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1.
Biomacromolecules ; 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31955566

RESUMO

Current therapy for liver failure and concomitant hyperbilirubinemia faces the challenge of poor hemocompatibility and bleeding risks associated with the anticoagulant injection. Herein, heparin-mimetic biomacromolecule (HepMBm) with a similar degree of sulfation and anticoagulant properties to heparin was synthesized by imitating the structure of natural biomacromolecule heparin. Then HepMBm was used to prepare nanocomposite spheres based on reduced graphene oxide (rGO). The formation of a dual-network structure in the spheres endowed the spheres with improved dimensional stability. The proposed spheres exhibited outstanding blood compatibilities and excellent self-anticoagulant properties. The bilirubin adsorption experiments and whole blood bilirubin removal assay indicated that the spheres exhibited high bilirubin removal capability from whole blood (The removal ratio was 99.69%.). The spheres open new routes for a therapeutic strategy without a plasma separation system and heparin pump, which may be a step toward a lightweight wearable artificial liver.

2.
Int J Biol Macromol ; 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31783078

RESUMO

Adsorbents are usually used to remove uremic toxins for blood purification. However, the removal of urea is still an intractable problem, since no effective material has been found for urea removal by physical adsorption. Here, urease immobilized graphene oxide core@shell heparin-mimicking polymer (U-GO-HMP) beads were designed, which exhibited good urea removal ability with a removal amount of about 635 mg/g and a removal ratio of about 80% from urea solution. In addition, urea could be removed from collected dialysate and the removal ratio could reach 60% within 480 min. Beyond that, the U-GO-HMP beads also showed good reusability with sustainable relative activity after 5 cycles. Furthermore, the U-GO-HMP beads exhibited good blood compatibility with low hemolysis ratio, suppressed complement activation and contact activation, as well as increased clotting times. It is worthy believing that the U-GO-HMP beads may have great potential in the field of blood purification for urea removal.

3.
J Colloid Interface Sci ; 556: 492-502, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31473539

RESUMO

Given the complexity of pollutants in wastewater, development of facile and effective multifunctional materials, which can not only kill bacteria but also remove dyes from wastewater, is in high demand. Herein, a facile strategy for the preparation of positively-charged nanofibrous membranes (NFMs) is reported via the combination of electrospinning and in-situ cross-linked polymerization of poly ([2-(methacryloyloxy)-ethyl] trimethyl ammonium chloride) (PMETAC) in poly (ether sulfone) (PES) solution. The quaternary ammonium salt polymer of PMETAC enabled the NFMs with positive charge to kill bacteria and remove anionic dyes. The antibacterial tests including agar plate counting and live/dead staining indicate that the NFMs show strong antibacterial ability with bacterial killing ratios of nearly 99% for both Escherichia coli and Staphylococcus aureus, as well as remarkable recyclability towards killing bacteria. The dyes adsorption experiments show that the NFMs exhibit high adsorption capacity for anionic dyes up to 208 mg g-1 for Congo Red (CR) and good reusability toward CR. Impressively, the membrane adsorption column test indicates that the CR dye removal ratio is up to 100% for the first time, and that is still as high as 96.5% for the third time with a fresh dye solution. Given the above advantages, such fascinating NFMs may provide new perspectives in the exploitation of multifunctional membrane materials for complex water remediation.


Assuntos
Antibacterianos/química , Corantes/química , Escherichia coli/crescimento & desenvolvimento , Membranas Artificiais , Nanofibras/química , Polímeros/química , Staphylococcus aureus/crescimento & desenvolvimento , Sulfonas/química , Águas Residuárias , Adsorção , Águas Residuárias/química , Águas Residuárias/microbiologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-31411370

