Degradable phosphate glasses and composite materials for biomedical applications [Elektronische Ressource] / von Delia S. Brauer

Degradable Phosphate Glasses and Composite
Materials for Biomedical Applications









Dissertation
zur Erlangung des akademischen Grades doctor rerum naturalium
(Dr. rer. nat.)

















vorgelegt dem Rat der Chemisch-Geowissenschaftlichen Fakultät der
Friedrich-Schiller-Universität Jena

von Dipl.-Chem. Delia S. Brauer
geboren am 28.07.1976 in Berlin-Neukölln

































Gutachter:
1. Prof. Dr. Christian Rüssel
2. Prof. Dr. Dörte Stachel
Tag der öffentlichen Verteidigung: 22. Juni 2005
Contents
ZUSAMMENFASSUNG..................................................................................... 1
1 INTRODUCTION AND OBJECTIVE .......................................................... 8
2 THEORY AND LITERATURE REVIEW.................................................... 12
2.1 Bone and hard tissue ................................................................................................................. 12
2.2 Implant materials ...................................................................................................................... 13
2.2.1 Internal fracture fixation ......................................................................................................... 14
2.2.2 Degradable implants ............................................................................................................... 15
2.3 Glasses and glass properties ..................................................................................................... 17
2.3.1 Glass structure ........................................................................................................................ 17
2.3.2 Solubility and degradation.19
2.3.3 Phosphate glass fibers............................................................................................................. 23
2.4 Degradable polymers..... 25
2.4.1 Composite materials ............................................................................................................... 27
2.5 Cell experiments ........................................................................................................................ 30
2.5.1 Cell compatibility of glasses...................................................................................................31
3 EXPERIMENTAL PROCEDURE .............................................................. 35
3.1 Glasses ........................................................................................................................................ 35
3.1.1 Glass synthesis........................................................................................................................ 35
3.1.2 Chemical analysis ................................................................................................................... 36
3.1.3 Glass structure........ 36
3.1.4 Density, crystallization and viscosity ..................................................................................... 37
3.1.5 Porous glass cubes .................................................................................................................. 37
3.1.6 Glass fibers ............................................................................................................................. 38 Contents II
3.2 Composites ................................................................................................................................. 38
3.2.1 Applied organic polymer ........................................................................................................ 39
3.2.2 Fabrication of composites.......................................................................................................40
3.2.3 Mechanical strength and porosity ........................................................................................... 41
3.3 Solubility experiments............................................................................................................... 42
3.3.1 pH measurements.................................................................................................................... 42
3.3.2 Solubility in deionized water .................................................................................................. 42
3.3.3 Degradation in simulated body fluid....................................................................................... 42
3.4 Cell experiments ........................................................................................................................ 43
3.4.1 Cell culture ............................................................................................................................. 43
3.4.2 SEM analysis and HE staining................................................................................................ 43
3.4.3 Proliferation experiments........................................................................................................ 44
3.4.4 Viability assay ........................................................................................................................ 45
3.5 Statistical evaluation ................................................................................................................. 46
3.5.1 Analysis of variance (ANOVA).............................................................................................. 46
3.5.2 Multiple linear regression (MLR)........................................................................................... 46
3.5.3 Neural networks (NN) ............................................................................................................47
3.5.4 Modeling of solubility... 47
4 RESULTS ................................................................................................. 49
4.1 Polyphosphate glasses ............................................................................................................... 49
4.1.1 Glass structure ........................................................................................................................ 49
4.1.2 Density, crystallization and viscosity ..................................................................................... 52
4.1.3 Solubility ................................................................................................................................ 54
4.2 Pyrophosphate glasses..... 60
4.2.1 Density, crystallization and viscosity 61
4.2.2 Solubility........... 65
4.2.3 Cell experiments ..................................................................................................................... 69
4.3 Porous glasses and composites.................................................................................................. 73
4.3.1 Porosity................................................................................................................................... 73
4.3.2 Compressive strength.............................................................................................................. 74
4.3.3 Adhesive shear strength.......................................................................................................... 75
4.3.4 Solubility ................................................................................................................................ 76
4.3.5 Cell experiments...... 78 Contents III
4.4 Glass fibers and composites...................................................................................................... 81
5 DISCUSSION............................................................................................ 85
5.1 Polyphosphate glasses ............................................................................................................... 85
5.2 Pyrophosphate glasses..... 87
5.3 Modeling of solubility................................................................................................................ 92
5.4 Composites ................................................................................................................................. 94
6 CONCLUSION.......................................................................................... 98
BIBLIOGRAPHY............................................................................................ 103
APPENDIX..................................................................................................... 118
A Synthetic glass composition ......................................................................................................... 118
B Analytic glass composition...... 120
C Solubility results ........................................................................................................................... 121
D Glass data...................................................................................................................................... 124
FIGURES ....................................................................................................... 127
TABLES..........................