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1.
Int J Nanomedicine ; 15: 1349-1361, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32184590

RESUMO

Background: Impaired wound healing might be associated with many issues, especially overactive of reactive oxygen species (ROS), deficiency of blood vessels and immature of epidermis. N-acetylcysteine (NAC), as an antioxidant, could solve these problems by inhibiting overreactive of ROS, promoting revascularization and accelerating re-epithelialization. How to deliver NAC in situ with a controllable releasing speed still remain a challenge. Materials and Methods: In this study, we combined collagen (Col) with N-acetylcysteine to perform the characteristics of sustained release and chemically crosslinked Col/NAC composite with polyamide (PA) nanofibers to enhance the mechanical property of collagen and fabricated this multi-layered scaffold (PA-Col/NAC scaffold). The physical properties of the scaffolds such as surface characteristics, water absorption and tensile modulus were tested. Meanwhile, the ability to promote wound healing in vitro and in vivo were investigated. Results: These scaffolds were porous and performed great water absorption. The PA-Col/NAC scaffold could sustainably release NAC for at least 14 days. After cell implantation, PA-Col/NAC scaffold showed better cell proliferation and cell migration than the other groups. In vivo, PA-Col/NAC scaffolds could promote wound healing best among all the groups. Conclusion: The multi-layered scaffolds could obviously accelerate the process of wound healing and exert better and prolonged effects.


Assuntos
Acetilcisteína/farmacologia , Colágeno/química , Depuradores de Radicais Livres/farmacologia , Nylons/química , Reepitelização/efeitos dos fármacos , Tecidos Suporte/química , Cicatrização/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Preparações de Ação Retardada , Masculino , Nanofibras/química , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo
2.
Chemosphere ; 242: 125287, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896200

RESUMO

A novel electrospun dual-responsive polyethersulfone-poly(dimethyl amino) ethyl methacrylate nanofibrous adsorbent was fabricated via electrospinning for the removal of Cu (II) from aqueous solution. Morphological, chemical, and dual-responsiveness of the composite nanofibrous adsorbent were characterized using scanning electron microscope equipped with energy dispersive x-ray, Fourier transform infrared, and UV-VIS spectrophotometer, respectively. The obtained uniform and bead-free nanofibers were then used for the removal of Cu (II) from aqueous solution. Results showed that the temperature-responsiveness of the nanofibers is dependent on the pH of the solution, as indicated by the decreasing lower critical solution temperature with increasing pH level. Temperature and pH offer a synergistic effect on the adsorption of Cu (II), with maximum adsorption observed at pH 6.5 at 55 °C. Kinetic, thermodynamic, and isotherm studies indicate that the adsorption of copper ions follows chemisorption and is thermodynamically favored at increasing temperature. From the Langmuir isotherm model, the obtained maximum adsorption capacity, qm, was 161.30 mg g-1 at 55 °C. From the desorption studies, results showed that the maximum desorption was observed at pH 3 at 25 °C. In conclusion, PES-PDMAEMA has the capability to adsorb and desorb Cu (II) by adjusting both pH and temperature, hence it can be considered as an efficient and economical adsorbent for heavy metals such Cu (II).


Assuntos
Cobre/análise , Metacrilatos/química , Nanofibras/química , Nylons/química , Polímeros/química , Sulfonas/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Íons , Cinética , Propriedades de Superfície , Temperatura , Termodinâmica
3.
Nat Commun ; 11(1): 509, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980642

RESUMO

The use of renewable feedstock is one of the twelve key principles of sustainable chemistry. Unfortunately, bio-based compounds often suffer from high production cost and low performance. To fully tap the potential of natural compounds it is important to utilize their functionalities that could make them superior compared to fossil-based resources. Here we show the conversion of (+)-3-carene, a by-product of the cellulose industry into ε-lactams from which polyamides. The lactams are selectively prepared in two diastereomeric configurations, leading to semi-crystalline or amorphous, transparent polymers that can compete with the thermal properties of commercial high-performance polyamides. Copolyamides with caprolactam and laurolactam exhibit an increased glass transition and amorphicity compared to the homopolyamides, potentially broadening the scope of standard polyamides. A four-step one-vessel monomer synthesis, applying chemo-enzymatic catalysis for the initial oxidation step, is established. The great potential of the polyamides is outlined.


