Sodium Dodecyl Sulfate Research Articles

Recovery of alkaline proteinases from fisheries wastes: biochemical characterization and applications.

Fish visceral waste, which is normally discarded, is considered one of the richest sources of proteinases with potential biotechnological applications. For this reason, alkaline proteinases from viscera of Argentine hake Merluccius hubbsi, Brazilian flathead Percophis brasiliensis, Brazilian codling Urophycis brasiliensis, and stripped weakfish Cynoscion guatucupa were characterized. Individuals were caught by a commercial fleet off the coast of the Argentinean Sea. The intestine and pyloric caeca were dissected out and then minced and triturated with distilled water. The proteinase activity of P. brasiliensis extracts was enhanced by all the ions tested (Mn2+, K+, Na+, Ca+2) while the enzymes of the other species were stable in the presence of those ions, retaining more than 60% of their enzymatic activity. Alkaline proteinases of all species showed extreme stability to 5% v/v surfactants at 60 min (Sodium dodecyl sulfate, Triton X-100, Tween 20, Tween 80), and relative stability toward an 6% v/v oxidizing agent (H2O2) and organic solvents 80% (acetone, isopropanol, methanol, ethanol). The enzyme extracts were incubated for 60 min with these compounds. Interestingly, alkaline proteinases from all species were compatible with the commercial detergents (Ala, Skip, and Ace). These results demonstrate that proteinases recovered from a no-cost sample such as fishery residues can be used for industrial applications, such as detergent formulations.

Enhancing Acyclovir Permeability Using SLS Crosslinked β-Cyclodextrin Nanoparticles

Introduction/Objective: Acyclovir, a BCS class III drug (that has high solubility and low permeability) is an antiviral drug used for the treatment of herpes simplex and varicose zoster. To enhance acyclovir's permeability across the intestinal membrane and to improve its bioavailability the β-cyclodextrin (β-CD) nanoparticles of acyclovir were prepared with sodium lauryl sulfate (SLS) as a crosslinking agent. Methods: A phase solubility study was performed with varying ratios of acyclovir to β-CD. Three formulations of acyclovir-loaded β-CD nanoparticles were prepared with drug-β-CD ratios of 1:1, 1:2, and 1:4. The prepared nanoparticle formulations were characterized for FTIR, dynamic light scattering (particle size, polydispersity index, zeta potential) and in vitro permeability studies. Results: Phase solubility study resulted in an "AL type" curve with an association constant (Kc) of 12 M-1 which suggested the formation of a strong complex between acyclovir and β-CD, leading to enhanced solubility of acyclovir with increasing concentrations of β-CD. The FTIR spectrum confirmed the compatibility of acyclovir, β-CD, and SLS in the formulations. Dynamic light scattering analysis demonstrated particle sizes ranging from 152.92 nm to 335.7 nm, with the smallest particles in the 1:4 ratio formulation (152.92 nm), potentially due to higher drug encapsulation. Zeta potential measurements reflected formation of stable nanoparticle suspensions, with the formulation exhibiting a zeta potential of -45.4 mV showcasing optimal stability. In vitro permeation studies revealed that the 1:4 ratio formulation exhibited the highest permeability (84.24 ±1.94 % at the end of 150 min) through the eggshell membrane, implying efficient drug release. This increase in permeability corroborated with its smallest particle size. Conclusion: The study highlights the potential of β-CD nanoparticles (with best performance shown by drug-to-β-CD ratio 1:4) in augmenting acyclovir's delivery, suggesting a promising avenue for improving the drug delivery in viral infections.

