本論文論述了一系列包含疏水性樹枝狀烷烴基團的兩親性分子的合成和表徵、在水溶液中的自組裝性質及其對小分子客體的增溶能力的研究。第一部分為第一至第三代兩親性“樹枝直鏈雜化物“[Gn]-OEG₈ 128-130, 該類雜化物含有的樹枝狀烷烴基團以醯胺鍵在其核心連接親水性八聚乙二醇基團。這些兩親性分子在水溶液中自組裝形成膠束結構。此外我們還製備了烷烴雙鏈[Dn]-OEG₈及烷烴單鏈[Ln]-OEG₈同分異構體，並研究其疏水基團的支化程度對自組裝性質的影響。第二部分,我們通過銅()催化-疊氮-端基炔的環加成反應（CuAAC）對第〇代至第二代樹枝狀烷烴聚合物OEG-[Gn]-dendrimer 171-173進行表面修飾，製備了具有親水性四聚乙二醇外殼的樹枝狀兩親性分子，並研究其疏水基團大小對自組裝性質及對小分子客體增溶能力的影響。 / 所有化合物的結構均通過核磁共振氫譜、碳譜、質譜和凝膠排阻色譜進行表徵。其自組裝性質如臨界膠束/聚集濃度（CMC/CAC）、微環境極性、粒子尺寸分佈和藥物承載能力的大小則通過熒光光譜、紫外可見光譜和光散射等方法進行研究。實驗結果表明：（一）臨界膠束/聚集濃度隨著疏水基團的增大而減小；（二）臨界膠束/聚集濃度隨著疏水基團的支化程度的提高而增加（即直鏈<雙鏈<樹枝狀）；（三）支化程度較高的兩親性分子會形成較為鬆散的膠束結構，其核心的極性也會相應提高；（四）膠束核心的極性隨著樹枝狀聚合物的代數增加而降低。這些結論均與疏水烷烴基團的尺寸（即長度或代數）及結構（即支化程度）相關聯，並與文獻中的計算擬合結果相符。 / 同時本工作也發現了一些與文獻的擬合結果不吻合的實驗結果：（一）由於長鏈烷烴的自卷現象，烷烴單鏈[L2]-OEG₈比其雙鏈[D2]-OEG₈異構體具有更高的臨界膠束濃度；（二）基於光散射實驗結果，具有“單分子膠束“結構的樹枝狀烷烴聚合物OEG-[Gn]-dendrimer 171-173能夠形成大型膠束聚集體；（三）這些樹枝狀烷烴聚合物的增溶能力與其疏水內核的大小並不相關。後兩個結果反映出由於大型兩親性分子具有多種自組裝方式，其膠束性質及增溶能力具有相當的複雜性和不確定性。 / 在此之前，相關研究工作主要集中在理論計算和電腦模擬部分，本論文首次以實驗手段研究具有不同支化程度的疏水樹枝狀烷烴基團的兩親性分子及其自組裝性質。我們的大部分結果證實了文獻報導的結論，並指出了一些模擬計算忽略的問題，為以後的相關工作提供重要的數據支援。 / This thesis described the synthesis, self-assembling and/or encapsulation properties of two different classes of amphiphilic dendritic compounds. The first set of amphiphilic dendrons [Gn]-OEG₈ 128-130 (n = 1-3) are dendritic-linear hybrid molecules that have a hydrophobic hydrocarbon (HC) dendron connected to a hydrophilic octa(ethylene glycol) chain. The effect of the branching architecture on their self-assembling properties was then compared to that of their doubly branched [Dn]-OEG₈ and linear [Ln]-OEG₈ analogs, which were also prepared in this study. The second set of compounds are a series of amphiphilic dendrimers OEG-[Gn]-dendrimer 171-173 (n = 0-2) decorated with surface tetra(ethylene glycol) chains on the periphery of a HC dendrimer. The size effect of the HC sector on their self-assembling and drug encapsulation properties with indomethacin was examined. / The structures of all compounds were characterized by ¹H and ¹³C NMR spectroscopy, mass spectrometry, and gel permeation chromatography. Their self-assembling and host-guest complexation properties, such as critical micellar/association concentrations (CMC/CAC), micro-environmental polarity, particle size distributions and drug loading capacity were investigated by various physical techniques such as UV and fluorescent spectroscopy, as well as static and dynamic laser light scattering. Based on our experimental findings, we were able to confirm the results obtained from earlier theoretical simulations. First, for both series of dendritic amphiphiles, their CMC/CAC values decreased with increasing size of the hydrophobic segment. Second, with the same molecular formula and hydrophobic/lipophilic balance (HLB), amphiphiles containing a hydrophobic segment of a higher branching degree possessed a higher CMC/CAC value. Third, the micellar core of amphiphiles with a dendritic hydrophobic sector was more polar than that of non-dendritic amphiphiles having the same molecular formula. Fourth, the micellar core of a dendritic amphiphile of a higher generation was more non-polar than that of the lower generation analogues. All the findings could be correlated to the size (i.e. length or generation) and the architecture (i.e. branching pattern) of the hydrophobic HC sector. / Three unusual findings that deviated from previous theoretical simulations were noted. First, the doubly branched [D2]-OEG₈ 132 was found to have a lower CMC value than the linear [L2]-OEG₈ 134. This anomaly could be rectified if backfolding of the linear HC chain is taken into consideration. Second, based on DLS study, it was noted that the ‘unimolecular’ OEG-[Gn]-dendrimers 171-173 were capable of forming ‘giant’ aggregates in aqueous solutions. Third, their drug loading capacity did not correlate to the size of the hydrophobic HC sector. The latter two findings revealed the complexity in dealing with the understanding of the self assembling and host-guest complexation processes of these large amphiphile dendrimers. Prior to our work, only theoretical calculations had been carried out. The work described in this thesis serves to provide solid experimental evidence in support of the theoretical simulations and offer additional insights that were previously neglected in this subject area. