Sodium Dodecyl Sulfate Group Research Articles

Effect of monovalent and divalent salts on the interfacial and structural properties of vapor-liquid water interface in presence of sodium dodecyl sulfate

The impact of divalent cations on the interfacial and structural properties of the vapor–liquid water interface covered with an anionic surfactant such as sodium dodecyl sulfate (SDS) is of great relevance to several industrial applications. In the present work, all-atom molecular dynamics simulations are performed to investigate the interfacial and structural properties of the vapor-SDS-liquid water interface with divalent salts viz., CaCl2 and MgCl2. The surface tension rises with the rise in divalent salt concentration, whereas it remains almost constant with NaCl concentration. In the absence of divalent salts, the accumulation of Na+ ions near the SDS headgroups is observed. Conversely, in the systems with divalent salts, the divalent cations (Ca2+ and Mg2+) enriched beside the SDS monolayer cause the monovalent cations (Na+) to displace from the interface into the bulk. The structural analysis shows that Na+ and Ca2+ cations enter the first hydration shell of the sulfate group of SDS. On the other hand, Mg2+ usually coordinates with the sulfate group of SDS. The potential of mean force (PMF) shows that the escape free energy of divalent cations is higher than monovalent cations, and the interaction between the cations and sulfate head group of SDS follows the order: S-Ca2+ > S-Mg2+ > S-Na+.

Functionalized Metal-Organic Framework for Selective Fluorometric Detection of Sodium Dodecyl Sulfate and Vitamin B12 Using MOF@Cotton Composites and Lewis Base-Catalyzed Condensation Reaction.

A zirconium(IV)-based metal-organic framework (MOF) fluorophore containing the 2,5-diaminoterephthalic acid (H2BDC-(NH)2) linker was synthesized and characterized. The physicochemically stable, porous (SBET = 504 m2 g-1) MOF (1') exhibited selective and sensitive fluorescence turn-on behavior toward the sodium dodecyl sulfate (SDS) surfactant and turn-off response toward vitamin B12. This is the first ever reported MOF-based dual optical sensor of SDS and vitamin B12. Other competitive analytes did not interfere in the detection of both the analytes. Along with the lowest ever reported limit of detection (LOD) values (LOD for SDS = 108 nM and LOD for vitamin B12 = 45.3 nM), 1' displayed short response time for SDS (50 s) and vitamin B12 (5 s) detection. The MOF was able to detect SDS in various real water samples and vitamin B12 in various bio-fluids (urine and serum) and pH media. A MOF-coated cotton composite was fabricated, which displayed a visible color change under UV light even after treating it with a nanomolar concentration of both the analytes. The sensor displayed excellent reusability up to five cycles of sensing. Various experimental outcomes evidenced that the electrostatic interaction between the -NH2 groups of the linker and the -SO3- group of SDS is the possible reason for the selective SDS sensing. For vitamin B12, the energy transfer from the probe to vitamin B12 resulted in fluorescence quenching. In addition, the catalytic performance of 1' was investigated in the condensation reaction between benzaldehyde derivatives with cyanoacetamide with high yields in ethanol at 70 °C. The solid was used for three cycles with no decrease in its activity and selectivity. PXRD and FESEM analysis before and after the reaction suggested the retention of the crystallinity of 1', thus indicating catalyst stability.

Comparison of Sodium Lauryl Ether Sulfate and Sodium Dodecyl Sulfate in the Intestinal Decellularization of Rats Using a Histological Method and Confocal Raman Microscopy