Microencapsulated single-component epoxies for self-healing of glass fiber reinforced polymers subjected to low-velocity impacts

This study aimed to investigate the potential of self-healing single-component epoxy microcapsules for improving the impact resistance and durability of glass fiber-reinforced polymer (GFRP) composites. Microcapsules containing a single-component epoxy resin were synthesized using sodium lauryl sulfate and polyvinyl alcohol as stabilizing agents. The microcapsules were characterized, revealing an average size of 3.056 μm. GFRP composites embedded with 10 wt% of the synthesized microcapsules were prepared. The composites were subjected to low-velocity impacts at velocities of 3 m/s, 3.5 m/s, and 4 m/s. Residual flexural properties were evaluated using three-point bending tests. The impact resistance and self-healing efficiency of the GFRP composites showed significant improvement. The flexural after-impact strength exhibited considerable recovery post-impact. A healing efficiency of 61.1% was observed for specimens impacted at a velocity of 3 m/s. Incorporating microcapsules loaded with healing agents transforms GFRP composites into smart materials. The microcapsules act as microscopic primers, rupturing upon damage and releasing the healing agent to mitigate crack propagation and bolster structural integrity autonomously by extending the service life of the composite. The research provides valuable insights into optimizing the performance and durability of GFRP composites. Potential applications span across aerospace, automotive, and structural engineering domains.

Development of solid dispersion system from milk thistle dry extract by solvent method

Introduction. Silymarin is one of the main components used in preparations for hepatotropic therapy. Silymarin is contained in the dry extract of seeds and fruits of milk thistle (Silybum marianum L. Gaertn.), however it has poor bioavailability due to the crystalline state and low solubility of silymarin flavolignans in water at room temperature, as well as their poor absorption. One of the methods for increasing the bioavailability of medicinal substances consists in their introducing into solid dispersion systems (SDS). The most suitable method for obtaining SDS with extracts is the solvent method, since it does not require the use of a high temperature regime during the obtaining process of SDS.Aim. To develop the technology for solid dispersion system from milk thistle dry extract by solvent method to increase the bioavailability of this phytosubstance.Material and methods. The obtaining of the solid dispersion systems from milk thistle dry extract by solvent method was carried out with polyvinylpyrrolidone (PVP K-29/32), polyvinylpyrrolidone vinyl acetate 6 : 4 (PVPVA 64), hydroxypropylmethylcellulose (HPMC), gelatin and sodium lauryl sulfate (SLS). The quality indicators of the SDS: particle size distribution, bulk density, residual humidity and hygroscopicity were carried out according to the methods of the State Pharmacopoeia of the Russian Federation (GP RF) XV edition. The quantitative determination of biologically active substances (BAS) was carried out in accordance with the GP RF XV ed. by the amount of flavolignans in terms of silybin.Results and discussion. During the development of solid dispersion systems by solvent method, SDS samples from milk thistle dry extract (MTDE) with different polymers were studied. As a result of studying the particle size distribution, several SDS samples were selected. The SDS samples were compared with the MTDE sample. The "Dissolution" test showed that the micronization of MTDE in form of SDS by solvent method, containing polyvinylpyrrolidone vinyl acetate – PVP VA 64 is the best alternative for increasing the silybin releasing-degree from the extract and increasing its bioavailability. According to the content of the sum of flavolignans in terms of silybin, the selected SDS sample meets the requirements of the normative documentation for milk thistle dry extract. In addition, the conditions for the development of SDS do not significantly affect the quantitative content of silybin compared with the content of the control sample of MTDE. The technological characteristics of SDS have been investigated and their qualitative improvement compared to the MTDE sample has been established. The interaction between the polymer carrier and the milk thistle extract was evaluated by the IR-fourier spectroscopy method.Conclusion. The SDS from milk thistle dry extract was developed by solvent method. For the developed SDS, quality indicators such as the content of the sum of flavolignans in terms of silybin, residual humidity, bulk density, particle size distribution and hygroscopicity were determined. The solid dispersion system from milk thistle extract was analyzed by IR-fourier spectroscopy. The physico-chemical compatibility between the milk thistle extract and the polymer-carrier polyvinylpyrrolidone vinyl acetate is shown. The development of the SDS from milk thistle dry extract significantly increased the bioavailability of the phytosubstance by increasing the silybin releasing-degree of the SDS by 3 times compared with the control sample of MTDE.

Synergy of sodium dodecyl sulfate and citric acid in removing bacterial biofilms in hydroponic farming facilities.

