Experimental methods in chemical engineering: Zeta potential

Metal-organic framework-derived Se-blended ZrO2 with a nitrogen-doped carbon heterostructure for electrocatalytic overall water splitting

Designing low cost, highly active and efficient non-noble metal bifunctional electrocatalysts with remarkable operational reliability for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is indispensable for large-scale water electrolysis and the development of clean energy conversion technologies. Herein, we decorated a two-dimensional (2D) selenium-blended zirconium dioxide (Se-ZrO2) on the surface of a nitrogen-doped carbon heterostructure (Se-ZrO2@NC), which was derived from Zr-metal-organic frameworks (Zr-MOFs), and loaded it on a stainless-steel mesh electrode. Accordingly, phenomenal electrocatalytic performance was observed for the Se-ZrO2@NC-loaded electrode with a minimum overpotential of 48 mV for the HER and 251 mV for the OER at 10 mA cm-2 current density in acidic and alkaline mediums, respectively. Moreover, a complete cell set up was constructed, where the OER and HER were studied at the anode and cathode, respectively, with a cell potential of 1.58 V to reach a current density of 10 mA cm-2 together with an exciting long-term stability of over 48 h. The developed Se-blended 2D transition metal dioxides on the 2D nitrogen-doped carbon heterostructure extended to a variety of catalytically active materials that would provide highly active and stable electrocatalysts for alkaline water splitting studies.

Quantification of the Surface Coverage of Gold Nanoparticles with Mercaptosulfonates Using Isothermal Titration Calorimetry (ITC)

This manuscript presents a comprehensive study on the quantification of modifier molecules adsorbed on gold nanoparticles (AuNPs) using two complementary techniques Ellman's method (UV-vis spectroscopy) and isothermal titration calorimetry (ITC). In this paper, we compare the feasibility of using the ITC technique and Ellman's method to study the interactions of mercaptosulfonate compounds (sodium mercaptoethanesulfonate, MES, and sodium mercaptoundecanesulfonate, MUS) with the surface of AuNPs of various sizes. The thermodynamic functions of the attachment of mercaptosulfonates to AuNPs were determined, revealing a linear relationship between the number of adsorbed molecules and the surface area of the nanoparticles. The amount of MES and MUS determined by Ellman's method (7 and 11 molecules per square nm, respectively) is more than twice that measured by the ITC technique (3 and 4 molecules per square nm, respectively). The slight differences in the adsorption of MES and MUS on the gold surface are due to differences in the carbon chain length of the ligand molecules. In the case of MES, the formation of the Au-S bond is the dominant stage of the adsorption process, whereas for MUS, the ordering process and self-assembly of molecules on the gold surface are dominant.

An enzymatic hydrolysis-based platform technology for the efficient high-yield production of cellulose nanospheres

This study evaluates the feasibility of using enzymatic technology to produce novel nanostructures of cellulose nanomaterials, specifically cellulose nanospheres (CNS), through enzymatic hydrolysis with endoglucanase and xylanase of pre-treated cellulose fibers. A statistical experimental design facilitated a comprehensive understanding of the process parameters, which enabled high yields of up to 82.7 %, while maintaining a uniform diameter of 54 nm and slightly improved crystallinity and thermal stability. Atomic force microscopy analyses revealed a distinct CNS formation mechanism, where initial fragmentation of rod-like nanoparticles and subsequent self-assembly of shorter rod-shaped nanoparticles led to CNS formation. Additionally, adjustments in process parameters allowed precise control over the CNS diameter, ranging from 20 to 100 nm, highlighting the potential for customization in high-performance applications. Furthermore, this study demonstrates how the process framework, originally developed for cellulose nanocrystals (CNC) production, was successfully adapted and optimized for CNS production, ensuring scalability and efficiency. In conclusion, this study emphasizes the versatility and efficiency of the enzyme-based platform for producing high-quality CNS, providing valuable insights into energy consumption for large-scale economic and environmental assessments.

Nymphaea alba leaf powder effectiveness in removing nisin from fermentation broth using docking and experimental analysis

The accumulation of nisin in the fermentation medium can reduce the process's productivity. This research studied the potential of Nymphaea alba leaf powder (NALP) as a hydrophobic biosorbent for efficient in-situ nisin adsorption from the fermentation medium by docking and experimental analysis. Molecular docking analysis showed that di-galloyl ellagic acid, a phytochemical compound found in N. alba, had the highest affinity towards nisin. Enhancements in nisin adsorption were seen following pre-treatment of NAPL with HCl and MgCl2. A logistic growth model was employed to evaluate the growth dynamics of the biosorption capacity, offering valuable insights for process scalability. Furthermore, optimization through Response Surface Methodology elucidated optimal nisin desorption conditions by Liebig's law of the minimum, which posits that the scarcest resource governs production efficiency. Fourier Transform Infrared (FTIR) spectroscopy pinpointed vital functional groups involved in biosorption. Scanning electron microscopy revealed the changing physical characteristics of the biosorbent after exposure to nisin. The findings designate NALP as a feasible adsorbent for nisin removal from the fermentation broth, thus facilitating its application in the purification of other biotechnological products based on growth and production optimization principles.

A Route to the Colorimetric Detection of Alpha-Fetoprotein Based on a Smartphone

Alpha-fetoprotein (AFP) is a key marker for early cancer detection and assessment. However, the current detection methods struggle to balance accuracy with the need for decentralized medical treatment. To address this issue, a new AFP analysis platform utilizing digital image colorimetry has been developed. Functionalized gold nanoparticles act as colorimetric agents, changing from purple-red to light gray-blue when exposed to different AFP concentrations. A smartphone app captures these color changes and calculates the AFP concentration in the sample. To improve detection accuracy, a hardware device ensures uniform illumination. Testing has confirmed that this system can quantitatively analyze AFP using colorimetry. The limit of detection reached 0.083 ng/mL, and the average accuracy reached 90.81%. This innovative method enhances AFP testing by offering portability, precision, and low cost, making it particularly suitable for resource-limited areas.

Rheological behavior and solution pH response properties of nanoparticle-regulated low surface tension systems

Regarding the rheological properties of fluids, certain nanoparticles can markedly modify the rheological behavior of low surface tension solutions by interacting with surfactant molecules. In this work, a low surface tension fluid with cetyltrimethylammonium chloride was prepared, and the silica nanoparticles were uniformly dispersed into it by ultrasonic dispersion. By adjusting the size, shape, and concentration of nanoparticles, the fluid behavior can be changed from Newtonian to non-Newtonian with finely tuned viscosity and characterized by a shear-thinning rheological behavior. In addition, this work explored how variations in environmental temperature and solution pH affect the rheological responses of the low surface tension suspension system. The experimental findings revealed that increasing the temperature substantially decreases the system's viscosity and induces a shear-thickening behavior. It is particularly significant that, under extreme pH conditions (either strongly acidic or alkaline), the viscosity of the nanoparticle suspensions was markedly enhanced at a particle concentration of 10 000 ppm. This interesting result coincided with a notable reduction in the zeta potential and an increase in the average particle size, suggesting an intensified aggregation of particles within the suspension system. A mechanism detailing the interaction between silica nanoparticles and surfactant micelles was proposed. This work indicates that the incorporation of nanoparticles into surfactant solutions offers a powerful approach to modulating fluid rheology across various conditions.

Antitoxin nanoparticles: design considerations, functional mechanisms, and applications in toxin neutralization

The application of nanotechnology has significantly advanced the development of novel platforms that enhance disease treatment and diagnosis. A key innovation in this field is the creation of antitoxin nanoparticles (ATNs), designed to address toxin exposure. These precision-engineered nanosystems have unique physicochemical properties and selective binding capabilities, allowing them to effectively capture and neutralize toxins from various biological, chemical, and environmental sources. In this review, we thoroughly examine their therapeutic and diagnostic potential for managing toxin-related challenges. We also explore recent advancements and offer critical insights into the design and clinical implementation of ATNs.

