Colloidal Stability Research Articles

Formulation and evaluation of pazopanib-loaded PLGA nanoparticles for enhanced bioavailability and sustained release in cancer chemotherapy

The objective of this study was to develop and characterize a Nano formulation of Pazopanib using poly(DL-lactide-co-glycolide) (PLGA) for improved bioavailability and reduced systemic toxicity. Pazopanib, a tyrosine kinase inhibitor used in the treatment of renal cell carcinoma and soft tissue sarcoma, exhibits limited solubility and bioavailability, restricting its clinical efficacy. We employed an oil-in-water (o/w) emulsion solvent evaporation technique to prepare Pazopanib-loaded PLGA nanoparticles. Various formulations were optimized by adjusting the drug-to-polymer ratio, yielding spherical nanoparticles with an average size of 135 nm and a low polydispersity index, as confirmed by dynamic light scattering and transmission electron microscopy. The nanoparticles demonstrated a high entrapment efficiency of 33.9 ± 2.5% and a zeta potential of -20.12 mV, indicating good colloidal stability. Fourier transform infrared spectroscopy confirmed the compatibility of Pazopanib with PLGA and other excipients. The in vitro drug release studies revealed a sustained release profile over 7 days, contrasting with the rapid release from the free drug solution. These findings suggest that the developed PLGA-based nanoparticulate system could potentially enhance the therapeutic efficacy of Pazopanib by increasing its bioavailability and ensuring controlled release, thus offering a promising approach for cancer chemotherapy.

Poly Lactic Co-glycolic Acid d-α-tocopheryl Polyethylene Glycol 1000 Succinate Fabricated Polyethylene Glycol Hybrid Nanoparticles of Imatinib Mesylate for the Treatment of Glioblastoma Multiforme

Aims: This study aimed to develop Imatinib Mesylate (IMT)-loaded Poly Lactic-co-Glycolic Acid (PLGA)-D-α-tocopheryl polyethylene glycol succinate (TPGS)- Polyethylene glycol (PEG) hybrid nanoparticles (CSLHNPs) with optimized physicochemical properties for targeted delivery to glioblastoma multiforme. Background: Glioblastoma multiforme (GBM) is the most destructive type of brain tumor with several complications. Currently, most treatments for drug delivery for this disease face challenges due to the poor blood-brain barrier (BBB) and lack of site-specific delivery. Imatinib Mesylate (IMT) is one of the most effective drugs for GBM, but its primary issue is low bioavailability. Therefore, nanotechnology presents a promising solution for targeted IMT delivery to GBM. This article primarily explores the fabrication of IMT-loaded core-shell lipid-polymer hybrid nanoparticles (CSLHNPs) to achieve enhanced brain delivery with therapeutic efficacy. Objective: The primary objective of this study is to develop optimized, stable IMT-loaded hybrid nanoparticles with an encapsulated polymer matrix and to evaluate these nanoparticles using sophisticated instruments such as SEM and TEM to achieve smooth, spherical nanoparticles in a monodispersed phase. Method: The enhanced stable formulation yielded a notable increase in entrapment efficiency, reaching 58.89 ± 0.5%. The physical stability analysis of nanoparticles was assessed over 30 days under conditions of 25 ± 2°C and 60 ± 5% relative humidity. Hemolytic assays affirmed the biocompatibility and safety profile of the nanoparticles. in vitro drug release kinetics revealed a sustained IMT release over 48 hours. Results: The formulated CSLHNPs achieved a narrow size distribution with a mean vesicle diameter of 155.03 ± 2.41 nm and a low polydispersity index (PDI) of 0.23 ± 0.4, indicating monodispersity. A high negative zeta potential of -23.89 ± 3.47 mV ensured excellent colloidal stability in physiological conditions. XRD analysis confirmed the successful encapsulation of IMT within the nanoparticle matrix, with the drug transitioning to an amorphous state for enhanced dissolution. During Cell-Cell viability assays on LN229, glioblastoma cells were treated with IMT-loaded nanoparticles and showed a significantly enhanced inhibitory effect compared to free IMT. These hybrid nanoparticles demonstrated potential in reducing oxidative stress-induced cellular damage by mitigating reactive oxygen species (ROS). Thus, the prepared IMT hybrid nanoparticles showed higher cellular uptake and superior cytotoxicity compared to the plain drug. Conclusion: This study posits the IMT-PLGA-TPGS-DSPE PEG 2000-CSPLHNPs as a formidable and innovative drug delivery system for Glioblastoma Multiforme (GBM) treatment, warranting further exploration into their clinical application potential. Future work could involve conducting in vivo studies to evaluate the pharmacokinetics, biodistribution, and therapeutic efficacy of the IMT-PLGA-TPGS-DSPE PEG 2000-CSPLHNPs in animal models of Glioblastoma Multiforme (GBM). Additionally, further research may focus on optimizing the nanoparticle formulation for enhanced targeting capabilities, investigating long-term stability under varied storage conditions, exploring potential combination therapies to synergize with the nanoparticles, and assessing the scalability and manufacturability of the developed drug delivery system for potential clinical translation. Integration of advanced imaging techniques for real- time tracking and visualization of nanoparticle distribution within tumours could also be a promising direction for future investigations.

