Degradable low-fouling hydrogels are ideal vehicles for drug and cell delivery. For each application, hydrogel degradation rate must be re-optimized for maximum therapeutic benefit. We developed a method to rapidly tune degradation rates of low-fouling poly(oligo(ethylene glycol) methyl ether methacrylate) (P(EG)xMA) hydrogels by modifying two interdependent variables: (1) base-catalyzed crosslink degradation kinetics, dependent on crosslinker electronics (electron withdrawing groups (EWGs)); and (2) polymer hydration, dependent on the molecular weight (MW) of poly(ethylene glycol) (PEG) pendant groups. By controlling EWG strength and PEG pendant group MW, P(EG)xMA hydrogels were tuned to degrade over 6 to 52 d. A six-member P(EG)xMA copolymer library yielded slow and fast degrading low-fouling hydrogels for short- and long-term delivery applications. The degradation mechanism was also applied to RGD-functionalized poly(carboxybetaine methacrylamide) (PCBMAA) hydrogels to achieve slow (52 d) and fast (13 d) degrading low-fouling, bioactive hydrogels. / Thesis / Master of Science (MSc) / The delivery of drugs and cells to disease sites is hindered by transport barriers, which can be overcome through local delivery. Injectable hydrogels can serve as local depots that release drugs or cells to improve therapeutic benefit. Currently, however, hydrogels suffer from uncontrolled degradation in the body, degrading at unpredictable rates dependent on the local environment; hydrogels with predictable and tunable degradation rates are therefore required. Herein, we report a method to produce a library of polymers that in situ crosslink to form hydrogels with a range of degradation rates only influenced by the local environments pH, a known quantity. Moreover, the polymers are low-fouling and therefore have minimal non-specific interactions with biomolecules and cells, which improves biocompatibility.

Le principal but de cette thèse a été d'étudier l'organisation structurale et les propriétés électroniques d'une nouvelle famille de conducteurs à base de poly(aniline) obtenus par protonation de sa forme éméraldine base par des acides n-alcanesulfoniques. Pour faciliter l'interprétation des données expérimentales de nature relativement complexe, des études parallèles ont été menées sur la tétra(aniline) dopée-le plus petit composé modèle de l'unité de répétition de la poly(aniline). Les tétra- et poly(aniline) dopées peuvent être considérées comme des architectures auto-assemblées par interactions ioniques qui présentent un comportement cristal liquide thermotrope comme le montrent les expériences complémentaires de diffraction des Rayons X et de calorimétrie différentielle à balayage. Ces conducteurs organiques présentent une structure lamellaire dont les caractéristiques peuvent être ajustées par des traitements thermiques, la longueur de la chaine alcane du dopant et dans le cas des films minces, par le nature du substrat. La conductivité électronique des films auto-supportés de PANI[acides n-alcanesulfonique]0.5 est élevée (~100-200 S.cm-1), et la dépendance thermique de la conductivité est interprétée dans le cadre du modèle dit de "désordre hétérogène" qui prend en compte une contribution semi-conductrice et une contribution métallique. Les mesures de conductivité associées à une séquence de recuits peuvent être considérées comme une mise en évidence indirecte des transitions de phase dans ces nouveaux conducteurs organiques et montrent clairement une évolution vers un comportement commun à toute la famille étudiée.

Interferons (IFNs) are a class of structurally related proteins first discovered to be produced by virus-infected cells. By now, several other inducing agents have been described. IFNs exert multiple effects on cells exemplified by the establishment of an antiviral state, inhibition of cell proliferation and alteration of different immune reactions. In the present thesis the inhibition of cellular growth concentrated on effects in the early cell cycle have been studied. The human glioma cell line 251 MG was found to be blocked in the S phase of the cell cycle upon addition of IFN both to exponentially growing and growth-factor depleted, synchronized cells. Thymidine kinase and DNA-polymerase activities were reduced in parallel with the S phase effect. 2-5 oligo Anucleotides transfected into glioma cells lead to inhibition of cell growth, exponentially growing cells being blocked in the S phase as during IFN treatment. In contrast, synchronized, restimulated cells were blocked in the cellcycle phase where they resided at the time of transfection. As 2-5 oligo A synthetase activity was induced in the middle of the Gl phase, these results might indicate that the kinetics of expression of oligonucleotides after IFN additiondetermines the type of cell cycle block obtained in differenttumor cells. IFN inhibited preferentially proteins originating from newly synthesized mRNA in Sw 3T3 cells, c-mvc did not seem to be included among these proteins. In both cell systems c-myc expression was unaltered after IFN treatment. In clone T1 selected from the the Sw 3T3 cell line , c-mvc expression was uncoupled to growth and seemed to be growth factor independent. The change in c-myc expression in clone T1 compared to SW 3T3 cells did not render the cells sensitive to IFN. Hence, c-myc regulation does not seem to be the mechanism by which IFN regulates cell growth in this system. The proliferation marker KI-67 antigen was shown not to be causatively involved in growth inhibition of IFN. The reduced levels of the antigen was proposed to be a secondary effect caused by the G0/G1 arrest. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1991, härtill 6 uppsatser</p> / digitalisering@umu

Les nanogels hybrides constitués de polymères thermosensibles et de nanoparticules inorganiques stimulables telles que des nanoparticules magnétiques (NPMs) ou des nanobatônnets d’or (AuNRs) sont extrêmement intéressants pour des applications biomédicales. Leur matrice en polymère permet d’encapsuler et de libérer de grandes quantités de molécules actives, alors que les nanoparticules peuvent générer de la chaleur lorsqu’elles sont exposées à un champ magnétique alternatif (AMF) pour les NPMs, et à une irradiation proche infrarouge (NIR-L) pour les AuNRs. Ce manuscrit de thèse porte sur la synthèse et la caractérisation de nanogels biocompatibles, pH- et thermosensibles, à base de monomères en oligo (éthylène glycol) méthyl éther méthacrylate (OEGMAs), d’acide méthacrylique (MAA) et encapsulant des NPMs et/ou des AuNRs pour déclencher de manière contrôlée, par hyperthermie magnétique ou par photothermie, la libération d’une molécule anticancéreuse, la doxorubicine (DOX). Des nanogels hybrides magnétiques, plasmoniques et magnéto-plasmoniques ont été synthétisés. Ces nanogels ont un diamètre hydrodynamique entre 200 et 500 nm et une température de transition de phase volumique comprise entre 30 et 54 °C. Le comportement de gonflement-dégonflement des nanogels peut être induit par plusieurs stimuli (température, pH, AMF, NIR-L). Ces résultats démontrent que les MagNanoGels sont d’excellents nanovecteurs pour accroître l’internalisation cellulaire en augmentant la cytotoxicité de la DOX et qu’il est possible de déclencher à distance la libération intracellulaire de DOX sous AMF dans des conditions athermiques. Par ailleurs, les PlasMagNanoGels peuvent générer efficacement de la chaleur par photothermie pour une thermothérapie. En outre, les propriétés intrinsèques des NPMs, pour le ciblage magnétique et en tant qu’agents de contraste pour l’imagerie par résonance magnétique (MRI), font de ces nanogels des candidats idéaux pour une nouvelle approche thérapeutique (diagnostique et traitement) contre le cancer. / