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1.
J Environ Sci (China) ; 147: 392-403, 2025 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-39003057

RESUMO

This study used steel slag, fly ash, and metakaolin as raw materials (SFM materials) to create silica-alumina-based geopolymers that can solidify Hg2+ when activated with sodium-based water glass. The experiments began with a triangular lattice point mixing design experiment, and the results were fitted, analyzed, and predicted. The optimum SFM material mass ratio was found to be 70% steel slag, 25% fly ash, and 5% metakaolin. The optimum modulus of the activator was identified by comparing the unconfined compressive strength and solidifying impact on Hg2+of geosynthetics with different modulus. The SFM geopolymer was then applied in the form of potting to cure the granulated mercury tailings. The inclusion of 50% SFM material generated a geosynthetic that reduced mercury transport to the surface soil by roughly 90%. The mercury concentration of herbaceous plant samples was also reduced by 78%. It indicates that the SFM material can effectively attenuate the migration transformation of mercury. Finally, characterization methods such as XPS and FTIR were used to investigate the mechanism of Hg2+ solidification by geopolymers generated by SFM materials. The possible solidification mechanisms were proposed as alkaline environment-induced mercury precipitation, chemical bonding s, surface adsorption of Hg2+ and its precipitates by the geopolymer, and physical encapsulation.


Assuntos
Mercúrio , Mercúrio/química , Mercúrio/análise , Polímeros/química , Poluentes do Solo/química , Poluentes do Solo/análise , Mineração , Cinza de Carvão/química , Modelos Químicos
2.
ACS Appl Bio Mater ; 7(7): 4772-4784, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38963128

RESUMO

Textile-based wearable humidity sensors are of great interest for human healthcare monitoring as they can provide critical human-physiology information. The demand for wearable and sustainable sensing technology has significantly promoted the development of eco-friendly sensing solutions for potential real-world applications. Herein, a biodegradable cotton (textile)-based wearable humidity sensor has been developed using fabsil-treated cotton fabric coated with a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) sensing layer. The structural, chemical composition, hygroscopicity, and morphological properties are examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), contact angle measurement, and scanning electron microscopy (SEM) analysis. The developed sensor exhibited a nearly linear response (Adj. R-square value observed as 0.95035) over a broad relative humidity (RH) range from 25 to 91.5%RH displaying high sensitivity (26.1%/%RH). The sensor shows excellent reproducibility (on replica sensors with a margin of error ±1.98%) and appreciable stability/aging with time (>4.5 months), high flexibility (studied at bending angles 30°, 70°, 120°, and 150°), substantial response/recovery durations (suitable for multiple applications), and highly repeatable (multicyclic analysis) sensing performance. The prospective relevance of the developed humidity sensor toward healthcare applications is demonstrated via breathing rate monitoring (via a sensor attached to a face mask), distinguishing different breathing patterns (normal, deep, and fast), skin moisture monitoring, and neonatal care (diaper wetting). The multinode wireless connectivity is demonstrated using a Raspberry Pi Pico-based system for demonstrating the potential applicability of the developed sensor as a real-time humidity monitoring system for the healthcare sector. Further, the biodegradability analysis of the used textile is evaluated using the soil burial degradation test. The work suggests the potential applicability of the developed flexible and eco-friendly humidity sensor in wearable healthcare devices and other humidity sensing applications.


Assuntos
Umidade , Teste de Materiais , Têxteis , Dispositivos Eletrônicos Vestíveis , Humanos , Tamanho da Partícula , Tecnologia sem Fio , Materiais Biocompatíveis/química , Polímeros/química , Compostos Bicíclicos Heterocíclicos com Pontes/química
3.
Carbohydr Res ; 542: 109200, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38964015

RESUMO

The polymeric nanoparticles (PNPs) loaded with prednisolone were developed to exhibit pH-responsive properties owing to the attachment of a hydrazone linkage between the copolymer chitosan and mPEG. In the diseased cellular environment, the hydrazone bond tends to break due to reduced pH, leading to the release of the drug from the PNPs at the required site of action. The fabricated PNPs exhibit spherical morphology, optimum size (∼200 nm), negative surface charge, and monodispersed particle size distribution. The encapsulation efficiency of the PNPs was determined to be 71.1 ± 0.79 % and two experiments (polymer weight loss and drug release) confirmed the pH-responsive properties of the PNPs. The cellular study cytotoxicity assay showed biocompatibility of PNPs and drug molecule-mediated toxicity to A549 cells. The ligand atrial natriuretic peptide-attached PNPs internalized into A549 cells via natriuretic peptide receptor-A to achieve target specificity. The PNPs cytotoxicity and pH-response medicated inflammation reduction functionality was studied in inflammation-induced RAW264.7 cell lines. The study observed the PNPs effectively reduced the inflammatory mediators NO and ROS levels in RAW264.7. The results showed that pH-responsive properties of PNPs and this novel fabricated delivery system effectively treat inflammatory and cancer diseases.


