Search Results (92)

Surfactants are chemical compounds present in a large number of products that people use on a daily basis, starting with detergents for washing clothes, dishes, personal hygiene products, etc. Some products also contain certain heavy metals. Their uses cause heavy contamination of wastewater that must be purified before discharge into receivers. Given that some types of surfactants are very persistent and heavy metals are non-biodegradable and toxic even in small concentrations, the purification process requires a complex approach and a combination of different methods. Bioremediation, as an environmentally acceptable and economically clean technology, has great potential. It is based on the use of indigenous microorganisms that have developed different mechanisms for breaking down and removing or detoxifying a large number of pollutants and are excellent candidates for bioremediation of wastewater. Bacteria can degrade surfactants as sole carbon sources and exhibit tolerance to various heavy metals. This paper summarizes the most significant results, highlighting the potential of bacteria for the biodegradation of surfactants and heavy metals, with the aim of drawing attention to their insufficient practical application in wastewater treatment. Bioreactors and microbial fuel cells are described as currently relevant strategies for bioremediation. Full article

Carbon dioxide (CO₂) has been widely applied in gas flooding for reservoir development due to its remarkable oil recovery potential. However, because its viscosity is lower than that of water and most crude oils, severe channeling often occurs during the flooding process, resulting in a significant reduction in the sweep efficiency. To address this issue, foam flooding has attracted considerable attention as an effective method for controlling CO₂ mobility. In this study, a compound foam system was developed with alpha-olefin sulfonate (AOS) as the primary foaming agent, alcohol ethoxylate (AEO) and cetyltrimethylammonium bromide (CTAB) as co-surfactants, and partially hydrolyzed polyacrylamide (HPAM) as the stabilizer. The optimal system was screened through evaluations of comprehensive foam index, salt tolerance, oil resistance, and shear resistance. Results indicate that the AOS+AEO formulation exhibits superior foaming ability, salt tolerance, and foam stability compared with the AOS+CTAB system, with the best performance achieved at a mass ratio of 2:1 (AOS:AEO), balancing both adaptability and economic feasibility. A heterogeneous reservoir model was constructed using parallel core flooding to investigate the displacement performance and blocking capability of the system. Nuclear magnetic resonance (NMR) imaging was employed to monitor in situ oil phase migration and clarify the recovery mechanisms. Experimental results show that the compound foam system demonstrates excellent conformance control performance, achieving a blocking efficiency of 84.5% and improving the overall oil recovery by 4.6%. NMR imaging further reveals that the system effectively mobilizes low-permeability zones, with T₂ spectrum analysis indicating a 4.5% incremental recovery in low-permeability layers. Moreover, in reservoirs with larger permeability ratio, the system exhibits enhanced blocking efficiency (up to 86.5%), though the incremental recovery is not strictly proportional to the blocking effect. Compared with previous AOS-based CO₂ foam studies that primarily relied on pressure drop and effluent analyses, this work introduces NMR imaging and T₂ spectrum diagnostics to directly visualize pore-scale fluid redistribution and quantify sweep efficiency within heterogeneous cores. The NMR data provide mechanistic evidence that the enhanced recovery originates from selective foam propagation and the mobilization of residual oil in low-permeability channels, rather than merely from increased flow resistance. This integration of advanced pore-scale imaging with macroscopic displacement analysis represents a mechanistic advancement over conventional CO₂ foam evaluations, offering new insights into the conformance control behavior of AOS-based foam systems in heterogeneous reservoirs. Full article

Cefuroxime sodium (CEF) is a second-generation cephalosporin that remains unstable in an aqueous environment. The answer to this low stability may be self-emulsifying oils, which are isotropic mixtures of oil and surfactants, in which the stability of CEF has already been proven. Self-emulsifying oils are well known for their ability to enhance the solubility and bioavailability of lipophilic drugs. This research presents a preliminary in vivo study of an innovative approach to develop eye drops in the form of a self-emulsifying oil (SEO) containing suspended water-labile antibiotic cefuroxime sodium. Such a concept has never been explored before. Upon contact with tear fluid, the preparation rapidly forms an emulsion, allowing for the rapid dissolution of the antibiotic. The aim of the study was to assess the tolerability of such eye drops. CEF (5% w/w) was suspended in SEO carriers, prepared by dissolving surfactants (Tween 20; 5% w/w) in Miglyol. The in vivo evaluation was conducted on rabbits after two once-a-day applications of the eye drops. The study demonstrated the safety of both the SEO-placebo and the SEO containing suspended CEF. The formulations did not affect the appearance of the cornea and iris. During the observations, only changes in the conjunctiva of the eye were noted, which manifested as conjunctival hyperemia. The result of the Draize test was an average of 3.3 points out of 110 possible points, which classifies the CEF-SEO suspension as minimally irritating. Full article