RESUMO

The current challenge for polymersomes is to prepare amphiphilic block polymers with not only well-defined molecular weight, but also precisely high-order multiblock structure in terms of the distribution of monomeric units along the chain. Here, we describe a synthesis of temperature-responsive polymersomes with precisely defined membrane structures using high-precision amphiphilic multiblock polymer via aqueous single electron transfer living radical polymerization (SET-LRP) in which poly(ethylene glycol) (PEG) macromolecules are used as initiators. We develop a one-pot, rapid and multistep sequential polymerization process with yields >99% within 30 min for each block, giving access to a wide range of high-precision multiblock polymers with very narrow molecular weight distributions (Ð ≤ 1.14). Synthesized multiblock polymers are used to form nano-sized polymersomes which are highly promising as smart carriers for high loading and triggered release of biopharmaceutics such as pharmaceutical proteins and peptides. This synthesis approach is environmentally friendly, fully translation and thus represents a significant advance in the design and synthesis of a new generation of polymer nanomaterials with precisely defined structures, which is highly attractive for applications in nanotechnology.

5.
Colloids Surf B Biointerfaces ; 181: 918-926, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31382341

RESUMO

Postoperative adhesion may form as the result of a complicated fibrosis and inflammatory response, thus leads to a series of complications or increases the risk of surgery failure. Herein, we prepared poly (lactic-co-glycolic acid)-graft-polyvinylpyrrolidone/polyiodide (PLGA-g-PVP/I) electrospun fibrous membranes to prevent postoperative adhesion and infection formation. Firstly, hydrophilic PVP molecules were grafted on the surface of PLGA powders by gamma ray, and then iodine ions were coordinated with the grafted PVP. Subsequently, PLGA-g-PVP/I fibrous membranes were prepared by electrospinning. The PLGA-g-PVP/I membranes were analyzed via UV-vis, FTIR, Raman, and XPS. The formed polyiodide endowed the membranes with sustained antibacterial activity. The antimicrobial property of PLGA-g-PVP/I membranes was ascribed to the synergistic effect of intracellular ROS production and glutathione oxidation. Furthermore, the prevention efficacy of postoperative abdominal adhesion from the PLGA-g-PVP/I composite membranes was characterized in a rat model of sidewall defect-cecum abrasion. The results demonstrated that the PLGA-g-PVP/I fibrous membranes could prevent the postoperative abdominal adhesion effectively. Therefore, to endow the PLGA-g-PVP/I electrospun fibrous membranes with durable antibacterial property may be a promising strategy towards an anti-bacterial and anti-adhesion system for commercial and clinical uses.


Assuntos
Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Escherichia coli/efeitos dos fármacos , Ácido Periódico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Povidona/química , Animais , Antibacterianos/química , Materiais Biocompatíveis/química , Proliferação de Células/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Estresse Oxidativo/efeitos dos fármacos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Ratos , Raios Ultravioleta
6.
J Colloid Interface Sci ; 533: 526-538, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30179831

RESUMO

The adsorbents with high adsorption capacity are in urgent demand for water treatment because of the global freshwater crisis. In this work, the copolymer of acrylic acid and methyl methacrylate was synthesized at first, and subsequently blended with polyethersulfone (PES) with different mass ratios to prepare functionalized PES nanofibrous membranes via one-step electrospinning method. Benefiting from the abundant carboxyl groups, as well as the large specific surface area and high porosity, the nanofibrous membranes exhibited a maximum adsorption capacity of 2257.88 mg g-1 for methylene blue (MB) dyes, which was among the largest adsorption amount of those previously reported adsorbents. In addition, the adsorption process was systematically investigated under various conditions, including pH, initial MB concentrations and contact time. Meanwhile, the pseudo-second-order model and Langmuir isotherm model was very suitable to describe the adsorption kinetics and isotherm, respectively. Moreover, the nanofibrous membranes also exhibited excellent recyclability (81.45% after 5 cycles), high filtration-purification efficiency (above 99%, at a high flux of 100 mL min-1) and selective adsorption and separation abilities. These excellent performances endow the nanofibrous membranes with promising potential applications for dye wastewater treatment.

