Hydrodynamic Size Distribution Research Articles

Road tunnel-derived coarse, fine and ultrafine particulate matter: physical and chemical characterization and pro-inflammatory responses in human bronchial epithelial cells

BackgroundTraffic particulate matter (PM) comprises a mixture of particles from fuel combustion and wear of road pavement, tires and brakes. In countries with low winter temperatures the relative contribution of mineral-rich PM from road abrasion may be especially high due to use of studded tires during winter season. The aim of the present study was to sample and characterize size-fractioned PM from two road tunnels paved with different stone materials in the asphalt, and to compare the pro-inflammatory potential of these fractions in human bronchial epithelial cells (HBEC3-KT) in relation to physicochemical characteristics.MethodsThe road tunnel PM was collected with a vacuum pump and a high-volume cascade impactor sampler. PM was sampled during winter, both during humid and dry road surface conditions, and before and after cleaning the tunnels. Samples were analysed for hydrodynamic size distribution, content of elemental carbon (EC), organic carbon (OC) and endotoxin, and the capacity for acellular generation of reactive oxygen species. Cytotoxicity and pro-inflammatory responses were assessed in HBEC3-KT cells after exposure to coarse (2.5–10 μm), fine (0.18–2.5 μm) and ultrafine PM (≤ 0.18 μm), as well as particles from the respective stone materials used in the pavement.ResultsThe pro-inflammatory potency of the PM samples varied between road tunnels and size fractions, but showed more marked responses than for the stone materials used in asphalt of the respective tunnels. In particular, fine samples showed significant increases as low as 25 µg/mL (2.6 µg/cm2) and were more potent than coarse samples, while ultrafine samples showed more variable responses between tunnels, sampling conditions and endpoints. The most marked responses were observed for fine PM sampled during humid road surface conditions. Linear correlation analysis showed that particle-induced cytokine responses were correlated to OC levels, while no correlations were observed for other PM characteristics.ConclusionsThe pro-inflammatory potential of fine road tunnel PM sampled during winter season was high compared to coarse PM. The differences between the PM-induced cytokine responses were not related to stone materials in the asphalt. However, the ratio of OC to total PM mass was associated with the pro-inflammatory potential.

Lipid nanoparticle formulations for optimal RNA-based topical delivery to murine airways

Introduction: Lipid nanoparticles (LNP) have been successfully used as a platform technology for delivering nucleic acids to the liver. To broaden the application of LNPs in targeting non-hepatic tissues, we developed LNP-based RNA therapies (siRNA or mRNA) for the respiratory tract. Such optimized LNP systems could offer an early treatment strategy for viral respiratory tract infections such as COVID-19.Methods: We generated a small library of six LNP formulations with varying helper lipid compositions and characterized their hydrodynamic diameter, size distribution and cargo entrapment properties. Next, we screened these LNP formulations for particle uptake and evaluated their potential for transfecting mRNA encoding green fluorescence protein (GFP) or SARS-CoV2 nucleocapsid-GFP fusion reporter gene in a human airway epithelial cell line in vitro. Following LNP-siGFP delivery, GFP protein knockdown efficiency was assessed by flow cytometry to determine %GFP+ cells and median fluorescence intensity (MFI) for GFP. Finally, lead LNP candidates were validated in Friend leukemia virus B (FVB) male mice via intranasal delivery of an mRNA encoding luciferase, using in vivo bioluminescence imaging.Results: Dynamic light scattering revealed that all LNP formulations contained particles with an average diameter of <100 nm and a polydispersity index of <0.2. Human airway epithelial cell lines in culture internalized LNPs with differential GFP transfection efficiencies (73–97%). The lead formulation LNP6 entrapping GFP or Nuc-GFP mRNA demonstrated the highest transfection efficiency (97%). Administration of LNP-GFP siRNA resulted in a significant reduction of GFP protein expression. For in vivo studies, intranasal delivery of LNPs containing helper lipids (DSPC, DOPC, ESM or DOPS) with luciferase mRNA showed significant increase in luminescence expression in nasal cavity and lungs by at least 10 times above baseline control.Conclusion: LNP formulations enable the delivery of RNA payloads into human airway epithelial cells, and in the murine respiratory system; they can be delivered to nasal mucosa and lower respiratory tract via intranasal delivery. The composition of helper lipids in LNPs crucially modulates transfection efficiencies in airway epithelia, highlighting their importance in effective delivery of therapeutic products for airways diseases.