Fungal laccases oxidize a wide range of substrates with a diverse spectrum of subsequent non-specific free radical reactions, leading to the production of unwanted byproducts. This work describes a unique recombinant alkaliphilic laccase from Paramyrothecium roridum VKM F-3565 capable of performing specific oligomerization of phenylpropanoids (precursors of natural lignin and lignans) in a neutral environment, thus preventing the reverse reaction of depolymerization which occurs in an acidic environment. The recombinant alkaliphilic laccase from P. roridum VKM F-3565 with a specific enzyme activity of about 154.0 U/mg (in the reaction with 1 mM ABTS) was obtained using a Komagataella phaffii transformant with a yield of 20 ± 1.5 mg/L. The recombinant laccase had an increased degree of N-glycosylation (MW = 97 kDa), higher pH optimum in reaction with phenylpropanoids and a decreased temperature optimum, compared to the wild-type laccase. The enzyme exhibited great resistance to surfactants and the EDTA in the neutral conditions rather than the acidic ones, whereas its tolerance to mono- and divalent-metal ions was high at acidic conditions. This work demonstrates the important role of N-glycosylation of the alkaliphilic laccase of P. roridum VKM F-3565 in its functional activity. The presence of pH-dependent reactions makes the studied laccase attractive for the phenylpropanoid oligomerization with the production of novel oligomeric phenylpropanoid derivatives for industrial and pharmacological purposes. Full article

This work aims to design versatile hybrids fabricated by poly(hydroxypropyl methacrylate-co-glycidyl methacrylate) gels loaded with pristine montmorillonite, P(HPMA-co-GMA)/Mmt, by varying the clay content. Insights into design of epoxy-functional hybrids were provided by combining in situ copolymerization reactions with solution mixing to evaluate the effect of aluminosilicate addition on structure–property changes in (alkyl)methacrylate-based gels. Comprehensive analyses were conducted regarding the composition and structural properties of hybrids in the presence of Mmt. The hybrids exhibited excellent swelling, salt surfactant tolerance, and pH sensitivity depending on the composition. The higher the Mmt concentration, the lower the swelling ratio; however, the compressive moduli did not change monotonically with increasing Mmt from 0.80 to 2.20% (w/v). Dye adsorption revealed the effects of variables (dye type, pH, contact time, concentration) on adsorptive properties of hybrids towards cationic methylene blue (MB) and anionic sunset yellow, allura red, blue brilliant, carmoisine, and tartrazine dyes. Adsorption kinetics of MB obeyed pseudo-second-order model, and the maximum dye adsorption capacity for hybrids increased from 5.01 mg g⁻¹ to 16.42 mg g⁻¹, while adsorption isotherms were defined by the Freundlich model. The proposed hybrids have emerged as alternative materials that enable multiple uses of same adsorbent for the removal of different types of pollutants. Full article