7.
J Colloid Interface Sci ; 538: 648-659, 2019 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-30572229

RESUMO

Multifunctional materials, which can effectively and simultaneously remove various water-soluble contaminants like dyes and heavy metal ions, and separate oil from water, are urgent to meet increasing challenges on wastewater remediation. Herein, a cross-linked poly (acrylic acid) (PAA) modified poly (ether sulfone) nanofibrous membrane (NFM) was fabricated by a facile in-situ pre-reaction followed by electrospinning. The as-prepared NFM showed excellent hydrophilicity and underwater lipophobicity, therefore expressed excellent water permeability with high water flux (about 5142 L m2 h-1). As a result, under solely driven by gravity, the NFM was capable to separate emulsified oil/water emulsion and a wide range of oil/water mixtures. Moreover, repeating separation tests indicated that the NFM had great long-term sustainability even after ten separation cycles. In addition, due to the introduction of PAA and the large surface-to-volume ratio, the NFM also expressed rapid adsorption capacity for cationic dyes as well as heavy metal ions; thus could simultaneously remove these contaminants during the oil/water separation process. Furthermore, the NFM could be also decorated by Ag NPs to endow the membranes with remarkable antibacterial ability against both E. coli and S. aureus. Our findings strongly suggested that the multifunctional NFM may have great potential in treating complicated wastewater.

8.
Langmuir ; 35(5): 1430-1439, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30056716

RESUMO

Although abundant works have been developed in mussel-inspired antifouling coatings, most of them suffer from poor chemical stability, especially in a strongly alkaline environment. Herein, we report a robust one-step mussel-inspired method to construct a highly chemical stable and excellent antibiofouling membrane surface coating with a highly efficient codeposition of polydopamine (PDA) with zwitterionic polymer. In the study, PDA and polyethylenimine-quaternized derivative (PEI-S) are codeposited on the surface of poly(ether sulfone) (PES) ultrafiltration membrane in water at room temperature. In contrast to individual PDA coating, the obtained PDA/PEI-S coating exhibits excellent chemical stability even in a strongly alkaline environment owing to the cross-linking and unexpected cation-π interaction between the PEI-S and PDA. Thanks to the introduction of PEI-S, systematic protein adsorption tests and bacteria adhesion experiments demonstrated that the surfaces could prevent bovine serum fibrinogen and lysozyme adsorption and could reduce Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli adhesion. Benefiting from the versatile functionality of PDA, the proposed strategy is not limited to PES membrane surface but also others such as poly(ethylene terephthalate) sheets and commercial polypropylene microfiltration membranes. Overall, this work enriches the exploration of a remarkable coating with enhanced stability and excellent antifouling property via a facile, robust, and material-independent approach to modifying the membrane surface.

9.
J Colloid Interface Sci ; 510: 308-317, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28957747

RESUMO

Development of antibacterial membranes is strongly desired for biomedical applications. Herein, we integrated antifouling and bactericidal properties on polymeric membrane surface via Schiff-based layer-by-layer (LbL) assembly. Zwitterionic polymers bearing plentiful amino groups (based on polyethylenimine (PEI) and sulfobetaine methacrylate (SBMA), and termed as PEI-SBMA) were utilized to prepare an antifouling membrane surface; then robust wide-spectrum bactericidal Ag nanoparticles (Ag NPs) were in situ generated on the surface. The as-prepared zwitterionic polymer surface showed excellent resistance to protein adsorption and bacterial adhesion. The Ag NPs could be tightly and uniformly distributed on the membrane surface by the chelation of PEI-SBMA, and endowed the membrane with bactericidal activity. Meanwhile, the Ag NPs loaded membrane could effectively resist bacterial attachment for a long time, even though the bactericidal activity lost. The proposed bactericidal and antifouling membrane was flexible, versatile and could be large-scale preparation; and this strategy would have great potential to be widely used to avoid undesired bacterial contamination of biomedical implants or biological devices.


