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Bastnaesite is an important rare earth mineral and is usually beneficiated by flotation. Sodium silicate is commonly used to depress calcium-bearing gangue minerals, however it can also depress bastnaesite when Ca2+ ions exist in the pulp. In this study, the effect of Ca2+ ions and sodium silicate individually or in combination on bastnaesite flotation was studied through micro-flotation, zeta potential, fluorescence spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. Micro-flotation results show that the combination of Ca2+ ions and sodium silicate depresses bastnaesite more severely due to their synergistic effect. Zeta potential results show that the combination renders the surface potential of bastnaesite negatively shifted more significantly. Fluorescence spectroscopy shows that the combination decreases the surface hydrophobicity of bastnaesite more severely. XPS shows that the combination increases the adsorption of sodium silicate on bastnaesite by forming hydrophilic Ca-SiO3 precipitate, which causes more serious depression on bastnaesite flotation.

Monazite ((Ce, La)PO4) is one of the major types of light rare earth minerals from which the light rare earth elements cerium (Ce) and lanthanum (La) are economically extracted. Flotation is extensively used to recover fine-grained monazite. Sodium oleate (NaOL) is considered as the collector with the strong collecting ability for monazite flotation. However, this study shows that its collecting ability is still limited. In this paper, a phosphonic acid, nonane-1,1-bisphosphonic acid (C9-BPA), was employed as the novel collector in place of NaOL. Flotation experiments show that even when the C9-BPA dosage is less than one-fifth of the NaOL dosage, the monazite recovery using C9-BPA as the collector is approximately 22 wt% higher than that using NaOL. The mechanism by which C9-BPA adsorbs on monazite was investigated using zeta potential, infrared (IR) spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements as well as first-principles calculations. Zeta potential measurements show a more significant decrease in the zeta potentials of monazite after the addition of C9-BPA compared to those after the addition of NaOL. For C9-BPA-treated monazite, the characteristic peaks of C9-BPA were observed in the IR and C 1s XPS spectrum, whereas for monazite treated by NaOL, no characteristic peak of NaOL was observed. Experimental results show that C9-BPA has a stronger affinity towards the monazite surface than NaOL as confirmed by the higher adsorption energy of CP-BPA on the monazite surface (‒204.22 kJ/mol) than NaOL (‒48.48 kJ/mol). This study demonstrates an extensive application value and prospect of C9-BPA in monazite flotation and helps design novel collectors with strong collecting ability for monazite flotation.

In the present work gold nanoparticles were synthesized by green method using Aegle marmelos bark extract and the reaction conditions were optimized. Synthesized nanoparticles were characterized by using different analytical techniques including UV–Visible spectroscopy, FTIR (Fourier Transform Infra Red) spectroscopy, TEM (Transmission electron microscopy), DLS (Dynamic Light Scattering) and Zeta Potential Analyser. The Biosynthesized gold nanoparticles were then used for colorimetric detection of Cr(III) and Al(III) from aqueous medium. It was found that the detection limit with nanoparticles was as low as 0.5 mM for Cr(III) ion and 0.01 mM for Al(III) ions in aqueous medium.

CAPE found in propolis has become the subject of research interest as it has various medicinal benefits such as antiviral, anti-inflammatory, antioxidant, anticancer and immunomodulatory properties [1] . In this study, propolis obtained in Kuantan, Pahang is encapsulated using biodegradable polymer, vitamin E TPGS as a drug delivery system whereas TPGS-CAPE is used as a control. The findings show the physical characterization of propolis loaded vitamin E TPGS polymeric micelles which includes size, polydispersity index, zeta potential, shape and morphology and encapsulation efficiency.

Molecularly imprinted polymers (MIPs) having the potential to mimic the selectivity and sensitivity of biological molecular recognition are blended here with piezoelectric transducer (EQCM) able to provide ‘real time’ monitoring of molecular level events with extreme sensitivity. In this work, molecularly imprinted polymer nanoparticles selective for a psychoactive drug, cathinone were synthesized, characterized and applied for specific and selective uptake in water. Nanoparticles were separated by centrifugation and characterized for their size and zeta potential. p-Phenylene diamine was chosen as functional monomer to imprint S-cathinone via in silico studies. Molecularly imprinted nanoparticles were eletrodeposited on gold coated quartz crystal electrode of electrochemical quartz crystal microbalance (EQCM). Molecular imprinting experiments were optimized for selective and specific uptake of S-cathinone. Thus fabricated EQCM sensor was able to discriminate between stereoisomers and other close structural analogues also. Imprinting data were successfully fitted to Freundlich adsorption isotherm and curves for non-imprinted and imprinted data were compared. Under optimized conditions, response of nanoMIP-EQCM sensor is linearly proportional to S-cathinone concentration with detection limit as 0.12 ng mL−1 and quantification limit as 0.409 ng mL−1 and imprinting factor as 8. Hence, a highly specific and selective nanoMIP-EQCM sensor is fabricated in a facile manner.

Liquid crystalline nanoparticles (Cubosomes) are unique structures for the effective delivery of many pharmaceutical drugs. The present study is aimed to develop and characterize novel cubosomal formulation containing dexamethasone (DMS). The cubosomes were incorporated into hydrogel for prolonged delivery of DMS to treat vitiligo. The cubosomes were prepared via top-down technique using different concentrations of glyceryl monooleate (GMO) (lipid phase), poloxamer 407 (P 407) (non-ionic surfactant), oleic acid (fatty acid) and water (aqueous phase). The formulated cubosomal formulations were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), zeta size analyzer for their surface morphology, particle size and zeta potential. Further, they were evaluated for % entrapment efficiency and in-vitro drug release. The optimized F-12 formulation exhibited a particle size of 250.40 nm and a zeta potential of −36.10 ± 2.56 mV. The in-vitro drug release of 88.12% was achieved at 12th h. The F-12 formulation was incorporated into 1% carbopol 940 to form cubogel (CG). The F-12 loaded CG was evaluated for physical characteristics, pH, drug content, viscosity, spreadability, and in-vitro drug release studies. All the evaluation parameters for the CG formulation were said to be within the standard limits. The in-vitro drug release for DMS loaded CG was found to be 83.58% at end of 12 h, thus indicating its potential as a better sustained drug delivery system for vitiligo.

Silver nanoparticle (AgNP) synthesis using microalgae is a promising low-cost sustainable alternative. High CO2 tolerant microalgae have not yet been explored for this application. This study pretends to determine the potential of an environmental green algae Desmodesmus abundans acclimated to low and high CO2 (LCA and HCA strains, respectively) as a platform for AgNPs synthesis and evaluate the effect of pH (5, 7.5, 11) and biological component (cells, supernatant and both components) in comparison to a collection strain Spirulina platensis. Exponential grown cultures were centrifuged, the pellet resuspended in 10 mM AgNO3 prepared in water or supernatant at different pH and incubated for 40 h (24 °C, continuous light). After, the filtrated solution was characterized using UV–visible absorption spectra, Zetasizer and scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy. Results showed drastic differences between strains. No nanoparticles were observed with strain LCA, except at pH 11 using the pellet, which generated large particles (127.8 ± 14.8 nm diameter, −26.7 ± 2.4 mV zeta potential). In contrast, the HCA strain in these conditions showed the smallest AgNPs with the lowest zeta potential (14.9 ± 6.4 nm, −32.7 ± 5.3 mV). When the supernatant was conserved, HCA exhibited AgNPs in all pH solutions, with smallest sizes at pH 11 (27.7 ± 14.0 nm, −20.0 ± 1.8 mV). In addition, the HCA supernatant alone showed reducing potential for AgNP synthesis (51.8 ± 20.7 nm, −17.4 ± 1.3 mV). S. platensis also generated AgNPs in all conditions, but nanoscale particles were observed only at pH 11 (18.3 ± 7.5 nm, −33.9 ± 2.4 mV). In conclusion, high CO2 atmospheres seem to potentiate AgNPs synthesis by microalgae with interesting properties accordingly to biological component employed, representing a potential byproduct in CO2 mitigation systems.

openaire: EC/H2020/730480/EU//ITERAMS This work was supported by the European Union H2020 program under Grant Agreement number Horizon 2020 Framework Programme 730480. This study investigated the impact of tetrathionate ions on selected sulfide mineral surfaces and their flotation response to tetrathionates using X-ray photoelectron spectroscopy (XPS), zeta potential and batch flotation studies and linking the results to previously reported electrochemistry, FTIR and microflotation studies. XPS revealed that tetrathionates have the propensity to oxidize minerals, changing the chemical composition of the mineral surface. This surface alteration renders the sulfide minerals hydrophilic through sulphoxy and hydroxy entities reducing collector adsorption as noted in FTIR and mixed potential studies. Zeta potentials showed little specific adsorption of tetrathionates on the sulfides except at moderately high concentrations, i.e., 1000 mg/L. Batch flotation showed that tetrathionates in solution depressed sulfide minerals, particularly galena, reducing its recovery to the concentrates in support of earlier microflotation results.

