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首頁> 外文學(xué)位 >Polymerisation par plasma a pression atmospherique: Caracterisation des depots et leurs applications en biotechnologies.
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Polymerisation par plasma a pression atmospherique: Caracterisation des depots et leurs applications en biotechnologies.

機譯：在大氣壓下通過等離子體進行的聚合：沉積物的表征及其生物技術(shù)應(yīng)用。

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Nitrogen (N)-containing polymer surfaces are attractive in numerous technological contexts, for example in biomedical applications. Here, we have used an atmospheric-pressure dielectric barrier discharge (DBD) apparatus to deposit novel families of N-rich plasma polymers, designated PP:N, using mixtures of three different hydrocarbon precursors (methane, ethylene, and acetylene) in nitrogen at varying respective gas flow ratios, typically parts per thousand. In preparation for subsequent cell-surface interaction studies, the first part of this research focuses on the chemical mapping of those materials, with specific attention to (semi)- quantitative analyses of functional groups. Well-established and some lesser-known analytical techniques have been combined to provide the best possible chemical and structural characterisations of these three families of PP:N thin films; namely, X-ray photoelectron spectroscopy (XPS), Near-edge X-ray absorption fine structure (NEXAFS), Fourier transform infrared spectroscopy (FTIR), contact angle goniometry (CAG), and elemental analysis (EA). High, "tunable" total nitrogen content was measured by both XPS and EA (between 6% and 25% by EA, or between 10% and 40% by XPS, which cannot detect hydrogen). Chemical derivatisation with 4-trifluoromethylbenzaldehyde (TFBA) enabled measurements of primary amine concentrations, the functionality of greatest bio-technological interest, which were found to account for 5 % to 20 % of the total bound nitrogen. By combining the above-mentioned complementary methods, we were further able to determine the complete chemical formulae, the degrees of unsaturation, and other major chemical functionalities in PP:N film structures. Several of these features are believed to be without precedents in the literature on hydrocarbon plasma polymers, for example measurements of absolute compositions (including hydrogen), and of unsaturation. It was shown that besides amines, nitriles, isonitriles and imines are the main nitrogenated functional groups in those materials.;In a second part of this work, we have studied the interraction of these well-characterised surfaces with living cells. We have first demonstrated the adhesion, on both uniformly coated and micro-patterned PP:N deposits on BOPP, of three different cell types, namely, growth plate and articular chondrocytes, as well as U937 monocytes, the latter of which do not adhere at all to synthetic polymers used in tissue culture. In an effort to gain insight into cell adhesion mechanisms, we conducted a series of experiments where we cultured U937 monocytes on PP:N, as well