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Publié par | Thesee |
Nombre de lectures | 40 |
Langue | English |
Poids de l'ouvrage | 4 Mo |
Extrait
THESE en cotutelle
entre
L’UNIVERSITE DU MAINE
&
JOŽEF STEFAN INTERNATIONAL POSTGRADUATE SCHOOL
En vue d’obtenir le titre de
DOCTEUR
Spécialité : Chimie et Physico-Chimie des polymères
lle
par M Tjaša VRLINIČ
« Development of new anti-bioadhesive surfaces for specific
neurodegenerative agents »
Thèse soutenue le 13 Mai 2011, devant le jury composé de :
K. ANSELME Docteur IS2M, Mulhouse Rapporteur
U. CVELBAR Professeur IJS, Ljubljana Rapporteur
R. BRIANDET Docteur INRA, Massy Examinateur
B. EL MOUALIJ Docteur ULG, Liège Examinateur
G. LEGEAY Docteur CTTM, Le Mans Examinateur
D. DEBARNOT Maître de conférences PCI, Le Mans Examinateur
M. MOZETIC Professeur IJS, Ljubljana Directeur
F. PONCIN- EPAILLARD Directrice de recherche PCI, Le Mans Directeur II
Index III
Index
1 Introduction................................................................................................................... 1
1.1 Design of novel biomaterials...................................................................................... 4
1.1.1 What are biomaterials? .......................................................................................... 4
1.1.2 Fundamental interactions between surfaces and biomolecules ............................. 6
1.1.3 Techniques for modification of biomaterials ........................................................ 8
1.2 Biomaterial elaboration through one step plasma functionalization........................ 10
1.2.1 Plasma state ......................................................................................................... 11
1.2.1.1 Non-equilibrium “cold” plasma.................................................................... 14
1.2.2 Plasma-surface interactions................................................................................. 14
1.2.3 Applications of low pressure non-equilibrium plasmas ...................................... 16
1.2.3.1 Development of (super) hydrophobic surfaces............................................. 17
1.2.3.2 Development of (super) hydrophilic surfaces............................................... 20
1.3 Biomaterial elaboration through two-step treatment: Surface activation and
polymer grafting....................................................................................................... 22
1.3.1 Grafting of polymer brushes................................................................................ 22
1.3.1.1 “Grafting to” and “grafting from” methods.................................................. 22
1.3.1.2 Homopolymer brushes.................................................................................. 24
1.3.1.3 Mixed polymer and copolymer brushes........................................................ 27
1.3.2 Grafting of surfactants......................................................................................... 28
1.3.3 Grafting of particular thermo-sensitive polymer: PNIPAM................................ 31
1.4 Proteins and surfaces................................................................................................ 36
1.4.1 Protein-surface interactions................................................................................. 36
1.4.1.1 Protein structure and properties .................................................................... 39
1.4.1.2 Influence of surface hydrophobicity and hydrophilicity on adsorption........ 41
1.4.1.3 Influence of charge on adsorption ................................................................ 43
1.4.1.4 Influence of surface topography and roughness on adsorption .................... 44
1.4.1.5 Protein adsorption from multi-component solutions .................................... 46
1.4.2 Protein resistant surfaces ..................................................................................... 47
1.4.3 Physicochemical properties of specific proteins: prion protein, Tau and α-
synuclein.............................................................................................................. 49
1.5 Summary and outlook .............................................................................................. 51
2 Experimental part....................................................................................................... 53
2.1 Functionalization of supports................................................................................... 55
2.1.1 Plasma treatment ................................................................................................. 55
2.1.2 Preparation of immersion solutions..................................................................... 56
2.1.3 Surface grafting ................................................................................................... 57
2.2 Characterisation of plasma by optical emission spectroscopy (OES)...................... 59
2.3 Surface characterisation ........................................................................................... 60
2.3.1 Surface grafting ................................................................................................... 60 Index IV
2.3.2 X-ray photoelectron spectroscopy (XPS)............................................................ 61
2.3.3 Zeta potential measurements ............................................................................... 62
2.3.4 Atomic force spectroscopy (AFM)...................................................................... 63
2.3.5 Confocal microscopy........................................................................................... 63
2.4 Biological validation of Eppendorf tubes by ELISA tests ....................................... 64
2.4.1 ELISA protocols for detection of different neurodegenerative agents................ 65
2.4.1.1 Direct and “sandwich” ELISA protocol for detection of PrPrec ............. 65 hum
2.4.1.2 “Sandwich” ELISA protocol for detection of PrPc from CSF ..................... 67
2.4.1.3 “Sandwich” ELISA protocol for detection of Tau .................................... 67 rec
2.4.1.4 “Sandwich” ELISA protocol for detection of TauPHF from CSF ............... 68
2.4.1.5 “Sandwich” ELISA protocol for detection of Tau from CSF ................... 68 tot
2.4.1.6 “Sandwich” ELISA protocol for detection of Aβ-42 from CSF................... 69
2.4.1.7 “Sandwich” ELISA protocol for detection of α-syn..................................... 69
3 Results and discussion: Surface modification and analyses.................................... 71
3.1 Hydrophobic modification of polymeric surfaces through one-step CF 4
plasma treatment ...................................................................................................... 71
3.1.1 Characterization of the plasma phase .................................................................. 72
3.1.2 Characterization of modified surfaces; determination of the hydrophobic
properties ............................................................................................................. 76
3.1.2.1 Influence of discharge power on the wettability of modified surfaces......... 76
3.1.2.2 Influence of pressure on the wettability of modified surfaces...................... 77
3.1.2.3 Influence of treatment time on the wettability of modified surfaces............ 78
3.1.2.4 Ageing effects on the plasma-fluorinated surfaces....................................... 80
3.1.3 Characterization of the chemical composition of modified surfaces .................. 81
3.1.3.1 Influence of treatment time on the surface chemistry................................... 82
3.1.3.2 Influence of discharge power on the surface chemistry................................ 83
3.1.3.3 Influence of pressure on the surface chemistry............................................. 84
3.1.4 Characterization of the surface charge of plasma-fluorinated surfaces............... 89
3.1.5 Characterization of the surface morphology ....................................................... 91
3.2 Hydrophilic modification of polymers through two-step treatment: Plasma
activation and polymer grafting ............................................................................... 93
3.2.1 Fist step: Activation of substrates by helium plasma .......................................... 93
3.2.1.1 Helium plasma characterisation.................................................................... 93
3.2.1.2 Characterisation of the activated surface, determination of hydrophilic
properties ...................................................................................................... 95
3.2.1.2.1 Influence of pressure on the wettability of modified surfaces ................. 95
3.2.1.2.2 Influence of discharge power on the wettability of modified
surfaces..................................................................................................... 96
3.2.1.2.3 Influence of treatment time on the wettability of modified surfaces ....... 98
3.2.1.2.4 Ageing effects on the plasma-activated surfaces ..................................... 98
3.2.1.3 Characterisation of the activated surface, determination of hydrophilic
properties ........................................