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首页> 外文学位 >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.

机译：在大气压下通过等离子体进行的聚合：沉积物的表征及其生物技术应用。

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摘要

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.
机译：含氮（N）的聚合物表面在许多技术环境中都很有吸引力，例如在生物医学应用中。在这里，我们使用大气压介电势垒放电（DBD）设备，使用三种不同碳氢化合物前体（甲烷，乙烯和乙炔）在氮气中的混合物，沉积了新型的富N等离子体聚合物，命名为PP：N。改变各自的气体流量比，通常是千分之几。在为后续的细胞表面相互作用研究做准备时，本研究的第一部分侧重于这些材料的化学作图，并特别注意官能团的（半）定量分析。结合了成熟的和一些鲜为人知的分析技术，以提供这三种PP：N薄膜系列的最佳化学和结构表征。 X射线光电子能谱（XPS），近边缘X射线吸收精细结构（NEXAFS），傅立叶变换红外光谱（FTIR），接触角测角法（CAG）和元素分析（EA）。 XPS和EA均测量到高的“可调的”总氮含量（EA介于6％至25％之间，XPS介于10％至40％之间，无法检测到氢）。用4-三氟甲基苯甲醛（TFBA）进行化学衍生化可以测量伯胺浓度，这是最大的生物技术关注功能，被发现占总结合氮的5％至20％。通过结合上述补充方法，我们进一步能够确定PP：N膜结构中的完整化学式，不饱和度和其他主要化学官能团。在烃等离子体聚合物的文献中，其中一些特征被认为是没有先例的，例如绝对组成（包括氢）和不饱和度的测量。结果表明，除了胺之外，腈，异腈和亚胺是这些材料中主要的硝化官能团。在本工作的第二部分，我们研究了这些具有良好特征的表面与活细胞的相互作用。我们首先证明了三种不同类型的细胞在BOPP上均匀涂覆和微图案化的PP：N沉积物上的粘附，它们分别是生长板和关节软骨细胞以及U937单核细胞，后者在全部用于组织培养中使用的合成聚合物。为了深入了解细胞粘附机制，我们进行了一系列实验，在U937单核细胞上分别在PP：N和其他两个化学特性良好的富N薄膜家族中培养，后者通过RF等离子体和真空紫外（VUV）光聚合（“ PVP：N”膜）。首先表明存在诱导细胞粘附所必需的明确定义的（“临界”）表面化学条件。通过比较“临界”条件下广泛表征的膜化学性质，我们清楚地证明了伯胺在细胞粘附机制中的主导作用。在这项工作的最后一个方面，使用U937细胞进行了定量实时逆转录聚合酶链反应（实时RT-PCR）实验，该细胞已经粘附在PP：N和PVP：N材料上，直至24小时我们已经表明，U937单核细胞对PP：N和PVP：N表面的粘附诱导了细胞因子的瞬时表达，巨噬细胞活化的标志物以及PPARgamma和ICAM-1的持续表达，这与U937单核细胞的粘附和保留有关。关键词：生物材料；单核细胞介质阻挡放电（DBD）；沉积等离子体聚合； ESCA / XPS； NEXAFS； FTIR;伯胺；细胞粘附；基因表达。

著录项

  • 作者

    Girard-Lauriault, Pierre-Luc.;

  • 作者单位

    Ecole Polytechnique, Montreal (Canada).;

  • 授予单位 Ecole Polytechnique, Montreal (Canada).;
  • 学科 Engineering Biomedical.;Engineering Materials Science.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 250 p.
  • 总页数 250
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 生物医学工程;工程材料学;
  • 关键词

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