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1.
J Hazard Mater ; 421: 126741, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34352526

RESUMO

Hydrochar (AAHC) with rich carboxylate groups was prepared by one-step hydrothermal carbonization (HTC) of bamboo and acrylic acid with the presence of ammonium persulphate, and then activated by a sodium hydroxide solution. AAHC was featured by elemental analysis, SEM, XPS, FTIR, Zeta potential analysis and N2 adsorption-desorption isotherms, and applied to test adsorptive ability of methylene blue (MB) by batch sorption experiments. Despite a small Brunauer-Emmett-Teller (BET) surface area of 5.03 m2·g-1, AAHC has excellent MB adsorbing capacity owing to the richness of carboxylate groups. Compared with hydrochar produced without adding ammonium persulphate, AAHC exhibits larger BET surface, pore volume and carboxylate groups, indicating a small amount of ammonium persulfate plays an important role in HTC in addition to the free radical initiator. This work provides a facile and cheap method combining HTC and polymerization for preparation of carboxylate-rich hydrochar.


Assuntos
Azul de Metileno , Poluentes Químicos da Água , Acrilatos , Adsorção , Sulfato de Amônio , Azul de Metileno/análise , Poluentes Químicos da Água/análise
2.
J Colloid Interface Sci ; 607(Pt 1): 76-88, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34492356

RESUMO

Dual stimuli-responsive nanogels (NGs) have gained popularity in the field of bio medicine due to their versatile nature of applicability. Poly(N-isopropylacrylamide)-co-poly(acrylic acid) (pNIPAm-pAAc)-based NGs provide such dual stimuli-response with pNIPAm and pAAc providing thermal and pH-based responses, respectively. Studying the growth of these NGs, as well as, understanding the effect of the incorporation of pAAc in the NG matrix, is important in determining the physico-chemical properties of the NG. Studies have been conducted investigating the effect of increasing pAAc content in the NGs, however, these are not detailed in understanding its effects on the physico-chemical properties of the pNIPAm-pAAc-based NGs. Also, the biocompatibility of the NGs have not been previously reported using human whole blood model. Herein, we report the effect of different reaction parameters, such as surfactant amount and reaction atmosphere, on the growth of pNIPAm-pAAc-based NGs. It is shown that the size of the NGs can be precisely controlled from ~130 nm to ~400 nm, by varying the amount of surfactant and the reaction atmosphere. The effect of increasing incorporation of pAAc in the NG matrix on its physico-chemical properties has been investigated. The potential of these NGs as drug delivery vehicles is investigated by conducting loading and release studies of a model protein drug, cytochrome C (Cyt C) from the NGs at temperature above the volume phase transition temperature (VPTT) and acidic pH. An ex vivo human whole blood model was used to investigate biocompatibility of the NGs by quantifying inflammatory responses during NG exposure. The NGs did not induce any significant production of chemokine IL-8 or pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α), and the cell viability in human whole blood was maintained during 4 h exposure. The NGs did neither activate the complement system, as determined by low Terminal Complement Complex (TCC) activation and Complement Receptor 3 (CR3) activation assays, thereby overall suggesting that the NGs could be potential candidates for biomedical applications.


Assuntos
Preparações Farmacêuticas , Acrilatos , Humanos , Nanogéis , Transição de Fase , Temperatura
3.
Talanta ; 237: 122950, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736676

RESUMO

Amplification of electrochemical signal in order to betterment of limit of detection in determination of biomarkers has an important role in early detection of some dangerous diseases such as cancers. For this purpose, in this research, two types of poly (styrene)-block-poly (acrylic acid) amphiphilic copolymer (PS61-b-PAA596 and PS596-b-PAA61) were synthesized by controlled radical polymerization method via reversible addition-fragmentation chain transfer polymerization (RAFT) technique. Chemical structure of block copolymers was confirmed by FT-IR spectroscopy and their surface morphology was assessed by scanning electron microscopy (SEM). Self-assembly of these block copolymers into polymeric vesicles (polymersomes), loading and release efficiency of methylene blue as an electroactive indicator were investigated in DMF and THF solvents. On the basis of our findings PS61-b-PAA596 has better capability for loading and release of MB than PS596-b-PAA61. Then the obtained methylene blue-loaded polymersome successfully used for development of an aptasensor toward determination of trace amounts of myoglobin. The proposed aptasensor showed a wide linear range from 1.0 aM to 1.0 µM with an ultra-low detection limit of 0.73 aM. Applying this amplification strategy, determination of myoglobin in real samples was successfully performed.