as on two other families of chemically well-characterised N-rich thin films, the latter deposited by low pressure RF plasma and by vacuum ultra-violet (VUV) photo-polymerisation ("PVP:N" films). It was first shown that there exist sharply- defined ("critical") surface-chemical conditions that are necessary to induce cell adhesion. By comparing the extensively-characterised film chemistries at the " critical " conditions, we have clearly demonstrated the dominant role of primary amines in the cell adhesion mechanism. In the final aspect of this work, quantitative real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) experiments were conducted using U937 cells that had been made to adhere on PP:N and PVP:N materials for up to 24h. We have shown that the adhesion of U937 monocytes to PP:N and PVP:N surfaces induced a transient expression of cytokines, markers of macrophage activation, as well as a sustained expression of PPARgamma and ICAM-I, implicated in the adhesion and retention of monocytes.;Keywords: biomaterials; dielectric barrier discharges (DBD); deposition; plasma polymerisation; ESCA/XPS; NEXAFS; FTIR; primary amines; cell adhesion; gene expression.
機譯：含氮（N）的聚合物表面在許多技術(shù)環(huán)境中都很有吸引力，例如在生物醫(yī)學(xué)應(yīng)用中。在這里，我們使用大氣壓介電勢壘放電（DBD）設(shè)備，使用三種不同碳?xì)浠衔锴绑w（甲烷，乙烯和乙炔）在氮氣中的混合物，沉積了新型的富N等離子體聚合物，命名為PP：N。改變各自的氣體流量比，通常是千分之幾。在為后續(xù)的細(xì)胞表面相互作用研究做準(zhǔn)備時，本研究的第一部分側(cè)重于這些材料的化學(xué)作圖，并特別注意官能團的（半）定量分析。結(jié)合了成熟的和一些鮮為人知的分析技術(shù)，以提供這三種PP：N薄膜系列的最佳化學(xué)和結(jié)構(gòu)表征。 X射線光電子能譜（XPS），近邊緣X射線吸收精細(xì)結(jié)構(gòu)（NEXAFS），傅立葉變換紅外光譜（FTIR），接觸角測角法（CAG）和元素分析（EA）。 XPS和EA均測量到高的“可調(diào)的”總氮含量（EA介于6％至25％之間，XPS介于10％至40％之間，無法檢測到氫）。用4-三氟甲基苯甲醛（TFBA）進行化學(xué)衍生化可以測量伯胺濃度，這是最大的生物技術(shù)關(guān)注功能，被發(fā)現(xiàn)占總結(jié)合氮的5％至20％。通過結(jié)合上述補充方法，我們進一步能夠確定PP：N膜結(jié)構(gòu)中的完整化學(xué)式，不飽和度和其他主要化學(xué)官能團。在烴等離子體聚合物的文獻中，其中一些特征被認(rèn)為是沒有先例的，例如絕對組成（包括氫）和不飽和度的測量。結(jié)果表明，除了胺之外，腈，異腈和亞胺是這些材料中主要的硝化官能團。在本工作的第二部分，我們研究了這些具有良好特征的表面與活細(xì)胞的相互作用。我們首先證明了三種不同類型的細(xì)胞在BOPP上均勻涂覆和微圖案化的PP：N沉積物上的粘附，它們分別是生長板和關(guān)節(jié)軟骨細(xì)胞以及U937單核細(xì)胞，后者在全部用于組織培養(yǎng)中使用的合成聚合物。為了深入了解細(xì)胞粘附機制，我們進行了一系列實驗，在U937單核細(xì)胞上分別在PP：N和其他兩個化學(xué)特性良好的富N薄膜家族中培養(yǎng)，后者通過RF等離子體和真空紫外（VUV）光聚合（“ PVP：N”膜）。首先表明存在誘導(dǎo)細(xì)胞粘附所必需的明確定義的（“臨界”）表面化學(xué)條件。通過比較“臨界”條件下廣泛表征的膜化學(xué)性質(zhì)，我們清楚地證明了伯胺在細(xì)胞粘附機制中的主導(dǎo)作用。在這項工作的最后一個方面，使用U937細(xì)胞進行了定量實時逆轉(zhuǎn)錄聚合酶鏈反應(yīng)（實時RT-PCR）實驗，該細(xì)胞已經(jīng)粘附在PP：N和PVP：N材料上，直至24小時我們已經(jīng)表明，U937單核細(xì)胞對PP：N和PVP：N表面的粘附誘導(dǎo)了細(xì)胞因子的瞬時表達(dá)，巨噬細(xì)胞活化的標(biāo)志物以及PPARgamma和ICAM-1的持續(xù)表達(dá)，這與U937單核細(xì)胞的粘附和保留有關(guān)。關(guān)鍵詞：生物材料；單核細(xì)胞介質(zhì)阻擋放電（DBD）；沉積等離子體聚合； ESCA / XPS； NEXAFS； FTIR;伯胺；細(xì)胞粘附；基因表達(dá)。

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  • 作者單位

    Ecole Polytechnique, Montreal (Canada).;

  • 授予單位 Ecole Polytechnique, Montreal (Canada).;
  • 學(xué)科 Engineering Biomedical.;Engineering Materials Science.
  • 學(xué)位 Ph.D.
  • 年度 2009
  • 頁碼 250 p.
  • 總頁數(shù) 250
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類 生物醫(yī)學(xué)工程;工程材料學(xué);
  • 關(guān)鍵詞

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