Assuntos
Nylons/química , Cromatografia em Gel , Cristalização , Cristalografia por Raios X , Lactamas/química , Espectroscopia de Ressonância Magnética , Conformação Molecular , Nylons/síntese química , Polimerização , Estereoisomerismo , Temperatura
4.
J Chromatogr A ; 1609: 460446, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31420178

RESUMO

Two new copolymer-grafted silica stationary phases were prepared and employed in hydrophilic interaction chromatography (HILIC). 2-(Dimethylamino)ethyl methacrylate (DMAEMA) are copolymerized with itaconic acid (IA) and acrylic acid (AA) respectively, via thiol-ene click reaction on silica surface with deep eutectic solvents (DES) as new solvents. The obtained poly(DMAEMA-co-itaconic acid)-grafted silica (Sil-PDM-PIA) and poly(DMAEMA-co-acrylic acid)-grafted silica (Sil-PDM-PAA) were characterized by Fourier transform infrared spectroscopy, elemental analysis and solid-state 13C NMR spectra. Their hydrophilic interaction performances were evaluated by separating nucleosides, nucleobases, saccharides, and amino acids. Compared with previous reported poly(itaconic acid)-grafted silica (Sil-PIA) and poly(acrylic acid)-grafted silica (Sil-PAA) stationary phases, these two new copolymer-grafted silica performed higher selectivity and better separation for polar analytes in HILIC.


Assuntos
Cromatografia/métodos , Química Click/métodos , Interações Hidrofóbicas e Hidrofílicas , Polímeros/química , Dióxido de Silício/química , Solventes/química , Compostos de Sulfidrila/química , Acetonitrilos/química , Aminoácidos/isolamento & purificação , Entropia , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Metacrilatos/química , Nucleosídeos/isolamento & purificação , Nylons/química , Reprodutibilidade dos Testes , Sais/química , Espectroscopia de Infravermelho com Transformada de Fourier , Succinatos/química , Temperatura
5.
Chemosphere ; 238: 124691, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524626

RESUMO

In recent years, forward osmosis (FO) has represented numerous potential applications in safe water production. In this study, we improved the performance of FO thin film composite (TFC) membranes for the removal of trace organic compounds (TOrCs) by tuning the chemistry of its top active layer. The TFC membranes were synthesized by interfacial polymerization (IP) reaction between amine-containing monomers, e.g., meta-phenylene diamine (MPD) or para-phenylenediamine (PPD), and an acid chloride monomer, e.g., trimesoyl chloride (TMC). Owing to three free amine functionals over main core, melamine was used in the amine monomers solution to increase cross-linking among polyamide chains. Chemical and morphological characterization of the prepared membranes confirmed that melamine was successfully incorporated into the chemical structure of the top PA layer. Two agricultural toxic materials (atrazine and diazinon) were used to investigate the capability of the newly fabricated membranes in the removal of TOrCs. The obtained results showed that melamine-improved FO membranes provided higher atrazine and diazinon rejections in two different FO membrane configurations, including active layer facing feed solution (ALF) and active layer facing draw solution (ALD). The highest rejections of both diazinon (99.4%) and atrazine (97.3%) were achieved when the melamine modified MPD-based membrane served in ALF mode with 2 M NaCl as a draw solution.


