Search Results (26)

The blood–brain barrier (BBB) limits drug delivery to the brain, particularly for large or hydrophilic molecules. Brain microvascular endothelial cells (bEND.3), which form part of the BBB, play a critical role in regulating drug uptake. This study investigates the use of cold atmospheric microplasma (CAM) to enhance membrane permeability and facilitate drug delivery in bEND.3 cells. CAM generates reactive oxygen species (ROS) that modulate membrane properties. We exposed bEND.3 cells to CAM at varying voltages (3, 3.5, 4, and 4.5 kV) and measured drug uptake using the fluorescent drug FD-150, fluorescence intensity, ROS levels, membrane lipid order, and membrane potential. The results showed a significant increase in fluorescence intensity and drug concentration in the plasma-treated cells compared to controls. ROS production, measured by DCFH-DA staining, was higher in the plasma-treated cells, supporting the hypothesis that CAM enhances membrane permeability through ROS-induced changes. Membrane lipid order, assessed using the LipiORDER probe, shifted from the liquid-ordered (Lo) to liquid-disordered (Ld) phase, indicating increased membrane fluidity. Membrane depolarization was detected with DisBAC2(3) dye, showing increased fluorescence in the plasma-treated cells. Cell viability, assessed by trypan blue and LIVE/DEAD™ assays, revealed transient damage at higher voltages (≥4 kV), with recovery after 24 h. These results suggest that CAM enhances drug delivery in bEND.3 cells by modulating membrane properties via ROS production and changes in membrane potential. CAM offers a promising strategy for improving drug delivery to the brain, with potential applications in brain-targeted therapies. Full article

In pursuit of overcoming Fenton oxidation limitations in wastewater treatment, an introduction of a heterogeneous photocatalyst was developed. In this regard, the current work introduces ZnO nanocrystals that were successfully prepared via a thermal decomposition technique and then capped with oleic acid (OA). The synthesized ZnO-OA and the pristine ZnO were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FE-SEM). Then, the study introduces the application of such materials in advanced oxidation processes, i.e., a Fenton reaction to treat dye-containing wastewater. Synthetic wastewater that was prepared using Reactive Blue 4 (RB4) was used as a simulated textile wastewater effluent. Fenton’s oxidation was applied, and the system parameters were assessed using the modified Fenton’s system. The synthesized samples of ZnO were characterized by a recognized wurtzite hexagonal structure. The surface modification of ZnO with oleic acid (OA) resulted in an increase in crystallite size, lattice parameters, and cell volume. These modifications were linked to the efficient capping of ZnO nanoparticles by OA, which further improved the dispersion of the nanoparticles, as demonstrated through SEM imaging. The optimum conditions of ZnO- and ZnO-OA-synthesized modified Fenton composites showed 400 mg/L and 40 mg/L for H₂O₂ and the catalyst, respectively, at pH 3.0, and within 90 min under UV irradiation the maximal dye oxidation reached 93%. The catalytic performance at its optimal circumstances was in accordance with a pseudo-second-order kinetics model for both ZnO-OA- and the pristine ZnO-based Fenton’s systems. The thermodynamic parameters, including the enthalpy (ΔH′), the entropy (ΔS′), and Gibbs free energy (ΔG′) of activations, were also checked, and their values settled that both ZnO and ZnO-OA Fenton systems are non-spontaneous in nature. Furthermore, the reaction signified for processing at a low energy barrier condition (10.38 and 31.38 kJ/mol for ZnO-OA- and the pristine ZnO-based Fenton reactions, respectively). Full article

