Advances in Planar Lipid Bilayers and Liposomes (eBook)

Front Cover 1
Advances in Planar Lipid Bilayers and Liposomes 4
Copyright Page 5
Contents 6
Contributors 12
Preface 16
Chapter 1: Current Perspectives in Liposome-Encapsulated Hemoglobin as Oxygen Carrier 18
1. Introduction 19
2. Lipid Composition of LEH 21
3. PEG Modification of LEH Surface 23
4. Hemoglobin Source 24
5. Particle Size 25
6. Hemoglobin and Oxygen Affinity 26
7. Viscosity of LEH Preparation 28
8. Oncotic Pressure and Isotonocity 29
9. Hemoglobin Auto-oxidation and Methemoglobin Formation 30
10. Current Manufacturing Technology 32
11. Toxicological Issues 33
12. In Vivo Biodisposition 35
13. Physiological and Survival Studies in Animal Models of Hemorrhagic Shock 37
14. Summary 37
Acknowledgments 38
References 38
Chapter 2: Electric Conductance of Planar Lipid Bilayer as a Tool for the Study of Membrane Pore Selectivity and Blockade 46
1. Introduction 47
1.1. Theoretical Background 49
1.2. Formulation of the Experimental Problem 56
2. Experimental 56
2.1. Lipids 56
2.2. Poly(ethylene)glycols 56
2.3. Differential Scanning Calorimetry 57
2.4. Planar BLMs 57
2.5. Electrical Measurements 57
2.6. Lipid Pore Size Evaluation 57
2.7. Poly(ethylene)glycol Method 57
2.8. Estimation of Membrane Surface Tension sigma 58
2.9. Estimation of Single Lipid Pore Edge Tension gamma 59
3. Results 60
3.1. Registration of Lipid Pore Population Appeared in pBLM from DPPC at the Lipid Phase Transition Temperature 60
3.2. Lipid Phase Transition in pBLM and Electric Current Fluctuations 62
3.3. The Appearance of Single Lipid Pores in the pBLM from Natural Phospholipids 65
3.4. Line Edge Tension of Lipid Pore 65
3.5. Evaluation of Lipid Bilayer Stability 67
3.6. Blocking Effect of PEGs on Single Lipid Pore Conductance 69
4. Discussion 76
5. Conclusion 78
Acknowledgments 79
References 79
Chapter 3: Physicochemical and Pharmacokinetic Characterization of Ultradeformable Vesicles using Calcein as Hydrophilic Fluorescent Marker 82
1. Introduction 83
2. Physicochemical Characterization of Ultradeformable Vesicles 85
2.1. Composition and Process of Preparation 85
2.2. Mean Hydrodynamic Diameter and Deformability 86
2.3. Encapsulation Efficiency of Calcein: Influence of the Formulation Final Concentration 86
2.4. Membrane Permeability to Calcein 88
3. Pharmacokinetics of Calcein from Ultradeformable Vesicles 90
3.1. In Vitro Skin Permeation of Calcein 90
3.2. In Vivo Studies of the Transdermal Absorption of Calcein to the Blood Circulation 93
3.2.1. Validation of fluorometric method for determination of calcein in plasma 93
3.2.2. Pharmacokinetic of calcein in the plasma of hairless mice after topical application 95
4. Concluding Remarks: New Model for the Mode of Action of Ultradeformable Vesicles 98
Acknowledgments 101
References 101
Chapter 4: Electrical Methods for Determining Surface Charge Density and Electrolyte Composition at the Lipid Bilayer-Solution Interface 104
1. Introduction 105
2. Bilayer Capacitance as a Probe for Bilayer Surface Potential 108
3. Apparatus for Measuring Perfusion Induced Current Transients in Lipid Bilayers 109
4. Exchange of Solutions Induced Bilayer Current Transient 111
5. Deriving Surface Potential and Surface Charge Density from Capacitive Current 113
6. Bilayer Capacitive Currents can be Used to Monitor Solution Exchange 117
7. Bilayer Capacitive Currents can be Used to Monitor Changes in Lipid Composition 118
8. Conclusions 120
Acknowledgments 120
References 120
Chapter 5: Micropatterned Lipid Bilayer Membranes on Solid Substrates 124
1. Introduction 125
1.1. Substrate-Supported Planar Lipid Bilayers 125
1.2. Micropatterning Substrate-Supported Planar Lipid Bilayers 125
1.3. Micropatterned Composite Membrane of Polymerized and Fluid Lipid Bilayers 126
2. Lithographic Polymerization of Lipid Bilayers 130
3. Incorporation of Fluid Lipid Bilayers 134
4. Controlling the Ratios of Polymerized and Fluid Lipid Bilayers 139
5. Incorporation of Biological Membranes into Micropatterned Bilayers 143
6. Conclusions and Outlook 145
Acknowledgments 146
References 147
Chapter 6: Salt-Induced Morphological Transitions in Nonequimolar Catanionic Systems: Spontaneous Formation of Blastulae Aggregates 152
1. Introduction 153
1.1. Self-Assembly of Amphiphilic Molecules 153
