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1.
Nat Commun ; 14(1): 5364, 2023 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-37666808

RESUMO

Biological membrane channels mediate information exchange between cells and facilitate molecular recognition. While tuning the shape and function of membrane channels for precision molecular sensing via de-novo routes is complex, an even more significant challenge is interfacing membrane channels with electronic devices for signal readout, which results in low efficiency of information transfer - one of the major barriers to the continued development of high-performance bioelectronic devices. To this end, we integrate membrane spanning DNA nanopores with bioprotonic contacts to create programmable, modular, and efficient artificial ion-channel interfaces. Here we show that cholesterol modified DNA nanopores spontaneously and with remarkable affinity span the lipid bilayer formed over the planar bio-protonic electrode surface and mediate proton transport across the bilayer. Using the ability to easily modify DNA nanostructures, we illustrate that this bioprotonic device can be programmed for electronic recognition of biomolecular signals such as presence of Streptavidin and the cardiac biomarker B-type natriuretic peptide, without modifying the biomolecules. We anticipate this robust interface will allow facile electronic measurement and quantification of biomolecules in a multiplexed manner.


Assuntos
Membranas Artificiais , Nanoporos , Bicamadas Lipídicas , Membrana Celular , DNA
2.
Int J Mol Sci ; 24(16)2023 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-37629177

RESUMO

The intricate voltage regulation presented by lysenin channels reconstituted in artificial lipid membranes leads to a strong hysteresis in conductance, bistability, and memory. Prior investigations on lysenin channels indicate that the hysteresis is modulated by multivalent cations which are also capable of eliciting single-step conformational changes and transitions to stable closed or sub-conducting states. However, the influence on voltage regulation of Cu2+ ions, capable of completely closing the lysenin channels in a two-step process, was not sufficiently addressed. In this respect, we employed electrophysiology approaches to investigate the response of lysenin channels to variable voltage stimuli in the presence of small concentrations of Cu2+ ions. Our experimental results showed that the hysteretic behavior, recorded in response to variable voltage ramps, is accentuated in the presence of Cu2+ ions. Using simultaneous AC/DC stimulation, we were able to determine that Cu2+ prevents the reopening of channels previously closed by depolarizing potentials and the channels remain in the closed state even in the absence of a transmembrane voltage. In addition, we showed that Cu2+ addition reinstates the voltage gating and hysteretic behavior of lysenin channels reconstituted in neutral lipid membranes in which lysenin channels lose their voltage-regulating properties. In the presence of Cu2+ ions, lysenin not only regained the voltage gating but also behaved like a long-term molecular memory controlled by electrical potentials.


Assuntos
Eletrofisiologia Cardíaca , Eletricidade , Íons , Membranas Artificiais , Lipídeos
3.
J Hazard Mater ; 459: 132246, 2023 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-37557047

RESUMO

Osmotic membrane bioreactors (OMBRs) are considered a suitable technology for treating wastewater containing tetracycline due to their high rejection and biodegradation efficiency. However, the impact of membrane fouling layer (i.e., chemical composition, microbial composition, and formation) on the filtration and biodegradation of tetracycline is still unclear. Herein, the effects of draw solute concentration and type on the formation of a membrane fouling layer for tetracycline filtration and its relationship with microbial activity were investigated. The results showed that over 99% of tetracycline was retained on the feed side by membrane rejection, and the fouling layer played an important role in tetracycline filtration. Specifically, membrane foulants resulted in a more hydrophilic membrane facilitating tetracycline filtration, while the tetracycline-degrading genera from the fouled membrane promoted tetracycline degradation. The structure equation model showed that tetracycline filtration dominated by electrostatic repulsion between tetracycline and the fouled membrane was more important than tetracycline degradation for tetracycline removal (path coefficient of 0.655 vs. 0.395). This study provided insights into the combined effect of membrane foulants and microorganisms on tetracycline removal.