Nanostructures of layered materials have gained increasing attention in photocatalytic and water-treatment processes. Herein, we report on sub-30 nm SnS2 nanosheets (NSs) which can perform photocatalytic reduction of Cr(VI) to Cr(III) quite efficiently on one hand, while removes large quantities of toxic organic dye molecules by choosing an adsorption mode of operation over photo-degradation on the other hand, unlike most other SnS2 nanostructures. The NSs have a highly extended crystallinity growing perpendicular to the (0 0 1) lattice direction but exhibit poor X-ray diffraction for the 10 l (1 = 1,2,3…) lattice planes. With such defects, the NSs have a narrow bandgap of 2.21 eV and exhibit a significant photocurrent density at near band-edge illumination. Cr(VI) photo-reduction using the SnS2 NSs follows a first-order reaction kinetics (rate constant of 0.10 min-1), five-fold higher than commercial TiO2 (P-25). Furthermore, the NSs adsorb Rhodamine B dye molecules from an aqueous solution by forming a monolayer of dye molecules following a pseudo-second-order kinetic model and exhibit an adsorption capacity of ∼ 53.28 mg/g. We show that the NSs have a Zeta potential of ∼ –22 eV and preferably adsorb cationic dyes only. Thus the SnS2 NSs can be effective for Cr(VI) contaminated waste-water treatment in a photocatalytic manner and can also act as a potential adsorbent for polluting dye molecules either in the presence or absence of sunlight. While both these activities are known for SnS2 as well as other materials, the competitive nature of the two mechanisms while each of them is a possibility has never been investigated. Therefore, besides the high activities, the study highlights the presence of different active sites on the material surface that can respond preferentially to either inorganic or organic impurities.

Carbon dots (CDs) are novel fluorescent nanomaterials with good water solubility, high resistance to photobleaching and low toxicity. While, there are few studies elaborate on the relationship among reaction conditions, properties and applications of CDs. In this study, a series of CDs are synthesized through a one-pot hydrothermal method, and different reaction conditions are carried out to study the influencing factors of CDs properties. As a result, with the increase of temperature and reaction time, the particle size and zeta potential of CDs increased, the maximum emission wavelength red-shifted and the fluorescence quantum yield (QY) improved. Among them, CD3006 has good water solubility and highest QY of 81.4%, which is beneficial for its applications in bioimaging and ion detection. CD3006 is almost nontoxic in cells at a concentration of 500 μg/mL. In addition, the positive charged CD3006 shows nuclear targeting potential because of its combination with DNA through electrostatic interaction in nucleus. The properties of CDs can be greatly enhanced by controlling reaction conditions, and it provides great application prospects.

Flotation separation and recovery of rare earth minerals (REM) have returned to an important position due to the growing strategy demand for rare earth elements (REE). In this paper, a comparative investigation into the floatability of bastnaesite ((Ce,La)FCO3) was conducted by using three di/trialkyl phosphate collectors, di(2-ethylhexyl) phosphate (DEHPA), dibutyl phosphate (DBP) and tributyl phosphate (TBP). The density functional theory (DFT) computation recommends that the chemical activity of the three phosphate collectors is in order of DEHPA ≥ DBP >> TBP, and their hydrophobization as-suggested by the lgP (oil-water partition coefficient) value is in the order of DEHPA > TBP > DBP. The micro-flotation indicates that the preferable pH values for flotation of bastnaesite with the three phosphate collectors are 7.0–8.0, and DEHPA achieves much higher flotation recovery of bastnaesite, followed by DBP, and then TBP, which coincides with their reactivity and hydrophobicity, the two prerequisites for froth flotation. The contact angle, zeta potential, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) deduce that DEHPA likely reacts with the Ce(Ⅲ) atoms of bastnaesite interface through its O atom(s) of the P(=O)–O– group to generate the Ce–O–P bonds, and its two 2-ethylhexyl groups orient outside for attaching bubbles, resulting in flotation enrichment of bastnaesite. Furthermore, this investigation offers a novel strategy for developing collectors in selective beneficiation of REM.

In order to eliminate multiple coexisting pollutants in environmental wastewater, a magnetic three-dimensional hierarchical porous flower-like N, Co-doped graphitic carbon nano-polyhedra decorated NiCo-layered double oxides (N-Co@C/NiCo-LDOs) adsorption material was synthesized, which consisted of two-dimensional LDOs nanosheets with functionalized surfaces (N, Co-doped graphitic carbon loaded on both sides of NiCo-LDOs nanosheets). The adsorption properties of N-Co@C/NiCo-LDOs for five types of typical pollutants (cationic dyes: rhodamine b, methylene blue; pesticides: ethofenprox, bifenthrin; anionic dyes: methyl orange, congo red; inorganic cations: Cr2+, Cd2+, Pb2+, Zn2+, inorganic anions: Cr2O72−, AsO33−) were investigated systematically in single and coexisting systems. Combined with the results of FTIR and zeta potential, the adsorption mechanism was discussed. By virtue of its hierarchical porous architecture and the combined effect of functionalized surfaces and LODs supporter, the as-prepared N-Co@C/NiCo-LDOs demonstrates excellent adsorption performance towards five types of typical pollutants with fast adsorption rate, high adsorption capacity and good co-adsorption performance. More importantly, the N-Co@C/NiCo-LDOs showed satisfactory removal efficiency, stability and reusability in model wastewater. The broad-spectrum, rapid, easily separable, and reusable adsorption properties make N-Co@C/NiCo-LDOs promising for highly efficient wastewater treatments. This work also provides a feasible way for the preparation of adsorption materials for the treatment of complex wastewater systems.

This research aimed to prepare 166Dy2O3-iPSMA/166Ho2O3-iPSMA nanoparticles (166Dy2O3/166Ho2O3-iPSMA NPs) and assess the radiation absorbed dose produced by the nanosystem to hepatic cancer cells by using experimental in vitro and in vivo biokinetic data. Dy2O3NPs were synthesized and functionalized with the prostate-specific membrane antigen inhibitor peptide (iPSMA). Fourier transform infrared (FTIR) spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DSL) and zeta potential analyses indicated the formation of Dy2O3-iPSMA NPs (46.11 ± 13.24 nm). After neutron activation, a stable 166Dy2O3/166Ho2O3- iPSMA nanosystem was obtained, which showed adequate affinity to the PSMA receptor in HepG2 cancer cells (Kd = 9.87 ± 2.27 nM). in vitro studies indicated high 166Dy2O3/166Ho2O3-iPSMA internalization in cancer cells, with high radiation doses to cell nuclei (107 Gy) and cytotoxic effects, resulting in a significant reduction in HepG2 cell viability (decreasing to 2.12 ± 0.31%). After intratumoral administration in mice, the nanosystem biokinetic profile indicated significant retention into the tumoral mass, producing ablative radiation doses (>70 Gy).

