The Experts below are selected from a list of 987 Experts worldwide ranked by ideXlab platform
Thomas A. Horbett - One of the best experts on this subject based on the ideXlab platform.
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the role of complement c3 and fibrinogen in monocyte adhesion to peo like plasma deposited Tetraglyme
Journal of Biomedical Materials Research Part A, 2010Co-Authors: Luisa Mayorga Szott, Thomas A. HorbettAbstract:The role of complement C3 in mediating adhesion of monocytes to plasma deposited Tetraglyme surfaces was studied. Although fibrinogen (Fg) is usually considered the main factor in mediating phagocyte attachment, plasma deposited PEO-like tetraethylene glycol dimethyl ether (Tetraglyme) coatings that have ultra-low Fg adsorption (<10 ng cm(-2)) from low concentration solutions and low monocyte adhesion in vitro still show high phagocyte adhesion after short implantations and later become encapsulated when tested in vivo. To test whether higher Fg adsorption under in vivo conditions could explain the higher in vivo reactivity, we again measured the resistance of Tetraglyme films to Fg adsorption. We found a surprising and previously unreported increased amount of adsorbed Fg on Tetraglyme surfaces from higher concentration protein solutions. However, monocyte adhesion to Tetraglyme did not markedly increase despite the increased Fg adsorption. We thus suspected proteins other than Fg must be responsible for the increased in vivo reactivity. We found that on Tetraglyme preadsorbed with C3-depleted serum, monocyte adhesion was greatly reduced as compared to samples adsorbed with normal serum. Addition of exogenous pure C3 to the serum used to preadsorb the surfaces restored monocyte adhesion to Tetraglyme coatings. While Fg clearly plays an important role in mediating monocyte adhesion to Tetraglyme surfaces, the results show an additional role for adsorbed C3 in monocyte adhesion.
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Tetraglyme coatings reduce fibrinogen and von Willebrand factor adsorption and platelet adhesion under both static and flow conditions.
Journal of biomedical materials research. Part A, 2009Co-Authors: Min Zhang, Thomas A. HorbettAbstract:Previous studies have showed that radio-frequency plasma deposited Tetraglyme coatings greatly reduced fibrinogen adsorption (Gamma(Fg)) from highly diluted plasmas (0.1 and 1%) and subsequent platelet adhesion under static conditions. In this study, the protein resistant properties of Tetraglyme were re-examined with high-concentration plasma, and subsequent platelet adhesion was measured under both static and flow conditions. The resistance of Tetraglyme to vWf adsorption (Gamma(vWf)) and the role of vWf in platelet adhesion under flow were also investigated. Gamma(Fg) and Gamma(vWf) were measured with (125)I radiolabeled proteins. Flow studies were done at shear rates of 50 or 500 s(-1) by passing a platelet/red cell suspension through a GlycoTech flow chamber. When adsorbed from a series of increasing plasma concentrations, the adsorption of both proteins to Tetraglyme increased steadily, and did not show a peak at intermediate dilutions, i.e., there was no Vroman effect. When plasma concentration was less than 10%, the Tetraglyme surface was highly nonfouling, exhibiting ultralow Gamma(Fg) (less than 5 ng/cm(2)) and extremely low platelet adhesion under both static and flow conditions. However, when the adsorption was done from 100% plasma, Gamma(Fg) was much higher ( approximately 85 ng/cm(2)), indicating that Tetraglyme surface may not be sufficiently protein-resistant in the physiological environment. To correlate platelet adhesion under flow with Gamma(Fg) and Gamma(vWf), a series of Tetraglyme surfaces varying in ether content and protein adsorption was created by varying deposition power. On these surfaces, platelet adhesion at low shear rate depended only on the amount of Gamma(Fg), but under high shear, both Gamma(Fg) and Gamma(vWf) affected platelet adhesion. In particular, it was found that Gamma(vWf) must be reduced to less than 0.4 ng/cm(2) to achieve ultra low platelet adhesion under high shear.
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plasma deposited Tetraglyme surfaces greatly reduce total blood protein adsorption contact activation platelet adhesion platelet procoagulant activity and in vitro thrombus deposition
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Lan Cao, Buddy D Ratner, David G. Castner, Sivaprasad Sukavaneshvar, Mark L Chang, Chi Ying Lee, Thomas A. HorbettAbstract:The ability of tetraethylene glycol dimethyl ether (Tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Willebrand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagulant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that Tetraglyme surfaces strongly resisted the adsorption of all proteins from human plasma. The clotting time in the presence of Tetraglyme surfaces was lengthened compared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on Tetraglyme-coated materials, compared with uncoated and Biospan-coated glass slides. In the in vitro disturbed blood flow model, Tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme-coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood compatibility of plasma-deposited Tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions.