Assuntos
Substâncias Húmicas/análise , Osmose/fisiologia , Purificação da Água/instrumentação , Purificação da Água/métodos , Atrazina/análise , Diazinon/análise , Membranas Artificiais , Nylons/química , Fenilenodiaminas/química , Polimerização , Cloreto de Sódio/química , Triazinas/química , Ácidos Tricarboxílicos/química , Água/química
6.
Anal Chim Acta ; 1093: 131-141, 2020 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-31735206

RESUMO

Simple and accurate detection of trace heavy metals in blood is very important. A novel dual-responsive electrochemical/fluorescent biosensor based on magnetic hyperbranched polyamide with heparin modification (MHPAM-H) for blood lead detection has been successfully developed. Upon conjugated with blood lead ions, dual-biosensor could not only display electrochemical signal but also fluorescence signal owing to the enriched amino groups, cavity structure, and good fluorescence properties of HPAM. Blood biocompatibility, construction of the dual-responsive biosensor, electrochemical/fluorescent detection of lead ions in water phase and blood condition, selectivity and stability of the dual-responsive biosensor were investigated in detail. The proposed dual-responsive biosensor displays good linear relationship (1.5 pM- 4.8 × 103 pM for electrochemical detection and 0.5 pM-4.8 × 103 pM for fluorescent detection) with low detection limit (4.4 pM for electrochemical detection and 1.0 pM for fluorescent detection) for blood lead, providing potential application for blood lead detection in the future.


Assuntos
Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Chumbo/sangue , Animais , Coagulação Sanguínea/efeitos dos fármacos , Fluorescência , Hemólise/efeitos dos fármacos , Heparina/química , Limite de Detecção , Nanopartículas de Magnetita/química , Nylons/química , Coelhos , Espectrometria de Fluorescência , Suínos
7.
Mater Sci Eng C Mater Biol Appl ; 106: 110245, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753357

RESUMO

The recent discovery of small interfering RNAs (siRNAs) has opened new avenues for designing personalized treatment options for various diseases. However, the therapeutic application of siRNAs has been confronted with many challenges because of short half-life in circulation, poor membrane penetration, difficulty in escaping from endosomes, and insufficient release into the cytosol. To overcome these challenges, we designed a diethylenetriamine (DETA)- and tetraethylenepentamine (TEPA)-modified polyamidoamine dendrimer generation 4.5 (PDG4.5), and characterized it using 1H nuclear magnetic resonance (NMR), 13C NMR, correlation spectroscopy (COSY), heteronuclear single-quantum correlation spectroscopy (HSQC), and Fourier transform infrared (FTIR) spectroscopy followed by conjugation with siRNA. The PDG4.5-DETA and PDG4.5-TEPA polyplexes exhibited spherical nanosize, ideal zeta potential, and effective siRNA binding ability, protected the siRNA from nuclease attack, and revealed less cytotoxicity of PDG4.5-DETA and PDG4.5-TEPA in HeLa cells. More importantly, the polyplexes also revealed good cellular internalization and facilitated translocation of the siRNA into the cytosol. Thus, PDG4.5-DETA and PDG4.5-TEPA can act as potential siRNA carriers in future medical and pharmaceutical applications.


Assuntos
Dendrímeros/química , Etilenodiaminas/química , Nylons/química , Poliaminas/química , RNA Interferente Pequeno/química , Portadores de Fármacos/química , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de Fourier
8.
Chemosphere ; 236: 124396, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31545199

RESUMO

Palygorskite (Pal) is a highly hydrophilic clay mineral with tubular structure and high aspect ratio, which facilitates the attachment of nanoparticles to their surface. It has become a promising new membrane preparation additive due to its lotus root like tubular structure, low price and environmental friendliness. Silver nanoparticles (AgNPs) have excellent antibacterial ability, and their incorporation into the membrane can significantly improve the bacteriostasis of the membrane. Herein, Pal was coated by polydopamine (PDA), which acted as both the adhesive and reducing agent for AgNPs. The incorporation of the Pal/Ag nanocomposite resulted in a thin polyamide (PA) layer with rough surface morphology, which facilitated the improvement of membrane permeability. Furthermore, the Pal's parallel tubes with a 0.37 × 0.63 nm2 cross-sectional area provided nanochannels allowing fast pass through of water molecules. The as-prepared TFN-7.5Pal/Ag membrane exhibited a permeate flux of 39.9 LMH at 16 bar, which was 1.6 times as high as that of the TFC membrane, accompanied with an acceptable NaCl rejection of 98.3%. Besides, antibacterial tests demonstrated that the TFN membrane presented excellent antibacterial performance against Escherichia coli (98.0%).