With using Sn2+ as tin source, l -cysteine as sulphur source and polyvinyl pyrrolidone (PVP, Mw = 1300000) as surfactant, a novel three-dimensional and crescent-like SnS nanocrystal (NCs) was successfully synthesized in a one-pot hydrothermal method. The as-prepared SnS NCs displayed uniform crescent-like morphological structure, and demonstrated excellent efficiency for the adsorption of cationic dyes such as rhodamine B (RhB) and methylene blue (MB). Kinetic analysis indicated that the adsorption process followed the pseudo second-order model, and the maximum capacity of the SnS NCs to adsorb MB was determined by Langmuir equation to be 252 mg⋅g−1 at 298 K. The pH dependence of SnS NCs on the adsorption of cationic dyes and the characterization of zeta potential jointly suggested the existence of electrostatic attraction in the process. Overall, this study showed that electrostatic field of functional groups and the capping of PVP could significantly enhance the adsorption performance of the SnS NCs, and also provides a novel insight into the development of highly efficient inorganic adsorbents for cationic dyes.

The TOPSi/HAP composite was obtained after heat treatment of thermally oxidized porous silicon (TOPSi) spin-coated with Hydroxyapatite (HAP) precursor solution. Silicon–Calcium Phosphate composite nanoparticles (SiCaPs) were synthesized in distilled water by laser ablation method using the TOPSi/HAP composite as the target material. According to Scanning Electron Microscopy (SEM), Fourier Transformed Infrared spectroscopy (FTIR), Energy-dispersive X-ray Spectroscopy (EDS), Dynamic Light Scattering (DLS) and Zeta Potential analyzes, SiCAPs are ultra-pure, spherical shaped nanoparticles with an average hydrodynamic diameter of 120 nm and a Zeta Potential of −20 mV for Ph 4,5. The proposed unique method enabled the SiCaPs synthesis. By changing some parameters of the synthesis conditions, SiCaPs of various properties can be designed for bone tissue engineering, wound healing, drug delivery, medical adhesives, and various biomedical applications.

The present research focuses on the development of porous MgAl-layered double hydroxide microspheres with high sphericity and uniform particle size distribution. This is based on the droplet coagulation technique using alginate biopolymer as a binder. To achieve this, the suspension formulation was systematically optimized based on zeta potential and rheology measurements. The structural, microtextural and porosity characteristics of the MgAl-LDH powder and the corresponding obtained microspheres were investigated by X-ray diffraction, diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, optical and scanning electron microscopy, N-2 sorption and Hg intrusion characterization techniques. The combination of these techniques allowed us to highlight that this shaping process leads to the production of porous microspheres in which the LDH plate-like particles are held together in a calcium alginate network without altering their structural features. This research opens up new opportunities for the LDH-type materials towards packed bed applications, such as chemical reactors or sorption columns. (C) 2021 Published by Elsevier B.V.

Carbon dot (CDs) were prepared for carrying DOX (Doxorubicin) or FAC (Ferric ammonium citrate), and the loading mechanism and release kinetics of CDs-drugs were studied. CDs were prepared using peony pollen and urea, and characterized by TEM, XRD, 13C NMR, XPS, UV, FT-IR, DLS and zeta potential. The obtained CDs were rich of –NH2 group on the surface, amorphous phase, spherical morphology with the diameter about 5 nm, and had a blue fluorescence with the quantum yield (QY) of 12%. Iron disorders can cause cancer or anemia. DOX is used for treating cancer, but has severe side effects. FAC is an iron supplement agent, but had low bioavailability. CDs carried DOX (or FAC) through –N=C– (or –CONH–) bond, had high loading efficiency for DOX (37.2%) and FAC (54.0%) by optimizing mass ratios of mCDs to mdrug and reacted overnight. Cellular experiments showed that CDs-drugs had lower cytotoxicity than free drugs and CDs co-located with the drug. In vitro release indicated that CDs-DOX had pH-targeted property and CDs-FAC could be absorbed easily. CDs-drug release belonged to Weibull model, and release mechanism was determined by the bonding way between CDs and drug. CDs had potential applications in delivery drugs with –C=O or –COOH group.

SiC is a promising functional ceramic material with many great properties. High concentrated SiC slurry with excellent rheology and stability is required in some processes of ceramic forming. In this work, the dispersion of SiC powders was obviously improved by ternary modifiers: γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560), sodium humate and sodium dodecyl sulfate (SDS). Modified SiC slurry showed the lowest viscosity of 0.168 Pa s at a solid content of 50 vol%. The maximum absolute value of zeta potential of SiC increased from 47.3 to 61.6 mV by modification. Sedimentation experiments showed that a highly stable suspension of modified SiC was obtained at pH 10. SiC green body with high density of 2.643 g/cm3 was prepared with modified powders by slip casting. X-ray photoelectron spectra (XPS) and thermogravimetry (TG) measurements indicated the adsorption of modifiers on SiC surface. Therefore, modified SiC powders could stably disperse in aqueous media due to the increase of electrosteric repulsion between particles. The novel strategy used in this study could further improve the dispersion of SiC powders.

Aim: The aim of the study was to formulate, characterize, and evaluate the Resveratrol- loaded Cubosomes (RC) for topical application. Background: Resveratrol (RV) is a nutraceutical compound with exciting pharmacological potential in different diseases, including cancers. Many studies on resveratrol have been reported for anti- melanoma activity. Due to its low bioavailability, the therapeutic activities of resveratrol are strongly limited. Hence, an approach with nanotechnology has been made to increase its activity through transdermal drug delivery. Objective: To formulate, characterize, and evaluate the resveratrol-loaded cubosomes (RC). To evaluate Resveratrol-loaded Cubosomal Gel (RC-Gel) for its topical application. Methods: RC was formulated by homogenization technique and optimized using a 2-factor 3-level factorial design. Formulated RCs were characterized for particle size, zeta potential, and entrapment efficiency. Optimized RC was evaluated for in vitro release and stability study. Optimized RC was further formulated into cubosomal gel (RC-Gel) using carbopol and evaluated for drug permeation and deposition. Furthermore, developed RC-Gel was evaluated for its topical application using skin irritancy, toxicity, and in vivo local bioavailability studies. Methods: RC was formulated by homogenization technique and optimized using a 2-factor 3-level factorial design. Formulated RCs were characterized for particle size, zeta potential, and entrapment efficiency. Optimized RC was evaluated for in vitro release and stability study. Optimized RC was further formulated into cubosomal gel (RC-Gel) using carbopol and evaluated for drug permeation and deposition. Furthermore, developed RC-Gel was evaluated for its topical application using skin irritancy, toxicity, and in vivo local bioavailability studies. Results: The optimized RC indicated cubic-shaped structure with mean particle size, entrapment efficiency, and zeta potential were 113±2.36 nm, 85.07 ± 0.91%, and -27.40 ± 1.40 mV, respectively. In vitro drug release of optimized RC demonstrated biphasic drug release with the diffusion-controlled release of resveratrol (RV) (87.20 ± 3.91%). The RC-Gel demonstrated better drug permeation and deposition in mice skin layers. The composition of RC-Gel has been proved non-irritant to mice skin. In vivo local bioavailability study depicted the good potential of RC-Gel for skin localization. Conclusion: The RC nanoformulation proposes a promising drug delivery system for melanoma treatment simply through topical application.

