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1.
Med Hypotheses ; 143: 110203, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33017912

RESUMO

MicroRNAs (miRNAs) naturally occur in plants and all living organisms. They play an important role in gene regulation through binding toa specific region in open reading frames (ORFs) and/or untranslated regions (UTRs) to block the translation processes through either degrading or blocking mRNA resulting in knocking down or suppression of targeted genes. Plants and many organisms protect themselves from viruses through the production of miRNAs, which are complementary to 3UTR of viruses resulting in degrading the viral mRNA or block the translation on ribosomes. As pandemic, COVID-19, and its consequences on the global economy, we hypothesized a new approach for the treatment of COVID-19 paints. This approach includes designing a mix of miRNAs targeting several regions on COVID-19 open reading frame (ORF) and 3 UTR and suitable delivery system targeting respiratory system tissues. These synthesized miRNAs may be delivered to humansinnon-viral delivery systems such as liposomes like exosome (extracellular vesicle), polymer-based carriers, or inorganic nanoparticles, which are considered to be more suitable for human use.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/terapia , MicroRNAs/uso terapêutico , Pneumonia Viral/terapia , Regiões 3' não Traduzidas , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Sistemas de Liberação de Medicamentos , Exossomos , Regulação da Expressão Gênica , Técnicas de Transferência de Genes , Genoma Viral , Humanos , Lipossomos/química , Nanopartículas/química , Fases de Leitura Aberta , Pandemias , Pneumonia Viral/virologia , Polímeros/química
2.
Am J Dent ; 33(5): 243-247, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33017526

RESUMO

PURPOSE: Concurrently with the growing interest in CAD-CAM systems, several new materials of different chemical nature have become available. As an alternative to ceramics, numerous polymer-based materials have recently been proposed for permanent prosthetic restorations. Aim of this study was to test the CAD-CAM polymer-based materials available on the market, comparing mean flexural strength, Weibull characteristic strength and Weibull modulus. METHODS: Seven types of polymer-based blocks were tested: Lava Ultimate, 3M; Brilliant Crios, Coltene; Cerasmart, GC; Block HC, Shofu; Katana Avencia, Noritake; Grandio Blocs, Voco; Tetric CAD, and Ivoclar-Vivadent. Specimens were cut out from blocks, finished, polished, and tested in a three-point bending test apparatus until failure (n=30). Flexural strength, Weibull characteristic strength, and Weibull modulus were calculated. Flexural strength data were statistically analyzed. ANOVA on Ranks was applied, followed by the Dunn's test for post hoc comparisons (P= 0.05). RESULTS: Flexural strength values (MPa) were measured (mean±standard deviation). Different letters in parentheses label statistically significant differences: Grandio Blocs 266±24(a), Brilliant Crios 259±21(ab); Tetric CAD 254±15(ab); Katana Avencia 241±29(bc); Cerasmart 221±24(cd); Lava Ultimate 196±23(de); Block HC 139±10(e). All the tested materials had flexural strengths greater than 100 MPa, thereby satisfying the requirements of ISO standards for polymer-based materials. For all the tested materials the Weibull characteristic strength was greater than 100 MPa. Weibull modulus ranged between 21.20 (Tetric CAD) and 9.09 (Katana Avencia). CLINICAL SIGNIFICANCE: Even though all the CAD-CAM polymer-based materials marketed in blocks tested in the present study satisfy the requirements of ISO standard for polymer-based materials, their flexural resistance differs significantly. The data presented in the study may be helpful to clinicians for selecting the most appropriate materials for each clinical case.