Assuntos
Azul de Metileno , Mioglobina , Acrilatos , Técnicas Eletroquímicas , Espectroscopia de Infravermelho com Transformada de Fourier , Estireno
4.
Mater Sci Eng C Mater Biol Appl ; 130: 112436, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34702521

RESUMO

Improving wound healing by developing innovative dressing materials has been an important focus over the past few years in the biomedical field. In this regard, the current study focuses on developing new dressings based on acrylate-endcapped urethane-based polymers (AUPs). The materials have been processed into films and electrospun mats. Exudate uptake capacity, mechanical properties and fiber morphology were evaluated herein. The results showed superior uptake capacity of both films and mats when compared to Aquacel®Ag, Exufiber® and Help®. Addition of a high molar mass poly(ethylene glycol) to the AUP polymers benefits both the film and electrospun dressings in terms of flexibility and elongation. An in vivo study was conducted to assess the wound healing properties of these dressings on an acute wound model induced to rats. A macroscopic evaluation indicated that wound contraction and wound fraction percentages were improved significantly in case of the AUP-materials when compared to both the positive (Aquacel®Ag) and negative (Exufiber® and Help®) controls. A histopathological assay, to underline the changes noticed on a macroscopical level, was also performed. The data obtained proved that the developed dressings are beneficial towards tissue regeneration and accelerated wound healing. These findings offer a practical yet adequate strategy for the fabrication of acrylate-endcapped urethane-based materials for wound healing applications.


Assuntos
Hidrogéis , Uretana , Acrilatos , Animais , Bandagens , Hidrogéis/farmacologia , Ratos , Cicatrização
5.
Int J Pharm ; 608: 121121, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-34560203

RESUMO

The objective of this work was to evaluate the potential use of a new polymer (PAMgA) in the development sustained release matrix tablets for the treatment of bowel inflammatory diseases. For this purpose, budesonide, a highly lipophilic compound, was used as model drug. Tablets with two reticulation grades of PAMgA (PAMgA 5 and 40) and with 9 mg of budesonide were developed and characterized. All the studies were carried out using biorelevant media (FaSSGF and FaSSIF). Swelling and erosion of PAMgA tablets was influenced by the reticulation grade of the polymer and the biorelevant media assayed, being water uptake higher for PAMgA 40 tablets in intestinal fluid, whereas PAMgA 5 showed more intense erosion in this biorelevant medium. Budesonide was released slowly from PAMgA tablets, both in gastric and intestinal environment, following Super case II transport kinetics (relaxation-controlled delivery), with a lag time of around 1-2 h. When the dissolution medium was changed sequentially throughout the trial, 75% of the budesonide dose was released in a sustained manner between 4 and 20 h of testing from PAMgA tablets, showing a more controlled budesonide release than Entocort® and Budenofalk® (commercially available sustained release formulations of budesonide). In conclusion, PAMgA polymer allows controlling the release of highly lipophilic drugs as budesonide, being an useful excipient for the development of sustained release matrix tablets.


Assuntos
Hidrogéis , Doenças Inflamatórias Intestinais , Acrilatos , Preparações de Ação Retardada , Humanos , Solubilidade , Comprimidos
6.
J Phys Chem Lett ; 12(38): 9275-9282, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34534434

RESUMO

The role of water in the excellent biocompatibility of the acrylate-based polymers widely used for antibiofouling coating material has been realized previously. Here, we report femtosecond mid-infrared pump-probe spectroscopy of the OD stretch band of HOD molecule adsorbed on highly biocompatible poly(2-methoxyethyl) acrylate [PMEA] and poorly biocompatible poly(2-phenoxyethyl) acrylate [PPEA], both of which reveal that there are two water species with significantly different vibrational lifetime. PMEA interacts more strongly with water than PPEA through the H-bonding interaction between carbonyl (C═O) and water. The vibrational lifetime of the OD stretch in PPEA is notably longer by factors of 3 and 7 than those in PMEA and bulk water, respectively. The IR-pump visible-probe photothermal imaging further unravels substantial spatial overlap between polymer CO group and water for hydrated PMEA and a significant difference in surface morphology than those in PPEA, which exhibits the underlying relationships among polymer-water interaction, surface morphology, and biocompatibility.


