本文選題：親和膜　切入點(diǎn)：內(nèi)毒素　出處：《浙江大學(xué)》2012年碩士論文　論文類型：學(xué)位論文

【摘要】：內(nèi)毒素是革蘭氏陰性菌細(xì)胞壁上的脂多糖成分,進(jìn)入人體血液中后作用于免疫系統(tǒng),產(chǎn)生強(qiáng)烈的生物學(xué)效應(yīng),普遍被認(rèn)為與危重癥疾病膿毒血癥相關(guān)。親和吸附法是清除血液中的內(nèi)毒素最有效的方法之一,因此,開(kāi)展親和膜吸附內(nèi)毒素的研究對(duì)促進(jìn)膿毒血癥的治療具有非常重要的意義。 本文以常見(jiàn)的血液透析膜材料PSF為基質(zhì)膜材料,在保證膜材料主體性質(zhì)不變的前提下,針對(duì)PSF耐有機(jī)溶劑性能差的特點(diǎn),設(shè)計(jì)了一種可在常溫下進(jìn)行的PSF中空纖維膜表面改性方法：利用Friedel-Crafts反應(yīng)向聚砜膜表面引入活性基團(tuán)-CH2C1,以乙二胺為間隔臂,以戊二醛為活化劑,成功接枝配基L-Ser.膜上氨基酸密度可以通過(guò)控制第一步氯甲基化反應(yīng)程度來(lái)控制,最適宜的氯甲基化時(shí)間為60min,此時(shí)膜上配基密度為2.04μmol/cm2。ATR-FTIR和XPS表征結(jié)果顯示上述改性方法是有效的,靜態(tài)接觸角結(jié)果顯示PSF-Ser親和膜的親水性與PSF膜相比有了顯著提升。 接枝Ser配基后,膜在去離子水、磷酸緩沖液和BSA溶液中對(duì)內(nèi)毒素的特異性吸附均有所增強(qiáng),其吸附性能受到溶液環(huán)境中pH、離子強(qiáng)度、內(nèi)毒素濃度及蛋白質(zhì)濃度等因素的影響。在與血液生理環(huán)境相似的磷酸緩沖液(pH7.0,0.15M)中,PSF-Ser親和膜單位面積的內(nèi)毒素吸附量為1.656EU/cm2。與實(shí)驗(yàn)室前期制備的PVDF-Ser親和膜相比,PSF-Ser膜對(duì)內(nèi)毒素的吸附能力增強(qiáng)了,對(duì)BSA的吸附差別不大。 為了從分子層面討論配基與內(nèi)毒素作用機(jī)理,本文還建立了內(nèi)毒素的活性保守結(jié)構(gòu)——類脂A分子在CHARMM力場(chǎng)下的分子模型。其在水環(huán)境下的初態(tài)模擬構(gòu)象結(jié)果為穩(wěn)定的雙分子層結(jié)構(gòu),當(dāng)水質(zhì)量含量為40%時(shí),該雙分子層的厚度為4.65nm/4.98nm,其結(jié)構(gòu)與厚度均與文獻(xiàn)報(bào)道一致,證明所用力場(chǎng)參數(shù)可靠。此外,對(duì)類脂A分子排列成的雙分子層結(jié)構(gòu)進(jìn)行了原子級(jí)描述。 上述研究結(jié)果表明,制備得到的PSF-Ser中空纖維親和膜可特異性去除水溶液或蛋白質(zhì)溶液中的內(nèi)毒素,有望作為一種內(nèi)毒素吸附膜應(yīng)用在膿毒血癥病人的血液凈化治療過(guò)程中,同時(shí)建立起的類脂A分子力場(chǎng)模型可用于后續(xù)分子動(dòng)力學(xué)研究,為探討內(nèi)毒素與親和配基之間的作用機(jī)理奠定基礎(chǔ)。
[Abstract]:Endotoxin is a lipopolysaccharide component on the cell wall of Gram-negative bacteria. It acts on the immune system after entering the human blood and has a strong biological effect. Affinity adsorption is one of the most effective methods to remove endotoxin from blood. The study of adsorption of endotoxin by affinity membrane is of great significance in promoting the treatment of sepsis. In this paper, the common hemodialysis membrane material, PSF, is used as the matrix membrane material. On the premise of keeping the main properties of the membrane material unchanged, the characteristics of PSF's poor resistance to organic solvents are pointed out. A method of surface modification of PSF hollow fiber membrane at room temperature was designed. The active group -CH2C1 was introduced into the surface of polysulfone membrane by Friedel-Crafts reaction, with ethylenediamine as spacer and glutaraldehyde as activator. The densities of amino acids on the membrane can be controlled by controlling the degree of the first step chloromethylation reaction, and the optimum chloromethylation time is 60 minutes. The results of characterization of ligand density of 2.04 渭 mol/cm2.ATR-FTIR and XPS show that the above modification method is effective. The static contact angle showed that the hydrophilicity of PSF-Ser affinity membrane was significantly higher than that of PSF membrane. After grafting with Ser ligand, the specific adsorption of endotoxin in deionized water, phosphoric acid buffer and BSA solution was enhanced. Effects of endotoxin concentration and protein concentration on endotoxin adsorption of PSF-Ser affinity membrane in phosphate buffer (pH7.0 ~ 0.15M), which is similar to that of blood physiological environment. The endotoxin adsorption capacity per unit area of PSF-Ser affinity membrane is 1.656 EU. / cm ~ (2). Compared with the PVDF-Ser affinity membrane prepared in early laboratory, the PSF-Ser membrane is obtained. The ability to adsorb endotoxin increased, The adsorption of BSA has little difference. In order to discuss the mechanism of ligands acting on endotoxin at the molecular level, The molecular model of lipopolysaccharide A molecule under CHARMM force field is also established. The initial state simulation conformation of lipopolysaccharide A molecule under water environment is a stable bilayer structure, when the mass content of water is 40%, The thickness of the bimolecular layer is 4.65nm / 4.98nm.The structure and thickness of the bimolecular layer are consistent with those reported in the literature, which proves that the force field parameters used are reliable. In addition, the structure of bilimolecular layer arranged by lipoid A molecule is described at atomic level. These results indicate that the PSF-Ser hollow fiber affinity membrane can specifically remove endotoxin from aqueous solution or protein solution, which is expected to be used as a endotoxin adsorption membrane in blood purification treatment of sepsis patients. At the same time, the molecular force field model of lipids A can be used in the further study of molecular dynamics, which lays a foundation for the study of the interaction mechanism between endotoxin and affinity ligands.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2012
【分類號(hào)】：TQ028.8;R318.08

