTHOR]

This study aimed to develop and implement a nanotechnology-based alternative to traditional tracers used in the oil and gas industry for assessing interwell connectivity. A simple and rapid hydrothermal protocol for synthesizing carbon quantum dots (CQDs) using agroindustry waste was implemented. Three commercial CQDs were employed (CQDblue, CQDgreen, and CQDred); the fourth was synthesized from orange peel (CQDop). The CQDs from waste and other commercials with spherical morphology, nanometric sizes less than 11 nm in diameter, and surface roughness less than 3.1 nm were used. These tracers demonstrated high colloidal stability with a negative zeta potential, containing carbonyl-type chemical groups and unsaturations in aromatic structures that influenced their optical behavior. All materials presented high colloidal stability with negative values of charge z potential between −17.8 and −49.1. Additionally, individual quantification of these tracers is feasible even in scenarios where multiple CQDs are present in the effluent with a maximum percentage of interference of 15.5% for CQDop in the presence of the other three nanotracers. The CQDs were injected into the field once the technology was insured under laboratory conditions. Monitoring the effluents allowed the determination of connectivity for five first-line producer wells. This study enables the application of CQDs in the industry, particularly in fields where the arrangement of injector and producer wells is intricate, requiring the use of multiple tracers for a comprehensive description of the system. [ABSTRACT FROM AUTHOR]

Quantum dot light‐emitting diodes (QD‐LEDs) have received significant attention as a next‐generation display technology aimed at large‐size panel production with lower manufacturing costs and excellent picture quality. Here, we demonstrated all‐inkjet‐printed 12.4‐in. full‐color QD‐LED display with the 182‐ppi resolution. The efficiency and lifetime of inkjet‐printed QD‐LEDs were improved through the ligand exchange of Cd‐free quantum dots (QDs), red and green InP and blue ZnSeTe QDs, and optimal control of ink formulation. Dual ligands enhanced colloidal stability and carrier transport properties. The introduction of appropriate additives in the mixed solvent system improved the inkjet processibility and the morphology of inkjet‐printed layers. [ABSTRACT FROM AUTHOR]

In this work, a highly efficient photosensitive quantum dot (QD) system was designed. The optimized photosensitive QD system had high photoluminescence quantum yield and colloidal stability. By direct photolithography, RGB pixel arrays with a single sub‐pixel size of 39 μm × 5 μm were successfully prepared. Further, the full‐color QLED device was realized. There were no residual QD emission peaks from neighboring sub‐pixels observed in the electroluminescence spectra. Experience on the full‐color QLED device guided the successful preparation of a 4.7‐inch 650 PPI active matrix QLED prototype. The active matrix QLED prototype could display clear and complete pictures. The color gamut reached 85% of the BT2020 standard. This is the first active matrix QLED prototype prepared with a record‐high resolution by direct photolithography, which promoted the development of QLED display technology. [ABSTRACT FROM AUTHOR]

The effects of shear degradation on the microstructures and properties of grease were investigated using a planetary ball mill to simulate a bearing shear zone on grease. The microstructure, cone penetration, colloidal stability, rheological properties noise properties, water washout characteristics and low-temperature torque of lithium grease were characterized. The microstructure of the initial lithium grease is a three-dimensional network structure formed by the uniform fibers. The entanglement level is high. As the ball milling shear time increases, the network structure of lithium grease is destroyed and the fibers are sheared to become short. Eventually all of them become short fibers. The performance test of lithium grease reveal that the cone penetration increases, colloidal stability, structural strength, noise properties, water washout characteristics of lithium grease gradually decreased with the increase of ball milling shear time. Additionally, the low-temperature starting torque and running torque of the grease gradually decrease. This phenomenon occurs due to changes in the microstructure of lithium grease. The shear degradation of lithium grease was mainly divided into two stages: the rapid stage was the destruction of the thickener network structure and the fibers being shortened by shearing. The slow stage was the process in which short fibers were sheared into shorter fibers. [ABSTRACT FROM AUTHOR]

The development of lipid nanoparticle (LNP) based therapeutics for delivery of RNA has triggered the advance of new strategies for formulation, such as high throughput microfluidics for precise mixing of components into well-defined particles. In this study, we have characterised the structure of LNPs throughout the formulation process using in situ small angle x-ray scattering in the microfluidic chip, then by sampling in the subsequent dialysis process. The final formulation was investigated with small angle x-ray (SAXS) and neutron (SANS) scattering, dynamic light scattering (DLS) and cryo-TEM. The effect on structure was investigated for LNPs with a benchmark lipid composition and containing different cargos: calf thymus DNA (DNA) and two model mRNAs, polyadenylic acid (polyA) and polyuridylic acid (polyU). The LNP structure evolved during mixing in the microfluidic channel, however was only fully developed during the dialysis. The colloidal stability of the final formulation was affected by the type of incorporated nucleic acids (NAs) and decreased with the degree of base-pairing, as polyU induced extensive particle aggregation. The main NA LNP peak in the SAXS data for the final formulation were similar, with the repeat distance increasing from polyU

The aim of this study was to characterize and compare the zeta potential of particles sensitive to external thermal stimuli. Poly N-(isopropyl) acrylamide (PNIPA) was selected as the thermosensitive polymer with a volume phase transition temperature (VPTT) between 32 and 33 °C. The hydrodynamic diameter (DH) of the nanoparticles was measured by dynamic light scattering. Zeta potential (ZP) measurements were performed with the same instrument used for DH measurements. ZP measurements allow the prediction of the stability of colloidal systems in aqueous solutions. These measurements were combined with a pH study before and after the purification process of the particles. The ZP was measured to determine the electrostatic interactions between the particles, which can lead to particle aggregation and decrease their colloidal stability. The effect of the composition of the synthesized particles on the ZP was assessed. One of the most important factors influencing ZP is pH, especially in aqueous solutions. The initiator did not significantly affect the DH of the particles, but it did significantly affect the ZP. The synthesized particles were subjected to a visible radiation absorption study in the selected temperature range to determine the VPTT. [ABSTRACT FROM AUTHOR]