Assuntos
Antibacterianos , Membranas Artificiais , Águas Residuárias , Tetraciclina , Reatores Biológicos
4.
Int J Mol Sci ; 24(15)2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37569488

RESUMO

Olea europaea L. leaves contain a wide variety of pentacyclic triterpenes (TTPs). TTPs exhibit many pharmacological activities, including antihyperlipidemic effects. Metabolic alterations, such as dyslipidemia, are an established risk factor for hepatocellular carcinoma (HCC). Therefore, the use of TTPs in the adjunctive treatment of HCC has been proposed as a possible method for the management of HCC. However, TTPs are characterized by poor water solubility, permeability, and bioavailability. In this work, a microemulsion (ME) loading a TTP-enriched extract (EXT) was developed, to overcome these limits and obtain a formulation for oral administration. The extract-loaded microemulsion (ME-EXT) was fully characterized, assessing its chemical and physical parameters and release characteristics, and the stability was evaluated for two months of storage at 4 °C and 25 °C. PAMPA (parallel artificial membrane permeability assay) was used to evaluate the influence of the formulation on the intestinal passive permeability of the TTPs across an artificial membrane. Furthermore, human hepatocarcinoma (HepG2) cells were used as a cellular model to evaluate the effect of EXT and ME-EXT on de novo lipogenesis induced by elevated glucose levels. The effect was evaluated by detecting fatty acid synthase expression levels and intracellular lipid accumulation. ME-EXT resulted as homogeneous dispersed-phase droplets, with significantly increased EXT aqueous solubility. Physical and chemical analyses showed the high stability of the formulation over 2 months. The formulation realized a prolonged release of TTPs, and permeation studies demonstrated that the formulation improved their passive permeability. Furthermore, the EXT reduced the lipid accumulation in HepG2 cells by inhibiting de novo lipogenesis, and the ME-EXT formulation enhanced the inhibitory activity of EXT on intracellular lipid accumulation.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Olea , Triterpenos , Humanos , Triterpenos Pentacíclicos , Lipogênese , Células Hep G2 , Carcinoma Hepatocelular/tratamento farmacológico , Emulsões/química , Neoplasias Hepáticas/tratamento farmacológico , Triterpenos/farmacologia , Triterpenos/química , Membranas Artificiais , Folhas de Planta , Lipídeos
5.
Environ Sci Technol ; 57(32): 11863-11875, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37540002

RESUMO

Groundwater salinization is a problem affecting access to water in many world regions. Though desalination by conventional reverse osmosis (RO) can upgrade groundwater quality for drinking, its disadvantages include unmanaged brine discharge and accelerated groundwater depletion. Here, we propose a new approach combining RO, forward osmosis (FO), and halophyte cultivation, in which FO optimally adjusts the concentration of the RO reject brine for irrigation of Salicornia or Sarcocornia. The FO also re-uses wastewater, thus, reducing groundwater extraction and the wastewater effluent volume. To suit different groundwater salinities in the range 1-8 g/L, three practical designs are proposed and analyzed. Results include specific groundwater consumption (SGC), specific energy consumption (SEC), wastewater volume reduction, peak RO pressure, permeate water quality, efficiency of water resource utilization, and halophyte yield. Compared to conventional brackish water RO, the results show superior performance in almost all aspects. For example, SGC is reduced from 1.25 to 0.9 m3 per m3 of drinking water output and SEC is reduced from 0.79 to 0.70 kW h/m3 by a FO-RO-FO system treating groundwater of salinity 8 g/L. This system can produce 1.1 m3 of high-quality drinking water and up to 4.9 kg of edible halophyte per m3 of groundwater withdrawn.


Assuntos
Água Potável , Água Subterrânea , Purificação da Água , Águas Residuárias , Plantas Tolerantes a Sal , Purificação da Água/métodos , Membranas Artificiais
6.
Chemosphere ; 339: 139676, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37527740

RESUMO

The disintegration of anaerobic sludge and blockage of membrane pores has impeded the practical application of anaerobic membrane bioreactor (AnMBR) in treating methanolic wastewater. In this study, bioelectrochemical system (BES) was integrated into AnMBR to alleviate sludge dispersion and membrane fouling as well as enhance bioconversion of methanol. Bioelectrochemical regulation effect induced by BES enhanced methane production rate from 4.94 ± 0.52 to 5.39 ± 0.37 L/Lreactor/d by accelerating the enrichment of electroactive microorganisms and the agglomeration of anaerobic sludge via the adhesive and chemical bonding force. 16 S rRNA gene high-throughput sequencing demonstrated that bioelectrochemical stimulation had modified the metabolic pathways by regulating the key functional microbial communities. Methanogenesis via the common methylotrophic Methanomethylovorans was partially substituted by the hydrogenotrophic Candidatus_Methanofastidiosum, etc. The metabolic behaviors of methanol are bioelectrochemistry-dependent, and controlling external voltage is thus an effective strategy for ensuring robust electron transfer, low membrane fouling, and long-term process stability.