Assuntos
Resistência à Flexão , Polímeros , Desenho Assistido por Computador , Materiais Dentários , Teste de Materiais
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4143-4146, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018910

RESUMO

In the past ten years, wearable electronics underwent tremendous growth. Undoubtedly, one of the fields that led this trend is represented by biomedical applications. In this field, wearable technologies can provide unique features such as the unobtrusive monitoring of biopotentials. Polymerbased electrodes developed for this purpose can take advantage of their seamless integration in the garments. However, the available solutions exhibit fragility in relation with the stretchability of the fabric, causing significant performance degradation.In this work, this problem is tackled by a novel deposition approach based on screen-printing technology. The electrodes are deposited onto the pre-stretched fabric to ensure the full functionality during common operating conditions. To this aim, a novel PEDOT:PSS conductive ink formulation and printing procedure were conceived. In order to prove the electrode performance for surface electromyography, we printed the electrodes directly onto a commercial stretchable polyester sleeve for sport applications. The electrodes allowed to reliably record the muscular activity of the forearm with performance comparable to that of commercial gelled Ag/AgCl electrodes. The obtained results suggest that the proposed approach can be valuably used in health and fitness applications.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Polímeros , Eletrodos , Eletromiografia
4.
Yakugaku Zasshi ; 140(10): 1243-1249, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32999203

RESUMO

Here the author describes the tumor-selective delivery of a fluorescence photosensitizing agent and an antitumor agent, based on the polymer effect of an N-(2-hydroxypropyl)methacrylamide (HPMA) based copolymer, by utilizing the enhanced permeability and retention (EPR) effect seen in solid tumors. Firstly, the tumor distribution of the photosensitizer, zinc-protoporphyrin IX (ZnPP), was significantly increased by conjugation with the HPMA polymer (P-ZnPP). The P-ZnPP suppressed tumor growth by local generation of cytotoxic singlet oxygen, and the tumor tissue was visualized by fluorescence upon light irradiation. Subsequently, a two-step mechanism for tumor selectivity was observed for the cytotoxic anthracycline, pirarubicin (THP), which conjugated the HPMA-based copolymer via a hydrazone bond (P-THP). The EPR-dependent accumulation of P-THP and the tumor-selective release of THP in the tumor tissues led to highly tumor-selective toxicity. Rapid cell uptake of THP compared to other anthracyclines, and deeper P-THP penetration of the tumor cell spheroid were attributed to the superior antitumor activity of P-THP. The molecular weight of P-THP affected its antitumor activity; oligomeric P-THP derivatives with higher molecular weights, DP-THP and SP-THP, showed even higher antitumor activity. P-THP was effective for both implanted tumor and autochthonous tumor models. These results indicate that nano-sized anticancer drugs based on polymer effect are promising clinical therapeutics.


Assuntos
Antineoplásicos , Sistemas de Liberação de Medicamentos , Desenvolvimento de Medicamentos/métodos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Fármacos Fotossensibilizantes , Polímeros , Protoporfirinas , Animais , Antraciclinas/química , Antraciclinas/metabolismo , Antineoplásicos/química , Antineoplásicos/metabolismo , Doxorrubicina/análogos & derivados , Doxorrubicina/química , Doxorrubicina/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Metacrilatos/química , Terapia de Alvo Molecular , Peso Molecular , Neoplasias/patologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/metabolismo , Protoporfirinas/química , Protoporfirinas/metabolismo
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3375-3378, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018728

RESUMO

Wirelessly powered implants are increasingly being developed as free-floating single-channel devices to interface with neurons directly at stimulation sites. In order to stimulate neurons in a manner that is safe to both the electrode and the surrounding tissue, charge accumulation over time needs to be avoided. The implementation of conventional charge balancing methods often leads to an increase in system complexity, power consumption or area, all of which are critical parameters in ultra-small wireless devices. The proposed charge balancing method described in this work, which relies on bipolar capacitive integrated electrodes, does not increase these parameters. The standalone wirelessly powered stimulating implant is implemented in a 130nm CMOS technology and measures 0.009 mm3.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Polímeros , Microeletrodos , Neurônios
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 3399-3402, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018733

