共查询到20条相似文献,搜索用时 31 毫秒
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聚苯乙烯—g—聚氧乙烯接枝共聚物表面阻抗蛋白质吸附的研究 总被引:1,自引:2,他引:1
利用放射性磺标记技术研究了血浆蛋白质-缓冲溶液体系在聚苯乙烯-g-聚氧乙烯接枝共聚物表面的等温吸附和吸附动力学,材料表面蛋白质等温吸附量或平衡吸附量随表面PEO含量增加而下降,吸附量最低值小于0.25μg.cm^-2;同时探讨了材料表面“梳状”结构对材料表面PEO侧链阻抗蛋白质性能的影响。 相似文献
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聚氧乙烯功能基复合修饰聚氨酯合成及其血液相容性研究 (Ⅱ)──聚氨酯-接枝-聚氧乙烯氨基酸衍生物 总被引:4,自引:0,他引:4
采用以磺酸基为末端基的聚氧乙烯(PEO)接枝聚醚氨酯和氨基酸反应,将赖氨酸(Lys)和酪氨酸(Tyr)通过PEO为"间隔臂"固定在聚醚氨酯上,制备了氨基酸和PEO复合修饰的聚醚氨酯PEU-g-PEO-SO2Lys和PEU-g-PEO-SO2Tyr.通过血小板粘附试验对材料的体外抗凝血性进行了初步评价.研究结果表明,采用具有选择性吸附纤溶酶原功能的赖氨酸和PEO复合修饰聚氨酯,不仅减少了材料表面血小板粘附量,而且减少了材料表面血栓的形成量. 相似文献
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采用以碘酸基为末端基的聚氧乙烯(PEO)接枝聚醚氨酯和氨基酸反应,将赖氨酸(Lys)和酪氨酸(Tyr)通过PEO为“间隔臂”固定在聚醚氨酯上,制备了氨基酸和PEO复合修饰的聚醚氨酯PEU-g-PEO-SO2Lys和PEU-g-PEO-SO2Tyr。通过血小板粘附试验对材料的体外抗凝血性进行 了初步评价。研究结果表明,采用具有选择性吸附纤溶酶原功能的赖氨酸和PEO复合修聚氨酯,不仅减少了材料表面血小板粘附量,而且减少了材料表面栓的形成量。 相似文献
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蛋白质的界面吸附及其生物活性因它在构建生物传感、生物电子器件和生物燃料电池等方面具有重要的作用而倍受关注.对此,界面电场是吸附的一个重要影响因素,它能明显地影响蛋白质分子在材料界面的吸附量、分子构象以及分子定向.本文应用电化学方法和红外光谱技术研究了血红蛋白在三维多孔金膜电极上的吸附动力学及其生物活性随界面电场的变化关系.结果表明,由界面电场产生的过量表面电荷可借助与蛋白质分子之间的静电作用加速蛋白质分子在电极表面的吸附,提高其吸附量;但是,过高的界面电场将破坏吸附蛋白质的构象以及降低它还原过氧化氢的催化活性;只有在零电荷电位下,吸附在电极表面的血红蛋白才能保持其天然的构象和生物催化活性.本研究将为生物传感器、生物电子器件和生物燃料电池的构建提供理论依据,加深对荷电生物界面上生物分子界面行为的认识. 相似文献
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一定pH值和一定浓度下,蛋白质与表面活性剂相互作用形成复合物产生沉淀。作者利用这一原理,研究了肌酸激酶对表面活性剂的吸附关系,并据此发展了滴定法和表面张力法两种简便测定蛋白质对表面活性剂吸附量的方法。 相似文献
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聚苯乙烯—g—(十八烷基聚氧乙烯)阻抗血小板粘附的研究 总被引:4,自引:3,他引:4
近年来,随着高分子科学、医学、材料科学的发展和相互渗透,高分子材料成为生物医用材料的研究重点.然而,和其它材料一样,当合成高分子材料和血液接触时,血浆蛋白质在材料表面迅速形成一层蛋白质吸附层,直接影响血小板和材料表面的相互作用,导致血寸板的粘附、活化和释放,并进一步引起血小板的凝血反应,严重地限制了高分子材料在临床上的应用.聚氧乙烯(PEO)由于其良好的生物惰性,成为改善高分子材料血液相容性的理范材料.人们通过多种手段将PEO修饰到材料表面,得到了具有良好的血液相容性的高分于医用材料[".同时,人们… 相似文献
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J. Serra J. Puig A. Martín F. Galisteo MaJ Gálvez R. Hidalgo-Alvarez 《Colloid and polymer science》1992,270(6):574-583
An experimental investigation on the adsorption of immuno -globulin molecules on polystyrene microspheres is described. Three different IgG samples were adsorbed on latex particles. One was of polyclonal nature with a broad range of isoelectric points (6.1–8.7), whereas the other samples were of monoclonal nature, Mab 1 and Mab 2 with i.e.p. of (5.65±0.15) and (7.7±0.1), respectively. Adsorption isotherms at different ionic strengths and pH were performed. Most of the adsorption isotherms showed well-defined plateaus. Because of instability in solution of Mab 2 in the pH values of 7 and 8, no plateau values were found in the adsorption isotherms at both pH-values. Maximum protein adsorption was found around the i.e.p. of the protein. According to the findings, the IgG adsorption on polystyrene surface is strongly irreversible with respect to pH changes. The ionic-strength changes, however, exert a pronounced effect on the adsorption-desorption processes of IgG on negatively charged polystyrene surface. Also, electrophoresis experiments were performed to gain information on the electrostatic interaction between the IgG molecules and the PS latex. With increasing the adsorbed amount of IgG the absolute value of mobility decreases to reach a plateau value. The isoelectric pH of the IgG-PS complex is always smaller than the i.e.p. of the dissolved IgG, indicating that the PS surface charge must partly compensate the positive charge on the protein. Finally, the colloidal stability of the rabbit IgG/PS complex is always very low, whereas the Mab/PS complexes are very stable when the charge electrokinetically mobilized by these systems is very large. 相似文献
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Chi Fang Ting Xiong Jie Hou Jing Wei Gu Mei Hu Sheng 《Journal of Dispersion Science and Technology》2013,34(4):604-610
Amidoxime (AO)/amine co-functionalized polypropylene fiber adsorbents were prepared. The all-polymeric structures were characterized by using Fourier transform infrared spectroscopy (FTIR), optical microscope, contact angle meter and electron spin resonance (ESR) analysis methods, confirming the grafting, modification, and amidoximation stages gravimetrically, spectroscopically, and visually. The properties for the removal of uranyl(VI) from aqueous solutions were investigated. For amidoxime (AO) fiber, high adsorption rate was observed within the first 30 minutes and the plateau value of 40.6% uranium loading (0.0812 mg/g) was reached at around 30 minutes. The adsorption equilibrium for AO/amine fiber was attained within 20 minutes, resulting in the adsorption of 92.6% uranium loading (0.185 mg/g). The percentage of adsorption increases with increasing pH value (2–6), reaches a maximum at pH 6.0 and then remains almost constant for AO/amine fiber, whereas reduces slightly for AO fiber. 相似文献
