UNIVERSITY OF CALIFORNIA, IRVINE Kinetic Studies of Multivalent Nanoparticle Adhesion DISSERTATION submitted in partial satisfaction of the requirements for the deGree of DOCTOR OF PHILOSOPHY in Biomedical EnGineerinG by MinGqiu WanG Dissertation Committee: Assistant Professor Jered Haun, Chair Associate Professor Jun Allard Professor YounG Jik Kwon 2018 © 2018 MinGqiu WanG DEDICATION To my parents, for their unconditional love and support. ii TABLE OF CONTENTS DEDICATION.......................................................................................................................... II TABLE OF CONTENTS........................................................................................................ III LIST OF FIGURES .................................................................................................................. V LIST OF TABLES ................................................................................................................. VII ACKNOWLEDGMENTS ..................................................................................................... VIII CURRICULUM VITAE ........................................................................................................... X ABSTRACT OF THE DISSERTATION ............................................................................... XI 1. INTRODUCTION ........................................................................................................... 1 1.1. TARGET NANOPARTICLE ADHESION ............................................................................................. 1 1.2. NANO ADHESIVE DYNAMICS (NAD) SIMULATION AND KINETIC ANALYSIS ......................... 2 2. BACKGROUND .............................................................................................................. 5 2.1. MULTIVALENT NANOPARTICLE ADHESION ................................................................................. 5 2.2. FLOW CHAMBER ASSAY ................................................................................................................... 6 2.3. ADHESION MODEL ........................................................................................................................... 7 2.4. BROWNIAN DYNAMICS .................................................................................................................... 8 2.5. BIRTH AND DEATH MODEL ............................................................................................................. 9 3. MODEL DEVELOPMENT ........................................................................................... 11 3.1. OVERVIEW OF NANO ADHESIVE DYNAMICS (NAD) SIMULATION ........................................ 11 3.2. NANOPARTICLE MOTION ............................................................................................................. 11 3.3. NANOPARTICLE ADHESION ......................................................................................................... 16 3.4. ADHESION MOLECULE CONFIGURATIONS ON SURFACE .......................................................... 19 3.5. PARAMETERS................................................................................................................................. 20 3.6. COMPUTATION DETAILS .............................................................................................................. 23 3.7. ATTACHMENT AND DETACHMENT RATES ................................................................................ 24 4. THE EVOLUTION OF PARTICLE DETACHMENT ................................................. 26 iii 4.1. INTRODUCTION ............................................................................................................................. 26 4.2. METHODS ....................................................................................................................................... 27 4.3. GENERAL DYNAMICS OF NANOPARTICLES AND BONDS .......................................................... 30 4.4. TRACKING BOND DISTRIBUTIONS .............................................................................................. 36 4.5. MECHANICAL STATE DIAGRAM ................................................................................................... 41 4.6. MEASURING � USING OPTICAL TWEEZERS ............................................................................... 45 4.7. FINAL FITTING OF EXPERIMENTAL DATA.................................................................................. 46 4.8. DISCUSSION.................................................................................................................................... 54 5. HETEROGENEITY IN MULTIVALENT NANOPARTICLE ..................................... 64 5.1. INTRODUCTION ............................................................................................................................. 64 5.2. METHODS ....................................................................................................................................... 64 5.3. BOND POTENTIAL (BP) DETACHMENT MODEL ..................................................................... 77 5.4. RELATING PARAMETERS FOR THE BP AND EMPIRICAL MODELS ........................................ 84 5.5. BOND STATE MODEL TO DETERMINE TRANSITION RATES.................................................. 86 5.6. ESTIMATING NANOPARTICLE DETACHMENT RATE FROM TRANSITION RATES ............... 89 5.7. OBTAINING DETACHMENT RATES FOR ALL SUB-POPULATIONS ........................................ 90 5.8. DISCUSSION................................................................................................................................. 116 6. NAD ATTACHMENT SIMULATIONS .................................................................... 121 6.1. INTRODUCTION .......................................................................................................................... 121 6.2. METHODS .................................................................................................................................... 121 6.3. GENERAL DYNAMICS OF NANOPARTICLE ATTACHMENT ..................................................... 124 6.4. INFLUENCE OF BOX HEIGHT AND ADHESION MOLECULE DENSITY ..................................... 125 7. CONCLUSION AND FUTURE DIRECTIONS ......................................................... 127 REFERENCES .................................................................................................................... 130 iv LIST OF FIGURES FiGure 3.1 Size-scaled depiction of the adhesion molecule system employed. ........................... 19 FiGure 3.2 OptimizinG simulations. ................................................................................................................... 24 FiGure 4.1 AlGorithm for NAD detachment simulations in which nanoparticles were initiated with a sinGle bond. ........................................................................................................................ 28 FiGure 4.2 Nanoparticle and bond dynamics. .............................................................................................. 31 FiGure 4.3 Total bond numbers versus time and �.................................................................................... 33 FiGure 4.4 Bond biophysics and dynamics. ................................................................................................... 35 FiGure 4.5 Bond biophysics and reaction rates. .......................................................................................... 36 FiGure 4.6 Bond valency distributions and bond potential. .................................................................. 38 FiGure 4.7 Bond number dynamics. .................................................................................................................. 39 FiGure 4.8 Corrected bond distributions to reveal bond potential. ................................................... 40 FiGure 4.9 Mechanical state diaGram. .............................................................................................................. 43 FiGure 4.10 Dynamic force spectroscopy usinG optical tweezers. ..................................................... 44 FiGure 4.11 Final fittinG of experiments for different ICAM-1 clusterinG conditions. .............. 48 FiGure 4.12 Bond numbers for all ICAM-1 confiGurations. .................................................................... 53 FiGure 4.13 Mean bond potential for dimer and monomer cases. ..................................................... 53 FiGure 4.14 SinGle tether simulations and valency state-dependent detachment dynamics. ................................................................................................................................................................................... 57 FiGure 4.15 SinGle tether simulations. ............................................................................................................. 58 FiGure 5.1 Bond transition rate model fittinG parameters. ................................................................... 72 FiGure 5.2 Full population BP model fits for two components usinG 2 and 3 deGrees of freedom. ................................................................................................................................................................ 78 FiGure 5.3 BP model analysis of the base case............................................................................................