RESUMO

Parylene-C has been used as a substrate and encapsulation material for many implantable medical devices. However, to ensure the flexibility required in some applications, minimize tissue reaction, and protect parylene from degradation in vivo an additional outmost layer of polydimethylsiloxane (PDMS) is desired. In such a scenario, the adhesion of PDMS to parylene is of critical importance to prevent early failure caused by delamination in the harsh environment of the human body. Towards this goal, we propose a method based on creating chemical covalent bonds using intermediate ceramic layers as adhesion promoters between PDMS and parylene.To evaluate our concept, we prepared three different sets of samples with PDMS on parylene without and with oxygen plasma treatment (the most commonly employed method to increase adhesion), and samples with our proposed ceramic intermediate layers of silicon carbide (SiC) and silicon dioxide (SiO2). The samples were soaked in phosphate-buffered saline (PBS) solution at room temperature and were inspected under an optical microscope. To investigate the adhesion property, cross-cut tape tests and peel tests were performed. The results showed a significant improvement of the adhesion and in-soak long-term performance of our proposed encapsulation stack compared with PDMS on parylene and PDMS on plasma-treated parylene. We aim to use the proposed solution to package bare silicon chips on active implants.


Assuntos
Dióxido de Silício , Xilenos , Cerâmica , Dimetilpolisiloxanos , Humanos , Polímeros
7.
Nat Commun ; 11(1): 4683, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943621

RESUMO

Wearable dry electrodes are needed for long-term biopotential recordings but are limited by their imperfect compliance with the skin, especially during body movements and sweat secretions, resulting in high interfacial impedance and motion artifacts. Herein, we report an intrinsically conductive polymer dry electrode with excellent self-adhesiveness, stretchability, and conductivity. It shows much lower skin-contact impedance and noise in static and dynamic measurement than the current dry electrodes and standard gel electrodes, enabling to acquire high-quality electrocardiogram (ECG), electromyogram (EMG) and electroencephalogram (EEG) signals in various conditions such as dry and wet skin and during body movement. Hence, this dry electrode can be used for long-term healthcare monitoring in complex daily conditions. We further investigated the capabilities of this electrode in a clinical setting and realized its ability to detect the arrhythmia features of atrial fibrillation accurately, and quantify muscle activity during deep tendon reflex testing and contraction against resistance.


Assuntos
Condutividade Elétrica , Epiderme , Monitorização Fisiológica/instrumentação , Movimento (Física) , Pele , Artefatos , Impedância Elétrica , Eletrocardiografia/instrumentação , Eletrocardiografia/métodos , Eletrodos , Eletroencefalografia/instrumentação , Eletroencefalografia/métodos , Eletromiografia/instrumentação , Eletromiografia/métodos , Desenho de Equipamento , Humanos , Monitorização Fisiológica/métodos , Polímeros/química , Sorbitol
8.
Nat Commun ; 11(1): 4848, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973166

RESUMO

Polydopamine (PDA) is a simple and versatile conformal coating material that has been proposed for a variety of uses; however in practice its performance is often hindered by poor mechanical properties and high roughness. Here, we show that blue-diode laser annealing dramatically improves mechanical performance and reduces roughness of PDA coatings. Laser-annealed PDA (LAPDA) was shown to be >100-fold more scratch resistant than pristine PDA and even better than hard inorganic substrates, which we attribute to partial graphitization and covalent coupling between PDA subunits during annealing. Moreover, laser annealing provides these benefits while preserving other attractive properties of PDA, as demonstrated by the superior biofouling resistance of antifouling polymer-grafted LAPDA compared to PDA modified with the same polymer. Our work suggests that laser annealing may allow the use of PDA in mechanically demanding applications previously considered inaccessible, without sacrificing the functional versatility that is so characteristic of PDA.


