Title Page
Contents
ABSTRACT 7
1. Introduction 10
1.1. Conventional Methods of Transfection 10
1.2. High-aspect-ratio Nanostructures 10
1.3. Nanoneedle-mediated Intracellular Delivery 12
1.3.1. Parameters of Nanoneedles 12
1.3.2. Nanoneedle-mediated Intracellular Delivery with Centrifugal Force as External Force to Aid Spontaneous Penetration of the Cell Membrane 12
2. Materials and Methods 15
2.1. Silicon Nanostructure Fabrication 15
2.2. Scanning Electron Microscopy 15
2.3. Cell Culture 15
2.4. Intracellular Delivery 16
2.5. Flow Cytometry Analysis 16
3. Results and Discussion 18
3.1. Cell-nanostructure Interface Modeling 18
3.2. Nanoneedle Fabrication 21
3.2.1. Fabrication of Short Nanocones 21
3.2.2. Fabrication of Nanoneedle Elastomer Patches 23
3.2.3. Fabrication of Vertical Nanopillars 25
3.2.4. Fabrication of Conical Silicon Nanoneedles 27
3.3. Establishment of Intracellular Delivery Workflow 29
3.3.1. Effect of Nanostructure Dimensions and Surface Coating 29
3.3.2. Demonstration of Enhanced Endocytosis on Nanoneedles 32
3.3.3. Cell-nanostructure Binding Protocol 34
3.3.4. Pitch distance and Centrifugation Speed 39
3.4. Validation of Direct Penetration-mediated Delivery - a Mechanistic Study 41
3.4.1. Time Window of Exogenous Cargo Exposure 41
3.4.2. Cargo Size Independence 41
4. Conclusion and Future Works 43
References 45