Acute and Chronic Neural Stimulation via Mechano-Sensitive Ion Channels (eBook)

Andy Kah Ping Tay received his PhD in Bioengineering from the University of California, Los Angeles. He has published over 20 articles, with more under review, and is the recipient of 7 academic awards in 2017 alone, including the SciFinder® Future Leaders Program from the American Chemical Society, and the TUM Postdoc Mobility Grant from Technical University of Munich.

Dedication 6
Foreword 7
Preface 9
Acknowledgments 11
Contents 13
About the Author 16
Chapter 1: Micro- and Nanotechnologies to Probe Brain Mechanobiology 17
1.1 Introduction 17
1.2 Tools to Explore the Effects of Biomechanical Forces on the Brain 21
1.2.1 Conventional Tools 21
1.2.2 Microtechnology Tools 24
1.2.3 Nanotechnology Tools 25
1.3 Effects of Biomechanical Forces on Cellular Functions 26
1.3.1 Regulation of Gene Expression and Calcium Influx 26
1.3.2 Regulation of Synapses and Neurotransmitter Release 31
1.3.3 Regulation of Neurite Growth 33
1.3.4 Regulation of Circuitry and Plasticity 35
1.3.5 Regulation of Brain Folding 36
1.3.6 Traumatic Brain Injuries 37
1.4 Conclusions 38
References 39
Chapter 2: Acute Neural Stimulation 46
2.1 Introduction 46
2.2 Results and Discussions 48
2.2.1 Experimental Setup 48
2.2.2 Characterization of Starch- and Chitosan-Coated MNPs 48
2.2.3 Location and Uptake of MNPs 50
2.2.4 Nano-Magnetic Forces Induce Ca2+ Influxes 51
2.2.5 The Location of MNPs Affected the Response of Cortical Neural Networks to Nano-Magnetic Forces 53
2.2.6 Mechanism of Stimulation 53
2.2.7 Lipid Bilayer Stretch Model 57
2.3 Conclusions 57
2.4 Materials and Methods 60
2.4.1 Fabrication of Magnetic Chips 60
2.4.2 Cortical Neural Culture 61
2.4.3 Characterization of Nanoparticle Properties 61
2.4.4 Nanoparticle Incubation 62
2.4.5 Calcium Dye Incubation and Magnetic Force Stimulation 62
2.4.6 Immunofluorescent Labeling 63
2.4.7 Cytotoxicity Assay 63
2.4.8 Flow Cytometry Analysis 63
2.4.9 Image Acquisition, Analysis, and Statistical Evaluations 63
References 64
Chapter 3: Chronic Neural Stimulation 69
3.1 Modulation of Excitatory: Inhibitory Ion Channel Ratio in Neurons with Magnetic Stimulation 69
3.2 Conclusions 71
3.3 Materials and Methods 73
3.3.1 Quantification of Magnetic Forces 73
3.3.2 Chronic Magnetic Force Stimulation 73
3.3.3 Statistical Significance 74
References 74
Chapter 4: Phenotypic Selection of Magnetospirillum magneticum (AMB-1) Over-Producers Using Magnetic Ratcheting 75
4.1 Introduction 75
4.2 Results and Discussions 77
4.2.1 Development of Magnetic Ratcheting Platform 77
4.2.2 Generation of AMB-1 Library with Magnetic Ratcheting 77
4.2.3 The Properties of Magnetosomes Produced by Over-­producers Were Similar to Wild Type 77
4.3 Conclusions 79
4.4 Materials and Methods 80
4.4.1 Culture Conditions 80
4.4.2 Characterization of Cellular Magnetization (Cmag) 81
4.4.3 Isolation of Magnetosomes 81
4.4.4 SQUID Characterization 81
4.4.5 Chip Fabrication 81
4.4.6 Automated Ratcheting System and Particle Experiments 82
4.4.7 Electron Microscopy 82
References 82
Chapter 5: Magnetic Microfluidic Separation for Estimating the Magnetic Contents of Magnetotactic Bacteria 85
5.1 Introduction 85
5.2 Results and Discussions 86
5.2.1 Design of Magnetic Microfluidic Device 86
5.2.2 Optimizing Flow Ratio with Particles 86
5.2.3 Minimizing Flagella Motion 88
5.2.4 Assessing the Precision of Quantitative Estimation of Magnetic Contents in AMB-1 Mutants 88
5.2.5 Parallelized Design for Microfluidic Bioreactor 91
5.3 Conclusions 92
5.4 Materials and Methods 92
5.4.1 Microfabrication 92
5.4.2 Device Characterization with Beads 93
5.4.3 Magnetic Field Measurements 93
5.4.4 Culture Conditions 93
5.4.5 Trajectory Tracking 94
5.4.6 Microscopy 94
5.4.7 Electron Microscopy 94
5.4.8 Statistical Analysis 94
References 95
Chapter 6: Outlook for Magnetic Neural Stimulation Techniques 96
6.1 Reporters of Magnetic Stimulation 96
6.2 Nanotechnology 97
6.2.1 Microfluidics for Magnetic Nanoparticle Synthesis 98
6.2.2 Magnetotactic Bacteria for Magnetosomes and Magnetic Nanoparticles 98
6.2.3 Magnetic Nanoparticles for Crossing the Blood–Brain Barrier 99
6.2.4 Minimizing Cytotoxicity from Magnetic Nanoparticles 100
6.3 Energy-Delivering Devices 101
6.4 Conclusions 102
References 103
Appendix A: Supporting Information for Chap. 2 107
Appendix A.1: Example to Calculate Magnetic Force 107
Appendix B: Supporting Information for Chap. 3 113
Appendix C: Supporting Information for Chap. 4 115
Appendix C.1: Design of Magnetic Ratcheting Platform 115
Appendix D: Supporting Information for Chap. 5 122
References 127