Liposomal amphotericin B (Ambisome®) is the gold standard for the treatment and prevention of fungal infections both in the adult and pediatric populations. The lyophilized dosage form has to be reconstituted and diluted by hospital staff, but its management can be challenging due to the spontaneous tendency of amphotericin B to form aggregates with different biological activity. In this study, the colloidal stability of the liposomes and the chemical stability of amphotericin B were investigated over time at storage conditions. Three liposomal formulations of amphotericin B at 4.0 mg/mL, 2.0 mg/mL, and 0.2 mg/mL were prepared and assayed for changes regarding the dimensional distribution, zeta potential, drug aggregation state, and onset of by-products. Our analyses highlighted that the most diluted formulation, kept at room temperature, showed the greatest changes in the aggregation state of the drug and accordingly the highest cytotoxicity. These findings are clinically relevant since the lower dosages are addressed to the more vulnerable patients. Therefore, the centralization of the dilution of AmBisome® at the pharmacy is of fundamental importance for assuring patient safety, and at the same time for reducing medication waste, as we demonstrated using the cost-saving analysis of drug expense per therapy carried out at the G. Gaslini children hospital. [ABSTRACT FROM AUTHOR]

The recipe for making Turkish coffee in some parts of former Yugoslavia calls for the dilution of the turbid liquid with lukewarm water just before the boiling point is reached. The enigmatic gastronomic purpose of this step notwithstanding, here it is being used as an inspiration for deriving a simple stabilization step for protocols for the synthesis of fine particle colloids. The dilution step inspired by coffee-making was performed in a protocol for the synthesis of hydroxyapatite nanoparticles by their precipitation from supersaturated alkaline aqueous solutions. The implementation of this step in the post-precipitation stage, concurrently with boiling, evidently improved the stability of the nanoparticle colloids. The stabilization effect was limited to the suspensions where the parent solution was equilibrated with the fresh precipitate and was not reproduced in colloids comprising HAp nanoparticles redispersed in deionized water. The dilution step produced a mild and counterintuitive increase in crystallinity, suggesting complex recrystallization mechanisms driven by mutually antagonistic dissolution caused by the dilution and reprecipitation caused by the heating to be responsible for the observed increase in stability. Incongruent dissolution favoring a less entropic surface order and reduced charge screening entailing the expansion of the Debye lengths were suggested as complementary mechanisms explaining the improvements in stability caused by adding this simple and economical, yet very efficacious touch to the synthesis. It is concluded that unconventional protocols in spheres other than the scientific and heritages routinely discarded as disreputable could be sources of insight relevant to a plethora of distant domains and disciplines. [ABSTRACT FROM AUTHOR]

Herein, we describe the synthesis of pH-sensitive lipophilic colchicine prodrugs for liposomal bilayer inclusion, as well as preparation and characterization of presumably stealth PEGylated liposomes with above-mentioned prodrugs. These formulations liberate strongly cytotoxic colchicinoid derivatives selectively under slightly acidic tumor-associated conditions, ensuring tumor-targeted delivery of the compounds. The design of the prodrugs is addressed to pH-triggered release of active compounds in the slight acidic media, that corresponds to tumor microenvironment, while keeping sufficient stability of the whole formulation at physiological pH. Correlations between the structure of the conjugates, their hydrolytic stability, colloidal stability, ability of the prodrug retention in the lipid bilayer are described. Several formulations were found promising for further development and in vivo investigations. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Reversible addition‐fragmentation chain transfer (RAFT)‐mediated polymerization‐induced self‐assembly (PISA) of star block copolymer and linear block copolymer using a binary mixture of a star‐like macro‐RAFT agent and a linear macro‐RAFT agent is reported. With this formulation, star block copolymer and diblock copolymer were formed simultaneously to generate colloidally stable star/linear block copolymer assemblies. Size exclusion chromatography (SEC) analysis confirmed the presence of two types of polymers in the final samples. The molar ratio of the star‐like macro‐RAFT agent and the linear macro‐RAFT agent has a significant impact on the morphology of polymer assemblies. It was found that increasing the amount of star‐like macro‐RAFT agent facilitated the formation of higher‐order morphologies. Additionally, effects of other reaction parameters including the length/number of the arm of the star‐like macro‐RAFT agent, degree of polymer (DP), monomer concentration on the morphology of star/linear block copolymer assemblies were also investigated. We expect that this work will offer new possibilities for the scalable preparation of polymer assemblies with unique structures and functions. [ABSTRACT FROM AUTHOR]

Aptamers are widely used in biosensing due to their specific sensitivity toward many targets. Thus, gold nanoparticle (AuNP) aptasensors are subject to intense research due to the complementary properties of aptamers as sensing elements and AuNPs as transducers. We present herein a novel method for the functional coupling of thrombin‐specific aptamers to AuNPs via an anionic, redox‐active poly(ferrocenylsilane) (PFS) polyelectroyte. The polymer acts as a co‐reductant and stabilizer for the AuNPs, provides grafting sites for the aptamer, and can be used as a redox sensing element, making the aptamer‐PFS‐AuNP composite (aptamer‐AuNP) a promising model system for future multifunctional sensors. The aptamer‐AuNPs exhibit excellent colloidal stability in high ionic strength environments owing to the combined electrosteric stabilizing effects of the aptamer and the PFS. The synthesis of each assembly element is described, and the colloidal stability and redox responsiveness are studied. As an example to illustrate applications, we present results for thrombin sensitivity and specificity using the specific aptamer. [ABSTRACT FROM AUTHOR]