This work aimed to prepare nanocellulose-based Pickering emulsions using cinnamon essential oil. Different formulations were investigated by varying the preparation time, homogenization speed, oil and nanocellulose concentration, and morphology. The emulsions were first characterized by droplet size, morphologies, and storage stability. The Design of Experiments (DoE) was used to evaluate the parameter’s effects on the emulsions’ stability, and the emulsions with optimum particle size and stability were evaluated by antimicrobial activity. The more stable emulsions required higher energy in the system to obtain efficient emulsification. The cellulose nanocrystal (CNC) emulsions showed a 30% oil volume as a constant to obtain a low creaming index (34.4% and 42.8%) and zeta potential values around −29 mV, indicating an electrostatic stabilization. The cellulose nanofiber (CNF) emulsions showed 100% stability after a month using a 20% oil volume as a constant and Zeta potential values around −15 mV, indicating a steric stabilization. CNF-emulsions’ inhibition halos for Bacilus subtilis were 30.1 ± 3.7% smaller than those found in CNC-emulsions (65 ± 2.9 mm), while Pseudomonasaeruginosas almost do not present differences in the inhibition halos. These results suggest that the nanocellulose morphology may promote a regulation on the EO migration to the medium, as well that this migration ratio does not affect the bacteria.

This study used reactive ultra-fine fly ash (RUFA) as the primary raw materials in the preparation of a novel RUFA geopolymer. Note that the solution to binder weight ratio was maintained at the same level by varying the concentration of the NaOH solution. Extensive analysis was conducted to characterize the flowability and mechanical properties. X-ray diffraction (XRD), Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS), Fourier transform infrared spectroscopy (FT-IR), mercury intrusion porosimetry (MIP), thermogravimetric (TG), and zeta potential analyses were used to examine the microstructure of RUFA geopolymers. Increasing the concentration of NaOH also led to an increase in compressive strength. A high NaOH concentration of 12 mol/L resulted in compressive strength of 97.6 MPa at 28 days. Finally, increasing the concentration of NaOH increased the formation of the primary reaction geopolymerization product, N-A-S-H gel, resulting in a denser microstructure with lower porosity.

Low molecular weight branched polyethylenimines (LMW bPEIs) are almost nontoxic but display poor transfection efficiency due to lack of adequate complexation ability with nucleic acids followed by transportation across the cell membrane. Here, a series of amphiphilic retinoyl-bPEI conjugates (RP-1, RP-2 and RP-3) has been synthesized by allowing the reaction between bPEI (1.8 kDa) and a bioactive and hydrophobic vitamin A metabolite, all-trans-retinoic acid (ATRA), in varying amounts. In aqueous medium, these conjugates self-assembled into core-shell RP nanocomposites with size ranging from ~113–178 nm and zeta potential from ~ +15–35 mV. Evaluation of pDNA complexes of RP nanocomposites revealed that all the complexes exhibited significantly enhanced transfection efficiency without compromising on the cytocompatibility. RP-3/pDNA complex, with the highest content of retinoic acid, exhibited the best transfection efficiency. Further, due to anticancer properties of ATRA, these nanocomposites significantly reduced the viability of cancer cells (HepG2 and MCF-7 cells) without affecting the viability of non-cancerous cells (HEK 293 cells) demonstrating the cell-selective nature of the formulated nanocomposites. The intracellular trafficking and co-localization studies involving RP-3 nanocomposites also showed their higher uptake with intracellular and nuclear accumulation properties. Altogether, the results demonstrate the promising potential of the RP conjugates that can be used in future hepatocellular carcinoma targeted gene delivery applications.

High hydrostatic pressure-treated corn starch (HPCS) and waxy corn starch (HPWCS) at three concentrations (10%, 15%, and 20%) were applied as novel fat replacers in a model low O/W emulsion at three fat reduction levels (FR, 25%, 50%, and 75%) and some physical, textural and rheological characteristics and stability of the samples were examined and compared with the control. Applying higher concentrations of HPCS and HPWCS increased the zeta potential, hardness and consistency (mainly for HPWCS samples), reversely decreased the Z-average particle size and polydispersity index of the reduced-fat emulsions, but augmenting FR levels caused a reverse inclination. The rheological assay cleared that the emulsions prepared with HPWCS had greater elastic modulus (G') and more gap between G' and viscous modulus (G″) at all concentrations than the HPCS-contained samples. The critical stress (τc) of 25FR samples were significantly higher than the control, showing the well stability of reduced-fat samples. Also, the τc of the HPCS-contained emulsions reduced meaningfully when the FR level increased from 25% to 75%, but for the HPWCS samples, fat reduction didn't change the τc value significantly up to 50% fat reduction. Based on Tangδs(n-LVE), HPWCS contained samples showed more spreadability than the HPCS-contained emulsions.

Mandarin (Citrus reticulata L.) essential oil (MEO) reportedly displays excellent antimicrobial properties. In this study, MEO was loaded into chitosan nanoparticles (CSNPs). The characteristics, antibacterial properties and benefit in pork preservation of MEO-CSNPs were evaluated. The MEO-CSNPs displayed an excellent encapsulation efficiency (EE) (67.32%–82.35%), the particle size values of 131.3 nm–161.9 nm, and the absolute zeta potential values above 30 mV. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, and thermogravimetric analysis (TGA) revealed that the MEO was incorporated into CSNPs without requiring a chemical reaction, the antibacterial activity of the MEO remained. Furthermore, the damage of MEO-chitosan nanoemulsions (MEO-CSs) to the cell membranes of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) was confirmed by the change of bacterial cell morphology. The anti-biofilm assays verified that the MEO-CSs substantially inhibited biofilm formation and destroyed the mature biofilms. MEO-CSs were also applied to pork, proving a great potential for pork preservation. This study provides a potential approach for developing and utilizing MEO-CSs as natural antimicrobial agents in the food industry.

In the present study, we aimed to formulate, optimize, and characterize azithromycin chitosan coated niosomes (AZM-CTS-NSM) as a novel colloidal system that increases precorneal residence period, eye permeation, and bioavailability. AZM-NSM was formulated via a modified thin-film hydration strategy and then coated with CTS. We assessed the influence of the cholesterol: surfactant molar ratio, CTS concentration, and surfactant type on particle diameter, entrapment, zeta potential, and NSM adhesion force to the corneal mucosal membrane and employed a central composite design (CCD). The resulting optimized AZM-CTS-NSM has a mean diameter of 376 nm, entrapment of 74.2%, surface charge of 32.1 mV, and mucoadhesion force of 3114 dyne/cm2. The optimized AZM-CTS-NSM demonstrated a prolonged in vitro release behavior. When compared with commercial eye drops, the optimized AZM-CTS-NSM produced a 2.61-fold increase in the apparent permeability coefficient, significantly improving corneal permeability. Additionally, ocular irritation was assessed, with no major irritant effects found to be induced by the formulated NSM. Compared with AZM commercial drops, the optimized AZM-CTS-NSM revealed ˃ 3-fold increase in AZM concentration in the rabbit eyes. Collectively, these findings indicate that CTS-NSM is a potentially valuable ocular nanocarrier that could augment the efficacy of AZM.

In the current investigation, an instantaneous, single step, cost-effective, and environmentally safe biosynthesis of gold nanoparticles (AuNPs) using the aqueous extract of P. salicifolia leaves is reported for the first time. P. salicifolia-AuNPs were characterized via several techniques including UV–Visible spectroscopy, Zeta potential, Fourier Transform Infrared (FT-IR) spectroscopy, Energy Dispersive X-ray spectroscopy (EDX) attached to SEM, High-resolution Transmission electron microscope (HRTEM), X-ray diffraction (XRD), and Selected Area Electron Diffraction (SAED), EDX elemental mapping and X-ray Photoelectron Spectroscopy (XPS). Results demonstrated the formation of violet-colored, mostly spherical-shaped AuNPs with a diameter between 5 and 23 nm and a plasmon peak at 535 nm indicated the successful phytosynthesis of AuNPs using the aqueous extract of the investigated species. The cytotoxicity investigation of the phytosynthesized AuNPs using Sulphorhodamine-B (SRB) assay reflected superb cell capability in inhibiting the growth and proliferation of human breast cancer cells (MCF7 cell line) with IC50 2.24 μg/mL. Additionally, P. salicifolia-AuNPs were proved to be a potent antioxidant. These results offer a promising route of AuNPs synthesis using the extract of P. salicifolia.

