Membrane Surface Research Articles

Photo-responsive anti-fouling polyzwitterionic brushes: a mesoscopic simulation.

The antifouling effects of a toothbrush-shaped photo-responsive polyzwitterionic membrane were studied via dissipative particle dynamics simulations in this work. The results reveal that the membrane modified by spiropyran methacrylate brushes displays photo-switchable and antifouling capability due to the photo-induced ring-opening reaction. Namely, surface morphology and hydrophilicity change in response to visible or UV light irradiation, which can be observed visually by protein adsorption and desorption. Further study indicates that: (1) brush-modification density can influence the structure and properties of the membrane. With low modification density, systems cannot establish an intact selective layer, which hinders the antifouling ability; as the modification density increases, the intact selective layer can be formed, which is conducive to the expression of photo-responsiveness and antifouling capability. (2) Factors of toothbrush-hair length and grafting ratio can influence the establishment of a light-responsive surface: as the grafting ratio and toothbrush-hair length increase, the light-responsive surface is gradually formed, meanwhile, the antifouling ability can be continuously reinforced under UV light irradiation. (3) As the brushes switch into a zwitterionic merocyanine state under UV exposure, the selective layer swelling becomes stronger than that with a hydrophobic spiropyran state under visible exposure. This is owing to the enhanced interaction between zwitterionic brushes and water, which is the root of the antifouling effect. The present work is expected to provide some guidelines for the design and development of novel antifouling membrane surfaces.

Tailor-Made Heterocharged Covalent Organic Framework Membrane for Efficient Ion Separation.

Pore size sieving, Donnan exclusion, and their combined effects seriously affect ion separation of membrane processes. However, traditional polymer-based membranes face some challenges in precisely controlling both charge distribution and pore size on the membrane surface, which hinders the ion separation performance, such as heavy metal ion removal. Herein, the heterocharged covalent organic framework (COF) membrane is reported by assembling two kinds of ionic COF nanosheets with opposite charges and different pore sizes. By manipulating the stacking quantity and sequence of two kinds of nanosheets, the impact of membrane surface charge and pore size on the separation performance of monovalent and multivalent ions is investigated. For the separation of anions, the effect of pore size sieving is dominant, while for the separation of cations, the effect of Donnan exclusion is dominant. The heterocharged TpEBr/TpPa-SO3H membrane with a positively charged upper layer and a negatively charged bottom layer exhibits excellent rejection of multivalent anions and cations (Ni2+, Cd2+, Cr2+, CrO4 2-, SeO3 2-, etc). The strategy provides not only high-performance COF membranes for ion separation but also an inspiration for the engineering of heterocharged membranes.

Endoplasmic reticulum stress regulates apoptosis and chemotherapeutic via enhancing TNFRSF10B recycling to the cell membrane in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most common malignant tumor in China. The expression and cell surface levels of TNF receptor superfamily member 10B (TNFRSF10B) are associated with apoptosis and chemotherapy. However, the precise molecular mechanisms that govern the regulation of TNFRSF10B remain unclear. RNA-Seq data related to TNBC chemotherapy resistance were acquired from the GEO database. The mRNA and protein levels of TNFRSF10B were detected using RT-PCR and Western blotting, respectively. Cell Counting Kit-8 (CCK-8) and colony formation assays were used to detect cell proliferation. Annexin V/7-AAD staining was used to evaluate apoptosis. The cell membrane TNFRSF10B was analyzed by Western blotting and immunofluorescence. Inducers and inhibitors of endoplasmic reticulum stress (ERS) were used to assess the effect of ERS on TNFRSF10B localization. TNFRSF10B expression was downregulated in TNBC and was associated with prognosis. TNFRSF10B overexpression inhibits the growth of TNBC both in vivo and in vitro and can partially counteract chemotherapy resistance. ERS activation in TNBC promotes the expression of TNFRSF10B, leading to its enrichment on the cell membrane surface, thereby activating the apoptotic pathways. ERS regulates the expression and subcellular localization of TNFRSF10B in TNBC cells. They synergistically affect anti-apoptosis and chemotherapy resistance in TNBC cells.

