Thin Calcium Phosphate Coatings for Medical Implants (eBook)

Preface 5
Contents 6
Contributors 8
List of Abbreviations 12
Introduction 16
1.1 Plasma-Sprayed Calcium Phosphate Coatings 17
1.2 Clinical Perspective of CaP-Coated Implants 18
1.3 Clinical Concerns About Plasma-Spray CaP Coatings 19
1.4 Future Perspectives of CaP-Coated Implants 21
References 21
Physicochemistry of Apatite and Its Related Calcium Phosphates 24
2.1 Biomaterials for Bone and Teeth Replacement 24
2.2 Properties and Structure of Calcium Phosphate Ceramics 29
2.3 Dissolution and Formation of Calcium Phosphate Crystals 33
2.4 Biological Studies with Calcium Phosphate Bioceramics 35
References 38
Characterization of Thin Calcium Phosphate Coating 40
3.1 Introduction 40
3.2 Infrared Spectroscopy 41
3.2.1 Application Example 42
3.3 Raman Spectroscopy 43
3.3.1 Application Example 44
3.4 X-ray Photoelectron Spectroscopy 46
3.4.1 Qualitatitive and Quantitative XPS 47
3.4.2 Chemical Shifts 47
3.4.3 Application Example 48
3.4.4 Depth Information 49
3.5 Auger Electron Spectroscopy 50
3.6 X-ray Diffraction 50
3.6.1 Application Example 51
3.7 Electron Microscopy Techniques 53
3.7.1 Scanning Electron Microscopy 54
3.7.2 Energy Dispersive X-ray Spectroscopy 56
3.7.3 Transmission Electron Microscopy 56
3.8 Ion Beam Techniques 58
3.8.1 Rutherford Back-Scattering Spectrometry 58
3.8.2 Elastic Recoil Detection 62
3.8.3 Low Energy Ion Scattering 64
3.8.4 Proton-Induced X-ray Emission 64
3.8.5 Secondary Ion Mass Spectrometry 64
3.9 Nuclear Magnetic Resonance 65
3.9.1 Relevant NMR Basics 65
3.9.2 Application Examples 69
3.9.2.1 Characterization of Crystalline CaPs 69
3.9.2.2 NMR of Plasma-Sprayed Coatings 70
3.9.2.3 NMR Studies of Nano-crystalline HA and of Bone 71
3.9.3 Outlook 72
3.10 Mechanical Testing of Thin CaP Coatings 73
3.10.1 Adhesion Testing 73
3.10.1.1 Tensile Test 73
3.10.1.2 Scratch Test 74
3.10.2 Nanoindentation 76
References 78
In Vitro and In Vivo Evaluation of Thin Calcium Phosphate Coatings 82
4.1 Introduction 82
4.2 Development of Bone Under Physiological Conditions Including Various Types of Bone 88
4.2.1 Enchondral Ossification or Secondary Bone 89
4.2.2 Intramembranous Ossification, Primary Bone, or Woven Bone 90
4.3 In Vitro Evaluation of CaP Coatings 94
4.4 In Vivo Evaluation of Thin CaP Coatings 102
4.5 Considerations for Predicting Clinical Performance of CaP Coatings 108
References 112
Pulsed Laser Deposition of Thin Calcium Phosphate Coatings 115
5.1 Introduction 115
5.2 Description of the Technique 118
5.2.1 Mechanism of PLD 118
5.2.1.1 Interaction Between the Laser and the Calcium Phosphate Target 119
5.2.1.2 Dynamics of the Ablation Materials (Laser Plume) 122
5.3 Physicochemical Properties of PLD Coatings: Nucleation and Growth on the Substrate 124
5.3.1 Pressure Dependence 125
5.3.2 Temperature Dependence 126
5.3.3 Fluence Dependence 130
5.3.4 Pulse Repetition Rate Dependence 131
5.3.5 Preferential Orientation 132
5.3.6 Influence of the Substrate Material 133
5.3.7 Interface Between HA and Titanium 134
5.3.8 Octacalcium Phosphate Thin Films 135
5.3.9 Deposition on Other Materials 136
5.4 Modifications of the PLD Technique 137
5.5 Mechanical Properties of the PLD Coatings 139
5.5.1 Adhesive Bond Strength 139
5.5.2 Scratch Testing 141
5.5.3 Elastic Modulus and Hardness 143
5.6 In Vitro Evaluation 145
5.6.1 Dissolution Behavior 145
5.6.2 Cell Activity 148
5.6.2.1 PLD Coatings on Titanium Substrates 148
5.6.2.2 PLD Coatings on Polymer Substrates 152
5.7 Efficacy of PLD Coatings In Vivo 154
5.7.1 Study in Mongrel Dogs 154
5.7.2 Study in Rats 155
5.7.3 Studies in Minipigs 155
5.7.4 Studies in Rabbits 156
5.7.5 Studies in Beagle Dogs 158
5.8 Conclusions and Prospects for Applications 163
References 165
Ion Beam Techniques for Thin Calcium Phosphate Coating Production 170
6.1 Introduction 170
6.2 Ion Beam Technique 171
6.3 Coating Characterization 174
6.4 Mechanical Properties of Thin Coatings (Composites with Ceramics and Metals) 175
6.5 Change in Bond Strength and Solubility by Heat Treatment 176
6.6 Biological Responses 181
6.6.1 In Vitro Cell Behavior of Thin CaP Coatings 181
6.6.2 In Vivo Bone Behavior of Thin CaP Coatings 181
6.6.3 Immobilization of Bisphosphonates Through Thin CaP Coatings 182
6.7 Critical Assessment of Prospective Use 184
Appendix: Significant references for this chapter 185
References 185
Calcium Phosphate Coating Produced by a Sputter Deposition Process 188
7.1 Introduction 188
7.2 Sputtering Technique 193