This research explored various concentrations of sodium dodecyl sulfate (SDS) and citric acid (CA), both individually and in combination, to assess their effectiveness against Salmonella biofilms in hydroponic agriculture systems. Results demonstrated that a combined sanitizer of 0.1% SDS (1.0±0.1 log reduction when used alone) and 1% CA (1.4±0.3 log reduction when used alone) was highly effective in eliminating Salmonella biofilms from PVC pipes in hydroponic systems, reducing biofilm levels to below detectable limits (> 5.6 log reduction when used in combination). Confocal laser scanning microscopy (CLSM) showed significantly greater proportions of damaged/dead cells in the 0.1% SDS- and 1% CA-treated samples (82.6±2.6%) than in the single treatment with 0.1% SDS (26.1±3.0%) and 1% CA (31.6±2.5%) (P<0.05). Fourier transform infrared (FTIR) spectroscopy together with analysis of proteins and polysaccharides in the extracellular polymeric substances (EPS) of the biofilm matrices showed that the treatment not only affected bacterial viability but also significantly reduced the biomass of the biofilm. In summary, this research provides a foundation for the development of improved cleaning protocols in hydroponic systems, promoting safer and more sustainable farming practices.

Unlocking the Catalytic Potential of Anionic Micelles: Insights into the Ce(IV)-Directed Phenylalanine Oxidation Kinetics in Asymmetric Hydrophobic Environments.

The oxidation kinetics of phenylalanine (Phe) by Ce(IV) have been examined in both the absence and presence of aqueous micellar media with asymmetric tails, specifically using sodium dodecyl sulfate (SDS) and sodium tetradecyl sulfate (STS) surfactants. The reaction progress was monitored by observing a decrease in absorbance using UV-vis spectroscopy. Interestingly, the kinetic profile revealed a consistent increase in the observed rate constant values as the concentration of the surfactant increased. The kinetic results have been analyzed by using numerous experimental studies, such as dynamic light scattering (DLS), zeta potential, 1H NMR analysis, FT-IR spectroscopy, conductometry, scanning electron microscopy (SEM), fluorometry, time-correlated single-photon counting (TCSPC), and transmission electron microscopy (TEM). Micellar aggregates maintain their spherical shape in the presence of the substrate, even at higher surfactant concentrations, as revealed by microstructural analysis. The substrate molecules are encapsulated to a greater extent in the inner micellar core of STS micelles on account of the more hydrophobic nature of STS surfactants. Therefore, in STS micellar media, fewer substrate molecules diffuse to the Stern layer compared to the SDS micellar medium, resulting in fewer molecules participating in the oxidative transformation reaction. As a result, the rate enhancement of oxidation kinetics is less pronounced in STS micelles than in SDS micelles. A plausible mechanism that aligns with the kinetic results has been highlighted, along with the interpretation of the Piszkiewicz model, to explain the observed catalytic effect of both micellar mediums.

A Tale of Two Tails: Tail Ordering of Stoichiometric 1:1 DTAB:SDS Pairs Adsorbed at the Oil-Water Interface.

Cationic:anionic surfactant mixtures adsorbed at an oil-water interface stabilize foams in the presence of oil, making them essential to the oil, gas, and firefighting industries. The oil tolerance of foams stabilized by surfactant mixtures, relative to pure (unmixed) cationic and anionic surfactants, results from the mixtures' enhanced flexibility in tailoring the physicochemical properties of the interface. To judiciously employ these mixtures, it is necessary to characterize the structure-function property relationship of their surfactant monolayers that lend to oil-tolerant/intolerant foams. In this work, we employ interfacial tensiometry and vibrational sum frequency spectroscopy to determine the composition (surfactant population and cationic:anionic ratio) and the structure (surfactant alkyl tail conformation) of monolayers prepared at the oil-water interface by 1:1 DTAB:SDS (dodecyltrimethylammonium bromide:sodium dodecyl sulfate) mixtures. We show that the interfacial surfactant density of 1:1 DTAB:SDS mixtures greatly exceeds that of pure DTAB and SDS at similar concentrations up to and beyond their respective critical micelle concentration. The enhanced interfacial adsorption of these mixtures is due to the adsorption of stoichiometric 1:1 DTAB:SDS surfactant pairs that form through the attractive electrostatic interactions between surfactant headgroups. We find that these paired surfactants preferentially adsorb at the interface, causing the interfacial DTAB:SDS ratio to be nearly 1:1. Additionally, we find that the SDS tail is more conformationally ordered than the DTAB tail, even though they are expected to be conformationally identical along the entire tail, since they are likely conjoined through van der Waals interactions. This leads to the conclusion that the surfactant pairs are in a staggered arrangement at the interface. These findings help to uncover molecular factors that contribute to the enhanced oil tolerance, and in some cases oil intolerance, of foams stabilized by cationic:anionic surfactant mixtures.