Background: Sodium dodecyl sulfate (SDS) detergent is widely used in tissue decellularization to produce scaffolds for tissue engineering. Despite its strong decellularization, this substance has relatively high toxicity and causes changes in tissue composition. Sodium lauryl ether sulfate (SLES) is a new poly anionic detergent that is less toxic than SDS but weaker than it. The present study aimed to decellularize the intestinal tissue using SDS and SLES solutions, forming a cell scaffold, and examining scaffolds obtained from this tissue. Methods: Eighteen male Sprague-Dawley rats were divided into three groups. The intestines of all rats were removed after anesthesia. In the first group (controls), rats’ intestines were placed in a 10% formalin solution. In the second group, intestines were decellularized using an SLES solution. In the third group animals’ intestines were decellularized using an SDS solution. To evaluate decellularization, samples were stained with hematoxylin-eosin staining and Alcian blue staining for glycosaminoglycans (GAGs), and Masson’s trichrome for collagen fibers. A confocal Raman microscope was used to compare collagen, lipid, GAG, and genetic content. Results: Hematoxylin-eosin staining showed that the nucleus and DNA were removed in the decellularized scaffolds by SDS or SLES. The SLES group, compared to the SDS group, showed fewer changes in the epithelial tissue, and muscle layers in both scaffolds were well preserved. The results of confocal Raman microscopy showed that tryptophan, lipid, glycogen, and protein were broken down by both detergents; however, the residual amount of glycogen was the same in both substances, but disulfide bonds of proteins, hydroxyproline, and lipids in the decellularized intestine with SLES were mostly preserved. Conclusion: Both substances were suitable for intestinal decellularization and removed the overall structure of intestinal tissue, but SLES retained collagen and GAG content better than SDS.

Investigating the effects of surfactants on Chlorella pyrenoidosa in the hydrolysis acidification liquor by integrated physiochemical and transcriptome analyses

In our two recently published articles, we investigated the effects of Tween 80, sodium lignosulfonate (LS), sodium dodecyl sulfate (SDS), and rhamnolipid (RL) on the co-conversion of endogenous carbon (C) and nitrogen (N) of dairy wastewater in the hydrolytic acidification coupled microalgae culture system. Although the effects of surfactants on the microalgae (Chlorella pyrenoidosa) growth from the perspective of enhancing the accumulation of the volatile fatty acids (VFAs) were investigated, the question regarding the effect of surfactants themselves on microalgae growth and mechanism remains to be addressed. In this work, we extend our discussion to clearly demonstrate the effects of these four surfactants on microalgae growth, nutrient removal, and the output of the culture system in artificial hydrolysis-acidification liquor (HAL). Furthermore, de novo transcriptome profiling and the metabolic pathway analysis of C. pyrenoidosa cells in response to these four surfactants were also performed. The results showed that SDS inhibited while the other three surfactants promoted microalgae growth (promotion order of dry weight: Tween 80 > RL > LS). The maximum ammonia nitrogen removal rate followed Tween 80 80.90 % > RL 78.32 % > LS 75.23 % > control 67.08 % > SDS 34.74 %. Surfactants enhanced the C assimilation followed Tween 80 > RL ≈ LS > control. Tween 80, RL, and LS treatment groups achieved higher yield of protein, carbohydrates, and lipid. The differential transcriptome analysis revealed that the number of down-regulated differential expression of unigenes (DEUs) more than that of up-regulated in SDS group, while the opposite was true for the other 3 surfactants. KEGG enrichment analysis revealed that Tween 80 mainly affects lipid metabolism in the early stage of microalgae growth, RL mainly affects lipid metabolism and membrane transport, SDS mainly affects energy metabolism, lipid metabolism, and transport and catabolism, while no DEUs significant enriched KEGG in LS group.

Passivation of corrosion product layer on AM50 Mg by corrosion inhibitor

The influence of sodium dodecyl sulfate (SDS) on morphology and chemical composition of corrosion product layer formed on α-Mg matrix and cathodic Al-Mn intermetallic was systematically investigated by using FIB and TEM analysis for the first time to disclose the underlying inhibition mechanism. A porous corrosion bi-layer composed of crystalline MgO and Mg(OH) 2 was observed on both of α-Mg and Al-Mn intermetallic. It was found that a passive inner layer was deposited on α-Mg after immersion in SDS-containing NaCl solution, which can be ascribed to steady-state growth of magnesium and aluminum oxide under the protection of hydrophobic group of SDS. The inhibition mechanism of the inhibitor was mainly associated with formation of dense oxide layer on α-Mg matrix and preferential adsorption of SDS on the corrosion layer deposited on Al-Mn intermetallic.