Assuntos
Anti-Infecciosos/farmacologia , Compostos de Magnésio/química , Membranas Artificiais , Nanopartículas Metálicas/química , Nanocompostos/química , Compostos de Silício/química , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/química , Incrustação Biológica/prevenção & controle , Escherichia coli/efeitos dos fármacos , Interações Hidrofóbicas e Hidrofílicas , Nylons/química , Permeabilidade , Prata/química , Água , Purificação da Água/instrumentação , Purificação da Água/métodos
9.
ACS Appl Mater Interfaces ; 11(36): 33033-33042, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31436947

RESUMO

Reverse osmosis (RO) is an emerging membrane technology for disinfection byproducts (DBPs) removal. However, the chlorine-resistance and DBPs removal performance of thin film composite (TFC) polyamide membranes should be simultaneously improved when used in chlorinated drinking water. This study was dedicated to synthesize a novel nanoparticle of ZIF-8 with carbon dots (CDs@ZIF-8) and then modify thin film nanocomposite (TFN) membranes to enhance their performance in removing four trihalomethanes (THMs), four haloacetonitriles (HANs), and two haloketones (HKs) in chlorinated drinking water. The fabricated CDs@ZIF-8 nanoparticles and TFN membranes were characterized by FESEM, AFM, XPS, water contact angle, membrane surface potential, and a three-dimensional excitation-emission matrix (EEM) to investigate the influences of CDs@ZIF-8 on TFN membranes. After chlorination, percentage reduction in salt rejection of the CDs@ZIF-8 TFN membranes was lower than that of the TFC membranes due to hydrogen bonding between CDs and polyamide, replacing amidic hydrogen with chlorine, rendering the membrane less susceptible to chlorine attack and enhancing chlorine-resistance. Results also showed that the rejection of DBPs in chlorinated drinking water by CDs@ZIF-8 TFN membranes was more than 95%. The large surface area and abundant oxygen-containing groups of CDs@ZIF-8 made the nanoparticle act as a nanocarbon filler with high adsorption capacity of DBPs. The enhanced performances of chlorine-resistance and DBPs removal by CDs@ZIF-8 TFN membranes determined in this study provided valuable insights on the DBPs control in chlorinated drinking water by RO membranes.


Assuntos
Cloro/análise , Desinfecção , Água Potável/química , Membranas Artificiais , Nanocompostos/química , Nylons/química , Pontos Quânticos/química , Compostos de Zinco/química , Carbono/química , Espectroscopia Fotoeletrônica , Pontos Quânticos/ultraestrutura , Espectrofotometria Ultravioleta , Poluentes Químicos da Água/isolamento & purificação
10.
Biochimie ; 167: 1-11, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31445072

RESUMO

Hairpin polyamides are synthetic small molecules that bind DNA minor groove sequence-selectively and, in many sequences, induce widening of the minor groove and compression of the major groove. The structural distortion of DNA caused by polyamides has enhanced our understanding of the regulation of DNA-binding proteins via polyamides. Polyamides have DNA binding affinities that are comparable to those proteins, therefore, can potentially be used as therapeutic agents to treat diseases caused by aberrant gene expression. In fact, many diseases are characterized by over- or under-expressed genes. PU.1 is a transcription factor that regulates many immune system genes. Aberrant expression of PU.1 has been associated with the development of acute myeloid leukemia (AML). We have, therefore, designed and synthesized ten hairpin polyamides to investigate their capacity in controlling the PU.1-DNA interaction. Our results showed that nine of the polyamides disrupt PU.1-DNA binding and the inhibition capacity strongly correlates with binding affinity. One molecule, FH1024, was observed forming a FH1024-PU.1-DNA ternary complex instead of inhibiting PU.1-DNA binding. This is the first report of a small molecule that is potentially a weak agonist that recruits PU.1 to DNA. This finding sheds light on the design of polyamides that exhibit novel regulatory mechanisms on protein-DNA binding.


