Polymeric nanoparticles synthesized via miniemulsion process as templates for biomimetic mineralization [Elektronische Ressource] / vorgelegt von Anitha Ethirajan

Anitha

Informations

• Publié par: universitat_ulm
• Publié le: 01 janvier 2008
• Nombre de lectures: 27
• Poids de l'ouvrage: 25 Mo

Extrait

Polymeric Nanoparticles Synthesized via
Miniemulsion Process as Templates for
Biomimetic Mineralization




Dissertation
Zur Erlangung des Doktorgrades Dr. rer. nat.
der Fakultät für Naturwissenschaften
der Universität Ulm
vorgelegt von

Anitha Ethirajan
aus Chennai / Indien
2008

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Dissertation der Universität Ulm
Amtierender Dekan: Prof. Dr. Klaus-Dieter Spindler
1. Gutachterin: Prof. Dr. Katharina Landfester
2. Gutachterin: Prof. Dr. Ute Kaiser

Tag der Promotion: 20. 10. 2008
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Dedicated to my family

iii ivTable of Contents
1 Introduction.........................................................................................................................1
2 Theoretical section ..............................................................................................................4
2.1 Heterogeneous system...........................................................................4
2.1.1 Miniemulsions....................................................................................................................6
2.1.2 Stability of miniemulsions .................................................................................................7
2.1.3 Inverse miniemulsion.........................................................................................................9
2.1.4 Artificial latex ..................................................................................................................10
2.2 Biomineralization and biomimetics .............................................................................12
2.2.1 Crystallization in relevance to biomineralization and biomimetic mineralization...........13
2.2.1.1 Nucleation ................................................................................................................14
2.2.1.2 Crystal growth..........................................................................................................17
2.2.1.3 Thermodynamic and kinetic driving forces..............................................................17
2.2.2 Strategies for biomimetic mineralization - Applying concepts in biomineralization.......19
2.2.2.1 Templating and confining the reaction environment................................................20
2.2.2.2 Non classical crystallization.....................................................................................22
2.2.2.3 Mesocrystals.............................................................................................................23
2.2.3 Biominerals ......................................................................................................................24
2.2.3.1 Bone .........................................................................................................................25
2.2.3.2 Teeth.........................................................................................................................26
2.2.4 Hydroxyapatite mineralization.........................................................................................27
2.2.5 Polymeric nanoparticles as templates ..............................................................................29
2.2.5.1 Gelatin nanoparticles................................................................................................30
2.2.5.2 Synthetic polymeric templates .................................................................................32
3 Analytical techniques........................................................................................................35
3.1 Electron microscopy............................................................................35
3.1.1 Scanning electron microscopy (SEM) .............................................................................36
3.1.2 Transmission electron microscopy (TEM).......................................................................36
3.2 X-ray diffraction ..........................................................................................................37
3.3 Dynamic light scattering..............................................................................................39
4 Experimental section........................................................41
v4.1 Synthesis of gelatin nanoparticles................................................................................41
4.2 Biomimetic mineralization of hydroxyapatite using gelatin nanoparticles .................43
4.3 Functionalized polymeric nanoparticles for mineralization ........................................44
4.4 Biodegradable polymeric nanoparticles for mineralization.................46
4.5 Encapsulation of hydroxyapatite..................................................................................47
5 Results and discussions.....................................................................................................49
5.1 Gelatin nanoparticles...........................................................................49
5.1.1 Variation of gelatin type and crosslinker concentration...................................................49
5.1.2 Thermal cycle and swelling .............................................................................................54
5.1.3 Optimization of crosslinking efficiency...........................................................................57
5.1.4 UV-vis spectrometer studies ............................................................................................60
5.1.5 Electron microscopy studies ............................................................................................62
5.2 Biomimetic mineralization of hydroxyapatite using gelatin nanoparticles .................65
5.2.1 Loading of gelatin nanoparticles......................................................................................65
5.2.2 TEM characterization.......................................................................................................67
5.2.3 XRD characterization.......................................................................................................72
5.2.4 IR spectroscopic studies...................................................................................................74
5.2.5 External precipitation and calcium uptake of gelatin nanoparticles.................................75
5.2.6 Adjoining nanoparticles ...................................................................................................77
5.2.7 Time-dependent morphology and stability characterization............................................78
5.2.8 Variation of the surfactant concentration.........................................................................80
5.2.9 Addition of amino acids...................................................................................................81
5.2.10 Adpoly(amino acids) .........................................................................................83
5.2.11 Gelatin nanoparticles as versatile template ......................................................................86
5.3 Functionalized polymeric nanoparticles as templates..................................................90
5.3.1 Polymerization using ionic and non-ionic surfactants .....................................................90
5.3.2 Surface group titration .....................................................................................................93
5.3.3 Formation of hydroxyapatite nanocrystals.......................................................................94
5.4 Biodegradable nanoparticles as templates .................................................................106
5.4.1 Synthesis and characterization of polymer nanoparticles ..............................................107
5.4.2 Calcium phosphate mineralization.................................................................................110
5.4.3 Encapsulation of hydroxyapatite....................................................................................119
vi6 Conclusions ......................................................................................................................124
7 Zusammenfassung...................................................................................128
8 Appendix ..................................................................................................132
8.1 Characterization methods...................................................................132
8.2 Abbreviations.............................................................................................................137
9 References ................................................................................................139
Acknowledgements..........................................................................................................148
Curriculum Vitae ....................................................................................151
List of Publications..........................................................................................................152
Declaration................................................................................................