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Patrick Vermette Virginie Gauvreau Michel Pzolet Gatan Laroche 《Colloids and surfaces. B, Biointerfaces》2003,29(4):285-295
Dipalmitoylphosphatidylcholine (DPPC) monolayers were deposited onto a germanium attenuated total reflectance (ATR) crystal using the Langmuir–Blodgett technique. The DPPC-coated crystal was then exposed to human serum albumin or human fibrinogen solutions while measuring the protein adsorption by recording FTIR spectra. The effect of the zwitterionic nature of the DPPC polar headgroup towards protein adsorption has been ascertained by exposing either the phospholipid headgroup or the acyl chains to the protein solution; this was possible by the use of a silanized or a bare germanium crystal. Calibration curves have been made to measure the protein surface concentrations. After 3 h, the albumin surface concentration on DPPC monolayers was about three times higher when the proteins were exposed to the lipid acyl chains instead of the polar headgroups (e.g. 3 vs. 1 μg cm−2). As for fibrinogen (FGN) adsorption, when the lipid polar headgroups were exposed to the protein solution, the FGN adsorption was low reaching a maximum value of 0.5 μg cm−2. When interacting with the lipid acyl chains, the FGN adsorption reached a plateau at a value of 2.1 μg cm−2 after 3 h. Clearly, both albumin and FGN showed a low tendency to adsorb on surfaces where the lipid polar headgroups are exposed toward the protein solution. 相似文献
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Kamyshny A. Relkin P. Lagerge S. Partyka S. Magdassi S. 《Journal of Thermal Analysis and Calorimetry》2003,71(1):263-272
Differential scanning calorimetry (DSC) and isothermal calorimetric batch technique were used to monitor the heat-induced structural changes and adsorption properties of human immunoglobulin G (IgG), in native and hydrophobized states. The transition temperature (T
max) and enthalpy of heat-induced conformational changes (cal
H) of IgG in solution as well as the enthalpy change accompanying the adsorption of IgG onto hydrophilic silica (ads
H), were shown to depend on the degree of the protein hydrophobicity (number of covalently attached alkyl chains). The adsorption enthalpy for all forms of IgG at all surface concentrations was found to be endothermic, that is the process is entropy driven. Factors affecting the IgG adsorption onto silica are discussed.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
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Experimental results are presented on the adsorption of sodium alkyl sulfate homologues (nC = 8-14) at the air/solution interface. The adsorption isotherms calculated from equilibrium surface-tension vs concentration data and the critical micelle concentration change regularly with the length of the alkyl chain; the odd/even effect was not observed. The isotherms were analyzed using a model-independent approach. The analysis indicates that the total driving force of adsorption reaches a plateau value and becomes constant in the function of the adsorbed amount in the case of each homologue. With the use of different electrostatic models, it was demonstrated that this behavior is consistent with a saturation-type hydrophobic driving-force contribution, which can be interpreted by the development of a liquidlike alkane environment in the adsorbed layer above a "critical" adsorbed amount. 相似文献
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Shaohua Lu Joy T. Kunjappu P. Somasundaran Lei Zhang 《Colloids and surfaces. A, Physicochemical and engineering aspects》2008,324(1-3):65-70
Adsorption of surfactants on solids is affected by the intermolecular packing in the adsorbed layer besides the driving forces. The adsorption behavior of a double-chain surfactant on silica is studied here along with that of the single-chain one. Comparison of adsorption of these two surfactants is warranted since while the single-chain surfactants form spherical micelles, the double-chain ones form bilayered vesicles in solution. While the adsorption of the single-chain surfactant reaches the plateau in a wide concentration range, the adsorption of the double-chain one increases sharply in a concentration range 10−5 mol/L up to the plateau. The single chain is found to form 1.5 monolayers under saturation coverage suggesting adsorption with reverse orientation at high concentration. In contrast, the adsorption of the double-chain surfactant under saturation coverage is equivalent to a 0.9 monolayer. Fluorescence tests revealed the hydrophobicity change of the surface with increase in adsorption. However, the hydrophobicity tests show the solid surface to be hydrophilic in this range; the double-chain surfactant is proposed to form a partial bilayer. 相似文献