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plasma deposited Tetraglyme surfaces greatly reduce total blood protein adsorption contact activation platelet adhesion platelet procoagulant activity and in vitro thrombus deposition
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Mark L Chang, David G. Castner, Buddy D Ratner, Sivaprasad Sukavaneshvar, Thomas A. HorbettAbstract:The ability of tetraethylene glycol dimethyl ether (Tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Wille- brand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagu- lant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that Tetraglyme surfaces strongly resisted the adsorp- tion of all proteins from human plasma. The clotting time in the presence of Tetraglyme surfaces was lengthened com- pared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on tet- raglyme-coated materials, compared with uncoated and Bio- span 1 -coated glass slides. In the in vitro disturbed blood flow model, Tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme- coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood com- patibility of plasma-deposited Tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions. 2007 Wiley Periodicals, Inc. J Biomed Mater Res 81A: 827-837, 2007
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plasma deposition of Tetraglyme inside small diameter tubing optimization and characterization
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Lan Cao, Buddy D Ratner, Thomas A. HorbettAbstract:In this study, a glow discharge plasma deposition system previously used for treating flat substrates was successfully modified and optimized to produce a PEO-like coating on the inner surface of 1-3 mm ID polyethylene tubing by deposition of tetra ethylene glycol dimethyl ether (Tetraglyme). The plasma treatment conditions were varied in order to find operating values that would produce coatings with the ultralow (< 5 ng/cm(2)) fibrinogen adsorption (Gamma(Fg)) previously shown necessary to significantly reduce platelet adhesion. The flow rate of gaseous Tetraglyme monomer, pressure, and plasma generating power were found to be the most important parameters affecting the uniformity and chemical structure of the coating. The coating uniformity and quality were assessed by measuring Gamma(Fg) at positions 1 cm apart along the entire tube and the fraction of C1s carbon that was in an ether bond (ether-carbon ratio) by electron spectroscopy of chemical analysis. Under optimized conditions, Tetraglyme plasma-coated tubes of up to 20 cm in length had ultralow Gamma(Fg). The region of the tube that had ultralow Gamma(Fg) also had C1s ether-carbon ratios that are greater than 50%.
Buddy D Ratner - One of the best experts on this subject based on the ideXlab platform.
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fabrication of submicrometer biomolecular patterns by near field exposure of plasma polymerized Tetraglyme films
Langmuir, 2010Co-Authors: Claire R Hurley, Robert E Ducker, Graham J Leggett, Buddy D RatnerAbstract:Plasma-polymerized Tetraglyme films (PP4G) have been modified by exposure to ultraviolet (UV) light from a frequency-doubled argon ion laser (244 nm) and characterized using X-ray photoelectron spe...
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plasma deposited Tetraglyme surfaces greatly reduce total blood protein adsorption contact activation platelet adhesion platelet procoagulant activity and in vitro thrombus deposition
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Lan Cao, Buddy D Ratner, David G. Castner, Sivaprasad Sukavaneshvar, Mark L Chang, Chi Ying Lee, Thomas A. HorbettAbstract:The ability of tetraethylene glycol dimethyl ether (Tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Willebrand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagulant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that Tetraglyme surfaces strongly resisted the adsorption of all proteins from human plasma. The clotting time in the presence of Tetraglyme surfaces was lengthened compared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on Tetraglyme-coated materials, compared with uncoated and Biospan-coated glass slides. In the in vitro disturbed blood flow model, Tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme-coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood compatibility of plasma-deposited Tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions.