Copper ferrite (CuFe2O4) is one of the most popular ferrite spinel semiconductors due to its superparamagnetic properties. In this study, CuFe2O4 nanoparticles were successfully prepared through green synthesis mediated by Morus alba L. leaf extract. Secondary metabolites, such as alkaloids and saponins, in Morus alba L. leaf extract acted as a weak base provider and as a capping agent in the formation of CuFe2O4. The crystal structure, grain morphology, particle size, and magnetic properties of the nanoparticles were investigated. X-ray diffraction (XRD) data confirms the formation of the CuFe2O4 phase with a cubic Fd-3ms space group. The nanoparticles mediated by Morus alba L. have a spherical shape with distributed particle sizes at 20–70 nm. In the evaluation of stability, the nanoparticles agglomerate with a zeta potential value of −21.7 mV and have a soft ferromagnetic nature with Hc, Mr, and Ms values of 175.44 Oe, 1.75 emu/g, and 14.16 emu/g, respectively. The catalytic ability of CuFe2O4 nanoparticles in the Mannich reaction showed good catalyst performance with a yield of 83.83% at optimum conditions. Green synthesis using Morus alba L. leaf extract offers a more environmentally friendly and effective method for obtaining CuFe2O4 nanoparticles with good characteristics.

Hemorrhage is a leading cause of preventable death in both military combat and civilian accidents. To overcome these challenges, an affordable and effective bandage is must required substance. A novel strategy is reported for developing chitosan-casein (CC) based self-assembled nanofibrous polyelectrolyte complex (PEC) for rapid blood clotting. The amide group (1630 cm−1) and phosphate group (910 cm−1) of chitosan-casein can form PEC at pH 8.2 ± 0.2. The PECs contain intertwined nanofibers (≤100 nm diameter) with a high surface area. Increasing chitosan percentage from 30% (CC30) to 50% (CC50) or 70% (CC70) results, increase in zeta potential of PEC from -9.14 ± 3.3 to 7.46 ± 3.7 and 14.8 ± 3.3 mV, respectively. Under in vitro conditions, the CC30, CC50, and CC70 PECs allow platelet adhesion and rapidly absorbs blood fluid to form mechanically stable blood clots within 9 ± 3, 16 ± 3, and 30 ± 4 s, respectively, which are better than Celox™ (90 ± 3 s). In vivo application of PEC (CC50) causes clotting within 37 ± 6 s of large (1 cm) arterial incision in rabbit models. The PEC is biocompatible with promising hemostatic efficiency. This is the first report of nanofibrous PEC from chitosan and casein for rapid clotting, to the best of our knowledge.

This study focused on preparation and characterization of two activated SiO2@C nanocomposites from rice-husk waste material through a controlled method. Both of them contain different percentages of silica and carbon. After chemical and thermal activations of the prepared composites, high energy ball milling was utilized to prepare nano powders. The percent of silica in the prepared nanocomposites was determined by HF method. Moreover, their chemical compositions were determined by XRF technique. The prepared materials were also examined by x-ray diffraction technique, FT-Infrared, scanning electron microscope, high resolution transmission electron microscope, Zeta Sizer, and Surface-Area-Analyzer. The prepared SiO2@C nanocomposite that contains higher silica percent was selected as adsorbent for removing of Cu, Zn and Pb from aqueous solutions. The effects of pH and contact time on the adsorption process were also studied. The results showed that SiO2@C nanocomposites with different percentages of silica and carbon were prepared successfully by the proposed method. The sample that contains higher silica, exhibited smaller particle size (20–50 nm), higher specific surface area (262.39 m2g-1) and higher negative zeta potential (−71 mV). On the other hand, the sample that contains lower silica exhibited higher particle size (20–70 nm), lower specific surface area (42.95 m2g-1), and lower zeta potential (-6 mV). The adsorption efficiencies of prepared SiO2@C nanocomposites at pH 6 for removing of Cu, Zn, and Pb from aqueous solutions were 96.5, 97, 9 and 88.66%, respectively. The kinetic study revealed that the adsorption process proceeded by pseudo-second order reaction.

This study aimed to evaluate the therapeutic efficacy of Emodin-loaded polymer lipid hybrid nanoparticles (E-PLNs) for breast cancer. The size, Zeta potential, surface morphology, encapsulation efficiency, stability, in vitro drug release of E-PLNs prepared by the nanoprecipitation method were characterized. The uptake, in-vitro cytotoxicities and apoptosis of free drug, E-PLNs were investigated against MCF-7 cells. The efficacy of E-PLNs in tumor bearing nude mice has also been studied.The average particle size of the experimentally prepared E-PLNs was (122.7±1.79) nm, and the encapsulation rate was 72.8%. Compared with free Emodin (EMO), E-PLNs showed greater toxicity to MCF-7 cells by promoting the uptake of EMO, and can promote the early apoptosis of MCF-7 cells. In addition to the morphological changes of apoptotic cells, the ratio of Bax/Bcl-2 was significantly increased, which indicated that E-PLNs can induce apoptosis in MCF-7 cells to achieve anticancer effect. Finally, E-PLNs significantly inhibited tumor growth by more than 60%, which may be related to its passive targeting effect on tumor site. Our results suggest that E-PLNs have shown good anti-breast cancer effect than free EMO. Moreover, the effect of E-PLNs on MCF-7 cells is mainly related to the induction of apoptosis.

Chitosan/fucoidan nanoparticles were created using two fucoidans from the Fucus evanescens algae. One of them was a regular fucoidan obtained for the first time from the alga harvested at the reproductive growth stage, using only standard extraction methods, without additional modifications. Its structure was established via NMR spectroscopy to consist of the repeating →3)-α-L-Fucp-(2,4SO3−)-(1 → 4)-α-L-Fucp-(2SO3−)-(1→ fragment. Such fragment also coustituted 55% of the other fucoidan's structure, however it also included long sequences of α-L-fucopyranose residues sulfated only at C2. The nanoparticles were re-dispersed in water and the influence of fucoidan/chitosan mass ratio on the nanoparticles' size and zeta potential was investigated. 3D models of the regular fucoidan and chitosan's sections were created and their molecular docking was performed, showing that either polymer could occupy the exterior of the complex, depending on their ratio. Thermodynamic parameters of fucoidan-chitosan binding process were accessed, with the results indicating that significant conformational changes of fucoidan and chitosan molecules take place during the interaction, presumably to allow for more effective binding.

The purpose of this research was to enhance the transdermal delivery of diclofenac sodium niosomal formulations. To characterise the obtained niosomes, SEM, XRPD, DSC and ATR-FTIR were employed. The size of the niosomes increased from 158.00 ± 6.17 to 400.87 ± 4.99 nm when cholesterol was incorporated into the formulations. It was observed that the zeta potential of niofenac varies from -25.40 ± 1.352 to -43.13 ± 1.171 mV when the cholesterol percentage decreased from 2% to 0.2%. The higher entrapment efficiency percentage (63.70 ± 0.18%) was obtained for the formulations with larger particle sizes and higher cholesterol content. The optimised niofenac formulation showed a controlled release fashion where 61.71 ± 0.59% of the drug released within 24 h. The results showed that the value of permeated diclofenac sodium through the skin layers was higher for the niofenac gel formulation (242.3 ± 31.11 µg/cm2) compared to simple gel formulation (127.40 ± 27.80 µg/cm2). Besides, niofenac formulation outperformed the anti-inflammatory activities in the formalin test compared to the control and diclofenac simple gel group. The licking time was significantly lower in both early (40.2 ± 7.3 s) and late stages (432.4 ± 31.7 s) for niofenac compared to conventional formulation (early stage 130.4 ± 8.73 s and late stage 660.6 ± 123.73 s). This study indicates that niosomal formulations can improve drug therapeutic effects by increasing drug delivery to specific sites.