Tunable Protein Adsorption by Zwitterionic Spherical Poly(CBAA) Brushes Prepared via Photoemulsion Polymerization

Zwitterionic polymer brushes are well-known as excellent hydrophilic and antifouling materials. However, they demonstrate a certain degree of adsorption for proteins and other substances in practical application, and little research has been conducted into this area. Herein, a facile and efficient approach was employed to prepare zwitterionic spherical polymer brushes, polystyrene-poly(2-carboxy-N,N-dimethyl-N-(3′-acrylamidopropyl) ethanaminium inner salt) brushes (PS–PCBAA brushes). Specifically, the preparation process consists of three steps. First, polystyrene (PS) nanospheres were synthesized via conventional emulsion polymerization, and then photoinitiator with terminal double bond was immobilized on the surface of the PS core by copolymerizing with styrene (PS@HMEM). Finally, zwitterionic polymer chains (PCBAA) were grafted onto the surface of PS@HMEM via photoemulsion polymerization. The hydrodynamic diameter and size distribution, morphology, and chemical composition of PS–PCBAA brushes were characterized. The interaction between PS–PCBAA brushes and proteins was investigated by turbidity and size change. The interaction between brushes and proteins was mainly affected by two factors: the electrostatic interaction between polymer chains and proteins, and the transition of zwitterionic polymers from a fouling polymer to a nonfouling polymer. This work provided a simple and environmentally friendly method for constructing zwitterionic materials that showed potential application in the controllable adsorption and desorption of proteins.

Synthesis, Characterization, and Biological Activity Evaluation of Magnetite-Functionalized Eugenol

This work reports the magnetite-functionalization and biological evaluation of eugenol by the co-precipitation method employed only Fe2+ under mild conditions and control from the amount of the incorporated magnetite. Magnetic nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), hydrodynamic size distribution (Zetasizer), and vibrating sample magnetometer (VSM). SEM images showed that EUG·Fe3O4 similar in shape to a nanoflower. The FTIR spectrum confirmed the presence of characteristic EUG and Fe3O4 bands in the EUG·Fe3O4 sample, the XRD analysis showed that the magnetite functionalization with eugenol slightly affected the Fe3O4 crystal structure, while the VSM measurements demonstrate that EUG·Fe3O4 1:1 shows a superparamagnetic behavior, suggesting small non-interacting particles. The in vitro safety profile and cytotoxicity of free eugenol, magnetite pristine, EUG·Fe3O4 1:1, EUG·Fe3O4 1:5, and EUG·Fe3O4 1:10 was investigated using human cell lines (keratinocytes and melanoma). The results demonstrate the high biocompatibility of EUG·Fe3O4 in HaCat cells and the greater specificity for the A375 cell line. Furthermore, the magnetite-functionalization with eugenol decreased the toxic effects of free eugenol on healthy cells. Antibacterial tests were performed in different bacterial strains. The experimental data showed that among the magnetic compounds, the microorganisms were only sensitive to treatment with EUG·Fe3O4 1:1. Regarding the antibiofilm activity assay, it can be observed that only the EUG·Fe3O4 caused a significant decrease in biomass when compared to the positive control. Finally, it can be concluded that EUG·Fe3O4 proves to be a potential candidate for future studies for drug delivery of cancer and bacterial infections treatments.