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plasma deposited Tetraglyme surfaces greatly reduce total blood protein adsorption contact activation platelet adhesion platelet procoagulant activity and in vitro thrombus deposition
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Mark L Chang, David G. Castner, Buddy D Ratner, Sivaprasad Sukavaneshvar, Thomas A. HorbettAbstract:The ability of tetraethylene glycol dimethyl ether (Tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Wille- brand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagu- lant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that Tetraglyme surfaces strongly resisted the adsorp- tion of all proteins from human plasma. The clotting time in the presence of Tetraglyme surfaces was lengthened com- pared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on tet- raglyme-coated materials, compared with uncoated and Bio- span 1 -coated glass slides. In the in vitro disturbed blood flow model, Tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme- coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood com- patibility of plasma-deposited Tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions. 2007 Wiley Periodicals, Inc. J Biomed Mater Res 81A: 827-837, 2007
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plasma deposition of Tetraglyme inside small diameter tubing optimization and characterization
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Lan Cao, Buddy D Ratner, Thomas A. HorbettAbstract:In this study, a glow discharge plasma deposition system previously used for treating flat substrates was successfully modified and optimized to produce a PEO-like coating on the inner surface of 1-3 mm ID polyethylene tubing by deposition of tetra ethylene glycol dimethyl ether (Tetraglyme). The plasma treatment conditions were varied in order to find operating values that would produce coatings with the ultralow (< 5 ng/cm(2)) fibrinogen adsorption (Gamma(Fg)) previously shown necessary to significantly reduce platelet adhesion. The flow rate of gaseous Tetraglyme monomer, pressure, and plasma generating power were found to be the most important parameters affecting the uniformity and chemical structure of the coating. The coating uniformity and quality were assessed by measuring Gamma(Fg) at positions 1 cm apart along the entire tube and the fraction of C1s carbon that was in an ether bond (ether-carbon ratio) by electron spectroscopy of chemical analysis. Under optimized conditions, Tetraglyme plasma-coated tubes of up to 20 cm in length had ultralow Gamma(Fg). The region of the tube that had ultralow Gamma(Fg) also had C1s ether-carbon ratios that are greater than 50%.
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glow discharge plasma treatment of polyethylene tubing with Tetraglyme results in ultralow fibrinogen adsorption and greatly reduced platelet adhesion
Journal of Biomedical Materials Research Part A, 2006Co-Authors: Lan Cao, Buddy D Ratner, Sivaprasad Sukavaneshvar, Thomas A. HorbettAbstract:Previous studies from our lab have shown that fibrinogen adsorption (ΓFg) must be reduced below 10 ng/cm2 to significantly reduce platelet adhesion, and that radio frequency glow discharge (RFGD) treatment of polymeric films in the presence of tetraethylene glycol dimethyl ether (Tetraglyme) can reduce ΓFg to the desired ultralow value. In this report, the effects of RFGD coatings of Tetraglyme on the lumenal surface of PE tubing on ΓFg and on blood interactions both in vitro and ex vivo are described. ΓFg on the Tetraglyme-coated PE tubing was reduced to the desired ultralow level (<10 ng/cm2), and we also observed a significant decrease in adsorption of von Willebrand's factor. In vitro platelet adhesion from washed platelet suspensions, platelet rich plasma, or whole blood to Tetraglyme-coated PE tubing was decreased compared to PE, polyurethane, or silicone rubber tubes. In addition, thrombin generation by platelets adherent to Tetraglyme-coated PE was also much less than by platelets adherent to PE. When inserted in an ex vivo carotid artery-carotid artery shunt in sheep, the RFGD Tetraglyme-coated PE exhibited a very low number of adherent platelets compared to heparin-coated, chromic acid-etched, or plain PE. The RFGD Tetraglyme-coated PE tubes exhibited high protein and platelet resistance in vitro, and high platelet resistance ex vivo. The improved hemocompatibility is attributed to the unique chemical structure of RFGD Tetraglyme that makes it highly protein resistant. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Lan Cao - One of the best experts on this subject based on the ideXlab platform.
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plasma deposited Tetraglyme surfaces greatly reduce total blood protein adsorption contact activation platelet adhesion platelet procoagulant activity and in vitro thrombus deposition
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Lan Cao, Buddy D Ratner, David G. Castner, Sivaprasad Sukavaneshvar, Mark L Chang, Chi Ying Lee, Thomas A. HorbettAbstract:The ability of tetraethylene glycol dimethyl ether (Tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Willebrand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagulant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that Tetraglyme surfaces strongly resisted the adsorption of all proteins from human plasma. The clotting time in the presence of Tetraglyme surfaces was lengthened compared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on Tetraglyme-coated materials, compared with uncoated and Biospan-coated glass slides. In the in vitro disturbed blood flow model, Tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme-coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood compatibility of plasma-deposited Tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions.