Effects of polystyrene nanoplastic size on zebrafish embryo development

Polystyrene nanoplastics (PS) require a comprehensive evaluation of their toxicity and potential risks to humans and the environment. The zebrafish model, a well-established animal model increasingly utilized for nanotoxicity assessments, was employed in this study. Our research aimed to explore the toxic effects of PS with sizes of 30, 100, 200, and 450 nm on zebrafish embryos. Exposure experiments were conducted on embryos at 4 h post-fertilization (hpf) using various concentrations of nanoparticles (20, 40, 60, 80, and 100 mg/L) until 96 hpf. Notably, PS ranging from 100 to 450 nm did not adversely affect zebrafish embryo development. However, PS with a size of 30 nm at a concentration of 100 mg/L resulted in embryo mortality but not embryonic malformations. Furthermore, our investigation confirmed the uptake of these nanoparticles by zebrafish larvae following the opening of their mouths, with the particles being found predominantly in the digestive system of the larvae. Additionally, 30 nm PS were found to significantly modulate the expression levels of genes associated with oxidative stress and apoptosis. These findings highlight the developmental impacts of 30 nm PS on zebrafish embryos, raising concerns about potential similar consequences in humans. Considering our findings, it is essential to encourage further research into the management and regulation of PS to mitigate their potential environmental and health impacts.

The influence of the chlorine atom on the biological activity of 2'-hydroxychalcone in relation to the lipid phase of biological membranes - Anticancer and antimicrobial activity

The study investigates the effect of the presence of a chlorine atom in the 2'-hydroxychalcone molecule on its interaction with model lipid membranes, in order to discern its potential pharmacological activity. Five chlorine derivatives of 2'-hydroxychalcone were synthesized and evaluated against liposomes composed of POPC and enriched with cationic (DOTAP) or anionic (POPG) lipids. The physicochemical properties of the compounds were initially simulated using SwissAdame software, revealing high lipophilicity (ilogP values: 2.79-2.90). The dynamic light scattering analysis of liposomes showed that chloro chalcones induce minor changes in the diameter of liposomes of different surface charges. Fluorescence quenching assays with a TMA-DPH probe demonstrated the strong ability of the compounds to interact with the lipid bilayer, with varying quenching capacities based on chlorine atom position. FTIR studies indicated alterations in carbonyl, phosphate, and choline groups, suggesting a transition area localization rather than deep penetration into the hydrocarbon chains. Additionally, dipole potential reduction was observed in POPC and POPC-POPG membranes, particularly pronounced by derivatives with a chlorine atom in the B ring. Antibacterial and antibiofilm assays revealed enhanced activity of derivatives with a chlorine atom compared to 2'-hydroxychalcone, especially against Gram-positive bacteria. The MIC and MBIC50 values showed increased efficacy in the presence of chlorine with 3'-5'-dichloro-2'-hydroxychalcone demonstrating optimal antimicrobial and antibiofilm activity. Furthermore, antiproliferative assays against breast cancer cell lines indicated higher activity of B-ring chlorine derivatives, particularly against MDA-MB-231 cells. In general, the presence of a chlorine atom in 2'-hydroxychalcone improves its pharmacological potential, with derivatives showing improved antimicrobial, antibiofilm, and antiproliferative activities, especially against aggressive breast cancer cell lines. These findings underscore the importance of molecular structure in modulating biological activity and highlight chalcones with a chlorine as promising candidates for further drug development studies.

Enhanced Dye Adsorption on Cold Plasma-Oxidized Multi-Walled Carbon Nanotubes: A Comparative Study

The oxidation of multi-walled carbon nanotubes (MWCNTs) using cold plasma was investigated for their subsequent use as adsorbents for the removal of dyes from aqueous solutions. The properties of MWCNTs after plasma modification and their adsorption capacities were compared with pristine and chemically oxidized nanotubes. The modification process employed a reactor where plasma was generated through dielectric barrier discharges (DBD) powered by high-voltage nanosecond pulses. Various modification conditions were examined, such as processing time and pulse voltage amplitude. The degree of oxidation and the impact on the chemistry and structure of the nanotubes was investigated through various physicochemical and morphological characterization techniques (XPS, BET, TEM, etc.). Maximum oxidation (O/C = 0.09 from O/C = 0.02 for pristine MWCNTs) was achieved after 60 min of nanopulsed-DBD plasma treatment. Subsequently, the modified nanotubes were used as adsorbents for the removal of the dye methylene blue (MB) from water. The adsorption experiments examined the effects of contact time between the adsorbent and MB, as well as the initial dye concentration in water. The plasma-modified nanotubes exhibited high MB removal efficiency, with adsorption capacity proportional to the degree of oxidation. Notably, their adsorption capacity significantly increased compared to both pristine and chemically oxidized MWCNTs (~54% and ~9%, respectively). Finally, the kinetics and mechanism of the adsorption process were studied, with experimental data fitting well to the pseudo-second-order kinetic model and the Langmuir isotherm model. This study underscores the potential of plasma technology as a low-cost and environmentally friendly approach for material modification and water purification.

Evaluation of Cytotoxicity and Metabolic Profiling of Synechocystis sp. Extract Encapsulated in Nano-Liposomes and Nano-Niosomes Using LC-MS, Complemented by Molecular Docking Studies

Liposomes and niosomes can be considered excellent drug delivery systems due to their ability to load all compounds, whether hydrophobic or hydrophilic. In addition, they can reduce the toxicity of the loaded drug without reducing its effectiveness. Synechocystis sp. is a unicellular, freshwater cyanobacteria strain that contains many bioactive compounds that qualify its use in industrial, pharmaceutical, and many other fields. This study investigated the potential of nano-liposomes (L) and nano-niosomes (N) for delivering Synechocystis sp. extract against cancer cell lines. Four different types of nanoparticles were prepared using a dry powder formulation and ethanol extract of Synechocystis sp. in both nanovesicles (N1 and N2, respectively) and liposomes (L1 and L2, respectively). Analysis of the formed vesicles using zeta analysis, SEM morphological analysis, and visual examination confirmed their stability and efficiency. L1 and L2 in this investigation had effective diameters of 419 and 847 nm, respectively, with PDI values of 0.24 and 0.27. Furthermore, the zeta potentials were found to range from -31.6 mV to -43.7 mV. Regarding N1 and N2, their effective diameters were 541 nm and 1051 nm, respectively, with PDI values of 0.31 and 0.35, and zeta potentials reported from -31.6 mV to -22.2 mV, respectively. Metabolic profiling tentatively identified 22 metabolites (1-22) from the ethanolic extract. Its effect against representative human cancers was studied in vitro, specifically against colon (Caco2), ovarian (OVCAR4), and breast (MCF7) cancer cell lines. The results showed the potential activities of the prepared N1, N2, L1, and L2 against the three cell lines, where L1 had cytotoxicity IC50 values of 19.56, 33.52, and 9.24 µg/mL compared to 26.27, 56.23, and 19.61 µg/mL for L2 against Caco2, OVCAR4, and MCF7, respectively. On the other hand, N1 exhibited IC50 values of 9.09, 11.42, and 2.38 µg/mL, while N2 showed values of 15.57, 18.17, and 35.31 µg/mL against Caco2, OVCAR4, and MCF7, respectively. Meanwhile, the formulations showed little effect on normal cell lines (FHC, OCE1, and MCF10a). All of the compounds were evaluated in silico against the epidermal growth factor receptor tyrosine kinase (EGFR). The molecular docking results showed that compound 21 (1-hexadecanoyl-2-(9Z-hexadecenoyl)-3-(6'-sulfo-alpha-D-quinovosyl)-sn-glycerol), followed by compounds 6 (Sulfoquinovosyl monoacylgycerol), 7 (3-Hydroxymyristic acid), 8 (Glycolipid PF2), 12 (Palmitoleic acid), and 19 (Glyceryl monostearate), showed the highest binding affinities. These compounds formed good hydrogen bond interactions with the key amino acid Lys721 as the co-crystallized ligand. These results suggest that nano-liposomes and nano-niosomes loaded with Synechocystis sp. extract hold promise for future cancer treatment development. Further research should focus on clinical trials, stability assessments, and pharmacological profiles to translate this approach into effective anticancer drugs.

Colorimetric detection of the potent carcinogen aflatoxin B1 based on the aggregation of L-lysine-functionalized gold nanoparticles in the presence of copper ions

L-lysine functionalized gold nanoparticles (AuNPs-Lys) have been widely used for the detection of worldwide interest analytes. In this work, a colorimetric assay for the detection of the carcinogen aflatoxin B1 (AFB1) based on the aggregation of AuNPs-Lys in the presence of copper ions was developed. For this purpose, AuNPs were synthesized in citrate aqueous solution, functionalized, and further characterized by UV-Vis, fluorescence, Fourier transform infrared spectroscopy (FTIR), nanoparticle tracking analysis (NTA), dynamic light scattering (DLS), and transmission electron microscopy (TEM). In general, AuNPS-Lys (~2.73 × 1011 particles) offered a clear colorimetric response in the presence of AFB1 and Cu2+ ions showing linearity in the range of 6.25 to 200 ng AFB1/mL, with a detection limit of 4.18 ng AFB1/mL via photometric inspection. Moreover, the performance of the proposed methodology was tested using the 991.31 AOAC official procedure based on monoclonal antibodies in maize samples artificially contaminated with AFB1. There was a good agreement between the measured AFB1 concentrations in both assays, the average recoveries for the colorimetric and immunoaffinity assays were between 91.2-98.4% and 96.0-99.2%, respectively. These results indicated that the colorimetric assay could be used as a rapid, eco-friendly, and cost-effective platform for the quantification of AFB1 in maize-based products.