U(VI) mitigation via forward osmosis: elucidation of retention mechanisms and co-ion effects

Uranium (U) is a chemical and radioactive toxic contaminant affecting many groundwater systems. The focus of this study was to evaluate the suitability of forward osmosis (FO) for uranium rejection from contaminated groundwater under field-relevant conditions. Laboratory experiments with aqueous solution containing uranium were performed with FO membrane to understand the uranium rejection mechanism under varied pH, draw solution concentration, and presence of co-ions. Further, experiments were performed with U-contaminated field groundwater. Results of the hydrogeochemcial modelling using PHREEQC indicated that the rejection mechanism of uranium was highly dependent on aqueous speciation. Uranium rejection was maximum at alkaline pH with ca. 99% rejection due to charge-based interactions between membrane and dominant uranyl complexes. The results of the co-ion study indicated that nitrate and phosphate ions decrease uranium rejection. Whereas, bicarbonates, calcium, and magnesium ions concentrated uranium in feed solution. Further, the uranium adsorption onto the membrane surface primarily depended on pH of the aqueous solution with maximum adsorption at pH 5.5. Our results show that the World Health Organization’s drinking water guideline value of 30 μgL−1 for U could be achieved via FO process in field groundwater containing low dissolved solids.

An Innovative Surface Modification Technique for Antifouling Polyamide Nanofiltration Membranes.

In this study, we developed a novel surface coating technique to modify the surface chemistry of thin film composite (TFC) nanofiltration (NF) membranes, aiming to mitigate organic fouling while maintaining the membrane's permselectivity. We formed a spot-like polyester (PE) coating on top of a polyamide (PA) TFC membrane using mist-based interfacial polymerization. This process involved exposing the membrane surface to tiny droplets carrying different concentrations of sulfonated kraft lignin (SKL, 3, 5, and 7 wt %) and trimesoyl chloride (TMC, 0.2 wt %). The main advantages of this surface coating technique are minimal solvent consumption (less than 0.05 mL/cm2) and precise control over interfacial polymerization. Zeta potential measurements of the coated membranes exhibited enhancements in negative charge compared to the control membrane. This enhancement is attributed to the unreacted carboxyl functional groups of the SKL and TMC monomers, as well as the presence of sulfonate groups (SO3) in the structure of SKL. AFM results showed a notable decrease in membrane surface roughness after polyester coating due to the slower diffusion of SKL to the interface and a milder reaction with TMC. In terms of fouling resistance, the membrane coated with a polyester composed of 7 wt % SKL showed a 90% flux recovery ratio (FRR) during Bovine Serum Albumin (BSA) filtration, showing a 15% improvement compared to the control membrane (PA). PE-coated membranes provided stable separation performance over 40 h of filtration. The sodium chloride rejection and water flux displayed minimal variations, indicating the robustness of the coating layer. The final section of the presented study focuses on assessing the feasibility of scaling up and the cost-effectiveness of the proposed technique. The demonstrated ease of scalability and a notable reduction in chemical consumption establish this method as a viable, environmentally friendly, and sustainable solution for surface modification.

Development and life cycle assessment (LCA) of super-oleophobic (under water) and super-hydrophilic (in-air) mesh membrane for oily water treatment

This paper reports the fabrication, characterization, and environmental impact analysis of a super-oleophobic (under water) and super-hydrophilic mesh membrane for oily water treatment. In order to prepare mesh membrane, Titania nanoparticles (NPs) were spray coated on mesh stainless steel followed by calcination at 500 °C. After that, the Titania-coated mesh membrane was characterized using contact angle goniometry (CA), XRD, FE-SEM, EDX and elemental mapping. The FE-SEM, EDX, elemental mapping and XRD results confirmed that the Titania NPs were successfully coated on the surface of mesh membrane. CA results demonstrated that the prepared mesh membrane is super-hydrophilic and super-oleo phobic under water conditions, making it suitable for oil/water separation. Subsequently, life cycle assessment (LCA) was performed to determine the environmental impacts of Titania NPs-coated mesh membrane fabrication process. LCA results indicate that electricity and nitrogen contributed the most toward the eighteen environmental impact categories considered for this study.

