Plasma Proteins and Their Interaction with Synthetic Polymers at the Air-Water Interface

University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2013 Plasma Proteins and Their interaction With Synthetic Polymers at the Air-Water interface Zhengzheng Liao University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Physical Chemistry Commons Recommended Citation Liao, Zhengzheng, "Plasma Proteins and Their interaction With Synthetic Polymers at the Air-Water interface" (2013). Publicly Accessible Penn Dissertations. 774. https://repository.upenn.edu/edissertations/774 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/774 For more information, please contact [email protected]. Plasma Proteins and Their interaction With Synthetic Polymers at the Air-Water interface Abstract The adsorption of proteins and synthetic polymers at the air-water interface (AWI) has broad significance in biomedicine and biotechnology. Protein behavior at the AWI can be guided to control the structure of the two-dimensional biopolymer film. In addition, synthetic polymers affect how plasma proteins act on implant or drug carrier surfaces, and can also decrease the potential for gas embolism. In this thesis, fluorescence microscopy was applied in combination with tensiometry and atomic force microscopy to study plasma proteins at the AWI alone and under the effect of synthetic polymers. First, the morphology of serum albumin layer controlled by the solution conditions was explored by fluorescence microscopy. Heterogeneity at the micron scale was observed for the protein film during adsorption and at educedr concentrations. Moreover, the competition for interfacial area between Pluronic surfactant F-127 and fibrinogen or serum albumin was studied by semi-quantitative confocal fluorescence methods. A transition stage where F-127 and protein underwent lateral phase separation was found. Two competing processes were revealed--the disintegration of protein-rich phase by F-127 and the coalescence of protein phase. Lastly, the interaction of immunoglobulin and the thin film of a widely used polydimethylsiloxane synthetic polymer was studied at the AWI. The compression state of the polymer film was shown ot significantly affect protein adsorption and guide proteins into circular domain structures. Overall, this work has demonstrated the wide utility of fluorescence microscopy to study protein-protein and protein- synthetic polymer interactions at the AWI. Degree Type Dissertation Degree Name Doctor of Philosophy (PhD) Graduate Group Chemistry First Advisor Ivan J. Dmochowski Keywords Air-water interface, Confocal microscopy, Plasma protein, Polymer, Self-assembly Subject Categories Chemistry | Physical Chemistry This dissertation is available at ScholarlyCommons: https://repository.upenn.edu/edissertations/774 PLASMA PROTEINS AND THEIR INTERACTION WITH SYNTHETIC POLYMERS AT THE AIR-WATER INTERFACE Zhengzheng Liao A DISSERTATION in Chemistry Presented to the Faculties of the University of Pennsylvania in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy 2013 Supervisor of Dissertation ________________________ Dr. Ivan J. Dmochowski, Associate Professor of Chemistry Graduate Group Chairperson _________________________ Dr. Gary A. Molander, Professor of Chemistry Dissertation Committee Dr. Feng Gai, Professor of Chemistry Dr. Tobias Baumgart, Associate Professor of Chemistry Dr. Barry Cooperman, Professor of Chemistry Dedicated to my Grandpa Mr. Junchang Liao 1931-2010 who will always be an inspiration in my life ii ACKNOWLEDGEMENT First of all, I would like to thank my advisor Prof. Ivan Dmochowski for his guidance and support throughout my grad career. I joined Prof. Dmochowski’s group as a fresh college graduate with limited experience in research, and Prof. Dmochowski was always encouraging whenever I showed him data or presented him a paper that I found interesting. His encouragement has been a motivation for me to continue the exploration in the ups and downs in my research. Under his influence, I had the opportunity to be exposed to different scientific fields and had collaborations with many people from diverse backgrounds, which greatly expanded my horizon and sharpened my skills. Furthermore, I want to express my appreciation to my thesis committee members-- Prof. Feng Gai, Prof. Tobias Baumgart and Prof. Barry Cooperman. They generously provided advice and criticism of my work, which prompted me to be a better researcher. I’m especially thankful to Prof. Baumgart, with whom I collaborated for the PDMS/protein and the SH3/PRM project. His great prudence and dedication to science have taught me much through the collaboration. Moreover, I would like to express my gratitude to Prof. David