The size of acrylamide‐based microgels can be decreased by addition of ionic surfactants during the classical dispersion polymerization. Nevertheless, the mechanism of such syntheses is not well understood yet. Here, a "Limited Aggregation Model" is proposed by analogy with the limited coalescence mechanism occurring for Pickering emulsion stabilization. In such a model, nuclei aggregate until a constant, high enough surfactant surface coverage is reached, which ensures colloidal stability. Consequently, the total surface of the growing particles, linked to the inverse of their size, is linearly dependent on the surfactant concentration. This law is verified if the surfactant/polymer particle interaction is high enough to guarantee a "total adsorption" of the surfactants onto the particles. This simple model fits very well with all the data extracted from the literature, including very different synthesis conditions. Finally, it not only permits to predict the microgels size, but it is also an interesting tool to investigate the role of each synthesis parameter like initiator, solvent or polymer. For instance, it shows that the surfactant role is not linked to its charge, proving that a phenomenon complementary to the electrostatic repulsion, related to the surfactant tail, ensures the colloidal stability of the growing collapsed microgels. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid dielectric nanomaterials are vital for OTFT applications due to their unique combination of organic dielectric and inorganic properties. Despite the challenges in preparing stable titania (TiO2) nanoparticles, we successfully synthesized colloidally stable organic–inorganic (O-I) TiO2 hybrid nanoparticles using an amphiphilic polymer as a stabilizer through a low-temperature sol–gel process. The resulting O-I TiO2 hybrid sols exhibited long-term stability and formed a high-quality dielectric layer with a high dielectric constant (κ) and minimal leakage current density. We also addressed the effect of the ethylene oxide chain within the hydrophilic segment of the amphiphilic polymer on the dielectric properties of the coating film derived from O-I TiO2 hybrid sols. Using the O-I TiO2 hybrid dielectric layer with excellent insulating properties enhanced the electrical performance of the gate dielectrics, including superior field-effect mobility and stable operation in OTFT devices. We believe that this study provides a reliable method for the preparation of O-I hybrid TiO2 dielectric materials designed to enhance the operational stability and electrical performance of OTFTs. [ABSTRACT FROM AUTHOR]

The addition of salt has a pronounced impact on the stability of nanoparticles. By varying the salt types and concentrations, the structure of spray-dried supraparticles from binary SiO 2 nanoparticle dispersions can be tuned from core-shell to Janus-like and well-mixed. The surface roughness and porosity are modified accordingly. In summary, this study presents a feasible way to synthesize particles with different supraparticular structures by elucidating the role of ionic strength on different sizes of nanoparticles. [Display omitted] The structure and texture of supraparticles determine their properties and performance, thus playing a critical role in research studies as well as industrial applications. The addition of salts is a well-known strategy to manipulate the colloidal stability of nanoparticles. In this study, this approach is used to tune the structure of spray-dried supraparticles. Three different salts (NaCl, CaCl 2 , and AlCl 3) were added to binary silica (SiO 2) nanoparticle dispersions (of 40 and 400 nm in size) to change their colloidal stability by lowering the electrostatic repulsion or enhancing the cation bridging. Dependent on the cation valence of the added salt and the nanoparticle size, the critical salt concentration, which yields nanoparticle agglomeration, is reached at different salt amounts. This phenomenon is exploited to tune the final structure of supraparticles - obtained by spray-drying binary dispersions - from core-shell to Janus-like to well-mixed structures. This consequently also tunes textural properties, like surface roughness and the pore system of the obtained supraparticles. Our results provide insights for controlling the structure of spray-dried supraparticles by manipulating the stability of binary nanoparticle dispersions, and they establish a framework for composite particle design. [ABSTRACT FROM AUTHOR]

Zeta potential is an important colloid parameter that dictates many intriguing phenomena such as colloid stability/aggregation, electrophoretic deposition and particle separation technology. Zeta potential is commonly used to characterise colloid particles' electrostatic interactions coupled with other forces such as van der Waals attraction, hydration and steric forces. However, the measurement of zeta potential involves complicated sample preparation and instrument/theory selection, often resulting in inaccurate measurement. Here, we developed a simple method that combines Stern–Grahame and Gouy–Chapman theories, for estimating zeta potential using parameters such as acid site pKa, acid site density and particle size. The method is applied to a wide range of carboxylic acids' functionalised colloid particles with various pKa. Results show that the new method is capable of capturing zeta potential dependence on pKa and pH. The new method can be applied to particles with complicated or multiple acid/base sites. Without the need for sample preparation/instrument, this new method is believed to save efforts for estimating zeta potential with good accuracy. [ABSTRACT FROM AUTHOR]