Construction of PEO@g-C3N4 supported ionic liquid membrane with interactive network structure for enhanced carbon capture efficiency

Polyethylene oxide (PEO) shows a high CO2-philic due to its dipolar-quadrupolar interaction with CO2 molecules. As a result, it is an excellent candidate for gas separation applications, yet it faces problems such as crystallization and low permeance. Herein, we show a versatile strategy to enhance gas permeation fluxes, which is mainly achieved by hindering the crystallization of PEO and the stacking of nanosheets. Specifically, graphite-like phase carbon nitride (g-C3N4) nanosheets are introduced and interaction networks (PGCN) are constructed by taking full advantage of the dipole-level quadrupole moment interactions between the ether-oxygen groups contained in PEO and CO2. In order to compensate the membrane surface defects for enhancing gas selectivity, we used the suspension coating method to create a PEO@g-C3N4 supported ionic liquid membrane (PGCN/ILX SILM) by coating IL on the surface of membrane. The results show that, when the IL concentration is 30 wt%, the PGCN/IL30 % membrane separates CO2/N2 with a CO2 permeance of 1396 GPU and an optimal selectivity of 58. While overcoming the “Trade-off” effect, it has demonstrated good thermal stability and long-term stable operation for 72 h. The development of this work will generate solutions for overcoming PEO crystallization and achieving efficient CO2 capture.

Incorporation of composite metal-PVP derived carbon membranes for the percrystallisation of salt water

In this research using supported metal‑carbon membranes in a membrane percrystallisation application, we investigated the influence of metal ions on the formation of carbon during carbon membrane synthesis by combining polyvinylpyrrolidone (PVP) with various metal compounds, including zinc, potassium, barium, sodium, magnesium, calcium, and strontium, through calcination at 700 °C in a nitrogen atmosphere for the first time. These carbon membranes were then subjected to continuous percrystallisation experiments to produce dry salt crystals from salt solutions. The feed solution (3.5, 10, 20 wt% of salt) were used at 30, 50, and 70 °C for the performance evaluation. Intriguingly, the addition of metal elements to the PVP solution resulted in an enhancement in the total pore volume and surface area of the resulting carbon membranes. The PVP-Zn precursor exhibited the highest increase with a maximum improvement of 99 fold. Moreover, when compared to the PVP membranes alone, the composite membranes also exhibited higher fluxes. Among the tested composite carbon membranes, PVP-Ca, PVP-Zn, and PVP-Mg demonstrated the highest flux values, reaching an impressive 55 kg.m−2.h−1. Additionally, these membranes exhibited self-elimination, where salt was effectively removed from the membrane surface during percrystallisation testing. Thus, these membranes have the potential to be employed in desalination applications.

Integration of CaO2/Fe2+ and ultrafiltration acts as multiple-workfunctions pretreatment for seawater desalination during harmful algal blooms

