University of Massachusetts Amherst ScholarWorks@UMass Amherst Doctoral Dissertations Dissertations and Theses March 2015 Stimuli-Responsive Supramolecular Assembly, Disassembly and Implications JING GUO University of Massachusetts Amherst Follow this and additional works at: https://scholarworks.umass.edu/dissertations_2 Part of the Organic Chemistry Commons Recommended Citation GUO, JING, "Stimuli-Responsive Supramolecular Assembly, Disassembly and Implications" (2015). Doctoral Dissertations. 300. https://doi.org/10.7275/6379852.0 https://scholarworks.umass.edu/dissertations_2/300 This Open Access Dissertation is brought to you for free and open access by the Dissertations and Theses at ScholarWorks@UMass Amherst. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. STIMULI-RESPONSIVE SUPRAMOLECULAR ASSEMBLY, DISASSEMBLY AND IMPLICATIONS A Dissertation Presented by JING GUO Submitted to the Graduate School of the University of Massachusetts Amherst in partial fulfilment of the requirements for the degree of DOCTOR OF PHILOSOPHY February 2015 Department of Chemistry Copyright by Jing Guo 2015 All Rights Reserved STIMULI-RESPONSIVE SUPRAMOLECULAR ASSEMBLY, DISASSEMBLY AND IMPLICATIONS A Dissertation presented by JING GUO Approved as to style and content by: _________________________________ S. Thayumanavan, Chair _________________________________ Paul M. Lahti, Member _________________________________ Ricardo B. Metz, Member _________________________________ Ryan C. Hayward, Member _________________________________ Craig T. Martin, Department Head Department of Chemistry DEDICATION To my husband Jeffrey, my parents, and my son ACKNOWLEDGEMENTS First of all, I need to thank of the University of Massachusetts Amherst Chemistry Department for giving me such an invaluable chance to study here. Thank you to my advisor and mentor, Professor Sankaran Thayumanavan, for the chance to do research in such a wonderful research group. Thank you for all of the direction, support and encouragement, both academic and personal advice during the past five years. I am sure those directions will benefit me in my future life. Without his help, I could not have made it this far. I would also like to thank my committee members, Professor Paul M. Lahti, Professor Ricardo B. Metz and Professor Ryan C. Hayward, for their guidance and insight. I truly appreciate the directions from my committee members and motivations that support me to make all the improvements as a Ph.D. candidate. Thank you for all that you have done for me. I would also like to thank my collaborators and colleagues that have contributed to my research: Dr. Nagamani (“Mani”) Chikkannagari for her mentorship during the early years of my graduate career and collaborations in proton conducting material projects; Dr. Volkan Yesilyurt for his mentorship when I switched to stimuli-responsive assembly projects and the inspiration of size-tunable nanoparticles project; Jiaming Zhuang for all the brilliant advice in experimental design and TEM measurements; Oyuntuya Munkhbat for helping me with conducting measurements and synthesizing linker molecules; Krishna R. Raghupathi for providing coumarin azide molecules; Dr. Diego Amado Torrez for providing biotin azide molecules; Dr. Ayyagari Venkata Subrahmanyam (“Subbu”) and Bo Zhao for synthesis help; Dr. Ambata Poe for AFM measurements; and Dr. Feng Wang for v surface tension and LCST measurements. I would like to thank the dendrimer subgroup for fruitful discussions, and all Thayumanavan group members, past and present, for their synthetic aid, advice, and friendship. I would like to thank our group assistant Karen Hakala for her help, listening and support, as well as UMass Chemistry staff Dennis Glick and J.M. Stowe. I would like to thank my friends I met in UMASS, Xiaobo Shen, Chengbei Li, Sheng Chu, Yujie Liu, Ying Qi, Yue Zhang, Meili Yang and Yihui Yang. We travelled on the same airplane to the U.S and started this wonderful journey together, and I am truly happy to have had your friendship and company, both then and now. Best wishes to you all! I would like to thank my family and my parents, Mingxiang Guo and Xiuzhu Guo for constant support in all my life choices. As the only child of my parents, I could not stay close and take care of them for so many years, and I thank my cousins for taking care of my parents in my absence. I thank my parents for believing in me and my ability to get this far. I also would like to thank my new family here in U.S., My father-in-law Gary Lucas, my mother-in-law Catherine Lucas, and my sister-in-law Erica Bush for welcoming me into your family with your generous love. Finally I would like to thank my husband, Dr. Jeffrey