Polyethylene glycol (PEG) exhibits poor residence on mucosal membranes in the presence of biological fluid, and the influence of PEG boronation on its properties has never been investigated. This project aimed to synthesise boronated 4‐arm PEG and evaluate their pH stability, thermal properties and mucoadhesiveness for potential transmucosal applications. Two types of boronated 4‐armed PEG (B4PEG1 & B4PEG2) and a boronated linear PEG (BLPEG) were synthesized. The degree of boronation, mucoadhesiveness, thermal and pH stability of the polymers were assessed using 1H NMR spectroscopy, viscometry, thermogravimetric analysis and UV–visible spectroscopy, respectively. Gel Permeation Chromatography was employed to confirm PEG boronation. The respective degrees of boronation for B4PEG1 and B4PEG2 were 32.8 % and 46.2 %. The molecular architecture and degree of PEG boronation had a remarkable influence on mucoadhesiveness, pH, and thermal stability. B4PEG2, with a branched architecture and the greatest degree of boronation, exhibited superior mucoadhesiveness and colloidal stability at pH 4 to 8, relative to B4PEG1 and BLPEG. Boronation improved the thermal stability of 4‐arm PEG. This study is the first to demonstrate that PEG boronation could enhance the pH‐sensitivity, thermal stability and mucoadhesiveness of 4‐arm PEG. Boronated 4‐arm PEGs could serve as mucoadhesive polymeric excipients for transmucosal drug delivery. [ABSTRACT FROM AUTHOR]

[Display omitted] Magneto-mechanical actuation (MMA) using the low-frequency alternating magnetic fields (AMFs) of magnetic nanoparticles internalized into cancer cells can be used to irreparably damage these cells. However, nanoparticles in cells usually agglomerate, thus greatly augmenting the delivered force compared to single nanoparticles. Here, we demonstrate that MMA also decreases the cell viability, with the MMA mediated by individual, non-interacting nanoparticles. The effect was demonstrated with ferrimagnetic (i.e., permanently magnetic) barium-hexaferrite nanoplatelets (NPLs, ∼50 nm wide and 3 nm thick) with a unique, perpendicular orientation of the magnetization. Two cancer-cell lines (MDA-MB-231 and HeLa) are exposed to the NPLs in-vitro under different cell-culture conditions and actuated with a uniaxial AMF. TEM analyses show that only a small number of NPLs internalize in the cells, always situated in membrane-enclosed compartments of the endosomal-lysosomal system. Most compartments contain 1–2 NPLs and only seldom are the NPLs found in small groups, but never in close contact or mutually oriented. Even at low concentrations, the single NPLs reduce the cell viability when actuated with AMFs, which is further increased when the cells are in starvation conditions. These results pave the way for more efficient in-vivo MMA at very low particle concentrations. [ABSTRACT FROM AUTHOR]

Liposomes are spherical lipidic nanocarriers composed of natural or synthetic phospholipids with a hydrophobic bilayer and aqueous core, which are arranged into a polar head and a long hydrophobic tail, forming an amphipathic nano/micro-particle. Despite numerous liposomal applications, their use encounters many challenges related to the physicochemical properties strongly affected by their constituents, colloidal stability, and interactions with the biological environment. This review aims to provide a perspective and a clear idea about the main factors that regulate the liposomes' colloidal and bilayer stability, emphasising the roles of cholesterol and its possible alternatives. Moreover, this review will analyse strategies that offer possible approaches to provide more stable in vitro and in vivo liposomes with enhanced drug release and encapsulation efficiencies. [ABSTRACT FROM AUTHOR]

This study aimed to design and develop novel surface-engineered Depofoam formulations to extend the drug delivery to the prescribed time. The objectives are to prevent the formulation from burst release, rapid clearance by tissue macrophages, and instability and to analyze the impact of process and material variables in the characteristics of formulations. This work employed a quality-by-design coupled failure modes and effects analysis (FMEA)-risk assessment strategy. The factors for the experimental designs were chosen based on the FMEA results. The formulations were prepared by the double emulsification method followed by surface modification and characterized in terms of critical quality attributes (CQAs). The experimental data for all these CQAs were validated and optimized using the Box–Behnken design. A comparative drug release experiment was studied by the modified dissolution method. Furthermore, the stability of the formulation was also assessed. In addition, the impact of critical material attributes and critical process parameters on CQAs was evaluated using FMEA risk assessment. The optimized formulation method yielded high encapsulation efficiency (86.24 ± 0.69%) and loading capacity (24.13 ± 0.54%) with an excellent zeta potential value (-35.6 ± 4.55mV). The comparative in vitro drug release studies showed that more than 90% of the drug's release time from the surface-engineered Depofoam was sustained for up to 168 h without burst release and ensured colloidal stability. These research findings revealed that Depofoam prepared with optimized formulation and operating conditions yielded stable formulation, protected the drug from burst release, provided a prolonged release, and sufficiently controlled the drug release rate. [ABSTRACT FROM AUTHOR]

The commercially available magnetic nanoparticles (MNPs) in the solid powder form are typically colloidally unstable under the aqueous environment and can easily settle out without modification. Thus, surface functionalization with polyelectrolyte is required to improve the colloidal stability of MNP systems prior to their applications. In this study, the effect of various factors during the functionalization process, including type of polyelectrolyte, solution pH, ionic strength and particle-to-polyelectrolyte ratio, on the colloidal stability of the functionalized MNPs was evaluated experimentally and theoretically. It was revealed that PSS-70 k and PDDA(M) imparted better colloidal stability toward the functionalized MNPs as compared to PEG, PSS-1000 k and PDDA(L). The optimal pH to produce PSS-70 k- and PDDA(M)-functionalized MNPs is found to be pH 3 and 11, respectively. In addition, the optimum MNP/polyelectrolyte mass ratio was revealed to be 1:5 and 1:0.5 for the synthesis of PSS-70 k- and PDDA(M)-functionalized MNP systems, respectively. The colloidal stability of both PSS-70 k- and PDDA(M)-functionalized MNPs was severely impeded by the presence of free ionic species in the solution during the functionalization process. Lastly, the mathematical analysis based on DLVO theory was consistent and well aligned with the experimental findings. [ABSTRACT FROM AUTHOR]