This study employed calcium peroxide/ferrous iron (CaO2/Fe2+) as an innovative pretreatment strategy for seawater reverse osmosis (SWRO) operation during harmful algae blooms (HABs). CaO2/Fe2+ showed improved coagulation performance compared to conventional coagulation (Fe3+ coagulant). The dynamic dominance of foulants between micro-particles and algal organic matters (AOMs), due to the different dosages of CaO2/Fe2+, was found to be crucial in reducing ultrafiltration (UF) fouling. As a result, the optimal dosage of 0.05 mM/0.1 mM of CaO2/Fe2+ achieved a higher reduction of 71.6 % of modified fouling index (MFI) compared to conventional coagulation (38.1 % via 0.1 mM Fe3+). Specifically, CaO2/Fe2+ demonstrated a greater capacity to remove micro-particles across size ranges of 1–5 μm and various AOMs (i.e., biopolymer and humics) in algae-laden seawater compared to conventional coagulation. This resulted in reduced flux decline and less accumulation of algal cells, proteinaceous substances and humics on membrane surfaces, which were validated through Optical-Photothermal Infrared Spectromicroscopy (O-PTIR) with sub-micron resolution. Additionally, CaO2/Fe2+ reduced dissolved Fe3+ in UF permeate, and generated combined chlorine simultaneously with disinfection effects on marine algae (evidenced by O-PTIR and Raman spectroscopy). Thus, it would reduce fouling of subsequent SWRO membranes. Overall, CaO2/Fe2+ presents a multiple-workfunctions pretreatment method for HAB mitigation in seawater desalination plants.

Applications of Titanium Dioxide (TiO2) Nanoparticles in Photocatalysis

Titanium dioxide nanoparticles (TiO2 NPs) are conspicuously preferred as photocatalyst among the transition metal oxide nanoparticles. It exhibited in three polymorphisms of steady state rutile phase while brookite and anatase sustaining in metastable phase. The mixed phases of anatase phase and rarely found brookite phase mostly preferred for the photodegradation applications. The economically affordable along with nontoxic nature on top of excellent opto-electronics and catalytic properties of TiO2 NPs are eminently favorable for the photocatalytic degradation of chemically complex structured numerous organic and inorganic dyes, phenol and phenol-based derivatives, passive microplastics as well as suspended matters, non-biodegradable cytostatic drugs, acetaminophen, pharmaceutical organic waste compounds in addition to water pollutants. The photocatalytic capability of these NPs enhanced by upgrading the structural and morphological nature by opting different synthesis techniques as well preparing the nanocomposites of TiO2 incorporation with other metals. The hydrothermally prepared polymeric membranes of polyvinylidene with TiO2 NPs effectively (more than 90%) removed 17 α–ethinylestradiol from the contaminated water compared to Diclofenac under Uv irradiation. As it fronting the issue of electrostatic repulsion to all other membranes surface. The grafted membrane recorded highest degradation efficiency of 95.4% and best reusability of 90% saturated at fifth recycle for Methylene Blue azo dye compared with blending and dip coating membranes. The TiO2 modified ultrafiltration membranes of Polyvinylidene Fluoride with Dopamine illustrated the 92.6% photocatalytic degradation of Sulfadiazine which is most hazardous and highly resistant to biodegradation. 100% degradation of phenol derivative by TiO2 NPs hybrid polymeric films in visible light irradiation. The degradation efficiency of heterogenous photocatalyst Carbon–TiO2 contained anatase and brookite phased for Methylene Blue dye was 100% while for Rhodamine–B higher than 99% in solar and more than 78% in LED light irradiation. The recent trends for improvisation of photocatalytic ability of TiO2 NPs to enhance the quality of water and hence the mankind are elaborated.

Hierarchical biocatalytic membranes embedded with trypsin–inorganic hybrid nanoflowers for effective β-lactoglobulin hydrolysis

β-lactoglobulin (β-LG) is a significant allergen in milk. Enzymatic hydrolysis of β-LG produces peptides with low allergenicity and improved functionality. The biocatalytic membranes combine enzyme function and membrane separation in one step, but is still challenging for proteolysis. Herein, the biocatalytic membranes embedded with trypsin-inorganic hybrid nanoflowers are developed by a facile and green method for β-LG hydrolysis. Ethylene vinyl alcohol copolymer (EVAL) nanofibers are fabricated as 3D scaffolding on the membrane surface and trypsin-copper phosphate nanoflowers are in-situ grown in the porous structure of membranes. The nanoflowers are uniformly entrapped in the EVAL nanofiber layer and preferentially grow in the EVAL nanofibers layer, leading to the hierarchical structure of membranes. The trypsin loading of the nanoflowers membrane is approximate to 282.1µg/cm2. Lower Michaelis-Menten constants Km prove the better affinity of Cu3(PO4)2-TR nanoflower membrane with substrates during filtration than that in static mode, even than free trypsin. The hierarchical structure of the membranes ensures both the enhanced trypsin-substrate contacts and low mass transfer resistance during the β-LG filtration. This work not only presents a novel concept of enzyme immobilized biocatalytic membranes, but also offers a sustainable solution for high-performance proteolysis.

