Abbreviations ................................................ I
Nomenclature of Polymers and Dendritic Architectures ........ IV
1 General Introduction ......................................... 1
1.1 Concept of Nanoscale Drug Delivery System (Nano-DDS) .... 1
1.2 Modes/Mechanism of Drug Delivery from Nano-DDS: State-
of-the-Art .............................................. 2
1.2.1 Supramolecular Drug-Polymer Complex .............. 3
1.2.2 Drug-Polymer Conjugates: The Covalent Approach ... 6
1.3 Specialized Polymers as Nano-DDS: Dendrimers ............ 8
1.4 Hyperbranched Polymers for Nano-DDS Application ........ 11
1.5 Hyperbranched Polyglycerol as Drug Delivery Platform ... 14
1.5.1 Synthesis of Well-defined Hyperbranched
Polyglycerol .................................... 16
1.5.2 Core Variation and Diversification of
Polyglycerol Scaffold ........................... 17
1.5.3 Biocompatibility Profile of Dendritic
Polyglycerols ................................... 18
1.5.4 Biomedical Applications of Hyperbranched
Polyglycerol .................................... 19
2 Objective of the Thesis ..................................... 24
3 Polyglycerol based Multivalent Ligand for Copper Ion
Transport ................................................... 26
3.1 Copper in Physiology: Role, Deficiency Disorders and
Homeostasis ............................................ 26
3.2 Objective of the Project ............................... 29
3.3 The Blood-brain Barrier (BBB) and Transporter Design ... 30
3.4 Synthesis of Polyglycerol Based Nanocarriers for Cu
Ion Transport .......................................... 31
3.4.1 Synthesis of Dialkylamine Functionalized
Polyglycerol .................................... 32
3.4.2 Synthesis of Core-aminated Polyglycerol ......... 34
3.4.3 Synthesis of Polyglycerol-bispicolylamide
Derivatives ..................................... 36
3.4.4 Synthesis of Mono- and Oligosaccharide
Modified Polyglycerolamine ...................... 39
3.4.5 Attaching N-α-BOC-Histidine to
Polyglycerolamine: BBB Targeted Nanocarriers .... 40
3.4.6 Immobilizing Ascorbic Acid onto Polyglycerol .... 41
3.4.7 Synthesis of FTTC-Labeled PG10-TMEDA System ..... 43
3.5 Proof of Cu-encapsulation by Synthesized Constructs:
UV-Vis Spectroscopy .................................... 43
3.6 Energetics of Cu-ion encapsulation: Isothermal
Titration Calorimetry (ITC) ............................ 47
3.7 Surface Charge Determination ........................... 51
3.8 Interaction of Cu-ion Encapsulating Systems with
Plasma Albumin ......................................... 54
3.9 Cellular Toxicity of the Synthesized Architectures ..... 57
3.10 Uptake of PG10-TMEDA system by Living Cells ............ 58
3.11 Discussion ............................................. 60
4 Core Single-shell and Core-multishell Architecture for
Cellular Delivery of Copper Ions ............................ 64
4.1 Introduction ........................................... 64
4.2 Objective of the project ............................... 65
4.3 Synthesis of CS NPs and CMS NPs ........................ 65
4.4 Fluorescent Labelling and Biochemical Experiments ...... 66
4.5 In Vitro Encapsulation and Cellular Delivery Cu-ion
by CS and CMS NPs ...................................... 67
4.5.1 Evidence and Stoichiometry of Encapsulation:
UV-Vis Spectroscopy ............................. 67
4.5.2 Thermodynamics of Encapsulation: Isothermal
Titration Calorimetry .......................... 68
4.5.3 Spontaneous Encapsulation of Cu by the
Nanocarriers in Cellular Environment ............ 68
4.5.4 Accessibility of Carrier Cargo .................. 70
4.5.5 Toxicity of Nanocarriers in Higher Eukaryotic
Cells ........................................... 71
4.5.6 Cellular Cu Localization, Possible Targets and
Effect on Aß Production ......................... 72
4.5.7 Endocytosis of CMS NPs and CS NPs ............... 75
4.6 Discussion ............................................. 77
5 Non-covalent Encapsulation of Drugs in Dendritic Polymers ... 80
5.1 Introduction ........................................... 80
5.2 Objective of the Project ............................... 81
5.3 Interaction between Representative Dendritic Polymers
and Model Drugs ........................................ 82
5.3.1 Model 1. Interaction between Ibandronate and
Core-mutishell Nanoparticles .................... 82
5.3.2 Model 2. Interaction of ATP with
Oligosaccharide Modified Hyperbranched PEI ...... 84
5.4 Calorimetric Protocol for the Model Interactions ....... 87
5.5 Results and Discussion of Interaction Experiments ...... 87
5.5.1 Ibn Encapsulation by CMS NPs .................... 87
5.5.2 ATP Encapsulation by Oligosaccharide-modified
Hyperbranched PEI ............................... 90
6 Conjugation of Drugs to Hyperbranched Polyglycerol:
Covalent Approach ........................................... 97
6.1 Covalent Conjugation of Morphine onto Polyglycerol ..... 97
6.1.1 Chemistry and Pharmacology of Morphine .......... 97
6.1.2 Objective of the Project ........................ 98
6.1.3 Reported Synthetic Strategies to Design
Morphine Prodrugs/Delivery System .............. 100
6.1.4 Esterification of Morphine with Polyglycerol
Carboxylate .................................... 101
6.1.5 Amidation of Succinylated Morphine to
Polyglycerolamine .............................. 104
6.1.6 Biological Investigation in Rat Model .......... 106
6.2 Attachment of Coumarin onto Polyglycerol
Architecture .......................................... 109
6.2.1 Attachment of Coumarin to Succinylated
Polyglycerol ................................... 110
6.2.2 The "Click" Approach to Immobilize Coumarin
onto Polyglycerol Backbone ..................... 111
6.2.3 Photoactivity of 4-methyl 7-hydroxy Coumarin
Loaded Polyglycerol ............................ 113
6.3 Discussion ............................................ 116
7 Summary and Conclusion ..................................... 118
8 Outlook .................................................... 121
9 Experimental Part .......................................... 122
9.1 Materials ............................................. 122
9.1.1 Polymers ....................................... 122
9.1.2 Chemicals ...................................... 122
9.2 Analytical Methods .................................... 122
9.2.1 NMR Spectroscopy ............................... 122
9.2.2 Dialysis ....................................... 122
9.2.3 Size Exclusion Chromatography (SEC) ............ 123
9.2.4 TLC and Dry Flash Column Chromatography ........ 123
9.2.5 UV-Vis Spectrosocpy ............................ 123
9.2.6 Isothermal Titration Calorimetry (ГТС) ......... 123
9.2.7 Zeta Potential Measurement ..................... 124
9.2.8 Fluorescence Spectroscopy ...................... 124
9.3 Synthesis of Selected Polyglycerol Analogues and
Intermediates ......................................... 125
10 References ................................................. 145
11 Zusammenfassung ............................................ 156
12 Appendix ................................................... 158
Curriculum Vitae ........................................... 159
List of publications ....................................... 160
Poster presentations ....................................... 160
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