Dispersibility and stability of nanoparticles (NPs) in the biological medium are playing a major role on their size, fate, transport, delivered dose to cells, and consequently to their toxicological response in vitro. However, these parameters are frequently confused and therefore very poorly characterized. Here, we critically discuss the definition and characterization of dispersibility and stability of NPs for in vitro studies. We provide a methodology based on static multiple light scattering (SMLS), dynamic light scattering (DLS), and scanning electron microscopy (SEM) measurements to characterize the NP dispersibility and stability in complex biological media. This methodology was applied to one pristine and two food-grade TiO2 NPs dispersed in commonly used cell culture media supplemented with various BSA concentrations. Dispersibility was characterized by measuring the NP size and homogeneity after applying an optimized dispersion protocol. Colloidal, gravitational, and macroscopic stabilities were distinguished by measuring the NP zeta potential, settling velocity, and Turbiscan stability index (TSI), respectively. This approach allowed to monitor in real time the NP stability instead of predictions based on initial assays such as size and zeta potential. The results also proved that (i) best NP dispersibility does not ensure the best stability, (ii) NP colloidally stable does not imply their gravitational stability in the biological medium, and (iii) TSI is a more reliable measurand of colloidal stability compared to zeta potential. [ABSTRACT FROM AUTHOR]

Serum albumin is a popular macromolecule for studying the effect of proteins on the colloidal stability of nanoparticle (NP) dispersions, as well as the protein–nanoparticle interaction and protein corona formation. In this work, we analyze the specific conformation-dependent phase, redox, and fatty acid delivery properties of bovine albumin in the presence of shungite carbon (ShC) molecular graphenes stabilized in aqueous dispersions in the form of NPs in order to reveal the features of NP bioactivity. The formation of NP complexes with proteins (protein corona around NP) affects the transport properties of albumin for the delivery of fatty acids. Being acceptors of electrons and ligands, ShC NPs are capable of exhibiting both their own biological activity and significantly affecting conformational and phase transformations in protein systems. [ABSTRACT FROM AUTHOR]

Poly(tertiary amine‐oxide)‐based polymeric nanocarriers have showed more functionalities than stealthy PEG‐based analogs due to the structure of phospholipid affinitive N‐oxides groups, which has attracted considerable attention to the synthesis of various zwitterionic copolymers with tertiary amine‐oxide grafts for enhanced anticancer drug delivery. However, poly(tertiary amine‐oxide)‐based amphiphilic copolymers with tumor intracellular microenvironment sensitivities, to the knowledge, have been rarely reported likely due to the lack of a controlled synthetic strategy. Herein, a reducible zwitterionic copolymer, poly(ε‐caprolactone)25‐SS‐poly(2‐(N‐oxide‐N,N‐diethylamino)ethyl methacrylate)30 (PCL25‐SS‐OPDEA30) is designed and synthesized successfully via combination of controlled polymerization techniques and post polymerization modification. Specifically, postoxidation of poly(tertiary amine) is confirmed to be a better synthetic strategy toward a well‐defined polymer structure relative to direct polymerization of N,N‐diethylaminoethyl methacrylate (ODEA). The effect of disulfide bridges on the self‐assembly behaviors, in vitro drug loading and drug release properties is investigated in detail. Notablely, the resulting micelles self‐assembled from PCL25‐SS‐OPDEA30 show much greater colloidal stability, higher drug loading content (DLC), and better in vitro tumor cell inhibition than the reduction‐insensitive counterparts. Overall, this study reports a robust strategy toward zwitterionic nanomedicines for on‐demand anticancer drug delivery. [ABSTRACT FROM AUTHOR]

[Display omitted] Ion specific effects on the charging and aggregation features of zein nanoparticles (ZNP) were studied in aqueous suspensions by electrophoretic and time-resolved dynamic light scattering techniques. The influence of mono- and multivalent counterions on the colloidal stability was investigated for positively and negatively charged particles at pH values below and above the isoelectric point, respectively. The sequence of the destabilization power of monovalent salts followed the prediction of the indirect Hofmeister series for positively charged particles, while the direct Hofmeister series for negatively charged ones assumed a hydrophobic character for their surface. The multivalent ions destabilized the oppositely charged ZNPs more effectively and the aggregation process followed the Schulze-Hardy rule. For some multivalent ions, strong adsorption led to charge reversal resulting in restabilization of the suspensions. The experimental critical coagulation concentrations (CCCs) could be well-predicted with the theory developed by Derjaguin, Landau, Verwey and Overbeek indicating that the aggregation processes were mainly driven by electrical double layer repulsion and van der Waals attraction. The ion specific dependence of the CCCs is owing to the modification of the surface charge through ion adsorption at different extents. These results are crucial for drug delivery applications, where inorganic electrolytes are present in ZNP samples. [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles (ZnO NPs) have a wide range of applications, and their properties can be significantly affected by gamma (γ) radiation, particularly in metal oxide semiconductor-based devices. This study investigates the impact of γ-irradiation on the physicochemical properties of ZnO NPs. The ZnO NPs were synthesized using a microwave method with zinc nitrate hexahydrate as a precursor and urea as a fuel. These synthesized ZnO NPs were exposed with γ rays emitted from 60Co radioactive source at different doses (0, 25, 50, and 75 kGy). We systematically examined the effects of γ irradiation on the structure, optical properties, and colloidal stability of the ZnO NPs using various techniques, including XRD, Raman spectroscopy, FTIR, SEM, UV–visible absorption, and zeta potential/particle size analysis (ZP/PSA). The characterization results revealed that γ irradiation caused significant alterations in the microstructure of ZnO NPs, resulting in reduced crystallite and grain sizes. Additionally, the optical properties and colloidal stability were found to be dose-dependent, with absorption spectra shifting towards the blue region, an increase in optical bandgap, and a decrease in zeta potential values as the dose rate of γ radiation increased. [ABSTRACT FROM AUTHOR]