Comparison of UV/PS and VUV/PS as ultrafiltration pretreatment: Performance, mechanisms, DBPs formation and toxicity assessment

Ultrafiltration (UF) is widely used in drinking water plants, nevertheless, it still encounters challenges stemming from inevitable membrane fouling caused by natural organic matter (NOM). Herein, this work applied VUV/PS as UF membrane pretreatment and used UV/PS for comparison. VUV/PS system exhibited superior ability in removing NOM compared to UV/PS system. HO and SO4− played crucial roles in the degradation. [SO4−]ss was notably higher than [HO]ss in the systems, yet HO was of greater significance. [HO]ss and [SO4−]ss in the VUV/PS process were remarkably higher than those in the UV/PS process, due to the function of 185 nm photons. VUV/PS pretreatment basically recovered flux and effectively reduced fouling resistance, with better performance than UV/PS. Fouling mechanism was dominated by multiple mechanisms after UV/PS pretreatment, whereas it was transformed into pore blockage after VUV/PS pretreatment. Moreover, the UF effluent quality after VUV/PS pretreatment outperformed that of UV/PS but fell short of that without pretreatment, possibly due to the generation of abundant low MW substances under the action of HO and SO4−. After chlorine disinfection, UV/PS and VUV/PS pretreatments increased the DBPs production and cytotoxicity. Specifically, oxidant PS affected the membrane surface morphology and fouling behaviors, and had no obvious effect on interception performance and mechanical properties. In actual water treatment, VUV/PS and UV/PS pretreatments exhibited excellent performance in alleviating membrane fouling, improving water quality, and reducing DBPs formation and acute toxicity.

Alleviation of RO Membrane Fouling in Wastewater Reclamation Plants Using an Enhanced Acid-Base Chemical Cleaning Method

Membrane fouling has always been a critical constraint in the operation of the reverse osmosis (RO) process, and chemical cleaning is essential for mitigating membrane fouling and ensuring smooth operation of the membrane system. This paper presents an optimized chemical cleaning method for efficient cleaning of RO membranes in full-scale applications. Compared to the regular cleaning method (cleaning with 0.1% NaOH+1% EDTA+0.025% SDBS followed by 0.2% HCl), the optimized cleaning method improves the cleaning efficiency by adding sodium chloride to the alkaline cleaning solution and citric acid to the acid cleaning solution. Notably, the membrane flux recovery rate with the optimized cleaning method is 45.74%, and it improves the cleaning efficiency by 1.65 times compared to the regular cleaning method. Additionally, the optimized cleaning method removes 30.46% of the total foulants (organic and inorganic), which is 2.11 times higher than the regular cleaning method. The removal of inorganic ions such as Fe, Ca, and Mg is significantly improved with the optimized cleaning method. For organic matter removal, the optimized cleaning method effectively removes more polysaccharides, proteins, and microbial metabolites by disrupting the complex structure of organic matter. Furthermore, it also changes the microbial community structure on the RO membrane surface by eliminating microorganisms that cannot withstand strong acids, bases, and high salt environments. However, Mycobacterium can adapt to these harsh conditions and shows a relative abundance of up to 84.13% after cleaning. Overall, our results provide a new chemical cleaning method for RO membranes in full-scale applications. This method effectively removes membrane foulants and enhances the understanding of the removal characteristics of foulants on RO membrane surfaces by chemical cleaning.