Parameters Governing Void Formation and Expansion of Hollow Natural Rubber Latex Particles for Their Use as Bio‐based Nanocapsules

AbstractThis work reports the hollow latex (HL) particles developed from natural rubber latex particles (NRPs), known for their broad size distribution and non‐spherical shape. HL‐NRPs, prepared via the seeded emulsion polymerization in one pot, are studied as potential bio‐based nanocapsules for the first time. Effects of types of crosslinking agents and swelling agents, the addition of sodium dodecyl sulfate (SDS), and monomer compositions on the void formation and expansion are systematically investigated. The combined effects of phase separation between NR core swelled with divinyl benzene (DVB) and hydrophilic poly(methyl methacrylate/acrylic acid) P(MMA/AA) shell, the entanglement of rubber chains copolymerized with MMA/DVB/AA monomers, and the osmosis from external aqueous medium promoted the void formation. While crosslinking agents affected the void formation and shell strength, SDS and type of monomers governed colloidal stability and polymerization loci as well as morphology, respectively. The ability of HL‐NRPs as nanocapsules is explored by encapsulating fluorescent dyes, i.e., hydrophilic fluorescein isothiocyanate (FITC) and lipophilic Nile red (NiR), as model cargo. From the dye release test after 24 h, the cumulative concentrations of FITC in methanol and of NiR in tetrahydrofuran are 0.17 and 0.11 µg mL−1, respectively. The results suggested that FITC is released from HL‐NRPs easier than NiR possibly due to the different encapsulation location.

Characterization of a novel subfamily 1.4 lipase from Bacillus licheniformis IBRL-CHS2: Cloning and expression optimization.

This study focuses on a novel lipase from Bacillus licheniformis IBRL-CHS2. The lipase gene was cloned into the pGEM-T Easy vector, and its sequences were registered in GenBank (KU984433 and AOT80658). It was identified as a member of the bacterial lipase subfamily 1.4. The pCold I vector and E. coli BL21 (DE3) host were utilized for expression, with the best results obtained by removing the enzyme's signal peptide. Optimal conditions were found to be 15°C for 24 h, using 0.2 mM Isopropyl β-D-1-thiogalactopyranoside (IPTG). The His-tagged lipase was purified 13-fold with a 68% recovery and a specific activity of 331.3 U/mg using affinity purification. The lipase demonstrated optimal activity at 35°C and pH 7. It remained stable after 24 h in 25% (v/v) organic solvents such as isooctane, n-hexane, dimethyl sulfoxide (DMSO), and methanol, which enhanced its activity. Chloroform and diethyl ether inhibited the lipase. The enzyme exhibited the highest affinity for p-nitrophenol laurate (C12:0) with a Km of 0.36 mM and a Vmax of 357 μmol min-1 mg-1. Among natural oils, it performed best with coconut oil and worst with olive oil. The lipase was stable in the presence of 1 mM and 5 mM Ca2⁺, K⁺, Na⁺, Mg2⁺, and Ba2⁺, but its activity decreased with Zn2⁺ and Al3⁺. Non-ionic surfactants like Triton X-100, Nonidet P40, Tween 20, and Tween 40 boosted activity, while Sodium Dodecyl Sulfate (SDS) inhibited it. This lipase's unique properties, particularly its stability in organic solvents, make it suitable for applications in organic synthesis and various industries.

