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Zbigniew Adamczyk - One of the best experts on this subject based on the ideXlab platform.
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Mechanisms of Fibrinogen Adsorption on Silica Sensors at Various pHs: Experiments and Theoretical Modeling
Langmuir, 2019Co-Authors: Monika Wasilewska, Zbigniew Adamczyk, Marta Sadowska, Fouzia Boulmedais, Michał CieślaAbstract:The Adsorption kinetics of human serum Fibrinogen at silica substrates was studied using optical waveguide lightmode spectroscopy (OWLS) and quartz crystal microbalance (QCM) techniques. Measurements were performed at pH 3.5, 4, and 7.4 for various ionic strengths. The experimental data were interpreted in terms of a hybrid random sequential Adsorption model. This allowed the mass transfer rate coefficient for the OWLS cell and maximum coverages to be determined at various pHs. The appearance of different, pH-dependent mechanisms of Fibrinogen Adsorption on silica substrates was confirmed. At pH 3.5 the molecules mostly adsorb in the side-on orientation that produces a low maximum coverage of ca. 1 mg m-2. At this pH, the kinetics derived from the OWLS measurements agree with those theoretically predicted using the convective-diffusion theory. In consequence, a comparison of the OWLS and QCM results allows the water factor and the dynamic hydration of Fibrinogen molecules to be determined. At pH 7.4, the OWLS method gives inaccurate kinetic data for the low coverage range. However, the maximum coverage that was equal to ca. 4 mg m-2 agrees with the QCM results and with previous literature results. It is postulated that the limited accuracy of the OWLS method for lower coverage stems from a heterogeneous structure of Fibrinogen monolayers, which consist of side-on and end-on adsorbed molecules. One can expect that the results acquired in this work allow development of a robust procedure for preparing Fibrinogen monolayers of well-controlled coverage and molecule orientation, which can be exploited for efficient immunosensing purposes.
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Fibrinogen Adsorption mechanisms at the gold substrate revealed by qcm d measurements and rsa modeling
Colloids and Surfaces B: Biointerfaces, 2016Co-Authors: Katarzyna Kubiak, Zbigniew Adamczyk, Michal CieślaAbstract:Abstract Adsorption kinetics of Fibrinogen at a gold substrate at various pHs was thoroughly studied using the QCM-D method. The experimental were interpreted in terms of theoretical calculations performed according to the random sequential Adsorption model (RSA). In this way, the hydration functions and water factors of Fibrinogen monolayers were quantitatively evaluated at various pHs. It was revealed that for the lower range of Fibrinogen coverage the hydration function were considerably lower than previously obtained for the silica sensor [33] . The lower hydration of Fibrinogen monolayers on the gold sensor was attributed to its higher roughness. However, for higher Fibrinogen coverage the hydration functions for both sensors became identical exhibiting an universal behavior. By using the hydration functions, the Fibrinogen Adsorption/desorption runs derived from QCM-D measurements were converted to the Γd vs. the time relationships. This allowed to precisely determine the maximum coverage that varied between 1.6 mg m −2 at pH 3.5 and 4.5 mg m −2 at pH 7.4 (for ionic strength of 0.15 M). These results agree with theoretical eRSA modeling and previous experimental data derived by using ellipsometry, OWLS and TIRF. Various Fibrinogen Adsorption mechanisms were revealed by exploiting the maximum coverage data. These results allow one to develop a method for preparing Fibrinogen monolayers of well-controlled coverage and molecule orientation.