Plasma-aerosol-assisted interface engineering of nanofiltration membranes to improve removal of organic pollutants from water

Membrane surface functionalization has shown great potential in improving the removal of organic pollutants from water by nanofiltration (NF). However, conventional surface modification methods rely on hazardous chemical solutions and produce large amounts of wastewater, which is contrary to the original purpose of wastewater remediation and the current high demand for environmental sustainability. Herein, we demonstrate a solvent-free and scalable method enabled by an emerging aerosol-assisted plasma deposition process for surface functionalization of NF membranes to improve the removal of organic pollutants from water. We first investigate the physicochemical properties of the aerosol-assisted plasma deposited (3-aminopropyl)triethoxysilane (AAPD-APTES) and 2-hydroxyethyl methacrylate (AAPD-HEMA) coatings on commercial NF270 membranes by different surface characterization techniques. Then, we examine the associated membranes’ performance in removing conventional organic pollutants (phenol) and emerging micropollutants (diuron). Compared to the untreated NF270 membranes (2.9% for phenol and 22.0% for diuron), AAPD-APTES-modified NF270 membranes have the highest rejection efficiency toward both phenol (68.5%) and diuron (49.1%), whereas AAPD-HEMA coated membranes show good selectivity behavior with a high rejection efficiency for diuron (43.6%) but a relatively low efficiency for phenol (6.2%). Both plasma polymer-coated membranes are effective in removing organic contaminants mainly due to the plasma-produced dense surface coatings. Overall, this study offers a comprehensive eco-friendly and scalable strategy for NF membrane surface functionalization, which can not only improve the NF performance in wastewater remediation but also reduce the production of wastewater in the surface functionalization process.

Effects of functional groups of polyfluoroalkyl substances on their removal by nanofiltration

Determining the reliability of nanofiltration (NF) membranes for the removal of contaminants of emerging concern, including polyfluoroalkyl substances (PFASs), pharmaceuticals, and personal care products (PPCPs), is important for ensuring drinking water safety. This study aimed to clarify the factors that influence the removal of nine major PFASs during submerged NF treatment via extrapolation based on the factors that influence PPCP removal. The rejection of nine PFASs in ultra-filtered dam water by a polypiperazine-amide (NF270) membrane increased from 71% to 94% at a low permeate flux of 5 L/m2 h as the PFAS molecular dimensions increased. PFASs with a carboxylic acid (-CO2H) were rejected to a greater extent than PFASs with a sulfo group (-SO3H). Further, negatively charged PFASs or PPCPs were rejected to a greater extent than uncharged and positively charged PPCPs. Our findings suggest that the rejection of PFASs can vary because of the (i) clearance distance between the PFASs’ molecular dimensions and NF membrane pore diameter and (ii) intensity of electrostatic repulsion between the PFASs’ functional groups and NF membrane surface. Our study indicates that submerged NF can achieve high PFAS rejection; however, variation in rejection among PFASs can become more prominent owing to a low permeate flux.

Highly adhesive bioinspired membrane for efficient oil/water separation by optimization of synergistic effects of hierarchical structure and superhydrophobic modification

Superwetting membranes have good prospective for treatment of oil-containing wastewaters. However, development of highly adhesive superhydrophobic membranes with efficient oil-water separation performance remains a great challenge that needs to be addressed urgently. Herein, highly adhesive membrane surface with hierarchical structure were fabricated by in-situ TEOS hydrolysis and fluorinated modification. The interface bonding force between polyvinylidene fluoride (PVDF) and silica nanoparticles (SiO2 NPs) was increased through the dopamine self-polymerization and adhesion. The hierarchical structure was obtained by simultaneously adjusting TEOS and ammonia contents. The three-dimensional hierarchical membrane structure which is similar to that of a rose petal was shown by SEM analysis. The obtained membrane showed a water contact angle of 158 ± 2°, while the oil contact angle approaches 0°. In-situ grown multi-scale SiO2 NPs, perfluorooctyltriethoxysilane (FAS) brushes and dopamine can form a stable hierarchical surface which sustained superhydrophobicity/superoleophilicity when immersed in aqueous solutions at different pH values. Meanwhile, FAS brushes can serve as steric obstacles to efficiently repel water droplets during oil/water separation. The fabricated membrane possesses a high permeation flux and excellent separation properties (> 98%). In addition, this highly adhesive coating modification and hierarchical design can be widely applied on the surfaces of different materials, giving an attractive potential application prospect, such as oil/water separation, antifouling surface, and superwetting materials.

