Spherical Shape Research Articles

Berberine-Loaded PVCL-PVA-PEG Self-Assembled Micelles for the Treatment of Liver Fibrosis.

Liver fibrosis is a necessary pathological process in many chronic liver diseases. Studies have shown that the progression of chronic liver disease can be slowed by rational intervention in hepatic fibrosis. Berberine (BBR), a natural extract of Phellodendron amurense, inhibits the development of liver fibrosis through several mechanisms. However, the clinical application of BBR is limited due to its low solubility. Drug delivery systems have been developed to improve the solubility of hydrophobic drugs and increase their efficacy in treating the liver fibrosis. In this study, a biocompatible nanomicelle was constructed by thin-film dispersion method using polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (PVCL-PVA-PEG) as a carrier to encapsulate BBR (PVCL-PVA-PEG/BBR-MCs) to improve the solubility of BBR and reduce the systemic side effects. The ability to inhibit HSC-T6 cell activation of PVCL-PVA-PEG/BBR-MCs was evaluated in vitro. The anti-hepatic fibrosis effects of PVCL-PVA-PEG/BBR-MCs were investigated in vivo. PVCL-PVA-PEG/BBR-MCs have a uniform spherical shape with a mean particle size of 60.04 ± 0.027 nm and a potential of 1.49 ± 0.32 mV. It had an encapsulation efficiency of 98.52% ± 0.70 and drug loading content of 6.16% ± 0.04. Compared to free BBR, PVCL-PVA-PEG/BBR-MCs significantly inhibited HSC-T6 cell activation and TGF-β1-induced HSC-T6 cell migration in vitro. In vivo biodistribution experiments showed significantly improved hepatic distribution of PVCL-PVA-PEG/DiD-MCs compared to free DiD, suggesting that PVCL-PVA-PEG micelles enhance the ability of BBR to enter the liver and improve therapeutic efficacy. After treatment, PVCL-PVA-PEG/BBR-MCs significantly improved fibrotic liver structure and reduced collagen deposition in comparison to the CCl4-treated group; the treatment outcome was more effective than that of the free BBR group. Our results demonstrate the advantages of encapsulating BBR in PVCL-PVA-PEG micelles and highlight the potential of PVCL-PVA-PEG/BBR-MCs as a therapeutic strategy for the treatment of liver fibrosis.

Facile synthesis of SSZ-16 nanoaggregates with excellent performance in NH3-SCR reaction

d6r units were proved to be crucial for the synthesis of SSZ-16 zeolite with AFX topology, and FAU zeolite owning plenty of d6r units was chosen as the essential raw material for constructing AFX frameworks. In this work, SSZ-16 zeolite was directly synthesized using colloidal silica and sodium aluminate as the raw materials in short crystallization time of 5 h. The corresponding crystallization process were carefully investigated by various characterizations, demonstrating that the key to this success was the formation of d6r units built up by a large amount of s4r units which were formed with the assistance of the appropriate organic structure directing agent (OSDA) and seeds in the synthetic media. Interestingly, the products of C-SSZ-16 zeolites presented spherical shapes consisted of relatively small particles with size range from 30 to 50 nm. Moreover, after ion-exchanged with Cu ions, the Cu-C-SSZ-16 products showed excellent performance in the selective catalytic reduction of NOx with NH3 (NH3-SCR) and better hydrothermal stability than conventional Cu-SSZ-16-con samples due to slightly higher Si/Al ratio of the Cu-C-SSZ-16. Therefore, remarkable catalytic performance and the use of low-cost raw materials as well as short period of synthesis time make AFX zeolites as potential applicants in NH3-SCR field, from an industrial viewpoint.