Assuntos
Metanol , Águas Residuárias , Esgotos/química , Anaerobiose , Biomassa , Metano/metabolismo , Reatores Biológicos , Eliminação de Resíduos Líquidos , Membranas Artificiais
7.
Environ Sci Pollut Res Int ; 30(42): 95875-95891, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37561306

RESUMO

The wastewater discharged from crude oil storage tanks (WCOST) contains high concentrations of salt and metal iron ions, and high chemical oxygen demand (COD). It belongs to "3-high" wastewater, which is difficult for purification. In this study, WCOST treatments were comparatively investigated via an advanced pretreatment and the traditional coagulation-microfiltration (CMF) processes. After WCOST was purified through the conventional CMF process, fouling occurred in the microfiltration (MF) membrane, which is rather harmful to the following reverse osmosis (RO) membrane unit, and the effluent featured high COD and UV254 values. The analysis confirmed that the MF fouling was due to the oxidation of ferrous ions, and the high COD and UV254 values were mainly attributable to the organic compounds with small molecular sizes, including aromatic-like and fulvic-like compounds. After the pretreatment of the advanced process consisting of aeration, manganese sand filtration, and activated carbon adsorption in combination with CMF process, the removal efficiencies of organic matter and total iron ions reached 97.3% and 99.8%, respectively. All the water indexes of the effluent, after treatment by the advanced multi-unit process, meet well the corresponding standard. The advanced pretreatment process reported herein displayed a great potential for alleviating the MF membrane fouling and enhanced the lifetime of the RO membrane system in the 3-high WCOST treatment.


Assuntos
Petróleo , Purificação da Água , Águas Residuárias , Eliminação de Resíduos Líquidos , Petróleo/análise , Filtração , Íons/análise , Ferro/análise , Osmose , Membranas Artificiais
8.
Water Res ; 243: 120428, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37536247

RESUMO

Although the autopsies of reverse osmosis (RO) membranes from full-scale, brackish water desalination plants identify the co-presence of silica and Ca-based minerals in scaling layers, minimal research exists on their formation process and mechanisms. Therefore, combined scaling by silica and either gypsum (non-alkaline) or amorphous calcium phosphate (ACP, alkaline) was investigated in this study for their distinctive impacts on membrane performance. The obtained results demonstrate that the coexistence of silica and Ca-based mineral salts in feedwaters significantly reduced water flux decline as compared to single type of Ca-based mineral salts. This antagonistic effect was primarily attributed to the silica-mediated alleviation of Ca-based mineral scaling. In the presence of silica, silica skins were immediately established around Ca-based mineral precipitates once they emerged. Sheathing by the siliceous skins hindered the aggregation and thus the morphological evolution of Ca-based mineral species. Unlike sulfate precipitates, ACP precipitates can induce the formation of dense and thick silica skins via an additional condensation reaction. Such a phenomenon rationalized the notion concerning a stronger mitigating effect of silica on ACP scaling than gypsum scaling. Meanwhile, coating by silica skins altered the surface chemistries of Ca-based mineral precipitates, which should be fully considered in regulating membrane surface properties for combined scaling control. Our findings advance the mechanistic understanding on combined mineral scaling of RO membranes, and may guide the appropriate design of membrane surface properties for scaling-resistant membrane tailored to brackish water desalination.