Developing novel sorbents for effective removal of heavy metals and organic dyes from industrial wastewater remains a central theme for water research. We modified hydrochar derived from the hydrothermal carbonization of wheat straw at 180 °C with 3-Aminopropyl triethoxysilane (APTES) to enhance its versatile adsorption of Pb(II), Cu(II), methylene blue (MB), and reactive red (Red). Pristine and modified hydrochar (HyC and APTES-HyC) were characterized and tested for sorption performance. Characterization results revealed an enriched presence of N-functional groups, mainly -NH₂ and C-N, on APTES-HyC, in addition to an increased specific surface area from 1.14 m²/g (HyC) to 4.51 m²/g. APTES-HyC exhibited a faster adsorption rate than HyC, reaching equilibrium approximately 4 h after initiation. The Langmuir adsorption capacities of APTES-HyC were 49.6, 14.8, 31.7, and 18.3 mg/g for Pb(II), Cu(II), MB, and Red, respectively, about 8.5, 5.0, 1.3, and 9.5 times higher than for HyC. The enhanced adsorption performance of APTES-HyC is attributed to the increased N-functional groups, which facilitated adsorption mechanisms specific to the pollutant of concern such as formation of frustrated Lewis pairs and cation–π interactions for metal ions and π–π interactions and hydrogen bond for dyes. This study offers a novel and facile approach to the synthesis of N-doped carbon materials for practical applications. Full article

By combining measurements of photocatalysis under solar irradiation with measurements of total organic carbon, we have compared the performance of two TiO₂-based photocatalysts in the photodegradation of the dye Reactive Blue 49 (RB49). TiO₂-P25 and TiO₂-UV100 commercial photocatalysts were tested within a concentration ranging from 0.5 to 4 g/L. The dye solution concentration was varied from 10 to 50 mg/L and its pH was increased from 3 to 9. Extensive characterization of the photocatalysts was performed using Fourier-transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. TiO₂-UV100 proved to be more active in adsorbing RB49 dye than TiO₂-P25. At low dye concentrations, the adsorption equilibrium is reached in 15 min. This time increases to 1 h at higher concentrations. The photocatalytic degradation of aqueous RB49 under sunlight was monitored by UV-Vis spectrophotometry. The apparent rate constant of dye photodegradation with TiO₂-UV100 is twice that of TiO₂-P25. The total organic carbon (TOC) analysis showed a removal of around 98% with TiO₂-UV100 and only 85% with TiO₂-P25 after 3 h of solar irradiation. Over five photocatalytic cycles of 3 h, TiO₂-UV100 maintained a more stable and higher efficient photocatalytic performance. All our results converge toward a better photocatalytic performance of TiO₂-UV100 for the photodegradation of RB49 dye and indicate that the most decisive factor is its greater capacity to adsorb the pollutant. Full article

To fully harness the potential of laccase in the efficient decolorization and detoxification of single and mixed dyes with diverse chemical structures, we carried out a systematic study on the decolorization and detoxification of single and mixed dyes using a crude laccase preparation obtained from a white-rot fungus strain, Pleurotus eryngii. The crude laccase preparation showed efficient decolorization of azo, anthraquinone, triphenylmethane, and indigo dyes, and the reaction rate constants followed the order Remazol Brilliant Blue R > Bromophenol blue > Indigo carmine > New Coccine > Reactive Blue 4 > Reactive Black 5 > Acid Orange 7 > Methyl green. This laccase preparation exhibited notable tolerance to SO₄²⁻ salts such as MnSO₄, MgSO₄, ZnSO₄, Na₂SO₄, K₂SO₄, and CdSO₄ during the decolorization of various types of dyes, but was significantly inhibited by Cl⁻ salts. Additionally, this laccase preparation demonstrated strong tolerance to some organic solvents such as glycerol, ethylene glycol, propanediol, and butanediol. The crude laccase preparation demonstrated the efficient decolorization of dye mixtures, including azo + azo, azo + anthraquinone, azo + triphenylmethane, anthraquinone + indigo, anthraquinone + triphenylmethane, and indigo + triphenylmethane dyes. The decolorization kinetics of mixed dyes provided preliminary insight into the interactions between dyes in the decolorization process of mixed dyes, and the underlying reasons and mechanisms were discussed. Importantly, the crude laccase from Pleurotus eryngii showed efficient repeated-batch decolorization of single-, two-, and four-dye mixtures. This crude laccase demonstrated high stability and reusability in repeated-batch decolorization. Furthermore, this crude laccase was efficient in the detoxification of different types of single dyes and mixed dyes containing different types of dyes, and the phytotoxicity of decolorized dyes (single and mixed dyes) was significantly reduced. The crude laccase efficiently eliminated phytotoxicity associated with single and mixed dyes. Consequently, the crude laccase from Pleurotus eryngii offers significant potential for practical applications in the efficient decolorization and management of single and mixed dye pollutants with different chemical structures. Full article