Assuntos
Indóis/química , Indóis/efeitos da radiação , Lasers , Polímeros/química , Polímeros/efeitos da radiação , Incrustação Biológica , Materiais Revestidos Biocompatíveis/química , Teste de Materiais , Propriedades de Superfície
9.
PLoS One ; 15(8): e0238322, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866178

RESUMO

Space-filling curves have been used for decades to study the folding principles of globular proteins, compact polymers, and chromatin. Formally, space-filling curves trace a single circuit through a set of points (x,y,z); informally, they correspond to a polymer melt. Although not quite a melt, the folding principles of Human chromatin are likened to the Hilbert curve: a type of space-filling curve. Hilbert-like curves in general make biologically compelling models of chromatin; in particular, they lack knots which facilitates chromatin folding, unfolding, and easy access to genes. Knot complexity has been intensely studied with the aid of Alexander polynomials; however, the approach does not generalize well to cases of more than one chromosome. Crossing complexity is an understudied alternative better suited for quantifying entanglement between chromosomes. Do Hilbert-like configurations limit crossing complexity between chromosomes? How does crossing complexity for Hilbert-like configurations compare to equilibrium configurations? To address these questions, we extend the Mansfield algorithm to enable sampling of Hilbert-like space filling curves on a simple cubic lattice. We use the extended algorithm to generate equilibrium, intermediate, and Hilbert-like configurational ensembles and compute crossing complexity between curves (chromosomes) in each configurational snapshot. Our main results are twofold: (a) Hilbert-like configurations limit entanglement between chromosomes and (b) Hilbert-like configurations do not limit entanglement in a model of S-phase DNA. Our second result is particularly surprising yet easily rationalized with a geometric argument. We explore ergodicity of the extended algorithm and discuss our results in the context of more sophisticated models of chromatin.


Assuntos
DNA/química , DNA/genética , Fase S/genética , Algoritmos , Cromatina/química , Cromatina/genética , Cromossomos/química , Cromossomos/genética , Humanos , Polímeros/química
10.
Braz Oral Res ; 34: e095, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901725

RESUMO

The purpose of this study was to synthesize dicalcium phosphate dihydrate (DCPD) particles functionalized with triethylene glycol dimethacrylate (TEGDMA) through different routes by varying the receptor solution: ammonium phosphate (AP groups) or calcium nitrate (CN groups) and the moment in which TEGDMA was incorporated: ab initio (ab) or at the end of dripping the solution (ap). Two syntheses were performed without adding TEGDMA (nf). The particles were characterized by X-ray diffractometry, true density (using a helium pycnometer), surface area, and scanning electron microscopy. A 20 vol% of DCPD particles from the D, E, and F groups was added to the resin matrix to determine the degree of conversion (DC), biaxial flexural strength (BFS), the flexural modulus (FM), and surface roughness after an abrasive challenge (RA). A group with silanized barium glass particles was tested as a control. The data were submitted to ANOVA/Tukey's test (DC, BFS, and RA), and the Kruskal-Wallis test (FM) (alpha = 0.05). BFS values varied between 83 and 142 MPa, and the CN_ab group presented a similar value (123 MPa) to the control group. FM values varied between 3.6 and 8.7 GPa (CN_ab and CN_nf groups, respectively), with a significant difference found only between these groups. RA did not result in significant differences. The use of calcium nitrate solution as a receptor, together with ab initio functionalization formed particles with larger surface areas. Higher BFS values were observed for the material containing DCPD particles with a higher surface area. In general, the DC, FM, and RA values were not affected by the variables studied.


Assuntos
Polímeros/química , Resinas Compostas , Resistência à Flexão
11.
Yakugaku Zasshi ; 140(9): 1175-1183, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32879249