Assuntos
Acrilatos/química , Materiais Biocompatíveis/química , Polímeros/química , Água/química , Adsorção , Simulação de Dinâmica Molecular , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície
7.
Appl Microbiol Biotechnol ; 105(18): 7023-7034, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34477938

RESUMO

In the current study, the polyurethane acrylate (PUA) polymer was synthesized by the addition reaction between an isophorone diisocyanate (IPDI) and 2-hydroxyethyl acrylate and cured by polyol. Different properties of the synthesized PUA were determined through diverse analysis methods. The polyurethane acrylate (PUA)/natural filler-based composite (rhizome water extract of Costus speciosus) was prepared as an antifouling agent. The results revealed that the lowest weight loss percentages were detected at 2 wt% PUA/natural filler composite loadings with Escherichia coli (ATCC 23,282) and Pseudomonas aeruginosa (ATCC 10,145). The decreased weight loss percentage may be attributed to the well dispersed natural composite resulting in a slippery surface that can prevent fouling adhesion. It was concluded that the PUA/natural filler composite might be considered an eco-friendly and economical solution to the biofouling problem. KEY POINTS: • A novel strategy for anti-biofouling. • A new composite reduced Gram-negative bacteria.


Assuntos
Incrustação Biológica , Acrilatos , Incrustação Biológica/prevenção & controle , Escherichia coli , Poliuretanos , Pseudomonas aeruginosa
8.
Molecules ; 26(18)2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34576926

RESUMO

Novel UV-curable polyurethane acrylate (PUA) resins were developed from rubber seed oil (RSO). Firstly, hydroxylated rubber seed oil (HRSO) was prepared via an alcoholysis reaction of RSO with glycerol, and then HRSO was reacted with isophorone diisocyanate (IPDI) and hydroxyethyl acrylate (HEA) to produce the RSO-based PUA (RSO-PUA) oligomer. FT-IR and 1H NMR spectra collectively revealed that the obtained RSO-PUA was successfully synthesized, and the calculated C=C functionality of oligomer was 2.27 per fatty acid. Subsequently, a series of UV-curable resins were prepared and their ultimate properties, as well as UV-curing kinetics, were investigated. Notably, the UV-cured materials with 40% trimethylolpropane triacrylate (TMPTA) displayed a tensile strength of 11.7 MPa, an adhesion of 2 grade, a pencil hardness of 3H, a flexibility of 2 mm, and a glass transition temperature up to 109.4 °C. Finally, the optimal resin was used for digital light processing (DLP) 3D printing. The critical exposure energy of RSO-PUA (15.20 mJ/cm2) was lower than a commercial resin. In general, this work offered a simple method to prepare woody plant oil-based high-performance PUA resins that could be applied in the 3D printing industry.


Assuntos
Acrilatos/química , Gorduras Insaturadas/química , Poliuretanos/química , Impressão Tridimensional , Géis/química , Dureza , Hidroxilação , Espectroscopia de Ressonância Magnética , Resinas Sintéticas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Termogravimetria , Raios Ultravioleta
9.
J Mech Behav Biomed Mater ; 124: 104839, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34547607

RESUMO

Polymeric hydrogels continue to find a wide range of applications. However, a major drawback of hydrogels is the lack of mechanical strength. In this regard, "Double Network Hydrogels" (DN) have shown great promise recently. The toughness in DN hydrogels originates from the synergistic effect of two polymeric networks. In this work, we have synthesized a DN hydrogel consisting of a tightly cross linked carboxymethylcellulose (CMC) as the first network and loosely cross linked poly(hydroxyethylacrylate) (PHEA) as a second network (CMC-PHEA-DN). The required flexibility in the second network (PHEA) was induced by the presence of a small amount of stearyl methacrylate (SM) as a co-monomer in hydroxyl ethyl acrylate (HEA). The compressive strength of the CMC-PEHA-DN hydrogel was found to be 280 times more than that of CMC-SN hydrogel, and the presence of SM in DN hydrogels showed better recovery after deformation. Cell viability studies showed the biocompatibility of DN hydrogels. The micro-structural analysis of DN xerogels by 3D X-ray Microtomography indicated the presence of oriented pores in size range of 30-40 µm. To the best of our knowledge, Microtomography was used for the first time to study the DN gels. These hydrogels can be used to develop implants that can withstand prolonged stress and expand the life span of implants.