Eco‐friendly Green Synthesis of Silver Nanoparticles Using Daphne Mucronata Royle Seeds Extract and the Potential Antibacterial, Antifungal, and Scolicidal Activities

AbstractGreen synthesized silver nanoparticles (AgNPs) have received lots of attention due to being used as potential therapeutic agents. For the first time, this research investigated the biosynthesis of silver nanoparticles using the extract of Daphne mucronata seeds, which are rich in phenolic and polyphenolic substances and evaluated their antibacterial, antifungal, and scavenging activities. The process of nanoparticle (NPs) preparation was confirmed using UV–vis spectroscopy with an absorption peak at a wavelength of 440 nm. Dynamic light scattering (DLS) was used to determine the particles' distribution. Fourier‐transform infrared spectroscopy (FTIR) validated the functional groups contributing to the reduction of Ag+ to Ag. Moreover, X‐ray diffraction analysis (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) approved the crystalline nature and spherical shape of the particles with mean and standard deviation of particle size to be 60.25 and 24.88 nm, respectively. The antibacterial, antifungal, and scolicidal activities of AgNPs were studied using disc diffusion against four standard bacteria species and microdilution methods for four Candida strains. The greatest effect of AgNPs with the highest concentration (80 µg/mL) was observed on Staphylococcus aureus (22.26 mm) and the lowest on Pseudomonas aeruginosa (19.07 mm). In the case of Candida fungus, the highest effect of AgNPs was reported for Candida krusei (7.93 µg/mL) and the lowest for Candida albicans (63.49 µg/mL). Also, these nanoparticles were able to register 100% lethality on the Echinococcus granulosus parasite in 15 min at a concentration (80 µg/mL). Therefore, the production of AgNPs as a renewable and cheap material can be effective after performing all the necessary tests as antibacterial, antifungal and antiparasitic agents with the least side effects in biomedical and pharmaceutical sciences.

Synergistic impact of lanthanum and cerium co-doping ZnO for improved photocatalytic rhodamine B degradation efficiency under UV light

In this study, the influence of different La and Ce co-doping amounts on the structural, morphological, optical, and photodegradation properties of ZnO nanostructures was evaluated. Zn1-2xLaxCexO nanoparticles (NPs) were prepared using sol-gel auto-ignition process, where x = 0.00 (pure ZnO), 0.01 (LC1), 0.03 (LC3), and 0.05 (LC5). The X-ray diffraction (XRD) and Raman results revealed that the prepared ZnO NPs crystallize in the hexagonal wurtzite structure. The size of crystallites is affected by the increment of La and Ce and it decreased from 24.29 nm to 10.40 nm with the increase in the concentration of La and Ce. Transmission electron microscopy (TEM) showed that the samples exhibit an irregular distribution of NPs with a dominant spherical shape morphology. The simultaneous incorporation of La and Ce in ZnO NPs led to a slight variation in the absorption edge and a slight shift in the values of the band gap energy from 3.20 to 3.24 eV. Furthermore, a reduction in the recombination rate of photogenerated charge carriers and the creation of fewer additional defects upon the appropriate insertion of Ce and La ions are highlighted by the analysis of photoluminescence spectra, Nyquist plots, and transient photocurrent measurements. The photocatalytic activity of samples was evaluated against rhodamine B organic dye under UV light irradiation. The analysis showed that LC1 sample exhibited superior photocatalytic performance with 99.1% degradation efficiency and a degradation rate constant of 0.0762 min-1. This enhancement has been ascribed to the surface defects and the optimized crystallite size achieved, which help to generate reactive entities such as •OH and O2•− in addition to the great role of holes (h+) and impede the recombination of charge carriers e-/h+.

Tangerine fruit peel extract mediated biogenic synthesized silver nanoparticles and their potential antimicrobial, antioxidant, and cytotoxic assessments