The preservative of natural rubber latex (NRL) is essentially a kind of bactericide or bacteriostat, mainly used for sterilisation or inhibit bacterial breeding, which will improve the pH of latex. To maintain the colloidal stability and consider the needs of reality manufacture, the NRL preservative also needs to have the advantages in terms of low price, ease to obtain and use, low toxicity, etc. In this study, a derivative of s-triazine (HT), a derivative of 2-methyl-4-isothiazolin-3-one (MI) and 2-methyl-5-chloro-4-isothiazolin-3-one (CMI) mixture (KS) are chosen as a non-ammonia preservative for NRL, which their effect on the structure and properties of NRL was investigated. The results of vulcanisation characteristics showed that the temperature dependence of the samples preserved by preservative HT was lower than that of ammonia and KS during the induction period (t10). The test results of molecular weight and cross-linking density showed that the addition of preservative HT could protect the molecular chain structure of NR. In terms of physical and mechanical properties, the performance of sample HT is similar to that of sample ammonia, but after thermo-oxidative ageing at 100 °C for 24 h, the tensile strength retention rate of the sample preserved by the preservative HT can still reach 78%, which is higher than that of the ammonia preserved sample. Therefore, Preservative HT is a relatively better preservative. Its addition will not affect the structure of NRL and the prepared NR has good physical and mechanical properties as well as thermo-oxidative resistance. It can be considered to replace ammonia as the NRL preservative. [ABSTRACT FROM AUTHOR]

Oral cancer is a disease with high morbidity and mortality worldwide and greatly impacts the quality of life, especially in patients with advanced stages. Photodynamic therapy (PDT) is one of the most effective clinical treatments for oral cancers. However, most clinically applied photosensitizers have several deficiencies, including oxygen dependence, poor aqueous solubility, and a lack of tumor-targeting ability. Herein, the carrier-free multifunctional Sorafenib (Sor), chlorin e6 (Ce6), and Fe3+ self-assembly co-delivery nanoparticles (Sor-Ce6 NPs) were constructed via combining a ferroptosis inducer Sor and a photosensitizer Ce6 for synergetic therapy. The as-synthesized Sor-Ce6 NPs presented excellent colloidal stability and water dispersity with good in vivo tumor-targeting ability. More significantly, the low dose of Sor-Ce6 NPs had little dark toxicity but produced significantly enhanced ROS and supplied O 2 sustainably to increase phototoxicity through ferroptosis pathway. Notably, the Sor-Ce6 NPs showed significantly higher in vitro and in vivo anti-tumor efficacy than the Sor/Ce6 mixture due to the improvement of cellular uptake and the incorporation of foreign Fe ions in the system, which also confer the T 1 magnetic resonance-guided imaging ability to the formed Sor-Ce6 NPs. Our study demonstrates a promising self-assembled strategy for overcoming hypoxia-related PDT resistance for oral cancer treatment. • Carrier-free Sorafenib-Ce6 self-assemblies are designed by molecular simulation • The effect of oxygen-dependent PDT is boosted by inducing ferroptosis in oral cancer • Exogenous Fe3+ enhanced Sorafenib's ferroptosis inducing effect in oral cancer • Sor-Ce6 NPs is suitable for fluorescence and T 1 MR dual-modal imaging-guided PDT [Display omitted] [ABSTRACT FROM AUTHOR]

Zinc oxide nanoparticles (ZnO NPs) have a wide range of applications, and their properties can be significantly affected by gamma (γ) radiation, particularly in metal oxide semiconductor-based devices. This study investigates the impact of γ-irradiation on the physicochemical properties of ZnO NPs. The ZnO NPs were synthesized using a microwave method with zinc nitrate hexahydrate as a precursor and urea as a fuel. These synthesized ZnO NPs were exposed with γ rays emitted from 60Co radioactive source at different doses (0, 25, 50, and 75 kGy). We systematically examined the effects of γ irradiation on the structure, optical properties, and colloidal stability of the ZnO NPs using various techniques, including XRD, Raman spectroscopy, FTIR, SEM, UV–visible absorption, and zeta potential/particle size analysis (ZP/PSA). The characterization results revealed that γ irradiation caused significant alterations in the microstructure of ZnO NPs, resulting in reduced crystallite and grain sizes. Additionally, the optical properties and colloidal stability were found to be dose-dependent, with absorption spectra shifting towards the blue region, an increase in optical bandgap, and a decrease in zeta potential values as the dose rate of γ radiation increased. [ABSTRACT FROM AUTHOR]

Demetallization pretreatment is of great significance for the re-refining of used lubricating oil (ULO) by catalytic hydrogenation. Calcium-containing detergents colloidal stability, pyrolysis properties and kinetics studies have great significance for the demetallization pretreatment, re-refining, and resource utilization of ULO. The present study is focused on the pyrolysis mechanism and determining an accurate pyrolysis kinetic model for the removal of calcium from ULO using vulcanized calcium alkylphenolate (T-115B) colloidal as a model compound. Colloidal stability, pyrolysis process and thermal decomposition products have been studied by DLS, TEM, FTIR spectroscopy and XPS. The reaction energy for primary and secondary dissociation is calculated using the B3LYP-D3(BJ)/6-31g* method. The pyrolysis characteristics at different heating rates have been investigated by TG/DTA, and based on iso-conversional and master plot methods, E and kinetic equation have been determined, which revealed that the process can be divided into two distinct phases and the pyrolysis mechanism and function are necessarily described by a two-step model. The colloid was relatively stable when the temperature is lower than 395 K. When the temperature rises, compounds occur thermal decomposition, alkyl-CH2–S bond may be the trigger bond in the initiation process, and CaCO3 is the main degradation product. Based on iso-conversional methods (KAS and FWO) and master plot methods, values of E are determined as 96.67 and 100.78 kJ mol−1, respectively. And the pyrolysis reaction in stage 1 indicated that the most probable kinetic model followed an Fn mechanism with n = 1.39, and the second stage was also controlled by an Fn mechanism, but with n = 0.86. [ABSTRACT FROM AUTHOR]