Assuntos
Quitosana , Química Click , Nanopartículas , Quitosana/química , Quitosana/farmacologia , Concentração de Íons de Hidrogênio , Humanos , Camundongos , Animais , Nanopartículas/química , Células RAW 264.7 , Células A549 , Portadores de Fármacos/química , Portadores de Fármacos/síntese química , Sistemas de Liberação de Medicamentos , Tamanho da Partícula , Polímeros/química , Polímeros/síntese química , Polímeros/farmacologia , Liberação Controlada de Fármacos , Prednisolona/química , Prednisolona/farmacologia , Sobrevivência Celular/efeitos dos fármacos
4.
Methods Enzymol ; 700: 235-273, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38971602

RESUMO

Hierarchic self-assembly is the main mechanism used to create diverse structures using soft materials. This is a case for both synthetic materials and biomolecular systems, as exemplified by the non-covalent organization of lipids into membranes. In nature, lipids often assemble into single bilayers, but other nanostructures are encountered, such as bilayer stacks and tubular and vesicular aggregates. Synthetic block copolymers can be engineered to recapitulate many of the structures, forms, and functions of lipid systems. When block copolymers are amphiphilic, they can be inserted or co-assembled into hybrid membranes that exhibit synergistic structural, permeability, and mechanical properties. One example is the emergence of lateral phase separation akin to the raft formation in biomembranes. When higher-order structures, such as hybrid membranes, are formed, this lateral phase separation can be correlated across membranes in the stack. This chapter outlines a set of important methods, such as X-ray Scattering, Atomic Force Microscopy, and Cryo-Electron Microscopy, that are relevant to characterizing and evaluating lateral and correlated phase separation in hybrid membranes at the nano and mesoscales. Understanding the phase behavior of polymer-lipid hybrid materials could lead to innovative advancements in biomimetic membrane separation systems.


Assuntos
Microscopia Crioeletrônica , Bicamadas Lipídicas , Microscopia de Força Atômica , Polímeros , Microscopia Crioeletrônica/métodos , Polímeros/química , Bicamadas Lipídicas/química , Microscopia de Força Atômica/métodos , Difração de Raios X/métodos , Separação de Fases
5.
BMJ Open ; 14(7): e082380, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39009453

RESUMO

INTRODUCTION: Type II endoleaks (T2ELs) following endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) can lead to aneurysm growth, compromising the stent graft seal and risking rupture. Preventing these endoleaks during EVAR involves filling the AAA sac around the stent graft to exclude the aneurysm and block any arteries causing the endoleak. This study investigates the feasibility and safety of using AneuFix, a biocompatible injectable polymer developed by TripleMed (Geleen, the Netherlands), for aneurysmal sac filling during EVAR in high-risk T2EL patients. METHODS AND ANALYSIS: A feasibility, single-arm, single-centre clinical trial will initially include five patients with infrarenal AAA, eligible for EVAR, and at high risk for T2EL based on the number of patent lumbar arteries and the cross-sectional area of the aortic lumen at the level of the inferior mesenteric artery. Postevaluation by the Data Safety and Monitoring Board, the study cohort will extend to 25 patients. During EVAR and after stent graft deployment, the aneurysm sac is filled with AneuFix polymer using a filling sheath positioned parallel to the contralateral limb with the tip inside the aneurysm sac. Primary outcome is technical success (successful AAA sac filling). The secondary outcomes include clinical success at 6 and 12 months (occurrence of T2ELs and AAA growth assessed with CT angiography), intraoperative and perioperative complications, all endoleaks, adverse events, re-interventions, aneurysm rupture and patient survival. ETHICS AND DISSEMINATION: This trial was approved by the Dutch Authorities (Central Committee on Research Involving Human Subjects, IGJ), Amsterdam University Medical Centre Ethical Commission, and adheres to the Declaration of Helsinki and European Medical Device Regulation. Results will be shared at (inter)national conferences and in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04307992.