RESUMO

The mock patches were prepared with novel acrylic polymers as adhesive layer where biphenyl-4-ylacetic acid (BAA) or 2-(2-fluorobiphenyl-4-yl) propanoic acid (FPA) was used as model active pharmaceutical ingredients (APIs). In addition, the mock patches were formulated with typical ester ingredients for transdermal dosage forms. The molecular state of the model APIs in the adhesive layer was observed by polarized microscope and microscopic Raman spectroscopy, which contains both conventional and low frequency (LF) region. Crystallization behavior would be depended on the interaction between API and polymers in the adhesive layer. In particular, LF Raman measurement was useful to discriminate API polymorphs. The pharmaceutical properties including dissolution and skin permeation of APIs were also evaluated for mock patches. The drug release and transdermal permeation were enhanced with the ester ingredients such as isopropyl myristate and diethyl sebacate due to their diffusion to the test solution or the skin stratum corneum as well as reducing the interaction between API and polymers. Further, the tack strength was not changed, but the peel strength was weakened by the additives. Thus, the adhesive properties were controllable by formulation with the additives. These findings could enable to evaluate the interaction between API and the polymers for adhesive layer and select the appropriate polymer and additives for used APIs when designing the drug products.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Polímeros , Adesivo Transdérmico , Adesividade , Administração Cutânea , Ácidos Decanoicos , Liberação Controlada de Fármacos , Miristatos , Fenilacetatos/administração & dosagem , Fenilacetatos/metabolismo , Propionatos/administração & dosagem , Propionatos/metabolismo , Absorção Cutânea , Solubilidade , Análise Espectral Raman
12.
Science ; 369(6509): 1305-1306, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32913091
13.
Ecotoxicol Environ Saf ; 205: 111318, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32979806

RESUMO

The retention of polyether sulfone (PES) and bisphenol A (BPA) in wastewater has received extensive attention. The effects of PES and BPA on the removal of organic matter by anaerobic granular sludge were investigated. We also analyzed the changes in the electron transport system and the effects on the composition of extracellular polymeric substances (EPS), as well as alternations of the microbial community in the anaerobic granular sludge. In the experimental groups which received BPA, the removal of the chemical oxygen demand (COD) were significantly suppressed, which an average removal efficiency of less than 65%, 30% lower than that of the control group. In the loosely-bound EPS (LB-EPS) excitation-emission matrix (EEM) spectra, the absorption peak of tryptophan disappeared when the BPA pollutants was added, which it was present in the control group without added pollutants. The addition of PES and BPA also affected protease, acetate kinase, and coenzyme F420 activities in the anaerobic granular sludge. Especially, the coenzyme F420 reduced from 0.0045 to 0.0017 µmol/L in the presence of PES and BPA. The relative abundance of Spirochaetes decreased in the presence of PES and BPA, while the relative abundance of Bacteroidetes increased from 12.98% to 22.87%. At the genus level, in the presence of PES and BPA, the relative abundance of Acinetobacter increased from 2.20% to 9.64% and Hydrogenophaga decreased sharply from 15.58% to 0.12%.


Assuntos
Compostos Benzidrílicos/análise , Microplásticos/análise , Fenóis/análise , Polímeros/química , Sulfonas/química , Eliminação de Resíduos Líquidos , Anaerobiose , Compostos Benzidrílicos/toxicidade , Análise da Demanda Biológica de Oxigênio , Matriz Extracelular de Substâncias Poliméricas , Microbiota/efeitos dos fármacos , Microplásticos/toxicidade , Fenóis/toxicidade , Plásticos , Esgotos/química , Águas Residuárias
14.
Waste Manag ; 118: 350-359, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32927388

RESUMO

It's an oversimplification to evaluate the reactivity of fly ash in geopolymerization using bulk elemental ratios like Si/Al. In this study, quantitative XRD by means of Rietveld refinement was employed to proportionate the mineral and glass phases of five fly ashes. The chemical environment of Si and Al in the fly ashes was investigated by 29Si and 27Al MAS NMR spectra. By counting the contributions of Al phase from mullite, the proportion of different coordination states of Al in the glass phase was speculated. The results reveal that the coordination number of Al is directly associated with the amount of alkali cations present in the glass phase for the most fly ashes, whereby higher the alkali content, the more four fold coordinated Al species are present in the system. Five and six fold coordinated Al as well as highly polymerized silicate species are also present in the glass structure of the fly ash. All these results point to an inherent inhomogeneous glass structure in fly ash. Despite that, a reactivity index derived from the NBO/T ratio (Non-Bridging Oxygen per Tetrahedral network former, e.g. SiO44-, AlO45-) modelled in a simplified glass setup, correlates well with the reaction heat of the geopolymers.