Rapid Room Temperature Entropy‐Stabilized Synthesis Enabling Super‐Stable Metal Halide Perovskite Semiconductor Colloidal Nanocrystals

AbstractAlthough high‐entropy materials have garnered extensive attention due to their substantially enhanced performance, their formation generally demands prolonged high‐temperature synthetic processes. Moreover, research on entropy‐stabilized halide perovskite (ESHP) semiconductor colloidal nanocrystals (NCs) is scarce. Herein, a highly efficient and rapid room temperature (RT) entropy‐stabilized approach in air is proposed, involving the concurrent incorporation of multi‐metal cations for the synthesis of high‐quality all‐inorganic ESHP NCs with near‐unity quantum yield and excellent colloidal stability. Remarkably, even after 8 months of aging in air, the ESHP NCs exhibited superior emission characteristics with a single‐exponential decay and maintained the initial NC monodispersity. Density functional theory calculations further demonstrated that the outstanding performance of ESHP NCs originated from the diminished crystal defects and a more robust octahedral structure. Significantly, this RT entropy‐driven synthesis can be extended to metal halide semiconductor NCs with diverse composition systems. The findings inspire new perspectives for entropy‐stabilized, high‐performance metal halide perovskite NCs toward versatile applications.

Effect of Polymer Network Architecture on Adsorption Kinetics at Liquid–Liquid Interfaces: A Comparison Between Poly(NIPAM-co-AA) Copolymer Microgels and Interpenetrating Network Microgels

Understanding the adsorption features of polymer microgels with different chemical compositions and structures is crucial in studying the mechanisms of respective emulsion stabilization. Specifically, the use of stimuli-responsive particles can introduce new properties and broaden the application range of such complex systems. Recently, we demonstrated that emulsions stabilized by microgels composed of interpenetrating networks (IPNs) of poly-N-isopropylacrylamide (PNIPAM) and polyacrylic acid (PAA) exhibit higher colloidal stability upon heating compared to PNIPAM homopolymer and other relevant PNIPAM-based copolymer counterparts. In the present work, using pendant drop tensiometry, we studied the evolution of water–tetradecane interfacial tension during the adsorption of PNIPAM-PAA IPN particles, comparing them with single-network P-(NIPAM-co-AA) and PNIPAM microgels. The results showed that, despite having the same chemical composition, copolymer particles exhibit completely different adsorption behavior in comparison to other microgel architectures. The observed disparity can be attributed to the nonuniform distribution of charged acrylic acid groups within the P-(NIPAM-co-AA) network obtained through precipitation polymerization. Oppositely, the presence of IPN architecture provides a uniform distribution of different monomers inside respective microgels. Additionally, hydrogen bonding between PNIPAM and PAA subchains appears to reduce the electrostatic energy barrier, enhancing the ability of IPN particles to successfully cover the liquid interface. Overall, our findings confirm the efficiency of using PNIPAM-PAA IPN microgels for the preparation of oil-in-water emulsions and their stability, even when the temperature rises above the lower critical solution temperature of PNIPAM.

O-substituted Tertiary Amine-chitosans as Promising Nanocarriers for siRNA Delivery.