A stable suspension of nanoparticles is generally achieved by modifying the surface properties of the nanoparticles using a surfactant. This is to create a surface charge on the nanoparticles which prevents them from forming aggregates. This phenomenon is very sensitive to changes in the local environment. Conventional optical tweezers though capable of trapping sub‐micrometer particles are not known to trap single nanoparticles. However, the stability and dynamics of a suspension of nanoparticles can be probed through the changes in the fluctuations of an optically trapped microsphere that has been added to the suspension. Adding microspheres to the nanoparticle suspension can affect the stability depending on the surface charges the microparticles themselves have. The study reports here on the variation of the dynamics of suspended nanoparticles, which have a positive surface charge, when silica microspheres, which are negatively surface charged, are added to the suspension. With the addition of silica beads, there is agglomeration of the nanoparticles. The dynamics of these agglomerated structures are then probed by measuring the Brownian fluctuations of an optically trapped silica bead. These results are in sharp contrast to those of earlier studies carried out with suspensions of identical nanoparticles but with negative surface charge. [ABSTRACT FROM AUTHOR]

This study centers on the environmentally benign synthesis of zinc oxide nanoparticles (ZnO NPs) derived from Zn (CH3COO)2·2H2O and Moringa seeds. The synthesized nanostructures underwent comprehensive characterization utilizing diverse analytical techniques, encompassing X-ray diffraction (XRD), UV–VIS spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. XRD measurements coupled with W–H plot transformation unequivocally confirmed the formation of ZnO nanostructures, characterized by an average size of 24.9 nm. UV–VIS spectroscopy, complemented by Kubelka Munk curve analysis, elucidated the direct conduction and determined a bandgap of 3.265 eV. FESEM analysis revealed minimal particle aggregation, showcasing well-defined grain boundaries spanning sizes from 20.4 to 87.7 nm. XPS analysis substantiated the presence of Zn (2p), Zn (3p), Zn (3d), and O (1s). Raman spectroscopy identified E2H as the predominant mode, followed by E1(TO) and (E2H-E2L). ZnO thin films, fabricated via pulsed laser deposition (PLD) and deposited onto silicon (100) substrates, exhibited exemplary morphology and discernible topography, characterized by a normal grain size distribution. Zeta potential tests yielded a value of approximately (z ~ − 43.8 mV), indicative of the commendable stability of the colloidal suspension, likely attributable to low particle aggregation. Dielectric measurements conducted on sintered pellets at 900 °C unveiled elevated capacitance and dielectric constant at low frequencies across the temperature range of 289.935–310 K. These findings affirm the potential utility of environmentally synthesized ZnO for a spectrum of applications, including energy devices and nanofluids. [ABSTRACT FROM AUTHOR]

The paper presents the colloidal and thermal stability of the three‐component hybrid materials containing halloysite, polysaccharides (alginic acid, cationic cellulose and hydroxyethyl cellulose) and Tritons. TX‐100, TX‐165 and TX‐405 were used as non‐ionic surfactants. Stability and other properties of the hybrid materials were tested by the following methods: UV–Vis, TGA (thermogravimetric analysis) and DSC (differential scanning calorimetry), CHN (elemental analysis), SEM‐EDX (scanning electron microscopy with energy dispersive X‐ray spectroscopy) and tensiometry. According to the results with the increasing polymer concentration the colloidal stability of the tested systems also increases. Moreover, the addition of the surfactants causes the increase of polysaccharide adsorption but the colloidal stability of the tested systems decreases due to large weights of formed aggregates. As follows from the thermal analysis, the comparison of the TG/DTG‐DSC curves obtained for the investigated polymers confirms that their thermal decomposition courses have some common features. The obtained results have the application potential in the formation of the materials for the pollutants removal from water and sewages. [ABSTRACT FROM AUTHOR]

The evolution and rapid spread of multidrug-resistant (MDR) bacterial pathogens have become a major concern for human health and demand the development of alternative antimicrobial agents to combat this emergent threat. Conventional intracellular methods for producing metal nanoparticles (NPs) using whole-cell microorganisms have limitations, including binding of NPs to cellular components, potential product loss, and environmental contamination. In contrast, this study introduces a green, extracellular, and sustainable methodology for the bio-materialization of silver NPs (AgNPs) using renewable resource cell-free yeast extract. These extracts serve as a sustainable, biogenic route for both reducing the metal precursor and stabilizing the surface of AgNPs. This method offers several advantages such as cost-effectiveness, environment-friendliness, ease of synthesis, and scalability. HR-TEM imaging of the biosynthesized AgNPs revealed an isotropic growth route, resulting in an average size of about ~ 18 nm and shapes ranging from spherical to oval. Further characterization by FTIR and XPS results revealed various functional groups, including carboxyl, hydroxyl, and amide contribute to enhanced colloidal stability. AgNPs exhibited potent antibacterial activity against tested MDR strains, showing particularly high efficacy against Gram-negative bacteria. These findings suggest their potential role in developing alternative treatments to address the growing threat of antimicrobial resistance. Additionally, seed priming experiments demonstrated that pre-sowing treatment with AgNPs improves both the germination rate and survival of Sorghum jowar and Zea mays seedlings. Key points: •Yeast extract enables efficient, cost-effective, and eco-friendly AgNP synthesis. •Biosynthesized AgNPs showed strong antibacterial activity against MDR bacteria. •AgNPs boost seed germination and protect against seed-borne diseases. [ABSTRACT FROM AUTHOR]