Lucas. Along with the knowledge and friendship I found here in UMASS, my husband is the best gift that UMass gave me. Thank you for all of your listening, your company, your encouragement，and your love. Life is full of hopes and dreams with you. J&J, forever. vi ABSTRACT STIMULI-RESPONSIVE SUPRAMOLECULAR ASSEMBLY, DISASSEMBLY AND IMPLICATIONS FEBRUARY 2015 JING GUO, B.E., B.A., UNIVERSITY OF ELECTRONIC SCIENCE AND TECHNOLOGY OF CHINA M.S., CHINESE ACADEMY OF SCIENCES PH.D., UNIVERSITY OF MASSACHUSETTS AMHERST Directed by: Professor Sankaran Thayumanavan Stimuli-responsive systems have attracted wide interest due to their applications in a variety of areas such as drug delivery and sensing. Stimuli-responsive systems that are triggered by secondary biological changes have been studied extensively. Primary biological changes, such as protein imbalances and enzymatic activity, are intrinsic to certain types of diseases, and thus have drawn increasing attention in triggering stimuli- responsive systems in areas such as drug delivery. This thesis first provides a concept of increasing stimuli-responsive selectivity by designing a system that only responds in the concurrent presence of two complementary primary biological stimuli, protein and enzyme. A dendritic assembly platform was used to test this concept. Each dendron was equipped with a protein specific binding ligand and an enzymatic responsive moiety. The results showed release of the report units that were covalently attached to dendrons when two stimuli concurrently presented, while no obvious release was observed with one trigger vii alone. By locking the aggregates in their aggregated state, this response is turned off, and unlocking the assembly resumes the dual triggered disassembly process. With the need to test the concept of dual triggered release without covalently attached report units, the thesis also investigated the above-mentioned concept with non- covalently attached dye molecules as report units, as in a real-life application, synthesis of a prodrug is not always feasible. Again, the studies showed faster initial rate of release and more overall release with two stimuli in comparison to one stimulus alone. Mix micelles, a system that mixed two dendrons with different protein specific binding ligand, were prepared to introduce a multi-stimuli responsive feature. The results showed mix micelles can respond to two protein stimuli as well as to enzymatic activity. Stable and size-tunable aggregates are also drawing the attention of the scientific community for utilization in a variety of applications in biomaterials and sensing materials. This thesis also demonstrates the design of aggregates whose size is tunable by taking advantage of the lower critical solution temperature (LCST) behavior of polyethylene glycol (PEG). The aggregates were then crosslinked through thiol-yne Click chemistry to stabilize the aggregate size, and upon incorporating the appropriate stimulus, the crosslinked aggregates were disassembled. viii TABLE OF CONTENTS Page ACKNOWLEDGEMENTS ................................................................................................................ v ABSTRACT ...................................................................................................................................... vii LIST OF TABLES ............................................................................................................... xii LIST OF FIGURES ........................................................................................................... xiii LIST OF SCHEMES........................................................................................................... xvi LIST OF CHARTS ............................................................................................................ xvii CHAPTER 1. INTRODUCTION .....................................................................................................1 1.1 Introduction ...........................................................................................................1 1.2 Facially Amphiphilic Dendrons ...........................................................................2 1.3 Stimuli-Sensitive Amphiphilic Assemblies .........................................................5 1.3.1 Secondary Stimuli Responsive Amphiphilic Dendrons ........................5 1.3.2 Primary Stimuli Responsive Amphiphilic Dendrons .............................8 1.4 Thesis Overview ................................................................................................16 1.5 References ..........................................................................................................17