Preparation of high-performance Na2+2xFe2-x(SO4)3 cathode material by combining sodium dodecyl sulfate with carbon nanotubes

Preparation of high-performance Na2+2xFe2-x(SO4)3 cathode material by combining sodium dodecyl sulfate with carbon nanotubes

Effect of Mixed Surfactant on Evaporation Driven Salt Crystallization Morphology in Sessile Droplets.

Extensive studies have been conducted to manipulate the morphology of sodium chloride salt crystals to tailor their physical and chemical properties. Among the myriad factors considered, the effects of the substrate and additives have profound impacts on the types of salt depositions. Surface charge effects and various ionic surfactants influence ion movement, resulting in diverse crystal morphologies. This manuscript aims to provide a consolidated summary by concurrently studying multiple effects to uncover the salt crystal morphology under the influence of two oppositely charged ionic surfactants on charged and neutral surfaces. The cationic surfactant cetyltrimethylammonium bromide induces skeletal crystal growth by retarding salt precipitation until supersaturation is reached. Conversely, the anionic surfactant sodium dodecyl sulfate hinders ion diffusion at the three-phase contact line. Each surfactant effect is dominant at higher molar concentrations. Surface charge affects the amount of surface adsorption and free-moving ions within the saline surfactant droplets, greatly influencing the number of salt crystals formed on the neutral substrate. However, charge neutralization at the highest concentrations of both surfactants nullifies the surface charge effect, resulting in practically indistinguishable salt crystals with similar sizes and numbers, leading to only a small area difference of 1461 μm2. This study provides insights into the kinetics of crystallization under the combined influence of anionic, cationic, and surface charge interactions. The findings can serve as a future reference for predicting and controlling ionic interactions and crystal morphology.

The Heme Cavity Is Essential for the Peroxidase and Antibacterial Activity of Homodimer Hemoglobin from the Blood Clam Tegillarca granosa

This study investigates the essential role of the heme cavity in the peroxidase and antibacterial activities of homodimeric hemoglobin (Tg-HbI) from the blood clam Tegillarca granosa. After treatment with sodium dodecyl sulfate (SDS), the peroxidase and antibacterial activities of the Tg-HbI were significantly inhibited, with the degree of inhibition correlating positively with the SDS concentration. Fluorescence spectroscopy, UV-Vis spectroscopy, and molecular docking analysis further revealed that SDS interacts with key amino acid residues (e.g., His70 and His102) in the heme cavity of Tg-HbI, causing conformational changes that disrupt the internal hydrophobic interactions, thus inhibiting its function. This study confirms that the antibacterial effect of Tg-HbI is mediated through its peroxidase activity and that the heme cavity plays a critical role in maintaining this activity. These findings lay a foundation for further research on the immune defense functions of hemoglobin and provide new insights into the mechanisms of environmental adaptation in T. granosa.

Preparation and Characterization of an Environmentally Friendly Dust Suppressant for Crust in a Nondisturbance Area of an Open Limestone Mine

ABSTRACTTo solve problems caused by dust pollution in open limestone mines, environmental dust suppressants were prepared with natural polymer extracts as raw materials. The proportion range of guar gum (GG), sodium carboxymethyl cellulose (CMC), and sodium dodecyl sulfate (SDS) as the single components of the composite dust suppressant (CDS) was determined by a single‐factor test. Response surface methodology (RSM) was used to optimize the mix design, and the weather resistance, compressive strength, and cost of CDS were tested and compared with many commercial dust suppressants. Microscopic tests were used to analyze the structural properties and functional group changes in CDS. The results showed that the optimal concentration of the CDS agent was 0.192% GG, 0.3% CMC, and 0.351% SDS. Under the optimal ratio, the viscosity of CDS was 119.56 mPa∙s, the pH was 7.62, the surface tension was 30.3 mN/m, and the price was 83.3 RMB/t. The dust hardness after 7 days of spraying CDS was 87 HA. CDS exhibits good resistance to rain erosion, pressure resistance, freeze–thaw resistance, and wind erosion. CDS formed a cross‐linked structure by linking the amide and carboxyl groups, which can significantly reduce porosity, and form a compact and flat solidified layer, which has good dust suppression performance.