Litchi chinensis inspired nanoformulations: a synergy guided approach for unraveling promising cytotoxic attributes of metal and nonmetal conjugates.

In present study, diverse Litchi chinensis-mediated nanostructures in combination with 5-fluorouracil drug were fabricated viz. Au, Se, Ag, Ag-Se, Ag-Au, 5-FU Ag-Se and 5-FU Ag-Au with subsequent characterization and scrutinization of their anticarcinogenic capabilities. UV-Visible spectroscopic analysis confirmed the state transition for each precursor salt. XRD and transmission electron microscopy analysis revealed spherical/quasispherical nanostructures with monoclinic crystalline organization ranged between 18nm and 38nm. FTIR analysis revealed fabricated nanoparticles to be capped with various phytoconstituents. DLS and Zeta potential analysis of unloaded and drug-loaded bielemental nanoparticles (BNPs) showed comparatively large hydrodynamic particle size distribution and sufficient stability of nanoparticles. BNPs showed promising lethality concentrations for brine shrimp (LC50<2μg/ml) and antitumor (LC50<10μg/ml) assessments. These findings were in positive correlation with the antioxidant inhibitory concentrations IC50 (74.2-180.1μg/ml) of the tested entities. Ag-Se and Ag-Au were loaded with 5-FU (loading efficiency of 47%±1.14 and 25%±0.32, respectively) in light of their promising cytotoxic actions. All nanostructures showed profound hemocompatibility with maximum hemolytic activity as low as 2.4%. Highly significant difference (P<0.01) was observed in antineoplastic potentials of unloaded and 5-FU loaded BNPs against HepG2 and HT144, with most substantial IC50 for 5-FU Ag-Au (8.95±2.86μg/ml). 5-FU Ag-Au was identified as a significant inducer of DNA fragmentation with maximum relative tail moment (HepG2: 3.45±0.21) among all treatments.

Physical characterization of biomedical magnetic nanoparticles using multi-detector centrifugal field-flow fractionation

Abstract The unique magnetic properties of magnetic nanoparticles (MNP) combined with their small size already led to numerous medical applications. Accurate determination of their magnetic properties is a key requirement enquired by users, that is impeded by the ever-present distribution of MNP sizes. Field flow fractionation (FFF) techniques may help to overcome these limitations by first separating the particles before characterization. In this study, we demonstrate the use of centrifugal FFF coupled to online detectors for fractionation, structural, and magnetic characterization of MNP. The primary goal is to establish a reproducible centrifugal FFF (CF3) method for MNP fractionation We show that CF3 has the same capability as other FFF techniques in resolving the bimodal hydrodynamic size distribution present in the commercial MNP system Resovist® but is faster and more straightforward through its technical approach.

ZnAl hydrotalcites modified with nanocomposites nZVI–PAA for environmental remediation

Diffraction patterns of polyacrylic acid (PAA) encapsulated-(Fe)-modified ZnAl hydrotalcite (ZnAlH) showed the integration of Fe in the H lattice, resulting in a hybrid nanocomposite (Fe-PAA-ZnAlH), which was mainly verified with the characteristic shift in the 59–63° (2θ) region of the ZnAlH (110) reflection plane. The rise in the unit cell parameters (c and a ) as the Fe % incremented, denoted incorporation of Fe in the ZnAlH red. Nonetheless, changes in the immobilizer molecular weight (PAA MW) from 1250 kDa to 5.1 kDa did not cause a difference in the distance between layers (c parameter) but in the cation-cation separation ( a parameter), which meant that the nanoparticle was not located between layers, but in the lattice. The resulting band gap energies of the calcined hybrid nanocomposites were among 1.07–1.21 eV, which is an additional support of Fe +3 integration, suggesting insertion of Fe +3 3d orbitals between the valence and the conduction band of ZnO. Furthermore, nZVI were prepared through a pre-agglomeration reduction method, where COOH-groups were bound to metal cations. Initially, aqueous Fe +2 was bound to PAA [Fe +2 -PAA], then reduced to obtain enclosed hybrid (nZVI-PAA). Less stability and more aggregation were observed with the lower molecular weight PAA. Additionally, PAA dissociation caused by pH changes affected the clustering of the nZVI particles. At higher MW, the hydrodynamic diameter and size distribution become smaller and tighter, respectively, allowing a more monodispersed population with sphere shape and organized in core–shell beads chains.