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mechanisms of Fibrinogen Adsorption at the silica substrate determined by qcm d measurements
Joint International Conference on Information Sciences, 2015Co-Authors: Katarzyna Kubiak, Zbigniew Adamczyk, Monika WasilewskaAbstract:Abstract Adsorption kinetics of Fibrinogen at a silica substrate was thoroughly studied in situ using the QCM-D method. Because of low dissipation, the Sauerbrey’s equation was used for calculating the wet mass per unit area (wet coverage of the protein). Measurements were done for various bulk suspension concentrations, flow rates and pHs. These experimental data were compared with the theoretical dry coverage data derived from the solution of the mass transfer equation. In this way, the hydration functions and water factors of Fibrinogen monolayers were quantitatively evaluated for various pHs. In the case of pH 7.4 and ionic strength of 0.15 M, the hydration function changed from 0.75 to 0.6 for the dry coverage Γ d equal to 0 and 4 mg m −2 , respectively. Interestingly, for pH 7.4 and 4.5 (ionic strength of 10 −2 M) a minimum of the hydration function appeared at Γ d ca. 2 mg m −2 . Analytical polynomial expressions were formulated for the interpolation of the experimental results. By using the hydration functions, the Fibrinogen Adsorption/desorption runs derived from QCM-D measurements were converted to the Γ d vs. the time relationships. This allowed to precisely determine the maximum coverage that varied between 1.2 mg m −2 at pH 3.5 and 4.2 mg m −2 at pH 7.4 for ionic strength of 0.15 M. These results agree with theoretical modeling and previous experimental data derived by using ellipsometry, OWLS and TIRF. Various Fibrinogen Adsorption mechanisms were revealed by exploiting the maximum coverage data whose validity was also confirmed by the dissipation vs. the dry mass relationships. Beside significance to basic science, these results enable to develop a robust technique, based on the QCM-D measurements, suitable for precisely determining the dry mass of protein monolayers adsorbed under various physicochemical conditions.
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human Fibrinogen Adsorption on positively charged latex particles
Langmuir, 2014Co-Authors: Paulina żeliszewska, Zbigniew Adamczyk, Anna Bratekskicki, Michal CieślaAbstract:Fibrinogen (Fb) Adsorption on positively charged latex particles (average diameter of 800 nm) was studied using the microelectrophoretic and the concentration depletion methods based on AFM imaging. Monolayers on latex were adsorbed from diluted bulk solutions at pH 7.4 and an ionic strength in the range of 10–3 to 0.15 M where Fibrinogen molecules exhibited an average negative charge. The electrophoretic mobility of the latex after controlled Fibrinogen Adsorption was systematically measured. A monotonic decrease in the electrophoretic mobility of Fibrinogen-covered latex was observed for all ionic strengths. The results of these experiments were interpreted according to the three-dimensional electrokinetic model. It was also determined using the concentration depletion method that Fibrinogen Adsorption was irreversible and the maximum coverage was equal to 0.6 mg m–2 for ionic strength 10–3 M and 1.3 mg m–2 for ionic strength 0.15 M. The increase of the maximum coverage was confirmed by theoretical mode...
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mechanisms of Fibrinogen Adsorption at solid substrates
Current Topics in Medicinal Chemistry, 2014Co-Authors: Zbigniew Adamczyk, Paulina żeliszewska, Anna Bratekskicki, Monika WasilewskaAbstract:The aim of this work was to critically review recent results pertinent to Fibrinogen Adsorption at solid/electrolyte interfaces with the emphasis focused on a quantitative analysis of these processes in terms of the electrostatic interactions. Accordingly, in the first part, the primary chemical structure of Fibrinogen is analyzed. Physicochemical data pertinent to the bulk properties derived from hydrodynamic, dynamic light scattering and micro-electrophoretic measurements aided by theoretical modeling are discussed. Possible conformations and the effective charge distribution over the Fibrinogen molecule for various pH an ionic strength are defined, especially the semi-collapsed conformation prevailing at physiological conditions. Adsorption kinetics of Fibrinogen at hydrophilic and hydrophobic (polymer modified) substrates determined by various techniques is described. Adsorption at polymeric carrier particles, pertinent to immunological assays, studied in terms of electrokinetic and concentration depletion methods, are also considered. The reversibility of Adsorption, Fibrinogen molecule orientations and maximum coverages are thoroughly discussed. The stability of Fibrinogen monolayers formed at these carrier particles in respect to pH and ionic strength cyclic changes is also discussed. In the final section interactions and deposition of model colloid particles on Fibrinogen monolayers are analyzed which allows one to derive valuable information about molecule orientations. Based on the physicochemical data, Adsorption kinetics and colloid particle deposition measurements, probable Adsorption mechanisms of Fibrinogen on solid/electrolyte interfaces are defined.