1.2. Spontaneous Formation of Vesicles 154
1.3. Catanionic Surfactant Mixtures 156
1.4. Application of Catanionic Vesicles in Cosmetic and Drug Delivery 157
1.5. The Present Study 158
2. Experimental Procedures 159
2.1. Materials 159
2.2. Sample Preparation 159
2.3. Dynamic Light Scattering Measurements 159
2.4. Rheology 160
2.5. Cryo-Transmission Electron Microscopy (cryo-TEM) 160
2.6. Freeze-Fracture Electron Microscopy 160
3. Results 160
3.1. Characterization of SDS/DTAB Micellar Solution 160
3.2. Salt-Induced Micelle-to-Vesicle Transition 162
4. Discussion 166
4.1. Models of the Micelle-to-Vesicle Transition 166
4.1.1. Lamellar model 166
4.1.2. Clustering model 168
4.2. Blastulae Vesicles 168
4.3. The Occurrence of Convex-Concave Patterns in Biological Systems 169
4.4. Raspberry Vesicles 170
4.5. Blastulae Vesicles: A General Trend in Catanionic Systems? 171
5. Conclusions 172
References 172
Chapter 7: Transformation Between Liposomes and Cubic Phases of Biological Lipid Membranes Induced by Modulation of Electrostatic Interactions 180
1. Introduction 181
2. Effects of Surface Charges due to Charged Lipids on the Stability of the Q Phases 188
3. Effects of Surface Charges due to Adsorbed Charged Peptides on the Stability of the Q Phases 193
4. Mechanism of the Electrostatic Interactions-Induced Phase Transition Between the Q Phase and the L? Phase 198
5. Effects of Ca2+ and pH on the Phase Transition Between the L? Phase and the Q Phases 204
6. Effects of Charged Peptides and Osmotic Stress on the Stability of the Q Phases of the Charged Lipid Membranes 212
7. Conclusion 217
Appendix: Spontaneous Curvature of Monolayer Membranes 218
Acknowledgments 222
References 222
Chapter 8: The Impact of Astrocytes in the Clearance of Neurotransmitters by Uptake and Inactivation 228
1. Astrocytes 229
1.1. Structure 230
1.2. Metabolic Support 230
1.3. Blood-Brain Barrier 232
1.4. Regulation of Ion Concentration in Extracellular Space 232
1.5. Vasomodulation 232
1.6. Transmitter Uptake and Release 232
2. Neurotransmitters 233
3. Transporters 233
3.1. Glutamate Uptake 235
3.2. GABA Uptake 238
3.3. Glycine Uptake 239
3.4. Noradrenaline Uptake 240
3.5. Serotonin Uptake 240
3.6. Dopamine Uptake 241
3.7. Histamine Uptake 242
3.8. Organic Cation Transporters 242
4. Drugs Affecting Transport Function 243
5. Conclusion 245
Acknowledgments 246
References 246
Chapter 9: Stability of the Inverted Hexagonal Phase 254
1. Introduction 255
1.1. Mathematical Description of Membrane Curvature 257
1.2. Influence of Spontaneous Curvature on the Self-Assembling Process 259
2. Inverted Hexagonal Phase 261
2.1. Relevance of Nonlamellar Phases in Biological Systems 261
2.2. Geometry of the Inverted Hexagonal Phase 261
2.3. Models of the Transition of the Lamellar to Inverted Hexagonal Phase 263
2.4. Models of Free Energy of the Inverted Hexagonal Phase 265
3. Free Energy of Lipid Monolayers 269
3.1. Bending Energy of Lipid Monolayers 269
3.2. Interstitial Energy of the Inverted Hexagonal Phase 275
3.3. Total Free Energy per Lipid Molecule 277
4. Estimation of Model Constants 278
5. Determination of Equilibrium Configuration of Planar and Inverted Cylindrical Systems 279
5.1. Numerical Solution 279
5.2. Results of Equilibrium Configurations of Planar and Inverted Cylindrical Systems 279
5.3. Influence of the Direct Interaction Constant 284
6. Lamellar to Inverted Hexagonal Phase Transition 284
6.1. Determination of Pivotal Map of Nucleation Contour by Minimization of Monolayer Bending Energy 284
6.2. Determination of Equilibrium Configuration of Lamellar to Inverted Hexagonal Phase Transition by Monte Carlo Simulated Ann 287
6.3. Results: Equilibrium Configuration of Nucleation of the Lamellar to Inverted Hexagonal Phase Transition 288
7. Discussion and Conclusions 291
Acknowledgments 292
References 292
Chapter 10: Attraction of Like-Charged Surfaces Mediated by Spheroidal Nanoparticles with Spatially Distributed Electric Charge: Theory and Simulation 296
1. Introduction 297
2. Theoretical Model 299
2.1. Including the Excluded Volume Effect 305
2.2. Excluding the Excluded Volume Effect 307
2.3. Numerical Methods 308
2.4. Monte Carlo Simulation 308
3. Results 309
4. Concluding Remarks 314
References 315
Subject Index 320