Keratinous biomass, such as feathers, wool, and hair, poses environmental challenges due to its insoluble and recalcitrant nature. In this study, we identified, purified and comprehensively characterized a previously uncharacterized extracellular alkaline keratinase, KerFJ, secreted by Bacillus sp. FJ-3-16, with broad industrial application potential. KerFJ was produced at high yield (1800 U/mL) in an optimized cost-effective medium and purified to homogeneity using ion-exchange chromatography. The enzyme exhibited optimal activity at pH 9.5 and 55 °C, with remarkable alkaline and thermal stability, and high tolerance to surfactants, oxidants, and metal ions. Sequence analysis revealed that KerFJ is a member of the serine peptidase S8 family, with a molecular weight of ~27.5 kDa. It efficiently degraded native keratin substrates, achieving 70.3 ± 2.1% feather, 39.7 ± 1.8% wool, and 15.4 ± 1.2% hair degradation, and the resulting feather hydrolysates exhibited strong antioxidant activities. KerFJ also demonstrated excellent compatibility with commercial detergents and enabled effective stain removal from fabrics without damage. Moreover, both laboratory- and pilot-scale trials showed that KerFJ facilitated non-destructive dehairing of sheep, donkey, and pig skins while preserving collagen integrity. These results highlight KerFJ as a robust and multifunctional biocatalyst suitable for keratin waste valorization, eco-friendly leather processing, and detergent formulations. Full article

Heavy-oil reservoirs exhibit a high water–oil mobility ratio. During cyclic steam stimulation or water flooding in the later stages, severe fingering occurs, making it difficult to produce the remaining oil. Chemical flooding methods such as polymer flooding, surfactant–polymer flooding, weak gel flooding, and gel flooding have achieved significant enhanced oil recovery (EOR) effects in the development of high-water-cut oilfields in China. However, the reservoir applicability conditions for each chemical flooding method differ. How to quickly select the appropriate chemical flooding method based on reservoir conditions remains a challenge. This paper uses the basic parameters of a heavy-oil reservoir in Shengli Oilfield as a reference and establishes numerical simulation models for different chemical flooding methods. Then, using the permeability variation coefficient as an indicator to evaluate reservoir heterogeneity, the suitable permeability variation coefficient ranges for different chemical flooding methods are obtained and used as the first-level decision method. Subsequently, based on the differences in temperature and salt tolerance of each chemical flooding method, the applicable ranges for different chemical flooding methods are determined and used as the second-level decision method. Through this two-level decision-making process, the suitable chemical flooding development method for a target reservoir can be rapidly identified, providing support for the efficient development of heavy-oil reservoirs using chemical flooding. The findings are based on a typical heavy-oil reservoir model from Shengli Oilfield; the specific thresholds presented should be calibrated accordingly when applied to reservoirs with different characteristics. Full article

The effective and rapid separation of oil–water emulsions at room temperature, particularly under harsh environmental conditions like acid–base fluctuations, high salinity, and the coexistence of surfactants, remains a significant challenge in oily wastewater treatment. To address this, a novel amphiphilic demulsifier, MOF-74@SiO₂-GPTMS grafted ANP (MSG-ANP), was synthesized by first modifying MOF-74@SiO₂ (MS) with γ-glycidoxypropyltrimethoxysilane (GPTMS) to create epoxy-functionalized MSG particles, followed by grafting the non-ionic polyether C₁₂–C₁₄ aliphatic polyethylene oxide polyoxypropylene (ANP) onto MSG. Bottle tests demonstrated that MSG-ANP achieved a high demulsification efficiency of 93% within 15 min for oil-in-water emulsions at room temperature. It exhibited excellent environmental tolerance, maintaining efficiencies of 89% at pH 3.0, 82% at pH 11.0, and 95% under high salinity (50,000 mg/L, pH 6.8). Furthermore, MSG-ANP effectively treated surfactant-stabilized emulsions, exceeding 96% efficiency against both cetyltrimethylammonium bromide and sodium dodecyl sulfate after 30 min, outperforming commercial demulsifiers SP-169 and AR-331 by factors of 1.2 and 1.6, respectively. This superior performance stems from synergistic hydrogen bonding (via hydroxyl, ether, ester, Fe-O, and Si-O groups) destabilizing the interfacial film and electrostatic neutralization of coalescing charged droplets. Consequently, MSG-ANP presents a promising solution for rapid, room-temperature demulsification across a wide pH range and under high-salinity conditions. Full article