Assuntos
Aneurisma da Aorta Abdominal , Endoleak , Procedimentos Endovasculares , Estudos de Viabilidade , Polímeros , Humanos , Aneurisma da Aorta Abdominal/cirurgia , Procedimentos Endovasculares/métodos , Endoleak/prevenção & controle , Implante de Prótese Vascular/métodos , Stents , Prótese Vascular , Masculino , Feminino , Países Baixos , Correção Endovascular de Aneurisma
6.
Chem Pharm Bull (Tokyo) ; 72(7): 681-688, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39019599

RESUMO

Clarithromycin (CLA) is the preferred drug for treating respiratory infections in pediatric patients, but it has the drawbacks of extreme bitterness and poor water solubility. The purpose of this study was to improve solubility and mask the extreme bitterness of CLA. We use Hot Melt Extrusion (HME) to convert CLA and Eudragit® E100 into Solid Dispersion (SD). Differential scanning calorimetry (DSC) and Powder X-ray diffraction (PXRD) were used to identify the crystalline form of the prepared SDs, which showed that the crystalline CLA was converted to an amorphous form. At the same time, an increase in dissolution rate was observed, which is one of the properties of SD. The results showed that the prepared SD significantly increased the dissolution rate of crystalline CLA. Subsequently, the SD of CLA was prepared into a dry suspension with excellent suspending properties and a taste-masking effect. The bitterness bubble chart and taste radar chart showed that the SD achieved the bitter taste masking of CLA. Principal components analysis (PCA) of the data generated by the electronic tongue showed that the bitter taste of CLA was significantly suppressed using the polymer Eudragit® E100. Subsequently, a dry suspension was prepared from the SD of CLA. In conclusion, this work illustrated the importance of HME for preparing amorphous SD of CLA, which can solve the problems of bitterness-masking and poor solubility. It is also significant for the development of compliant pediatric formulations.


Assuntos
Claritromicina , Solubilidade , Suspensões , Paladar , Paladar/efeitos dos fármacos , Claritromicina/química , Claritromicina/farmacologia , Suspensões/química , Tecnologia de Extrusão por Fusão a Quente , Polímeros/química , Composição de Medicamentos , Temperatura Alta , Acrilatos
7.
ACS Appl Mater Interfaces ; 16(28): 36168-36193, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38954488

RESUMO

In the intricate landscape of Traumatic Brain Injury (TBI), the management of TBI remains a challenging task due to the extremely complex pathophysiological conditions and excessive release of reactive oxygen species (ROS) at the injury site and the limited regenerative capacities of the central nervous system (CNS). Existing pharmaceutical interventions are limited in their ability to efficiently cross the blood-brain barrier (BBB) and expeditiously target areas of brain inflammation. In response to these challenges herein, we designed novel mussel inspired polydopamine (PDA)-coated mesoporous silica nanoparticles (PDA-AMSNs) with excellent antioxidative ability to deliver a new potential therapeutic GSK-3ß inhibitor lead small molecule abbreviated as Neuro Chemical Modulator (NCM) at the TBI site using a neuroprotective peptide hydrogel (PANAP). PDA-AMSNs loaded with NCM (i.e., PDA-AMSN-D) into the matrix of PANAP were injected into the damaged area in an in vivo cryogenic brain injury model (CBI). This approach is specifically built while keeping the logic AND gate circuit as the primary focus. Where NCM and PDA-AMSNs act as two input signals and neurological functional recovery as a single output. Therapeutically, PDA-AMSN-D significantly decreased infarct volume, enhanced neurogenesis, rejuvenated BBB senescence, and accelerated neurological function recovery in a CBI.