Monika Wasilewska - One of the best experts on this subject based on the ideXlab platform.
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Mechanisms of Fibrinogen Adsorption on Silica Sensors at Various pHs: Experiments and Theoretical Modeling
Langmuir, 2019Co-Authors: Monika Wasilewska, Zbigniew Adamczyk, Marta Sadowska, Fouzia Boulmedais, Michał CieślaAbstract:The Adsorption kinetics of human serum Fibrinogen at silica substrates was studied using optical waveguide lightmode spectroscopy (OWLS) and quartz crystal microbalance (QCM) techniques. Measurements were performed at pH 3.5, 4, and 7.4 for various ionic strengths. The experimental data were interpreted in terms of a hybrid random sequential Adsorption model. This allowed the mass transfer rate coefficient for the OWLS cell and maximum coverages to be determined at various pHs. The appearance of different, pH-dependent mechanisms of Fibrinogen Adsorption on silica substrates was confirmed. At pH 3.5 the molecules mostly adsorb in the side-on orientation that produces a low maximum coverage of ca. 1 mg m-2. At this pH, the kinetics derived from the OWLS measurements agree with those theoretically predicted using the convective-diffusion theory. In consequence, a comparison of the OWLS and QCM results allows the water factor and the dynamic hydration of Fibrinogen molecules to be determined. At pH 7.4, the OWLS method gives inaccurate kinetic data for the low coverage range. However, the maximum coverage that was equal to ca. 4 mg m-2 agrees with the QCM results and with previous literature results. It is postulated that the limited accuracy of the OWLS method for lower coverage stems from a heterogeneous structure of Fibrinogen monolayers, which consist of side-on and end-on adsorbed molecules. One can expect that the results acquired in this work allow development of a robust procedure for preparing Fibrinogen monolayers of well-controlled coverage and molecule orientation, which can be exploited for efficient immunosensing purposes.
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mechanisms of Fibrinogen Adsorption at the silica substrate determined by qcm d measurements
Joint International Conference on Information Sciences, 2015Co-Authors: Katarzyna Kubiak, Zbigniew Adamczyk, Monika WasilewskaAbstract:Abstract Adsorption kinetics of Fibrinogen at a silica substrate was thoroughly studied in situ using the QCM-D method. Because of low dissipation, the Sauerbrey’s equation was used for calculating the wet mass per unit area (wet coverage of the protein). Measurements were done for various bulk suspension concentrations, flow rates and pHs. These experimental data were compared with the theoretical dry coverage data derived from the solution of the mass transfer equation. In this way, the hydration functions and water factors of Fibrinogen monolayers were quantitatively evaluated for various pHs. In the case of pH 7.4 and ionic strength of 0.15 M, the hydration function changed from 0.75 to 0.6 for the dry coverage Γ d equal to 0 and 4 mg m −2 , respectively. Interestingly, for pH 7.4 and 4.5 (ionic strength of 10 −2 M) a minimum of the hydration function appeared at Γ d ca. 2 mg m −2 . Analytical polynomial expressions were formulated for the interpolation of the experimental results. By using the hydration functions, the Fibrinogen Adsorption/desorption runs derived from QCM-D measurements were converted to the Γ d vs. the time relationships. This allowed to precisely determine the maximum coverage that varied between 1.2 mg m −2 at pH 3.5 and 4.2 mg m −2 at pH 7.4 for ionic strength of 0.15 M. These results agree with theoretical modeling and previous experimental data derived by using ellipsometry, OWLS and TIRF. Various Fibrinogen Adsorption mechanisms were revealed by exploiting the maximum coverage data whose validity was also confirmed by the dissipation vs. the dry mass relationships. Beside significance to basic science, these results enable to develop a robust technique, based on the QCM-D measurements, suitable for precisely determining the dry mass of protein monolayers adsorbed under various physicochemical conditions.