Characterization Methods for Nanoparticle-Skin Interactions: An Overview

Research progresses have led to the development of different kinds of nanoplatforms to deliver drugs through different biological membranes. Particularly, nanocarriers represent a precious means to treat skin pathologies, due to their capability to solubilize lipophilic and hydrophilic drugs, to control their release, and to promote their permeation through the stratum corneum barrier. A crucial point in the development of nano-delivery systems relies on their characterization, as well as in the assessment of their interaction with tissues, in order to predict their fate under in vivo administration. The size of nanoparticles, their shape, and the type of matrix can influence their biodistribution inside the skin strata and their cellular uptake. In this respect, an overview of some characterization methods employed to investigate nanoparticles intended for topical administration is presented here, namely dynamic light scattering, zeta potential, scanning and transmission electron microscopy, X-ray diffraction, atomic force microscopy, Fourier transform infrared and Raman spectroscopy. In addition, the main fluorescence methods employed to detect the in vitro nanoparticles interaction with skin cell lines, such as fluorescence-activated cell sorting or confocal imaging, are described, considering different examples of applications. Finally, recent studies on the techniques employed to determine the nanoparticle presence in the skin by ex vivo and in vivo models are reported.

Buffer choice and pH strongly influence phase separation of SARS-CoV-2 nucleocapsid with RNA

The SARS-CoV-2 nucleocapsid (N) protein is crucial for virus replication and genome packaging. N protein forms biomolecular condensates both in vitro and in vivo in a process known as liquid-liquid phase separation (LLPS), but the exact factors regulating LLPS of N protein are not fully understood. Here, we show that pH and buffer choice have a profound impact on LLPS of N protein. The degree of phase separation is highly dependent on the pH of the solution, which is correlated with histidine protonation in N protein. Specifically, we demonstrate that protonation of H356 is essential for LLPS in phosphate buffer. Moreover, electrostatic interactions of buffer molecules with specific amino acid residues are able to alter the net charge of N protein, thus influencing its ability to undergo phase separation in the presence of RNA. Overall, these findings reveal that even subtle changes in amino acid protonation or surface charge caused by the pH and buffer system can strongly influence the LLPS behavior, and point to electrostatic interactions as the main driving forces of N protein phase separation. Further, our findings emphasize the importance of these experimental parameters when studying phase separation of biomolecules, especially in the context of viral infections where the intracellular milieu undergoes drastic changes and intracellular pH normally decreases.

Removal of Organic Dyes, Polymers and Surfactants Using Carbonaceous Materials Derived from Walnut Shells

A series of new granular carbonaceous adsorbents was prepared via single-stage physical and chemical activation of walnut shells. Their suitability for removing various types of organic pollutants (represented by dyes, surfactants and water-soluble polymers) from the liquid phase was assessed. The activation of the precursor was carried out with CO2 and H3PO4 using conventional heating. Activated biocarbons were characterized in terms of chemical composition, acidic-basic nature of the surface, textural and electrokinetic properties as well as thermal stability. Depending on the type of activating agent used during the activation procedure, the obtained biocarbons differed in terms of specific surface area (from 401 to 1361 m2/g) and the type of porous structure produced (microporosity contribution in the range of 45-75%). Adsorption tests proved that the effectiveness of removing organic pollutants from the liquid phase depended to a large extent on the type of prepared adsorbent as well as the chemical nature and the molecular size of the adsorbate used. The chemically activated sample showed greater removal efficiency in relation to all tested pollutants. Its maximum adsorption capacity for methylene blue, poly(acrylic acid), poly(ethylene glycol) and Triton X-100 reached the levels of 247.1, 680.9, 38.5 and 61.8 mg/g, respectively.

Hybridized quantum dot, silica, and gold nanoparticles for targeted chemo-radiotherapy in colorectal cancer theranostics

Multimodal nanoparticles, utilizing quantum dots (QDs), mesoporous silica nanoparticles (MSNs), and gold nanoparticles (Au NPs), offer substantial potential as a smart and targeted drug delivery system for simultaneous cancer therapy and imaging. This method entails coating magnetic GZCIS/ZnS QDs with mesoporous silica, loading epirubicin into the pores, capping with Au NPs, PEGylation, and conjugating with epithelial cell adhesion molecule (EpCAM) aptamers to actively target colorectal cancer (CRC) cells. This study showcases the hybrid QD@MSN-EPI-Au-PEG-Apt nanocarriers (size ~65 nm) with comprehensive characterizations post-synthesis. In vitro studies demonstrate the selective cytotoxicity of these targeted nanocarriers towards HT-29 cells compared to CHO cells, leading to a significant reduction in HT-29 cell survival when combined with irradiation. Targeted delivery of nanocarriers in vivo is validated by enhanced anti-tumor effects with reduced side effects following chemo-radiotherapy, along with imaging in a CRC mouse model. This approach holds promise for improved CRC theranostics.

Biomedical behaviors of CuO/γ-alumina/chitosan nanocomposites: Scolicidal and apoptotic effects on hydatid cysts protoscolices

Hydatid cysts caused by Echinococcus granulosus are a serious health problem that requires effective treatment. This study aimed to evaluate the scolicidal and apoptotic effects of copper oxide (CuO) and gamma alumina (γ-Al2O3) with or without chitosan (Chit), using Rosmarinus officinalis extract and chemical methods on protoscolices (PSCs) in vitro. The nanomaterials (NMs) were characterized by FTIR, EDS, DLS, XRD, FESEM, PDI, and zeta potential (ZP). Scolicidal and apoptotic effects of NMs were tested against PSCs at different concentrations and exposure times. The CuO NPs showed the highest scolicidal effect (33.26 %) among all NMs at 1.6 mg/mL and 60 min, followed by phytosynthesized CuO/γ-Al2O3 NC (23.41 %). The chitosan-modified CuO/γ-Al2O3 NC and the chemically synthesized CuO/γ-Al2O3 NC had less effect. The CuO NPs and the phytosynthesized CuO/γ-Al2O3 NC also significantly increased the expression of the caspase-3 gene in the PSCs at 0.4 mg/mL, indicating the induction of apoptosis. In conclusion, this study suggests that the phytosynthesized CuO/γ-Al2O3 NC and the CuO NPs could be potential candidates for treating echinococcosis by killing the PSCs through apoptosis. Further studies are needed to verify the in vivo efficacy and toxicity of these NMs and to optimize their delivery and targeting systems.

Biogenic crocetin-crosslinked chitosan nanoparticles with high stability and drug loading for efficient radioprotection

The risk of radiation exposure increases with the development of nuclear energy and technology, and radiation protection receives more and more attention from public health and safety. However, the numerous adverse effects and low drug utilization limit the practical applications of radioprotective agents. In this study, we developed a biogenic crocetin-crosslinked chitosan nanoparticle with high stability and drug loading for efficient radioprotection. In detail, the nanoparticles were prepared using the natural antioxidant crocetin as a cross-linking reagent in amidation reactions of chitosan and mPEG-COOH. The nanoparticles exhibit a quick scavenging ability for common reactive oxygen species and reactive nitrogen in vitro. Meanwhile, cellular experiments demonstrate the good biocompatibility of the nanoparticles and the alleviation of radiation damage by scavenging reactive oxygen species, reducing apoptosis, and inhibiting DNA damage, etc. Importantly, the nanoparticles are effective in mitigating oxidative damage in major organs and maintaining peripheral blood cell content. In addition, they perform better radioprotective properties than free drug due to the significant extension of the blood half-life of crocetin in vivo from 10 min to 5 h. This work proposes a drug-crosslinking strategy for the design of a highly efficient radioprotective agent, which exhibits a promising prospect in the fields of nuclear emergency and public health.