Assuntos
Antioxidantes , Bivalves , Lesões Encefálicas Traumáticas , Indóis , Nanocompostos , Neurogênese , Estresse Oxidativo , Polímeros , Indóis/química , Indóis/farmacologia , Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/patologia , Lesões Encefálicas Traumáticas/metabolismo , Polímeros/química , Polímeros/farmacologia , Animais , Estresse Oxidativo/efeitos dos fármacos , Antioxidantes/química , Antioxidantes/farmacologia , Nanocompostos/química , Bivalves/química , Neurogênese/efeitos dos fármacos , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/farmacologia , Dióxido de Silício/química , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Masculino
8.
ACS Appl Mater Interfaces ; 16(28): 36002-36016, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38954606

RESUMO

The design of adhesive and conductive soft hydrogels using biopolymers with tunable mechanical properties has received significant interest in the field of wearable sensors for detecting human motions. These hydrogels are primarily fabricated through the modification of biopolymers to introduce cross-linking sites, the conjugation of adhesive components, and the incorporation of conductive materials into the hydrogel network. The development of a multifunctional copolymer that integrates adhesive and conductive properties within a single polymer chain with suitable cross-linking sites eliminates the need for biopolymer modification and the addition of extra conductive and adhesive components. In this study, we synthesized a copolymer based on poly([2-(methacryloyloxy)ethyl] trimethylammonium chloride-co-dopamine methacrylamide) (p(METAC-DMA)) using a controlled radical polymerization, allowing for the efficient conjugation of both adhesive and conductive units within a single polymer chain. Subsequently, our multifunctional hydrogel named Gel-MD was fabricated by mixing the p(METAC-DMA) copolymer with non-modified gelatin in which cross-linking took place in an oxidative environment. We confirmed the biocompatibility of the Gel-MD hydrogel through in vitro studies using NIH 3T3 cells as well as in vivo subcutaneous implantation in rats. Furthermore, the Gel-MD hydrogel was effective and sensitive in detecting various human motions, making it a promising wearable sensor for health monitoring and diagnosis.


Assuntos
Hidrogéis , Dispositivos Eletrônicos Vestíveis , Animais , Camundongos , Células NIH 3T3 , Hidrogéis/química , Ratos , Humanos , Polímeros/química , Condutividade Elétrica , Adesivos/química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/síntese química , Acrilamidas/química , Ratos Sprague-Dawley
9.
ACS Appl Mater Interfaces ; 16(28): 35985-36001, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38958411

RESUMO

Upconversion nanoparticles (UCNPs) are materials that provide unique advantages for biomedical applications. There are constantly emerging customized UCNPs with varying compositions, coatings, and upconversion mechanisms. Cellular uptake is a key parameter for the biological application of UCNPs. Uptake experiments have yielded highly varying results, and correlating trends between cellular uptake with different types of UCNP coatings remains challenging. In this report, the impact of surface polymer coatings on the formation of protein coronas and subsequent cellular uptake of UCNPs by macrophages and cancer cells was investigated. Luminescence confocal microscopy and elemental analysis techniques were used to evaluate the different coatings for internalization within cells. Pathway inhibitors were used to unravel the specific internalization mechanisms of polymer-coated UCNPs. Coatings were chosen as the most promising for colloidal stability, conjugation chemistry, and biomedical applications. PIMA-PEG (poly(isobutylene-alt-maleic) anhydride with polyethylene glycol)-coated UCNPs were found to have low cytotoxicity, low uptake by macrophages (when compared with PEI, poly(ethylenimine)), and sufficient uptake by tumor cells for surface-loaded drug delivery applications. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) studies revealed that PIMA-coated NPs were preferentially internalized by the clathrin- and caveolar-independent pathways, with a preference for clathrin-mediated uptake at longer time points. PMAO-PEG (poly(maleic anhydride-alt-1-octadecene) with polyethylene glycol)-coated UCNPs were internalized by energy-dependent pathways, while PAA- (poly(acrylic acid)) and PEI-coated NPs were internalized by multifactorial mechanisms of internalization. The results indicate that copolymers of PIMA-PEG coatings on UCNPs were well suited for the next-generation of biomedical applications.


Assuntos
Nanopartículas , Coroa de Proteína , Coroa de Proteína/química , Coroa de Proteína/metabolismo , Humanos , Nanopartículas/química , Camundongos , Animais , Células RAW 264.7 , Macrófagos/metabolismo , Macrófagos/efeitos dos fármacos , Polietilenoglicóis/química , Polímeros/química , Propriedades de Superfície , Anidridos Maleicos/química , Linhagem Celular Tumoral , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia
10.
ACS Appl Mater Interfaces ; 16(28): 37087-37099, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38958653