Sunflower (Helianthus annuus L.) is an important oilseed crop in Northwest China, exhibiting resistance to salt and drought. Mining its excellent tolerance genes can be used for breeding. However, the current platforms for identifying gene function in sunflower is inadequate. The transient transformation system, which can rapidly validate gene function, shows promising prospects in research. In this study, we established an efficient transient expression transformation system for sunflower using three methods: Agrobacterium-mediated infiltration, injection, and ultrasonic-vacuum. The detailed procedures were as follows: Agrobacterium GV3101 carrying a GUS reporter gene on the pBI121 vector with an OD₆₀₀ of 0.8 as the bacterial suspension and 0.02% Silwet L-77 as the surfactant were utilized in all three approaches. For the infiltration method, seedlings grown hydroponically for 3 days were immersed in a bacterial suspension containing 0.02% Silwet L-77 for 2 h; for the injection method, the same solution was injected into the cotyledons of seedlings grown in soil for 4 to 6 days. Subsequently, the seedlings were cultured in the dark at room temperature for three days; for the ultrasonic-vacuum method, seedlings cultured in Petri dishes for 3 days were first subjected to ultrasonication at 40 kHz for 1 min, followed by vacuum infiltration at 0.05 kPa for 5–10 min. Agrobacterium-mediated transient transformation efficiency achieved by the three methods exceeded 90%, with gene expression being sustained for at least 6 days. Next, we employed the infiltration-based sunflower transient transformation technology with the Arabidopsis stable transformation platform to confirm salt and drought stress tolerance of candidate gene HaNAC76 from sunflower responding to various abiotic stresses. Altogether, this study successfully established an Agrobacterium-mediated transient transformation system for sunflower using these three methods, which can rapidly identify gene function and explore the molecular mechanisms underlying sunflower’s resistance traits. Full article

The development of eco-friendly surfactants is pivotal for enhanced oil recovery (EOR). In this study, a novel lignin-derived zwitterionic surfactant (DMS) was synthesized through a two-step chemical process involving esterification and free radical polymerization, utilizing renewable alkali lignin, maleic anhydride, dimethylamino propyl methacrylamide (DMAPMA), and sulfobetaine methacrylate (SBMA) as precursors. Comprehensive characterization via ¹H NMR, FTIR, and XPS validated the successful integration of amphiphilic functionalities. Hydrophilic–lipophilic balance (HLB) analysis showed a strong tendency to form stable oil-in-water (O/W) emulsions. The experimental results showed a remarkable 91.6% viscosity reduction in Xinjiang heavy crude oil emulsions at an optimum dosage of 1000 mg/L. Notably, DMS retained an 84.8% viscosity reduction efficiency under hypersaline conditions (total dissolved solids, TDS = 200,460 mg/L), demonstrating exceptional salt tolerance. Mechanistic insights derived from zeta potential measurements and molecular dynamics simulations revealed dual functionalities: interfacial modification by DMS-induced O/W phase inversion and electrostatic repulsion (zeta potential: −30.89 mV) stabilized the emulsion while disrupting π–π interactions between asphaltenes and resins, thereby mitigating macromolecular aggregation in the oil phase. As a green, bio-based viscosity suppressor, DMS exhibits significant potential for heavy oil recovery in high-salinity reservoirs, addressing the persistent challenge of salinity-induced inefficacy in conventional chemical solutions and offering a sustainable pathway for enhanced oil recovery. Full article