Assuntos
DNA/metabolismo , Nylons/farmacologia , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Transativadores/antagonistas & inibidores , Animais , Sítios de Ligação/efeitos dos fármacos , DNA/química , Humanos , Camundongos , Nylons/síntese química , Nylons/química , Ligação Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/metabolismo
11.
Artif Cells Nanomed Biotechnol ; 47(1): 3094-3100, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31343278

RESUMO

To evaluate the long-term biological and clinical results of anterior cervical corpectomy and fusion (ACCF) with a synthesized nano-graphene oxide (nano-GO) loaded hydroxyapatite/polyamide (HAp/PA) strut in the implantation treatment of cervical reconstruction. Bio-ceramic Hydroxyapatite (HAp) combined with suitable polymer matrix is one of the furthermost naturally occurring biomaterial form for hard tissues and dental regeneration therapies due to their bone-like chemical compositional structure and biocompatibility similarity to native bone of the human body. In the present investigation, the development of nano-GO loaded HAp/PA composite strut for anterior cervical reform and fusion properties after corpectomy is studied. Forty patients who suffered from first or second level ACCF, treated with nano-GO loaded HAp/PA strut, were investigated. At final follow-up period, the fusion rate was 99%, and the subsidence value of the prepared strut was 5%. The results of cell viability and proliferation analyses indicated that the prepared nanocomposites did not exhibit non-cytotoxicity with the human cells. In summary, the satisfactory consequences in this research work designated that the nano-GO loaded HAp/PA strut was an active implant in the treatment of cervical reconstruction. Furthermore, the osteoconductive and osseointegration properties of the prepared struts need to be analyzed and optimized for future bio-medical usages.


Assuntos
Vértebras Cervicais/fisiologia , Vértebras Cervicais/cirurgia , Durapatita/química , Grafite/química , Nanocompostos/química , Nylons/química , Titânio/química , Adulto , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Linhagem Celular , Feminino , Humanos , Masculino , Teste de Materiais , Pessoa de Meia-Idade , Osseointegração/efeitos dos fármacos
12.
Opt Lett ; 44(13): 3366-3369, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31259962

RESUMO

Thermal diffusivity is one of the main parameters to characterize the thermo-physical properties of materials, and advances in its measurement technique will have significant impact on materials science and related applications. Here a photoacoustic (PA) thermorelaxation microscopy is proposed as a new noncontact method to measure the thermal diffusivity. By delivering co-focused heating/probing laser pulse pairs with tunable time delays, the sample's in situ thermal relaxation behavior after the heating pulse excitation can be photoacoustically monitored based on the temperature-dependent property of the Grueneisen parameter. We theoretically deduced the dependence of the obtained PA thermorelaxation time on the thermal diffusivity, and the results coincided well with simulations. The feasibility of this method was validated by various industrial and biological samples. This method provides a new strategy for high-resolution thermal diffusivity measurement with flexible measurement conditions, prefiguring great potential for material and biological applications.


Assuntos
Microscopia/métodos , Técnicas Fotoacústicas/métodos , Temperatura , Difusão Térmica , Dimetilpolisiloxanos/química , Nylons/química
13.
Environ Sci Pollut Res Int ; 26(26): 27372-27384, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31321725

RESUMO

In order to enhance the removal of Sb(III) in wastewater, hyperbranched polyamide-functionalized sodium alginate (HA@SA) microsphere was prepared by grafting of hyperbranched polyamide (HA) on the surface of sodium alginate (SA) microsphere. Adsorption properties of Sb(III) were investigated via static and dynamic adsorption tests. The cycling reusability of HA@SA microspheres was explored through adsorption-desorption tests. The changes of HA@SA microspheres before and after adsorption were characterized by FT-IR, SEM-EDS, and XPS. Results showed that the maximum Sb(III) adsorption capacity of HA@SA microspheres reached up to 195.7 mg/g, improved by 1.16 times in comparison with SA microspheres. The Sb(III) adsorption processes of HA@SA microspheres were depicted by pseudo-second-order kinetics and the Langmuir isotherm models with accuracy. It covered a homogeneous single-layer adsorption controlled by chemisorption along with exotherm spontaneously. After recycling for 8 times, the adsorption capacity of HA@SA microspheres still retained higher than 90% of the original value.