RESUMO

Hydrogels, as flexible materials, have been widely used in the field of flexible sensors. Human sweat contains a variety of biomarkers that can reflect the physiological state of the human body. Therefore, it is of great practical significance and application value to realize the detection of sweat composition and combine it with human motion sensing through a hydrogel. Based on mussel-inspired chemistry, polydopamine (PDA) and gold nanoparticles (AuNPs) were coated on the surface of cellulose nanocrystals (CNCs) to obtain CNC-based nanocomposites (CNCs@PDA-Au), which could simultaneously enhance the mechanical, electrochemical, and self-healing properties of hydrogels. The CNCs@PDA-Au was composited with poly(vinyl alcohol) (PVA) hydrogel to obtain the nanocomposite hydrogel (PVA/CNCs@PDA-Au) by freeze-thaw cycles. The PVA/CNCs@PDA-Au has excellent mechanical strength (7.2 MPa) and self-healing properties (88.3%). The motion sensors designed with PVA/CNCs@PDA-Au exhibited a fast response time (122.9 ms), wide strain sensing range (0-600.0%), excellent stability, and fatigue resistance. With the unique electrochemical redox properties of uric acid, the designed hydrogel sensor successfully realized the detection of uric acid in sweat with a wide detection range (1.0-100.0 µmol/L) and low detection limit (0.42 µmol/L). In this study, the dual detection of human motion and uric acid in sweat was successfully realized by the designed PVA/CNCs@PDA-Au nanocomposite hydrogel.


Assuntos
Celulose , Ouro , Hidrogéis , Nanocompostos , Polímeros , Suor , Celulose/química , Nanocompostos/química , Humanos , Hidrogéis/química , Ouro/química , Suor/química , Polímeros/química , Nanopartículas Metálicas/química , Álcool de Polivinil/química , Nanopartículas/química , Indóis/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Limite de Detecção , Movimento (Física)
11.
Environ Sci Pollut Res Int ; 31(32): 45204-45216, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38958860

RESUMO

Ionic polymers functionalized with hydroxyl, carboxyl, and amino groups can enhance the catalytic activity of catalysts. However, the straightforward preparation of bifunctional ionic polymers containing abundant ionic active sites and hydrogen bond donors remains challenging. In this study, a series of porous ionic polymers (BZIs) containing different hydrogen bond donors (-NH2, -OH, -COOH) were prepared through a simple one-pot Friedel-Crafts alkylation using benzimidazole derivatives and benzyl bromide. The structures and properties of BZIs were characterized by various techniques such as Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, solid-state nuclear magnetic resonance, and scanning electron microscopy. Among the prepared catalysts (BZI-NH2, BZI-OH, and BZI-COOH), BZI-NH2 exhibited the highest catalytic activity and recyclability, achieving a yield of 97% in the CO2 cycloaddition. The synergistic effect of Br-, hydrogen bond donors (-NH-, -NH2), and N+ in BZI-NH2 was found to contribute to its superior catalytic performance. DFT calculations were employed to study the effect of hydrogen bonds, Br-, and N+ in BZI-NH2 and BZI-OH on the CO2 cycloaddition. Using BZI-NH2 as an example, a mechanism was proposed for the synergistic effect between amino groups and bromide ions in catalyzing the CO2 cycloaddition reaction.


Assuntos
Benzimidazóis , Dióxido de Carbono , Reação de Cicloadição , Benzimidazóis/química , Catálise , Dióxido de Carbono/química , Ligação de Hidrogênio , Polímeros/química
12.
ACS Appl Mater Interfaces ; 16(28): 36953-36961, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38976781

RESUMO

Metal-organic frameworks (MOFs) are favorable hosting materials for fixing enzymes to construct enzyme@MOF composites and to expand the applications of biocatalysts. However, the rigid structure of MOFs without tunable hollow voids and a confinement effect often limits their catalytic activities. Taking advantage of the smart soft polymers to overcome the limitation, herein, a protection protocol to encapsulate the enzyme in zeolitic imidazolate framework-8 (ZIF-8) was developed using a glutathione-sensitive liposome (L) as a soft template. Glucose oxidase (GOx) and horseradish peroxidase (HRP) were first anchored on a light- and thermoresponsive porous poly(styrene-maleic anhydride-N,N-dimethylaminoethyl methacrylate-spiropyran) membrane (PSMDSP) to produce PSMDSP@GOx-HRP, which could provide a confinement effect by switching the UV irradiation or varying the temperature. Afterward, embedding PSMDSP@GOx-HRP in L and encapsulating PSMDSP@GOx-HRP@L into hollow ZIF-8 (HZIF-8) to form PSMDSP@GOx-HRP@HZIF-8 composites were performed, which proceeded during the crystallization of the framework following the removal of L by adding glutathione. Impressively, the biocatalytic activity of the composites was 4.45-fold higher than that of the free enzyme under UV irradiation at 47 °C, which could benefit from the confinement effect of PSMDSP and the conformational freedom of the enzyme in HZIF-8. The proposed composites contributed to the protection of the enzyme against harsh conditions and exhibited superior stability. Furthermore, a colorimetric assay based on the composites for the detection of serum glucose was established with a linearity range of 0.05-5.0 mM, and the calculated LOD value was 0.001 mM in a cascade reaction system. This work provides a universal design idea and a versatile technique to immobilize enzymes on soft polymer membranes that can be encapsulated in porous rigid MOF-hosts. It also holds potential for the development of smart polymer@enzyme@HMOFs biocatalysts with a tunable confinement effect and high catalytic performance.


