Plasma Protein Adsorption and Platelet Adhesion on Poly[Bis(Trifluoroethoxy)Phosphazene]

1997 ◽  
Vol 489 ◽  
Author(s):  
Alexander Welle ◽  
Michael Grunze ◽  
Dsidra Tur
Keyword(s):  
Platelet Adhesion ◽  
Blood Compatibility ◽  
Bulk Material ◽  
Coagulation Cascade ◽  
Medical Implants ◽  
Protein Film ◽  
High Molar Mass ◽  
Adsorbed Protein ◽  
Adsorbed Proteins ◽  
Plasma Protein Adsorption

AbstractPoly[bis(trifluoroethoxy)phosphazene] (PTFEP) with a high purity and high molar mass is a biocompatible material [1] used as bulk material in medical implants. We developed a process to coat surfaces with PTFEP films and performed ELISA experiments designed to understand their blood compatibility. We observed that PTFEP adsorbs preferentially albumin from plasma, and only small amounts of coagulation or inflammation stimulating proteins. In general, there is a good correlation between increasing content of albumin in the adsorbed protein film and reduced platelet adhesion. Another important prerequisite of blood compatibility is the stabilization of the native state of adsorbed proteins, since denaturated proteins stimulate platelet adhesion. The elutability of adsorbed proteins by sodiumdodecylsulfate solution was used to quantify the amount of irreversible attached and presumably denaturated proteins. PTFEP showed a low amount of irreversibly adsorbed proteins of the coagulation cascade. Circular dichroism measurements of adsorbed fibrinogen and albumin showed only weak distortions of the secondary structure of these proteins on the surface of PTFEP.We conclude that PTFEP has a unique blood compatibility because of the favorable composition and the stabilization of the protein layer against denaturation.

Regulation der primären Hämostase durch von-Willebrand-Faktor und ADAMTS13

2011 ◽  
Vol 31 (04) ◽  
pp. 275-280 ◽  
Author(s):  
U. Budde ◽  
R. Schneppenheim
Keyword(s):  
Platelet Adhesion ◽  
Coagulation Factor ◽  
Von Willebrand Disease ◽  
Coagulation Cascade ◽  
Platelet Glycoprotein ◽  
Platelet Adhesion And Aggregation ◽  
Hydrodynamic Shear ◽  
Specific Protease ◽  
Multiple Domains ◽  
Von Willebrand

SummaryVon Willebrand factor (VWF) is an adhesive, multi-functional huge multimerized protein with multiple domains harboring binding sites for collagen, platelet glycoprotein receptors and coagulation factor VIII (FVIII). The functional domains enable VWF to bind to the injured vessel wall, to recruit platelets to the site of injury by adhesion and aggregation and to bind and protect FVIII, an important cofactor of the coagulation cascade. VWF function in primary haemostasis is located in particular in the arterial and micro-circulation. This environment is exposed to high shear forces with hydrodynamic shear rates ranging over several orders of magnitude from 10–1 to 105 s-1 and requires particular mechanisms to enable platelet adhesion and aggregation under these variable conditions. The respective VWF function is strictly correlating with its multimer size. Lack or reduction of large VWF multimers is seen in patients with von Willebrand disease (VWD) type 2A which correlates with reduction of both VWF:platelet GPIb-binding and VWF:collagen binding and a bleeding phenotype. To prevent unlimited platelet adhesion and aggregation which is the cause of the microangiopathic disorder thrombotic thrombocytopenic purpura (TTP), VWF function is regulated by its specific protease ADAMTS13. Whereas a particular susceptibility of VWF to ADAMTS13 proteolysis is the cause of a frequent VWD type 2A phenotype, lack or dysfunction of ADAMTS13, either acquired by ADAMTS13 antibodies or by inherited ADAMTS13 deficiency (Upshaw-Schulman Syndrome), causes TTP. Therefore VWD and TTP represent the opposite manifestations of VWF related disorders, tightly linked to each other.

scholarly journals Thrombospondin inhibits adhesion of platelets to glass and protein- covered substrata

Blood ◽  
1988 ◽  
Vol 71 (4) ◽  
pp. 1096-1099 ◽  
Author(s):  
J Lahav
Keyword(s):  
Platelet Adhesion ◽  
Binding Capacity ◽  
Inhibitory Effect ◽  
Adsorbed Protein ◽  
Platelet Binding ◽  
Platelet Spreading ◽  
Glass Surfaces ◽  
Adhesion Of Platelets