Dipole interaction of particles in magnetic fluid stabilized by a double layer of surfactant in water

Purpose of the work: to study the influence of interparticle dipole-dipole interactions on the susceptibility of a magnetic fluid stabilized by a double layer of surfactant in water.Research method consists in measuring the initial differential susceptibility of a magnetic fluid depending on its concentration. Three samples of fluid based on magnetite particles, differing in the composition of the stabilizing shells, were studied. The following acids were used as the first layer of the stabilizer: lauric (C12), decanoic (C10) and octanoic (C8). The second layer of the stabilizing shell was formed by sodium dodecyl sulfate with a small proportion of the corresponding acid. Susceptibility measurements were performed on a setup for measuring magnetization curves. The concentration of the samples was determined by their saturation magnetization.Results. The concentration dependences of the initial susceptibility were measured for three samples of magnetic fluid based on magnetite particles. The obtained results were compared with theoretical models of the modified effective field of A.O. Ivanov and the average-spherical one. Both theories predict overestimated values of susceptibility in relation to experimental values. The modified effective field theory overestimates the results by 20%. The mean-spherical model - by 12%. It is shown that the correct interpretation of the concentration dependence of the susceptibility of magnetic fluid samples is possible only by approximating the ratio of susceptibility to saturation magnetization. Based on this approximation, an empirical formula in the form of a third-degree polynomial with a negative cubic term is proposed to describe the concentration dependence of susceptibility.Conclusion. Thus, the obtained results require the construction of new or modification of old theories of dipole-dipole interaction of magnetic particles in aqueous colloidal solutions with stabilization of particles by a double layer of surfactant.

A Review of Herbal Toothpaste Formulation, and Efficacy in Oral Care

The increasing consumer shift toward natural, plant-based, and eco-friendly products has significantly contributed to the rise in popularity of herbal toothpastes in the global oral care market. Herbal toothpastes, formulated using plant-based extracts, offer a safe and sustainable alternative to traditional synthetic toothpastes, which often contain chemicals such as fluoride, sodium lauryl sulfate, and artificial preservatives. This review paper aims to explore the key ingredients, formulation processes, and evaluation methods used in the development of herbal toothpaste, with a particular focus on their therapeutic properties, efficacy, and safety. Herbal toothpastes are typically composed of herbal extracts known for their medicinal benefits, such as neem, clove, aloe vera, tea tree oil, and peppermint, which provide antibacterial, anti-inflammatory, and antioxidant properties. Additionally, natural abrasives like calcium carbonate and silica are included for plaque removal, while natural binders and thickeners ensure proper consistency. The formulation process involves the careful selection of these ingredients, their extraction, and the preparation of a stable, homogeneous paste. Evaluation of herbal toothpaste is essential to ensure its safety, efficacy, and consumer acceptability. Microbial testing is conducted to determine the toothpaste’s ability to inhibit oral pathogens, while sensory evaluation assesses taste, texture, and aroma. Clinical studies are performed to evaluate the product's impact on gum health, plaque reduction, and remineralization of enamel. Moreover, parameters such as abrasivity and pH levels are rigorously tested to ensure that the toothpaste does not damage tooth enamel or irritate gums.

Study on the Influence of Surfactant Solution on the Wetting and Chemical Structure Characteristics of Coal at Different Temperatures.

To reduce the production of dust in the coal mine production process, the surface tension and contact angle of the solution at different temperatures were measured, and the temperature range of the surfactant to achieve the best wetting effect during the coal seam water injection was determined. The results show that the surface tension and contact angle of sodium dodecyl sulfate (SDS) and sodium dodecylbenzenesulfonate (SDBS) and of SDS and polysorbate 80 (Tween80) decrease rapidly at first and then increase slowly with the increase of temperature, the minimum surface tension values were 26.293 and 27.726 mN/m, and the minimum values of contact angles were 89.35 and 65.1°, respectively. The two kinds of composite solutions have the best wetting effect at 35-40 °C. In addition, the influence of surfactants on the chemical structure of coal under different temperature conditions was analyzed, and the variation rule between the chemical structure and the wetting property of coal was explored. The research results have important practical guiding significance for reducing dust generation in a coal mine.