Assuntos
Dióxido de Silício , Purificação da Água , Cálcio , Sulfato de Cálcio , Sais , Purificação da Água/métodos , Osmose , Minerais , Águas Salinas , Membranas Artificiais
9.
Chemosphere ; 339: 139693, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37536541

RESUMO

Treating and reusing wastewater has become an essential aspect of water management worldwide. However, the increase in emerging pollutants such as polycyclic aromatic hydrocarbons (PAHs), which are presented in wastewater from various sources like industry, roads, and household waste, makes their removal difficult due to their low concentration, stability, and ability to combine with other organic substances. Therefore, treating a low load of wastewater is an attractive option. The study aimed to address membrane fouling in the submerged membrane bioreactor (SMBR) used for wastewater treatment. An aluminum electrocoagulation (EC) device was combined with SMBR as a pre-treatment to reduce fouling. The EC-SMBR process was compared with a conventional SMBR without EC, fed with real grey water. To prevent impeding biological growth, low voltage gradients were utilized in the EC deviceThe comparison was conducted over 60 days with constant transmembrane pressure and infinite solid retention time (SRT). In phase I, when the EC device was operated at a low voltage gradient (0.64 V/cm), no significant improvement in the pollutants removal was observed in terms of color, turbidity, and chemical oxygen demand (COD). Nevertheless, during phase II, a voltage gradient of 1.26 V/cm achieved up to 100%, 99.7%, 92%, 94.1%, and 96.5% removals in the EC-SMBR process in comparison with 95.1%, 95.4%, 85%, 91.7% and 74.2% removals in the SMBR process for turbidity, color, COD, ammonia nitrogen (NH3-N), total phosphorus (TP), respectively. SMBR showed better anionic surfactant (AS) removal than EC-SMBR. A voltage gradient of 0.64 V/cm in the EC unit significantly reduced fouling by 23.7%, while 1.26 V/cm showed inconsistent results. Accumulation of Al ions negatively affected membrane performance. Low voltage gradients in EC can control SMBR fouling if Al concentration is controlled. Future research should investigate EC-SMBR with constant membrane flux for large-scale applications, considering energy consumption and operating costs.


Assuntos
Poluentes Ambientais , Purificação da Água , Águas Residuárias , Eliminação de Resíduos Líquidos/métodos , Membranas Artificiais , Eletrocoagulação , Reatores Biológicos , Purificação da Água/métodos , Água/química
10.
Langmuir ; 39(36): 12590-12598, 2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37651551

RESUMO

Despite advancements in contemporary therapies, cardiovascular disease from atherosclerosis remains a leading cause of mortality worldwide. Supported lipid bilayers (SLBs) are membrane interfaces that can be constructed with varying lipid compositions. Herein, we use a solvent-assisted lipid bilayer (SALB) construction method to build SLB membranes with varying cholesterol compositions to create a lipid-sterol interface atop a piezoelectric sensor. These cholesterol-laden SLBs were utilized to investigate the mechanisms of various cholesterol-lowering drug molecules. Within a flow-cell, membranes with varying cholesterol content were exposed to cyclodextrins 2-hydroxypropyl-beta-cyclodextrin (HPßCD) and methyl-beta-cyclodextrin (MßCD). Quartz-crystal microgravimetry with dissipation monitoring (QCM-D) enabled the collection of in vitro, real-time changes in relative areal mass and dissipation. We define the cholesterol desorbing competency of a cyclodextrin species via measures of the rate of cholesterol removal, the rate of the transfer of membrane-bound cholesterol to drug-complexed cholesterol, and the binding strength of the drug to the cholesterol-ladened membrane. Desorption data revealed distinct cholesterol removal kinetics for each cyclodextrin while also supporting a model for the lipid-cholesterol-drug interface. We report that MßCD removes a quantity of cholesterol 1.61 times greater, with a speed 2.12 times greater, binding affinity to DOPC lipid interfaces 1.97 times greater, and rate of internal cholesterol transfer 3.41 times greater than HPßCD.


Assuntos
Ciclodextrinas , beta-Ciclodextrinas , Membranas Artificiais , 2-Hidroxipropil-beta-Ciclodextrina , Avaliação Pré-Clínica de Medicamentos , Bicamadas Lipídicas , Colesterol
11.
Water Sci Technol ; 88(2): 408-429, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37522442

RESUMO

As the population continues to grow, the preservation of the world's water resources is becoming a serious challenge. The seawater desalination process is considered a sustainable option for the future. The two most common technologies used in desalination are reverse osmosis (RO) and membrane distillation (MD). However, membrane fouling caused by the accumulation of contaminants on the membrane surface is an emerging and growing problem. A pre-treatment stage is required to reach optimal efficiency during the desalination process since this stage is crucial for a successful desalination process. In this regard, the development of new material-based composite membranes has the potential to upgrade the anti-fouling features of RO membranes thereby enhancing desalination efficiency due to their high permeability, hydrophilicity, selectivity mechanical strength, thermal stability, and anti-bacterial properties. The objective of this review is to present various techniques for seawater pre-treatment. The results of the use of several membrane types and methods of modification have also been discussed. The performance of composite membranes for seawater pre-treatment is defined and the future perspectives have been highlighted.