Assuntos
Antibacterianos/química , Membranas Artificiais , Nanopartículas Metálicas/química , Metacrilatos/química , Polietilenoimina/química , Bases de Schiff/química , Prata/química , Adsorção , Antibacterianos/farmacologia , Aderência Bacteriana , Incrustação Biológica , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Humanos , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Propriedades de Superfície
10.
Sensors (Basel) ; 17(12)2017 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-29168772

RESUMO

We review some advances of the particle filtering (PF) algorithm that have been achieved in the last decade in the context of target tracking, with regard to either a single target or multiple targets in the presence of false or missing data. The first part of our review is on remarkable achievements that have been made for the single-target PF from several aspects including importance proposal, computing efficiency, particle degeneracy/impoverishment and constrained/multi-modal systems. The second part of our review is on analyzing the intractable challenges raised within the general multitarget (multi-sensor) tracking due to random target birth and termination, false alarm, misdetection, measurement-to-track (M2T) uncertainty and track uncertainty. The mainstream multitarget PF approaches consist of two main classes, one based on M2T association approaches and the other not such as the finite set statistics-based PF. In either case, significant challenges remain due to unknown tracking scenarios and integrated tracking management.

11.
ACS Appl Mater Interfaces ; 9(37): 32237-32247, 2017 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-28857540

RESUMO

Novel anion-responsive "intelligent" membranes with functional gates are fabricated by filling polyethersulfone microporous membranes with poly(ionic liquid)s (PILs) gels. The wetting properties of the PILs could be controlled by changing their counteranions (CAs), and thus, the filled PILs gel gates in the membrane pores could spontaneously switch from the "closed" state to the "open" one by recognizing the hydrophilic CAs in the environment and vice versa. As a result, the fluxes of the "intelligent" membranes could be tuned from a very low level (0 mL/m2·mmHg for Cl-, Br-, and BF4-) to a relatively high one (430 mL/m2·mmHg for TFSI). The anion-responsive gating behavior of the PILs filled membranes is fast, reversible, and reproducible. In addition, the "intelligent" membranes are sensitive to contact time and ion concentrations of the hydrophobic CA species. The proposed anion-responsive "intelligent" membranes are highly attractive for ion-recognizable chemical/biomedical separations and purifications.

12.
Mol Med Rep ; 16(3): 2856-2862, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28677787

RESUMO

Forkhead box L2 (FOXL2) is a transcription factor, which is involved in blepharophimosis, ptosis, and epicanthus in versus syndrome (BPES), premature ovarian failure (POF), as well as almost all stages of ovarian development and function. FOXL2 has various target genes, which are implicated in numerous processes, including sex determination, cell cycle regulation and apoptosis and stress response regulation in mammals. However, studies regarding the upstream regulation of FOXL2 are limited. In the present study, the promoter of FOXL2 was successfully cloned and registered in Gen Bank, and a dual luciferase reporter (DLR) analysis demonstrated that the luciferase activity was significantly induced by the promoter of FOXL2. Subsequently, bioinformatics analysis indicated that FOXL2 may be regulated by STAT3, and this was confirmed by a DLR analysis and western blotting, using STAT3 inhibitors. Further study using real­time cellular analysis indicated that the viability of He La cells was markedly suppressed by STAT3 inhibitors. The present study demonstrated novel findings regarding the upstream regulation of FOXL2 expression and provide a new perspective for future studies in the field.


Assuntos
Proteína Forkhead Box L2/genética , Regulação da Expressão Gênica , Regiões Promotoras Genéticas , Fator de Transcrição STAT3/metabolismo , Proliferação de Células/efeitos dos fármacos , Clonagem Molecular/métodos , Células HeLa , Humanos , Plasmídeos/genética , Fator de Transcrição STAT3/antagonistas & inibidores
13.
Mater Sci Eng C Mater Biol Appl ; 78: 1035-1045, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28575937