Phytochemical profiling and fractionation of Helianthemum lippii extract versus silver nanoparticle-modified extract: assessment of photoprotective, anti-hemolytic, antibacterial, and anti-inflammatory properties

IntroductionThis study investigates the synthesis of silver nanoparticles (Ag NPs) using Helianthemum lippii extract and evaluates their photoprotective, anti-hemolytic, antibacterial, and anti-inflammatory properties compared to various extract fractions, including total aqueous extract (AE), flavonoid monoglycosides (FMG), flavonoid diglycosides/triglycosides (FDG/FTG), tannins (TN), and anthocyanins (AC). Helianthemum lippii is rich in bioactive compounds such as caffeic acid, p-coumaric acid, and gallic acid, known for their therapeutic potential. This study aims to determine whether embedding these phytochemicals into Ag NPs enhances their biomedical applications compared to the natural extract fractions.MethodsAg NPs were synthesized using Helianthemum lippii extract through a green synthesis approach, and their physicochemical properties, including size and morphology, were characterized. High-performance liquid chromatography (HPLC) was used to identify key phytochemicals in the various extract fractions. Biological assays were conducted to assess photoprotective efficacy (sun protection factor, SPF), antibacterial activity (minimum inhibitory concentration, MIC), anti-inflammatory potential (percentage inhibition), and hemolytic properties, with sodium dodecyl sulfate (SDS) serving as a control.ResultsHPLC analysis confirmed the presence of bioactive compounds, including caffeic acid, p-coumaric acid, and gallic acid, in the AE extract. The Ag NPs were spherical with an average diameter of 35 nm and had phytochemicals adsorbed on their surface. The AC fraction demonstrated the highest SPF (28.27), followed by TN (27.99), AE (23.20), and Ag NPs (22.50), while FMG exhibited a moderate SPF (19.39) compared to the commercial sunscreen Avene® (40.00). Ag NPs exhibited superior antibacterial activity with MIC values of 0.2 mg/mL against Pseudomonas aeruginosa and 0.4 mg/mL against Bacillus subtilis, outperforming AE, which had a MIC of 2.81 mg/mL. Anti-inflammatory assays showed that Ag NPs achieved 79.8% inhibition at 400 μg/mL, surpassing AE (71.75%) and TN (67.9%), and were comparable to diclofenac (72.63%). Hemolysis assays revealed that Ag NPs induced only 1.35% hemolysis, lower than AE (1.91%) and significantly below SDS (90.48%).DiscussionThe findings demonstrate that Helianthemum lippii-derived Ag NPs exhibit enhanced antibacterial, anti-inflammatory, and anti-hemolytic properties compared to the extract fractions. While the SPF of Ag NPs was slightly lower than the AC and TN fractions, their superior multifunctional bioactivities underscore their potential for various biomedical applications. The integration of phytochemicals into Ag NPs significantly enhances their therapeutic efficacy, making them promising candidates for advanced pharmaceutical formulations and topical protective agents.

Comparison of Pressurized Water Extraction With Ultrasound Assisted Extraction for Isolation of Phycobiliproteins From Arthrospira platensis (Spirulina).