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 冷云飛;潘凱;原濤;曹兵;;聚砜超濾膜的表面化學(xué)改性[J];北京化工大學(xué)學(xué)報(bào)(自然科學(xué)版);2009年03期

2 甘宏宇,商振華,王俊德;親和膜色譜技術(shù)研究進(jìn)展[J];分析化學(xué);1999年01期

3 ;Preparation and Application of Polymyxin B Affinity Membrane Cartridge[J];Chinese Chemical Letters;1997年08期

4 商振華，周良模;膜親和色譜的現(xiàn)狀、發(fā)展和應(yīng)用[J];化學(xué)進(jìn)展;1995年01期

5 陳灝,陳歡林;膜色譜技術(shù)在生物大分子分離與純化中的應(yīng)用[J];膜科學(xué)與技術(shù);2001年05期

6 柴紅,錢驊,陳歡林;親和膜分離應(yīng)用研究進(jìn)展[J];膜科學(xué)與技術(shù);2003年04期

7 孫海翔;葛保勝;陳歡林;;免疫親和分離膜研究進(jìn)展[J];膜科學(xué)與技術(shù);2009年01期

8 陳穎;李雪梅;李曉明;;聚丙烯中空纖維膜拉伸性能測(cè)試方法試驗(yàn)研究[J];膜科學(xué)與技術(shù);2010年04期

9 徐X;黃曼;吳禮光;徐秋萍;張林;陳歡林;;絲氨酸配基PVDF親和膜脫除人血漿中內(nèi)毒素的研究[J];膜科學(xué)與技術(shù);2011年02期

10 魏桂林,商振華,于億年,劉學(xué)良,高志紅,潘明臣;新型親和膜色譜用于去除膽紅素的研究[J];色譜;2001年01期

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