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plasma deposition of Tetraglyme inside small diameter tubing optimization and characterization
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Lan Cao, Buddy D Ratner, Thomas A. HorbettAbstract:In this study, a glow discharge plasma deposition system previously used for treating flat substrates was successfully modified and optimized to produce a PEO-like coating on the inner surface of 1-3 mm ID polyethylene tubing by deposition of tetra ethylene glycol dimethyl ether (Tetraglyme). The plasma treatment conditions were varied in order to find operating values that would produce coatings with the ultralow (< 5 ng/cm(2)) fibrinogen adsorption (Gamma(Fg)) previously shown necessary to significantly reduce platelet adhesion. The flow rate of gaseous Tetraglyme monomer, pressure, and plasma generating power were found to be the most important parameters affecting the uniformity and chemical structure of the coating. The coating uniformity and quality were assessed by measuring Gamma(Fg) at positions 1 cm apart along the entire tube and the fraction of C1s carbon that was in an ether bond (ether-carbon ratio) by electron spectroscopy of chemical analysis. Under optimized conditions, Tetraglyme plasma-coated tubes of up to 20 cm in length had ultralow Gamma(Fg). The region of the tube that had ultralow Gamma(Fg) also had C1s ether-carbon ratios that are greater than 50%.
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glow discharge plasma treatment of polyethylene tubing with Tetraglyme results in ultralow fibrinogen adsorption and greatly reduced platelet adhesion
Journal of Biomedical Materials Research Part A, 2006Co-Authors: Lan Cao, Buddy D Ratner, Sivaprasad Sukavaneshvar, Thomas A. HorbettAbstract:Previous studies from our lab have shown that fibrinogen adsorption (ΓFg) must be reduced below 10 ng/cm2 to significantly reduce platelet adhesion, and that radio frequency glow discharge (RFGD) treatment of polymeric films in the presence of tetraethylene glycol dimethyl ether (Tetraglyme) can reduce ΓFg to the desired ultralow value. In this report, the effects of RFGD coatings of Tetraglyme on the lumenal surface of PE tubing on ΓFg and on blood interactions both in vitro and ex vivo are described. ΓFg on the Tetraglyme-coated PE tubing was reduced to the desired ultralow level (<10 ng/cm2), and we also observed a significant decrease in adsorption of von Willebrand's factor. In vitro platelet adhesion from washed platelet suspensions, platelet rich plasma, or whole blood to Tetraglyme-coated PE tubing was decreased compared to PE, polyurethane, or silicone rubber tubes. In addition, thrombin generation by platelets adherent to Tetraglyme-coated PE was also much less than by platelets adherent to PE. When inserted in an ex vivo carotid artery-carotid artery shunt in sheep, the RFGD Tetraglyme-coated PE exhibited a very low number of adherent platelets compared to heparin-coated, chromic acid-etched, or plain PE. The RFGD Tetraglyme-coated PE tubes exhibited high protein and platelet resistance in vitro, and high platelet resistance ex vivo. The improved hemocompatibility is attributed to the unique chemical structure of RFGD Tetraglyme that makes it highly protein resistant. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
David G. Castner - One of the best experts on this subject based on the ideXlab platform.
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plasma deposited Tetraglyme surfaces greatly reduce total blood protein adsorption contact activation platelet adhesion platelet procoagulant activity and in vitro thrombus deposition
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Lan Cao, Buddy D Ratner, David G. Castner, Sivaprasad Sukavaneshvar, Mark L Chang, Chi Ying Lee, Thomas A. HorbettAbstract:The ability of tetraethylene glycol dimethyl ether (Tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Willebrand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagulant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that Tetraglyme surfaces strongly resisted the adsorption of all proteins from human plasma. The clotting time in the presence of Tetraglyme surfaces was lengthened compared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on Tetraglyme-coated materials, compared with uncoated and Biospan-coated glass slides. In the in vitro disturbed blood flow model, Tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme-coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood compatibility of plasma-deposited Tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions.