Improving the aqueous solubility of poorly soluble pharmaceuticals is essential for accurate pharmacotoxicological testing, but the biological safety of solubilizers and hydrotropic agents used for this purpose requires careful evaluation. This study assessed the acute toxicity, physiological parameters (heart rate, claw and appendage movement), behavioral responses (swimming speed), and embryotoxicity of 15 commonly used solubilizers and hydrotropes using Daphnia magna as a biological model. Compounds included surfactants (polysorbate 20 (Tween 20), polysorbate 80 (Tween 80), sodium lauryl sulfate (SLS)), sulfonated hydrotropes (sodium xylene sulfonate (SXS), sodium benzenesulfonate (SBS), sodium p-toluenesulfonate (PTS), sodium 1,3-benzenedisulfonate (SBDS)), and solubilizing solvents (dimethyl sulfoxide (DMSO), glycerol (GLY), propylene glycol (PDO), dimethylformamide (DMF), N,N’-Dimethylbenzamide (DMBA), N,N-Diethylnicotinamide (DENA), N,N-Dimethylurea (DMU), urea). Acute lethality was evaluated across concentration ranges appropriate to each compound group (e.g., 0.0005–0.125% for surfactants; up to 5% for less toxic solvents). Surfactants exhibited extreme toxicity, with Tween 20 and SLS causing 100% lethality even at 0.0005%, while Tween 80 induced 40–50% lethality at that concentration. In contrast, DMSO, GLY, and PDO showed low acute toxicity, maintaining normal heart rate (202–395 bpm), claw and appendage movement, and swimming speed at ≤1%, though embryotoxicity became evident at higher concentrations (≥1–2%). SXS, SBS, PTS, and SBDS displayed clear dose-dependent toxicity but were generally tolerated up to 0.05%. DMBA, DENA, and DMU caused physiological suppression, including reduced heart rate (e.g., DMBA: 246 bpm vs. control 315 bpm) and impaired mobility. Behavioral assays revealed biphasic effects for DMSO and DMBA, with early stimulation (24 h) followed by inhibition (48 h). Embryotoxicity assays demonstrated significant morphological abnormalities and developmental delays at elevated concentrations, especially for DMSO, GLY, and PDO. Overall, DMSO, GLY, PDO, SXS, and DMF can be safely used at tightly controlled concentrations in Daphnia magna toxicity assays to ensure accurate screening without solvent-induced artifacts. Full article

Linear anionic surfactants (LAS) pose significant stress to microbial denitrification in wastewater treatment. This study investigated the performance and adaptation mechanisms of heterotrophic nitrification-aerobic denitrification (HN-AD) microbial consortia under LAS exposure after short-term (SCM, 2 months) and long-term (LCM, 6 months) acclimation. Results showed a dose-dependent inhibition of total nitrogen (TN) removal, with LCM achieving 97.40% TN removal under 300 mg/L LAS, which was 16.89% higher than SCM. Biochemical assays indicated that LCM exhibited lower reactive oxygen species (ROS) levels, a higher ATP content, and reduced LDH release, suggesting enhanced oxidative stress resistance and membrane stability. EPS secretion also increased in LCM, contributing to environmental tolerance. Metagenomic analysis revealed that long-term acclimation enriched key genera including Pseudomonas, Aeromonas, and Stutzerimonas, which maintained higher expression of denitrification (e.g., nosZ, nirS) and ammonium assimilation genes (glnA, gltB). Although high LAS concentrations reduced overall community diversity and led to convergence between SCM and LCM structures, LCM retained greater functional capacity and stress resistance. These findings underscore the importance of acclimation in sustaining denitrification performance under surfactant pressure and offer valuable insights for engineering robust microbial consortia in complex wastewater environments. Full article

Background: Celastrol (Cela), a phytochemical extracted from Tripterygium wilfordii, has been extensively investigated for its potential anti-inflammatory, anti-psoriatic, antioxidant, neuroprotective, and antineoplastic properties. However, its clinical translation is limited due to poor bioavailability, low solubility, and nonspecific toxicity. This study aimed to develop and evaluate an inhalable Cela-loaded nanoemulsion (NE) formulation to enhance targeted drug delivery and therapeutic efficacy in non-small cell lung cancer (NSCLC). Methods: The NE formulation was optimized using Capmul MCM (25%), Tween 80 (20%), Transcutol HP (5%), and water (50%) as the oil, surfactant, co-surfactant, and aqueous phase, respectively. Physicochemical characterization included globule size, zeta potential, and drug release in simulated lung fluid. In vitro aerosolization performance, cytotoxicity in NSCLC cell lines (A549), scratch and clonogenic assays, and 3D tumor spheroid models were employed to assess therapeutic potential. Results: The NE showed a globule size of 201.4 ± 3.7 nm and a zeta potential of −15.7 ± 0.2 mV. Drug release was sustained, with 20.4 ± 5.5%, 29.1 ± 10%, 64.6 ± 4.1%, and 88.1 ± 5.2% released at 24, 48, 72, and 120 h, respectively. In vitro aerosolization studies indicated a median aerodynamic particle size of 4.8 ± 0.2 μm, confirming its respirability in the lung. Cell culture studies indicated higher toxicity of NE-Cela in NSCLC cells. NE-Cela significantly reduced A549 cell viability, showing a ~6-fold decrease in IC₅₀ (0.2 ± 0.1 μM) compared to Cela alone (1.2 ± 0.2 μM). Migration and clonogenic assays demonstrated reduced cell proliferation, and 3D spheroid models supported its therapeutic activity in tumor-like environments. Conclusions: The inhalable NE-Cela formulation improved Cela’s physicochemical limitations and demonstrated enhanced anti-cancer efficacy in NSCLC models. These findings support its potential as a targeted, well-tolerated therapeutic option for lung cancer treatment. Full article