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mechanisms of Fibrinogen Adsorption at solid substrates
Current Topics in Medicinal Chemistry, 2014Co-Authors: Zbigniew Adamczyk, Paulina żeliszewska, Anna Bratekskicki, Monika WasilewskaAbstract:The aim of this work was to critically review recent results pertinent to Fibrinogen Adsorption at solid/electrolyte interfaces with the emphasis focused on a quantitative analysis of these processes in terms of the electrostatic interactions. Accordingly, in the first part, the primary chemical structure of Fibrinogen is analyzed. Physicochemical data pertinent to the bulk properties derived from hydrodynamic, dynamic light scattering and micro-electrophoretic measurements aided by theoretical modeling are discussed. Possible conformations and the effective charge distribution over the Fibrinogen molecule for various pH an ionic strength are defined, especially the semi-collapsed conformation prevailing at physiological conditions. Adsorption kinetics of Fibrinogen at hydrophilic and hydrophobic (polymer modified) substrates determined by various techniques is described. Adsorption at polymeric carrier particles, pertinent to immunological assays, studied in terms of electrokinetic and concentration depletion methods, are also considered. The reversibility of Adsorption, Fibrinogen molecule orientations and maximum coverages are thoroughly discussed. The stability of Fibrinogen monolayers formed at these carrier particles in respect to pH and ionic strength cyclic changes is also discussed. In the final section interactions and deposition of model colloid particles on Fibrinogen monolayers are analyzed which allows one to derive valuable information about molecule orientations. Based on the physicochemical data, Adsorption kinetics and colloid particle deposition measurements, probable Adsorption mechanisms of Fibrinogen on solid/electrolyte interfaces are defined.
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mechanisms of Fibrinogen Adsorption at solid substrates at lower ph
Langmuir, 2013Co-Authors: Michal Cieśla, Zbigniew Adamczyk, Jakub Barbasz, Monika WasilewskaAbstract:Adsorption of Fibrinogen was theoretically studied using the three-dimensional random sequential Adsorption (RSA) model. Fibrinogen molecule shape was approximated by the bead model considering the presence of flexible side arms. Various cases were considered inter alia, the side-on Adsorption mechanisms and the simultaneous side-on/end-on Adsorption mechanism. The latter mechanisms is pertinent to Fibrinogen Adsorption at lower pH (below isoelectric point of 5.8) where the entire molecule is positively charged. Extensive calculations enabled one to determine the jamming surface concentration (coverage) of molecules adsorbed under the side-on and end-on orientations as well as the total coverage. For the simultaneous side-on/end-on model the maximum surface concentration was 7.29 × 103 μm–2 corresponding to the protein coverage of 4.12 mg m–2 (without considering hydration). Additionally, the surface blocking functions for different Adsorption regimes were determined and analytically approximated for the ...
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Fibrinogen Adsorption on mica studied by afm and in situ streaming potential measurements
Langmuir, 2011Co-Authors: Monika Wasilewska, Zbigniew AdamczykAbstract:Adsorption of Fibrinogen from aqueous solutions on mica was studied using AFM and in situ streaming potential measurements. In the first stage, bulk physicochemical properties of Fibrinogen and the mica substrate were characterized for various ionic strength and pH. The zeta potential and number of uncompensated (electrokinetic) charges on the protein surfaces were determined from microelectrophoretic measurements. Analogously, using streaming potential measurements, the electrokinetic charge density of mica was determined for pH range 3−10 and the NaCl background electrolyte concentration of 10−3 and 10−2 M. Next, the kinetics of Fibrinogen Adsorption at pH 3.5 and 7.4 in the diffusion cell was studied using a direct AFM determination of the number of molecules per unit area of the mica substrate. Then, streaming potential measurements were performed to determine the apparent zeta potential of Fibrinogen-covered mica for different pH and ionic strength in terms of its surface concentration. A quantitativ...
Michal Cieśla - One of the best experts on this subject based on the ideXlab platform.