Enzymatic Synthesis of α-Glucan Microparticles Using Amylosucrases from Bifidobacterium Species and Its Physicochemical Properties

α-Glucan microparticles (GMPs) have significant potential as high-value biomaterials in various industries. This study proposes a bottom-up approach for producing GMPs using four amylosucrases from Bifidobacterium sp. (BASs). The physicochemical characteristics of these GMPs were analyzed, and the results showed that the properties of the GMPs varied depending on the type of enzymes used in their synthesis. As common properties, all GMPs exhibited typical B-type crystal patterns and poor colloidal dispersion stability. Interestingly, differences in the physicochemical properties of GMPs were generated depending on the synthesis rate of linear α-glucan by the enzymes and the degree of polymerization (DP) distribution. Consequently, we found differences in the properties of GMPs depending on the DP distribution of linear glucans prepared with four BASs. Furthermore, we suggest that precise control of the type and characteristics of the enzymes provides the possibility of producing GMPs with tailored physicochemical properties for various industrial applications.

Microfluidic-based nanoemulsion of Ocimum basilicum extract: Constituents, stability, characterization, and potential biomedical applications for improved antimicrobial and anticancer properties

This paper reports on the findings from a study that aimed to identify and characterize the constituents of Ocimum basilicum extract using gas chromatography-mass spectrometry (GC-MS) analysis, as well as assess the physicochemical properties and stability of nanoemulsions formulated with O. basilicum extract. The GC-MS analysis revealed that the O. basilicum extract contained 22 components, with Caryophyllene and Naringenin identified as the primary active constituents. The nanoemulsion formulation demonstrated excellent potential for use in the biomedical field, with a small and uniform particle size distribution, a negative zeta potential, and high encapsulation efficiency for the O. basilicum extract. The nanoemulsions exhibited spherical morphology and remained physically stable for up to 6 months. In vitro release studies indicated sustained release of the extract from the nanoemulsion formulation compared to the free extract solution. Furthermore, the developed nanoformulation exhibited enhanced anticancer properties against K562 cells while demonstrating low toxicity in normal cells (HEK293). The O. basilicum extract demonstrated antimicrobial activity against Pseudomonas aeruginosa, Candida albicans, and Staphylococcus epidermidis, with a potential synergistic effect observed when combined with the nanoemulsion. These findings contribute to the understanding of the constituents and potential applications of O. basilicum extract and its nanoemulsion formulation in various fields, including healthcare and pharmaceutical industries. Further optimization and research are necessary to maximize the efficacy and antimicrobial activity of the extract and its nanoformulation. RESEARCH HIGHLIGHTS: This study characterized the constituents of O. basilicum extract and assessed the physicochemical properties and stability of its nanoemulsion formulation. The O. basilicum extract contained 22 components, with Caryophyllene and Naringenin identified as the primary active constituents. The nanoemulsion formulation demonstrated excellent potential for biomedical applications, with sustained release of the extract, low toxicity, and enhanced anticancer and antimicrobial properties. The findings contribute to the understanding of the potential applications of O. basilicum extract and its nanoemulsion formulation in healthcare and pharmaceutical industries, highlighting the need for further optimization and research.

d-α-tocopheryl polyethylene glycol 1000 succinate surface scaffold polysarcosine based polymeric nanoparticles of enzalutamide for the treatment of colorectal cancer: In vitro, in vivo characterizations

In this study, Enzalutamide (ENZ) loaded Poly Lactic-co-Glycolic Acid (PLGA) nanoparticles coated with polysarcosine and d-α-Tocopheryl polyethylene glycol 1000 succinate (TPGS) were prepared using a three-step modified nanoprecipitation method combined with self-assembly. A three-factor, three-level Box-Behnken design was implemented with Design-Expert® software to evaluate the impact of three independent variables on particle size, zeta potential, and percent entrapment efficiency through a numeric optimization approach. The results were corroborated with ANOVA analysis, regression equations, and response surface plots. Field emission scanning electron microscopy and transmission electron microscope images revealed nanosized, spherical polymeric nanoparticles (NPs) with a size distribution ranging from 178.9 ± 2.3 to 212.8 ± 0.7 nm, a zeta potential of 12.6 ± 0.8 mV, and entrapment efficiency of 71.2 ± 0.7 %. The latter increased with higher polymer concentration. Increased polymer concentration and homogenization speed also enhanced drug entrapment efficiency. In vitro drug release was 85 ± 22.5 %, following the Higuchi model (R2 = 0.98) and Fickian diffusion (n < 0.5). In vitro cytotoxicity assessments, including Mitochondrial Membrane Potential Estimation, Apoptosis analysis, cell cycle analysis, Reactive oxygen species estimation, Wound healing assay, DNA fragmentation assay, and IC50 evaluation with Sulforhodamine B assay, indicated low toxicity and high efficacy of polymeric nanoparticles compared to the drug alone. In vivo studies demonstrated biocompatibility and target specificity. The findings suggest that TPGS surface-scaffolded polysarcosine-based polymer nanoparticles of ENZ could be a promising and safe delivery system with sustained release for colorectal cancer treatment, yielding improved therapeutic outcomes.

Characterizing Aptamer Interaction with the Oncolytic Virus VV-GMCSF-Lact

Aptamers are currently being investigated for their potential to improve virotherapy. They offer several advantages, including the ability to prevent the aggregation of viral particles, enhance target specificity, and protect against the neutralizing effects of antibodies. The purpose of this study was to comprehensively investigate an aptamer capable of enhancing virotherapy. This involved characterizing the previously selected aptamer for vaccinia virus (VACV), evaluating the aggregation and molecular interaction of the optimized aptamers with the recombinant oncolytic virus VV-GMCSF-Lact, and estimating their immunoshielding properties in the presence of human blood serum. We chose one optimized aptamer, NV14t_56, with the highest affinity to the virus from the pool of several truncated aptamers and built its 3D model. The NV14t_56 remained stable in human blood serum for 1 h and bound to VV-GMCSF-Lact in the micromolar range (Kd ≈ 0.35 μM). Based on dynamic light scattering data, it has been demonstrated that aptamers surround viral particles and inhibit aggregate formation. In the presence of serum, the hydrodynamic diameter (by intensity) of the aptamer-virus complex did not change. Microscale thermophoresis (MST) experiments showed that NV14t_56 binds with virus (EC50 = 1.487 × 109 PFU/mL). The analysis of the amplitudes of MST curves reveals that the components of the serum bind to the aptamer-virus complex without disrupting it. In vitro experiments demonstrated the efficacy of VV-GMCSF-Lact in conjunction with the aptamer when exposed to human blood serum in the absence of neutralizing antibodies (Nabs). Thus, NV14t_56 has the ability to inhibit virus aggregation, allowing VV-GMCSF-Lact to maintain its effectiveness throughout the storage period and subsequent use. When employing aptamers as protective agents for oncolytic viruses, the presence of neutralizing antibodies should be taken into account.

Effect of Temperature and Alkali Solution to Activate Diethyl Carbonate for Improving Rheological Properties of Modified Hydroxyethyl Methyl Cellulose

The applications of cellulose ethers in the petroleum industry represent various limitations in maintaining their rheological properties with an increase in both concentration and temperature. This paper proposed a new method to improve the rheological properties of hydroxyethyl methyl cellulose (HEMC) by incorporating diethyl carbonate (DEC) as a transesterification agent and alkali base solutions. Fourier transform infrared (FTIR) analysis confirmed the grafting of both composites onto the HEMC surface. The addition of sodium hydroxide (NaOH) improved the stability of the polymeric solution as observed from ζ-potential measurement. Shear viscosity and frequency sweep experiments were conducted at concentrations of 0.25-1 wt % at ambient and elevated temperatures ranging from 80-110 °C using a rheometer. In the results, the increase in viscosity at specific times and temperatures indicated the activation of DEC through the saponification reactions with alkali solutions. All polymeric solutions exhibited shear-thinning behavior and were fitted well by the Cross model. NaOH-based modified solution exhibited low shear viscosity compared to the DEC-HEMC solution at ambient temperature. However, at 110 °C, its viscosity exceeded that of the DEC-HEMC solution due to the activation of DEC. In frequency sweep analysis, the loss modulus (G″) was greater than the storage modulus (G') at lower frequencies and vice versa at higher frequencies. This signifies the viscoelastic behavior of modified solutions at 0.50 wt % and higher concentrations. The flow point (G' = G″) shifted to a low frequency, indicating the increasing dominance of elastic behavior with the rising temperature. At 110 °C, the NaOH-based modified solution exhibited both viscous and elastic behavior, confirming the solution's thermal stability and flowability. In conclusion, modified HEMC solution was found to be effective in controlling viscosity under ambient conditions, enhancing solubility, and improving thermal stability. This modified composite could play a significant role in optimizing viscoelastic properties and fluid performance under challenging wellbore conditions.