Assuntos
Alginatos/química , Antimônio/isolamento & purificação , Nylons/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Antimônio/química , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura , Microesferas , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de Tempo , Águas Residuárias/química , Poluentes Químicos da Água/química
14.
Food Chem ; 300: 125242, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31352285

RESUMO

New antioxidant polyamide was prepared by total immersion in active extract for 48 h. Its antioxidant performance was tested using DPPH (IC50 = 270 ±â€¯21 µg/g) and ORAC (1.52 µmol Trolox/g). In vivo study was done using fresh minced meat stored at 4 °C and analysed after 0, 6, 13, 19, 23 days. After 23 days metmyoglobin (MetMbBK = 31.3 ±â€¯2.9% and MetMbAOX = 25.9 ±â€¯0.8%), CIE L*a*b* (a*BK = 15.0 ±â€¯0.4 and a*AOX = 16.6 ±â€¯0.3) and TBARS (MDABK = 0.0060 ±â€¯0.0003 µg/g and MDAAOX = 0.0044 ±â€¯0.0002 µg/g) showed an improvement of meat shelf life. The results showed that this active film protected meat during 23 days. Migration study to food simulants was done by UPLC®-QqQ-MS and UPLC®-ESI-Q-TOF-MSE. A decrease of oligomers migration (for caprolactam n = 3: BK = 0.050 ±â€¯0.004 mg/Kg; AOX = 0.019 ±â€¯0.001 mg/Kg) was found. INDUSTRIAL RELEVANCE: Nowadays, food industry is focused on improving shelf life of products by controlling its lipid oxidation using natural antioxidants. The obtained results let us design a new active packaging based on natural antioxidants for extending the shelf life of fresh minced meat at industrial scale.


Assuntos
Antioxidantes/química , Embalagem de Alimentos/métodos , Carne , Nylons/química , Chá/química , Animais , Antioxidantes/farmacologia , Cromatografia Líquida de Alta Pressão , Conservação de Alimentos/métodos , Armazenamento de Alimentos/métodos , Metabolismo dos Lipídeos , Carne/análise , Metamioglobina/análise , Nylons/farmacologia , Oxirredução , Espectrometria de Massas por Ionização por Electrospray , Substâncias Reativas com Ácido Tiobarbitúrico/análise
15.
Chemosphere ; 233: 524-531, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31185336

RESUMO

Metal-organic frameworks (MOFs) addition into membranes is able to improve water flux without jeopardizing selectivity, which enhance the performance of reverse osmosis (RO) processes owing to its intrinsic physical and chemical properties, such as porosity structure and high compatibility with the polymer matrix. However, there were few studies about influences of nanoparticle size on MOFs-incorporated thin film nanocomposite (TFN) membranes. Here ZIF-8 particles with different average sizes (50, 150 and 400 nm) were synthesized and incorporated into organic monomer solution to fabricate TFN membranes for water desalination to investigate the membrane performance changed by nanomaterial size. Dispersion of ZIF-8 in selective layer during interfacial polymerization process was affected by particle size. The apparent morphology, roughness, and hydrophilicity of ZIF-8 modified TFN membranes were changed subsequently, which affected the water permeability, salt rejection and fouling resistance performance of the TFN membranes correspondingly. Our results showed that the TFN membrane comprising ZIF-8 with particle size of 50 nm had the best performance due to the highest dispersion in polyamide layer, revealing the importance of MOFs particle size in further investigation of MOFs-incorporated TFN membranes.