Assuntos
Materiais Biocompatíveis , Hidrogéis , Acrilatos , Carboximetilcelulose Sódica , Força Compressiva
10.
PLoS One ; 16(9): e0257828, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34559849

RESUMO

Covered self-expandable metal stents (CSEMS) are often used for palliative endoscopic biliary drainage; however, the unobstructed period is limited because of sludge occlusion. The present study aimed to evaluate the biosafety of a novel poly(2-methoxyethyl acrylate)-coated CSEMS (PMEA-CSEMS) for sludge resistance and examine its biosafety in vivo. Using endoscopic retrograde cholangiopancreatography, we placed the PMEA-CSEMS into six normal porcine bile ducts and conventional CSEMS into three normal porcine bile ducts. We performed serological examination and undecalcified histological analysis at 1, 3, and 6 months during follow-up. In the bile ducts with PMEA-CSEMS or conventional CSEMS, we observed no increase in liver enzyme or inflammatory marker levels in the serological investigations and mild fibrosis but no inflammatory response in the histopathological analyses. Thus, we demonstrated the biosafety of PMEA-CSEMS in vivo.


Assuntos
Acrilatos/química , Ductos Biliares/cirurgia , Polímeros/química , Stents Metálicos Autoexpansíveis/efeitos adversos , Acrilatos/efeitos adversos , Animais , Análise Química do Sangue , Colangiopancreatografia Retrógrada Endoscópica , Feminino , Fígado/enzimologia , Modelos Animais , Polímeros/efeitos adversos , Sus scrofa
11.
Molecules ; 26(15)2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34361724

RESUMO

Orchids are rich treasure troves of various important phytomolecules. Among the various medicinal orchids, Ansellia africana stands out prominently in the preparing of various herbal medicines due to its high therapeutic importance. The nodal explants of A. africana were sampled from asymbiotically germinated seedlings on basal Murashige and Skoog (MS) medium and were micropropagated in MS medium supplemented with 3% sucrose and 10 µM meta topolin (mT) + 5 µM naphthalene acetic acid (NAA) +15 µM indole butyric acid (IBA) + 30 µM phloroglucinol (PG). In the present study, the essential oil was extracted by hydrodistillation and the oleoresins by the solvent extraction method from the micropropagated A. africana. The essential oil and the oleoresins were analysed by Gas Chromatography (GC) and GC/MS (Mass spectrometry). A total of 84 compounds were identified. The most predominant components among them were linoleic acid (18.42%), l-ascorbyl 2,6-dipalmitate (11.50%), linolenic acid (10.98%) and p-cresol (9.99%) in the essential oil; and eicosane (26.34%), n-butyl acetate (21.13%), heptadecane (16.48%) and 2-pentanone, 4-hydroxy-4-methyl (11.13%) were detected in the acetone extract; heptadecane (9.40%), heneicosane (9.45%), eicosane (6.40%), n-butyl acetate (14.34%) and styrene (22.20%) were identified and quantified in the ethyl acetate extract. The cytotoxic activity of essential oil and oleoresins of micropropagated A. africana was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide) assay on Vero cells compared to the standard drug doxorubicin chloride. The present research contains primary information about the therapeutic utility of the essential oil and oleoresins of A. africana with a promising future research potential of qualitative and quantitative improvement through synchronised use of biotechnological techniques.