Hierarchical layered double hydroxide for the removal of charged dyes: the role of an anionic surfactant

AbstractHierarchical layered double hydroxide (HLDH) was synthesized by using sodium dodecyl sulfate (SDS) as a soft-template agent for the removal of two charged organic dyes (i.e. methylene blue (MB; cationic dye) and methyl orange (MO; anionic dye)). The experimental results based on response surface methodology (RSM) demonstrated distinct removal behaviours of HLDH towards these two dyes: (1) the maximum capacity was 416.7 mg g–1 for MO and 58.7 mg g–1 for MB at 25°C; (2) the increase in temperature could enhance MO removal significantly, whereas it had a negligible effect on the MB treatment process; and (3) rapid removal of MB (5 min) compared to MO (480 min) was observed. In addition, the removal process for both dyes was pH-independent. Multiple characterization techniques further revealed the removal mechanisms, demonstrating that SDS played a significant role in the removal of both dyes; that is, MO replaced SDS to be intercalated into the HLDH interlayer via anion exchange. MB could influence the –SO3 group of SDS, resulting in it modifying the electrodensity of SDS. It could then be further combined with an SDS anion (DS–) via hydrophobic and electrostatic interactions to form DS-MB monolayers. This work not only provides an efficient capture agent for charged dyes, but also offers a deep insight into the underlying removal mechanism.

Decellularization of kidney tissue: comparison of sodium lauryl ether sulfate and sodium dodecyl sulfate for allotransplantation in rat.

An automatic decellularization device was developed to perfuse and decellularize male rats' kidneys using both sodium lauryl ether sulfate (SLES) and sodium dodecyl sulfate (SDS) and to compare their efficacy in kidney decellularization and post-transplantation angiogenesis. Kidneys were perfused with either 1% SDS solution for 4h or 1% SLES solution for 6h. The decellularized scaffolds were stained with hematoxylin and eosin, periodic acid Schiff, Masson's trichrome, and Alcian blue to determine cell removal and glycogen, collagen, and glycosaminoglycan contents, respectively. Moreover, scanning electron microscopy was performed to evaluate the cell removal and preservation of microarchitecture of both SDS and SLES scaffolds. Additionally, DNA quantification assay was applied for all groups in order to measure residual DNA in the scaffolds and normal kidney. In order to demonstrate biocompatibility of the decellularized scaffolds, human umbilical cord mesenchymal stromal/stem cells (hUC-MSCs) were seeded on the scaffolds. In addition, the allotransplantation was performed in back muscle and angiogenesis was evaluated. Complete cell removal in both SLES and SDS groups was observed in scanning electron microscopy and DNA quantification assays. Moreover, the extracellular matrix (ECM) architecture of rat kidney in the SLES group was significantly preserved better than the SDS group. The hUC-MSCs were successfully migrated from the cell culture plate surface into the SDS and SLES decellularized scaffolds. The formation of blood vessels was observed in the kidney in both SLES and SDS decellularized kidneys. The better preservation of ECM than SDS introduces SLES as the solvent of choice for kidney decellularization.

Role of ionic surfactants on the nucleation and growth of silver nanoparticles

Sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) were used as stabilizers for the preparation of silver nanoparticles (AgNPs) by the reduction of silver nitrate with proanthocyanidines (Pas). UV–visible spectra shows that the surface Plasmon resonance (SPR) intensity of AgNPs increases and decreases with increasing SDS and became constant at higher concentration. CTAB has no effect on the nucleation of AgNPs due to the insolubility of Pas. The position of SPR band (λmax = from 438 to 476 nm) depends on the concentration of Pas and a red shift of 38 nm was observed in absence of externally added SDS. The micellar pseudo phase proposed by Menger and Portnoy, modified by Bunton was used to determine the rate constants in micellar media. The Ag+ ions were formed complex with negative head group (OSO3−) of SDS electrostatically. Raman scattering spectroscopy, transmission electron microscopy, and scanning electron microscopy were used to discuss the capping action of SDS. Zeta potential of SDS-capped AgNPs was negative and resulting sols were stable for many months.

