Fibrinogen Adsorption on Biomaterials as Characterized by Transmission FTIR Spectroscopy

ＩｎｔｒｏｄｕｃｔｉｏｎＨｅｍｏｃｏｍｐａｔｉｂｉｌｉｔｙｏｆｂｉｏｍａｔｅｒｉａｌｓｃａｎｂｅｉｎｖｅｓｔｉｇａｔｅｄｆｒｏｍｄｉｆｅｒｅｎｔｐｏｉｎｔｓｏｆｖｉｅｗ．Ｔｈｅａｄｓｏｒｐｔｉｏｎｏｆｐｌａｓｍａｐｒｏｔｅｉｎｓｏｎｔｏｂｉｏｍａｔｅ...     

pH Dependence of Chlorophyll States, Protein Structures and Function of the PSII Membranes

IntroductionPhotosystem II ( PSII) is a pigment- proteincomplex in the thylakoid membrane. Its reactioncenter( PSII- RC) ,which is composed of D1 andD2 proteins,generates the highly positive oxidantrequired for the oxidation of water by light- drivencharge separation. Water oxidation occurs at theMn4cluster positioned atthe center of the oxygen-evolving complex on the lumenal surface of PSII.In green plants,the highly reactive Mn4cluster isshielded by a number of extrinsic proteins( 33…     

Behavior of MC3T3-E1 Osteoblast Cultured on Chitosan Modified with Polyvinylpyrrolidone

The physical and chemical properties of four kinds of modified chitosan materials made by blending chitosan with polyvinylpyrrolidone （PVP） were investigated. All four of these modified chitosan materials were hydrophilic with water contact angles ranging from 59°to 69°. Fourier transform-infrared spectra of the modified materials showed a new band at 1288 cm^-1, implying formation of a surface physical interpenetrating network structure. Enzyme linked immunosorbent assay results indicated that much less fibronectin was adsorbed on the modified materials than on only chitosan. The viability of MC3T3-E1 osteoblasts cultured on the materials was assessed by 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl- 2H-tetrazolium bromide assay. The results show that adding PVP10000 into the chitosan promotes adhesion of MC3T3-E1 osteoblasts on the modified materials, but has no effect on cell growth and proliferation; while adding PVP40000 reduces cell adhesion, growth, and proliferation. The results suggest that the increased hydrophilicity of the material surface does not always improve its biocompatibility, which will influence the selection and design of biomaterials.     

正电和中性磷脂对纤维蛋白原的吸附比较

常用纤维蛋白原的吸附特性来比较和研究材料的血液相容性。将自行合成的正电磷脂ＤＰＰＥＬ膜铺展在金膜表面,测量了膜表面的接触角及对纤维蛋白原的动态吸附特性,并与裸金膜、中性磷脂ＤＳＰＣ膜进行了比较。结果表明：ＤＳＰＣ膜、ＤＰＰＥＬ膜和裸金膜的接触角分别为３８°０５′,５７°２０′和７８°２４′。在相同的纤维蛋白原溶液浓度条件下,裸金膜表面吸附纤维蛋白原的速率最快,饱和吸附量最大（３．５０ｎｇ／ｍｍ２）;磷脂ＤＳＰＣ膜表面吸附纤维蛋白原的速度最低,饱和吸附量也最小（１．００ｎｇ／ｍｍ２）;磷脂ＤＰＰＥＬ膜吸附速率也较快,饱和吸附量为１．７５ｎｇ／ｍｍ２。表明纤维蛋白原在界面上的吸附特性与材料表面疏水性质和带电特性相关。ＰＣ头良好的亲水性和电中性,是其能改善生物医用材料血液相容性的重要原因。     

Endothelial Cell Culture on Different Phospholipid Surfaces *

ＩｎｔｒｏｄｕｃｔｉｏｎＢｉｏｍａｔｅｒｉａｌｓａｒｅａｌｗａｙｓｕｓｅｄｉｎａｎｅｎｖｉｒｏｎｍｅｎｔａｄｊａｃｅｎｔｔｏｌｉｖｉｎｇｔｉｓｓｕｅｓａｎｄｂｌｏｏｄ．Ｃｅｌｕｌａｒｉｎｔｅｒａｃｔｉｏｎｓｗｉｔｈｉｍｐｌａｎｔｓａｒｅｏｆｐｒｉｍａ...     