Wastewater is one of the major concerns for agriculture, and the composition of wastewater depends on its origin. Generally, industrial wastewater consists of azo dyes and heavy metals that contaminate the food chain. In this study, nickel oxide nanoparticles (NiO-NPs) were biosynthesized from Shewnella spp. and characterized by UV–visible spectroscopy (UV–vis), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Azo dye decolorization indicated that NiO-NPs decolorize methylene blue (MB) (82.36%), Congo red (CR) (93.57%), malachite green (MCG) (91.05%), reactive black 5(RB5) (55.17%), reactive red-II(RR-II) (55.45%), and direct blue-I(DB-I) (59.94%) at a dye concentration of 25 mg L⁻¹ after 4 h of sunlight exposure. Additionally, the rate of decolorization was also examined for a 50 mg L⁻¹ concentration of dye. In order to investigate the photocatalytic potential of NiO-NPs, different dyes were also subjected to static and shaking conditions for dye decolorization. The treatment of industrial wastewater with NiO-NPs showed a significant reduction in pH from 8.5 to 6.1, EC (48.38%), chemical oxygen demand (49.24%), total dissolved solids (67.05%), sulfates (52.5%), and phosphates (49.49%). The results of this study indicated that biosynthesized NiO-NPs are an attractive choice for azo dye degradation and industrial wastewater treatment, and they can help save the depleted natural resources of water for agricultural purposes. Full article

In the framework of wastewater treatment plants, sewage sludge can be directed to biochar production, which when coupled with an external iron source has the potential to be used as a carbon–iron composite material for treating various organic pollutants in advanced oxidation processes. In this research, “green” synthesized nano zero-valent iron (nZVI) supported on sewage sludge-based biochar (BC)–nZVI-BC was used in the Fenton process for the degradation of the recalcitrant organic molecule. In this way, the circular economy principles were supported within wastewater treatment with immediate loop closing; unlike previous papers, where only the water treatment was assessed, the authors proposed a new approach to wastewater treatment, combining solutions for both water and sludge. The following phases were implemented: synthesis and characterization of nano zero-valent iron supported on sewage sludge-based biochar (nZVI-BC); optimization of organic pollutant removal (Reactive Blue 4 as the model pollutant) by nZVI-BC in the Fenton process, using a Definitive Screening Design (DSD) model; reuse of the obtained Fenton sludge, as an additional catalytic material, under previously optimized conditions; and assessment of the exhausted Fenton sludge’s ability to be used as a source of nutrients. nZVI-BC was used in the Fenton treatment for the degradation of Reactive Blue 4—a model substance containing a complex and stable anthraquinone structure. The DSD model proposes a high dye-removal efficiency of 95.02% under the following optimal conditions: [RB4] = 50 mg/L, [nZVI] = 200 mg/L, [H₂O₂] = 10 mM. pH correction was not performed (pH = 3.2). Afterwards, the remaining Fenton sludge, which was thermally treated (named FS_treated), was applied as a heterogeneous catalyst under the same optimal conditions with a near-complete organic molecule degradation (99.56% ± 0.15). It could be clearly noticed that the cumulative amount of released nutrients significantly increased with the number of leaching experiments. The highest cumulative amounts of released K, Ca, Mg, Na, and P were therefore observed at the fifth leaching cycle (6.40, 1.66, 1.12, 0.62, 0.48 and 58.2 mg/g, respectively). According to the nutrient release and toxic metal content, FS_treated proved to be viable for agricultural applications; these findings illustrated that the “green” synthesis of nZVI-BC not only provides innovative and efficient Fenton catalysts, but also constitutes a novel approach for the utilization of sewage sludge, supporting overall process sustainability. Full article