QS9: Decellularization Of Vascularized Composite Allografts In The Rat

Purpose:The decellularization of Vascularized Composite Allotransplantation (VCA) represents a first step in circumventing the need for immunosuppression by depleting donor cells from VCAs. Here we present a model of decellularization of VCAs in rats.Methods:Rat hind limbs based upon the common femoral artery were harvested and perfused through the vascular pedicle at 1ml/min through with 1% sodium dodecyl sulfate (SDS) (group 1) or 0.2% SDS (group 2) or were immersed in SDS 1% (group 3), followed by perfusion (group 1 and 2) or immersion (group 3) in 1% Triton X-100. The degree of decellularization was assessed quantitatively by determining DNA content and qualitatively by histology in all groups at the same locations. The group yielding best decellularization outcome was selected for further assessment for the preservation of ECM content and vasculature and was transplanted orthotopically to assess the ability to reperfuse these decellularized limbs in vivo. RESULTS - Gross examination and DNA quantification of less than 50 ng/mg tissue demonstrated successful decellularization only in group 2 while preserving tissue matrix architecture, including vessels. The arterial network was found to be perfusable and intact during in vivo orthotopic transplantation of the decellularized limb. No outflow was observed, however, after 115 minutes of arterial reperfusion.Conclusions:We describe a successful decellularization protocol for rat hindlimb VCAs by perfusion ex-vivo of 1% SDS. During its in vivo transplantation, decellularization alone allows for a perfusable arterial network and with further optimization, we aim to achieve venous perfusion as well.

Extracellular matrix derived from allogenic decellularized bone marrow mesenchymal stem cell sheets for the reconstruction of osteochondral defects in rabbits

Bioactive scaffolds from synthetical polymers or decellularized cartilage matrices have been widely used in osteochondral regeneration. However, the risks of potential immunological reactions and the inevitable donor morbidity of these scaffolds have limited their practical applications. To address these issues, a biological extracellular matrix (ECM) scaffold derived from allogenic decellularized bone marrow mesenchymal stem cell (BMSC) sheets was established for osteochondral reconstruction. BMSCs were induced to form cell sheets. Three different concentrations of sodium dodecyl sulfate (SDS), namely, 0.5%, 1%, and 3%, were used to decellularize these BMSC sheets to prepare the ECM. Histological and microstructural observations were performed in vitro and then the ECM scaffolds were implanted into osteochondral defects in rabbits to evaluate the repair effect in vivo. Treatment with 0.5% SDS not only efficiently removed BMSCs but also successfully preserved the original structure and bioactive components of the ECM When compared with the 1% and 3% SDS groups, histological observations substantiated the superior repair effect of osteochondral defects, including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular cartilage integrated with native tissues in the 0.5% SDS group. Moreover, RT-PCR indicated that ECM scaffolds could promote the osteogenic differentiation potential of BMSCs under osteogenic conditions while increasing the chondrogenic differentiation potential of BMSCs under chondrogenic conditions. Allogenic BMSC sheets decellularized with 0.5% SDS treatment increased the recruitment of BMSCs and significantly improved the regeneration of osteochondral defects in rabbits, thus providing a prospective approach for both articular cartilage and subchondral bone reconstruction with cell-free transplantation.

Antimicrobial photodynamic therapy mediated by methylene blue in surfactant vehicle on periodontopathogens.