The clinical translation of chitosan-based formulations for siRNA delivery has been partially limited by their poor stability/solubility at physiological conditions, although they have good biocompatibility and cost-effectiveness. In this study, the chitosan was O-substituted with diisopropylethylamine (DIPEA) groups, which improved its solubility at pH 7.4 by increasing the degree of ionization and enhanced the ability of chitosan to load siRNA at very low amine/phosphate (N/P) ratios. The O-DIPEAchitosan/ siRNA nanopolyplexes were self-assembled by complexation and presented positive Zeta potentials (ζ = +8 to +10 mV), spherical-like morphology, 200-300 nm size, low polydispersity index (PDI < 0.2), and were able to protect the siRNA from degradation by RNAse. Also, the resistance to albumin-induced disassembly and aggregation revealed both good structural and colloidal stabilities of the siRNA nanopolyplexes. The nanopolyplexes displayed low cytotoxicities in RAW 264.7 macrophages and were successfully uptaken by both macrophages and HeLa cells achieving internalization efficiency similar to Lipofectamine. A positive correlation was observed between the physicochemical properties of the siRNA nanocarrier and its transfection efficiency. A knockdown of about 60-70% of tumor necrosis factor alpha (TNFα) was reached in lipopolysaccharide-stimulated macrophages treated with O-DIPEA-chitosan/siTNFα nanopolyplexes. Overall, the results confirmed that O-DIPEA chitosans are promising carriers for siRNA delivery.

Polymer-Grafted Gold Colloids and Supracolloids: From Mechanisms of Formation to Dynamic Soft Matter.

Gold nanoparticles represent nanosized colloidal entities with high relevance for both basic and applied research. When gold nanoparticles are functionalized with polymer-molecule ligands, hybrid nanoparticles emerge whose interactions with the environment are controlled by the polymer coating layer: Colloidal stability and structure formation on the single particle level as well as at the supracolloidal scale can be enabled and engineered by tailoring the composition and architecture of this polymer coating. These possibilities in controlling structure formation may lead to synergistic and/or emergent functional properties of such hybrid colloidal systems. Eventually, the responsivity of the polymer coating to external triggers also enables the formation of hybrid supracolloidal systems with specific dynamic properties. This review provides an overview of fundamentals and recent developments in this vibrant domain of materials science.

Critical assessment of purification processes for the robust production of polymeric nanomedicine.

Polymeric nanoparticles are among the most widely used nanocarriers for delivering therapeutic molecules. However, their synthesis processes often generate undesirable impurities that could be toxic and challenging to eliminate. In this study, we compared three purification techniques - centrifugation, dialysis, and tangential flow filtration (TFF) - to evaluate their efficacy in removing residual drug, surfactant, and solvent while preserving the nanoparticles' physicochemical features (hydrodynamic size, zeta potential, polydispersity index). Centrifugation excels in eliminating unencapsulated drug and residual surfactant but significantly affects the nanoparticles' physicochemical properties, such as colloidal stability and size homogeneity. On the other hand, dialysis is a gentler technique effective in removing residual solvent but less so for residual surfactant and unencapsulated drug. TFF emerges as a balanced approach, offering a compromise between the two but none of these techniques achieves satisfactory purification at lab-scale alone. While each technique has its merits, none can meet all requirements independently. The optimal purification strategy often involves a combination of techniques, determined on a case-by-case basis considering factors like purity levels, time, costs, and the preservation of critical properties such as drug loading and colloidal stability. This study underscores the need for a nuanced approach in selecting purification strategies for polymeric nanoparticles in drug delivery applications.

Nano-bio interactions of Gum Arabic-stabilized lanthanide-based upconverting nanoparticles: in vitro and in vivo study.

Lanthanide-based nanoparticles (Ln-NPs) are highly valued for their unique optical and magnetic properties, making them useful in various scientific fields, including materials science and biomedicine. This study investigated the use of Gum Arabic (GA), a natural, non-toxic biopolymer, as capping agent for Ln-NPs to enhance their biocompatibility and chemical and colloidal stability. Specifically, Er3+/Yb3+ co-doped NaGdF4 Ln-NPs were modified with GA, followed by their characterization with respect to upconversion properties and in vitro as well as in vivo toxicity. Herein, widely used ligand-free and polyacrylic acid (PAA)-capped Ln-NPs were used as reference materials. Importantly, the GA-modified Ln-NPs exhibited superior stability in aqueous and biologically relevant media, as well as relatively lower cytotoxicity across multiple cell lines, including U-87 MG, HEPG2, and J774A.1. In vivo studies using zebrafish embryos confirmed the minimal toxicity of GA-capped Ln-NPs. Despite overall low non-specific cellular uptake, hyperspectral imaging and inductively coupled plasma mass spectrometry confirmed the colocalization of the Ln-NPs as a function of their surface chemistry in both cell models and zebrafish. The results suggest GA as an effective surface-stabilizing agent for Ln-NPs, paving the way for future functionalization with targeting agents.