Assuntos
Filtração/métodos , Membranas Artificiais , Estruturas Metalorgânicas/química , Nanopartículas/química , Nylons/química , Purificação da Água/métodos , Zinco/química , Interações Hidrofóbicas e Hidrofílicas , Nanocompostos/química , Osmose , Tamanho da Partícula , Permeabilidade , Porosidade , Propriedades de Superfície
16.
Biomed Microdevices ; 21(3): 54, 2019 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-31203429

RESUMO

Aptamers have been widely used to recognize and capture their targets in sensitive detection applications, such as in detections of circulating tumor cells. In this study, we investigate the effects of different lengths of oligo-T spacers on surface tethered sgc8 aptamers and their target capturing performances. To achieve this, sgc8 aptamers were immobilized onto microfluidic channel surfaces via oligo-T spacers of different lengths, and the target capturing performances of these immobilized aptamers were studied using CCRF-CEM cells. We demonstrate that the capturing performances of the immobilized aptamers were significantly affected by steric hindrance. Our results also show that aptamers immobilized on surfaces via spacers of ten Ts demonstrated the best cell capturing performances; aptamers with either too short or too long oligo-T spacers showed reduced cell capturing performances. Therefore it can be concluded that spacer optimizations are critically important for surface tethered aptamers that are commonly used in microfluidic devices for sensitive target sensing and detections.


Assuntos
Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , Separação Celular/instrumentação , Dispositivos Lab-On-A-Chip , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Linhagem Celular Tumoral , Dimetilpolisiloxanos/química , Humanos , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Nylons/química , Propriedades de Superfície
17.
PLoS One ; 14(6): e0217441, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31166982

RESUMO

Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) is a promising quite new polymer with very interesting properties. The thermal degradation process of PDMAEMA was investigated. The polymer was heated at specific time intervals, then heating was stopped, and infrared analysis was performed to obtain information on the structure of the solid residue. The thermal degradation process has a two-stage character. The limit temperature for the first decomposition step was about 390°C, after which the second stage of sample decomposition began. The order of disintegration of the macromolecules was determined. Activation energy values for the thermal decomposition process have been calculated; they are 89.8 kJ/mol for the first stage and 17.7 kJ/mol for the second stage of the degradation process.


Assuntos
Temperatura Alta , Metacrilatos/química , Modelos Químicos , Nylons/química
18.
Photochem Photobiol Sci ; 18(8): 1923-1932, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31147667

RESUMO

Drug-resistant pathogens, particularly those that result in hospital acquired infections (HAIs), have emerged as a critical priority for the World Health Organization. To address the need for self-disinfecting materials to counter the threat posed by the transmission of these pathogens from surfaces to new hosts, here we investigated if a cationic BODIPY photosensitizer, embedded via electrospinning into nylon and polyacrylonitrile (PAN) nanofibers, was capable of inactivating both bacteria and viruses via antimicrobial photodynamic inactivation (aPDI). Materials characterization, including fiber morphology and the degree of photosensitizer loading, was assessed by scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and demonstrated that the materials were comprised of nanofibers (125-215 nm avg. diameter) that were thermostable to >300 °C. The antimicrobial potencies of the resultant Nylon-BODIPY(+) and PAN-BODIPY(+) nanofiber materials were evaluated against four strains of bacteria recognized by the World Health Organization as either critical or high priority pathogens: Gram-positive strains methicillin-resistant S. aureus (MRSA; ATCC BAA-44) and vancomycin-resistant E. faecium (VRE; ATCC BAA-2320), and Gram-negative strains multidrug-resistant A. baumannii (MDRAB; ATCC BAA-1605) and NDM-1 positive K. pneumoniae (KP; ATCC BAA-2146). Our results demonstrated the detection limit (99.9999%; 6 log units reduction in CFU mL-1) photodynamic inactivation of three strains upon illumination (30-60 min; 40-65 ± 5 mW cm-2; 400-700 nm): MRSA, VRE, and MDRAB, but only minimal inactivation (47-75%) of KP. Antiviral studies employing PAN-BODIPY(+) against vesicular stomatitis virus (VSV), a model enveloped virus, revealed complete inactivation. Taken together, the results demonstrate the potential for electrospun BODIPY(+)-embedded nanofiber materials as the basis for pathogen-specific anti-infective materials, even at low photosensitizer loadings.