Periodontal disease (PD) is a chronic inflammatory disease caused by the presence of microbial biofilm. The aim of this study was to evaluate antimicrobial effect of antimicrobial photodynamic therapy (A-PDT) mediated by methylene blue (MB) in monomer form on A. actinomycetemcomitans and P. gingivalis. A. actinomycetemcomitans ATCC 29523 and P. gingivalis ATCC 33577 were cultured on anaerobic jars at 37 °C for 48 h, and we tested APDT in the presence of 0.25% sodium dodecyl sulfate (SDS) in phosphate-buffered saline (PBS) or in PBS alone. APDT was carried out with 100 μM MB under laser radiation (PhotolaseIII, DMC, Brazil) at ʎ =660 nm and parameters as following (P =100 mW; I =250 mW/cm2, and doses of 15, 45 and 75 J/cm2). Following A-PDT, PBS groups of A. actinomycetemcomitans presented 4 Logs of microbial death after 5 min irradiation. However, there was no bacterial reduction in SDS groups. On the other hand, P. gingivalis was sensitive to APDT in the presence of 0.25% SDS with 2 logs reduction from dark toxicity. The presence of 0.25% SDS can lead to different responses depending on the different microbial species.

Optimizing the formation of the acquired enamel pellicle in vitro for proteomic analysis

Saliva is the major contributor for the protein composition of the acquired enamel pellicle (AEP), a bacteria-free organic layer formed by the selective adsorption of salivary proteins on the surface of the enamel. However, the amount of proteins that can be recovered is even smaller under in vitro condition, due to the absence of continuous salivary flow. Objective This study developed an in vitro AEP protocol for proteomics analysis using a new formation technique with different collection solutions.Methodology 432 bovine enamel specimens were prepared (4x4 mm) and divided into four groups (n=108). Unstimulated saliva was provided by nine subjects. The new AEP formation technique was based on saliva resupply by a new one every 30 min within 120 minutes at 37ºC under agitation. AEP was collected using an electrode filter paper soaked in the collection solutions according with the group: 1) 3% citric acid (CA); 2) 0.5% sodium dodecyl sulfate (SDS); 3) CA followed by SDS (CA+SDS); 4) SDS followed by CA (SDS+CA). The pellicles collected were processed for analysis through LC-ESI-MS/MS technique.Results A total of 55 proteins were identified. The total numbers of proteins identified in each group were 40, 21, 28 and 41 for the groups CA, SDS, CA+SDS and SDS+CA, respectively. Twenty-three typical AEP proteins were identified in all groups, but Mucin was only found in CA and CA+SDS, while three types of PRP were not found in the SDS group. Moreover, a typical enamel protein, Enamelin, was identified in the CA+SDS group only.Conclusion The new technique of the in vitro AEP formation through saliva replacement was essential for a higher number of the proteins identified. In addition, considering practicality, quantity and quality of identified proteins, citric acid seems to be the best solution to be used for collection of AEP proteins.

Modulation of Surface-Catalyzed Secondary Nucleation during Amyloid Fibrillation of Hen Egg White Lysozyme by Two Common Surfactants.

Amyloid fibrillation by hen egg white lysozyme (HEWL) under the influences of two common surfactants, sodium dodecyl sulfate (SDS) and Triton X-100 (TX-100), was investigated with atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy. Detailed AFM investigations indicated that both SDS and TX-100 were able to induce some significant morphological changes of HEWL amyloid fibrils. Both SDS and TX-100 could induce a morphological change which was characterized with alternating fibril regions with increased thicknesses along the fibril axis. In addition, TX-100 was also able to induce a morphological change which was characterized with fibril branching. In contrast, the positively charged cetyltrimethylammonium bromide displayed no such effect as compared with the negatively charged SDS and the nonionic TX-100. These intriguing modulation effects of SDS and TX-100 on amyloid fibrillation were hypothesized to be due to surfactant-induced surface-catalyzed secondary nucleation owing to the noncovalent interaction between the surfactants and HEWL. The proposed hypothesis was further supported by FTIR spectroscopic investigation, which demonstrated the formation of a SDS-amyloid fibril complex and TX-100-amyloid fibril complex. Detailed FTIR analysis suggested that the tail group of SDS associated with amyloid fibrils is more disordered similar to that of SDS in aqueous solution, while the headgroup of SDS appears to interact with amyloid fibrils strongly similar to that of SDS in the solid state, and the ether groups of TX-100 associated with amyloid fibrils experienced a different microenvironment as compared with that of neat TX-100. Additional control experiments with FTIR spectroscopy revealed that the interactions of SDS/TX-100 with HEWL amyloid fibrils were different from those of SDS/TX-100 with HEWL amorphous aggregates. In addition, the β-sheet structures of the HEWL amyloid fibrils were found to be increased due to the influences of SDS and TX-100. Our work provides new insight into the modulation effects of surfactants on amyloid fibrillation.