Cyanobacterium Arthrospira platensis (AP) (Nordstedt) Gomont contains high content of phycobiliproteins (PBP), which are an important source for food industry. Methods effectively extracting proteins contained in AP cells are demanded to provide a supply of the material. Water-based extraction methods are advisable due to the high solubility of the PBP. Extraction techniques such as ultrasound assisted extraction (UAE) and pressurized water extraction (PWE) are popular due to their environmental friendliness, better extraction efficiency, and faster extraction process. In this paper, efficiency of the two methods is compared. PWE along with UAE is utilized for release of PBP from the AP cells. The extraction parameters including time, temperature, pressure, and ultrasound intensity are tested to obtain the most efficient setup. The methods were evaluated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the replicates of PWE extracts were further analyzed by capillary isoelectric focusing with laser-induced fluorescence (cIEF-LIF). The developed PWE method using higher pressure treatment at lower temperature was significantly faster than UAE methods, and the SDS-PAGE results showed a high content of phycobiliproteins in the extracts. cIEF-LIF analysis showed that the sequential PWE of individual samples was repeatable, and the mild extraction provided a fluorescent profile similar to the commercially available C-phycocyanin standard. Pressurized water extraction was shown to be an efficient, rapid, and well-automated extraction method for AP proteins in general, including bioactive phycobiliproteins. Obtained results encourage the use of PWE in small-scale analytical applications for primary extraction of proteins.

Efficient, Low-Cost, and High-Throughput Sodium Dodecyl Sulfate (SDS) Removal from Protein Digests Using Weak-Anion Exchange.

Sodium dodecyl sulfate (SDS) plays a pivotal role in protein denaturation, tissue extraction, and protein mass-based electrophoretic separations. However, even modest concentrations of SDS can cause column overpressure, retention time shifts, and ionization signal suppression during liquid chromatography-tandem mass spectrometry (LC-MS/MS) analyses. Thus, SDS removal is a critical step for LC-MS/MS analysis of protein digests containing SDS. This study describes an inexpensive and high-throughput method to remove SDS from protein digests using weak-anion exchange (WAX) resins in 96-well filter plates. Requiring less than 3 min, this method can reduce SDS concentrations from 0.1-0.4% to less than 5 ppm and from 0.6-1% to less than 100 ppm. After SDS removal, the recoveries of unmodified tryptic peptides and phosphorylated peptides (at 94.3 nM) were ∼90% and ∼70%, respectively. Additionally, when using aqueous 1% SDS to solubilize trastuzumab-spiked mouse serum and subsequently removing the SDS using the WAX resin, quantitation of trastuzumab exhibited excellent linearity (R2 = 0.9996) together with a low coefficient of variation (<10%). Calculated concentrations were within 20% of the expected value for spiked standard samples (0.5, 1, and 2 μg/mL trastuzumab in mouse serum). The method is about 20× more cost-effective versus commercialized SDS removal kits and both the resin and filter plate are readily available, so the method should easily transfer to other laboratories.

Bacterial Cellulose Purification with Non-Conventional, Biodegradable Surfactants

Bacterial cellulose (BC) is a versatile biopolymer with significant potential across biomedical, food, and industrial applications. To remove bacterial contaminants, such as protein and DNA, BC pellicles undergo purification, which traditionally relies on harsh alkali treatments, such as sodium hydroxide or strong surfactants, which present environmental concerns. In response, this study evaluates the efficacy of various non-conventional surfactants—both non-biodegradable and biodegradable—as alternatives for BC purification. Among the surfactants tested, sodium cocoyl isethionate (SCI), a mild anionic and biodegradable surfactant, emerged as particularly effective, achieving an 80.7% reduction in protein content and a 65.19% reduction in double-stranded DNA (dsDNA) content relative to untreated samples. However, these advantages were not without additional challenges, such as the appearance of residual surfactants. Given SCI’s promising performance and biodegradability, it was further examined in two-step treatment protocols; additionally, sodium dodecyl sulfate (SDS) was also examined as a more traditional anionic surfactant as well as NaOH. For the two-step treatment protocol, BC pellicles were treated with one reagent for 3 h, followed by a second reagent for an additional 3 h. Notably, by using NaOH as the final step in the two-step treatment protocol, residual surfactant was not detected in the FTIR analysis. Overall, this work demonstrates that SCI, in addition to subsequent NaOH treatment, can be used as a surfactant-based approach for BC purification, representing a potential environmentally friendly alternative to traditional surfactant-based approaches for BC purification.