scholarly journals Anticoagulant Polyethylene Terephthalate Surface by Plasma-Mediated Fucoidan Immobilization

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 750 ◽  
Author(s):  
Kadir Ozaltin ◽  
Marian Lehocky ◽  
Petr Humpolicek ◽  
Jana Pelkova ◽  
Antonio Di Martino ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Photoelectron Spectroscopy ◽  
Anticoagulant Activity ◽  
Blood Clot ◽  
Clot Formation ◽  
Thrombin Time ◽  
Air Plasma ◽  
Water Contact ◽  
Polymeric Biomaterials ◽  
Performance Surface

Biomaterial-based blood clot formation is one of the biggest drawbacks of blood-contacting devices. To avoid blood clot formation, their surface must be tailored to increase hemocompatibility. Most synthetic polymeric biomaterials are inert and lack bonding sites for chemical agents to bond or tailor to the surface. In this study, polyethylene terephthalate was subjected to direct current air plasma treatment to enhance its surface energy and to bring oxidative functional binding sites. Marine-sourced anticoagulant sulphated polysaccharide fucoidan from Fucus vesiculosus was then immobilized onto the treated polyethylene terephthalate (PET) surface at different pH values to optimize chemical bonding behavior and therefore anticoagulant performance. Surface properties of samples were monitored using the water contact angle; chemical analyses were performed by FTIR and X-ray photoelectron spectroscopy (XPS) and their anticoagulant activity was tested by means of prothrombin time, activated partial thromboplastin time and thrombin time. On each of the fucoidan-immobilized surfaces, anticoagulation activity was performed by extending the thrombin time threshold and their pH 5 counterpart performed the best result compared to others.

Plasma-exposed TiO2 nanoparticles on polyethylene terephthalate matrix surface and its effects on the durable hydrophobic coating

2021 ◽  
pp. 004051752199090
Author(s):  
Eshraga AA Siddig ◽  
Yu Zhang ◽  
Baojing Yang ◽  
Tianshu Wang ◽  
Jianjun Shi ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Photoelectron Spectroscopy ◽  
Fiber Surface ◽  
Oil Composition ◽  
Water Contact ◽  
X Ray ◽  
Pet Fabric ◽  
Hydrophobic Coating ◽  
Washing Durability ◽  
Methacrylate Copolymer

Commercial dull polyethylene terephthalate (PET) fabric treated by radio frequency (13.56 MHz) plasma and further coated with perfluoroalkyl methacrylate copolymer C6 displays much highly durable hydrophobicity and oleophobicity. The as-prepared fabric exhibited a water contact angle above 170°, a water spray rating of 80 (ISO 3), and oil resistance ratings of B and C separately for different oil composition grades after 10 washing cycles, which were two levels higher than the untreated and C6-coated PET[TiO2] fabric. The organic component PET was more prone to etching than TiO2, which created a waviness structure and exposed prominent TiO2 nanoparticles on the PET fiber surface. The relative atom ratio O and Ti increased through energy-dispersive X-ray spectroscopy spectra and X-ray photoelectron spectroscopy analysis. This result indicates that the exposure of TiO2 and the introduction of reactive polar groups such as O=C-O on the fiber surface contributed to react with C6 and improved the washing durability. In general, such coating technology may provide a simple benign technique for constructing materials with physicochemical properties.

scholarly journals Experimental investigations of a remote atmospheric pressure plasma by electrical diagnostics and related effects on polymer composite surfaces

2021 ◽  
Author(s):  
Lucie Brès ◽  
Nicolas Gherardi ◽  
Nicolas Naudé ◽  
Bertrand Rives
Keyword(s):  
Photoelectron Spectroscopy ◽  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasma ◽  
Nitrogen Plasma ◽  
Fiber Reinforced Polymers ◽  
Experimental Investigations ◽  
Air Plasma ◽  
Post Discharge ◽  
Water Contact ◽  
Electrical Diagnostics