Abstract Glass and protein-covered surfaces when treated with the platelet- secreted glycoprotein thrombospondin lose their capacity to bind unstimulated platelets. In comparison to the number that bind to fibronectin-covered glass surfaces, less than 3% bind to thrombospondin- covered glass surfaces. When the fibronectin-covered surface is incubated with thrombospondin, it loses 87% of its binding capacity for platelets. The inhibitory effect of thrombospondin on platelet binding increases with increasing amounts of the adsorbed protein and reaches maximal values at 65% saturation of the adsorption of thrombospondin to the surface. Platelet spreading on the surface is also completely inhibited by thrombospondin. These data suggest that thrombospondin is nonthrombogenic and can modulate platelet adhesion to the subendothelium.

Blood Compatibility of Metal Oxide Layers on Stainless-steel

2002 ◽  
Vol 734 ◽  
Author(s):  
Kanji Tsuru ◽  
Shinji Takemoto ◽  
Tatsuhiro Yamamoto ◽  
Satoshi Hayakawa ◽  
Akiyoshi Osaka ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Oxide Layer ◽  
Titanium Oxide ◽  
Platelet Adhesion ◽  
Blood Compatibility ◽  
Platelet Rich Plasma ◽  
Sol Gel ◽  
Dip Coating ◽  
Titanium Oxide Layer ◽  
Oxide Layers

ABSTRACTWe examined blood compatibility of titanium oxide layer on stainless-steel (SUS316L). The oxide layers with varied thickness were yielded on SUS316L plates by dip-coating of sol-gel solution starting from tetraethyltitanate. The blood compatibility was evaluated in term of platelet adhesion using platelet rich plasma. With increase in the thickness of the oxide layer, the number of adherent platelets decreased rapidly, reached minimum around 150nm. This indicated that the thickness of titanium oxide layer affected platelet adhesion.

scholarly journals Integrating blood cell mechanics, platelet adhesive dynamics and coagulation cascade for modelling thrombus formation in normal and diabetic blood

2021 ◽  
Vol 18 (175) ◽  
pp. 20200834
Author(s):  
Alireza Yazdani ◽  
Yixiang Deng ◽  
He Li ◽  
Elahe Javadi ◽  
Zhen Li ◽  
...  
Keyword(s):  
Blood Cell ◽  
Cell Mechanics ◽  
Platelet Adhesion ◽  
Thrombus Formation ◽  
Physiological Mechanism ◽  
Coagulation Factors ◽  
Coagulation Cascade ◽  
Vascular Events ◽  
Excessive Bleeding ◽  
Pathological Conditions

Normal haemostasis is an important physiological mechanism that prevents excessive bleeding during trauma, whereas the pathological thrombosis especially in diabetics leads to increased incidence of heart attacks and strokes as well as peripheral vascular events. In this work, we propose a new multiscale framework that integrates seamlessly four key components of blood clotting, namely transport of coagulation factors, coagulation kinetics, blood cell mechanics and platelet adhesive dynamics, to model the development of thrombi under physiological and pathological conditions. We implement this framework to simulate platelet adhesion due to the exposure of tissue factor in a three-dimensional microchannel. Our results show that our model can simulate thrombin-mediated platelet activation in the flowing blood, resulting in platelet adhesion to the injury site of the channel wall. Furthermore, we simulate platelet adhesion in diabetic blood, and our results show that both the pathological alterations in the biomechanics of blood cells and changes in the amount of coagulation factors contribute to the excessive platelet adhesion and aggregation in diabetic blood. Taken together, this new framework can be used to probe synergistic mechanisms of thrombus formation under physiological and pathological conditions, and open new directions in modelling complex biological problems that involve several multiscale processes.

scholarly journals The Study of Physicochemical Properties and Blood Compatibility of Sodium Alginate-Based Materials via Tannic Acid Addition

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4905
Author(s):  
Beata Kaczmarek-Szczepańska ◽  
Adrianna Sosik ◽  
Anna Małkowska ◽  
Lidia Zasada ◽  
Marta Michalska-Sionkowska
Keyword(s):  
Sodium Alginate ◽  
Tannic Acid ◽  
Platelet Adhesion ◽  
Biomedical Application ◽  
Blood Compatibility ◽  
Material Surface ◽  
Scanning Calorimetry ◽  
Atomic Force ◽  
Rate Study ◽  
Scanning Electron

In this study, sodium alginate-based thin films were modified by the addition of tannic acid. Materials were obtained by solvent evaporation. They were characterized by the observation of its morphology and its surface by scanning electron microscope and atomic force microscope. The thermal properties were studied by differential scanning calorimetry. The concentration of tannic acid released from the material was determined by the Folin–Ciocalteu method. The material safety for biomedical application was determined by the hemolysis rate study in contact with sheep blood as well as platelet adhesion to the material surface. Based on the obtained results, we assume that proposed films based on sodium alginate/tannic acid are safe and may potentially find application in medicine.