The aim was to develop a series of handwashing gels containing a standardised extract of the aerial part of Gypsophila trichotoma as well as an essential oil from Xanthium strumarium fruits. The saponins present in the extract are a suitable alternative to synthetic sulphate surfactants and have better skin tolerance, and with the addition of essential oil, a higher antibacterial activity of the gels thus developed is achieved. The elaborated gels were characterised by good spreadability and a pH close to the physiological for healthy skin (pH 5.5), which is a prerequisite for improved skin tolerability. The dynamic rheological studies showed that the extract fraction increase was not associated with gel viscosity change, and it was only a function of the gelling agent concentration. The gels’ foam-forming ability increased with the increasing extract concentrations. The comparative evaluation of the antibacterial activity of elaborated gels vs. plain gel based on coco glucoside against a panel of selected pathogens demonstrated that the newly developed formulations have superior antibacterial effects. Based on the good technological characteristics and the results of antimicrobial testing of the washing gels thus developed, it can be concluded that they are promising candidates as personal hygiene products. Full article

Background: Lipid nanoparticles (LNPs) have proven effective in delivering RNA-based modalities. Rapid approval of the COVID-19 vaccines highlights the promise of LNPs as a delivery platform for nucleic acid-based therapies and vaccines. Nevertheless, improved LNP designs are needed to advance next-generation vaccines and other gene therapies toward greater clinical success. Lipid components and LNP formulation excipients play a central role in biodistribution, immunogenicity, and stability. Therefore, it is important to understand, identify, and assess the appropriate lipid components for developing a safe and effective formulation. Herein, this study focused on developing a novel Polysorbate-80 (PS-80)-based LNP. We hypothesized that substituting conventional linear PEG-lipids with PS-80, a widely used, biocompatible injectable surfactant featuring a branched PEG-like structure, may change the LNPs biodistribution pattern and enhance long-term stability. By leveraging PS-80’s unique structural properties, this study aimed to develop an mRNA-LNP platform with improved extrahepatic delivery and robust freeze/thaw tolerance. Methods: We employed a stepwise optimization to establish both the lipid composition and formulation buffer to yield a stable, high-performing PS-80-based SARS-CoV-2 mRNA-LNP (SC2-PS80 LNP). We compared phosphate- versus tris-based buffers for long-term stability, examined multiple lipid ratios, and evaluated the impact of incorporating PS-80 (a branched PEG-lipid) on in vivo biodistribution. Various analytical assays were performed to assess particle size, encapsulation efficiency, mRNA purity, and in vitro potency of the developed formulation and a humanized mouse model was used to measure its immunogenicity over six months of storage at −80 °C. Results: Replacing the standard 1,2-dimyristoyl-rac-glycero-3-methoxy polyethylene glycol-2000 (PEG-DMG) lipid with PS-80 increased spleen-specific expression of the mRNA-LNPs after intramuscular injection. Formulating in a tris-sucrose-salt (TSS) buffer preserved the LNP’s physicochemical properties and in vitro potency over six months at −80 °C, whereas a conventional PBS-sucrose (PSS) buffer was less protective under frozen conditions. Notably, TSS-based SC2-PS80 LNPs elicited potent humoral immunity in mice, including high anti-spike IgG titers and robust pseudovirus neutralization, comparable to freshly prepared formulations. Conclusions: A PS-80-based mRNA-LNP platform formulated in TSS buffer confers improved extrahepatic delivery, long-term frozen stability, and strong immunogenicity against SARS-CoV-2 following six months. These findings offer a promising pathway for the design of next-generation mRNA vaccines and therapeutics with enhanced stability and clinical potential. Full article