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Fibrinogen Adsorption mechanisms at the gold substrate revealed by qcm d measurements and rsa modeling
Colloids and Surfaces B: Biointerfaces, 2016Co-Authors: Katarzyna Kubiak, Zbigniew Adamczyk, Michal CieślaAbstract:Abstract Adsorption kinetics of Fibrinogen at a gold substrate at various pHs was thoroughly studied using the QCM-D method. The experimental were interpreted in terms of theoretical calculations performed according to the random sequential Adsorption model (RSA). In this way, the hydration functions and water factors of Fibrinogen monolayers were quantitatively evaluated at various pHs. It was revealed that for the lower range of Fibrinogen coverage the hydration function were considerably lower than previously obtained for the silica sensor [33] . The lower hydration of Fibrinogen monolayers on the gold sensor was attributed to its higher roughness. However, for higher Fibrinogen coverage the hydration functions for both sensors became identical exhibiting an universal behavior. By using the hydration functions, the Fibrinogen Adsorption/desorption runs derived from QCM-D measurements were converted to the Γd vs. the time relationships. This allowed to precisely determine the maximum coverage that varied between 1.6 mg m −2 at pH 3.5 and 4.5 mg m −2 at pH 7.4 (for ionic strength of 0.15 M). These results agree with theoretical eRSA modeling and previous experimental data derived by using ellipsometry, OWLS and TIRF. Various Fibrinogen Adsorption mechanisms were revealed by exploiting the maximum coverage data. These results allow one to develop a method for preparing Fibrinogen monolayers of well-controlled coverage and molecule orientation.
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human Fibrinogen Adsorption on positively charged latex particles
Langmuir, 2014Co-Authors: Paulina żeliszewska, Zbigniew Adamczyk, Anna Bratekskicki, Michal CieślaAbstract:Fibrinogen (Fb) Adsorption on positively charged latex particles (average diameter of 800 nm) was studied using the microelectrophoretic and the concentration depletion methods based on AFM imaging. Monolayers on latex were adsorbed from diluted bulk solutions at pH 7.4 and an ionic strength in the range of 10–3 to 0.15 M where Fibrinogen molecules exhibited an average negative charge. The electrophoretic mobility of the latex after controlled Fibrinogen Adsorption was systematically measured. A monotonic decrease in the electrophoretic mobility of Fibrinogen-covered latex was observed for all ionic strengths. The results of these experiments were interpreted according to the three-dimensional electrokinetic model. It was also determined using the concentration depletion method that Fibrinogen Adsorption was irreversible and the maximum coverage was equal to 0.6 mg m–2 for ionic strength 10–3 M and 1.3 mg m–2 for ionic strength 0.15 M. The increase of the maximum coverage was confirmed by theoretical mode...
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mechanisms of Fibrinogen Adsorption at solid substrates at lower ph
Langmuir, 2013Co-Authors: Michal Cieśla, Zbigniew Adamczyk, Jakub Barbasz, Monika WasilewskaAbstract:Adsorption of Fibrinogen was theoretically studied using the three-dimensional random sequential Adsorption (RSA) model. Fibrinogen molecule shape was approximated by the bead model considering the presence of flexible side arms. Various cases were considered inter alia, the side-on Adsorption mechanisms and the simultaneous side-on/end-on Adsorption mechanism. The latter mechanisms is pertinent to Fibrinogen Adsorption at lower pH (below isoelectric point of 5.8) where the entire molecule is positively charged. Extensive calculations enabled one to determine the jamming surface concentration (coverage) of molecules adsorbed under the side-on and end-on orientations as well as the total coverage. For the simultaneous side-on/end-on model the maximum surface concentration was 7.29 × 103 μm–2 corresponding to the protein coverage of 4.12 mg m–2 (without considering hydration). Additionally, the surface blocking functions for different Adsorption regimes were determined and analytically approximated for the ...
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mechanisms of Fibrinogen Adsorption at solid substrates
Langmuir, 2011Co-Authors: Zbigniew Adamczyk, Jakub Barbasz, Michal CieślaAbstract:Adsorption of Fibrinogen, modeled as a linear chain of touching beads of various sizes, was theoretically studied using the random sequential Adsorption (RSA) model. The Adsorption process was assumed to consist of two steps: (i) formation of an irreversibly bound Fibrinogen monolayer under the side-on orientation, which is independent of the bulk protein concentration and (ii) formation of the reversibly bound, end-on monolayer, whose coverage was dependent on the bulk concentration. Calculation based on the RSA model showed that the maximum surface concentration of the end-on (reversible) monolayer equals N⊥∞ = 6.13 × 103 μm–2 which is much larger than the previously found value for the side-on (irreversible) monolayer, equal to N∞ = 2.27 × 103 μm–2. Hence, the maximum surface concentration of Fibrinogen in both orientations is determined to be 8.40 × 103 μm–2 corresponding to the protein coverage of 5.70 mg m–2 assuming 20% hydration. Additionally, the surface blocking function (ASF) was determined for...