Fibrinogen Structural Changes Caused by Glass Surface Adsorption Detected by Solid Surface Fluorescence Spectroscopy

ＦｉｂｒｉｎｏｇｅｎＳｔｒｕｃｔｕｒａｌＣｈａｎｇｅｓＣａｕｓｅｄｂｙＧｌａｓｓＳｕｒｆａｃｅＡｄｓｏｒｐｔｉｏｎＤｅｔｅｃｔｅｄｂｙＳｏｌｉｄＳｕｒｆａｃｅＦｌｕｏｒｅｓｃｅｎｃｅＳｐｅｃｔｒｏｓｃｏｐｙ＊ＧｏｎｇＹａｎｄａｏ（公衍道），ＤｉｎｇＸ...     

Different Modes of the Effect of 1,2-Propanediol and Azone on Stratum Corneum Lipids

IntroductionThe use of chemical enhancers is an effectivemethod for promoting drug diffusion andpenetration into and through the skin. Thefunction of different enhancers is based upondifferent mechanisms.For some enhancers,thefunction may be dependent on severalmechanisms[1] .However,the connection betweenthe characteristics of the enhancer and themechanism and the principles for enhancerscreening are not very clear.The stratum corneum(SC) is the main barrierof the skin. Studying the interac…     

Heat Denaturation of Protein Structures and Chlorophyll States in PSII Membranes

IntroductionPhotosystem II (PSII) is a large supramolecularpigment-protein complex found in the thylakoidmembranes of green plants,algae andcyanobacteria.Its main role is to drive light-induced electron transfer from water toplastoquinone with a concomitant production ofmolecular oxygen.PSII membranes consist of anouter antenna portion of light-harvestingchlorophyll (Chl) a/b binding complexes (LHCII)and a core fraction.The core fraction is composedof an inner antenna of membrane-bound …     

Light and Heat Induced Denaturation of Photosystem Ⅱ Core Antenna Complex CP47

ＩｎｔｒｏｄｕｃｔｉｏｎＰｈｏｔｏｓｙｓｔｅｍⅡ (ＰＳⅡ )ｏｆｈｉｇｈｅｒｐｌａｎｔｓｉｓａｍｅｍｂｒａｎｅｐｒｏｔｅｉｎｃｏｍｐｌｅｘｌｏｃａｔｅｄｉｎｔｈｅｔｈｙｌａｋｏｉｄｍｅｍｂｒａｎｅ ,ｗｈｉｃｈｃｏｎｓｉｓｔｓｏｆｍｏｒｅｔｈａｎ 2 0ｐｒｏｔｅｉｎｓ[1] .Ｉｔｕｓｅｓｓｏｌａｒｅｎｅｒｇｙｔｏｃａｒｒｙｏｕｔｔｈｅｐｒｉｍａｒｙ ｐｒｏｃｅｓｓｅｓｏｆ ｐｈｏｔｏｓｙｎｔｈｅｓｉｓ :ｃｈａｒｇｅｓｅｐａｒａｔｉｏｎ ,ｑｕｉｎｏｎｅｒｅｄｕｃｔｉｏｎ ,ａｎｄｗａｔｅｒｏｘｉｄａｔｉｏｎｔ…     

人纤维蛋白原与聚四氟乙烯表面间相互作用的研究

在生物医学材料的研究和应用中,亟待解决的一个重要问题是这些材料的血液相容性问题.一般认为生物医学材料表面吸附了纤维蛋白原(Human fibrinogen,Fg),γ-球蛋白等糖蛋白后,就会与血小板形成复合体而粘附于材料表面,加速内源性凝血,促使溶胶状态的纤维蛋白原转变成为凝胶状态的纤维蛋白,从而造成凝血.尽管人们对于血浆蛋白与各种材料表面的相互作用已进行了大量的研究,然而血浆蛋白在材料表面的吸附机理至今尚不清楚.为了搞清楚材料表面凝血的机理,首先需要从界面反应的角度研究吸附在材料表面的血浆蛋白分子的结构和功能上发生的变化.Fg是理解凝血、抗凝、血栓形成与溶栓机制的核心,本文将Fg吸附在平均粒径约100μm不透明的聚四氟乙烯(Poly tetrafluro ethylene,PTFE)微粒表面,用圆二色(Circular dichroism,CD)光谱方法研究它们间的相互作用,为从分子水平理解PTFE表面的血液相容性提供了一定的依据.