RESUMO

In this study, new kinds of heparin-mimicking polyurethanes (PUs) were fabricated conveniently in the mixed solution of dimethyl sulfoxide (DMSO) and water, reducing the usage of organic solvent. Functional groups of SO3H and/or COOH were introduced into PUs with various ratios of SO3H to COOH. The PUs were then blended with polyethersulfone (PES) to fabricate heparin-mimicking modified PES membranes by a phase inversion technique. Then, the microstructures, zeta potentials, water contact angles (WCA) and protein adsorptions of the membranes were characterized. Comparing with pristine PES membrane, the modified membranes showed changed cross-sectional morphology, lowered zeta potentials and decreased water contact angles, revealing that the hydrophilicity and anti-fouling properties were improved. The modified membranes also showed prolonged clotting tines (APTTs) and suppressed platelet adhesion, revealing that the anticoagulant properties increased. The results of complement activation, contact activation and platelet activation further implied that the modified membranes had good blood compatibility. In addition, the cells on the membranes showed good morphology with the introduction of the PUs. With the increase of the ratio of SO3H to COOH, the hydrophilicity, the blood compatibility as well as the cytocompatibility increased, implying that the SO3H groups could improve the hemocompatibility of the membranes more effectively than COOH groups. While the membranes containing more COOH groups had better antifouling properties of BSA and BFG. Therefore, the hemocompatibility for the heparin-mimicking membranes could be tuned by controlling the ratios of SO3H to COOH. The PES/PU composite membranes might have great potential to be used in the field of blood purification.


Assuntos
Poliuretanos/química , Materiais Biocompatíveis , Estudos Transversais , Heparina , Membranas Artificiais , Polímeros , Sulfonas
14.
Int J Biol Macromol ; 98: 1-11, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28130129

RESUMO

In the present study, novel heparin-mimetic polyurethane hydrogels were prepared by introducing chemical crosslinked sulfated konjac glucomannan (SKGM). Scanning electron microscopy (SEM) results indicated that the introduction of SKGM and the increase of the molecular weight of diol segments could enlarge the pore sizes of the hydrogels. The swelling behavior corresponded with the SEM results, and the hydrogels could absorb more water after the modification. The modification also led to an improvement in the mechanical property. Meanwhile, the SKGM and the modified polyurethane hydrogels showed excellent hemocompatibility. The thromboplastin time of SKGM could reach up to 182.9s. Gentamycin sulfate (GS) was used as a model drug to be loaded into the hydrogels, and the loading amount was increased ca. 50% after the introduction of SKGM, thus resulting in high bactericidal efficiency. The results indicated that the introduction of SKGM and the alternation in the diol's molecular weight bestowed polyurethane hydrogels with promising properties of integrated blood-compatibility, mechanical properties and drug loading-releasing behavior. Therefore, the heparin-mimetic multifunctional polyurethane hydrogels have great potential to be used in biomedical applications.


Assuntos
Portadores de Fármacos/química , Liberação Controlada de Fármacos , Heparina/metabolismo , Hidrogéis/química , Fenômenos Mecânicos , Poliuretanos/química , Poliuretanos/farmacologia , Adulto , Anticoagulantes/química , Anticoagulantes/farmacologia , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Gentamicinas/química , Gentamicinas/farmacologia , Hemólise/efeitos dos fármacos , Humanos , Masculino , Mananas/química , Teste de Materiais , Sulfatos/química
15.
J Colloid Interface Sci ; 485: 39-50, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27643469

RESUMO

The removal of toxins is important due to the damage to aquatic environment. In this work, a facile and green approach based on mussel-inspired coatings was used to fabricate amino-coated particles via the reaction between amine and catechol, using hexanediamine as the representative amine. The particles were characterized by Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), thermo gravimetric analysis (TGA), and scanning electron microscopy (SEM). The particles showed selective adsorption capability to Congo red (CR) and the adsorption process fitted the pseudo-second-order model, the intraparticle diffusion model, the Langmuir isotherm, the Freundlich isotherm and the Sips isotherm well. Furthermore, this approach was verified to have applicability to various amines such as diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA), and the amino-coated particles exhibited diverse adsorption capacities to CR, Cu2+ and bilirubin. Considering that the approach is easy to operate and the whole preparation process is in an aqueous solution, it is believed that the facile, green and economical approach has great potential to prepare particles for wastewater treatment.