The objectives of the present study were to develop an environmentally friendly, low-price, easy, and fast method for developing antipathogenic (antibacterial, antifungal, and antiviral) cuprous-oxide-coated multifunctional fabrics. The fabrics were first sensitized with citric acid, and then Cu²O particles were formed using the Fehling solution method. The cuprous oxide particles were then applied to the cotton fabrics. To create the Cu²O particles, three different kinds of reducing agents with varying concentrations were used. SEM, dynamic light scattering, FTIR, EDS, and XRD were used to examine the surface morphologies and metal presences. In the second step, a reactive antibacterial dye was made (by reacting Reactive Blue 4 with triclosan). The molecular structure of the modified dye was confirmed with FTIR. The resultant antibacterial dye was applied on the copper-treated cotton fabrics in accordance with the exhaust dyeing protocol. The dyed fabrics were characterized through the colorimetric data (L*, a*, b*, C, H, and K/S), levelness of dye, fastness properties as well as exhaustion and fixation rates. Cuprous-oxide-coated fabrics were tested for antipathogenic activity using quantitative and qualitative measurement results. The fabrics treated with cuprous oxide particles reduced with sodium hydrosulfite at 1 g/L seemed to have the highest antipathogenic effect. Moreover, the versatility of the hygienically developed bioactive fabrics in terms of their comfort properties such as air permeability and stiffness were investigated. Finally, the coating’s durability was confirmed by evaluating its antibacterial properties and performing an SEM analysis after laundry. Full article

For the photocatalytic removal of the Reactive Blue 4 dye from an aqueous stream, new polyaniline/multi walled carbon nanotube nanocomposites (PANI-MWCNTs) were applied as a promising photocatalyst. The PANI-MWCNT nanocomposites were fabricated by aniline oxidation in the presence of MWCNTs using the typical direct oxidation polymerization route. The morphology, the Fourier transform infrared (FTIR) spectra and the UV-Vis absorbance spectra of the fabricated nanocomposites were studied and the attained data confirmed the good interaction between the MWCNTs and PANI matrix. The PANI-MWCNTs nanocomposites were varied according to the wt%, the MWCNTs, which ranged from 0–10 wt% and the corresponding resultant samples are labeled as P-0, P-3, P-5, P-5, P-7 and P-10, respectively. Such composites showed the high potential for the removal of the Reactive Blue 4 dye containing pollutants from wastewater. The starting concentration of the dye pollutants was halved during the first 5 min of UV illumination. The oxidation technique of Reactive Blue 4 over the prepared nanocomposites were processed in a different way and the highest catalytic activity corresponded to P-7. The process reached the complete dye removal in low concentrations of contaminants. The kinetics of the removal followed the pseudo-second order regime which possesses high correlation coefficients with the k₂ in the range of 0.0036–0.1115 L.mg⁻¹.min⁻¹ for the Reactive Blue 4 oxidation. In this regard, the combination of the PANI and MWCNTs showed a superior novel photocatalytic activity in the oxidation of commercial textile dying wastewater, namely Reactive Blue 4. This study is the starting point for future applications on an industrial scale since the successful performances of the PANI-MWCNT on commercial dye oxidation. Full article

Biochars (BCs) are very versatile adsorbents, mainly, in the effectiveness of adsorption of organic and inorganic compounds in aqueous solutions. Here, the sugarcane biomass (SCB) was used to produce biochar at different carbonization times: 1, 2, 3, 4, and 5 h, denominated as BC1, BC2, BC3, BC4, and BC5, respectively. The superficial reactivity was studied with adsorption equilibrium experiments and kinetics models; Methylene Blue (MB) was used as adsorbate at different pH values, concentrations, and temperatures. In summary, the carbonization time provides the increase of superficial area, with exception of BC4, which decreased. Equilibrium studies showed inflection points and fluctuations with different initial dye concentration and temperature; SCB showed the best adsorption capacity compared to the BCs at the three temperatures tested, varying with the increase of MB concentration, suggesting the dependence of these two main factors on the adsorption process. The proposed adsorption mechanism suggests the major influence of Coulomb interactions, H-bonding, and π-interactions on the adsorption of MB onto adsorbents, evidencing that the adsorption is led by physical adsorption. Therefore, the results led to the use of the SCB without carbonization at 200 °C, saving energy and more adsorbent mass, considering that the carbonization influences weight loss. This study has provided insights of the use of SCB in MB dye adsorption as a low-cost and eco-friendly adsorbent. Full article

