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1.
Langmuir ; 35(5): 1312-1319, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29936847

RESUMO

Surface functionalization of polymeric porous substrates is one of the most important requirements to enhance their applications in the biomedical field. In this study, we achieved photoinduced surface modification using a highly efficient reaction of hydrophilic polymers bearing phosphorylcholine groups. Polymers composed of 2-methacryloyloxyethyl phosphorylcholine (MPC) units and 2-( N-ethylanilino)ethyl methacrylate units were synthesized with attention to the polymer architectures. The surface modification of the porous polyethylene (PE) substrates was carried out by the coating of the MPC polymers with a photochemical radical generator, followed by photoirradiation for a few minutes. Surface analysis by attenuated total reflectance Fourier transform IR spectroscopy and X-ray photoelectron spectroscopy indicated that the MPC polymer layer was generated on the PE surface. Cross-sectional confocal microscopy images showed that the MPC polymers were coated on the polymer surface, even inside the porous structure of the PE substrate. After modification, the porous PE substrates showed a significant increase in hydrophilicity and the water-penetration rate through the pores. Furthermore, the amount of protein adsorbed on the PE substrate was reduced significantly by the surface modification. These functionalities were dependent on the MPC polymer architectures. Thus, we concluded that the photoreactive polymer system developed furnished the porous substrates with antifouling properties.

2.
Langmuir ; 33(8): 1914-1926, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-28147481

RESUMO

Cationic vectors are ideal candidates for gene delivery thanks to their capability to carry large gene inserts and their scalable production. However, their cationic density gives rise to high cytotoxicity. We present the proper designed core-shell polyplexes made of either poly(ethylene imine) (PEI) or poly(2-dimethylamino ethyl methacrylate) (PDMAEMA) as the core and zwitterionic poly(acrylic acid)-block-poly(sulfobetaine methacrylate) (PAA-b-PSBMA) diblock copolymer as the shell. Gel retardation and ethidium bromide displacement assays were used to determine the PEI/DNA or PDMAEMA/DNA complexation. At neutral pH, the copolymer serves as a protective shell of the complex. As PSBMA is a nonfouling block, the shell reduced the cytotoxicity and enhanced the hemocompatibility (lower hemolysis activity, longer plasma clotting time) of the gene carriers. PAA segments in the copolymer impart pH sensitivity by allowing deshielding of the core in acidic solution. Therefore, the transfection efficiency of polyplexes at pH 6.5 was better than at pH 7.0, from ß-galactosidase assay, and for all PAA-b-PSBMA tested. These results were supported by more favorable physicochemical properties in acidic solution (zeta potential, particle size, and interactions between the polymer and DNA). Thus, the results of this study offer a potential route to the development of efficient and nontoxic pH-sensitive gene carriers.


Assuntos
Polímeros/química , DNA , Técnicas de Transferência de Genes , Concentração de Íons de Hidrogênio , Iminas/química , Metacrilatos/química , Nylons/química , Polietilenos/química
3.
Langmuir ; 33(2): 611-621, 2017 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-27802598

RESUMO

To overcome the thrombogenic reactions of hydrocarbon-based biomaterials in clinical blood treatment, we introduce a model study of surface zwitterionization of a polypropylene (PP) substrate using a set of well-defined copolymers for controlling the adhesion of blood cells in vitro. Random and block copolymers containing zwitterionic units of 2-methacryloyloxyethyl phosphorylcholine (MPC), [3-(methacryloylamino)propyl]dimethyl(3-sulfopropyl)ammonium hydroxide inner salt (SBAA), or nonionic units of 2-hydroxyethyl methacrylate (HEMA) with a controlled hydrophobic segment of 70% n-butyl methacrylate (BMA) units in these polymers were synthesized through reversible addition-fragmentation chain transfer polymerization. A systematic study of how zwitterionic and nonionic copolymer architectures associated with controlled chain orientation via hydration processes affect blood compatibility is reported. The surface wettability of PP substrates coated with the block copolymer with poly(MPC) (PMPC) segments was higher than that of the random copolymer poly(MPC-random-BMA). However, only the random copolymers with SBAA units demonstrate a higher surface wettability. The PP substrate coated with nonionic copolymers containing HEMA units showed relatively lower hydration capability associated with higher protein adsorption, platelet adhesion, and leukocyte attachment than those with zwitterionic copolymers. The random copolymer poly(SBAA-random-BMA) coated on the PP substrates exhibited resistance to cell adhesion in human whole blood at a level comparable to that of MPC copolymers. An ideal zwitterionic PP substrate could be obtained by coating it with a block copolymer composed of PMPC and poly(BMA) (PBMA) segments, PMPC-block-PBMA. The water contact angle decreased dramatically from approximately 100° on the original PP substrate to 11° within 30 s. The number of blood cells attached on PMPC-block-PBMA decreased significantly to less than 2.5% of that on original PP. These results prove that the rational design of zwitterionic polymers incorporated with a hydrophobic anchoring portion provides a promising approach to reduce blood cell adhesion and protein adsorption of hydrocarbon-based biomaterials applied in direct contact with human whole blood.