Assuntos
Biocatálise , Enzimas Imobilizadas , Glucose Oxidase , Peroxidase do Rábano Silvestre , Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Glucose Oxidase/química , Glucose Oxidase/metabolismo , Peroxidase do Rábano Silvestre/química , Peroxidase do Rábano Silvestre/metabolismo , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Temperatura , Polímeros/química , Zeolitas/química , Luz , Lipossomos/química
13.
Water Environ Res ; 96(7): e11081, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39023047

RESUMO

Powdered activated carbon (PAC) has better adsorption performance than granular activated carbon (GAC) and is widely used in water purification. In most cases, PAC is dosed into water directly, then precipitated as sludge, and landfilled. In this study, PAC was mixed with a polymer and dissolved in dimethylformamide (DMF) solvent to form a PAC-loaded membrane, which was then tested for chloroform removal. The chloroform adsorption capacity of the PAC membrane increased with increasing membrane thickness because of higher carbon loading. However, regardless of membrane thickness, the flux of the PAC membranes was similar since flux resistance predominantly occurred at the top dense polymer surface. This dense surface can be removed by sandpaper polishing, where the adsorption capacity of the polished PAC membranes was 20% higher than the unpolished membranes because of more even distribution of feed water on the polished surface. Removal of the dense surface via polishing increased the flux by 97% to 130%, exceeding the flux of typical household carbon block filters. Using DMF to regenerate the membrane recovered 48% to 66% of the initial adsorption capacity. Thermal regeneration of the exhausted PAC membrane at 250°C was more effective than DMF regeneration (both in terms of cost and performance), with 83% to 94% PAC membrane regeneration efficiency over four regeneration recycles. After four thermal regeneration cycles, flux increased by 300% and the membrane became brittle because of thermal aging of the polymer, indicating that a total of 6 h of regeneration time (equivalent to three cycles in this study) was the limit for effective PAC membrane performance. PRACTITIONER POINTS: Powdered activated carbon was immobilized on a membrane to remove chloroform from water. Thicker membranes increased adsorption capacity but did not impact flux. Flux and capacity increased using polishing to remove the dense polymer surface and more evenly distribute flow across the membrane. Thermal regeneration of the membrane at 250°C was effective for up to three cycles and outperformed solvent-based regeneration. PAC-loaded filters are relevant for applications such as household carbon block filtration.


Assuntos
Carvão Vegetal , Clorofórmio , Membranas Artificiais , Polímeros , Solventes , Poluentes Químicos da Água , Purificação da Água , Clorofórmio/química , Purificação da Água/métodos , Carvão Vegetal/química , Solventes/química , Polímeros/química , Poluentes Químicos da Água/química , Adsorção
14.
Phys Rev E ; 109(6-1): 064406, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39021027

RESUMO

Protein-mediated interactions are ubiquitous in the cellular environment, and particularly in the nucleus, where they are responsible for the structuring of chromatin. We show through molecular-dynamics simulations of a polymer surrounded by binders that the strength of the binder-polymer interaction separates an equilibrium from a nonequilibrium regime. In the equilibrium regime, the system can be efficiently described by an effective model in which the binders are traced out. Even in this case, the polymers display features that are different from those of a standard homopolymer interacting with two-body interactions. We then extend the effective model to deal with the case where binders cannot be regarded as in equilibrium and a new phenomenology appears, including local blobs in the polymer. An effective description of this system can be useful in elucidating the fundamental mechanisms that govern chromatin structuring in particular and indirect interactions in general.