Synthesis and Bioapplication of Emerging Nanomaterials of Hafnium

A significant amount of progress in nanotechnology has been made due to the development of engineered nanoparticles. The use of metallic nanoparticles for various biomedical applications has been extensively investigated. Biomedical research is highly focused on them because of their inert nature, nanoscale structure, and similar size to many biological molecules. The intrinsic characteristics of these particles, including electronic, optical, physicochemical, and surface plasmon resonance, that can be altered by altering their size, shape, environment, aspect ratio, ease of synthesis, and functionalization properties, have led to numerous biomedical applications. Targeted drug delivery, sensing, photothermal and photodynamic therapy, and imaging are some of these. The promising clinical results of NBTXR3, a high-Z radiosensitizing nanomaterial derived from hafnium, have demonstrated translational potential of this metal. This radiosensitization approach leverages the dependence of energy attenuation on atomic number to enhance energy-matter interactions conducive to radiation therapy. High-Z nanoparticle localization in tumor issue differentially increases the effect of ionizing radiation on cancer cells versus nearby healthy ones and mitigates adverse effects by reducing the overall radiation burden. This principle enables material multifunctionality as contrast agents in X-ray-based imaging. The physiochemical properties of hafnium (Z = 72) are particularly advantageous for these applications. A well-placed K-edge absorption energy and high mass attenuation coefficient compared to elements in human tissue across clinical energy ranges leads to significant attenuation. Chemical reactivity allows for variety in nanoparticle synthesis, composition, and functionalization. Nanoparticles such as hafnium oxide exhibit excellent biocompatibility due to physiochemical inertness prior to incidence with ionizing radiation. Additionally, the optical and electronic properties are applicable in biosensing, optical component coatings, and semiconductors. The wide interest has prompted extensive research in design and synthesis to facilitate property fine-tuning. This review summarizes synthetic methods for hafnium-based nanomaterials and applications in therapy, imaging, and biosensing with a mechanistic focus. A discussion and future perspective section highlights clinical progress and elaborates on current challenges. By focusing on factors impacting applicational effectiveness and examining limitations this review aims to support researchers and expedite clinical translation of future hafnium-based nanomedicine.

Chitosan Soft Matter Vesicles Loaded with Acetaminophen as Promising Systems for Modified Drug Release

Our study was designed to acquire, characterize and evaluate the biocompatibility of novel lipid vesicles loaded with acetaminophen (APAP) and coated with chitosan (CS). We investigated the in vitro and in vivo drug release kinetics from these systems, and we conducted assessments for both in vitro hemocompatibility and in vivo biocompatibility. For the in vivo biocompatibility evaluation, the mice were randomly divided into four groups of six animals and were treated orally as follows: control group: 0.1 mL/10 g body weight of double-distilled water; CS group: 0.1 mL/10 g body weight 1% CS solution; APAP group: 150 mg/kg body weight APAP; APAP-v group: 150 mg/kg body weight APAP-loaded lipid vesicles. The impact of APAP-v on various hematological, biochemical, and immune parameters in mice were assessed, and the harvested tissues were subjected to histopathological examination. The innovative formulations effectively encapsulating APAP within soft vesicles exhibited reasonable stability in solution and prolonged drug release in both in vitro and in vivo studies. The in vitro hemolysis test involving APAP-loaded vesicles revealed no signs of damage to red blood cells. The mice treated with APAP-v showed neither significant variances in hematological, biochemical, and immune parameters, nor structural changes in the examined organ samples, compared to the control group. APAP-v administration led to prolonged drug release. We can conclude that the APAP-v are innovative carrier systems for modifying drug release, making them promising candidates for biomedical applications.

Amino-Functionalized Zirconium-Based Metal-Organic Frameworks as Bifunctional Nanomaterials to Treat Bone Tumors and Promote Osteogenesis

Bone tumor patients often encounter challenges associated with cancer cell residues and bone defects postoperation. To address this, there is an urgent need to develop a material that can enable tumor treatment and promote bone repair. Metal-organic frameworks (MOFs) have attracted the interest of many researchers due to their special porous structure, which has great potential in regenerative medicine and drug delivery. However, few studies explore MOFs with dual antitumor and bone regeneration properties. In this study, we investigated amino-functionalized zirconium-based MOF nanoparticles (UiO-66-NH2 NPs) as bifunctional nanomaterials for bone tumor treatment and osteogenesis promotion. UiO-66-NH2 NPs loading with doxorubicin (DOX) (DOX@UiO-66-NH2 NPs) showed good antitumor efficacy both in vitro and in vivo. Additionally, DOX@UiO-66-NH2 NPs significantly reduced lung injury compared to free DOX in vivo. Interestingly, the internalized UiO-66-NH2 NPs notably promoted the osteogenic differentiation of preosteoblasts. RNA-sequencing data revealed that PI3K-Akt signaling pathways or MAPK signaling pathways might be involved in this enhanced osteogenesis. Overall, UiO-66-NH2 NPs exhibit dual functionality in tumor treatment and bone repair, making them highly promising as a bifunctional material with broad application prospects.

The Emulsifying Properties, In Vitro Digestion Characteristics and Storage Stability of High-Pressure-Homogenization-Modified Dual-Protein-Based Emulsions

The droplet size, zeta potential, interface protein adsorption rate, physical stability and microrheological properties of high-pressure-homogenization (HPH)-modified, dual-protein-based whey-soy (whey protein isolate-soy protein isolate) emulsions containing different oil phase concentrations (5%, 10% and 15%; w/w) were compared in this paper. The in vitro digestion characteristics and storage stability of the dual-protein emulsions before and after HPH treatment were also explored. The results show that with an increase in the oil phase concentration, the droplet size and interface protein adsorption rate of the untreated dual-protein emulsions increased, while the absolute value of the zeta potential decreased. When the oil phase concentration was 10% (w/w), HPH treatment could significantly reduce the droplet size of the dual-protein emulsion, increase the interface protein adsorption rate, and improve the elasticity of the emulsion. Compared with other oil phase concentrations, the physical stability of the dual-protein emulsion containing a 10% (w/w) oil phase concentration was the best, so the in vitro digestion characteristics and storage stability of the emulsions were studied. Compared with the control group, the droplet size of the HPH-modified dual-protein emulsion was significantly reduced after gastrointestinal digestion, and the in vitro digestibility and release of free amino groups both significantly increased. The storage stability results show that the HPH-modified dual-protein emulsion showed good stability under different storage methods, and the storage stability of the steam-sterilized dual-protein emulsion stored at room temperature was the best. These results provide a theoretical basis for the development of new nutritional and healthy dual-protein liquid products.

Effective abatement of ammonium and nitrate release from sediments by biochar coverage

Inorganic forms of N from sediments and runoff water, among others, remain some of the key sources of pollution of water bodies. However, the release of NH4+-N from sediment to water can be effectively reduced by biochar coverage due to high adsorption capacity, unlike NO3-N, where biochar has a low affinity. The feasibility of biochar coverage to abate NO3--N release needs to be evaluated. This study collected four sediments from Lake Taihu (China). Three types of biochar pyrolyzed from ordinary wastes, coconut shell (coBC), algal and excess sludge, were prepared to cover them and were incubated for 90 days. Results showed that the terminal total nitrogen (TN) and NO3--N concentrations decreased from 5.35 to 2.31-3.04 mg/L, 3.05 to 0.34-1.11 mg/L, respectively. CoBC coverage showed the best performance for reducing NO3--N release flux from 26.99 ± 0.19 to 9.30 ± 0.02 mg/m2·d (63.6 %). Potential denitrifiers, such as Flavobacterium and Exiguobacterium, were enriched in the biochar-coverage layer, and the absolute abundance of N-related functional genes (narG, nirS, nosZ and anammox) was increased by 1.76-4.21 times (p < 0.05). Jar tests by 15N isotope labeling further indicated that biochar addition increased the denitrification and anammox rates by 53.5-83.4 %. Experiments combining exogenous organic‑carbon addition and 15N labeling demonstrated that biochar's key role was regulating organic matter's bioavailability. Analysis with partial least square path modeling (PLS-PM) implied biochar with higher adsorption enhanced the denitrification and anammox processes in sediments via modifying the niche with suitable DOC, TN, and pH. This study suggested that biochar coverage could effectively abate NO3--N release from sediments by affecting the denitrification and anammox processes.