Assuntos
Citotoxinas/isolamento & purificação , Óleos Voláteis/isolamento & purificação , Orchidaceae/química , Extratos Vegetais/isolamento & purificação , Plântula/química , Acrilatos/isolamento & purificação , Alcanos/isolamento & purificação , Animais , Ácido Ascórbico/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Cresóis/isolamento & purificação , Meios de Cultura/química , Meios de Cultura/farmacologia , Citotoxinas/farmacologia , Cromatografia Gasosa-Espectrometria de Massas , Hidroponia/métodos , Ácido Linoleico/isolamento & purificação , Extração Líquido-Líquido/métodos , Óleos Voláteis/farmacologia , Orchidaceae/metabolismo , Palmitatos/isolamento & purificação , Pentanóis/isolamento & purificação , Pentanonas/isolamento & purificação , Extratos Vegetais/farmacologia , Plantas Medicinais , Plântula/metabolismo , África do Sul , Estireno/isolamento & purificação , Células Vero , Ácido alfa-Linoleico/isolamento & purificação
12.
Food Res Int ; 147: 110532, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34399510

RESUMO

This study demonstrates a pH-responsive antibacterial film based on polyvinyl alcohol/poly (acrylic acid) incorporated with aminoethyl-phloretin (PVA/PAA-AEP) for intelligent food packaging. The thermal, mechanical, barrier and light transmittance properties of PVA/PAA are enhanced by PAA presence of ≤6%. The interactions between PVA and PAA were hydrogen and ester bonds. The pH-responsive characteristic is dependent on the protonation/deprotonation tendency of the carboxylic groups on PAA in acidic/alkaline environment. The PVA/PAA3 is selected for the incorporation of AEP and its pH-responsive swelling follows Ritger-Peppas and Schott second-order models. The AEP is hydrogen bonded with the matrix of PVA/PAA3 and the release of AEP is pH-responsive and a rate-limiting step following the First-order model. With pH decrease, the predominant release control was gradually changing from polymer relaxation to Fick diffusion. The PVA/PAA3-AEP films demonstrate AEP content dependent antioxidant and antimicrobial activities. Furthermore, the antibacterial efficiency against Listeria monocytogenes and Staphylococcus aureus is significantly better than Escherichia coli. The target film PVA/PAA3-AEP3 can effectively prolong the shelf-life of pork (TVB-N < 25 mg/100 g) by 4 days at 25 °C, suggesting its great potential in intelligent food packaging.


Assuntos
Anti-Infecciosos , Carne de Porco , Carne Vermelha , Acrilatos , Animais , Antibacterianos/farmacologia , Concentração de Íons de Hidrogênio , Floretina , Álcool de Polivinil , Suínos
13.
Anal Chim Acta ; 1176: 338763, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34399901

RESUMO

Monitoring of cysteine (Cys) is of significant importance for studying Cys-involved biological functions and clinically diagnosing Cys-related diseases. Recently, few fluorescent probes with two different reacting sites were reported to be capable of sensing different concentration ranges of Cys with distinct fluorescence signals, particularly suiting for bioimaging. However, due to relative sophisticated synthesis and moderate selectivity, the applications of these probes were still severely restricted. In this work, we proposed a novel probe design strategy by utilizing two same reacting groups, instead of two different reacting groups, to simplify the synthesis route and minimize the interference from competing species. Same reacting groups in a probe with different steric hindrances could exhibit different reactivities to Cys. This probe showed distinguishable fluorescence peak wavelengths towards low and high concentration ranges of Cys, giving green and blue emissions, respectively. Moreover, this probe was successfully applied for monitoring of Cys concentration in living cells. We believe this work provided a simpler strategy for dual-site fluorescent probes to sense difference concentration ranges of Cys, which may inspire more probe design in future.


Assuntos
Cisteína , Corantes Fluorescentes , Acrilatos , Fluorescência , Células HeLa , Homocisteína , Humanos
14.
Int J Pharm ; 607: 120991, 2021 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-34390811

RESUMO

Given that the use of some preservatives in cosmetics has been restricted, novel alternative preservatives are needed. The aim of this study was to characterize the physicochemical and antimicrobial properties of two polyelectrolyte complexes (EuB100 and EuB75Cl25), which were developed through hot melt extrusion (HME) using benzoic acid (BA) and Eudragit E100. Based on phase diagrams and an experimental statistical design, the solubility of the acid in the polymer and the HME conditions were established. Intermolecular interactions were evaluated through Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray powder diffraction (XRPD). Release behavior was determined for the systems. Antibacterial activity and ζ-potential were determined on Escherichia coli. FTIR revealed acid-base interaction, and XPS showed that the percentages of protonated nitrogen N1s were 13.5% for EuB100 and 20.3% for EuB75Cl25. The BA released showed a non-Fickian behavior, and a satisfactory antibacterial activity against E. coli was demonstrated at pH 6.9. The complexes modified ζ-potential, destabilizing the membrane functionality of E. coli. These complexes are potential antimicrobial preservatives with a greater spectrum of action, with bactericidal activity against E. coli in a wider pH range than uncomplexed BA, even at pH 6.9.