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plasma deposited Tetraglyme surfaces greatly reduce total blood protein adsorption contact activation platelet adhesion platelet procoagulant activity and in vitro thrombus deposition
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Mark L Chang, David G. Castner, Buddy D Ratner, Sivaprasad Sukavaneshvar, Thomas A. HorbettAbstract:The ability of tetraethylene glycol dimethyl ether (Tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Wille- brand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagu- lant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that Tetraglyme surfaces strongly resisted the adsorp- tion of all proteins from human plasma. The clotting time in the presence of Tetraglyme surfaces was lengthened com- pared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on tet- raglyme-coated materials, compared with uncoated and Bio- span 1 -coated glass slides. In the in vitro disturbed blood flow model, Tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme- coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood com- patibility of plasma-deposited Tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions. 2007 Wiley Periodicals, Inc. J Biomed Mater Res 81A: 827-837, 2007
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multivariate surface analysis of plasma deposited Tetraglyme for reduction of protein adsorption and monocyte adhesion
Langmuir, 2003Co-Authors: Mingchao Shen, Buddy D Ratner, David G. Castner, M S Wagner, Thomas A. HorbettAbstract:Adsorbed proteins on implanted biomedical devices mediate platelet and leukocyte adhesion. Radio frequency plasma deposited Tetraglyme (CH3O(CH2CH2O)4CH3), which forms a PEO-like coating, has been shown to resist protein adsorption and monocyte adhesion in vitro. By using different plasma deposition powers (5−80 W), we produced a series of plasma-deposited Tetraglyme surfaces that varied in surface chemistry as measured by electron spectroscopy for chemical analysis (ESCA) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Both fibrinogen and IgG adsorption were increased on surfaces made at high plasma power. Monocyte adhesion correlated linearly with the amount of adsorbed protein. To identify the surface chemical features that contributed to the nonfouling properties of plasma-deposited Tetraglyme, multivariate analysis using partial least squares (PLS) regression was applied. A PLS calibration model based on deposited Tetraglyme samples placed downstream in the plasma reactor successfully ...
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peo like plasma polymerized Tetraglyme surface interactions with leukocytes and proteins in vitro and in vivo studies
Journal of Biomaterials Science-polymer Edition, 2002Co-Authors: Mingchao Shen, Buddy D Ratner, David G. Castner, Laura Martinson, M S Wagner, Thomas A. HorbettAbstract:Polyethylene oxide (PEO) surfaces reduce non-specific protein and cell interactions with implanted biomaterials and may improve their biocompatibility. PEO-like polymerized Tetraglyme surfaces were made by glow discharge plasma deposition onto fluorinated ethylene propylene copolymer (FEP) substrates and were shown to adsorb less than 10 ng/cm2 of fibrinogen in vitro. The ability of the polymerized Tetraglyme surfaces to resist leukocyte adhesion was studied in vitro and in vivo. Polymerized Tetraglyme and FEP were implanted subcutaneously in mice and removed after 1 day or 4 weeks. Histological analysis showed a similar degree of fibrous encapsulation around all of the 4-week implants. Darkly stained wells were present in the fibrous tissues at the tissue-material interface of both FEP and Tetraglyme. Scanning electron micrographs showed that in vivo macrophage adhesion to polymerized Tetraglyme was much higher than to FEP. After 2-hour contact with heparinized whole blood, polymorphonuclear leukocyte (P...
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Inhibition of monocyte adhesion and fibrinogen adsorption on glow discharge plasma deposited tetraethylene glycol dimethyl ether
Journal of Biomaterials Science-polymer Edition, 2001Co-Authors: Mingchao Shen, Buddy D Ratner, Y. Vickie Pan, Matthew S. Wagner, Kip D. Hauch, David G. Castner, Thomas A. HorbettAbstract:Monocytes and macrophages play important roles in host responses to implanted biomedical devices. Monocyte and macrophage interactions with biomaterial surfaces are thought to be mediated by adsorbed adhesive proteins such as fibrinogen and fibronectin. Non-fouling surfaces that minimize protein adsorption may therefore minimize monocyte adhesion, activation, and the foreign body response. Radio-frequency glow discharge plasma deposition (RF-GDPD) of tetraethylene glycol dimethyl ether (Tetraglyme) was used to produce polyethylene oxide (PEO)-like coatings on a fluorinated ethylene-propylene (FEP) surface. Electron spectroscopy for chemical analysis (ESCA) and static time of flight secondary ion mass spectrometry (ToF-SIMS) were used to characterize the surface chemistry of Tetraglyme coating. Fibrinogen adsorption to the Tetraglyme surface was measured with 125I-labeled fibrinogen and ToF-SIMS. Adsorption of fibrinogen to plasma deposited Tetraglyme was less than 10 ng cm-2, a 20-fold decrease compared t...
Sivaprasad Sukavaneshvar - One of the best experts on this subject based on the ideXlab platform.