The authors reported a potential candidate methylated mud snail protein (MeMsp) as an effective and eco-friendly flocculant to treat the high turbidity wastewater. MeMsp was obtained by extraction of mud snail protein (Msp) through isoelectric precipitation (PSC-IP) and then methylated via the esterification with side-chain carboxyl. Structural characterization of FT-IR, zeta potential and elemental analysis were carried out and further confirmed the successful of the methylation. Flocculation experiments with kaolin suspension simulated wastewater indicated that MeMsp-24 displayed more excellent flocculation efficiency at a low dosage. At the optimum dosage 27 mg/L, the maximum clarification efficiency of MeMsp-24 was 97.46% under pH 7.0. Furthermore, MeMsp-24 exhibited a wide flocculation window in the pH range 1.0–9.0, and faster sedimentation velocity and larger flocs size. In addition, MeMsp-24 exhibited 92.12% clarification efficiency in treating railway tunnel construction effluent. The flocculation kinetic and mechanism analysis revealed that the most effective particle collision occurred at the optimal dosage, with charge neutralization and adhesion playing irreplaceable roles in different environments, respectively. Therefore, through extraction and methylation modification, MeMsp could be a promising eco-friendly flocculant for high turbidity wastewater treatment. HIGHLIGHTS Synthesized a novel bio-flocculant methylated mud snail protein.; The protein-rich mud snail is fully utilized.; Methylation successfully improved the flocculation performance of mud snail protein.; Methylated mud snail protein achieved a significant turbidity removal for high turbidity wastewater treatment.; Methylated mud snail protein is completely environmentally friendly.

Magnesium phosphate cement (MPC) has been applied in grouting engineering due to its features of quick setting, high early-strength, and perfect volume stability. The rheological properties (RPs) of MPC, being vitally important for site operation, need to be studied further. Sodium tripolyphosphate (STP) is one type of high-efficiency retarders used in MPC. This study investigated the effects of STP content on the RPs of MPC pastes, and the mechanisms were studied by characterizing the zeta potential, 1H NMR relaxation signal, water film thickness, mineral changes, and electrical impedance. Experimental results indicate that the plastic viscosity (η) increases gradually and the yield stress (τ0) decreases firstly and then increases with increasing the STP content. The influencing mechanisms of STP need to be distinguished by analyzing η and τ0 respectively. The water film thickness and the amount of intermediate hydration products within 15 min of hydration is directly related to the change in η. The porosity and distribution of free water obtained from 1H NMR in MPC slurry are the dominant factor for τ0, and followed by the diffused double layer. It is noteworthy that zeta potential is not an effective measure for studying the RPs of MPC. Results of electrical impedance also explain the mechanisms of STP retarding the hydration and improving the early-term strength of MPC.

The addition of glycerin reduced the dielectric constant of the aqueous alumina suspension, increased the zeta potential of the alumina powder, thickened the electric double layer, and improved the dispersibility of an alumina suspension for aqueous gel-casting. The glycerin-added suspension can effectively avoid the agglomeration, so that the green body had a more uniform microstructure and a higher relative density. The simultaneous addition of magnesium nitrate, EDTA and glycerol in aqueous-based alumina slurry can effectively promote the homogeneity of green microstructure and hence obtaining the sintered sample with relative sintered density of 99.7% and the mean grain size and distribution of 1.20 ± 0.44 μm. The (pressure-less sintered) sample Mg + EDTA + Gly exhibited superior Vickers hardness comparable to the samples prepared using HP, HIP, and SPS due to the small grain size (1.2 μm) and high sintered density (99.7%).

In the present work, highly porous, pH-responsive, and biocompatible chitosan-based hydrogel beads were prepared through gamma-irradiated graft copolymerization technique using L-glutamic acid as the monomer. The glutamic acid grafted chitosan (CH-g-GA) hydrogel beads, loaded with the anti-cancer drug (Doxorubicin, Dox), were exploited for their potential application as anti-cancer drug delivery system. The grafting conditions were optimized by varying irradiation dose (kGy) and monomer concentration. Further, the hydrogel beads were analysed using FTIR, XRD, SEM, TGA/DSC, Zeta potential studies, BET analysis and their strength was determined using rheological analysis. The swelling characteristics of the beads were studied at various simulated body pH (2.1, 5.8, and 7.4) to study their pH-responsive behaviour. The in-vitro drug release from the beads was thus evaluated at pH 5.8, 7.4 using UV-visible spectroscopy. The highest swelling ratio (426%) and drug release (81.33% in 144 h) was observed at the pH of 5.8. The MTT assay was performed on HEK-293 cell-line to check their cytocompatibilty and the cell proliferation of Dox-loaded beads was studied on MCF-7 cell-line. A significant cytotoxicity against the cancer-cells was observed which further established their promising use in the controlled delivery of anti-cancer agents for localized cancer therapy.

This study sought to prepare a self-microemulsion drug delivery system containing zingerone (Z-SMEDDS) to improve the low oral bioavailability of zingerone and anti-tumor effect. Z-SMEDDS was characterized by particle size, zeta potential and encapsulation efficiency, while its pharmacokinetics and anti-tumor effects were also evaluated. Z-SMEDDS had stable physicochemical properties, including average particle size of 17.29 ± 0.07 nm, the zeta potential of -22.81 ± 0.29 mV, and the encapsulation efficiency of 97.96% ± 0.02%. In vitro release studies have shown the release of zingerone released by Z-SMEDDS was significantly higher than free zingerone in different release media. The relative oral bioavailability of Z-SMEDDS was 7.63 times compared with free drug. Meanwhile, the half inhibitory concentration （IC50）of Z-SMEDDS and free zingerone was 8.45 μg/mL and 13.30 μg/mL, respectively on HepG2. This study may provide a preliminary basis for further clinical research and application of Z-SMEDDS.

The present work aims to synthesize the pH-sensitive crosslinked guar gum-g-poly(acrylic acid-co-acrylonitrile) [guar-g-(AA-co-ACN)] via microwave-assisted technique for the sustained release of thymoquinone. The synthesized material [guar-g-(AA-co-ACN)] was optimized by varying synthetic parameters viz. monomer concentration, reaction time, and microwave power to obtain the maximum yield of the crosslinked guar gum grafted product as well as maximum encapsulation of thymoquinone. The synthesized material [guar-g-poly(AA-co-ACN)] was characterized by FT-IR, SEM, XRD, NMR, zeta potential, and thermal techniques. This synthesized material was used to encapsulate thymoquinone (TQ) for effective nanotherapeutic delivery. In-vitro thymoquinone release behavior of guar-g-poly(AA-co-ACN) based nanoparticles (NpTGG) was investigated. The maximum thymoquinone release (78%) was achieved at pH 7.4 and time (6 h). The NpTGG also exhibited better antioxidant activity and hemocompatibility as compared to thymoquinone. Cytotoxicity of uar-g-(AA-co-ACN) and NpTGG was also evaluated against the human kidney VERO cell line and found to be nontoxic. Current research provides a cost-effective and green approach for the synthesis of guar-g-(AA-co-ACN) and NpTGG for sustained release of thymoquinone.