Influence of drug molecular weight on self-assembly and intestinal permeation of polymer-based nanocarriers

For oral delivery, the physicochemical properties of nanocarriers are decisive factors for permeation through the intestinal epithelium. These properties are determined by the composition of the nanocarriers as well as by the process parameters during their self-assembly. For macromolecular drugs, there is still little understanding of the drug-polymer interactions during nanocarrier self-assembly and the effects on carrier properties. In this study, the effect of drug molecular weight on nanocarrier self-assembly, physicochemical properties of nanocarriers as well as their permeation across the intestinal epithelium was investigated. Our results show that the drug molecular weight impacts the physicochemical properties of nanocarriers. Further, the physicochemical properties of the nanocarriers, governed by the molecular weight of the drug, determine their permeation properties across the intestinal epithelium. Comparative in vitro and ex vivo studies revealed that intestinal absorption is dependent on both, the properties of the tissue as well as properties of the carrier system. In conclusion, the molecular weight of drug payload is a key factor determining the physiochemical properties of polymeric nanocarriers and is closely linked to their oral absorption. Using different preclinical models to evaluate intestinal permeation of nanocarriers allows for novel insights into key formulation properties governing oral bioavailability.

High-throughput screening to evaluate optimum coagulation conditions via colloidal stability analysis

Current methods of optimizing the coagulant dosage in wastewater treatment processes typically rely on the use of labor- and material-intensive jar testers, which are inadequate when coagulation processes require frequent adjustments due to variations in properties of the incoming feed. Analytical centrifuges (ACs) employ an integrated optics system that simultaneously monitors the position of the boundary between two separating phases in multiple samples of fairly low volumes (∼2 mL) - thus it was expected that ACs would be ideally suited to study the stability and settling kinetics of coagulation treatment processes. In this study, wastewater samples from a biogas generation facility (known as centrate) were collected in February 2022 (Batch A) and July 2022 (Batch B). A comprehensive screening of the treatment performance for Batch B was conducted at three pHs (5, 6, and 7) and nine concentrations of ferric chloride (0-500 mg-Fe3+/L) - it was found that the front-tracking profiles measured by the integrated optics system could be used to identify the minimal coagulation conditions needed to transition from slow to rapid settling. While the settling velocity was found to be well correlated with the instability index, a dimensionless number between 0 and 1 (where values closer to 1 indicate better separation), it was determined that the percentage of COD removal from the centrate samples increased up to an instability index of approximately 0.5 and then plateaued. Finally, it was found that the front-tracking profiles could be used to estimate the volume of sludge produced at various coagulation conditions. Thus, the results from this study establish ACs as an important screening tool for rapid evaluation of treatment performance while consuming minimal material and time - in this study, a total of 132 screening experiments were conducted using approximately ∼11 L of centrate and ∼6 hours of operator time.

The Impact of 2-Ketones Released from Solid Lipid Nanoparticles on Growth Modulation and Antioxidant System of Lactuca sativa

2-Ketones are signal molecules reported as plant growth stimulators, but their applications in vegetables have yet to be achieved. Solid lipid nanoparticles (SLNs) emerge as a relevant nanocarrier to develop formulations for the controlled release of 2-ketones. In this sense, seedlings of Lactuca sativa exposed to 125, 375, and 500 µL L-1 of encapsulated 2-nonanone and 2-tridecanone into SLNs were evaluated under controlled conditions. SLNs evidenced a spherical shape with a size of 230 nm. A controlled release of encapsulated doses of 2-nonanone and 2-tridecanone was observed, where a greater release was observed as the encapsulated dose of the compound increased. Root development was strongly stimulated mainly by 2-tridecanone and leaf area (25-32%) by 2-nonanone. Chlorophyll content increased by 15.8% with exposure to 500 µL L-1 of 2-nonanone, and carotenoid concentration was maintained with 2-nonanone. Antioxidant capacity decreased (13-62.7%) in L. sativa treated with 2-ketones, but the total phenol concentration strongly increased in seedlings exposed to some doses of 2-ketones. 2-Tridecanone strongly modulates the enzymatic activities associated with the scavenging of H2O2 at intra- and extracellular levels. In conclusion, 2-ketones released from SLNs modulated the growth and the antioxidant system of L. sativa, depending on the dose released.

Chitosomes Loaded with Docetaxel as a Promising Drug Delivery System to Laryngeal Cancer Cells: An In Vitro Cytotoxic Study

Current delivery of chemotherapy, either intra-venous or intra-arterial, remains suboptimal for patients with head and neck tumors. The free form of chemotherapy drugs, such as docetaxel, has non-specific tissue targeting and poor solubility in blood that deters treatment efficacy. Upon reaching the tumors, these drugs can also be easily washed away by the interstitial fluids. Liposomes have been used as nanocarriers to enhance docetaxel bioavailability. However, they are affected by potential interstitial dislodging due to insufficient intratumoral permeability and retention capabilities. Here, we developed and characterized docetaxel-loaded anionic nanoliposomes coated with a layer of mucoadhesive chitosan (chitosomes) for the application of chemotherapy drug delivery. The anionic liposomes were 99.4 ± 1.5 nm in diameter with a zeta potential of -26 ± 2.0 mV. The chitosan coating increased the liposome size to 120 ± 2.2 nm and the surface charge to 24.8 ± 2.6 mV. Chitosome formation was confirmed via FTIR spectroscopy and mucoadhesive analysis with anionic mucin dispersions. Blank liposomes and chitosomes showed no cytotoxic effect on human laryngeal stromal and cancer cells. Chitosomes were also internalized into the cytoplasm of human laryngeal cancer cells, indicating effective nanocarrier delivery. A higher cytotoxicity (p < 0.05) of docetaxel-loaded chitosomes towards human laryngeal cancer cells was observed compared to human stromal cells and control treatments. No hemolytic effect was observed on human red blood cells after a 3 h exposure, proving the proposed intra-arterial administration. Our in vitro results supported the potential of docetaxel-loaded chitosomes for locoregional chemotherapy delivery to laryngeal cancer cells.

Dynamic light scattering analysis of immune complexes in sera of rheumatoid arthritis patients

The size of circulating immune complexes (CICs) in rheumatoid arthritis (RA) could be an emerging criterion in disease diagnosis. This study analyzed size and electrokinetic potential of CICs from RA patients, healthy young adults, and RA patients age-matched controls aiming to establish their unique CIC features. Pooled CIC of 30 RA patients, 30 young adults, and 30 RA group's age-matched controls (middle-aged and oldеr healthy adults), and in vitro IgG aggregates from pooled sera of 300 healthy volunteers were tested using dynamic light scattering (DLS). Size distribution of CIC in healthy young adults exhibited high polydispersity. RA CIC patients and their age-matched control showed distinctly narrower size distributions compared with young adults. In these groups, particles clustered around two well-defined peaks. Particles of peak 1 were 36.1 ± 6.8 nm in RA age-matched control, and 30.8 ± 4.2 nm in RA patients. Particles of peak 2 of the RA age-matched control's CIC was 251.7 ± 41.2 nm, while RA CIC contained larger particles (359.9 ± 50.5 nm). The lower zeta potential of RA CIC, compared to control, indicated a disease-related decrease in colloidal stability. DLS identified RA-specific, but also age-specific distribution of CIC size and opened possibility of becoming a method for CIC size analysis in IC-mediated diseases.

Adjuvant action of needle-shaped BC microfibrils

Bacterial cellulose (BC) is an unbranched biopolymer produced by microorganisms and composed of glucopyranose units linked by β-1,4 bonds. This study investigates the adjuvant action of needle-shaped BC microfibrils (BCmFs) in vitro using bovine serum albumin (BSA) as a model antigen. BC produced by the static culture of Komagataibacter xylinus was then microparticled (1-5 μm) by acid hydrolysis and characterized using Dynamic Light Scattering and Scanning Electron Microscopy. Subsequently, Attenuated Total Reflectance-Fourier-Transform Infrared Spectroscopy, cytotoxicity, TNF-α (tumour necrosis factor-alpha) and IL-6 (interleukin-6) cytokine secretion, and cellular uptake of the BCmFs-BSA conjugate on the human monocyte cell line (U937) differentiated into macrophages were performed. The microfibrils were determined to be 1-5 μm in size, needle-shaped, with a zeta potential of - 32 mV. Their conjugation with the model antigen, BSA, was demonstrated by FTIR analysis. In the cytotoxicity assay, BCmFs-BSA in macrophage cells showed high viability (over 70%). Although the highest TNF-α cytokine level (113 pg/ml) was obtained with BCmFs-BSA (Bovine serum albumin) conjugate (500 µg/ml) and was statistically significant (p = 0.0001) compared to the positive control group (BSA-aluminium hydroxide), IL-6 cytokine levels were not statistically different from those in the control group as desired. It has been shown in macrophage-differentiated U937 cells that microbially synthesized BC in the form of needle-shaped microfibrils (BCmFs) has a high cellular uptake capacity and increases the immunogenicity of the antigen. These results demonstrate for the first time that BCmFs have the potential to serve as a vaccine adjuvant.