Photocatalytic degradation is one of the environmentally friendly methods used in treating dye wastewater. In this study, a series of MXene/g-C₃N₄ heterostructure photocatalysts with different loading amounts of MXene (1, 4, 8, and 12 wt.%) were successfully synthesized via the wet impregnation method and their photocatalytic activity was evaluated via the degradation of methylene blue under visible-light irradiation. As such, the 1 wt.% MXene/g-C₃N₄ heterostructure photocatalyst achieved a high degradation of methylene blue compared to the pure g-C₃N₄ under visible-light illumination of 180 min. This significant improvement was attributed to the intimate interfacial contact, evidently from the FESEM analysis, which allows the smooth photocharge carriers to transport between g-C₃N₄ and MXene. Additionally, the larger BET surface area demonstrated by the 1 wt.% MXene/g-C₃N₄ heterostructure allowed this sample to have higher adsorption of dye molecules and provided a higher number of reactive sites, which was beneficial for the enhancement of the photocatalytic activity. Nevertheless, it was found that the excessive loading of MXene can substantially impede photocatalytic activity. This was attributed to the decrease in the active sites, as well as the weakened crystallinity of the MXene/g-C₃N₄ heterostructure photocatalyst, evident from the FTIR and XRD analysis. All in all, this study has shown the potential of the MXene/g-C₃N₄ photocatalyst as a promising photocatalyst for highly efficient wastewater treatment applications. Full article

The titanium dioxide-silicon dioxide (TiO₂-SiO₂) nanocomposite used for the study was synthesized using a sol-gel method followed by UV-treatment. The physicochemical properties of the synthesized catalyst, TiO₂-SiO₂ were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS) and photoluminescence (PL). The photocatalytic degradation of methylene blue (MB) dye was evaluated in the presence of TiO₂-SiO₂ and reactive chlorine species (RCS) under experimental conditions. By comparing the important reaction processes in the study, including photocatalysis, chlorination and photocatalytic chlorination, it was found out that the process of photocatalytic chlorination had the highest photodegradation efficiency (95% at 60 min) of the MB under optimum reaction conditions (MB = 6 mg L⁻¹, catalyst = 0.1 g and pH = 4). The enhanced removal of MB from the aqueous medium was identified because of the synergy between chlorination and photocatalysis activated in the presence of TiO₂-SiO₂. The mechanism of the photocatalytic chlorination process was scrutinized in the presence of various RCS and reactive oxygen species (ROS) scavengers. Based on the experimental data attained, Na₂S₂O₃ exhibited the highest inhibitory effect on the degradation efficiency of MB, indicating that the RCS is the main contributor to visible light-induced photodegradation of MB. Full article

