Hemocompatibility of PET (Polyethylene Terephthalate) Films Grafted PEG (Polyethylene Glycol) by Plasma Surface Modification

2005 ◽  
Vol 288-289 ◽  
pp. 339-342
Author(s):  
Chang Jiang Pan ◽  
Jin Wang ◽  
H. Sun ◽  
Nan Huang
Keyword(s):  
Free Energy ◽  
Polyethylene Glycol ◽  
Surface Structure ◽  
Platelet Adhesion ◽  
Blood Compatibility ◽  
Coagulation Factors ◽  
Attenuated Total Reflection ◽  
Plasma Surface ◽  
Pet Films

In this paper, polyethylene glycol (PEG) of various different molecular weights was grafted onto PET films using plasma surface grafting modification. The surface structure of PEG-grafted PET films was analyzed by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS), suggesting that the surface structure and composition of PET films changes due to the presence of PEG. Blood compatibility was characterized by in vitro platelet adhesion experiments and coagulation factors. The tests of platelet adhesion and coagulation factors in vitro suggest that PEG grafted onto polymer surfaces can improve the blood compatibility of PET films remarkably. The modified PET films were pre-coated with albumin and fibrinogen respectively; platelet adhesion tests in vitro then indicated that samples pre-coated with albumin have better blood compatibility than with fibrinogen, resulting in the conclusion that the albumin can improve blood compatibility. The contact angle of PEG-grafted films was measured by the sessile drop method and the surface free energy and interface free energy were induced. It is indicated that the PEG-grafted PET films have the characteristic of preferentially adsorbing albumin.

Blood Compatibility of Chitosan Immobilized on Poly(Ethylene Terephthalate) Surface Modified by Plasma and Ultraviolet Grafting

2005 ◽  
Vol 288-289 ◽  
pp. 327-330 ◽  
Author(s):  
Jin Wang ◽  
P. Li ◽  
H. Sun ◽  
Ping Yang ◽  
Y.X. Leng ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ethylene Terephthalate ◽  
Blood Compatibility ◽  
Attenuated Total Reflection ◽  
Grafting Modification ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Surface Modified ◽  
Pet Films

We report a study involving chitosan chains immobilized on poly (ethylene terephthalate) (PET) films by plasma and ultraviolet (UV) grafting modification. The surface structure of the modified PET is determined by means of attenuated total reflection Fourier transform infraed spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The results show that the chains of chitosan are successfully grafted on the surface of PET. Platelet adhesion evaluation in vitro is conducted to examine the blood compatibility in vitro. Scanning electron microscopy (SEM) and optical microscopy reveal that the amounts of adhered, aggregated and morphologically changed platelets are reduced on the chitosan-immobilized PET films. The number of platelet adhered on the modified film is reduced by almost 48% compared to the amount of platelets on the untreated film. Our result thus shows that chitosan immobilized on the PET surface improves blood compatibility.

Surface Characterization and In Vitro Blood Compatibility of Poly(Ethylene Terephthalate) Immobilized with Hirudin

2005 ◽  
Vol 288-289 ◽  
pp. 421-424
Author(s):  
F. Li ◽  
Jin Wang ◽  
H. Sun ◽  
Nan Huang
Keyword(s):  
Free Energy ◽  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Ethylene Terephthalate ◽  
Blood Compatibility ◽  
Argon Plasma ◽  
Angle Measurement ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Poly(ethylene terephthalate) films were exposed under argon plasma glow discharge and induced polymerization of acrylic acid (AA) in order to introduce carboxylic acid group onto PET (PET-AA) assisting by ultroviolet radiation. Hirudin-immobilized PETs were prepared by the grafting of PET-AA, followed by chemical reaction with hirudin. The surface structure of the treated PET is determined by X-ray photoelectron spectroscopy (XPS). The wettability and surface free energy, interface free energy of the films is investigated by contact angle measurement. Platelet adhesion evaluatiion is conducted to examine the blood compatibility in vitro. Scanning electron microscopy (SEM) and optical microscopy reveal that the amounts of adhered, aggregated and morphologically changed platelets are reduced on hirudin-immobilized PET films.

Platelet Phagocytosis As A Model For Platelet Adhesion

1981 ◽  
Author(s):  
D R Absolom ◽  
W Zingg ◽  
A W Neumann ◽  
C J van Oss
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Thermodynamic Model ◽  
Platelet Adhesion ◽  
Helmholtz Free Energy ◽  
Hydrophilic Polymers ◽  
Polymer Substrates ◽  
Physical Conditions ◽  
Insight Into

It has been suggested that platelet phagocytosis might be a useful model to provide insight into platelet adhesion to polymer substrates commonly employed in biocompatibility studies. To test this supposition the present study of platelet engulfment of four strains of bacteria (opsonized as well as non-opsonized) under well defined in vitro physical conditions was undertaken. In physiologic conditions, platelet adhesion is maximum on the more hydrophilic polymers and minimum on the more hydrophobic surfaces; bacterial engulfment under the same conditions follows an identical pattern in that the more hydrophilic bacteria are more readily engulfed. The experimental data further suggest that, unlike phagocytosis by neutrophils platelet interaction with bacteria is non-specific in that it does not appear to be antibody receptor modulated. Opsonization of the bacteria does however play an important role in that it serves to increase the hydrophobicity of the bacteria thereby influencing the degree of bacterial engulfment. A striking correlation between the extent of bacterial engulfment and the Helmholtz Free Energy of Engulfment exists. Platelet adhesion to polymer substrates and platelet engulfment of bacteria appear to follow the same thermodynamic model.