Surface activation of Carbon Fiber Reinforced Polymers (CFRP) using Poly-EtherEtherKetone (PEEK) matrices is required to achieve strong and long-term adherent painting on the composite. Among the different techniques, an industrial atmospheric pressure remote plasma has been used in this work to treat PEEK CFRP surfaces. The characterization of this device by means of electrical diagnostics related to the effect of such post-discharge on the surface modifications is discussed. Firstly, electrical characteristics of the discharge show fairly high currents associated to high voltages which suggest a nonestablished and cold arc. Power consumed by the electrical supply associated to post-discharge length and surface temperatures allowed a better understanding of the industrial device. Secondly, the effects of plasma on surface chemistry and topography are analyzed by water contact angle measurements, X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM). Investigations showed that treated surfaces exhibited better hydrophilicity mainly due to an incorporation of oxygen containing groups (up to 8.4% more) under air plasma whereas an increase of the nanoroughness and specific surface is preponderant under nitrogen plasma. Different hydrophilic capabilities of the surface obtained in air and nitrogen gas plasma highlight a potential optimization of activation performances according to industrial specification.

Anticoagulant Activity of Hirulog™, a Direct Thrombin Inhibitor, in Humans

1993 ◽  
Vol 69 (02) ◽  
pp. 157-163 ◽  
Author(s):  
Irving Fox ◽  
Adrian Dawson ◽  
Peter Loynds ◽  
Jane Eisner ◽  
Kathleen Findlen ◽  
...  
Keyword(s):  
Rational Design ◽  
Therapeutic Potential ◽  
Anticoagulant Activity ◽  
Subcutaneous Administration ◽  
Direct Thrombin Inhibitor ◽  
Controlled Study ◽  
Thrombin Inhibitor ◽  
Thrombin Time ◽  
Thrombotic Disease ◽  
Dose Dependent

SummaryHirulog™ (BG8967) is a direct thrombin inhibitor built by rational design using the protein hirudin as a model (Maraganore et al. [1990]; Biochemistry 29: 7095–101). In order to evaluate the therapeutic potential for hirulog in the management of thrombotic disease, the tolerability and anticoagulant activity of the agent were examined in a study of human volunteers.In a randomized, placebo-controlled study (n = 54), the intravenous infusion of hirulog over 15 min showed a rapid, dose-dependent prolongation of activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). There was a corresponding dose-dependent increase in plasma hirulog levels. The peptide was rapidly cleared with a half-life of 36 min and a total body clearance rate for the peptide of 0.43 1 kg−1 h−1. Similar activity was observed following subcutaneous injection but with sustained pharmacodynamic and pharmacokinetic behavior. There was a significant correlation between pharmacokinetic and pharmacodynamic variables for both intravenous (r = 0.8, p <0.001) and subcutaneous administration (r = 0.7, p = 0.002).To evaluate the possible interactions of aspirin on the tolerability and anticoagulant activity of intravenous hirulog, a cross-over design was employed in eight subjects. Aspirin administration did not modify the peptide’s activity. At the administered dose of 0.6 mg kg−1 h−1 for 2 h, hirulog infusion prolonged APTT from 230 to 260% baseline. The infusion of hirulog in subjects who had received aspirin was not associated with any significant changes in the template bleeding time.The final phase of the study examined the activity and tolerability of hirulog in ten subjects during prolonged intravenous infusions for up to 24 h. The peptide (0.3 mg kg−1 h−1) exhibited sustained anticoagulant activity with no evidence for a cumulative effect. During hirulog infusion, APTT was prolonged from 210 to 250% baseline.In all phases of the study, hirulog administration was generally well-tolerated.Our observations show that hirulog is an active antithrombin agent with excellent tolerability in humans. As a direct thrombin inhibitor, hirulog provides a novel approach for the management of thrombotic disease.