Assuntos
Membranas Artificiais , Purificação da Água , Osmose , Purificação da Água/métodos , Água do Mar , Permeabilidade
12.
Sci Adv ; 9(28): eadg6638, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37450594

RESUMO

Membrane technologies that enable the efficient purification of impaired water sources are needed to address growing water scarcity. However, state-of-the-art engineered membranes are constrained by a universal, deleterious trade-off where membranes with high water permeability lack selectivity. Current membranes also poorly remove low-molecular weight neutral solutes and are vulnerable to degradation from oxidants used in water treatment. We report a water desalination technology that uses applied pressure to drive vapor transport through membranes with an entrapped air layer. Since separation occurs due to a gas-liquid phase change, near-complete rejection of dissolved solutes including sodium chloride, boron, urea, and N-nitrosodimethylamine is observed. Membranes fabricated with sub-200-nm-thick air layers showed water permeabilities that exceed those of commercial membranes without sacrificing salt rejection. We also find the air-trapping membranes tolerate exposure to chlorine and ozone oxidants. The results advance our understanding of evaporation behavior and facilitate high-throughput ultraselective separations.


Assuntos
Destilação , Purificação da Água , Permeabilidade , Gases , Purificação da Água/métodos , Membranas Artificiais
13.
Compend Contin Educ Dent ; 44(7): 408-414, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37450679

RESUMO

Stabilization of the graft-membrane complex during guided bone regeneration is a critically important aspect of implant dentistry. Several articles in the dental literature have introduced the utilization of periosteal biting stabilization sutures, rather than fixation screws and pins, to stabilize a bioabsorbable collagen membrane. This article reviews the concept of stabilization using sutures in periodontal regeneration and describes an alternative method, the Ribroast technique™, to stabilize a bioabsorbable membrane, whereby single periosteal biting horizontal mattress sutures are placed along the length of the defect to achieve sufficient stabilization. Two cases are presented that highlight the utility of this technique. Guidelines and limitations for the use of periosteal biting sutures are also discussed along with considerations and protocols that may be useful for improving treatment outcomes.


Assuntos
Transplante Ósseo , Regeneração Tecidual Guiada Periodontal , Regeneração Tecidual Guiada Periodontal/métodos , Transplante Ósseo/métodos , Membranas Artificiais , Implantação Dentária Endóssea/métodos , Colágeno , Regeneração Óssea
14.
Water Sci Technol ; 88(1): 169-184, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37452541

RESUMO

Variations in transmembrane pressure and permeate flux are closely related to membrane fouling. In this study, a laboratory-scale submerged microfiltration system was used to investigate the influence of sodium alginate (SA) concentration and peristaltic pump rotation speed on the fouling under the conditions of (1) the same driving force and non-aerated-PAC, (2) different driving forces and non-aerated-PAC, and (3) different driving forces and aerated-PAC. The results showed that the normalized transmembrane pressure (TMP') increased linearly with decreasing normalized permeate flux (J') during the early microfiltration stage regardless of the operating conditions, indicating that the SA microfiltration process controlled by the peristaltic pump was non-constant-flux and non-constant-pressure. The latter filtration stage was considered constant-pressure filtration when 200-1,200 mg/L of SA was filtrated at the same rotation speed. During filtration of 800 mg/L of SA under the non-aerated-PAC condition, the later filtration stage was considered constant-pressure filtration when the peristaltic pump rotated at slower speeds of 15 and 30 rpm. This approached constant-flux filtration when the peristaltic pump rotated at faster speeds of 60 and 90 rpm, and PAC-aeration scouring was an effective measure for mitigating membrane fouling by SA.