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Liang, Yuting. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 149-156). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / Contents --- p.i / Acknowledgments --- p.vi / Abstract --- p.vii / Abbreviations --- p.xi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- General --- p.1 / Chapter 1.2 --- Construction of Dendrimers --- p.2 / Chapter 1.2.1 --- The Divergent Approach --- p.2 / Chapter 1.2.2 --- Convergent Approach --- p.3 / Chapter 1.2.3 --- Modification --- p.4 / Chapter 1.2.3.1 --- Modification at the Focal Point --- p.5 / Chapter 1.2.3.2 --- Modification on the Periphery --- p.6 / Chapter 1.2.4 --- CuAAC ‘Click’ Reaction in Dendrimer Synthesis --- p.8 / Chapter 1.3 --- Physical Properties of Dendrimers --- p.13 / Chapter 1.3.1 --- Location of End Groups --- p.13 / Chapter 1.3.2 --- Comparison of Dendritic -- Linear Analogs --- p.15 / Chapter 1.3.3 --- Generation Dependence -- Dendritic Effect --- p.16 / Chapter 1.4 --- Dendritic Amphiphiles --- p.18 / Chapter 1.4.1 --- Amphiphiles and their aggregations --- p.18 / Chapter 1.4.2 --- Dendritic Amphiphiles --- p.20 / Chapter 1.4.2.1 --- Unimolecular Micelles --- p.20 / Chapter 1.4.2.2 --- Bolaamphiphiles --- p.22 / Chapter 1.4.2.3 --- Amphiphilic dendritic-linear polymer hybrids --- p.23 / Chapter 1.4.2.4 --- Facially amphiphilic dendrimers --- p.25 / Chapter 1.5 --- Applications of Dendritic Amphiphiles --- p.27 / Chapter 1.5.1 --- Drug Delivery --- p.27 / Chapter 1.5.1.1 --- Encapsulation via Non-Covalent Interactions --- p.27 / Chapter 1.5.1.2 --- Covalent Bonded Dendrimer -- Drug Conjugates --- p.29 / Chapter 1.5.2 --- Biomimetics --- p.30 / Chapter Chapter 2 --- Architecture and Generation Effects on the Self-Assembly of Amphiphilic Dendritic-Linear Polymer Hybrids --- p.33 / Chapter 2.1 --- Packing Parameters --- p.33 / Chapter 2.2 --- Computer Simulations --- p.35 / Chapter 2.3 --- Experimental studies --- p.38 / Chapter 2.4 --- Methods --- p.40 / Chapter 2.4.1 --- Fluorescence Studies --- p.41 / Chapter 2.4.2 --- Laser Light Scattering --- p.42 / Chapter 2.4.3 --- Electron Microscopy --- p.42 / Chapter 2.5 --- Research Objectives --- p.43 / Chapter Chapter 3 --- Design, Synthesis and Characterization of Novel Amphiphilic Dendritic-Linear Polymer Hybrids --- p.44 / Chapter 3.1 --- Design --- p.45 / Chapter 3.1.1 --- Dendritic-Linear Polymer Hybrids: Hydrocarbon Dendrons (Gn) and Their Linear (Ln) and Doubly Branched (Dn) Analogs --- p.45 / Chapter 3.1.2 --- Selection of Hydrophilic Block: Oligo(Ethylene Glycol) Chains --- p.47 / Chapter 3.2 --- Synthesis --- p.48 / Chapter 3.2.1 --- Preparation of Amino- and Azido- Functionalized Oligoethylene Glycols --- p.48 / Chapter 3.2.2 --- Preparation of [Gn]-COOH, [Dn]-COOH and [Ln]-COOH --- p.49 / Chapter 3.2.3 --- Preparation of [Gn]-OEG₈, [Dn]-OEG₈ and [Ln]-OEG₈ --- p.52 / Chapter 3.3 --- Characterization --- p.53 / Chapter 3.3.1 --- ¹H NMR Spectroscopy --- p.53 / Chapter 3.3.2 --- ¹³3C NMR spectroscopy --- p.55 / Chapter 3.3.3 --- Mass Spectrometry --- p.56 / Chapter 3.3.4 --- Gel Permeation Chromatography --- p.57 / Chapter 3.3.5 --- Physical Appearance and Melting Point --- p.59 / Chapter 3.4 --- Self-assembly Behavior of [Gn]-OEG₈, [Dn]-OEG₈ and [Ln]-OEG₈ in Water --- p.60 / Chapter 3.4.1 --- Critical Micellar