16.
Biomacromolecules ; 17(12): 4011-4020, 2016 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-27936718

RESUMO

The aim of this study was to create heparin-like chitosan hydrogels (HLCHs) for blood purification. Herein, we prepared two heparin-like chitosans (HLCSs) with various carboxymethyl and sulfate groups, followed by a cross-linking reaction with glutaraldehyde. The synthetic chitosan derivatives were characterized by X-ray photoelectron spectroscopy, gel permeation chromatography, FTIR and NMR. The average sulfonation degrees of two HLCSs were 0.69 and 0.94 per sugar unit, respectively. The swelling ratio of the HLCH could reach up to 4800%, and the HLCHs remained a well-defined shape and stable below 170 °C. Moreover, the activated partial thromboplastin time and thrombin time results indicated that both of the HLCSs and their hydrogels exhibited excellent thrombus inhibition property. Furthermore, the contact activation and complement activation results also proved that the hydrogels possessed good blood compatibility and had the potential to be used as blood-contacting materials.


Assuntos
Materiais Biocompatíveis/química , Coagulação Sanguínea , Quitosana/química , Ativação do Complemento , Heparina/química , Hidrogéis/química , Humanos , Concentração Osmolar , Tempo de Coagulação do Sangue Total
17.
Biomater Sci ; 4(10): 1431-40, 2016 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-27526645

RESUMO

In this study, a new kind of hemocompatible and antibacterial dual-layered polymeric membrane was fabricated by coating a top layer of graphene oxide and a sulfonated polyanion co-doped hydrogel thin film (GO-SPHF) on a bottom membrane substrate. After a two-step spin-coating of casting solutions on glass plates, dual-layered membranes were obtained by a liquid-liquid phase inversion method. The GO-SPHF composite polyethersulfone (PES) membranes (PES/GO-SPHF) showed top layers with obviously large porous structures. The chemical composition tests indicated that there were abundant hydrophilic groups enriched on the membrane surface. The examination of membrane mechanical properties indicated that the composite membranes exhibited only slightly decreased performance compared to pristine PES membranes. Moreover, to validate the potential applications of this novel dual-layered membrane in diverse fields, we tested the hemocompatibility and antibacterial activity of the membranes, respectively. Notably, the PES/GO-SPHF membranes showed highly improved in vitro hemocompatibility, such as good anti-coagulant activity, suppressed platelet adhesion and activation, low inflammation potential, and good red blood cell compatibility. Furthermore, the dual-layered membranes exhibited robust antibacterial ability after in situ loading of Ag-nanoparticles with excellent bactericidal capability to both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Due to the integration of the porous membrane structure, good mechanical strength, excellent hemocompatibility, as well as robust bactericidal capability, the GO and sulfonated polyanion co-doped dual-layered membranes may open up a new protocol to greatly demonstrate the potential application of polymeric membranes for clinical hemodialysis and many other biomedical therapies.


Assuntos
Eritrócitos/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Metilgalactosídeos/química , Metilgalactosídeos/farmacologia , Óxidos/química , Staphylococcus aureus/efeitos dos fármacos , Ácidos Sulfônicos/química , Antibacterianos/química , Antibacterianos/farmacologia , Anticoagulantes/farmacologia , Grafite/química , Hidrogel de Polietilenoglicol-Dimetacrilato , Óxidos/farmacologia , Polímeros/química , Ácidos Sulfônicos/farmacologia
18.
Carbohydr Polym ; 150: 201-8, 2016 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-27312630

RESUMO

A recyclable and regenerable magnetic polysaccharide absorbent for methylene blue (MB) removal was prepared by coating magnetic polyethyleneimine nanoparticles (PEI@MNPs) with sulfonated chitosan (SCS) and further cross-linked with glutaraldehyde. The driving force for coating is the electrostactic interaction between positively charged PEI and negatively charged SCS. Infrared spectra, zeta potential, thermal gravimetric analysis and X-ray diffraction demonstrated the successful synthesis of magnetic polysaccharide absorbent. The self-assembly of polysaccharide with magnetic nanopartices did not alter the saturation magnetization value of the absorbent confirmed by vibrating sample magnetometer. The nanoparticles showed fast removal (about 30min reached equilibrium) of MB. In particular, the removal ability of MB after desorption did not reduce, demonstrating an excellent regeneration ability. Our study provides new insights into utilizing polysaccharides for environmental remediation and creating advanced magnetic materials for various promising applications.