Co-exposure to nanoplastics and acetaminophen causes skeletal dysplasia and behavioral abnormalities in zebrafish

Nanoplastics (NPs) and acetaminophen (APAP) are thought to be common contaminants and are invariably detected in the environment. Despite the increasing awareness of their toxicity to humans and animals, the embryonic toxicity, skeletal development toxicity, and mechanism of action of their combined exposure have not been clarified. This study was performed to investigate whether combined exposure to NPs and APAP induces abnormal embryonic and skeletal development in zebrafish and to explore the potential toxicological mechanisms. All zebrafish juveniles in the high-concentration compound exposure group showed some abnormal phenomena such as pericardial edema, spinal curvature, cartilage developmental abnormality and melanin inhibition together with a significant downward trend in body length. Behavioral data also implicated that the exposure of APAP alone, as well as the co-exposure of NPs and APAP, caused a depression in the total distance, swimming speed and the maximum acceleration. Furthermore, real-time polymerase chain reaction analysis showed that compared with exposure alone, the expression level of genes related to osteogenesis, runx2a, runx2b, Sp7, bmp2b and shh was significantly reduced with compound exposure. These results suggest that the compound exposure of NPs and APAP has adverse impacts on zebrafish embryonic development and skeletal growth.

Effects of Ultra-High-Pressure Jet Processing on Casein Structure and Curdling Properties of Skimmed Bovine Milk

Ultra-high-pressure jet processing (UHPJ) is a new non-thermal processing technique that can be employed for the homogenization and the sterilization of dairy products. However, the effects on dairy products are unknown when using UHPJ for homogenization and sterilization. Thus, this study aimed to investigate the effects of UHPJ on the sensory and curdling properties of skimmed milk and the casein structure in skimmed milk. Skimmed bovine milk was treated with UHPJ using different pressures (100, 150, 200, 250, 300 MPa) and casein was extracted by isoelectric precipitation. Subsequently, the average particle size, Zeta potential, contents of free sulfhydryl and disulfide bonds, secondary structure, and surface micromorphology were all used as evaluation indicators to explore the effects of UHPJ on the structure of casein. The results showed that with an increase of pressure, the free sulfhydryl group content changed irregularly, while the disulfide bond content increased from 1.085 to 3.0944 μmol/g. The content of α-helix and random coil in the casein decreased, while the β-sheet content increased at 100, 150, 200 MPa pressure. However, treatment with higher pressures of 250 and 300 MPa had the opposite effect. The average particle size of the casein micelles first decreased to 167.47 nm and then increased up to 174.63 nm; the absolute value of Zeta potential decreased from 28.33 to 23.77 mV. Scanning electron microscopy analysis revealed that the casein micelles had fractured into flat, loose, porous structures under pressure instead of into large clusters. After being ultra-high-pressure jet-processed, the sensory properties of skimmed milk and its fermented curd were analyzed concurrently. The results demonstrated that UHPJ could alter the viscosity and color of skimmed milk, shortening curdling time from 4.5 h to 2.67 h, and that the texture of the curd fermented with this skimmed milk could be improved to varying degrees by changing the structure of casein. Thus, UHPJ has a promising application in the manufacture of fermented milk due to its ability to enhance the curdling efficiency of skimmed milk and improve the texture of fermented milk.

Improving electrochemical characteristics of plant roots by biochar is an efficient mechanism in increasing cations uptake by plants

Electrochemical properties of roots such as zeta potential and cation exchange capacity are important factors that play a critical role in the absorption of nutrients by plants. Adding biochar to the soil may improve the electrochemical properties of the roots and thereby increase absorption of nutrients by plants. Thus, this research was laid out under greenhouse condition to evaluate the possible effects of biochar addition to soil (25 g biochar kg^-1 soil) on changing electrochemical properties of roots, nutrients absorption, and growth parameters of safflower (with a deep root system) and mint (with a shallow root system) plants. Biochar noticeably increased pH and cation exchange capacity of soil, safflower and mint growth, calcium, magnesium and iron contents in roots and maximum sorption capacity of these nutrients by plant roots. Electrochemical measurements reveled that biochar application increases negative charges on root surface area (by about 30% and 36% in safflower and mint roots, respectively), cation exchange capacity of roots and root activity in both plants. On the other hand, biochar reduced zeta potential in plant roots (more negative potential). Reduction of zeta potential by biochar application were about 31% and 42% in safflower and mint roots, respectively. The cation-exchange groups (hydroxycinnamic acid + carboxyl groups) were increased due to biochar treatment by about 30% in safflower and 32% in mint roots. As an annual plant with deep roots, safflower roots had more functional groups, cation exchange capacity and root activity than mint plant in both biochar and control conditions. Results of this research showed that biochar not only adjusts physicochemical properties of rhizosphere, but also improves electrochemical specification of plant roots via increasing number of functional groups on root cell walls, which enhances maximum sorption capability of plant roots.

Theoretical determination of zeta potential for the variable charge soil considering the pH variation based on the Stern-Gouy double-layer model

Electrokinetic remediation (EKR) is a promising alternative for the contaminated soil with low hydraulic permeability. The nonlinearity of the electroosmotic flow (EOF) is mainly induced by the nonuniform variation of the pH and thus the zeta potential of the soil during the EKR process. The empirical relation between the zeta potential and the pH for kaolinite is currently applied to analyze the nonlinearity of the EOF. A new perspective for theoretical determination of the zeta potential for the variable charge soil is proposed in this study. The prediction model incorporates the pH, the valence and concentration of the electrolyte, and the temperature and permittivity of the solvent surrounding the clay particles. Satisfying agreement between the calculated and measured curves of zeta potential versus pH for three types of variable charge soil was achieved. This model would act as a useful tool to simulate the nonlinearity of the electroosmosis of the variable charge soil and provide guidance and precise control mechanism for maximizing the efficiency of the EOF.

Formation of Robust and Adaptive Biopolymers via Non-Covalent Supramolecular Interactions

Biomass-originated materials are the future's next-tier polymers. This work suggests improving mechanical and barrier properties of nature-sourced polymers using non-covalent supramolecular interactions. Polysaccharide chitosan is modified with amino acids via an esterification pathway using a systematic variation of hydrogen bond and aromatic domains (Degrees of substitution 12-49%). These controlled modifications improve stability due to non-covalent interactions, resulting in biopolymers with tailored thermal (decomposition temperature 232-275 °C), mechanical (Young's modulus 540-2667 MPa), and surface properties (roughness 4-40 nm). Chitosan and natural amino acids that are already manufactured at scale are purposely selected. The facile synthesis, controlled properties, stimuli-responsive potential, and inexhaustible origin of the raw materials provide the presented findings with the potential to become the method for the formation of high-performance biodegradable alternatives to petroleum-based polymers that can be used in packaging, food, agriculture, and medicine.

El-Tohamy M, A. Alhwaiti S. Advanced polymeric metal/metal oxide bionanocomposite using seaweed Laurencia dendroidea extract for antiprotozoal, anticancer, and photocatalytic applications

Background

Biosynthesized nanoparticles are gaining popularity due to their distinctive biological applications as well as bioactive secondary metabolites from natural products that contribute in green synthesis.

Methodology

This study reports a facile, ecofriendly, reliable, and cost-effective synthesis of silver nanoparticles (AgNPs), copper oxide nanoparticles (CuONPs), and polymeric PVP-silver-copper oxide nanocomposite using ethanol extract of seaweed Laurencia dendroidea and were evaluated for antiprotozoal, anticancer and photocatalytic potential. The nanostructures of the AgNPs, CuONPs, and polymeric PVP-Ag-CuO nanocomposite were confirmed by different spectroscopic and microscopic procedures.