Utilization of air-plasma treated waste polyethylene terephthalate particles as a raw material for particleboard production

2016 ◽  
Vol 90 ◽  
pp. 188-194 ◽  
Author(s):  
Petr Klímek ◽  
Tomáš Morávek ◽  
Jozef Ráhel ◽  
Monika Stupavská ◽  
David Děcký ◽  
...  
Keyword(s):  
Polyethylene Terephthalate ◽  
Raw Material ◽  
Air Plasma ◽  
Waste Polyethylene

The Haemocompatibility of Biomaterials In Vitro: Investigations on the Mechanism of the Whole-blood Clot Formation Test

1992 ◽  
Vol 20 (3) ◽  
pp. 390-395 ◽  
Author(s):  
Thomas Groth ◽  
Katrin Derdau ◽  
Frank Strietzel ◽  
Frank Foerster ◽  
Hartmut Wolf
Keyword(s):  
Whole Blood ◽  
Blood Clotting ◽  
Blood Clot ◽  
Formation Rate ◽  
Clot Formation ◽  
Coagulation Cascade ◽  
Contact Activation ◽  
Human Fibrinogen ◽  
Static Conditions

Twenty years ago Imai & Nose introduced a whole-blood clotting test for the estimation of haemocompatibility of biomaterials in vitro In our paper a modification of this assay is described and the mechanism of clot formation further elucidated. It was found that neither the inhibition of platelet function nor the removal of platelets from blood significantly changed the clot formation rate on glass and polyvinyl chloride in comparison to the rate tor whole blood. Scanning electron microscopy demonstrated that platelets were not involved in clot formation near the blood/biomaterial interface. Thus, it was concluded that the system of contact activation of the coagulation cascade dominates during clot formation under static conditions. The latter conclusion was supported by the fact that preadsorption of human serum albumin or human fibrinogen onto the glass plates used, decreased the clot formation rate in the same manner.

Preparation and properties of polyurethane coatings modified by polysilazane

2019 ◽  
Vol 32 (6) ◽  
pp. 611-619 ◽  
Author(s):  
Xiaoli Liu ◽  
Zhen Ge ◽  
Wenguo Zhang ◽  
Yunjun Luo
Keyword(s):  
Mechanical Property ◽  
Photoelectron Spectroscopy ◽  
Composite Coatings ◽  
Composite Films ◽  
Dip Coating ◽  
Water Contact ◽  
Research Attention ◽  
Elongation At Break ◽  
Coating Method ◽  
Dip Coating Method

Due to their unique physicochemical properties, polysilazanes exhibit excellent performance when combined with some resin matrixes, which had drawn great research attention. In this article, polyurethane (PU) was firstly prepared by polytetrahydrofuran glycol, isophorone diisocyanate, and 1,4-butanediol as main materials. Then, the prepared PU was blended with polysilazane by mixing the two solutions together, which was cured to films via dip-coating method at room temperature. The structure, thermal stability, and surface properties of the composite coatings were investigated by Fourier-transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy. The results demonstrated that after modification with polysilazane, the heat resistance, hydrophobicity, and mechanical property of the PU coatings were improved. When the content of polysilazane was 6 wt%, the mechanical property of the composite films was optimized, with a maximum tensile strength of 25.7 MPa and elongation at break of 797%. Meanwhile, the water contact angle of the composite film was 107° and the water absorption reached a minimum of 2.1%, which showed improved hydrophobicity and water resistance.

scholarly journals P4VP Modified Zwitterionic Polymer for the Preparation of Antifouling Functionalized Surfaces

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 706 ◽  
Author(s):  
Chaoqun Wu ◽  
Yudan Zhou ◽  
Haitao Wang ◽  
Jianhua Hu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Cell Attachment ◽  
Raft Polymerization ◽  
Polymer Brush ◽  
Contact Angles ◽  
Polymerization Process ◽  
Water Contact ◽  
Zwitterionic Polymers ◽  
Ito Glass ◽  
Zwitterionic Polymer