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Lad MD Birembaut F Matthew JM Frazier RA Green RJ 《Physical chemistry chemical physics : PCCP》2006,8(18):2179-2186
External reflection FTIR spectroscopy and surface pressure measurements were used to compare conformational changes in the adsorbed structures of three globular proteins at the air/water interface. Of the three proteins studied, lysozyme, bovine serum albumin and beta-lactoglobulin, lysozyme was unique in its behaviour. Lysozyme adsorption was slow, taking approximately 2.5 h to reach a surface pressure plateau (from a 0.07 mM solution), and led to significant structural change. The FTIR spectra revealed that lysozyme formed a highly networked adsorbed layer of unfolded protein with high antiparallel beta-sheet content and that these changes occurred rapidly (within 10 min). This non-native secondary structure is analogous to that of a 3D heat-set protein gel, suggesting that the adsorbed protein formed a highly networked interfacial layer. Albumin and beta-lactoglobulin adsorbed rapidly (reaching a plateau within 10 min) and with little change to their native secondary structure. 相似文献
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The possibility of reducing fibrinogen adsorption to solid surfaces by competitive adsorption of cellulose ethers (EHEC, HEC) was investigated. The surface concentration of fibrinogen adsorbed onto hydrophilic and hydrophobic (methylized) glass was measured with an enzyme-linked immunosorbent assay. The immunoassay was calibrated by ellipsometry, using the initial mass transport limitation of adsorption for calculations of the maximum amount of adsorbed protein.At a hydrophobic surface, the presence of cellulose polymers caused a decrease of the adsorption of fibrinogen. The hydrophobic EHEC (cloud point 35°C) was most efficient and abolished surface-adsorption of the protein.At a hydrophilic surface, positive cooperativity was seen between fibrinogen and cellulose polymers. The hydrophilic HEC (cloud point >100°C) gave the most prominent effect.The results indicate that the affinity between a water soluble polymer or protein and a solid surface is not the only factor determining surface adsorption. The finding that there may be both positive and negative cooperativity in the adsorption of polymers shows the importance of polymer compatibility in layers of adsorbed polymers. 相似文献
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W. Van der Vegt H. C. Van der Mei Dr. H. J. Busscher W. Norde 《Colloid and polymer science》1996,274(1):27-33
Interfacial tension changes during protein adsorption at both the solid-liquid and the liquid-vapor interface were measured simultaneously by ADSA-P from sessile droplets of protein solutions on fluoroethylenepropylene-Teflon. Four globular proteins of similar size, viz. lysozyme, ribonuclease, -lactalbumin and Ca2+-free -lactalbumin, and one larger protein, serum albumin, were adsorbed from phosphate solutions at varying pH values (pH 3-12). The kinetics of the interfacial tension changes were described using a model accounting for diffusion-controlled adsorption of protein molecules and conformational changes of already adsorbed molecules. The contribution of conformational changes to the equilibrium interfacial pressure was shown to be relatively small and constant with respect to pH when compared to the contribution of adsorption of the protein molecules. The model also yields the diffusion relaxation time and the rate constant for the conformational changes at the interface. Around the isoelectric point of a protein the calculated diffusion relaxation time was minimal, which is ascribed to the absence of an energy barrier to adsorption. Energy barriers to adsorption become larger at pH values away from the isoelectric point and can therefore become rate-limiting for the adsorption process. The rate constants for conformational changes at the liquid-vapor interface were maximal around the isoelectric point of a protein, suggesting a smaller structural stability of the adsorbed protein. At the solid-liquid interface the rate constants were smaller and independent of pH. indicating that conformational changes more readily occur at the liquid-vapor than at the solid-liquid interface. 相似文献