7.3 Physicochemical Properties of Sputtered Coatings 194
7.4 Dissolution 198
7.5 In Vitro and In Vivo Biological Evaluation 200
7.5.1 In Vitro Study 201
7.5.2 In Vivo Study 202
7.6 Conclusion 204
References 206
Silicon-Substituted Hydroxyapatite Thin Films 212
8.1 Introduction 212
8.2 Production of SiHA Coatings 213
8.3 Physicochemical Characterization of SiHA Coating 215
8.4 In Vitro Study: Acellular Simulated Body Fluid 216
8.5 In Vitro Cell Culture 220
8.6 Conclusion 225
References 225
Electrochemically Assisted Deposition of Thin CaP Coatings 228
9.1 Introduction 228
9.1.4 Advantages of the ECAD Method 229
9.1.4 Disadvantages of the ECAD Method 229
9.2 ECAD: The Technique 230
9.2.1 Basic Principles 230
9.2.2 Influence of Processing Conditions on Coating Properties 233
9.2.2.1 Influence on Coating Composition 233
9.2.2.2 Influence on Coating Mass 234
9.2.3 Influence of Electrochemical and Solution Parameters 234
9.2.3.1 Processing with Constant Cell Voltage 235
9.2.3.2 Potentiostatic Processing 235
9.2.3.3 Galvanostatic Processing 240
9.2.3.4 Summary 247
9.2.4 Formation of Composite Coatings 248
9.2.4.1 Composite Coatings with Inorganic Additives 249
9.2.4.2 Composite Coatings with Organic Additives 249
9.2.4.3 Summary 254
9.2.5 Basic Principles of the Electrophoretic Deposition Process 254
9.3 Physicochemical Properties of Thin Coatings 255
9.4 Mechanical Properties of Thin Coatings 256
9.5 Similarities and Differences Between Plasma-Sprayed HA and Thin CaP Coating 259
9.6 Physicochemical Stability In Vitro and In Vivo 259
9.7 Biological Efficiency of the Thin CaP Coating 261
9.7.1 Cell Culture Investigations Using ECAD-CPP Coating 261
9.7.2 Animal Experimental Investigations 263
9.7.3 Experience from Clinical Applications 266
9.7.4 Summary 267
9.8 Characterization of Thin CaP Coating in Relation to the Regulatory Pathway 267
9.9 Critical Assessment on the Prospects of Future Industrial Applications (Advantages and Difficulties) 268
References 272
Electrosprayed Calcium Phosphate Coating for Biomedical Purposes 275
10.1 Introduction to Electrostatic Spray Deposition 275
10.2 Electrospraying 277
10.2.1 Conventional Spraying 277
10.2.2 Electrospraying 277
10.3 Physicochemical Properties of Electrosprayed CaP Coatings 278
10.3.1 Chemical Properties of Electrosprayed Coatings 278
10.3.1.1 Influence of Precursor Solution Parameters on Chemical Properties 278
10.3.1.2 Influence of Physical, Apparatus-Related Parameters on Chemical Properties 281
10.3.2 Morphological Properties of Electrosprayed Coatings 283
10.3.2.1 Influence of Physical, Apparatus-Related Parameters on Morphological Properties 283
10.3.2.2 Influence of Chemical, Precursor Solution Parameters on Morphological Properties 284
10.3.3 Conclusion 285
10.4 Mechanical Properties of Porous, Electrosprayed CaP Coatings 285
10.4.1 Fatigue Testing 286
10.4.2 Scratch Testing 287
10.4.3 Explantation of Dental Screw Implants 289
10.4.4 Conclusion 291
10.5 Similarities and Differences Between Plasma-Sprayed and Electrosprayed CaP Coatings 291
10.6 Physicochemical Stability In Vitro and In Vivo 292
10.6.1 In Vitro Soaking in Simulated Body Fluid 293
10.6.2 In Vivo Subcutaneous Implantation 296
10.6.3 Comparison Between In Vitro and In Vivo Studies 300
10.6.4 Conclusion 300
10.7 Efficacy of Porous, Electrosprayed CaP Coatings In Vivo 301
10.7.1 Implant Materials, Surgical Procedure, Implant Retrieval 301
10.7.2 Histological Evaluation 302
10.7.3 Histomorphometric Analysis 303
10.7.4 Discussion 304
10.7.5 Conclusion 305
10.8 Prospects of Future Industrial Applications 305
References 310
Biomimetic Coatings and Their Biological Functionalization 313
11.1 Introduction 313
11.2 Biomimetic Coatings 315
11.2.1 Biomimetic Coating Techniques 315
11.2.2 Characterization of Coatings 317
11.2.3 Typical Results Obtained Using the Standard Biomimetic Coating Process 317
11.2.4 Incorporation of Osteogenic Agents into Biomimetic Coatings: Biological Functionalization 318
11.3 Biomimetic CaP Coatings as a Delivery Vehicle for Osteogenic Drugs 319
11.3.1 In-Vitro Testing of the Osteogenic Potential of Biomimetic Coatings Bearing BMP-2 320
11.3.2 In-Vivo Testing of the Osteogenic Potential of Biomimetic Coatings Bearing BMP-2 320
11.3.2.1 Ectopic Ossification Model in Rats 320
11.3.2.2 Orthotopic Ossification Model in Miniature Pigs 321
11.4 Biologically Functionalized Biomimetic Coatings 323
11.5 Conclusions 324
References 324
Prospects for Future Applications 327
Index 329