Effects of reinforced nanoparticles with surfactant on surface quality and chip formation morphology in MQL-turning of superalloys

Superalloys (nickel and titanium-based alloys) are grouped as difficult-to-cut materials. Therefore, due to poor machinability of superalloys, their machining is a great challenge for manufacturing sectors. Surface quality of work part and chip formation morphology are considered as the main machinability attributes in machining superalloys. Although numerous studies have been focused on this context, however, no work was found on the effect of nanoparticles stability on nanofluid performance and consequently on machinability attributes, in principle surface quality and chip formation morphology. In the present study, the importance of nanoparticles stability by adding of surface active agent (surfactant) as additive elements was evaluated. Two kinds of nanoparticles including nano copper-oxide and nano silicon-oxide with different volume fraction were used to prepare nanofluid solution. In addition, surfactant from the group of Sodium Dodecyl Sulfate (SDS) which is appropriate for polar fluid was selected. Scanning Electron Microscope (SEM) images were utilized to analyse the machined surface of the work part. Cutting fluids were prepared in three conditions, including nanofluid with surfactant (reinforced nanofluid), nanofluid without surfactant, and conventional cutting fluid (without nanoparticles). The average surface roughness Ra was considered as the surface quality attribute. The recorded values of Ra and chip formation morphology indicated that reinforced nanofluid could significantly improve the cutting mechanism as compared with nanofluid without surfactant and conventional fluid. The main reason for this phenomenon can be attributed to high ability of surfactant to disperse nanoparticles in the fluid medium as well as high capability to prevent nanoparticles aggregation. After a short period, the nanoparticles in nanofluid without surfactant attached to other particles and a massive mass (nanoparticles aggregation) was formed which led to quick settling of nanoparticles. By settling of nanoparticles, the environment becomes free of nanoparticles and similar properties and capability as conventional fluid may occur.

Cartilaginous extracellular matrix derived from decellularized chondrocyte sheets for the reconstruction of osteochondral defects in rabbits

