Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2018 Engineering 3D systems with tunable mechanical properties to mimic the tumor microenvironment Shalini Raj Unnikandam Veettil Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Chemical Engineering Commons Recommended Citation Unnikandam Veettil, Shalini Raj, "Engineering 3D systems with tunable mechanical properties to mimic the tumor microenvironment" (2018). Graduate Theses and Dissertations. 17339. https://lib.dr.iastate.edu/etd/17339 This Thesis is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Engineering 3D systems with tunable mechanical properties to mimic the tumor microenvironment by Shalini Raj Unnikandam Veettil A thesis submitted to the graduate faculty in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Major: Chemical Engineering Program of Study Committee: Ian C Schneider, Major Professor Kaitlin Bratlie Michael Bartlett The student author, whose presentation of the scholarship herein was approved by the program of study committee, is solely responsible for the content of this thesis. The Graduate College will ensure this thesis is globally accessible and will not permit alterations after a degree is conferred. Iowa State University Ames, Iowa 2018 Copyright © Shalini Raj Unnikandam Veettil, 2018. All rights reserved. ii DEDICATION This thesis is dedicated to my family and friends who have been a great source of support. iii TABLE OF CONTENTS Page ABBREVIATIONS ............................................................................................................. vi ACKNOWLEDGMENTS ................................................................................................. vii ABSTRACT ....................................................................................................................... viii CHAPTER 1. INTRODUCTION ........................................................................................1 1.1Motivation ....................................................................................................................1 1.2 Background and Introduction ......................................................................................2 1.2.1 Metastasis requires directed migration ................................................................2 1.2.2 Cells produce, remodel and degrade extracellular matrix ...................................3 1.2.3 Cell - ECM interactions and regulation of cellular responses .............................4 1.2.4 Techniques used to tune stiffness ........................................................................6 1.2.5 Cell morphology and migration in 2D systems with tunable mechanical properties ......................................................................................................................8 1.2.6 3D systems with tunable mechanical properties .................................................9 1.2.7 Durotaxis ...........................................................................................................11 CHAPTER 2. RESEARCH OBJECTIVES .....................................................................13 2.1 Develop and Characterize a TME Mimicking 3D System with Tunable Mechanical Properties .....................................................................................................13 2.2 Evaluate How Cell Migration and Morphology Vary in 3D as a Function of Gel Thickness and Surface Chemistry Linking the Soft and Stiff Interface ..........................14 2.3 Examine if Durotactic Responses Could Be Elicited in the Surface Tunable 3D Systems ............................................................................................................................15 CHAPTER 3. TUNING SURFACE FUNCTIONALIZATION AND COLLAGEN GEL THICKNESS TO REGULATE CANCER CELL MIGRATION ........................16 3.1 Abstract ......................................................................................................................16 3.2 Highlights ..................................................................................................................17 3.3 Introduction ...............................................................................................................18 3.4 Material and Methods ................................................................................................21 3.4.1 Surface modifications generating high and low collagen binding surfaces ......21 3.4.2 Characterization of amine density on glass surfaces .........................................21 3.4.3 Contact angle measurement ...............................................................................22 3.4.4 Adhesion characterization .................................................................................22 3.4.5 Cell culture and characterization of cell morphology on 2D functionalized glass surfaces ..............................................................................................................23 3.4.6 Preparation of collagen gel in 3D chambers .....................................................24 3.4.7 Fixing and staining of cells ...............................................................................25 3.4.8 Data Analysis ....................................................................................................25 3.4.9 Statistical analysis .............................................................................................26 iv 3.5 Results .......................................................................................................................27 3.5.1 Surface modification of glass generating high and low collagen binding surfaces .......................................................................................................................27 3.5.2 Cell spreading on 2D functionalized glass surfaces ..........................................28 3.5.3 Adhesion of collagen to functionalized glass surfaces ......................................28 3.5.4 Quantitative cell morphology in 3D collagen chambers with different glass functionalization .........................................................................................................29 3.5.5 Cell motility in 3D collagen chambers with different glass functionalization ..31 3.6 Discussion ..................................................................................................................33 3.7 Conclusions ...............................................................................................................37 3.8 Acknowledgements ...................................................................................................38 3.9 Competing Interests ...................................................................................................38 3.10 Contributions ...........................................................................................................38 3.11 References ...............................................................................................................39 3.12 Figure Legends ........................................................................................................44 4.1 Investigating the Biophysical Effects of Hyaluronan Molecular Weight and Concentration on Breast Cancer Cell Migration in Collagen Matrices ...........................54 4.2 Investigating the Influence of Surface Topographical Cues to Elicit Durotaxis in 3D Systems Among Breast Cancer Cells ........................................................................56 REFERENCES ....................................................................................................................59 APPENDIX. MATLAB CODE ..........................................................................................68 v LIST OF FIGURES Page Figure 1 Characterization of surface properties on functionalized glass surfaces ..................44 Figure 2 Characterization of cell spreading on functionalized glass surfaces. ........................45 Figure 3 Characterization of adhesion of collagen to functionalized glass surfaces. ..............46 Figure 4 Characterization of cell morphology in 3D collagen chambers of different thicknesses and glass functionalization. ....................................................................47 Figure 5 Characterization of cell shape in 3D collagen chambers of different thicknesses and glass functionalization ........................................................................................49 Figure 6 Motility characterization in 3D collagen chambers with functionalized glass surfaces. .....................................................................................................................50 Figure 7 Motility characterization in 3D collagen chambers with step change in thickness ...52 Figure 8 The structure of hyaluronan consisting of repeating disaccharides of glucuronic acid and N-acetylglucosamine ...................................................................................56 Figure 9 Schematic of pyramidal 3D structure used to provide soft-stiff interfaces (scale