Kirigami enabled reconfigurable three-dimensional evaporator arrays for dynamic solar tracking and high efficiency desalination.

A kirigami-engineered composite hydrogel membrane is exploited for the construction of three dimensional (3D) solar-tracking evaporator arrays with outstanding evaporation performance and salt tolerance. The hybrid nanofiber network in the hydrogel membrane offers favorable water transport dynamics combined with excellent structural robustness, which are beneficial for the engineering of 3D dynamic structures. Periodic triangular cuts patterned into the membrane allow formation and reconfiguration of 3D conical arrays controlled by uniaxial stretching. With these structures, the tilt angles of the membrane surface are actively tuned to follow the solar trajectory, leading to a solar evaporation rate ~80% higher than that of static planar devices. Furthermore, the tapered 3D flaps and their micro-structured surfaces are capable of localized salt crystallization for prolonged solar desalination, enabling a stable evaporation rate of 3.4 kg m-2 hour-1 even in saturated brine. This versatile design may facilitate the implementation of solar evaporators for desalination and provide inspirations for other soft functional devices with dynamic 3D configurations.

ADAM10 Alleviates Hypoxia/Reoxygenation-Induced Cardiomyocyte Injury by Activating the Notch Signaling Pathway.

The occurrence of myocardial ischemia/reperfusion injury is commonly observed during cardiac surgery; however, there remains a dearth of effective therapeutic strategies to mitigate this injury. The a disintegrin and metallopeptidase domain 10 (ADAM10) is a transmembrane protein anchored on the cell membrane surface, and its precise mechanism of action in myocardial ischemia/reperfusion injury remains incompletely understood. This study aims to investigate the impact of ADAM10 on cardiomyocyte injury induced by hypoxia/reoxygenation (H/R) and elucidate the underlying mechanisms. The ADAM10 overexpression plasmid was transfected into H9c2 cells, which were subsequently treated with the Notch signaling pathway inhibitor DAPT and cultured under H/R conditions. Cell proliferation activity was assessed using the CCK-8 assay. The levels of LDH, SOD, and MDA were quantified through colorimetric analysis. The levels of ROS and the rate of apoptosis were measured using flow cytometry. The morphological changes in the nucleus of H9c2 cells were observed by employing Hoechst 33258 staining. The mRNA expression levels of ADAM10, Notch1, NICD, and Hes1 in H9c2 cells were determined using qRT-PCR. The expressions of Notch signaling pathway and apoptosis-related proteins were analyzed by Western blot. Overexpression of ADAM10 provided protection to H9c2 cells against injury induced by H/R, leading to an increase in SOD levels and alleviation of oxidative stress caused by the accumulation of ROS and the decrease of SOD activity. Meanwhile, overexpression of ADAM10 inhibited apoptosis in H9c2 cells exposed to H/R by regulating the expression of apoptosis-related proteins, such as Bax, Bcl-2 and Cleaved-caspase-3. Additionally, overexpression of ADAM10 facilitated the activation of the Notch1 signaling pathway in H9c2 cells exposed to H/R by upregulating the protein expression of Notch1, NICD, and Hes1. However, the protective effect of ADAM10 on H/R-induced H9c2 cells was partially reversed by DAPT. Our findings demonstrate that ADAM10 exerts protective effects in H/R-induced H9c2 cells by suppressing oxidative stress and apoptosis via the activation of the Notch signaling pathway.

The role of GPD1L, a sodium channel interacting gene, in the pathogenesis of Brugada Syndrome.