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kinetics of Fibrinogen Adsorption on hydrophilic substrates
Langmuir, 2010Co-Authors: Zbigniew Adamczyk, Jakub Barbasz, Michal CieślaAbstract:Irreversible side-on Adsorption of Fibrinogen, modeled as a linear chain of touching beads of various size, was studied theoretically using the random sequential Adsorption (RSA) model. Numerical simulation of the Monte Carlo type enabled one to determine the dependence of the surface blocking function (available surface function) on the protein coverage. These numerical results were interpolated using analytical functions based on a polynomial expansion. The dependence of the jamming coverage on the size of the simulation area was also determined. By an extrapolation of these results to the infinite area size, the maximum surface concentration of Fibrinogen for the side-on Adsorption was determined to be 2.26 × 103 μm−2. This corresponds to a jamming coverage θ∞ of 0.29. It was shown that the blocking function can well be approximated in the limit of high coverage by the dependence C(θ∞ − θ)4. Using this interpolating expression, the kinetics of Fibrinogen Adsorption under convection and diffusion transp...
Thomas A. Horbett - One of the best experts on this subject based on the ideXlab platform.
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Fibrinogen Adsorption to biomaterials
Journal of biomedical materials research. Part A, 2018Co-Authors: Thomas A. HorbettAbstract:Fibrinogen (Fg) Adsorption is an important mechanism underlying cell adhesion to biomaterials and was the major focus of the author's research career. This article summarizes our work on Fg Adsorption, with citations of related work as appropriate. The molecular properties of Fg that promote Adsorption and cell adhesion will be described. In addition, the Adsorption behavior of Fg from buffer, binary solutions with other proteins, and blood plasma will be discussed, including the Vroman effect. Studies of platelet adhesion to surfaces preadsorbed with blood plasmas selectively deficient in Fg, vitronectin (Vn), fibronectin (Fn), or von Willebrand's factor (vWf) will be reviewed. These studies clearly showed a major role for Fg in platelet adhesion under static conditions and both Fg and vWf for adhesion from flowing suspensions, but no significant role for Vn or Fn. However, it was also shown that platelet adhesion was poorly correlated with the total amount of adsorbed Fg, but very well correlated with the binding of antibodies specific to the cell binding domains of Fg. A brief overview of nonfouling surfaces for prevention of Fg Adsorption will be given. A more extensive discussion of structural changes in Fg after its Adsorption is included, including changes detected with both physicochemical and biological methods. A short discussion of the state of the art of structural determination of adsorbed proteins with computational methods is also given. A final section identifies Fg Adsorption as the single most important event determining the biocompatibility of implants in soft tissue and in blood. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 2777-2788, 2018.
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blood compatibility of surfaces with superlow protein Adsorption
Biomaterials, 2008Co-Authors: Zheng Zhang, Shengfu Chen, Thomas A. Horbett, Min Zhang, Buddy D Ratner, Shaoyi JiangAbstract:Abstract In this work, five self-assembled monolayers (SAMs) and three polymeric brushes with very low Fibrinogen Adsorption were prepared. The five SAMs are oligo(ethylene glycol) (OEG), phosphorylcholine (PC), oligo(phosphorylcholine) (OPC), and two mixed positively and negatively charged SAMs of SO3−/N+(CH3)3 (SA/TMA) and COO−/N+(CH3)3 (CA/TMA). Three polymer brushes were prepared on gold surfaces via surface-initiated atom transfer radical polymerization (ATRP) using three monomers, sulfobetaine methacrylate (SBMA), carboxybetaine methacrylate (CBMA), and oligo(ethylene glycol) methyl ether methacrylate (OEGMA). Surface plasmon resonance (SPR) measurements show that although all of these surfaces are “nonfouling” to Fibrinogen Adsorption from buffer solution, their protein Adsorption from undiluted human blood plasma varies widely. Polymer brushes exhibit much lower protein Adsorption from plasma than any of the five SAMs tested. However, platelet adhesion measurements on plasma-preadsorbed surfaces show that all of these surfaces have very low platelet adhesion. Clotting time measurements using recalcified platelet poor plasma (PPP) incubation with the eight types of surfaces show that they do not shorten clotting times. Linear polymers of polySBMA and polyCBMA with similar molecular weights were also synthesized and characterized. In the presence of polyCBMA linear polymers, the clotting time of PPP was prolonged and increased with the concentration of the polymer, while no anticoagulant activity was observed for the polySBMA or PEG polymers. The unique anticoagulant activity of polyCBMA, as well as its high plasma protein Adsorption resistance, makes polyCBMA a candidate for blood-contacting applications.