Cartilaginous extracellular matrix (ECM) materials derived from decellularized native articular cartilage are widely used in cartilage regeneration. However, it is difficult for endogenous cells to migrate into ECM derived from native cartilage owing to its nonporous structure and dense nature. Moreover, current decellularization approaches frequently lead to architectural breakdown and potential loss of surface composition of ECM. To solve this problem, we aimed to establish a novel biological ECM scaffold from chondrocyte sheets for cartilage regeneration. We cultured chondrocytes harvested from the auricular cartilage of 4-week-old New Zealand rabbits and enabled them to form cell sheets. These sheets were decellularized using sodium dodecyl sulfate (SDS) with three different concentrations, namely, 1%, 5%, and 10%, followed by 1% Triton X-100 and deoxyribonuclease enzyme solution. In vitro microstructural examination and mechanical tests demonstrated that 1% SDS not only removed chondrocytes completely but also maintained the native architecture and composition of ECM, thus avoiding the use of high-concentration SDS. Application of decellularized chondrocyte sheets for osteochondral defects in rabbits resulted in substantial host remodeling and variant regeneration of osteochondral tissues. One percent SDS-treated decellularized chondrocyte sheets contributed to the superior reconstruction of osteochondral defects as compared with 5% and 10% SDS groups, which includes vascularized subchondral bone, articular cartilage with adequate thickness, and integration with host tissues. Furthermore, ECM from 1% SDS significantly increased the migrating potential of bone marrow mesenchymal stem cells (BMSCs) in vitro. RT-PCR and western blot also revealed that ECM increased the expression of SOX-9 in BMSCs, whereas it decreased COL-X expression. In conclusion, our results suggested that the chondrocyte sheets decellularized with 1% SDS preserved the integrity and bioactivity, which favored cell recruitment and enabled osteochondral regeneration in the knee joints of rabbits, thus offering a promising approach for articular cartilage reconstruction without cell transplantation. Statement of SignificanceAlthough biological extracellular matrix (ECM) derived from decellularized native cartilage has been widely used in cartilage regeneration, it is difficult for endogenous cells to migrate into ECM owing to its dense nature. Moreover, current decellularization approaches lead to architectural breakdown of ECM. This study established a novel biological ECM from decellularized chondrocyte sheets for cartilage regeneration. Our results suggested that cartilaginous ECM favored cell recruitment and enabled osteochondral regeneration in rabbits, thus offering a promising approach for articular cartilage reconstruction without cell transplantation. SDS 1% adequately decellularized the chondrocytes in cell sheets, whereas it maintained the native architecture and composition of ECM, thereby avoiding the use of high-concentration SDS and providing a new way to acquire cartilaginous ECM.

Anionic surfactant modification of activated carbon for enhancing adsorption of ammonium ion from aqueous solution

This study investigates the effect of anionic surfactant modification on activated carbon (AC) to enhance the adsorption of ammonium ion in aqueous solution. Sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS) or sodium octanoate (SO) was used for the modification. At the initial aqueous concentration of 55 mg NH4-N/L and the adsorbent dose of 50 g/L, the SDS-modified AC showed the highest ammonium removal efficiency of 82% among the modified ACs studied. The hydrophobic group of SDS was strongly attached to AC showing almost negligible desorption after the modification. At the same time, the sulfate functional group of SDS provided ion exchange sites favorable for the ammonium ion adsorption. By maximizing SDS loading to the AC, ammonium removal efficiency can further be improved (5% increase). When Na+, K+ or Ca2+ coexisted in the ammonium solution at the concentration of 55 mg/L, the inhibition effect of these cations on ammonium removal efficiency was negligible (<5%). This study shows the potential of anionic surfactant-modified ACs as the excellent adsorbents for ammonium removal from water.

Aster glehni Extract Containing Caffeoylquinic Compounds Protects Human Keratinocytes through the TRPV4-PPARδ-AMPK Pathway.

Aster glehni (AG) has been used in cooking and as a medicine to treat various diseases for over hundreds of years in Korea. To speculate the protective effects of AG on skin barrier, we estimated the protein levels of biomarkers related to skin barrier protection in human keratinocytes, HaCaT cells treated with sodium dodecyl sulfate (SDS), or 2,4-dinitrochlorobenzene (DNCB). The protein levels for keratin, involucrin, defensin, tumor necrosis factor alpha (TNFα), peroxisome proliferator-activated receptor delta (PPARδ), 5′ adenosine monophosphate-activated protein kinase (AMPK), serine palmitoyltransferase long chain base subunit 2 (SPTLC2), and transient receptor potential cation channel subfamily V member 4 (TRPV4) were evaluated using western blotting or immunocytochemistry in HaCaT cells. AG extract increased the protein levels of PPARδ, phosphorylated AMPK, SPTLC2, keratin, involucrin, and defensin compared to the SDS or DNCB control group. However, TNFα expression increased by SDS or DNCB was decreased with AG extract. The order of action of each regulatory biomarker in AG pathway was identified TRPV4→PPARδ→AMPK from antagonist and siRNA treatment studies. AG can ameliorate the injury of keratinocytes caused by SDS or DNCB through the sequential regulation of TRPV4→PPARδ→AMPK pathway.