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plasma deposited Tetraglyme surfaces greatly reduce total blood protein adsorption contact activation platelet adhesion platelet procoagulant activity and in vitro thrombus deposition
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Mark L Chang, David G. Castner, Buddy D Ratner, Sivaprasad Sukavaneshvar, Thomas A. HorbettAbstract:The ability of tetraethylene glycol dimethyl ether (Tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Wille- brand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagu- lant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that Tetraglyme surfaces strongly resisted the adsorp- tion of all proteins from human plasma. The clotting time in the presence of Tetraglyme surfaces was lengthened com- pared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on tet- raglyme-coated materials, compared with uncoated and Bio- span 1 -coated glass slides. In the in vitro disturbed blood flow model, Tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme- coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood com- patibility of plasma-deposited Tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions. 2007 Wiley Periodicals, Inc. J Biomed Mater Res 81A: 827-837, 2007
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plasma deposited Tetraglyme surfaces greatly reduce total blood protein adsorption contact activation platelet adhesion platelet procoagulant activity and in vitro thrombus deposition
Journal of Biomedical Materials Research Part A, 2007Co-Authors: Lan Cao, Buddy D Ratner, David G. Castner, Sivaprasad Sukavaneshvar, Mark L Chang, Chi Ying Lee, Thomas A. HorbettAbstract:The ability of tetraethylene glycol dimethyl ether (Tetraglyme) plasma deposited coatings exhibiting ultralow fibrinogen adsorption to reduce blood activation was studied with six in vitro methods, namely fibrinogen and von Willebrand's factor adsorption, total protein adsorption, clotting time in recalcified plasma, platelet adhesion and procoagulant activity, and whole blood thrombosis in a disturbed flow catheter model. Surface plasmon resonance results showed that Tetraglyme surfaces strongly resisted the adsorption of all proteins from human plasma. The clotting time in the presence of Tetraglyme surfaces was lengthened compared with controls, indicating a lower activation of the intrinsic coagulation cascade. Platelet adhesion and thrombin generation by adherent platelets were greatly reduced on Tetraglyme-coated materials, compared with uncoated and Biospan-coated glass slides. In the in vitro disturbed blood flow model, Tetraglyme plasma coated catheters had 50% less thrombus than did the uncoated catheters. Tetraglyme-coated materials thus had greatly reduced blood interactions as measured with all six methods. The improved blood compatibility of plasma-deposited Tetraglyme is thus not only due to their reduced platelet adhesion and activation, but also to a generalized reduction in blood interactions.
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glow discharge plasma treatment of polyethylene tubing with Tetraglyme results in ultralow fibrinogen adsorption and greatly reduced platelet adhesion
Journal of Biomedical Materials Research Part A, 2006Co-Authors: Lan Cao, Buddy D Ratner, Sivaprasad Sukavaneshvar, Thomas A. HorbettAbstract:Previous studies from our lab have shown that fibrinogen adsorption (ΓFg) must be reduced below 10 ng/cm2 to significantly reduce platelet adhesion, and that radio frequency glow discharge (RFGD) treatment of polymeric films in the presence of tetraethylene glycol dimethyl ether (Tetraglyme) can reduce ΓFg to the desired ultralow value. In this report, the effects of RFGD coatings of Tetraglyme on the lumenal surface of PE tubing on ΓFg and on blood interactions both in vitro and ex vivo are described. ΓFg on the Tetraglyme-coated PE tubing was reduced to the desired ultralow level (<10 ng/cm2), and we also observed a significant decrease in adsorption of von Willebrand's factor. In vitro platelet adhesion from washed platelet suspensions, platelet rich plasma, or whole blood to Tetraglyme-coated PE tubing was decreased compared to PE, polyurethane, or silicone rubber tubes. In addition, thrombin generation by platelets adherent to Tetraglyme-coated PE was also much less than by platelets adherent to PE. When inserted in an ex vivo carotid artery-carotid artery shunt in sheep, the RFGD Tetraglyme-coated PE exhibited a very low number of adherent platelets compared to heparin-coated, chromic acid-etched, or plain PE. The RFGD Tetraglyme-coated PE tubes exhibited high protein and platelet resistance in vitro, and high platelet resistance ex vivo. The improved hemocompatibility is attributed to the unique chemical structure of RFGD Tetraglyme that makes it highly protein resistant. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