Common collectors for rare earth mineral (REM) flotation, which include carboxylates and hydroxamates, face problems such as being non-selective and sensitive to impurity ions. A type of ionic liquid (IL), tetraethylammonium mono-(2-ethylhexyl)2-ethylhexyl phosphonate ([N2222][EHEHP]), has been investigated previously for rare earth elements (REE) solvent extraction, and was proven to be selective and effective. In this work, [N2222][EHEHP] was evaluated as a collector in bastnasite (a primary REM source for REE production) flotation for the first time. The results were compared with quartz and hematite, two common gangue minerals in REM deposits. Zeta potential measurements and Fourier-transform infrared spectroscopy (FT-IR) were completed to investigate the surface chemical properties involved in the flotation of these minerals using this collector. The findings were compared with microflotation results. FT-IR and zeta potential measurements suggest adsorption of the collector's phosphonate group onto bastnasite and hematite, likely through chemisorption; whereas for quartz, the minimum microflotation recovery is likely due to no adsorption of IL on its surface. Microflotation results show higher collectability of [N2222][EHEHP] for hematite than bastnasite, the latter only shows appreciable recovery at pH 5 with elevated dosage of IL (500 g/t). To achieve better separation, a two-stage flotation scheme was designed and evaluated by bench scale flotation on a synthetic mineral mixture. The concentrates and tails were analyzed by magnetic separation, and it is found that bastnasite recovery over 90% with maximum upgrade ratio 1.7 can be achieved with elevated collector dosage.

Plant viruses are major contributors to crop losses and induce high economic costs worldwide. For reliable, on-site and early detection of plant viral diseases, portable biosensors are of great interest. In this study, a field-effect SiO2-gate electrolyte-insulator-semiconductor (EIS) sensor was utilized for the label-free electrostatic detection of tobacco mosaic virus (TMV) particles as a model plant pathogen. The capacitive EIS sensor has been characterized regarding its TMV sensitivity by means of constant-capacitance method. The EIS sensor was able to detect biotinylated TMV particles from a solution with a TMV concentration as low as 0.025 nM. A good correlation between the registered EIS sensor signal and the density of adsorbed TMV particles assessed from scanning electron microscopy images of the SiO2-gate chip surface was observed. Additionally, the isoelectric point of the biotinylated TMV particles was determined via zeta potential measurements and the influence of ionic strength of the measurement solution on the TMV-modified EIS sensor signal has been studied., Deutsche Forschungsgemeinschaft (DFG, German Research Foundation), Projekt DEAL

Made available in DSpace on 2021-06-25T11:15:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-31 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The high incidence and costs of chronic wounds in the elderly have motivated the search for innovations to improve product performance and the healing process while reducing costs. In this study, bioadhesive nanostructured lipid carriers (NLC) were developed for the co-encapsulation of compounds with antioxidant (α-tocopherol and quercetin) and antimicrobial (tea tree oil) activity for management of wounds. The NLC was produced with shea butter and argan oil, and modified with sodium alginate or chitosan to confer bioadhesive properties. Spherical nanoparticles of ~307–330 nm and zeta potential varying from −21.2 to +11.8 mV were obtained. Thermal analysis demonstrated that the lipid matrix reduced tea tree oil thermal loss (~1.8-fold). Regardless of the type of polysaccharide employed, the NLCs promoted cutaneous localization of antioxidants in damaged (subjected to incision) skin, with a ~74 to 180-fold higher delivery into the skin compared to percutaneous delivery. This result is consistent with the similar bioadhesive properties of chitosan or sodium alginate-modified NLC. Nanoencapsulation of tea tree oil did not preclude its antimicrobial effects against susceptible and resistant strains of S. aureus and P. aeruginosa, while co-encapsulation of antioxidants increased the NLC-induced fibroblasts migration, supporting their potential usefulness for management of wounds. Instituto de Ciências Biomédicas Universidade de São Paulo School of Pharmaceutical Sciences São Paulo State University (UNESP) Faculdade de Ciências Farmacêuticas Universidade de São Paulo School of Pharmaceutical Sciences São Paulo State University (UNESP) CAPES: 001 FAPESP: 2013/16617-7 FAPESP: 2015/07993-0 FAPESP: 2017/19059-6 FAPESP: 2017/19374-9 FAPESP: 2018/13877-1 FAPESP: 2019/26048-6 CNPq: 306866/2020-0

Spray granulation was used to control morphology and particle size of raw materials for spheroidization in this work. Effects of dispersant (PAA-NH4OH) addition, pH value and solid content on stability of slurry for granulation was investigated. Influence of solid content of the slurry and atomizer speed on spray granulation were also investigated. Furthermore, difference in spheroidization effect between Ti-6Al-4V powder spheroidized from the granulated powder and irregular powder was compared. Results show that zeta potential of the slurry can be controlled at -44 mV to by addition of dispersant when pH value is 9.3. Granulated powder prepared with 50 wt% solid content and 10,000 rpm atomizer speed was best for plasma spheroidization. Ti-6Al-4V powder spheroidized from the granulated powder has better properties than that spheroidized from irregular powder. Spheroidization ratio, flow properties and apparent density of the spheroidized Ti-6Al-4V powder from granulated powder are 98%, 35.4 g/50s and 3.2 g/cm3, respectively.

Background The overall objective was to prepare a highly accurate nanocarrier system of mesalamine for the treatment of ulcerative colitis with increased therapeutic efficacy and targeting. In the formulation of nanocarrier systems, optimization is a critical process for understanding nanoformulation variables and quality aspects. The goal of the present work was to determine the effect of independent variables, i.e., the concentrations of chitosan, carboxymethyl inulin (CMI), and the drug on the response variables, i.e., particle size and percent entrapment efficiency of the mesalamine-loaded nanoparticle using the Box Behnken design (BBD). The correlation between the independent and dependent variables was investigated using the Design Expert generated mathematical equations, contour, and response surface designs. Result An optimized batch was developed using the ionotropic gel method with selected independent variables (A: + 1 level, B: 0 level, C: − 1 level) and the developed nanoparticles had a particle size of 184.18 nm, zeta potential 26.54 mV, and entrapment efficiency 88.58%. The observed responses were remarkably similar to the predicted values. The morphological studies revealed that the formulated nanoparticles were spherical, and the results of the FTIR and DSC studies indicated the drug-polymer compatibility. The nanoparticle showed less than 5% release in the pH 1.2. In the colonic region (pH 7.4), more than 80 % of the medication was released after 24 h. The kinetics study showed that the Higuchi and Korsemeyer-Peppas models had R2 values of 0.9426 and 0.9784 respectively, for the developed formulation indicating linearity, as revealed by the plots. This result justified the sustained release behavior of the formulation. Conclusion The mesalamine-loaded chitosan-CMI nanoparticle has been successfully developed using the ionotropic gelation method. The nanoparticles developed in this study were proposed to deliver the drug to its desired site. The developed nanoparticles were likely to have a small particle size with positive zeta potential and high percent drug entrapment. It could be stated from the results that BBD can be an active way for optimizing the formulation and that nanoparticles can be a potential carrier for delivering therapeutics to the colon.

The chemical conversion of the surface termination of 2D transition metal carbides/nitrides (MXenes) has opened up a design space that previously had not been extensively explored for this functional material. Herein, via a simple sealed thermal method, the amino terminated groups were successfully introduced on Ti3C2 MXene surface. The substitution reaction of amino group to hydroxyl group was proposed to elucidate this aminated process. As the amination would reduce the carrier density on the surface of MXene, the electrical conductivity of MXene-NH2 film decreased, while it still reached a high conductivity of 2.11 × 104 S m−1. This film also possessed an excellent electromagnetic interference shielding effectiveness of 16160 dB cm2 g−1. Importantly, although the introduction of amino termination altered Zeta potential value, Zeta potential sign remained negative and the MXene-NH2 exhibited excellent dispersity in water similar to that of traditional MXenes. Furthermore, the existence of covalent bonds endowed MXene-NH2 polymer composite film with improved mechanical properties. Compared with that of traditional CMC/MXene film, the tensile strength and fracture energy of CMC/MXene-NH2 increased by 65.5% and 132.7%, respectively. These results demonstrated that the introduction of amino terminated group on MXene surface would be an effective strategy to obtain higher performance MXene-based films.