Abstract The utilization of plant bioactive composites has concerned substantial attention due to their possible use in the development of novel antibiotics, containing the environmentally sustainable synthesis of nanoparticles. In the current study, a green and eco-friendly process was employed to synthesize silver nanoparticles (Ag-NPs) and to evaluate their anti-bacterial, anti-oxidant, and anti-cancer potentials. The characterization of the Ag-NPs involved UV-vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The UV-vis spectrum of Ag-NPs was 437 nm. The FTIR absorption peaks detected at 685.48 cm−1 confirmed their characteristics. The FESEM displayed that Ag-NPs have an average size of 30 nm. The TEM revealed that the Ag-NPs have an irregular spherical shape with 16 nm size distribution. The XRD results provided a strong indication that the green synthesized Ag-NPs was of high purity with crystalline nature. The anti-bacterial properties were investigated at different concentrations for both the ethanolic tangerine peel extract and Ag-NPs. The results of anti-bacterial activity showed that 100 µg·mL−1 was potent concentration, but the Ag-NPs were more effective than the ethanolic tangerine peel extract. For the ethanolic extract, the inhibition zone was 17.50 ± 0.20 mm for K. pneumoniae and 14.40 ± 0.20 mm for B. cereus. For the Ag-NPs, the inhibition zone was 25.50 mm for K. pneumoniae and 20.50 mm for B. cereus. Furthermore, the antioxidant examination revealed more potent free radical scavenging activity of the Ag-NPs than the ethanolic peel extract alone. The ethanolic extract ranged 46–77% while the Ag-NPs ranged 57–88%. Additionally, the anti-proliferative of the Ag-NPs against the lung cancer cell line (A549) was more potent than the ethanolic extract alone. The cytotoxic activity was 90.03% and 78.50%, respectively. The anti-proliferative effect of Ag-NPs is attributed to cell death, induced apoptosis, and enhanced generation of reactive oxygen species. Our findings highlight the potential and further utilization of Ag-NPs in medicinal applications particularly for cancer therapeutics.

Fabrication of curcumin-loaded nano-micelles based on quercetin-quarternary ammonium-chitosan (Qu-QCS) conjugate and evaluation of synergistic effect with doxorubicin against breast cancer.

The applications of quarternized chitosans have achieved notable success in the development of drug-delivery systems. This study reported the preparation of quercetin-quarternized chitosan (Qu-QCS) conjugate and its application for the fabrication of stable and safe curcumin (cur) loaded nano-micelles with high targeting ability and selectivity towards the breast cancer cell lines. Moreover, doxorubicin (dox) was co-treated with the nanomicelles to enhance the efficacy and reduce the cardiotoxic effects of dox. Structural properties of Qu-QCS were evaluated by FTIR, DSC, and XRD analysis and the yield obtained was 48.82%. The nano-micelles obtained showed spherical shape, <200nm size, 48.38% entrapment efficiency, prolonged stability at 4°C and pH-responsive release pattern. The cur-loaded nano-micelles showed higher activity and selectivity against breast cancer (MCF-7 and MDA-MB-231) cell lines with enhanced internalization, lower toxicity to the normal cardiomyoctyes (H9C2), enhanced the cell cycle arrest at the G2/M phase of the breast cancer cell lines and induced apoptosis with high intensity compared to pure cur. Moreover, the co-treatment of dox with cur-loaded Qu-QCS nano-micelles showed increased anticancer activity and reduced cardiotoxicity. Overall, this study suggests the potential applications of cur-loaded Qu-QCS micelles in the delivery of chemotherapeutic agents and complementary support in combination with chemotherapeutic agents.

Versatile Hybrid Magnetic core silver-shell (Fe3O4@PEI@Ag) Microspheres based SERS Substrates for Detection of Organic Dyes Pollutant