Bioaccessibility and reactivity of alloy powders used in powder bed fusion additive manufacturing

Exposure to metal particles via the inhalation route unavoidably takes place at occupational settings during additive manufacturing of metals and alloys. This calls for investigations on possible adverse health effects. This study focuses on virgin and reused powders of three iron- and nickel-based alloy powders (316L, IN718, 18Ni300) widely used in additive manufacturing, and dust powder of 18Ni300 generated during laser melting. Investigations were performed from a physico-chemical and toxicological perspective assessing their bioaccessibility in artificial lysosomal fluid (ALF, simulating lung exposure to respirable particles), corrosion behavior, surface morphology and composition, microstructure, hydrodynamic size distribution in ALF, and in-vitro toxicity towards cultured human lung cells. Less than 1% of the powder mass was dissolved from the passive alloys (316L, IN718) under simulated physiological conditions (pH4.5, 37 °C, 24 h), whereas the 18Ni300 iron-nickel alloy showed an active behavior and dissolved completely. Reused powders of 18Ni300 and IN718 showed no, or only minor, differences in surface oxide composition, metal release pattern, and corrosion behavior compared with virgin powders. After reuse, the 316L powder showed an enrichment of manganese within the outermost surface, an increased corrosion current, increased amounts of released iron and an increased fraction of particles with ferritic microstructure, which increased the extent of particle aggregation. All powders showed low, or negligible, cytotoxic potency and reactive oxygen species formation. Powder bed fusion using laser melting can hence affect the chemical, physical, and surface properties of non-fused powders, which, if reused, could influence the properties of the printed part.

Effect of the magnetic field on the synthesis of colloidal silver and gold nanoparticles by laser ablation in bidestilated water

The effect of magnetic field of 0.3 T on the concentration, distribution of sizes in suspension and zeta potential of colloidal gold and colloidal silver nanoparticles, obtained by considering the pulsed laser ablation in double distilled water was studied. The magnetic field was transverse to the direction of incidence of the laser radiation and parallel to the surface of a submerged target. An Nd: YAG laser was used (1064 nm in wavelength, 10 ns in duration, repetition rate of 10 Hz and 37 mJ of energy) to ablate targets. The colloids were characterized by inductively coupled plasma optical emission spectroscopy, ultraviolet-visible spectroscopy, dynamic light scattering and zeta potential. Concentration analysis suggested that applying magnetic field of 0.3 T during nanoparticle synthesis leads to higher concentration. Applying magnetic field led to an eleven percent increase in the concentration of the colloid with gold nanoparticles and a five percent increase in the concentration of the colloidal silver nanoparticles. The absorption spectra suggested the presence of spherical nanoparticles. When analyzing the effect of the magnetic field on the hydrodynamic size distribution of the nanoparticles and the zeta potential of the colloids, no significant changes were evidenced. The magnetic confinement of the plasma induced by laser ablation caused changes in the characteristics of the colloids.

Sono-Biosynthesis and Characterization of AuNPs from Danube Delta Nymphaea alba Root Extracts and Their Biological Properties.

