Gong, Xiangjun = 新型全內反射顯微鏡的搭建及其在膠體研究中的應用 / 龔湘君. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Abstracts in English and Chinese. / Gong, Xiangjun = Xin xing quan nei fan she xian wei jing de da jian ji qi zai jiao ti yan jiu zhong de ying yong / Gong Xiangjun. / Abstract (Chinese) --- p.i / Abstract --- p.iii / Contents --- p.v / Acknowledgement --- p.vii / Chapter Chapter 1 --- Introduction to Total Internal Reflection Microscopy (TIRM) / Chapter 1.1 --- History of TIRM --- p.1 / Chapter 1.2 --- Instrumentation --- p.1 / Chapter 1.2.1 --- Apparatus --- p.1 / Chapter 1.2.2 --- Optical Tweezer --- p.3 / Chapter 1.3 --- The principle of the technique --- p.5 / Chapter 1.3.1 --- Total Internal Reflection --- p.5 / Chapter 1.3.2 --- Details on Scattering of the Evanescent Wave --- p.7 / Chapter 1.3.3 --- Data analysis --- p.14 / Chapter 1.3.4 --- A typical potential energy profile --- p.17 / Chapter 1.4 --- Noise Analysis and Removal Method --- p.19 / Chapter 1.4.1 --- Noise analysis --- p.19 / Chapter 1.4.2 --- Noise removal: low-pass filtering --- p.22 / Chapter 1.5 --- Other techniques on force measurement --- p.25 / Chapter 1.6 --- References --- p.27 / Chapter Chapter 2 --- Experiments on TIRM Calibration / Chapter 2.1 --- Introduction --- p.30 / Chapter 2.2 --- Pre-Experimental Section --- p.30 / Chapter 2.2.1 --- Glass Surface Preparation Methods --- p.30 / Chapter 2.2.2 --- Experimental Setup --- p.33 / Chapter 2.3 --- Calibration Results and Discussion --- p.36 / Chapter 2.4 --- Conclusions --- p.42 / Chapter 2.5 --- References --- p.43 / Chapter Chapter 3 --- TIRM investigation on polymer-induced collodial interactions / Chapter 3.1 --- Introduction to polymer-induced forces --- p.45 / Chapter 3.1.1 --- Non-absorbing case - depletion force --- p.46 / Chapter 3.1.2 --- Attached polymer layers --- p.49 / Chapter 3.2 --- Applications of TIRM in polymer-mediated colloidal interactions --- p.54 / Chapter 3.2.1 --- Measurements on depletion force --- p.54 / Chapter 3.2.2 --- Measurements on Steric Forces --- p.56 / Chapter 3.3 --- Direct measurement of thermosensitive Poly(N-isopropylacrylamide)-mediated colloidal interactions with TIRM --- p.56 / Chapter 3.3.1 --- Introduction --- p.56 / Chapter 3.3.2 --- Experimental Section --- p.57 / Chapter 3.3.3 --- Results and Discussion --- p.60 / Chapter 3.3.4 --- Conclusions --- p.73 / Chapter 3.4 --- References --- p.74 / Publication List --- p.77

Indiana University-Purdue University Indianapolis (IUPUI) / Hydrogels prepared from photopolymerization have been widely used in many biomedical applications. Ultraviolet (200-400 nm) or visible (400-800 nm) light can interact with light-sensitive compounds called photoinitiators to form radical species that trigger photopolylmerization. Since UV light has potential to cause cell damage, visible light-mediated photopolymerization has attracted much attention. The conventional method to fabricate hydrogels under visible light exposure requires usage of co-initiator triethanolamine (TEA) at high concentration (∼200 mM), which reduces cell viability. Therefore, the first objective of this thesis was to develop a new method to form poly(ethylene glycol)-diacrylate (PEGDA) hydrogel without using TEA. Specifically, thiol-containing molecules (e.g. dithiothreitol or cysteine-containing peptides) were used to replace TEA as both co-initiator and crosslinker. Co-monomer 1-vinyl-2-pyrrolidinone (NVP) was used to accelerate gelation kinetics. The gelation rate could be tuned by changing the concentration of eosinY or NVP. Variation of thiol concentration affected degradation rate of hydrogels. Many bioactive motifs have been immobilized into hydrogels to enhance cell attachment and adhesion in previous studies. In this thesis, pendant peptide RGDS was incorporated via two methods with high incorporation efficiency. The stiffness of hydrogels decreased when incorporating RGDS. The second objective of this thesis was to fabricate hydrogels using poly(ethylene glycol)-tetra-acrylate (PEG4A) macromer instead of PEGDA via the same step-and-chain-growth mixed mode mechanism. Formation of hydrogels using PEGDA in this thesis required high concentration of macromer (∼10 wt.%). Since PEG4A had two more functional acrylate groups than PEGDA, hydrogels could be fabricated using lower concentration of PEG4A (∼4 wt.%). The effects of NVP concentration and thiol content on hydrogel properties were similar to those on PEGDA hydrogels. In addition, the functionality and chemistry of thiol could also affect hydrogel properties.