In recent years, the development of highly sensitive and versatile substrates for Surface-Enhanced Raman Scattering (SERS) has become pivotal in environmental monitoring. This study introduces a hybrid SERS substrate designed to enhance the detection and discrimination of organic dyes in aqueous environments. In this report, we present silver shell magnetic core (Fe3O4@PEI@Ag) microspheres as a versatile SERS substrate for the detection and differentiation of organic dyes, specifically malachite green (MG), crystal violet (CV), Rhodamine 6G (R6G), and Safranin O (S.O), which are often overlooked water pollutants. The core-shell structure of Fe3O4@PEI@Ag microspheres have been synthesized via seed-mediated growth method. The microspheres, integrates a magnetic core of iron oxide (Fe3O4) through a polymeric layer of polyethyleneimine (PEI) with silver shell (Ag), are optimized to act as magnetic separator and show SERS activity. The SEM measurements confirm the spherical shape of grown nano-particles whereas magnetization experiments confirm the presence of magnetic cores as well non-magnetic layers coating in the end products. These microspheres with aluminium (Al) base combination demonstrate high SERS sensitivity with enhancement factor of 1 × 105, 5.6 × 106, 6.4 × 106, and 4.2 × 105 for MG, CV, R6G, and S.O respectively. The detection limits have been found in the range between 10-8-10-10 for all four dyes. A linear relationship between Raman intensity and concentrations of dyes make it suitable for quantitative analysis of unknown concentration. Principal component analysis (PCA), a multivariate analysis has been adopted to discrimination of dyes. These dyes have been effectively detected quantitative in tap water to express substrate's suitability in real-world application. Their dual functionality, as SERS-active substrate and as magnetic separator, enhances their utility in real-world applications such as organic contaminants in aquatic environments.

Voltammetric determination of uric acid using a miniaturized platform based on screen-printed electrodes modified with platinum nanoparticles

Disposable and sensitive screen-printed carbon electrodes (SPCE) modified with multi-walled carbon nanotubes (MWCNT) and platinum nanoparticles (PtNPs) were constructed to analyse uric acid (UA) in biological samples using a miniaturized smartphone potentiostat system. Combining the nanomaterials with Nafion® yielded a stable dispersion that could be successfully used as an electroactive layer. Transmission electron microscopy (TEM) and energy dispersive scanning (EDS) were used to characterize the morphology of PtNPs. These revealed approximately spherical shapes with emission lines characteristics of platinum. Furthermore, PtNPs/MWCNT/SPCE film was characterized by scanning electron microscopy (SEM), which demonstrated the tubular characteristic of MWCNT distributed and covered by carbon black (CB) spheres present in the screen-printed ink. An enhanced current response was observed for UA voltammetric analysis, especially due to the synergism effect of PtNPs and MWCNT, which reduced the Rct value. The values of Dapp (1.6 × 10−6 cm−2 s−1) and kcat (2.76 × 103 mol−1 L/s) were determined for UA using the proposed sensor. The sensor displayed linear response for UA in the range from 5.0 × 10−6 mol/L to 6.9 × 10−4 mol/L, with a detection limit of 4.9 × 10−7 mol/L. Along with detectability, excellent performances were verified in terms of repeatability, anti-interference features, and analysis of UA in the biological samples.

Formulation Optimization and Evaluation of Patented Solid Lipid Nanoparticles of Ambrisentan for Pulmonary Arterial Hypertension.

Ambrisentan is a new endothelin receptor antagonist extensively used to manage pulmonary or pulmonary arterial hypertension. The therapeutic efficacy of Ambrisentan is limited due to its reduced solubility, higher log P (3.4), and thus less bioavailability. The recent investigation was concentrated on the improvement of solubility, and bioavailability of Ambrisentan for the therapy of hypertension via solid lipid nanoparticles (SLN) administered orally. XRD evaluated the compatibility of Ambrisentan with lipids with FTIR, DSC, and crystalline nature. The SLN was developed by High-pressure homogenization method. The Glyceryl monostearate and Tween 80 indicated the highest solubility, hence selected. The optimization was performed with Box-Behnken Design considering the concentration of GMS (X1), Tween 80 (X2), stirring speed (X3) as independent factors and particle size (Y1), entrapment efficiency (Y2) as dependent factors. The Patents on the SLN are Indian 202321053691, U.S. Patent, 10,973,798B2, U.S. Patent 10,251,960B2, U.S. Patent 2021/0069121A1 and U.S. Patent 2022/0151945A1. The optimized batch F1 showed particle size (130 nm), ZP (-18.9 mV), and entrapment efficiency (85.73 %). The dual release pattern (prompt and sustained) was achieved with the SLNloaded Ambrisentan for about 24 hours. The lyophilized sample was subjected to SEM, which also revealed a spherical shape of a colloidal dispersion with a particle size of 126 nm. Hence, the F1 batch is highly recommended for solid oral delivery and also for the pilot-plant scale-up. A marked improvement in the solubility and dissolution of Ambrisentan was attained with the SLN. Moreover, the sustained delivery via the oral route enabled the patient's comfort, compliance, and therapeutic efficacy.