Methane Hydrate Formation Promoted by −SO3–-coated Graphene Oxide Nanosheets

Sodium dodecyl sulfate (SDS) has been reported as the most efficient kinetic promoter for hydrate-based natural gas storage and transportation; however, the foam generation during hydrate dissociation is a serious problem. In this work, we grafted the −SO3– group (similar as the hydrophilic group of SDS) on nanosheets of graphene oxide (GO) to prepare −SO3–-coated GO nanosheets (sulfonate graphene oxide, SGO), which were then used to promote methane hydrate formation. For comparison, graphene (GP) and GO were also prepared and used as kinetic promoters for methane hydrate formation. Among SGO, GP, and GO, SGO produced the best promotion, which at concentrations of 0.25, 0.5, 0.75 g/L resulted in methane hydrate formation finished within 208.7 ± 26.6, 242.3 ± 97.6, and 312 ± 135.5 min, respectively, with storage capacities reaching 139.7 ± 4.7, 143.3 ± 6.1, and 143.9 ± 7.2 v/v, respectively. Furthermore, −SO3–-coated nanosheets of SGO even produced better promotion to methane hydrate formation compared wit...

Green synthesis of gold nanoparticles reduced and stabilized by sodium glutamate and sodium dodecyl sulfate

The Turkevich method has been used for many years in the synthesis of gold nanoparticles. Lately, the use of plant extracts and amino acids has been reported, which is valuable in the field of biotechnology and biomedicine. The AuNPs was synthesized from the reduction of HAuCl4 3H2O by sodium glutamate and stabilized with sodium dodecyl sulfate. The optimum concentrations for sodium glutamate and sodium dodecyl sulfate in the synthesis process were determined. The characteristics of the synthesized AuNPs was analysed through UV–Vis Spectroscopy and SEM. The AuNPs have spherical shape with a mean diameter of approximately 21.62 ± 4.39 nm and is well dispersed. FTIR analysis of the AuNPs reflected that the sulfate head group of sodium dodecyl sulfate is adsorbed at the surface of the AuNPs. Thus, we report herein the synthesis of AuNPs using sodium glutamate and sodium dodecyl sulfate.

Effects of Detergent-Based Protocols on Decellularization of Corneas With Sclerocorneal Limbus. Evaluation of Regional Differences.

In this work, we decellularized whole porcine corneas including the sclerocorneal limbus (SCL) and we evaluated regional differences in order to identify an efficient method to decellularize whole corneas for future clinical use. We analyzed the efficiency of four decellularization protocols based on benzalkonium chloride (BAK), Igepal, sodium dodecyl sulfate (SDS), and Triton X-100 detergents on whole porcine corneas. Results showed that the decellularization efficiency of most protocols was low, with the specific protocol resulting in more efficient levels of decellularization being 0.1% SDS for 48 hours, especially in the medium and posterior cornea regions. A significant correlation was found between the decellularization efficiency and the concentration of agent used (P = 0.0174; r = 0.1540), but not for the incubation time (P > 0.05). The analysis of cornea components preservation demonstrated that all protocols were able to preserve the integrity of the Bowman's layer and Descemet's membrane. Although the collagen structure was partially altered, the global decellularization groups showing highest preservation of the ECM collagen contents and orientation were Igepal and SDS, with differences among the three regions of the cornea. All global groups showed high levels of proteoglycan and glycoprotein preservation after decellularization, with the best results were found in the SDS group followed by the Igepal group. These results suggest that very powerful protocols are necessary for whole-cornea decellularization. For the generation of lamelar corneas for clinical use, decellularization regional differences should be taken into account. Decellularized whole corneas may be potential therapeutic agents for lamelar keratoplasty.