In Vitro Blood Compatibility of Alumina Coatings Prepared by Micro-Arc Oxidation on Biomedical NiTi Alloy

2012 ◽  
Vol 184-185 ◽  
pp. 1021-1024 ◽  
Author(s):  
Ji Lin Xu ◽  
Fu Liu ◽  
Jun Ming Luo ◽  
Zhen Chen Zhong
Keyword(s):  
Platelet Adhesion ◽  
Blood Compatibility ◽  
Niti Alloy ◽  
Alumina Coatings ◽  
Oxidation Treatment ◽  
Micro Arc Oxidation ◽  
Surface Morphologies ◽  
Compatibility Of Materials ◽  
Better Than

In this paper, the in vitro blood compatibility of micro-arc oxidation (MAO) alumina coatings prepared in different times on biomedical NiTi alloy was studied using hemolysis ratio, dynamic blood clotting and platelet adhesion. The results show that the blood compatibility of the coated NiTi alloy is much better than that of uncoated NiTi alloy and reduces with increasing the micro-arc oxidation treatment times. Therefore, it can be concluded that the blood compatibility of materials is mainly dominated by the surface species contacted with blood within some ranges of surface roughness, not the surface morphologies, and the MAO alumina coatings can effectively improve the blood compatibility of NiTi alloy

Interaction of Platelets with Model Surfaces III: Platelet Reaction with Synthetic Polymers

1975 ◽  
Author(s):  
J. N. Lindon ◽  
D. Brier ◽  
E. W. Merrill ◽  
E. W. Salzman
Keyword(s):  
Whole Blood ◽  
Platelet Adhesion ◽  
Pyrolytic Carbon ◽  
Coagulation Factors ◽  
Surface Reactivity ◽  
Material Surface ◽  
Release Reaction ◽  
Variable Surface

Blood/material surface interactions have been studied by passing citrated whole blood over beads in a column and examining the resultant activation of platelets and coagulation factors. Examination of many polymer and some crystalline surfaces indicates that platelet adhesion occurs with all surfaces except after pretreatment with albumin in some instances. Induction of the platelet release reaction and platelet adhesion vary from one surface to another and are not well correlated. The release reaction in response to some but not all surfaces can be blocked by pretreatment of blood with aspirin in vivo and indomethacin in vitro. PRP exhibits less activation than whole blood, but varying the hematocrit of whole blood from 23 to 53% does not change surface reactivity.Of the materials studied, polyethylacrylate (PEA) and polymethylacrylate (PMA) appear least reactive. Certain materials, e.g. polystyrene and polyvinylacetate, exhibit variable surface reactivity with different blood samples, while others, e.g. pyrolytic carbon and PMA, produce a uniform response. A general trend appears to be less surface reactivity with decreasing glass transition temperature. Chemical modification of polymers and production of copolymers has been undertaken to define the nature of reactive sites. For example, acrylonitrile and aminomethylacrylate copolymers of PMA exhibit more reactivity than PMA.Sepharose 4B (4% agarose gel beads) appears essentially non-reactive. However, Sepharose with covalently bound heparin promotes extensive platelet adhesion. Pretreatment of this surface with increasing amounts of plasma, but not albumin, produces decreasing surface reactivity.

Surface Characterization and Antibacterial Evaluation of Poly(Ethylene Terephthalate) Modified by Chitosan-Immobilization

2005 ◽  
Vol 288-289 ◽  
pp. 331-334 ◽  
Author(s):  
Peng Li ◽  
Jin Wang ◽  
W.C. Lu ◽  
H. Sun ◽  
Nan Huang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Bacterial Adhesion ◽  
Surface Characterization ◽  
Ethylene Terephthalate ◽  
Attenuated Total Reflection ◽  
Poly Ethylene Terephthalate ◽  
Modified Surface ◽  
Poly Ethylene ◽  
Pet Films

Biomedical PET films were modified by the approach of chitosan-surface-grafting. Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) revealed that chitosan molecules were successfully grafted on the PET surface. The bacterial adhesion on the modified surface was evaluated by bacteria plate counting in vitro and scanning electron microscopy (SEM). The results testified that chitosan did make the surface of PET become more antibacterial. The free energy of adhesion (∆Fadh) between the bacteria and the chitosan-immobilized surface of PET was calculated. The value of the ∆Fadh was positive, which suggests that the process of bacterial adhesion on the modified PET surface was not thermodynamically favorable, namely, not spontaneous.