Eckmann, Prof. Portonovo Ayyaswamy, Prof. Roderic Eckenhoff and Prof. Daniel Hammer for the guidance on my other collaborative projects. I’m also grateful to Prof. Zahra Fakhraai, who was generous with her time in discussing ellipsometry. It has been an honor to work with so many great scholars and to absorb the knowledge from them. iii I have worked with many graduate students and postdocs at Penn, and I thank them all sincerely. I am sorry if I miss any names in the following list. Dr. Joshua Lampe from Prof. Eckmann’s lab was my first lab mentor and passed the torch of the air-water interface project to me. Dr. Xinjing Tang taught me many important experimental techniques including confocal microscopy, which became perhaps the most important part of my skill sets. Dr. Neha Kamat was a talented researcher from whom I learned a lot and with whom I absolutely enjoyed working. Dr. Ashley Fiamengo, Daniel Emerson, John Psonis, Breanna Caltagarone and James Hui collaborated with me on the interesting and challenging fluorescent anesthetic project. Thanks to their intellectual contributions, I have learned much more about the mechanism of anesthetics than I knew five years ago. Dr. Wan-Ting Hsieh is one of my best friends and worked closely with me on both the PDMS/protein project and SH3/PRM project. I learned from her the hardworking attitude and precious patience in doing research. Dr. Brittani Ruble and Sean Yeldell brought me into the TIVA-folate project in my last few months, which further enriched my research experience. Besides, a lot of people have helped me in research through many ways; I want to thank Yu-Hsiu Wang, Dr. Xi-Jun Chen, Helen Cativo, Zhaoxia Qian, Ethan Glor for their assistance in my experiments, and the staff of the Chemistry dDepartment for their support. Also, I would like to thank all the past and present members of the Dmochowski group. It has been a pleasure to be labmates with them. I am grateful to all my friends at Penn, without whom I would have never made it this far. During grad school, I was extremely lucky to get to know a lot of friends. I know that by mentioning some names I will likely miss some. Nevertheless, I want to particularly iv thank Jasmina Cheung-Lau, Chih-Jung Hsu, Xiaojing Liu, Wan-Ting Hsieh, Yu-Hsiu Wang, Keymo Chen, Claire Hsieh, Tingting Wu, Zheng Shi, Chun-Wei Lin, Jin Park, Min Pan, Yi-Ru Chen and Yi-Chi Lin. These people are not only my friends who I grow and learn with, but also essentially my family here in Philadelphia who generously have provided me company and support throughout the years. I also want to thank Zi Liang and Na Liu, who are always willing to lend an ear or travel hundreds of miles for me. We have been as close as sisters for about ten years and they are also part of my family in the U.S. Finally, I would like to thank my family. My grandma’s optimism and resilience after the passing of my grandpa has inspired me to be persistent in my pursuit. My parents, Zhonghong Liao and Huagui Zhang, are my ultimate support both financially and emotionally. They have given me unconditional love and trust, so that I can always find strength in adversity when I think of them. With that strength, I will continue on the journey following my heart and dreams. v ABSTRACT PLASMA PROTEINS AND THEIR INTERACTION WITH SYNTHETIC POLYMERS AT THE AIR-WATER INTERFACE Zhengzheng Liao Dr. Ivan J. Dmochowski The adsorption of proteins and synthetic polymers at the air-water interface (AWI) has broad significance in biomedicine and biotechnology. Protein behavior at the AWI can be guided to control the structure of the two-dimensional biopolymer film. In addition, synthetic polymers affect how plasma proteins act on implant or drug carrier surfaces, and can also decrease the potential for gas embolism. In this thesis, fluorescence microscopy was applied in combination with tensiometry and atomic force microscopy to study plasma proteins at the AWI alone and under the effect of synthetic polymers. First, the morphology of serum albumin layer controlled by the solution conditions was explored by fluorescence microscopy. Heterogeneity at the micron scale was observed for the protein film during adsorption and at reduced concentrations. Moreover, the competition for interfacial area between Pluronic surfactant F-127 and fibrinogen or serum albumin was studied by semi-quantitative confocal fluorescence methods. A transition stage where F-127 and protein underwent lateral phase separation was found. Two competing processes were revealed—the disintegration of protein-rich phase by F- 127 and the coalescence of protein phase. Lastly, the interaction of immunoglobulin and the thin film of a widely used polydimethylsiloxane synthetic polymer

Load more