Assuntos
Anti-Infecciosos , Ácido Benzoico , Acrilatos , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Varredura Diferencial de Calorimetria , Composição de Medicamentos , Escherichia coli , Polímeros , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier
15.
Pediatr Dermatol ; 38(5): 1302-1304, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34418148

RESUMO

Continuous glucose monitoring (CGM) systems are of great value for patients with disorders of impaired glucose homeostasis, including glycogen storage diseases. We report on an 8-year-old girl with glycogen storage disease type 9b who developed severe allergic contact dermatitis to two different continuous glucose monitoring systems, FreeStyle® Libre and Dexcom® G6. Our case highlights the impact of sensitization for pediatric patients, the urgent need for open labeling of components by pharmaceutical and device manufacturers, and the need for avoidance of skin sensitizers in medical devices.


Assuntos
Dermatite Alérgica de Contato , Diabetes Mellitus Tipo 1 , Doença de Depósito de Glicogênio , Acrilatos , Glicemia , Automonitorização da Glicemia , Canfanos , Criança , Dermatite Alérgica de Contato/diagnóstico , Dermatite Alérgica de Contato/etiologia , Feminino , Humanos
17.
Sci Total Environ ; 798: 149171, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34329935

RESUMO

The global occurrence of organic UV filters in the marine environment is of increasing ecotoxicological concern. Here we assessed the toxicity of UV filters ensulizole and octocrylene in the blue mussels Mytilus edulis exposed to 10 or 100 µg l-1 of octocrylene and ensulizole for two weeks. An integrated battery of biochemical and molecular biomarkers related to xenobiotics metabolism and cellular toxicity (including oxidative stress, DNA damage, apoptosis, autophagy and inflammation) was used to assess the toxicity of these UV filters in the mussels. Octocrylene (but not ensulizole) accumulated in the mussel tissues during the waterborne exposures. Both studied UV filters induced sublethal toxic effects in M. edulis at the investigated concentrations. These effects involved induction of oxidative stress, genotoxicity (indicated by upregulation of DNA damage sensing and repair markers), upregulation of apoptosis and inflammation, and dysregulation of the xenobiotic biotransformation system. Octocrylene induced cellular stress in a concentration-dependent manner, whereas ensulizole appeared to be more toxic at the lower (10 µg l-1) studied concentration than at 100 µg l-1. The different concentration-dependence of sublethal effects and distinct toxicological profiles of ensulizole and octocrylene show that the environmental toxicity is not directly related to lipophilicity and bioaccumulation potential of these UV filters and demonstrate the importance of using bioassays for toxicity assessment of emerging pollutants in coastal marine ecosystems.


Assuntos
Mytilus edulis , Mytilus , Poluentes Químicos da Água , Acrilatos , Animais , Benzimidazóis , Biomarcadores , Ecossistema , Ácidos Sulfônicos , Protetores Solares/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
18.
Chemosphere ; 284: 131302, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34198063

RESUMO

Clogging generally happens to the leachate piping system, which poses a risk to the environment. A low surface energy nanocomposite is prepared to mitigate the cloggings, by adding the fluorinated acrylate polymer and hydrophobically modified nano-silica into high-density polyethylene (HDPE) substrate. The best addition of the fluorinated acrylate polymer and the nano-silica is given as 15% and 5%, to produce the composite with a low surface energy of 29.4 mJ/m2. Through the characterization of contact angle (CA), electrochemical corrosion, scanning electron microscopy (SEM) with energy dispersive X-ray spectrometer (EDS), atomic force microscope (AFM) and thermogravimetry (TG), the composite shows low wettability, good corrosion resistance and thermal stability. The surface hydrophobic property of the composite remains unchanged after being immersed in an acidic (pH = 2) and an alkaline (pH = 12) solution, indicating that the prepared composite has strong adaptability to the extreme environments. In addition, the composite shows better anti-scaling performance than that of the commercial high-density polyethylene (HDPE) and polyvinyl chloride (PVC) pipe materials by application of a dispensing leachate immersion test. The results provide insights into engineering practice for the design and manufacture of pipe materials for leachate collection and transport.