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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
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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...
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human plasma Fibrinogen Adsorption and platelet adhesion to polystyrene
Journal of Biomedical Materials Research, 1999Co-Authors: Weibor Tsai, J M Grunkemeier, Thomas A. HorbettAbstract:The purpose of this study was to further investigate the role of Fibrinogen adsorbed from plasma in mediating platelet adhesion to polymeric biomaterials. Polystyrene was used as a model hydrophobic polymer; i.e., we expected that the role of Fibrinogen in platelet adhesion to polystyrene would be representative of other hydrophobic polymers. Platelet adhesion was compared to both the amount and conformation of adsorbed Fibrinogen. The strategy was to compare platelet adhesion to surfaces preadsorbed with normal, aFibrinogenemic, and Fibrinogen-replenished aFibrinogenemic plasmas. Platelet adhesion was determined by the lactate dehydrogenase (LDH) method, which was found to be closely correlated with adhesion of 111In-labeled platelets. Fibrinogen Adsorption from aFibrinogenemic plasma to polystyrene (Immulon I(R)) was low and <10 ng/cm2. Platelet adhesion was absent on surfaces preadsorbed with aFibrinogenemic plasma when the residual Fibrinogen was low enough (<60 microg/mL). Platelet adhesion was restored on polystyrene preadsorbed with Fibrinogen-replenished aFibrinogenemic plasma. Addition of even small, subnormal concentrations of Fibrinogen to aFibrinogenemic plasma greatly increased platelet adhesion. In addition, surface-bound Fibrinogen's ability to mediate platelet adhesion was different, depending on the plasma concentration from which Fibrinogen was adsorbed. These differences correlated with changes in the binding of a monoclonal antibody that binds to the Aalpha chain RGDS (572-575), suggesting alteration in the conformation or orientation of the adsorbed Fibrinogen. Platelet adhesion to polystyrene preadsorbed with blood plasma thus appears to be a strongly bivariate function of adsorbed Fibrinogen, responsive to both low amounts and altered states of the adsorbed molecule.
Shaoyi Jiang - One of the best experts on this subject based on the ideXlab platform.
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blood compatibility of surfaces with superlow protein Adsorption
Biomaterials, 2008Co-Authors: Zheng Zhang, Shengfu Chen, Thomas A. Horbett, Min Zhang, Buddy D Ratner, Shaoyi JiangAbstract:Abstract In this work, five self-assembled monolayers (SAMs) and three polymeric brushes with very low Fibrinogen Adsorption were prepared. The five SAMs are oligo(ethylene glycol) (OEG), phosphorylcholine (PC), oligo(phosphorylcholine) (OPC), and two mixed positively and negatively charged SAMs of SO3−/N+(CH3)3 (SA/TMA) and COO−/N+(CH3)3 (CA/TMA). Three polymer brushes were prepared on gold surfaces via surface-initiated atom transfer radical polymerization (ATRP) using three monomers, sulfobetaine methacrylate (SBMA), carboxybetaine methacrylate (CBMA), and oligo(ethylene glycol) methyl ether methacrylate (OEGMA). Surface plasmon resonance (SPR) measurements show that although all of these surfaces are “nonfouling” to Fibrinogen Adsorption from buffer solution, their protein Adsorption from undiluted human blood plasma varies widely. Polymer brushes exhibit much lower protein Adsorption from plasma than any of the five SAMs tested. However, platelet adhesion measurements on plasma-preadsorbed surfaces show that all of these surfaces have very low platelet adhesion. Clotting time measurements using recalcified platelet poor plasma (PPP) incubation with the eight types of surfaces show that they do not shorten clotting times. Linear polymers of polySBMA and polyCBMA with similar molecular weights were also synthesized and characterized. In the presence of polyCBMA linear polymers, the clotting time of PPP was prolonged and increased with the concentration of the polymer, while no anticoagulant activity was observed for the polySBMA or PEG polymers. The unique anticoagulant activity of polyCBMA, as well as its high plasma protein Adsorption resistance, makes polyCBMA a candidate for blood-contacting applications.