Root extracts from Danube Delta Nymphaea alba were used to prepare gold nanoparticles (AuNPRn) by reducing HAuCl4 at different pHs (6.4–8.4) using ultrasonic irradiation: an easy, cheap, eco-friendly and green approach. Their antibacterial and anticancer activities were evaluated against Staphylococcus aureus and Escherichia coli, and A2780 ovarian cancer cells, respectively. The AuNPRn were characterized concerning their phytoconstituents (polyphenols, flavonoids and condensed tannins) and gold content. All of the nanoparticles were negatively charged. AuNPRn exhibited a hydrodynamic size distribution ranging from 32 nm to 280 nm, with the larger nanoparticles being obtained with an Au/root extract ratio of 0.56, pH 7 and 10 min of sonication (AuNPR1), whereas the smallest were obtained with an Au/root extract ratio of 0.24, pH 7.8 and 40 min of sonication (AuNPR4). The TEM/SEM images showed that the AuNPRn had different shapes. The ATR-FTIR indicated that AuNPRn interact mainly with hydroxyl groups present in the polyphenol compounds, which also confirm their high antioxidant capacity, except for AuNPR2 obtained at pH 6.4. Among the AuNPRn, the smallest ones exhibited enhanced antimicrobial and anticancer activities.

Enhancement of T2* Weighted MRI Imaging Sensitivity of U87MG Glioblastoma Cells Using γ-Ray Irradiated Low Molecular Weight Hyaluronic Acid-Conjugated Iron Nanoparticles.

IntroductionIt has been reported that low-molecular-weight hyaluronic acid (LMWHA) exhibits a potentially beneficial effect on cancer therapy through targeting of CD44 receptors on tumor cell surfaces. However, its applicability towards tumor detection is still unclear. In this regard, LMWHA-conjugated iron (Fe3O4) nanoparticles (LMWHA-IONPs) were prepared in order to evaluate its application for enhancing the T2* weighted MRI imaging sensitivity for tumor detection.MethodsLMWHA and Fe3O4 NPs were produced using γ-ray irradiation and chemical co-precipitation methods, respectively. First, LMWHA-conjugated FITC was prepared to confirm the ability of LMWHA to target U87MG cells using fluorescence microscopy. The hydrodynamic size distribution and dispersion of the IONPs and prepared LMWHA-IONPs were analyzed using dynamic light scattering (DLS). In addition, cell viability assays were performed to examine the biocompatibility of LMWHA and LMWHA-IONPs toward U87MG human glioblastoma and NIH3T3 fibroblast cell lines. The ability of LMWHA-IONPs to target tumor cells was confirmed by detecting iron (Fe) ion content using the thiocyanate method. Finally, time-of-flight secondary ion mass spectrometry (TOF-SIMS) imaging and in vitro magnetic resonance imaging (MRI) were performed to confirm the contrast enhancement effect of LMWHA-IONPs.ResultsFlorescence analysis results showed that LMWHA-FITC successfully targeted the surfaces of both tested cell types. The ability of LMWHA to target U87MG cells was higher than for NIH3T3 cells. Cell viability experiments showed that the fabricated LMWHA-IONPs possessed good biocompatibility for both cell lines. After co-culturing test cells with the LMWHA-IONPs, detected Fe ion content in the U87MG cells was much higher than that of the NIH3T3 cells in both thiocyanate assays and TOF-SIMs images. Finally, the addition of LMWHA-IONPs to the U87MG cells resulted in an obvious improvement in T2* weighted MR image contrast compared to control NIH3T3 cells.DiscussionOverall, the present results suggest that LMWHA-IONPs fabricated in this study provide an effective MRI contrast agent for improving the diagnosis of early stage glioblastoma in MRI examinations.