Investigation on the structure and thermal properties of HDPE/Ta2O5-based nanocomposites

This work reports on the influence of tantalum oxide nanoparticles on the structure and thermal properties of HDPE + Ta2O5 based polymer nanocomposites prepared by ex-situ solution casting method. XRD analysis confirmed the orthorhombic structure of Ta2O5 nanoparticles and an increase in the degree of crystallinity of HDPE/Ta2O5 based nanocomposites after the introduction of Ta2O5 into the HDPE matrix. SEM analysis showed that Ta2O5 nanoparticles were distributed over the surface of the sample in a spherical shape. FT-IR analysis confirmed the presence of Ta –O-Ta stretching vibration bands at 557 cm−1, 584 cm−1, 599 cm−1, 614 cm−1 and Ta-O bands at 824 cm−1, 828 cm−1 for HDPE/3-7 wt%Ta2O5 nanocomposites. The results indicate that small amounts of Ta2O5 nanoparticles (3–7 wt.%) introduced into HDPE act as nucleating agents, which enhance the thermal properties of the HDPE/Ta2O5 nanocomposite. Additionally, the properties of the polymer nanocomposite are influenced by both the structural changes in the polymer matrix and the interactions at the nanoparticle-polymer interface.

Bactericidal effects of silver nanoparticles prepared by green synthesis

This work aims to paper silver nanoparticles (AgNPs) using the green synthesis method, considered a low-cost and environmentally friendly method, and to study the structural properties of these nanoparticles by X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscopy (AFM) measurements. The results of XRD show that the AgNPs are polycrystalline in the dominant direction (122) (111), (200) (220) (311). By studying the surface morphology, the AFM results showed that the average particle size of the AgNPs is (6.73 nm). In contrast, the SEM results showed that the AgNPs have a spherical shape, and the average particle size is (52.532 nm). The chemical signature of AgNPs was known through FTIR measurement and was found to consist of a group of organic compounds. Through biological application, AgNPs were found to be effective in killing Escherichia coli, which is usually present in contaminated water and infects the intestines of humans and animals. That allows the AgNPs to effectively reduce many human diseases caused by these types of bacteria.

Optimization of Mesoporous Silica Nanoparticles of Silymarin through Statistical Design Experiment and Surface Modification by APTES

ABSTRACT: The major goal of this study was to create surface-modified mesoporous silica nanoparticles (MSN) of Silymarin, which has a short half-life and requires regular dosing due to first-pass metabolism. MSN was prepared by cost effective Sol-Gel method, functionalized by (3-Aminoprpyl) triethoxysilane (3-APTES). Evaluated and compared the Silymarin-loaded MSN and APTES functionalized MSN for drug loading, in-vitro dissolution, particle size, surface morphology, surface area, pore size and volume. The percent drug loading and encapsulation efficiency of APTES-functionalized MSN were found to be 92.50±0.72 % percent and 93.20±0.13 %, respectively, which showed a higher value in APTES-functionalized MSN as compared to Silymarin-loaded MSN. Drug release of APTES-functionalized MSN was 92.15 0.03%, which was more as compared to silymarin-loaded MSN. XRD showed that after functionalization silymarin changed from crystalline to amorphous form. SEM indicates that MSN was formed in a spherical shape with particle size of 196.7nm. The BET analysis proved that the nanoparticles had a larger surface area, which was reduced after drug loading and functionalization. Also, the pore size was increased and the pore volume was reduced after functionalization, indicating the incorporation of silymarin. The results suggested that the functionalization might successfully increase adsorption capacity, larger surface area, and increased encapsulation. Mesoporous silica nanoparticles also showed a greater impact on dissolution.