Assuntos
Cromatina , Cromatina/metabolismo , Ligação Proteica , Simulação de Dinâmica Molecular , Proteínas/metabolismo , Proteínas/química , Modelos Moleculares , Polímeros/metabolismo , Polímeros/química
16.
Chin J Dent Res ; 27(2): 161-168, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38953481

RESUMO

OBJECTIVE: To evaluate the effect of different adhesives and veneering resins on the shear bond strength (SBS) of polyetheretherketone (PEEK). METHODS: A total of 138 PEEK specimens were randomly divided into 6 groups according to adhesive material application: Control (C, no application), Adhese Universal (A) (Ivoclar Vivadent, Schaan, Liechtenstein), Gluma Bond Universal (G) (Heraeus Kulzer, South Bend, IN, USA), G-PremioBOND (P) (GC Corporation, Tokyo, Japan), Single Bond Universal (S) (3M, Saint Paul, MN, USA) and visio.link (V) (Bredent, Senden, Germany). Each adhesive group was divided into two subgroups according to the type of veneering material: Estenia direct composite (D) and Gradia Plus indirect composite (IN) (both GC Corporation). After the veneering process, the specimens were aged by thermal cycling. Kruskal-Wallis and Mann-Whitney U tests were used for SBS analysis (P < 0.05). RESULTS: The highest SBS results were obtained in the VIN group, followed by the VD, PD, GIN, AIN, AD, SIN, SD, PIN, GD, CIN and CD groups, respectively (P = 0.001). There were no significant differences in terms of the type of veneering composite when the same adhesive was applied (P > 0.05), except for Gluma Bond Universal (P = 0.009). All the adhesives tested showed clinically acceptable SBS results. CONCLUSION: Visio.link offered the highest adhesion to PEEK, whereas the tested universal adhesives may be used as an alternative to visio.link in clinical settings. It was determined that changing the veneer type has no statistical difference when the same adhesive material is used.


Assuntos
Benzofenonas , Resinas Compostas , Facetas Dentárias , Cetonas , Polietilenoglicóis , Polímeros , Resistência ao Cisalhamento , Cetonas/química , Teste de Materiais , Colagem Dentária , Humanos , Cimentos de Resina , Análise do Estresse Dentário , Bis-Fenol A-Glicidil Metacrilato
17.
Annu Rev Biomed Eng ; 26(1): 415-440, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38959388

RESUMO

Autoimmunity, allergy, and transplant rejection are a collection of chronic diseases that are currently incurable, drastically decrease patient quality of life, and consume considerable health care resources. Underlying each of these diseases is a dysregulated immune system that results in the mounting of an inflammatory response against self or an innocuous antigen. As a consequence, afflicted patients are required to adhere to lifelong regimens of multiple immunomodulatory drugs to control disease and reclaim agency. Unfortunately, current immunomodulatory drugs are associated with a myriad of side effects and adverse events, such as increased risk of cancer and increased risk of serious infection, which negatively impacts patient adherence rates and quality of life. The field of immunoengineering is a new discipline that aims to harness endogenous biological pathways to thwart disease and minimize side effects using novel biomaterial-based strategies. We highlight and discuss polymeric micro/nanoparticles with inherent immunomodulatory properties that are currently under investigation in biomaterial-based therapies for treatment of autoimmunity, allergy, and transplant rejection.


Assuntos
Autoimunidade , Rejeição de Enxerto , Hipersensibilidade , Polímeros , Humanos , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Polímeros/química , Autoimunidade/efeitos dos fármacos , Hipersensibilidade/imunologia , Hipersensibilidade/terapia , Animais , Materiais Biocompatíveis/química , Nanopartículas/química , Doenças Autoimunes/terapia , Doenças Autoimunes/imunologia , Agentes de Imunomodulação/uso terapêutico , Fatores Imunológicos/uso terapêutico
18.
J Environ Manage ; 365: 121611, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38959769