Water uptake of subpollen aerosol particles: hygroscopic growth, cloud condensation nuclei activation, and liquid–liquid phase separation

Abstract. Pollen grains emitted from vegetation can release subpollen particles (SPPs) that contribute to the fine fraction of atmospheric aerosols and may act as cloud condensation nuclei (CCN), ice nuclei (IN), or aeroallergens. Here, we investigate and characterize the hygroscopic growth and CCN activation of birch, pine, and rapeseed SPPs. A high-humidity tandem differential mobility analyzer (HHTDMA) was used to measure particle restructuring and water uptake over a wide range of relative humidity (RH) from 2 % to 99.5 %, and a continuous flow CCN counter was used for size-resolved measurements of CCN activation at supersaturations (S) in the range of 0.2 % to 1.2 %. For both subsaturated and supersaturated conditions, effective hygroscopicity parameters, κ, were obtained by Köhler model calculations. Gravimetric and chemical analyses, electron microscopy, and dynamic light scattering measurements were performed to characterize further properties of SPPs from aqueous pollen extracts such as chemical composition (starch, proteins, DNA, and inorganic ions) and the hydrodynamic size distribution of water-insoluble material. All investigated SPP samples exhibited a sharp increase of water uptake and κ above ∼95 % RH, suggesting a liquid–liquid phase separation (LLPS). The HHTDMA measurements at RH &gt;95 % enable closure between the CCN activation at water vapor supersaturation and hygroscopic growth at subsaturated conditions, which is often not achieved when hygroscopicity tandem differential mobility analyzer (HTDMA) measurements are performed at lower RH where the water uptake and effective hygroscopicity may be limited by the effects of LLPS. Such effects may be important not only for closure between hygroscopic growth and CCN activation but also for the chemical reactivity, allergenic potential, and related health effects of SPPs.

Prevention of Edwardsiellosis in Clarias gariepinus using ginger and its nanoparticles with a reference to histopathological alterations

Edwardsiellosis is a serious septicemic bacterial disease that induces high mortality in fish of economic value such as Clarias gariepinus (C. gariepinus). Nanotechnology has become a modern indispensable tool for use in preventing and treating of fish diseases. Moreover, nanomaterials have the potential for prevention and treatment of fish diseases. The current study was aimed to evaluate the role of ginger (GN) and its nanoparticles (GNNPs) in Edwardsiellosis prevention in C. gariepinus after in-vitro determination of these natural products. Experimental infection, determination of the median lethal dose (LD50) of Edwardsiella tarda (E. tarda) and histopathological examinations were performed. GN and GNNPs synthesized by ball milling were characterized by Fourier transform infrared spectroscopy (FTIR), zeta potential, hydrodynamic particle size, scanning electron microscopy (SEM) and X-ray differentiation analysis (XRD). GNNPs had less negative surface charge and lower particle and hydrodynamic size distribution than bulk ginger. Also, the functional groups on the surface of GN particles were not affected by the milling process. GNNPs had higher antibacterial activity against E. tarda than GN. Experimentally infected C. gariepinus showed skin haemorrhagic ulcerations with a foul odor, loss of skin coloration and fins disintegration. The LD50 was 1.5 × 104 colony forming unit, CFU/ml. GNNPs succeeded in preventing Edwardsiellosis in dietary fed C. gariepinus with no mortality compared to 10% and 70% in group of C. gariepinus fed traditional GN and the positive control group, respectively. Dietary GNNPs induced a non-significant effect on liver functions with a slight increase in serum urea. These enzymes were significantly elevated in the positive control group. Regarding the histopathological findings, the positive control group showed severe histopathological lesions compared to the negative control group. Normal and mild histopathological alternations were observed in the groups fed GNNPs and GN then injected with E. tarda, respectively.

Twisted Intramolecular Charge Transfer—Aggregation-Induced Emission Fluorogen with Polymer Encapsulation-Enhanced Near-Infrared Emission for Bioimaging

Fluorescence probes with strong near-infrared (NIR) emission and water solubility are considered useful visualization tools for localization marking as well as investigating cell migration and tran...