Bactericidal effects of silver nanoparticles prepared by green synthesis

This work aims to paper silver nanoparticles (AgNPs) using the green synthesis method, considered a low-cost and environmentally friendly method, and to study the structural properties of these nanoparticles by X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscopy (AFM) measurements. The results of XRD show that the AgNPs are polycrystalline in the dominant direction (122) (111), (200) (220) (311). By studying the surface morphology, the AFM results showed that the average particle size of the AgNPs is (6.73 nm). In contrast, the SEM results showed that the AgNPs have a spherical shape, and the average particle size is (52.532 nm). The chemical signature of AgNPs was known through FTIR measurement and was found to consist of a group of organic compounds. Through biological application, AgNPs were found to be effective in killing Escherichia coli, which is usually present in contaminated water and infects the intestines of humans and animals. That allows the AgNPs to effectively reduce many human diseases caused by these types of bacteria.

Structural, Magnetic and Electrochemical Properties of Nickel Manganese Ferrite (NixMn1-xFe2O4) Nanoparticles Prepared via Coprecipitation Method

In current work, the co-precipitation approach was effectively used to synthesize NixMn1-xFe2O4 nanoparticles. Thermal stability of the nickel manganese ferrite nanoparticle was observed at temperatures above 390 ºC by TG/DTA analysis. XRD investigation revealed the cubic structure of the synthesized NixMn1-xFe2O4 nanoparticles. The average crystallite size of synthesized nanoparticles determined via Scherrer’s equation, increases linearly with calcination temperature and nickel concentration. The FTIR spectra showed the existence of stretching vibrations of metal oxide, which are ascribed to the formation of nickel manganese ferrite nanoparticles. The surface morphology of NixMn1-xFe2O4 nanoparticles, as observed using FESEM, exhibited a spherical shape. The EDX spectrum indicates the occurrence of Ni, Fe, Mn and O in the synthesized nickel manganese ferrite nanoparticles. The average size of the crystallites, as determined by XRD, closely matches the analysis conducted using HRTEM. The magnetic properties of NixMn1-xFe2O4 nanoparticles were analyzed using VSM. Nickel manganese ferrite nanoparticles exhibit increasing saturation magnetization and coercivity values as nickel concentration increases, indicating soft ferrimagnetic properties and making it appropriate for high-density recording devices. The cyclic voltammetry investigation of Ni0.7Mn0.3Fe2O4 sample, calcinated at 600 ºC, reveals a significant specific capacitance of 590 F g–1 at a scan rate of 2 mV s–1, suggesting its potential use in supercapacitors.

Colloidal Characteristics of Poly(L-Lactic Acid)-b-Poly (ε-Caprolactone) Block Copolymer-Based Nanoparticles Obtained by an Emulsification/Evaporation Method.

Poly(L-lactic acid) (PLLA) and poly(ε-caprolactone) (PCL), two biodegradable and biocompatible polymers that are commonly used for biomedical applications, are, respectively, the result of the ring-opening polymerization of LA and ε-CL, cyclic esters, which can be produced according to several mechanisms (cationic, monomer-activated cationic, anionic, and coordination-insertion), except for L-lactide, which is polymerized only by anionic, cationic, or coordination-insertion polymerization. A series of well-defined PLLA-b-PCL block copolymers have been obtained starting from the same PLLA homopolymer, having a molar mass of 2500 g·mol-1, and being synthesized by coordination-insertion in the presence of tin octoate. PCL blocks were obtained via a cationic-activated monomer mechanism to limit transesterification reactions, and their molar masses varied from 1800 to 18,500 g·mol-1. The physicochemical properties of the copolymers were determined by 1H NMR, SEC, and DSC. Moreover, a series of nanoparticles (NPs) were prepared starting from these polyester-based copolymers by an emulsification/evaporation method. The sizes of the obtained NPs varied between 140 and 150 nm, as a function of the molar mass of the copolymers. Monomodal distribution curves with PDI values under 0.1 were obtained by Dynamic Light Scattering (DLS) and their spherical shape was confirmed by TEM. The increase in the temperature from 25 to 37 °C induced only a very slight decrease in the NP sizes. The results obtained in this preliminary study indicate that NPs have a temperature stability, allowing us to consider their use as drug-loaded nanocarriers for biomedical applications.