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protein interactions with oligo ethylene glycol oeg self assembled monolayers oeg stability surface packing density and protein Adsorption
Journal of Biomaterials Science-polymer Edition, 2007Co-Authors: Shengfu Chen, Shaoyi JiangAbstract:We present a study of protein Adsorption on oligo(ethylene glycol) (OEG) self-assembled monolayers (SAMs) at a range of OEG surface densities. OEG SAMs were formed in mixed ethanol and water solutions at different assembly temperatures to adjust the packing density of EG4-SAMs. These SAMs were characterized using X-ray photoelectron spectroscopy (XPS). Fibrinogen Adsorption on these surfaces was measured by a surface plasmon resonance (SPR) sensor at different temperatures. This work is aimed at addressing three important issues for protein–OEG interactions, i.e., (i) OEG stability, (ii) the correlation between OEG surface densities and surface non-fouling properties, and (iii) protein Adsorption on OEG surfaces at different temperatures.
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superlow fouling sulfobetaine and carboxybetaine polymers on glass slides
Langmuir, 2006Co-Authors: Zheng Zhang, Shengfu Chen, Timothy Chao, Shaoyi JiangAbstract:This work describes the superlow fouling properties of glass slides grafted with zwitterionic polymers to highly resist the Adsorption of proteins and the adhesion of mammalian cells. Glass slides were first silanized using 2-bromo-2-methyl-N-3-[(triethoxysilyl)propyl]propanamide (BrTMOS). Two zwitterionic polymers, poly(sulfobetaine methacrylate) (polySBMA) and poly(carboxybetaine methacrylate) (polyCBMA), were then grafted from the silanized glass substrates using the atom-transfer radical polymerization (ATRP) method. X-ray photoelectron spectroscopy (XPS) was used to analyze the surfaces of the silanized glass substrates and the substrates grafted with the polymers. An enzyme-linked immonosobrbent assay (ELISA) using polyclonal antibodies was used to measure Fibrinogen Adsorption on these surfaces. The surfaces with polySBMA or polyCBMA layers were shown to reduce Fibrinogen Adsorption to a level comparable with that of Adsorption on poly(ethylene glycol)-like films. Bovine aortic endothelial cells (B...
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surface grafted sulfobetaine polymers via atom transfer radical polymerization as superlow fouling coatings
Journal of Physical Chemistry B, 2006Co-Authors: Zheng Zhang, Shengfu Chen, Yung Chang, Shaoyi JiangAbstract:One of the sulfobetaine methacrylate (SBMA) monomers, N-(3-sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammonium betaine, was polymerized onto initiator-covered gold surfaces using atom transfer radical polymerization (ATRP) to form uniform polymer brushes. Self-assembled monolayers (SAMs) with ATRP initiators were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The thickness of grafted poly(SBMA) films was measured by ellipsometry. Fibrinogen Adsorption on poly(SBMA) grafted surfaces was measured with a surface plasmon resonance (SPR) sensor. Two approaches were compared to graft ATRP initiators onto gold surfaces for surface polymerization and subsequent protein Adsorption on these polymer grafted surfaces. The first was to prepare a SAM from ω-mercaptoundecyl bromoisobutyrate onto a gold surface. Superlow fouling surfaces with well-controlled poly(SBMA) brushes were achieved using this approach (e.g., Fibrinogen Adsorption <0.3 ng/cm2). The second approach w...