Solid-state self carbo-passivation for refurbishing colloidal dispersity of catalytic silica nanoreactors.

Silica-based nanostructures are among the most utilized materials. However, a persistent challenge is their irreversible agglomeration upon drying and heat treatments, restricting their homogeneous colloidal re-dispersion - a mandatory requirement for diverse bio-applications. We address this bottleneck by developing a self carbo-passivation (SCP) strategy: silica nanoparticles (NPs), pre-included with the catalytic metal precursors and organosilanes undergo in vacuo thermochemical conversion with highly controlled interior-to-surface segregation of nanometer-scale "carbonaceous skin patches". This self-generated inert passivate shielding phenomenon at the individual NP level completely inhibits interparticle cross-linking, stopping chemical agglomeration and enhancing colloidal stability. By SCP, we synthesized silica-based magnetic-catalytic nanoreactors for magnetic field-induced catalysis inside living cells, by benefitting from the convenient high colloidal stability in bio-media, easy endocytosis and protective accessibility to the catalytic site in the complex bio-environment. The present work demonstrates deep mechanistic insight into unexplored solid-state nanoscopic chemical passivation phenomena, dramatically influencing NP surface characteristics, playing a critical role in solution-based applications.

Intraperitoneal versus intravenous administration of Flamma®-conjugated PEG-alendronate-coated upconversion nanoparticles in a mouse pancreatic cancer model.

Pancreatic cancer is one of the most common forms of malignant disease with a poor survival prognosis. Currently, nanomedicine holds great promise for targeted diagnosis and treatment of this cancer, which also reduces toxic side effects. In this work, we prepared PEG-coated monodisperse upconversion nanoparticles (UCNPs) with a conjugated Flamma® fluorescent dye for imaging and detection of particle distribution in vivo. We performed a thorough physicochemical characterization of the particles and determined their colloidal and chemical stability in several aqueous media such as water, PBS, Dulbecco's modified Eagle's medium and artificial lysosomal fluid. Luminescence resonance energy transfer from the emission of UCNPs as a donor to the Flamma® as an acceptor was confirmed. Intraperitoneal versus intravenous administration was then compared in terms of biodistribution of particles in various organs in the orthotopic mice pancreatic cancer model. The intraperitoneal route was preferred over the intravenous one, because it significantly increased the accumulation of particles in the tumor tissue. These new UCNP@Ale-PEG-Flamma® nanoparticles are thus promising for new treatment avenues for pancreatic cancer.

Extraction of Protein-Enriched Fractions from Sunflower and Hemp Seeds: Composition and Colloidal Stability of Less Refined Fractions as a Function of Initial pH

Extraction of Protein-Enriched Fractions from Sunflower and Hemp Seeds: Composition and Colloidal Stability of Less Refined Fractions as a Function of Initial pH

Chitosan-modified polymeric nanoparticles for the nose-to-brain drug delivery of paroxetine: an in vitro and in vivo evaluation.