Carbonate Nanoparticles Formed by Water–Rock Reactions in Groundwater: Implication of Carbonate Rock Weathering in Carbonate Aquifers

Carbonate rocks are highly reactive and exhibit higher ratios of chemical weathering compared to most other rock types. A chemo-mechanical mechanism, which is particularly effective in groundwater due to higher ion concentrations, is common in fine-grained carbonates at the nanoscale. As a result, the weathering of carbonate aquifers produces a substantial number of carbonate nanoparticles (CNPs). In this study, we utilized high-resolution transmission electron microscopy (HRTEM) to analyze CNPs formed by water–rock reactions in two types of groundwater from Shandong Province, China. Our findings reveal a significant presence of naturally occurring CNPs in groundwater. The HRTEM results show that CNPs display spherical, cubic, hexagonal, and irregular shapes, with some forming aggregates. Energy-dispersive spectrometry indicates that most nanoparticles contain O, C, Ca, and Fe, with some also containing Si, Mg, S, Sr, and Cl. Selected area electron diffraction (SAED) patterns show that CNPs are mainly amorphous, with some crystalline forms. The diverse shapes and complex compositions of these CNPs suggest that they are not man-made but formed through the weathering of carbonate minerals via chemo-mechanical mechanisms. This discovery provides new insights into carbonate mineral evolution and mineralization during weathering. Given their widespread presence, CNPs in groundwater could represent the transportation of elements in the form of particles.

Water purification and biological efficacy of green synthesized Co/Zn-Doped α-Fe2O3 nanoparticles

In the present study, Co/Zn doped α-Fe2O3 (Hematite) nanoparticles (NPs) were synthesized using polyvinylpyrrolidone (PVP) and Azadirachta indica (AI) leaves aqueous extract. The analytical techniques including XRD, UV, SEM, EDX, VSM, Raman, and FTIR, we were able to identify and characterize the structural, morphological and magnetic attributes of the synthesized NPs. The findings demonstrated that the synthesized NPs exhibit homogeneous spherical shapes with particle sizes ranging from 8.64 to 15.32 nm. The NPs have rhombohedral crystal lattices, with crystallite sizes of 23.25 nm for chemically synthesized doped α-Fe2O3 NPs and 12.52 nm for those synthesized using green methods. The magnetic study has shown that the saturation magnetization (Ms) value of NPs, which ranges from 36 to 45 emu/g at ambient temperature, exhibits superparamagnetic properties (300 K). The treatment of industrial wastewater and its reuse for agricultural purposes are the subjects of the current study. Different concentrations of doped α-Fe2O3 NPs were used as photocatalysts to degrade dyes in a bioreactor under UV light in a heterogeneous mixture. The degradation rates achieved were 96.42 % for Congo Red (CR) and 98.36 % for Eosin Yellow (EY). DPPH assays were conducted to evaluate the antioxidant activity of the synthesized doped α-Fe2O3 NPs. The percentage inhibition of DPPH radicals ranged from 71.13 % to 90.35 %. Our findings indicate that AI leaf extract holds promise as a valuable resource for the development of bioactive compounds and environmentally friendly approaches to synthesizing green NPs. This is primarily attributed to the increased accessibility of bioactive components with potent antioxidant properties. The combination of these benefits provides opportunities for novel uses in environmental cleanup, biological applications, and energy conversion.

Orange peel-mediated synthesis of silver nanoparticles with antioxidant and antitumor activities