Results

The UV-vis spectrum displayed distinct absorption peaks at 440, 350, and 470 nm for AgNPs, CuONPs, and polymeric Ag-CuO nanocomposite, respectively. The average particles size of the formed AgNPs, CuONPs, and Ag-CuO nanocomposite was 25, 28, and 30 nm, respectively with zeta potential values -31.7 ± 0.6 mV, -17.6 ± 4.2 mV, and -22.9 ± 4.45 mV. The microscopic investigation of biosynthesized nanomaterials revealed a spherical morphological shape with average crystallite sizes of 17.56 nm (AgNPs), 18.21 nm (CuONPs), and 25.46 nm (PVP-Ag-CuO nanocomposite). The antiprotozoal potential of green synthesized nanomaterials was examined against Leishmania amazonensis and Trypanosoma cruzi parasites. The polymeric PVP-Ag-CuO nanocomposite exerted the highest antiprotozoal effect with IC₅₀ values of 17.32 ± 1.5 and 17.48 ± 4.2 µM, in contrast to AgNPs and CuONPs. The anticancer potential of AgNPs, CuONPs, and polymeric PVP-Ag-CuO nanocomposite against HepG2 cancer cell lines revealed that all the nanomaterials were effective and the highest anticancer potential was displayed by PVP-Ag-CuO nanocomposite with IC₅₀ values 91.34 µg mL^-1 at 200 µg mL^-1 concentration. Additionally, PVP-Ag-CuO nanocomposite showed strong photocatalytic effect.

Conclusion

Overall, this study suggested that the biogenic synthesized nanomaterials AgNPs, CuONPs, and polymeric PVP-Ag-CuO nanocomposite using ethanol extract of seaweed L. dendroidea possesses promising antiprotozoal anticancer and photocatalytic effect and could be further exploited for the development of antiprotozoal and anticancer therapeutics agents.

Clarification of Surface Deswelling of Thermoresponsive Microgels by Electrophoresis

Although many investigations of thermoresponsive microgels have been reported, their surface properties, which are crucial in colloid science, are still not fully understood. In this study, microgels with surface-localized charged groups were synthesized by precipitation polymerization, and their electrophoretic behaviors were analyzed using a modified version of Ohshima's equation to obtain two surface properties of the soft particles: the softness parameter and the surface charge density. This systematic evaluation allows us to discuss the thermoresponsiveness of the overall microgels and their surfaces separately. Furthermore, the validity of the surface properties obtained from electrophoresis was verified by comparing them with the results of seeded emulsion polymerization in the presence of the microgels and the force-indentation curves obtained via high-speed atomic force microscopy (HS-AFM).

Euphorbia tirucalli latex loaded polymer nanoparticles: Synthesis, characterization, in vitro release and in vivo antinociceptive action

The encapsulation of drugs in micro and nanocarriers has helped to resolve mechanisms of cellular resistance and decrease drug side effects as well. In this study, poly(D,L-lactide-co-glycolide) (PLGA) was used to encapsulate the Euphol active substance-containing latex from Euphorbia tirucalli (E-latex). The nanoparticles (NP) were prepared using the solvent evaporation method and the physical and chemical properties were evaluated using spectrophotometric techniques. FTIR was used to prove the formation of the ester bond between the E-latex and PLGA-NP. The UV-Vis spectroscopic technique was used to show that more than 75% of the latex was encapsulated; the same technique was used to determine the release profile of the compound at different pH values, as well as determining the speed with which the process occurs through kinetic models, and it was observed that the best adjustments occurred for the Korsmeyer-Peppas model and the Higuchi model. The DLS technique was used to determine the diameter of the particles produced as well as their zeta potential (ZP). The sizes of the particles varied from 497 to 764 nm, and it was observed that the increase in E-latex concentration causes a reduction in the diameter of the NP and an increase in the ZP (-1.44 to -22.7 mV), due to more functional groups from latex film being adsorbed to the NPs surfaces. The thermogravimetric experiments exhibit the glass transition temperatures (Tg) that is appropriate for the use of formulated NPs as a stable drug delivery device before use. The in vivo activity of E-NPs (30 and 100 mg/Kg/p.o.) was tested against carrageenan-induced mechanical hypernociception. The data demonstrated a significantly antinociceptive effect for E-NPs, suggesting that E-latex nanoencapsulation preserved its desired properties.

Carboxymethyl-Dextran-Coated Superparamagnetic Iron Oxide Nanoparticles for Drug Delivery: Influence of the Coating Thickness on the Particle Properties

Carboxymethyl-dextran (CMD)-coated iron oxide nanoparticles (IONs) are of great interest in nanomedicine, especially for applications in drug delivery. To develop a magnetically controlled drug delivery system, many factors must be considered, including the composition, surface properties, size and agglomeration, magnetization, cytocompatibility, and drug activity. This study reveals how the CMD coating thickness can influence these particle properties. ION@CMD are synthesized by co-precipitation. A higher quantity of CMD leads to a thicker coating and a reduced superparamagnetic core size with decreasing magnetization. Above 12.5−25.0 g L−1 of CMD, the particles are colloidally stable. All the particles show hydrodynamic diameters < 100 nm and a good cell viability in contact with smooth muscle cells, fulfilling two of the most critical characteristics of drug delivery systems. New insights into the significant impact of agglomeration on the magnetophoretic behavior are shown. Remarkable drug loadings (62%) with the antimicrobial peptide lasioglossin and an excellent efficiency (82.3%) were obtained by covalent coupling with the EDC/NHS (N-ethyl-N′-(3-(dimethylamino)propyl)carbodiimide/N-hydroxysuccinimide) method in comparison with the adsorption method (24% drug loading, 28% efficiency). The systems showed high antimicrobial activity with a minimal inhibitory concentration of 1.13 µM (adsorption) and 1.70 µM (covalent). This system successfully combines an antimicrobial peptide with a magnetically controllable drug carrier.

Green Synthesis of Silver Nanoparticles for Preparation of Gelatin Films with Antimicrobial Activity

Silver nanoparticles were successfully synthesized using Thuja orientalis aqueous extract and AgNO3 as a precursor. UV-Vis showed a distinct absorption peak at 424 nm attributed to silver nanoparticles due to their surface plasmon resonance. Atomic absorption analysis reflected an increase in the concentration of nanoparticles in relation to the progress of the synthesis, obtaining a peak concentration value of 15.7 mg/L at 50 min. The FTIR spectra revealed the characteristic functional groups of phytomolecules involved in the silver-ion binding process, such as R-O-H (3335 cm-1) O=C-OH (2314 cm-1) and C-C=C (1450 cm-1). At 50 min, zeta potential showed the stability of the nanoparticles with the value of -21.73 mV. TEM micrographs revealed the formation of spherical nanoparticles with an average size of about 85.77 nm. Furthermore, films incorporated with nanoparticles exhibited a Tg from 66.42 °C to 73.71 °C and Tm at 103.31 °C. Films from the G22 formulation presented excellent antibacterial properties inhibiting the growth of Staphylococcus aureus. Thuja orientalis aqueous extract could be a low-cost, eco-friendly, and efficient reducing and capping agent for the synthesis of nanometric-sized Ag particles. Gelatin films with nanoparticles are expected to have high potential as an active food packaging system.

Temperature-Responsive Polysaccharide Microparticles Containing Nanoparticles: Release of Multiple Cationic/Anionic Compounds

Most drug carriers used in pulmonary administration are microparticles with diameters over 1 µm. Only a few examples involving nanoparticles have been reported because such small particles are readily exhaled. Consequently, the development of microparticles capable of encapsulating nanoparticles and a wide range of compounds for pulmonary drug-delivery applications is an important objective. In this study, we investigated the development of polysaccharide microparticles containing nanoparticles for the temperature-responsive and two-step release of inclusions. The prepared microparticles containing nanoparticles can release two differently charged compounds in a stepwise manner. The particles have two different drug release pathways: one is the release of nanoparticle inclusions from the nanoparticles and the other is the release of microparticle inclusions during microparticle collapse. The nanoparticles can be efficiently delivered deep into the lungs and a wide range of compounds are released in a charge-independent manner, owing to the suitable roughness of the microparticle surface. These polysaccharide microparticles containing nanoparticles are expected to be used as temperature-responsive drug carriers, not only for pulmonary administration but also for various administration routes, including transpulmonary, intramuscular, and transdermal routes, that can release multiple drugs in a controlled manner.