Biobased carbon materials (BBC) obtained from Norway spruce (Picea abies Karst.) bark was produced by single-step chemical activation with ZnCl₂ or KOH, and pyrolysis at 800 °C for one hour. The chemical activation reagent had a significant impact on the properties of the BBCs. KOH-biobased carbon material (KOH-BBC) had a higher specific surface area (S_BET), equal to 1067 m² g⁻¹, larger pore volume (0.558 cm³ g⁻¹), more mesopores, and a more hydrophilic surface than ZnCl₂-BBC. However, the carbon yield for KOH-BBC was 63% lower than for ZnCl₂-BBC. Batch adsorption experiments were performed to evaluate the ability of the two BBCs to remove two dyes, reactive orange 16 (RO-16) and reactive blue 4 (RB-4), and treat synthetic effluents. The general order model was most suitable for modeling the adsorption kinetics of both dyes and BBCs. The equilibrium parameters at 22 °C were calculated using the Liu model. Upon adsorption of RO-16, Q_max was 90.1 mg g⁻¹ for ZnCl₂-BBC and 354.8 mg g⁻¹ for KOH-BBC. With RB-4, Qmax was 332.9 mg g⁻¹ for ZnCl₂-BBC and 582.5 mg g⁻¹ for KOH-BBC. Based on characterization and experimental data, it was suggested that electrostatic interactions and hydrogen bonds between BBCs and RO-16 and RB-4 dyes played the most crucial role in the adsorption process. The biobased carbon materials showed high efficiency for removing RO-16 and RB-4, comparable to the best examples from the literature. Additionally, both the KOH- and ZnCl₂-BBC showed a high ability to purify two synthetic effluents, but the KOH-BBC was superior. Full article

Tamoxifen is the most widely used selective modulator of estrogen receptors (SERM) and the first strategy as coadjuvant therapy for the treatment of estrogen-receptor (ER) positive breast cancer worldwide. In spite of such success, tamoxifen is not devoid of undesirable effects, the most life-threatening reported so far affecting uterine tissues. Indeed, tamoxifen treatment is discouraged in women under risk of uterine cancers. Recent molecular design efforts have endeavoured the development of tamoxifen derivatives with antiestrogen properties but lacking agonistic uterine tropism. One of this is FLTX2, formed by the covalent binding of tamoxifen as ER binding core, 7-nitrobenzofurazan (NBD) as the florescent dye, and Rose Bengal (RB) as source for reactive oxygen species. Our analyses demonstrate (1) FLTX2 is endowed with similar antiestrogen potency as tamoxifen and its predecessor FLTX1, (2) shows a strong absorption in the blue spectral range, associated to the NBD moiety, which efficiently transfers the excitation energy to RB through intramolecular FRET mechanism, (3) generates superoxide anions in a concentration- and irradiation time-dependent process, and (4) Induces concentration- and time-dependent MCF7 apoptotic cell death. These properties make FLTX2 a very promising candidate to lead a novel generation of SERMs with the endogenous capacity to promote breast tumour cell death in situ by photosensitization. Full article

Appropriately disposing of and reusing waste is a major step in promoting environmentally sustainable development. Following the rise in environmental awareness, agricultural waste has been applied as a reusable organic resource and as a cost-efficient material for preparing hydrogel adsorbents. The present study combined rice bran with sodium alginate and chitosan to prepare two new types of hydrogel beads. The beads were then modified using simple methods, and their material characteristics were analyzed using a Fourier transform infrared spectroscope, a scanning electron microscope, and thermogravimetric analysis. Specifically, the effects of pH, adsorbent dosage, adsorption time, and adsorption temperature on the performance of the hydrogel beads in the adsorption of dyes with various properties were examined. The results revealed that the optimal conditions for the rice bran/alginate hydrogel beads to adsorb crystal violet were pH 5, a dosage of 30 mg, at 30 °C, for 6 h of adsorption; furthermore, the kinetic and isothermal adsorption data were found to be consistent with the pseudo-second-order model and the Freundlich isotherm model, respectively. The optimal conditions for the rice bran/chitosan hydrogel beads to adsorb reactive blue 4 were pH 3, a dosage of 40 mg, at 50 °C, for 7 h of adsorption, and the kinetic and isothermal adsorption data were consistent with the pseudo-first-order model and the Langmuir isotherm model, respectively. This study applied natural polymers and agricultural waste to prepare cost-efficient and environmentally friendly adsorbents, which satisfy today’s environmental protection trends and economic values because of their low environmental impact and favorable adsorptive and regenerative properties. They can be prepared without high-temperature and high-pressure processing, and can be recycled through the separation of water bodies using simple filter methods, thus substantially reducing energy and monetary costs. Full article