RESUMO

Ultrafiltration technology, separating water from impurities by the core membrane, is an effective strategy for treating wastewater to meet the ever-growing requirement of clean and drinking water. However, the similar nature of hydrophobic organic pollutants and the membrane surface leads to severe adsorption and aggregation, resulting unavoidable membrane degradation of penetration and rejection. The present study presents a novel block amphiphilic polymer, polyethersulfone-g-carboxymethyl chitosan@MWCNT (PES-g-CMC@MWCNT), which is synthesized by grafting hydrophobic polyethersulfone to hydrophilic carboxymethyl chitosan in order to suspend CMC in organic solution. A mixture of hydrophilic carboxymethyl chitosan and hydrophobic polymers (polyethersulfone), in which hydrophilic segments are bonded to hydrophobic segments, could provide hydrophilic groups, as well as gather and remain stable on membrane surfaces by their hydrophobic interaction for improved compatibility and durability. The resultant ultrafiltration membranes exhibit high water flux (198.10 L m-2·h-1), suitable hydrophilicity (64.77°), enhanced antifouling property (82.96%), while still maintains excellent rejection of bovine serum albumin (91.75%). There has also been an improvement in membrane cross-sectional morphology, resulting in more regular pores size (47.64 nm) and higher porosity (84.60%). These results indicate that amphiphilic polymer may be able to significantly promote antifouling and permeability of ultrafiltration membranes.


Assuntos
Quitosana , Interações Hidrofóbicas e Hidrofílicas , Membranas Artificiais , Polímeros , Sulfonas , Ultrafiltração , Polímeros/química , Quitosana/química , Quitosana/análogos & derivados , Sulfonas/química , Adsorção , Purificação da Água/métodos , Incrustação Biológica/prevenção & controle
19.
J Environ Manage ; 365: 121668, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38963971

RESUMO

An in-depth study of the oxidative liquefaction process has been provided to degrade the polymeric waste from personal protective equipment (PPEs) and wind turbine blades (WTBs). Thermogravimetric investigations demonstrate that WTBs have three prominent peaks throughout the degradation, whereas PPEs display solitary peak features. Experiments are carried out employing specific experimental design approaches, namely the Central Composite Face-Centered Plan (CCF) for WTBs and the Central Composition Design with Fractional Factorial Design for PPEs in a batch-type reactor at temperature ranges of 250-350 °C, pressures of 20-40 bar, residence times of 30-90 min, H2O2 concentrations of 15-45 %, and waste/liquid ratios of 5-25 % for WTBs. These values were 200-300 °C, 30 bar, 45 min, 30-60 % and 5-7 % for PPE. A detailed comparison has been provided in the context of total polymer degradation (TPD) for PPE and WTBs. Liquid products from both types of wastes after the oxidative liquefaction process are subjected to gas chromatography with flame ionization detection (GC-FID) to identify the existence of oxygenated chemical compounds (OCCs). For WTBs, TPD was 20-49 % and this value was 55-96 % for PPE while the OCC yield for WTBs (36.31 g/kg - 210.59 g/kg) and PPEs (39.93 g/kg - 212.66 g/kg) was also calculated. Detailed optimization of experimental plans was carried out by performing the analysis of variance (ANOVA) and optimization goals were maximum TPD and OCCs yields against the minimum energy consumption, though a considerable amount of complex polymer waste can be reduced and high concentrations of OCC can be achieved, which could be applied for commercial and environmental benefits.


Assuntos
Polímeros , Polímeros/química , Equipamento de Proteção Individual , Oxirredução , Vento , Gerenciamento de Resíduos/métodos , Peróxido de Hidrogênio/química
20.
Vitam Horm ; 125: 149-182, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38997163

RESUMO

The century old Maillard reactions continue to draw the interest of researchers in the fields of Food Science and Technology, and Health and Medical Sciences. This chapter seeks to simplify and update this highly complicated, multifaceted topic. The simple nucleophilic attack of an amine onto a carbonyl group gives rise to a series of parallel and subsequent reactions, occurring simultaneously, resulting into a vast array of low and high mass compounds. Recent research has focused on: (1) the formation and transformation of α-dicarbonyl compounds, highly reactive intermediates which are essential in the development of the desired color and flavor of foods, but also lead to the production of the detrimental advanced glycation end products (AGEs); (2) elucidation of the structures of melanoidins in different foods and their beneficial effects on human health; and (3) harmful effects of AGEs on human health. Considering that MRs have both positive and negative consequences, their control to accentuate the former and to mitigate the latter, is also being conscientiously investigated with the use of modern techniques and technology.


Assuntos
Produtos Finais de Glicação Avançada , Reação de Maillard , Humanos , Produtos Finais de Glicação Avançada/metabolismo , Produtos Finais de Glicação Avançada/química , Polímeros/química , Animais
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