Assuntos
Alginatos , Purificação da Água , Membranas Artificiais , Filtração/métodos , Purificação da Água/métodos
15.
Water Sci Technol ; 88(1): 321-338, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37452550

RESUMO

Chemical cleaning is one of the key technical means to control membrane fouling, restore membrane flux and ensure the stable operation of membrane systems. In the experiment, the six most representative chemical cleaning agents for ceramic membranes, such as sulfuric acid (H2SO4), sodium hydroxide (NaOH), sodium hypochlorite (NaClO), ethylenediaminetetraacetic acid disodium salt (EDTA-Na2), sodium dodecyl sulfate (SDS) and nonylphenol polyoxyethylene ether (OP-10), were used as research objects. The cleaning effect of the two-step combined cleaning of chemical cleaning agents on the fouled membrane was systematically investigated. Results showed that the order of the chemical cleaning agent had a significant effect on the cleaning effect. The best chemical cleaning program was determined to be NaClO first and then SDS: the fouled ceramic membrane was soaked in NaClO solution at 0.15% for 2.5 h and further soaked in SDS solution at five times its own critical micelle concentration for 2.5 h. The predicted long-term lifespan of the ceramic membranes was 4.91 years. Scanning electron microscopy-energy spectrum analysis showed that the surface roughness of the cleaned ceramic membrane was slightly higher than that of the new membrane. The contact angle was slightly lower than that of the new membrane.


Assuntos
Longevidade , Purificação da Água , Membranas Artificiais , Purificação da Água/métodos , Dodecilsulfato de Sódio , Cerâmica
16.
Anal Chim Acta ; 1274: 341572, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37455082

RESUMO

In this work, a novel solvent-free microfluidic method based liquid phase microextraction has been proposed for the first time. A comprehensive study of liquid phase microextraction (LPME) and electromembrane extraction (EME) implemented in microfluidic formats has been carried out to investigate the efficiency of biodegradable membranes (such as agarose) without organic solvent to develop fully environmental microfluidic methods. For this study, non-polar and polar basic compounds (five) were selected as model analytes and different agarose membrane compositions were synthesized and tested with and without organic solvent (solvent-free). Under optimal experimental conditions, the extraction efficiencies obtained using solvent-free LPME-chip devices were similar to the ones obtained using solvent-free EME-chip devices at very low voltages (0.25 V), however, LPME microfluidic format was selected due to its simplicity. The proposed green microfluidic device was successfully applied in urine samples with recoveries between 80 and 93% for all analytes and relative standard deviation below 7% for all analytes. Results were compared with experiments previously conducted using conventional (polypropylene) membranes, observing that solvent-free microfluidic systems based on biodegradable solid support materials have proven to be an attractive alternative and offered the same advantages in terms of membrane stability allowing consecutive extractions compared to supported liquid membranes (SLM) microfluidic methods.


Assuntos
Microextração em Fase Líquida , Solventes , Microextração em Fase Líquida/métodos , Sefarose , Dispositivos Lab-On-A-Chip , Microfluídica , Membranas Artificiais
17.
Langmuir ; 39(28): 9796-9807, 2023 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-37427880

RESUMO

As the key component of extracorporeal membrane oxygenation (ECMO), artificial lung membranes have low gas permeability and plasma leakage problems, and the contact between membrane materials and blood can cause coagulation, leading to the blockage of medical equipment and seriously threatening the safety of human life. In our work, poly(4-methyl-1-pentene) hollow fiber membranes (PMP HFMs) were prepared by the thermally induced phase separation (TIPS) method, the redox method was adopted for the surface hydroxylation of PMP HFMs, and then, heparin (Hep) and 2-(methacryloyloxy)ethyl(2-(trimethylammonio)ethyl) phosphate (MPC) were grafted to the surface of PMP HFMs to prepare anticoagulant coatings. The gas permeability and hemo-compatibility of the coatings were investigated by various characterization methods, such as gas flow meter, scanning electron microscope, extracorporeal circulation experiment, etc. The results show that PMP HFMs possess a bicontinuous pore structure with a dense surface layer, which could maintain good gas permeability with an oxygen permeance of 0.8 mL/bar·cm2·min and stable gas selectivity. Furthermore, the whole blood circulation of rabbit indicated that a composite surface of bioactive Hep and biopassive MPC might be used as artificial lung membranes without the formation of thrombosis within 21 days.