Assuntos
Absorção Fisico-Química , Quitosana/química , Corantes/química , Imãs/química , Glutaral/química , Nanopartículas/química , Polietilenoimina/química , Ácidos Sulfônicos/química
19.
Acta Biomater ; 40: 162-171, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27039977

RESUMO

The chemical compositions are very important for designing blood-contacting membranes with good antifouling property and blood compatibility. In this study, we propose a method combining ATRP and click chemistry to introduce zwitterionic polymer of poly(sulfobetaine methacrylate) (PSBMA), negatively charged polymers of poly(sodium methacrylate) (PNaMAA) and/or poly(sodium p-styrene sulfonate) (PNaSS), to improve the antifouling property and blood compatibility of polysulfone (PSf) membranes. Attenuated total reflectance-Fourier transform infrared spectra, X-ray photoelectron spectroscopy and water contact angle results confirmed the successful grafting of the functional polymers. The antifouling property and blood compatibility of the modified membranes were systematically investigated. The zwitterionic polymer (PSBMA) grafted membranes showed good resistance to protein adsorption and bacterial adhesion; the negatively charged polymer (PNaSS or PNaMAA) grafted membranes showed improved blood compatibility, especially the anticoagulant property. Moreover, the PSBMA/PNaMAA modified membrane showed both antifouling property and anticoagulant property, and exhibited a synergistic effect in inhibiting blood coagulation. The functionalization of membrane surfaces by a combination of ATRP and click chemistry is demonstrated as an effective route to improve the antifouling property and blood compatibility of membranes in blood-contact.


Assuntos
Teste de Materiais , Membranas Artificiais , Polímeros/química , Ácidos Polimetacrílicos/química , Poliestirenos/química , Sulfonas/química , Animais , Betaína/análogos & derivados , Betaína/química , Bovinos , Química Click , Escherichia coli/metabolismo , Humanos , Polímeros/síntese química , Ácidos Polimetacrílicos/síntese química , Poliestirenos/síntese química , Soroalbumina Bovina/química , Staphylococcus aureus/metabolismo , Sulfonas/síntese química
20.
J Bone Oncol ; 5(1): 22-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26998423

RESUMO

PURPOSE: Drug resistance has been recognized to be a major obstacle to the chemotherapy for osteosarcoma. And the potential importance of hypoxia as a target to reverse drug resistance in osteosarcoma has been indicated, though the mechanism underlining such role is not clarified. The present study aims to investigate the role of hypoxia in the drug resistance in osteosarcoma cells via activating AMP-activated protein kinase (AMPK) signaling. EXPERIMENTAL DESIGN: We investigated the promotion of the resistance to doxorubicin of osteosarcoma MG-63 and U2-os cells in vitro, and then determined the role of hypoxia-inducible factor-1 (HIF-1)α and HIF-1ß, the activation and regulatory role of AMPK in the osteosarcoma U2-os cells which were treated with doxorubicin under hypoxia. RESULTS: It was demonstrated that hypoxia significantly reduced the sensitivity of MG-63 and U2-os cells to doxorubicin, indicating an inhibited viability reduction and a reduced apoptosis promotion. And such reduced sensitivity was not associated with HIF-1α, though it was promoted by hypoxia in U2-os cells. Interestingly, the AMPK signaling was significantly promoted by hypoxia in the doxorubicin-treated U2-os cells, with a marked upregulation of phosphorylated AMPK (Thr 172) and phosphorylated acetyl-CoA carboxylase (ACC) (Ser 79), which were sensitive to the AMPK activator, AICAR and the AMPK inhibitor, Compound C. Moreover, the promoted AMPK activity by AICAR or the downregulated AMPK activity by Compound C significantly reduced or promoted the sensitivity of U2-os cells to doxorubicin. CONCLUSION: The present study confirmed the AMPK signaling activation in the doxorubicin-treated osteosarcoma cells, in response to hypoxia, and the chemical upregulation or downregulation of AMPK signaling reduced or increased the chemo-sensitivity of osteosarcoma U2-os cells in vitro. Our study implies that AMPK inhibition might be a effective strategy to sensitize osteocarcoma cells to chemotherapy.

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