Assuntos
Polipropilenos/química , Materiais Biocompatíveis/química , Adesão Celular/efeitos dos fármacos , Humanos , Teste de Materiais , Metacrilatos/química , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Polímeros/química , Polipropilenos/farmacologia
4.
ACS Appl Mater Interfaces ; 6(12): 9858-70, 2014 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-24881869

RESUMO

Herein, a pseudozwitterionic structure bearing moieties with mixed positive and negative charges is introduced to develop a potential biomaterial for wound dressing applications. New mixed-charge matrices were prepared by copolymerization of the negatively charged 3-sulfopropyl methacrylate (SA) and positively charged [2-(methacryloyloxy)ethyl] trimethylammonium (TMA) onto expanded polytetrafluoroethylene (ePTFE) membranes. The charge balance was effectively regulated through the control of the initial SA/TMA ratio. The focus was then laid on the assessment of a variety of essential properties of efficient wound dressings including, hydration property, resistance to fibrinogen adsorption, hemocompatibility, as well as resistance to fibroblast attachment and bacteria colonization. It was found that the pseudozwitterionic membranes, compared to those with charge bias in the poly(SA-co-TMA) structure, exhibited the best combination of major properties. Therefore, they were further tested for wound healing. Histological examination of mouse wound treated with the pseudozwitterionic membranes exhibited complete re-epithelialization and total formation of new connective tissues after 14 days, even leading to faster healing than using commercial dressing. Results presented in this work suggest that the mixed-charge copolymers with a perfect balance of positive and negative moieties represent the newest generation of biomaterials for wound dressings.


Assuntos
Materiais Biocompatíveis/química , Polímeros/química , Cicatrização , Adsorção , Animais , Materiais Biocompatíveis/uso terapêutico , Humanos , Camundongos , Polímeros/uso terapêutico
5.
ACS Appl Mater Interfaces ; 5(14): 6732-42, 2013 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-23795955

RESUMO

Development of bioinert membranes to prevent blood clotting, tissue adhesion, and bacterial attachment is important for the wound healing process. In this work, two wound-contacting membranes of expanded poly(tetrafluoroethylene) (ePTFE) grafted with zwitterionic poly(sulfobetaine methacrylate) (PSBMA) and hydrophilic poly(ethylene glycol) methacrylate (PEGMA) via atmospheric plasma-induced surface copolymerization were studied. The surface grafting chemical structure, hydrophilicity, and hydration capability of the membranes were determined to illustrate the correlations between bioadhesive properties and wound recovery of PEGylated and zwitterionic ePTFE membranes. Bioadhesive properties of the membranes were evaluated by the plasma protein adsorption, platelet activation, blood cell hemolysis, tissue cell adhesion, and bacterial attachment. It was found that the zwitterionic PSBMA-grafted ePTFE membrane presented high hydration capability and exhibited the best nonbioadhesive character in contact with protein solution, human blood, tissue cells, and bacterial medium. This work shows that zwitterionic membrane dressing provides a moist environment, essential for "deep" skin wound healing observed from the animal rat model in vivo and permits a complete recovery after 14 days, with histology of repaired skin similar to that of normal skin tissue. This work suggests that the bioinert nature of grafted PSBMA polymers obtained by controlling grafting structures gives them great potential in the molecular design of antibioadhesive membranes for use in skin tissue regeneration.