Orange (Citrus sinensis L.) is a common fruit crop widely distributed worldwide with the peel of its fruits representing about 50% of fruit mass. In the current study, orange peel was employed to mediate the synthesis of silver nanoparticles (AgNPs) in a low-cost green approach. Aqueous extracts of suitably-processed peel were prepared using different extraction methods; and their phytochemical profile was identified. Based on phytochemical screening, amount of main phytochemicals, free radical-scavenging ability, reducing power and antioxidant activity, the peel extract prepared by boiling seemed to be the most promising. Thus, major compounds of this extract were identified by gas chromatography-mass spectrometry. Potency of the peel extract to mediate the synthesis of AgNPs was then monitored by visual observation, UV-visible spectroscopy, energy dispersive X-ray analysis, transmission electron microscopy and zetametry. Color change of the reaction mixture to brown and absorption peak at 450 nm indicated AgNPs formation. Characterization of AgNPs revealed spherical shape, size of 30–40 nm, zeta potential of -18.2 mV and yield conversion of 82%. The as-synthesized AgNPs had antioxidant capacity (free radical-scavenging ability, reducing power and antioxidant activity) lower than that of the orange peel extract. However, these biogenic AgNPs had antitumor activity (IC50 of 16 ppm against HCT-116 and 1.6 ppm against HepG2 cell lines) much higher than the peel extract that was completely non-toxic to the considered cell lines.

Antibacterial Efficacy of AgNPs synthesized from Aloe vera extract and Staphylococcus aureus Culture Supernatant

Biological synthesis of silver nanoparticles (AgNPs) is an emerging method that avoids the need for costly equipment and hazardous chemicals. Therefore, in this study, Aloe vera (AV) extract and culture supernatant of Staphylococcus aureus (CS-S. aureus) were used to reduce and stabilise silver nanoparticles. The NPs were characterized using UV–vis spectrophotometry at 445 nm for AV-AgNP and 444.5 nm for CS-S.aureus AgNP, and the presence of silver was confirmed by energy dispersive X-ray (EDX). Furthermore, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the AV-CS of S. aureus-AgNPs had irregular and spherical shapes, with average sizes of 18.5 nm for AvAgNPs and 7.03 nm for CS-S. aureus-AgNPs. Additionally, the minimum inhibitory concentration (MIC) of both AgNPs showed a similar reaction. K. pneumoniae, P. aeruginosa, and S. epidermidis were more sensitive to the AgNPs compared to methicillin-resistant Staphylococcus aureus (MRSA). In conclusion, our study used a green method to synthesise silver nanoparticles using AV extract and CS of S. aureus. The NPs showed a remarkable antibacterial effect, especially CS-S. aureus-AgNP, which could have application as a treatment against both Gram-positive and Gram-negative bacteria.

Morphology and elemental composition of individual solid dust particles: From different sources to the atmosphere

This study investigates the morphology and elemental composition of individual solid dust particles from various sources (e.g., thermal power plant, domestic coal combustion, building construction dust, wind-blown dust, Asian dust storm, and road related dust) to the atmosphere under high and low relative humidity (RH) conditions in a coastal city of north China by using high-resolution electron microscopes. The results showed that distinct variations between dust particles from thermal power plant and domestic coal combustion, despite both using coal as fuel. Specifically, 88.6% (by number) of thermal power plant particles were spherical, whereas only 2 out of 347 particles from domestic coal combustion exhibited a spherical shape. Furthermore, domestic coal combustion particles showed a higher proportion of Ca-rich particles compared to those from thermal power plant. The wind-blown dust and Asian dust storm particles were mainly “Si + Al” subtype (52.0% v.s. 75.3%) and Si-dominant subtype (16.4% v.s. 11.7%) particles, which were mainly from crustal sources. However, wind-blown dust contained a higher fraction of Ca-rich (11.6%) and Fe-rich (5.3%) particles than Asian dust. The building construction dust particles primarily consisted of irregular Ca-dominant (39.4%) and “Ca + Si” subtype (29.8%) particles. Road related dust were also mainly Si-rich particles (52.9%), likely from re-suspended soil, along with a notable presence of spherical (8.0%) and Fe-rich particles (19.3%), possibly linked to vehicle emissions and brake wear. Additionally, relative number percentage of Na-rich particles and the average weigh ratios of Na in the atmospheric particles were higher than those from all above-mentioned source samples, suggesting that sea-salt related particles might be an important source of the atmospheric dust at the coastal city. The results indicated that Ca-rich particles were significantly modified by S and NaCl particles might lose Cl through heterogeneous reactions under higher RH.