Assuntos
Polietileno , Poluentes Químicos da Água , Acrilatos , Polímeros de Fluorcarboneto , Dióxido de Silício
19.
ACS Biomater Sci Eng ; 7(8): 3709-3717, 2021 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-34328711

RESUMO

Improving hydrophilicity is a key factor for enhancing the biocompatibility of polymer surfaces. Nevertheless, previous studies have reported that poly(2-methoxyethyl acrylate) (PMEA) surfaces demonstrate markedly better biocompatibility than more hydrophilic poly(2-hydroxyethyl methacrylate) (PHEMA) surfaces. In this work, the origins of the excellent biocompatibility of the PMEA surface are investigated using molecular dynamics (MD) simulations of simplified binary mixtures of acrylate/methacrylate trimers and organic solvents, with n-nonane, 1,5-pentanediol, or 1-octanol serving as the probe organic foulants. The interactions between the acrylate/methacrylate trimers and solvent molecules were evaluated by calculating the radial distribution function (RDF), with the resulting curves indicating that the 2-methoxyethyl acrylate (MEA) trimer has a lower affinity for n-nonane molecules than the 2-hydroxyethyl methacrylate (HEMA) trimer. This result agrees with the experimental consensus that the biocompatibility of PMEA surfaces is better than that of PHEMA surfaces, supporting the hypothesis that the affinity between an acrylate/methacrylate trimer and a foulant molecule in a simplified binary mixture is a significant factor in determining a surface's antifouling properties. The RDF curves obtained for the other two solvent systems exhibited behavior that further highlighted the advantages of the PMEA surfaces as biocompatible polymers. In addition, the validity of employing the second virial coefficient (B2) as a predictor of antifouling properties was explored. The order of the B2 values of different binary mixtures indicated that the MEA trimers have the lowest affinities with n-nonane molecules, which confirms that although PMEA is more hydrophobic than PHEMA, it exhibits better biocompatibility. This analysis demonstrates that the MEA's weaker miscibility with nonpolar foulants contributes to the excellent biocompatibility of PMEA. Thus, B2 is a promising criterion for assessing the miscibility between acrylate/methacrylate materials and nonpolar organic foulants, which indicates the potential for predicting the antifouling properties of acrylate/methacrylate polymer materials by evaluating the value of B2.


Assuntos
Materiais Biocompatíveis , Simulação de Dinâmica Molecular , Acrilatos , Metacrilatos , Poli-Hidroxietil Metacrilato , Água
20.
Water Sci Technol ; 84(1): 237-250, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34280167

RESUMO

In this paper, the adsorptive performance of synthesized thiourea (TU) modified poly(acrylonitrile-co-acrylic acid) (TU-P(AN-co-AA)) polymeric adsorbent for capturing p-nitrophenol (PNP) from aqueous solution was investigated. TU-P(AN-co-AA) was synthesized via the redox polymerization method with acrylonitrile (AN) and acrylic acid (AA) as the monomers, then modified chemically with thiourea (TU). Characterization analysis with Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), elemental microanalysis for CHNS, zeta potential measurement, Brunauer-Emmett-Teller (BET) surface analysis and thermal analyses were carried out to determine the morphology and physico-chemical properties of the synthesized polymer. The characterization results indicated successful surface modification of polymer with TU. The performance of TU-P(AN-co-AA) for the removal of PNP was investigated under various experimental parameters (adsorbent dosage, initial adsorbate concentration, contact time and temperature). The results demonstrated that the Freundlich isotherm model and pseudo-second-order kinetic model best described the equilibrium and kinetic data, respectively. Thermodynamic studies showed that the uptake of PNP by TU-P(AN-co-AA) was spontaneous and exothermic in nature. The results of the regeneration studies suggested that the TU-P(AN-co-AA) polymer is a reusable adsorbent with great potential for removing PNP from wastewater.


Assuntos
Acrilonitrila , Poluentes Químicos da Água , Acrilatos , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Nitrofenóis , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Tioamidas , Poluentes Químicos da Água/análise
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