Assuntos
Resinas Acrílicas/farmacologia , Antibacterianos/farmacologia , Compostos de Boro/farmacologia , Nylons/farmacologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Acinetobacter baumannii/efeitos dos fármacos , Resinas Acrílicas/química , Antibacterianos/química , Compostos de Boro/química , Klebsiella pneumoniae/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanofibras/química , Nylons/química , Tamanho da Partícula , Fármacos Fotossensibilizantes/química , Enterococos Resistentes à Vancomicina/efeitos dos fármacos
19.
J Chromatogr A ; 1602: 217-227, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31133424

RESUMO

The aim of this paper is to develop and validate a methodology with potential for routine analysis that allows a fast and easy quantification of 19 primary aromatic amines (PAAs) in acid simulant (3% (w/v) acetic acid aqueous) in food contact materials (FCM). The main reason for studying these amines was the fact that some of them have a carcinogenic factor according to toxicological studies. To validate the method, the parameters linearity, limit of detection (LOD) and limit of quantification (LOQ), precision and accuracy using an UPLC-MS/MS were evaluated. This study also analyzed 36 samples of kitchenware obtained from retail markets: 16 were made of polyamide (PA), one was made of polypropylene (PP) and 19 were made of silicone. The origins of samples were Brazil, China and Turkey. Eleven samples had levels of 4,4´-diaminodiphenylmethane higher than permitted by legislation and five samples showed values of aniline above the limit. Considering the Mood test for polyamides, there were significant differences between the samples from Brazil and China, as well as between the colors in the silicone samples. Regarding the polyamides, the Chinese samples showed higher amounts of PAAs than the Brazilian ones, being above that allowed by legislation. Three Chinese silicone samples presented values above the legislation limit. These were all from the same importer.


Assuntos
Aminas/análise , Técnicas de Química Analítica/métodos , Cromatografia Líquida , Utensílios de Alimentação e Culinária/normas , Contaminação de Alimentos/análise , Espectrometria de Massas em Tandem , Compostos de Anilina/análise , Brasil , Carcinógenos/análise , China , Contaminação de Alimentos/prevenção & controle , Limite de Detecção , Nylons/química , Polipropilenos/química
20.
Artif Cells Nanomed Biotechnol ; 47(1): 1888-1897, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31072140

RESUMO

Storage lesions in red blood cells (RBCs) hinder efficient circulation and tissue oxygenation. The absence of flow mechanics and gas exchange may contribute to this problem. To test if in vitro compensation of flow mechanics and gas exchange helps RBC recovery, three-dimensional polydimethylsiloxane (PDMS) porous structures were fabricated with a sugar mould, simulating lung alveoli. RBC suspensions were passed through the porous structure cyclically, simulating in vivo blood circulation. Acid-base indices, partial gas pressures, ions, glucose and RBC indices were analyzed. An atomic force microscope was used to investigate local mechanical properties of intact RBCs. RBCs suspensions that passed through the porous structures had a higher pH and oxygen partial pressure, and a lower potassium concentration and carbon dioxide partial pressure. Meantime they had better biochemical properties relative to static samples, namely, they exhibited a more homogenous distribution of Young's Modulus. RBCs that passed through a PDMS porous structure were healthier than static ones, giving hints to prevent RBC storage lesions.


Assuntos
Preservação de Sangue , Dimetilpolisiloxanos/química , Dimetilpolisiloxanos/farmacologia , Eritrócitos/efeitos dos fármacos , Gases/metabolismo , Hemorreologia/efeitos dos fármacos , Nylons/química , Nylons/farmacologia , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Módulo de Elasticidade/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/metabolismo , Glucose/metabolismo , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Masculino , Porosidade , Ratos , Ratos Wistar
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