Recently, suitably sized polymer-based nanogels containing functional groups for the binding of biologically active substances and ultimately degradable to products that can be removed by glomerular filtration have become extensively studied systems in the field of drug delivery. Herein, we designed and tailored the synthesis of hydrophilic and biodegradable poly[N-(2-hydroxypropyl) methacrylamide-co-N,N′-bis(acryloyl) cystamine-co-6-methacrylamidohexanoyl hydrazine] (PHPMA-BAC-BMH) nanogels. The facile and versatile dispersion polymerization enabled the preparation of nanogels with a diameter below 50 nm, which is the key parameter for efficient and selective passive tumor targeting. The effects of the N,N′-bis(acryloyl) cystamine crosslinker, polymerization composition, and medium including H2O/MetCel and H2O/EtCel on the particle size, particle size distribution, morphology, and polymerization kinetics and copolymer composition were investigated in detail. We demonstrated the formation of a 38 nm colloidally stable PHPMA-BAC-BMH nanogel with a core–shell structure that can be rapidly degraded in the presence of 10 mM glutathione solution under physiologic conditions. The nanogels were stable in an aqueous solution modeling the bloodstream; thus, these nanogels have the potential to become highly important carriers in the drug delivery of various molecules. [ABSTRACT FROM AUTHOR]

In the present work, we demonstrate studies involving the influence of the formulation composition on the physicochemical properties of nanocarriers: solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs). Novel lipid-origin platforms were prepared using two "green" betaine-based surfactants, cocamidopropyl betaine (ROKAmina K30) and coco betaine (ROKAmina K30B), in combination with three different solid lipids, cetyl palmitate (CRODAMOL CP), trimyristin (Dynasan 114), and tristearin (Dynasan 118). Extensive optimization studies included the selection of the most appropriate lipid and surfactant concentration for effective SLN and NLC stabilization. The control parameters involving the hydrodynamic diameters of the obtained nanocarriers along with the size distribution (polydispersity index) were determined by dynamic light scattering (DLS), while shape and morphology were evaluated by atomic force microscopy (AFM) and transmission electron microscopy (TEM). Electrophoretic light scattering (ELS) and turbidimetric method (backscattering profiles) were used to assess colloidal stability. The studied results revealed that both betaine-stabilized SLN and NLC formulations containing CRODAMOL CP as lipid matrix are the most monodisperse and colloidally stable regardless of the other components and their concentrations used, indicating them as the most promising candidates for drug delivery nanosystems with a diverse range of potential uses. [ABSTRACT FROM AUTHOR]

In this work, Lavandula x intermedia essential oil (LEO) was encapsulated in lipid-based nanoemulsions (NanoLEO) using the solvent-displacement technique. In order to preserve the colloidal stability of the formulation, LEO was appropriately doped with the incorporation of different levels of a water-insoluble oil used as a ripening inhibitor. All the nanoemulsion samples were evaluated in terms of the impact of the water-insoluble oil on the nanoemulsion formation, physical–chemical properties, and antibacterial effectiveness against E. coli (Gram-negative) and B. cereus (Gram-positive). The presence of the inert oil added benefits to the formulations in terms of appearance, colloidal stability, and loss of volatile components. However, the antimicrobial activity of the nanoemulsions dramatically decreased with the ripening inhibitor addition, probably because it hampered the internalization of the antimicrobial components of LEO within the bacterial cell membranes, thus nullifying the delivery ability of the nanoemulsion formulation. On the contrary, the undoped NanoLEO formulation showed unaltered antibacterial activity in both E. coli and B. cereus up to 40 weeks from the preparation. [ABSTRACT FROM AUTHOR]

Terpenoids play a major role in agriculture, given their fungicidal and herbicidal actions, as well as their favorable toxicological, ecotoxicological, and environmental profiles. Despite all these advantages, terpenoids are reported to be unstable in direct sunlight and atmospheric conditions, so both commercial suppliers and scientific literature foresee their protection by encapsulation. The so‐called microcapsules (μCaps) are therefore of high relevance as drug‐delivery vectors, but very few techniques focus on their surface as well as on their morphological characterization. Indeed, these aspects are of great importance, given that their surface chemistry governs both their colloidal stability and mechanism of action. Common analysis techniques, such as chromatographic and mass‐spectrometric ones, are destructive, require sample preparation, and do not result in the complete morphological characterization of the microcapsules. Micro‐Raman spectroscopy, in conjunction with the surface‐enhanced Raman spectroscopy (SERS) effect, offers a valuable alternative method of investigation capable of achieving a complete and non‐destructive morphological characterization of the terpenoid‐encapsulating systems, the dimensions of which fall within the micrometric range. In addition, the SERS effect can be exploited by fabricating the microcapsules with gold nanostars (AuNSs) modified with chitosan and a SERS reporter (Nile Blue A). Thanks to the high contrast provided by the SERS signals of this tag, it was possible to localize and confirm the chitosan in the morphology of the microcapsules. The results of this study shed new light on the possibility of analyzing terpenoid‐encapsulating microcapsules and possibly other kinds of encapsulates brought by using Raman spectroscopy and by exploiting the SERS effect. [ABSTRACT FROM AUTHOR]