Assuntos
Cinza de Carvão , Polímeros , Álcalis , Espectroscopia de Ressonância Magnética , Difração de Raios X
15.
Waste Manag ; 118: 426-434, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32966947

RESUMO

This study concerns the evaluation of several properties/characteristics of 3D printed poly(lactic acid) (PLA) polymer and acrylonitrile-butadienestyrene (ABS) copolymer, recycled from food packages and car dashboards, respectively. The aim is to evaluate the potential of recycled polymers that are recovered from solid polymer waste (SPW) to be reused for functional components/parts for add-value applications. The study compared the performance of the recycled material with the obtained from the 3D printing of virgin polymer. The characterization was made considering the chemical, thermal and mechanical properties as well as surface roughness and wettability. Although the thermal characterization did not indicate significant variations between recycled and virgin material, the mechanical recycling process induced some chain scission in PLA. Consequently, the semi-crystalline polymer revealed losses of 33% both in tensile stress and flexural strength. On the contrary, recycled ABS did not show changes in the mechanical properties of the printed specimens. Both recycled polymers produced smoother surfaces with a decrease of the mean surface roughness between 55% and 65%. Considering the properties required by manufacturers of food containers and car dashboards, this study indicates that recycled materials can be reused for the same applications.


Assuntos
Acrilonitrila , Polímeros , Embalagem de Alimentos , Impressão Tridimensional , Reciclagem
16.
Nat Commun ; 11(1): 4536, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913189

RESUMO

Natural musculoskeletal systems have been widely recognized as an advanced robotic model for designing robust yet flexible microbots. However, the development of artificial musculoskeletal systems at micro-nanoscale currently remains a big challenge, since it requires precise assembly of two or more materials of distinct properties into complex 3D micro/nanostructures. In this study, we report femtosecond laser programmed artificial musculoskeletal systems for prototyping 3D microbots, using relatively stiff SU-8 as the skeleton and pH-responsive protein (bovine serum albumin, BSA) as the smart muscle. To realize the programmable integration of the two materials into a 3D configuration, a successive on-chip two-photon polymerization (TPP) strategy that enables structuring two photosensitive materials sequentially within a predesigned configuration was proposed. As a proof-of-concept, we demonstrate a pH-responsive spider microbot and a 3D smart micro-gripper that enables controllable grabbing and releasing. Our strategy provides a universal protocol for directly printing 3D microbots composed of multiple materials.


Assuntos
Biomimética/métodos , Compostos de Epóxi/efeitos da radiação , Fenômenos Fisiológicos Musculoesqueléticos , Polímeros/efeitos da radiação , Robótica/métodos , Soroalbumina Bovina/efeitos da radiação , Biomimética/instrumentação , Compostos de Epóxi/química , Hidrogéis/química , Hidrogéis/efeitos da radiação , Concentração de Íons de Hidrogênio , Lasers , Polimerização/efeitos da radiação , Polímeros/química , Impressão Tridimensional , Robótica/instrumentação , Soroalbumina Bovina/química
17.
Nat Commun ; 11(1): 4655, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938918

RESUMO

Purely organic room-temperature phosphorescence has attracted attention for bioimaging but can be quenched in aqueous systems. Here we report a water-soluble ultralong organic room-temperature phosphorescent supramolecular polymer by combining cucurbit[n]uril (CB[7], CB[8]) and hyaluronic acid (HA) as a tumor-targeting ligand conjugated to a 4-(4-bromophenyl)pyridin-1-ium bromide (BrBP) phosphor. The result shows that CB[7] mediated pseudorotaxane polymer CB[7]/HA-BrBP changes from small spherical aggregates to a linear array, whereas complexation with CB[8] results in biaxial pseudorotaxane polymer CB[8]/HA-BrBP which transforms to relatively large aggregates. Owing to the more stable 1:2 inclusion complex between CB[8] and BrBP and the multiple hydrogen bonds, this supramolecular polymer has ultralong purely organic RTP lifetime in water up to 4.33 ms with a quantum yield of 7.58%. Benefiting from the targeting property of HA, this supramolecular polymer is successfully applied for cancer cell targeted phosphorescence imaging of mitochondria.