This work focuses on the development of PLGA nanoparticles and their surface modification by chitosan to enhance the mucoadhesive properties and colloidal stability for intranasal delivery. Chitosan-coated paroxetine-loaded PLGA nanoparticles (PAR-CS-PLGA-NPs) were developed and characterized along with in vitro and in vivo evaluation. Particle size of 181.8 nm with a zeta potential of 36.3 mV was obtained. Entrapment efficiency % and drug loading % were 87.5% and 13.4%, respectively. TEM, FTIR, and DSC were also performed. In vitro drug release studies were conducted in phosphate buffered saline (pH 7.4) and simulated nasal fluid (pH 5.5), and sustained release was found until 72 h. Cellular assays on mammalian cells depicted the cell viability to be >60% even at the maximum concentration of PAR-CS-PLGA-NPs and showed significantly higher uptake than PLGA-NPs. Histopathological studies on the nasal epithelium showed no damage or inflammation when treated with PAR-CS-PLGA-NPs. In vivo studies were performed using Swiss albino mice to estimate the drug biodistribution after intranasal delivery of PAR-CS-PLGA-NPs. A significantly increased drug concentration was observed in the mouse brains (p < 0.05). Pharmacodynamics studies of the PAR-CS-PLGA-NPs were carried out by forced swimming test and locomotor activity test, demonstrating improved behavioral analysis parameters (p < 0.05). Thus, intranasal delivery of paroxetine-loaded mucoadhesive chitosan-coated PLGA nanoparticles could be potentially used for the treatment of depression.

Topical siRNA therapy of diabetic-like wound healing.

Non-healing wounds are a serious complication in diabetic patients. One of the detrimental factors contributing to limited wound healing is the accumulation of metalloproteinase-9 (MMP-9) in the wound. Selective inhibition of MMP-9 is one of the established therapeutic targets for diabetic wound healing. Here, a functional and biocompatible wound dressing is developed to enable a controlled release of a traceable vector loaded with the antisense siRNA against MMP-9 in the wound. The dressing consists of degradable polymer nanofibers embedded with a vector nanosystem - polymer-coated fluorescent nanodiamonds optimized for the binding of siRNA and colloidal stability of nanodiamond-siRNA complexes in a physiological environment. The developed dressing is tested on murine fibroblasts and also applied to wounds in a diabetic murine model to evaluate its suitability in terms of in vivo toxicity, biological efficacy, and handling. The treatment results in significant local inhibition of MMP-9 and a shortening of the wound healing time. The scar formation in treated diabetic-like mice becomes comparable with that in non-treated diabetes-free mice. Our results suggest that the application of our biocompatible dressing loaded with a non-toxic vector nanosystem is an effective and promising approach to gene therapy of non-healing wounds.

Effect of flowrate on the size segregation of magnetic nanoparticles by using continuous flow magnetic separator

Magnetic Nanoparticles (MNPs) possess significant potential across various sectors due to their versatility. However, specific MNP sizes are crucial for effective utilization. Traditional methods for synthesizing monodispersed MNPs are often expensive, complex, or environmentally harmful. This study proposes the effect of flow rate on the size segregation of MNPs using a continuous flow low gradient magnetic separator (CFLGMS). To produce MNPs that are monodispersed, firstly, MNPs undergo functionalization with the polyelectrolyte, poly (sodium 4-styrene sulfonate) (PSS), to enhance colloidal stability. Employing PSS molecules as splicing agents effectively inhibits MNP aggregation. To further enhance the monodispersity of MNPs, continuous flow is facilitated by configuring three separator columns in series, with permanent magnets (NdFeB) attached to the sides. As larger MNPs exhibit stronger magnetic field attraction, resulting in their capture by magnets first, followed by smaller MNPs, and finally the smallest ones. Consequently, MNPs captured in Column 1 possess the largest size, while those in Column 3 have the smallest size. Additionally, this paper investigates the impact of solution flowrate on size segregation efficiency. By varying the solution flow rate (10 mL/min, 15 mL/min, and 20 mL/min), it is found that the performance of the size segregation system is higher under the lower solution flowrate.

Formation of water-in-water emulsions and microgels in nonionic surfactant+gelatin aqueous mixtures.

Water-in-water (W/W) emulsions can be obtained when two water-soluble components are mutually immiscible. The scientific literature on W/W emulsions focuses on polymer-polymer mixtures, with only a few reports on polymer-salt systems, and no documented cases involving polymer-surfactant mixtures. Our hypothesis was that by lowering the cloud temperature of a surfactant through the addition of a polymer, phase segregation into two immiscible aqueous solutions could enable the formation of W/W emulsions. The system composed of an ethoxylated triglyceride surfactant (Kolliphor ELP) and gelatin was selected. The effect of gelatin on the surfactant's cloud temperature was assessed. Water-in-water (W/W) emulsions were prepared by stirring biphasic mixtures at temperatures above gelatin's gelation point. Gelatin microgels were formed by cooling down gelatin-in-Kolliphor W/W emulsions. Mucin particles were incorporated to improve the colloidal stability of these emulsions and genipin, a natural reagent, was added to produce crosslinked microgels. The addition of gelatin lowered the cloud temperature of the surfactant, resulting in the formation of two aqueous phases: a surfactant-rich solution and a gelatin-rich solution, which enabled the preparation of W/W emulsions. Chemically crosslinked microgels were successfully obtained by cooling down gelatin-in-surfactant emulsions, crosslinking with genipin and stabilized with mucin microparticles. To the best of our knowledge, this is the first report of W/W emulsions based on polymer-surfactant mixtures, unlike most W/W emulsions reported in the literature, which rely on immiscibility between two polymers in aqueous solutions.