Assuntos
Materiais Biocompatíveis/química , Membranas Artificiais , Polímeros/química , Adsorção , Animais , Aderência Bacteriana/efeitos dos fármacos , Betaína/análogos & derivados , Betaína/química , Materiais Biocompatíveis/farmacologia , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Linhagem Celular Tumoral , Modelos Animais de Doenças , Escherichia coli/fisiologia , Fluorcarbonetos/química , Humanos , Metacrilatos/química , Polietilenoglicóis/química , Polimerização , Ratos , Ratos Sprague-Dawley , Pele/lesões , Staphylococcus epidermidis/fisiologia , Propriedades de Superfície , Cicatrização/efeitos dos fármacos
6.
Langmuir ; 28(51): 17733-42, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23181727

RESUMO

In this work, the hemocompatibility of zwitterionic polypropylene (PP) fibrous membranes with varying grafting coverage of poly(sulfobetaine methacrylate) (PSBMA) via plasma-induced surface polymerization was studied. Charge neutrality of PSBMA-grafted layers on PP membrane surfaces was controlled by the low-pressure and atmospheric plasma treatment in this study. The effects of grafting composition, surface hydrophilicity, and hydration capability on blood compatibility of the membranes were determined. Protein adsorption onto the different PSBMA-grafted PP membranes from human fibrinogen solutions was measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. Blood platelet adhesion and plasma clotting time measurements from a recalcified platelet-rich plasma solution were used to determine if platelet activation depends on the charge bias of the grafted PSBMA layer. The charge bias of PSBMA layer deviated from the electrical balance of positively and negatively charged moieties can be well-controlled via atmospheric plasma-induced interfacial zwitterionization and was further tested with human whole blood. The optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and keeps its original blood-inert property of antifouling, anticoagulant, and antithrmbogenic activities when it comes into contact with human blood. This work suggests that the hemocompatible nature of grafted PSBMA polymers by controlling grafting quality via atmospheric plasma treatment gives a great potential in the surface zwitterionization of hydrophobic membranes for use in human whole blood.


Assuntos
Betaína/análogos & derivados , Materiais Biocompatíveis/química , Membranas Artificiais , Plasma/química , Polipropilenos/química , Adsorção , Anticoagulantes/química , Anticoagulantes/farmacologia , Betaína/química , Materiais Biocompatíveis/farmacologia , Proteínas Sanguíneas/química , Humanos , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Adesividade Plaquetária/efeitos dos fármacos , Propriedades de Superfície
7.
Bioresour Technol ; 102(2): 1028-34, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21035328

RESUMO

This study applied a pilot-scale trickle-bed air biofilter (TBAB) system for treating waste gas emitted from the breather vent of a vertical fixed roof storage tank containing p-xylene (p-X) liquid. The volatile organic compound (VOC) concentration of the waste gas was related to ambient temperature as well as solar radiation, peaking at above 6300 ppmv of p-X and 25000 ppmv of total hydrocarbons during the hours of 8 AM to 3 PM. When the activated carbon adsorber was employed as a VOC buffer, the peak waste gas VOC concentration was significantly reduced resulting in a stably and efficiently performing TBAB system. The pressure drop appeared to be low, reflecting that the TBAB system could be employed in the prolonged operation with a low running penalty. These advantages suggest that the TBAB system is a cost-effective treatment technology for VOC emission from a fixed roof storage tank.


Assuntos
Ar , Filtração/instrumentação , Gases/isolamento & purificação , Eliminação de Resíduos/instrumentação , Eliminação de Resíduos/métodos , Resíduos/análise , Xilenos/análise , Biodegradação Ambiental , Umidade , Resíduos Industriais/análise , Projetos Piloto , Pressão , Estações do Ano , Temperatura , Fatores de Tempo , Compostos Orgânicos Voláteis/análise , Água
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