On the Mechanism of Coagulation Inhibition on Surfaces with End Point Immobilized Heparin

1993 ◽  
Vol 70 (02) ◽  
pp. 289-293 ◽  
Author(s):  
G Elgue ◽  
M Blombäck ◽  
P Olsson ◽  
J Riesenfeld
Keyword(s):  
Enzyme Inhibitor ◽  
Blood Compatibility ◽  
Present Report ◽  
Factor Xa ◽  
Test Tube ◽  
Coagulation Cascade ◽  
High Affinity ◽  
End Point ◽  
Artificial Materials ◽  
Coagulation Inhibition

SummaryA well established technique to improve blood compatibility of artificial materials for use in the circulation is to coat the surface with heparin. The present report describes the antithrombin mediated inhibition of thrombin and factor Xa by surfaces modified with end point immobilized heparin. The reaction was followed by conventional chromogenic substrate based enzyme assays as well as by immunological measurement of the enzyme inhibitor (thrombin-antithrombin) complex formation. Both enzymes were rapidly inactivated by heparin surfaces after selective presaturation with antithrombin on the immobilized high affinity heparin molecules. The thrombin inhibitory capacity was enhanced when both high and low affinity heparin were preadsorbed with inhibitor. The main part of the thrombin-antithrombin complex formed remained bound to the surface, however, without functionally blocking the activity of the high affinity sequence of the immobilized heparin.Aliquots of recalcified plasma were slowly rotated in loops of heparinized tubing to investigate whether the main thromboresistant function of the surface was exerted at the level of thrombin or by inactivation of preceding enzymes. After 1 h no visible clotting occurred and only trace amounts of thrombin (0.07 IU/ml), measured as thrombin-antithrombin complexes, had been formed. In non-heparinized loops and in the test tube plasma clotted after 20 min. The thrombin generation when clotting occurred was in the order of 10 IU/ml. It is concluded that the immobilized heparin mediates inhibition of the coagulation cascade prior to prothrombin activation.

Antithrombogenic properties of Tulbaghia violacea–loaded polycaprolactone nanofibers

2020 ◽  
Vol 35 (2) ◽  
pp. 102-116
Author(s):  
Lerato N Madike ◽  
Michael Pillay ◽  
Ketul C Popat
Keyword(s):  
Medical Devices ◽  
Plant Extracts ◽  
Platelet Adhesion ◽  
Blood Compatibility ◽  
Fibre Diameter ◽  
Electrospinning Technique ◽  
Implantable Medical Devices ◽  
Biomaterial Surfaces ◽  
Rate Of Failure ◽  
Novel Scaffold

A broad range of polymers have been utilized for the development of blood-contacting implantable medical devices; however, their rate of failure has raised the need for developing more hemocompatible biomaterial surfaces. In this study, a novel scaffold based on polycaprolactone incorporated with 10% and 15% (w/w) Tulbaghia violacea plant extracts were fabricated using electrospinning technique. The fabricated scaffolds were then treated with T. violacea aqueous plant extracts (100 and 1000 µg/mL) to investigate their use as interfaces for blood-contacting implants. The 10% Tvio scaffold produced the lowest mean fibre diameter (193 ± 30 nm), whereas the 15% Tvio scaffold produces the highest mean fibre diameter (538 ± 236 nm) when compared with the control polycaprolactone (275 ± 61 nm) scaffold. The number of adhered platelets was directly linked to fibre diameter and concentration of plant extract in such a way that the lowest fibre diameter scaffold (10% Tvio) inhibited platelet adhesion, whereas more platelets adhered to the scaffold with the highest fibre diameter (15% Tvio scaffolds). There was also an increase in platelet adhesion as the concentration of T. violacea was increased from 100 to 1000 µg/mL for all designed scaffolds. The improved blood compatibility demonstrated by the 10% Tvio scaffold suggests that the plant possesses antithrombogenic properties, particularly at lower concentrations.

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.

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