Properties of single- and multi-core magnetic nanoparticles assessed by magnetic susceptibility measurements

Characterization of structural and magnetic properties of MNP ensembles is crucial in tailoring their performance for biomedical applications. In this work, we evaluate the size distribution of magnetic cores in single- and multi-core nanoparticles in water suspension using transmission electron microscopy (TEM) and static magnetization curve, with the geometrical core size ranges from 8.3 to 40.2 nm. A reasonable core size derived from the magnetization curve is obtained in comparison to the geometrical size from TEM image. The magnetic moment distribution possibly reveals that the reduction of effective magnetic core size is due to the magnetization degradation in cores. The hydrodynamic size and average anisotropy energy ratio obtained from the AC susceptibility response of MNPs from 5 Hz to 100 kHz are also evaluated. The complex distribution of relaxation time is constructed by applying a non-negative least square method to an AC susceptibility model that incorporates the inter- and intra-potential-well contributions. It is found that a log-normal distribution might not be adequate to represent the hydrodynamic size distribution reconstructed from the AC susceptibility responses of the suspended samples. It is demonstrated that the AC susceptibility model used in this study can be used to fairly estimate the average anisotropy energy ratio for MNP ensembles dominated by thermally blocked particles. Moreover, it can be suggested that besides the geometrical core size, the degree of core aggregation also plays an important role in determining the anisotropy energy ratio and effective magnetic moment.

Preparation and Characterization of Rutile Titania Nanofluids Stabilized in Different Surfactants Base Fluids

Background: Improvement of conventional heat transfer fluids for achieving higher energy efficiencies in thermal equipment is a key parameter to conserve energy in industries. The heat transfer fluids such as water, oil and ethylene glycol greatly suffer low heat transfer performance in industrial processes. There is a need to develop new types of heat transfer fluids that are more effective in terms of heat transfer performance. Nanofluids enhance thermal conductivity and improve the thermal performance of heat transfer systems. Methods: New titania nanofluid samples consisting of 0.0625 to 1% TiO2 nanoparticles were prepared and characterized. The method of preparation was based on prior precipitation of TiO2 from an ammoniacal solution of pH 9 and calcination at 900°C. Solubilization, homogenization and stabilization of the of the nanoparticles were performed by sonication in the presence of sodium dodecyl sulfate (SDS) anionic surfactant and cetyltrimethylammonium bromide (CTAB) cationic surfactant. Results: This treatment was also utilized to increase the stability and improve the thermal properties of the fluid. Conclusion: Several characterization techniques including measurements of hydrodynamic size distribution, zeta potential, transmission electron microscopy (TEM), viscosity, density, specific heat, thermal conductivity, and sedimentation photo capturing were used to measure and confirm the stability and sedimentation rate of the prepared nanofluids.

Characterization of Hen's Egg White To Use It as a Novel Platform To Culture Three-Dimensional Multicellular Tumor Spheroids.

We are standardizing protocols to develop egg white (EW) as a cost-effective platform for culture of three-dimensional (3-D) multicellular tumor spheroids for application in understanding tumor microenvironments and drug screening. In this article, we describe several physical and physiological characteristics of EW to use it as 3-D cell culture platform. Field emission scanning electron microscopy revealed the presence of different microstructures. Hydrodynamic size distribution data indicated nano- and micron-sized particles. Rheological measurements revealed the viscosity and viscoelastic behavior appropriate for maintaining cell viability and supporting 3-D cell growth under high-sheer conditions. It was found that thereis no autofluorescence, a requirement for imparting transparency and for microscopic observations of the spheroids. The EW facilitated the development of 3-D tumor spheroids, with an emphasis of difference in cell proliferation and intercellular cytoskeletal organization between two-dimensional and 3-D spheroid cultures. Put together, EW proves to be a cost-affordable and simple platform for 3-D culture of tumor spheroids.