Zwitterionic polymers are suitable for replacing poly(ethylene glycol) (PEG) polymers because of their better antifouling properties, but zwitterionic polymers have poor mechanical properties, strong water absorption, and their homopolymers should not be used directly. To solve these problems, a reversible-addition fragmentation chain transfer (RAFT) polymerization process was used to prepare copolymers comprised of zwitterionic side chains that were attached to an ITO glass substrate using spin-casting. The presence of 4-vinylpyridine (4VP) and zwitterion chains on these polymer-coated ITO surfaces was confirmed using 1H NMR, FTIR, and GPC analyses, with successful surface functionalization confirmed using water contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) studies. Changes in water contact angles and C/O ratios (XPS) analysis demonstrated that the functionalization of these polymers with β-propiolactone resulted in hydrophilic mixed 4VP/zwitterionic polymers. Protein adsorption and cell attachment assays were used to optimize the ratio of the zwitterionic component to maximize the antifouling properties of the polymer brush surface. This work demonstrated that the antifouling surface coatings could be readily prepared using a “P4VP-modified” method, that is, the functionality of P4VP to modify the prepared zwitterionic polymer. We believe these materials are likely to be useful for the preparation of biomaterials for biosensing and diagnostic applications.

Improvement of Interfacial Adhesion in PP/PS Blends Enhanced with Polyethylene-Polyamine Surface Treated Carbon Fiber

2014 ◽  
Vol 1061-1062 ◽  
pp. 170-174
Author(s):  
Jian Li
Keyword(s):  
Contact Angle ◽  
Carbon Fiber ◽  
Photoelectron Spectroscopy ◽  
Interfacial Adhesion ◽  
Morphological Changes ◽  
Water Contact ◽  
Polyethylene Polyamine ◽  
Adhesion Behavior ◽  
Interlaminar Shear ◽  
Treated Carbon

The effects of surface treatment of a carbon fiber (CF) by Polyethylene-polyamine (PEPA) on the interfacial adhesion behavior and morphology of polypropylene/polystyrene (PP/PS) matrix blends filled CF composites were investigated. Effects of surface treated a commercial CF on mechanical properties are studied. Contact angle was measured to examine the changes in wettability of the carbon fiber. The chemical and morphological changes were characterized by using X-ray photoelectron spectroscopy (XPS). PP/PS/CF composites were fabricated with and without PEPA treatment, and their interlaminar fracture toughnesses were compared. The results showed that the interlaminar shear strength (ILSS) of composites has been greatly improved filled PEPA modification CF. The water contact angle of resin sample decreased 50% after addition of PEPA surface treated CF.

Plasma Pre-Treatment of Polyethylene Terephthalate Substrate Influence on the Properties of ZnO Thin Film

2014 ◽  
Vol 895 ◽  
pp. 41-44
Author(s):  
Seiw Yen Tho ◽  
Kamarulazizi Ibrahim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Polyethylene Terephthalate ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Water Contact ◽  
Pre Treatment ◽  
Pet Substrate

In this work, the influences of plasma pre-treatment on polyethylene terephthalate (PET) substrate to the properties of ZnO thin film have been carried out. ZnO thin films were successfully grown on PET substrate by spin coating method. In order to study the effects of plasma pre-treatment, a comparison of treated and untreated condition was employed. Water contact angle measurement had been carried out for PET wettability study prior to ZnO thin film coating. Morphology study of ZnO thin film was performed by scanning probe microscope (SPM). Besides, optical study of the ZnO thin film was done by using UV-vis spectrophotometer. All the measured results show that plasma pre-treatment of PET substrate plays an important role in enhancing the wettability of PET and optical properties of the ZnO thin films. In conclusion, pre-treatment of PET surface is essential to produce higher quality ZnO thin film on this particular substrate in which would pave the way for the integration of future devices.

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