Facile construction of polyoxometalate-polymer hybrid nanoparticles with pH/redox dual-responsiveness.

Responsive nanomaterials have emerged as promising candidates for advanced drug delivery systems (DDSs), offering the potential to precisely target disease sites and enhance treatment efficacy. To fulfil their potential, such materials need to be engineered to respond to specific variations in biological conditions. In this work, we present a series of pH/redox dual-responsive hybrid nanoparticles featuring an amphiphilic shell polymer and a pH-responsive core polymer. These nanoparticles incorporate a polyoxometalate (POM), specifically the cobalt(iii)-substituted borotungstate ([BIIIW11O39CoIII]6-), loaded through coordination chemistry between the encapsulated CoIII ions of the POM and pyridyl functional groups on the core polymer. The resulting hybrid nanoparticles show potential for controlled release with excellent stability at physiological pH, and efficient particle disassembly in response to the combination of pH and redox stimuli. Disassembly is proposed to occur following a two step mechanism. Structural rearrangement of the nanoparticle occurs on acidification followed by destabilization of the coordination bond between the polyanion and the pyridyl functionality in the core polymer following reduction. In this system, the POM acts in a novel role as a redox active structural cross-linker. These hybrid dual-responsive nanoparticles, featuring superior colloidal stability under extracellular conditions and controllable disintegration in response to the dual stimuli of acidic pH and redox conditions, provide a novel platform for the controlled intracellular release of therapeutics.

Portfolio of colloidally stable gold-gold sulfide nanoparticles and their use in broad-band photoacoustic imaging.

There is an increasing interest in non-invasive photoacoustic imaging and hence demand for non-toxic, stable, optical solid absorbers, particularly in the visible and near-infrared regions enabling deep tissue penetration. The most popular gold nanorods (GNR) suffer from cumbersome synthesis with poor reproducibility and stability under moderate laser exposure. Recently, a new class of nanoparticle, gold-gold sulfide (GGS), was recognized to have strong NIR absorption but lack colloidal stability. Here, we successfully synthesized a portfolio of aqueous GGS nanoparticles (NP) with excellent stability through a one-step, reproducible synthesis: Anionic, cationic, and protein-coated GGS NPs were obtained by using 3-mercaptopropionic acid (3MPA), branched poly(ethyleneimine) (bPEI) and bovine serum albumin (BSA) as a coating. All GGS NPs comprise small (<10 nm) and large anisotropic (>30 nm) morphologies and display two absorption bands centered at 530-540 nm and 800-900 nm. The photoacoustic activity (PA) of GGS NPs in solution at the visible (532 nm) and NIR (800 nm) region is similar and independent of the coating. Remarkably, they outperformed the spherical gold NPs and performed comparable to GNRs. In vitro PA microscopy images recorded with visible and NIR lasers revealed that GGS NPs are successfully internalized by triple-negative MDA-MB-231 breast cancer cells, used for the proof of principle. A coating-dependent intracellular PA signal in favor of GGS-3MPA was observed. The weakest signal was obtained with the GGS-BSA, indicating a low cellular uptake. These stable, aqueous GGS NPs emerge as promising candidates for broad-band PAI and further biomedical applications.

Taylor dispersion analysis and release studies of β-carotene-loaded PLGA nanoparticles and liposomes in simulated gastrointestinal fluids.