Fatty acid coated iron oxide nanoparticle: Effect on stability, particle size and magnetic properties

Iron oxide nanoparticles (IONP) have been used as a magnetic base for polymeric composites. However, the magnetic properties of IONP are not fully exploited due to the difficulties to obtain a good dispersion and high stablity within the polymeric matrix. The objective of this study is to improve the stability, dispersive ability and separability of IONP by fatty acid coating. Fatty acid coated iron oxide nanoparticle (C-IONP) has been selected due to its hydrophobicity and hydrophilicity characteristics and consequently useful to be incorporated with nitrile butadiene rubber (NBR) as a polymeric compound model. The facile precipitation method has been used to synthesize C-IONP with good polydispersity of iron oxide nanoparticle (IONP) and high compatibility with polar and non polar medium was addressed. Iron (II) sulphate heptahydrate and ammonium hydroxide were selected as precursors to synthesize IONP at 60 °C at 1.5 h aging time and subsequently coated with series of fatty acids (oleic, capric, myristic, palmitic and stearic acids). It is observed that, oleic acid C-IONP has excellent compatibility in water and NBR latex medium, with small hydrodynamic size and narrow particle size distribution. This is due the existence of double bond in oleic acid backbone chain. The magnetization saturation of oleic acid C-IONP was 54.53 emu/g hence it can be incorporated to NBR latex. This therefore demonstrated that, highly magnetic polymeric composite could be produced with good and homogeneously dispersed and stable IONP.

Facile and green synthesis of cobalt oxide nanoparticles using ethanolic extract of Trigonella foenumgraceum (Fenugreek) leaves

Cobalt oxide nanoparticles (Co3O4 NPs) were successfully synthesized using ethanolic extract of Trigonella foenumgraceum L. (fenugreek) leaves as a green, potentially low cost, and easily biosynthesized method. The organic bioactive compounds present in fenugreek leaves extract acted as both reducing agents and stabilizing agents for synthesizing metal NPs from cobalt chloride hexahydrate as a precursor. As evidence from UV/Visible spectroscopy, energy dispersive spectroscopy (EDS), and X-ray diffraction analysis (XRD) studies, high alkaline pH was found favorable for the preparation of pure and crystallized single-phase Co3O4 NPs. The interaction of biomolecules from fenugreek leaves extract with Co3O4 NPs was defined by Fourier transform infrared spectroscopy (FTIR) analysis and X-ray photoelectron spectroscopy (XPS). The hydrodynamic size and surface charge of the biosynthesized NPs were measured using light-scattering (DLS) and zeta potential analyses; revealed the formation of negative charged Co3O4 NPs with uniform hydrodynamic size distribution. According to transmission electron microscopy (TEM) analysis, quasi-spherical Co3O4 NPs were synthesized with an average size of 13.2 nm under the modified condition of pH 12 and reaction time of 2 h through inexpensive, environmental friendly benign synthesis process without the use of any additional toxic chemical.

Microwave-assisted green synthesis of silver nanoparticles using dried extracts of Chlorella vulgaris and antibacterial activity studies

AbstractGreen synthesis of metallic nanoparticles (NPs) is acquiring considerable attention due to its environmental and economic superiorities over other methods. This study describes the practical synthesis of silver nanoparticles (AgNPs) through the reduction of silver nitrate solution using an algal source, Chlorella vulgaris, as the reducing as well as the stabilizing agent. The energy required for this synthesis was supplied by microwave radiation. The ultraviolet-visible spectroscopy exhibited a single peak related to the surface plasmon absorbance of AgNPs at 431 nm. The AgNPs with high stability (a zeta potential of −17 mV), hydrodynamic size distribution of 1–50 nm, and mostly spherical shape were obtained through a 10 min process. Fourier transform infrared spectroscopy analysis revealed that several functional groups, including carbonyl groups of C. vulgaris, play a significant role in the formation of functional NPs. Antibacterial features of the produced AgNPs were verified against those of Salmonella enterica subsp. enterica serovar typhimurium and Staphylococcus aureus, demonstrating a considerable growth inhibition at increasing concentrations of the NPs. As a result, the formed AgNPs can be used as a promising agent against bacterial diseases.