This work investigates the effect of the surface charges of oil droplets and carbonate rocks in brine and in surfactant solutions on oil production. The influences of the cations in brine and the surfactant types on the zeta-potentials of both oil droplets and carbonate rock particles are studied. It is found that the addition of anionic and cationic surfactants in brine result in both negative or positive zeta-potentials of rock particles and oil droplets respectively, while the zwitterionic surfactant induces a positive charge on rock particles and a negative charge on oil droplets. Micromodels with a CaCO3 nanocrystal layer coated on the flow channels were used in the oil displacement tests. The results show that when the oil-water interfacial tension (IFT) was at 10−1 mN/m, the injection of an anionic surfactant (SDS-R1) solution achieved 21.0% incremental oil recovery, higher than the 12.6% increment by the injection of a zwitterionic surfactant (SB-A2) solution. When the IFT was lowered to 10−3 mM/m, the injection of anionic/non-ionic surfactant SMAN-l1 solution with higher absolute zeta potential value (ζoil + ζrock) of 34 mV has achieved higher incremental oil recovery (39.4%) than the application of an anionic/cationic surfactant SMAC-l1 solution with a lower absolute zeta-potential value of 22 mV (30.6%). This indicates that the same charge of rocks and oil droplets improves the transportation of charged oil/water emulsion in the porous media. This work reveals that the surface charge in surfactant flooding plays an important role in addition to the oil/water interfacial tension reduction and the rock wettability alteration.

Superparamagnetic nanoparticles are being used in cancer therapy as agents of MRI contrasting, drug delivery, and hyperthermia therapy. Their radiosensitization ability is less explored in comparison with gold and other high – Z nanoparticles. Herein, we report the radiotherapy application of Zn0.4Co0.6Fe2O4 superparamagnetic nanoparticles against HT-29 colorectal cancer cells. The nanoparticles were synthesized by the hydrothermal method and they were characterized using XRD, VSM, FTIR, DLS, FE-SEM, and XPS techniques. The nanoparticles have spherical morphology with a cubic spinel structure. The surface of the nanoparticles contains hydroxyl and carbonyl functional groups. The hydrodynamic mean size of the nanoparticles is 55.2 nm with a moderate zeta potential of 29.11 mV. The nanoparticles are superparamagnetic with a good saturation magnetization value of 73 emu/g. The cationic distribution study showed that the tetrahedral crystal positions are occupied by Co2+ and Fe3+ cations whereas the octahedral positions are occupied by Zn2+, Co2+, and Fe3+ with Fe3+ being the most. The cytotoxicity was investigated by MTT assay. The anticancer and radiosensitization ability of the nanoparticles was assessed by colony forming assay. The IC50 obtained from the cytotoxicity study is 100 μg/mL. The anticancer study showed 43% proliferation inhibition at 100 μg/mL. The combination of 2 Gy and nanoparticles resulted in more damage on colorectal cancer cells than 4 Gy alone in the radiosensitization study. The present investigation suggests that Zn0.4Co0.6Fe2O4 superparamagnetic nanoparticles are potential candidates to enhance the efficacy of radiotherapy in the case of colorectal cancer.

In this research, we adopt an ecofriendly and sustainable approach to compare the potentiality and efficiency of Phragmites australis aqueous extracts of two different organs to fabricate gold nanoparticles (AuNPs). The aqueous extracts of plant roots and rhizome were used as alternative reducing agents to conventional chemicals. Various Characterization techniques were used; UV–Vis spectroscopy, Zeta potential, Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Selected Area Electron Diffraction (SAED), Energy Dispersive X-ray Spectroscopy (EDX), High Resolution Transmission Electron Microscopy (HRTEM) equipped with elemental mapping in order to confirm the formation of zero-valent AuNPs, X-ray photoelectron spectroscopy (XPS). Our results demonstrated that both extracts of Phragmites australis are good candidates for the green-synthesis of AuNPs. Zeta potential was used to confirm the stability of AuNPs. The cytotoxic capacities of both AuNPs samples were validated using MTT assay which proved the inhibition of the growth and proliferation of human lung cancer cells (A549 cell line). Antioxidant potentialities were >10%. The phytosynthesized AuNPs exhibited high capacity in removing methylene blue and methyl orange dyes within just one min. This research offers an alternative solution to manage the accumulated unwanted biomass of a widely distributed aquatic macrophyte in aquatic ecosystems.

This study aimed to determine the effects of lignin characteristics (mainly molecular weight, functional groups, and internal linkages) on nanoparticle formation. First, five different lignin fractions (Mw 1460-12,900) were obtained from commercial kraft lignin (KL) by sequential solvent extraction. Functional groups and internal linkages were determined in lignin fractions, each fraction consisting of different levels and ratios. Second, spherical lignin nanoparticles (i.d. 193-1039 nm) were synthesized by nanoprecipitation at different pre-dialysis concentrations (1, 2, 4, and 6 mg mL-1 THF) with the different fractions (F1, F2, F3, F4, and F5). The study revealed that larger particles consisted of lignin fractions of lower molecular weight and higher phenolic group content (KL-F1 and F2), while smaller but non-uniform particles were produced from fractions of higher molecular weight and lower phenolic group content (KLF4 and F5). Every zeta potential value of the particle exceeded -35 mV. The nanoparticles from raw kraft lignin exhibited no significant cytotoxicity, hemotoxicity, and hypersensitivity. This study revealed that molecular weight and hydroxyl group content in the lignin highly correlated with nanoparticle properties. The present kraft lignin nanoparticles have potential for use in various polymer-based nanotechnology.

The present work reported synthesis, characterization, and biocompatibility of starch encapsulated silver nanoparticles (St-PF-AgNPs) and their antibacterial activity. The synthesis of St-PF-AgNPs involved in two steps: (i) synthesis of the biogenic silver nanoparticles using the fungal extracts (PF-AgNPs); and, (ii) encapsulation of starch in PF-AgNPs (St-PF-AgNPs). The surface plasmon resonance was found at 420 nm for the PF-AgNPs while it was at 260 and 420 nm for the St-PF-AgNPs. FTIR spectrum demonstrated the capping and encapsulation of the fungal extracts and starch in PF-AgNPs and St-PF-AgNPs. The XRD and TEM-EDS confirmed the crystalline nature, spherical-shaped , and polydispersed- PF-AgNPs and St-PF-AgNPs with strong signals of Ag. The St-PF-AgNPs showed a Z-average size of 115.2 d.nm and zeta potential of -17.8 (mV) as indicated by DLS and zeta potentials. The cytotoxicity results demonstrated higher toxicity of PF-AgNPs than St-PF-AgNPs in HEK293 cells. The antibacterial activity of St-PF-AgNPs were higher than PF-AgNPs in S. aureus. Overall, this work concluded that the starch encapsulation significantly increased the antibacterial activity of PF-AgNPs and this opens a new avenue for the treatment of bacterial infections through the sustained release of PF-AgNPs to target pathogenic bacterial cells.

Biological macromolecules are proven to be potential green corrosion inhibitors because of their outstanding structural features and eco-friendliness. This study is aimed at enhancing their corrosion mitigation capabilities by converting them into nanoparticles. This is the first work where nanoparticles of biological macromolecules are exploited for corrosion mitigation studies. Glycogen nanoparticles (GLY-Np) were synthesized by microwave�mediated nanoprecipitation method and characterized by ATR–FTIR, XRD, UV–Visible Spectroscopy, FESEM analysis, EDX, TEM, and Zeta potential measurements. They are used as an eco-friendly inhibitor for corrosion control of zinc in sulfamic acid (NH2SO3H). The electrochemical study was a primary experimental tool employed for corrosion rate measurement. Conditions were optimized to obtain maximum inhibition efficiency by varying concentrations of inhibitor and temperature. Activation and thermodynamic parameters were eval�uated and discussed in detail. A suitable adsorption isotherm was proposed to fit the experimental results. Adsorption of the inhibitor was confirmed by SEM, EDX, and AFM techniques. The inhibition efficiency of 92% was obtained for 0.02 gL− 1 GLY-Np. Thus, GLY-Np turned out to be an effective green inhibition with economic benefits