β-Carotene (βC), a natural carotenoid, is the most important and effective vitamin A precursor, known also for its antioxidant properties. However, its poor water solubility, chemical instability, and low bioavailability limit its effectiveness as an orally delivered functional nutrient. Nanoparticle encapsulation improves βC's bioaccessibility by enhancing its stability and solubility. This study compares two formulations, i.e. βC-loaded poly(lactic-co-glycolic acid) (PLGA) NPs and liposomes before and after exposure to simulated gastrointestinal fluids using various methods such as Taylor dispersion analysis (TDA), cryo-transmission electron microscopy, dynamic light scattering (DLS), and nanoparticle tracking analysis (NTA). TDA, a microfluidic technique, proved more effective than DLS and NTA in determining nanoparticle size in simulated gastrointestinal fluids. This highlights TDA's potential for assessing nanoparticle colloidal stability in simulated gastro-intestinal fluids, crucial for evaluating encapsulated bioactives' bioavailability. High-performance liquid chromatography (HPLC) revealed that PLGA nanoparticles incorporate and preserve βC more effectively during long-term storage compared to liposomes. Adding ascorbic acid significantly reduced degradation in simulated gastrointestinal fluids. Release studies showed that liposomes released 52% of βC after 36 hours, while PLGA nanoparticles released only 9% over 168 hours. These results provide valuable insights for selecting an appropriate βC nanocarrier for oral delivery based on desired release rates.

Understanding recycling agent modification mechanisms through rheological and compositional impacts

ABSTRACT This study utilised rheological and compositional measures to enhance the understanding of asphalt recycling agent (RA) modification mechanisms. Three types of RA products were evaluated: re-refined engine oil bottom (REOB)-based, vacuum gas oil (VGO), and triglyceride and fatty acids from bio-oil (TF). The efficacy of the products was evaluated by comparing the composition and rheology of recycled binder blends containing the additives to a virgin binder and blends of virgin and recycled binder. The findings indicate that RAs can modify recycled binder blends through three mechanisms: (a) softening by adding saturates and decreasing colloidal stability, (b) replenishing by adding aromatics to replace those lost to oxidation, and (c) emulsifying asphaltene micelles by adding resins. Rheological analysis of modulus and relaxation indicators effectively distinguished softeners. SARA (saturates, aromatics, resins, and asphaltenes) and Fourier Transform Infrared (FTIR) spectroscopy analyses differentiated replenishers from emulsifiers. Replenishers contained aromatics. Conversely, emulsifiers contained resins and exhibited FTIR peaks corresponding to polar compounds. The TF additives evaluated functioned as emulsifiers, while the VGO acted as a replenisher. The REOB-based additives functioned as softeners. Consistent with previous studies, the presence of REOB was detectable through calcium, copper, and zinc measurements obtained from X-ray fluorescence (XRF) spectroscopy.

Мониторинг подлинности и качества концентрированного виноградного сусла

The Russian wine industry permits the use of concentrated grape must. Due to its shortage on the market, it often becomes subject to adulteration. The article introduces a comprehensive system for assessing the quality of concentrated grape must that prevents adulteration of semi-dry and semi-sweet wines. The research featured 446 samples of fresh and concentrated grape must, commercial preparations of concentrated white grape must, and sugar or glucose-fructose syrups. The method of high-performance liquid chromatography made it possible to identify the profile of organic acids and sugars. After introducing authentic concentrated grape must, the samples were tested for colloidal turbidity and crystalline destabilization. The authentic samples retained the chemical composition of the original grape variety, as evidenced by such authenticity markers as pH, disaccharide content, tartaric and malic acids, and glucose-fructose index. In the adulterate samples, these values did not fit the standard limits. The experiment involved 179 samples of commercial preparations: 21% proved to be mixes of authentic must with other products; 9% proved to be syrup substitutes, and 1% was concentrated apple juice. Authentic concentrated must aggravated the trend to colloidal opacity (17%) and crystalline destabilization (13%); a combination of both trends occurred in 13%. Low-quality preparation of fresh grape must before vacuuming increased the content of high- molecular components, tartrate anions, and potassium cations in the concentrated product. The following two-step assessment of concentrated grape must quality made it possible to adopt a rational technological solution: I – confirming the grape origin; II – assessing the effect of the authentic product on the colloidal and crystalline stability of wine. This protocol demonstrated a good potential for ensuring the authenticity and bottling stability of semi-dry and semi-sweet wines.