Concentration (CMC) --- p.60 / Chapter 3.4.1.1 --- Effect of the size of hydrophobic sector --- p.63 / Chapter 3.4.1.2 --- Effect of Branching on Micelle Formation --- p.64 / Chapter 3.4.2 --- Microenvironment Polarity inside the Micelles --- p.67 / Chapter 3.4.3 --- Hydrodynamic Radius (R[subscript h]) --- p.71 / Chapter 3.5 --- Summary --- p.73 / Chapter Chapter 4 --- Amphiphilic Unimolecular Micelles: Multiple Surface Functionalized Hydrocarbon-Based Dendrimers --- p.75 / Chapter 4.1 --- Design --- p.75 / Chapter 4.1.1 --- The Surface Acetonide-Protected Hydrocarbon Dendrons --- p.76 / Chapter 4.1.2 --- Peripheral Post-Modification via CuAAC ‘click’ chemistry --- p.77 / Chapter 4.2 --- Synthesis --- p.78 / Chapter 4.2.1 --- Preparation of Amphiphilic HC Dendrimers with a Peripheral Acetylene Layer --- p.78 / Chapter 4.2.1.1 --- Preparation of Amphiphilic Dendrimers via CuAAC ‘click’ reaction --- p.83 / Chapter 4.3 --- Characterization --- p.85 / Chapter 4.3.1 --- ¹H NMR Spectroscopy --- p.85 / Chapter 4.3.1.1 --- Dendrons/Dendrimers with Acetonide-Protected or Polyol Surface --- p.86 / Chapter 4.3.1.2 --- Dendrons/Dendrimers with Multiple Acetylene Functionalized Surface --- p.87 / Chapter 4.3.1.3 --- Amphiphilic Dendrimers with Triazolo OEG Surface --- p.89 / Chapter 4.3.2 --- ¹³C NMR spectroscopy --- p.90 / Chapter 4.3.2.1 --- Dendrons/Dendrimers with Acetonide-Protected or Polyol Surface --- p.90 / Chapter 4.3.2.2 --- Dendrons/Dendrimers with Multiple Acetylene Surface --- p.91 / Chapter 4.3.2.3 --- Amphiphilic Dendrimers with Triazolo OEG Surface Groups --- p.93 / Chapter 4.3.3 --- Mass Spectrometry --- p.94 / Chapter 4.3.4 --- Gel Permeation Chromatography --- p.98 / Chapter 4.4 --- Micellar Properties of Amphiphilic OEG-[Gn]-Dendrimers 171-173 --- p.101 / Chapter 4.4.1 --- Critical Micellar Concentration (CMC) --- p.101 / Chapter 4.4.2 --- Particle Size Distribution and Aggregation Number --- p.105 / Chapter 4.5 --- Encapsulation with Hydrophobic Guest Molecule -- Indomethacin --- p.107 / Chapter 4.5.1 --- Hydrodynamic Radius of IMC Loaded Particles --- p.107 / Chapter 4.5.2 --- Loading Efficiency --- p.109 / Chapter 4.5.2.1 --- Effect of Amphiphile Concentration on Loading Efficiency --- p.109 / Chapter 4.5.3 --- Release Profile --- p.113 / Chapter 4.6 --- Summary --- p.113 / Chapter Chapter 5 --- Conclusions --- p.115 / Chapter Chapter 6 --- Experimental --- p.117 / Chapter 6.1 --- General Methods --- p.117 / Chapter 6.2 --- Synthesis --- p.118 / Chapter 6.3 --- Characterization of Micellar Properties --- p.143 / Chapter 6.3.1 --- Preparation of Micellar Solutions --- p.143 / Chapter 6.3.2 --- Preparation of Pyrene Loaded Samples --- p.143 / Chapter 6.3.3 --- Determination of CMCs from Fluorescence Probe Method --- p.143 / Chapter 6.3.4 --- Laser Light Scattering --- p.146 / Chapter 6.3.5 --- Transmission Electron Microscopy --- p.147 / Chapter 6.4 --- Drug Encapsulation and Release Study --- p.147 / Chapter 6.4.1 --- Preparation of Indomethacin (IMC) Loaded Samples --- p.147 / Chapter 6.4.2 --- Determination of IMC Loading Amount --- p.147 / Chapter 6.4.3 --- In vitro Drug Release Profile --- p.148 / Reference --- p.149 / Chapter Appendix --- List of Spectra --- p.Ai
| Identifer | oai:union.ndltd.org:cuhk.edu.hk/oai:cuhk-dr:cuhk_328024 |
| Date | January 2012 |
| Contributors | Liang, Yuting., Chinese University of Hong Kong Graduate School. Division of Chemistry. |
| Source Sets | The Chinese University of Hong Kong |
| Language | English, Chinese |
| Detected Language | English |
| Type | Text, bibliography |
| Format | electronic resource, electronic resource, remote, 1 online resource (xi, 156, Aiii, A76 leaves) : ill. (some col.) |
| Rights | Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/) |
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