Plasma graft polymerization of Acrylic Acid and immobilization of Heparin to improve blood compatibility of Polyethylene terephthalate (PET).

2012 ◽  
Vol 1469 ◽  
Author(s):  
Samin Eftekhari ◽  
Hamid Mirzadeh
Keyword(s):  
Acrylic Acid ◽  
Polyethylene Terephthalate ◽  
Active Sites ◽  
Blood Compatibility ◽  
Polymeric Materials ◽  
Attenuated Total Reflection ◽  
Water Contact ◽  
Modified Surfaces ◽  
Novel Method

ABSTRACTPolymeric materials have been attracted the attention of researchers in various R&D applications. In this research, attempts were made to evaluate the changes in blood compatibility of polyethylene terephthalate (PET) by grafting acrylic acid (AAc) and immobilizing heparin by employing two-step plasma treatment. The PET surface was modified by using a novel method named “two-step plasma treatments” (TSPT). While first plasma is creating active sites for grafting, the second plasma polymerizing pre-adsorbed reactive monomer onto the surface of films. Finally, heparin immobilization was performed in the presence of 1-ethyl-3-(dimethylaminopropyl) carbodiimide. All films were characterized by attenuated total reflection Fourier transformed infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM). The surface hydrophilicity of films was studied by water contact angle test and blood compatibility evaluated by Lactate dehydrogenase method (LDH Test). In vitro studies based on LDH results demonstrared that platelet adhesion onto the modified surfaces with heparin was drastically reduced in comparison with unmodified PET.

New Method for Evaluating Material Blood Compatibility Using Microchannel Array

2005 ◽  
Vol 288-289 ◽  
pp. 495-498
Author(s):  
K. Kurotobi ◽  
Akiko Yamamoto ◽  
A. Kikuta ◽  
Takao Hanawa
Keyword(s):  
Whole Blood ◽  
Platelet Adhesion ◽  
Blood Compatibility ◽  
Flow Behavior ◽  
Optical Microscope ◽  
Microchannel Array ◽  
Video Recorder ◽  
Metal Chips ◽  
Pass Through

Microchannel array chips modified by metal deposition or polymer coating were contacted with blood. Titanium (Ti), chromium (Cr) and gold (Au) films were deposited onto the microchannel array chips. Albumin (Alb) and MPC polymer (MPC) were coated onto other chips. Non-treated Si chips were used as a control. Whole blood was collected with 1000 units/ml heparin solution from young healthy volunteers. The passing time of a 100 µl portion of human whole blood through these channels was measured under a pressure difference of 20 cm H2O. Simultaneously, the flow behavior of blood cells in channel was observed by an optical microscope and recorded by a video recorder. Platelet adhesion was observed on Si, Ti, Cr, and especially on Au. The blood pass-through time (BPT) increased in order of Ti, Si, Cr and Au. On the Alb- and MPC-coated chips, platelets were seldom observed and the BPTs were short in comparison with the metal chips. From these consequences, platelet adhesion depended on the materials. The BPT correlated well to the number of adherent platelets on the materials. Therefore, the blood coagulation reaction originated in platelet activation could be detected using microchannel array. We concluded that this method could be applied to evaluate initial blood compatibility of materials within several minutes in vitro.

Imaging of Explanted Mechanical Heart Valves

1998 ◽  
Vol 4 (S2) ◽  
pp. 934-935
Author(s):  
S.L. Goodman ◽  
H. Harasaki ◽  
K.E. Wika ◽  
A.M. Brendzel
Keyword(s):  
Surface Properties ◽  
Heart Valves ◽  
Platelet Adhesion ◽  
Low Voltage ◽  
Blood Compatibility ◽  
Pyrolytic Carbon ◽  
Mechanical Heart Valves ◽  
Preparation Methods ◽  
Biomaterial Application

Prosthetic mechanical heart valves (MHVs) made from pyrolytic carbon (PYC) are a highly successful biomaterial application due to their excellent durability and clinically adequate blood compatibility. Their thromboresistance has been attributed to a combination of hemodynamics, material inertness, and surface properties which minimize platelet adhesion and activation. These surface properties include that polished PYC is smooth and that it strongly adsorbs plasma albumin, which is well known to reduce platelet adhesion. However, recent evidence suggests that this explanation is incomplete. Low voltage SEM shows that PYC valve leaflets are actually quite rough at submicron scales and that PYC induces extensive platelet spreading in vitro in the presence of albumin. Surprisingly few studies have examined MHVs explanted from humans or research animals for platelet adhesion and thrombosis using SEM. Moreover, in most studies it appears that even routine sample preparation methods for the preservation of biological samples for SEM,

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