Assuntos
Mitocôndrias/efeitos dos fármacos , Polímeros/química , Células A549 , Células HEK293 , Humanos , Ácido Hialurônico/química , Ligação de Hidrogênio , Medições Luminescentes , Microscopia Confocal , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Polímeros/metabolismo , Taxoides/química , Temperatura
18.
PLoS One ; 15(8): e0237271, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866161

RESUMO

Molecular separation of pharmaceutical contaminants from water has been recently of great interest to alleviate their detrimental impacts on environment and human well-being. As the novelty, this investigation aims to develop a mechanistic modeling approach and consequently its related CFD-based simulations to evaluate the molecular separation efficiency of ibuprofen (IP) and its metabolite 4-isobutylacetophenone (4-IBAP) from water inside a porous membrane contactor (PMC). For this purpose, octanol has been applied as an organic phase to extract IP and 4-IBAP from the aqueous solution due to high solubility of solutes in octanol. Finite element (FE) technique is used as a promising tool to simultaneously solve continuity and Navier-Stokes equations and their associated boundary conditions in tube, shell and porous membrane compartments of the PMC. The results demonstrated that the application of PMC and liquid-liquid extraction process can be significantly effective due to separating 51 and 54% of inlet IP and 4-IBAP molecules from aqueous solution, respectively. Moreover, the impact of various operational / functional parameters such as packing density, the number of fibrous membrane, the module length, the membrane porosity / tortuosity, and ultimately the aqueous solution flow rate on the molecular separation efficiency of IP and 4-IBAP is studied in more details.


Assuntos
Acetofenonas/isolamento & purificação , Anti-Inflamatórios não Esteroides/isolamento & purificação , Ibuprofeno/isolamento & purificação , Membranas Artificiais , Polímeros/química , Extração Líquido-Líquido/métodos , Octanóis/química , Porosidade , Solubilidade , Soluções
19.
Sci Total Environ ; 740: 139922, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-32927534

RESUMO

The aim of the present study was to determine the effect of a long-term (113 days) exposure to microplastics on the development and induction of endocrine, geno- and cytotoxic responses in early life stages of sea trout Salmo trutta. Microplastic particles (3000 µm) of three most commonly mass-produced polymers (polystyrene - PS, polyethylene terephthalate - PET and polyethylene - PE) were applied in environmentally realistic concentrations (0.1% of sediment dry weight) in a laboratory experiment imitating the natural environment, typical for sea trout spawning grounds. The exposure of the sea trout, from fertilized eggs to mobile yolk-sac larvae, to microplastics did not affect the hatching success (the survival of embryos), hatching rate and the incubation period. Microplastics of any tested polymer type also had no adverse effect on the larvae survival, growth rate and the rate of yolk sack absorption. Similarly, no changes in frequencies of detected cytotoxicity endpoints compared to the control group were recorded. Exposure to polymer particles induced however the formation of genotoxicity endpoints (nuclear buds, micronuclei and blebbed nuclei cells). The level of total genotoxicity (ΣGentox) in fish larvae erythrocytes increased significantly in the following sequence: PS > PET > PE. No significant changes in the whole body corticosterone, dehydrocorticosterone and cortisone concentrations due to exposure to microplastics were recorded, while cortisol was detected in larvae exposed to PS. Our results show that long-term, non-ingestion related exposure to microplastics does not affect development of S. trutta early life stages but may lead to genotoxic responses. PS seems to be the most hazardous among all polymers studied. This is the first study demonstrating non-ingestion related toxicity of microplastics to the early life stages of fish.


Assuntos
Plásticos , Poluentes Químicos da Água/análise , Animais , Microplásticos , Polímeros , Truta
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