Brugada Syndrome (BrS) is an inherited arrhythmia syndrome in which mutations in the cardiac sodium channel SCN5A (NaV1.5) account for approximately 20% of cases. Mutations in sodium channel-modifying genes may account for additional BrS cases, though BrS may be polygenic given common SNPs associated with BrS have been identified. Recent analysis, however, has suggested that SCN5A should be regarded as the sole monogenic cause of BrS. We sought to re-assess the genetic underpinnings of BrS in a large mutligenerational family with a putative mutation in GPD1L that affects surface membrane expression of NaV1.5 in vitro. Fine linkage mapping was performed in the family using the Illumina Global Screening Array. Whole exome sequencing of the proband was performed to identify rare variants and mutations, and Sanger sequencing was used to assay previously-reported risk single nucleotide polymorphsims (SNPs) for BrS. Linkage analysis decreased the size of the previously-reported microsatellite linkage region to approximately 3 Mb. GPD1L-A280V was the only coding non-synonymous variation present at less than 1% allele frequency in the proband within the linkage region. No rare non-synonymous variants were present outside the linkage area in affected individuals in genes associated with BrS. Risk SNPs known to predispose to BrS were overrepresented in affected members of the family. Together, our data suggest GPD1L-A280V remains the most likely cause of BrS in this large multigenerational family. While care should be taken in interpreting variant pathogenicity given the genetic uncertainty of BrS, our data support inclusion of other putative BrS genes in clinical genetic panels.

Size- and Shape-Dependent Interactions of Lipid-Coated Silver Nanoparticles: An Improved Mechanistic Understanding through Model Cell Membranes and In Vivo Toxicity.

The widespread use of silver nanoparticles (AgNPs) in various applications and industries has brought to light the need for understanding the complex relationship between the physicochemical properties (shape, size, charge, and surface chemistry) of AgNPs that affect their ability to enter cells and cause toxicity. To evaluate their toxicological outcomes, this study systematically analyzed a series of homogeneous hybrid lipid-coated AgNPs spanning sizes from 5 to 100 nm with diverse shapes (spheres, triangles, and cubes). The hybrid lipid membrane comprises hydrogenated phosphatidylcholine (HPC), sodium oleate (SOA), and hexanethiol (HT), which shield the AgNP surface from surface oxidation and toxic Ag+ ion release to minimize its contribution to toxicity. To reduce any significant effects by surface chemistry, the HPC, SOA, and HT membrane composition ratio was kept constant, and the AgNPs were assessed using embryonic zebrafish (Danio rerio). While a direct comparison cannot be drawn due to the lack of complementary sizes below 40 nm for triangular plates and cubes due to synthetic challenges, significant mortality was observed for spherical AgNPs (AgNSs) of 5, 20, 40, and 60 nm at 120 h postfertilization at concentrations ≥6 mg Ag/L. In contrast, the 10, 80, and 100 nm AgNSs, 40, 70, and 100 nm triangular plate AgNPs (AgNPLs), and 55, 75, and 100 nm cubic AgNPs (AgNCs) showed no significant mortality at 5 days postfertilization following exposure to AgNPs at concentrations up to 12 mg Ag/L. With constant surface chemistry on the AgNPs, size is the dominant factor driving toxicological responses, with smaller nanoparticles (5 to 60 nm) being the most toxic. Larger AgNSs, AgNCs, and AgNPLs from 75 to 100 nm do not show any evidence of toxicity. However, when closely examining sizes between 40 and 60 nm for AgNSs, AgNCs, and AgNPLs, there is evidence that discriminates shape as a driver of toxicity since sublethal responses generally were observed to follow a pattern, suggesting toxicity is most significant for AgNSs followed by AgNPLs and then AgNCs, which is the least toxic. Sum frequency generation vibrational spectroscopy showed that irrespective of size or shape, all hybrid lipid-coated AgNPs interact with membrane surfaces and "snorkel" between phases into the lipid monolayer with minimal energetic cost. These findings decisively demonstrate that not only smaller AgNPs but also the shape of the AgNPs influences their biological compatibility.