Assuntos
Membranas Artificiais , Fosforilcolina , Animais , Humanos , Coelhos , Fosforilcolina/química , Heparina , Pulmão , Oxigênio/química
18.
Chemosphere ; 337: 139317, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37392800

RESUMO

In this study, a photocatalytic biochar-TiO2 (C-Ti) composite was prepared using lignin as carbon precursor, and blended with PVDF polymer to fabricate PVDF/C-Ti MMMs via non-solvent induced phase inversion. The prepared membrane demonstrates both 1.5 times higher initial and recovered fluxes than the similarly prepared PVDF/TiO2 membrane, suggesting the C-Ti composite can help maintain higher photodegradation efficiency and better anti-fouling performance. In addition, the comparison of PVDF/C-Ti membrane against pristine PVDF membrane show that the reversible fouling and photodegradation reversible fouling of BSA increased from 10.1% to 6.4%-35.1% and 26.6%, respectively. And the FRR of PVDF/C-Ti membrane was 62.12%, 1.8 times that of PVDF membrane. The PVDF/C-Ti membrane was also applied for lignin separation, where the rejection to sodium lignin sulfonate was maintained at about 75%, and the flux recovery ratio after UV irradiation reached 90%. The demonstrated the advantages of PVDF/C-Ti membrane in photocatalytic degradation and antifouling performance.


Assuntos
Incrustação Biológica , Incrustação Biológica/prevenção & controle , Lignina , Membranas Artificiais
19.
Chemosphere ; 337: 139431, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37422217

RESUMO

Exploration and transportation of oil offshore can result in oil spills that cause a wide range of adverse environmental consequences and destroy aquatic life. Membrane technology outperformed the conventional procedures for oil emulsion separation due to its improved performance, reduced cost, removal capacity, and greater eco-friendly. In this study, a hydrophobic iron oxide-oleylamine (Fe-Ol) nanohybrid was synthesized and incorporated into polyethersulfone (PES) to prepare novel PES/Fe-Ol hydrophobic ultrafiltration (UF) mixed matrix membranes (MMMs). Several characterization techniques were performed to characterize the synthesized nanohybrid and fabricated membranes, including scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), contact angle, and zeta potential. The membranes' performance was assessed using a surfactant-stabilized (SS) water-in-hexane emulsion as a feed and a dead-end vacuum filtration setup. The incorporation of the nanohybrid enhanced the hydrophobicity, porosity, and thermal stability of the composite membranes. At 1.5 wt% Fe-Ol nanohybrid, the modified PES/Fe-Ol MMM membranes reported high water rejection efficiency of 97.4% and 1020.4 LMH filtrate flux. The re-usability and antifouling properties of the membrane were examined over five filtration cycles, demonstrating its great potential for use in water-in-oil separation.


Assuntos
Ultrafiltração , Água , Ultrafiltração/métodos , Água/química , Emulsões , Espectroscopia de Infravermelho com Transformada de Fourier , Membranas Artificiais , Interações Hidrofóbicas e Hidrofílicas
20.
Sci Rep ; 13(1): 11703, 2023 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-37474512

RESUMO

Biocompatibility and the ability to mediate the appropriate flux of ions, urea, and uremic toxins between blood and dialysate components are key parameters for membranes used in dialysis. Oxone-mediated TEMPO-oxidized cellulose nanomaterials have been demonstrated to be excellent additives in the production and tunability of ultrafiltration and dialysis membranes. In the present study, nanocellulose ionic liquid membranes (NC-ILMs) were tested in vitro and ex vivo. An increase in flux of up to two orders of magnitude was observed with increased rejection (about 99.6%) of key proteins compared to that of polysulfone (PSf) and other commercial membranes. NC-ILMs have a sharper molecular weight cut-off than other phase inversion polymeric membranes, allowing for high throughput of urea and a uremic toxin surrogate and limited passage of proteins in dialysis applications. Superior anti-fouling properties were also observed for the NC-ILMs, including a > 5-h operation time with no systemic anticoagulation in blood samples. Finally, NC-ILMs were found to be biocompatible in rat ultrafiltration and dialysis experiments, indicating their potential clinical utility in dialysis and other blood filtration applications. These superior properties may allow for a new class of membranes for use in a wide variety of industrial applications, including the treatment of patients suffering from renal disease.


Assuntos
Diálise Renal , Toxinas Biológicas , Ratos , Animais , Ultrafiltração , Soluções para Diálise , Proteínas , Membranas Artificiais , Ureia
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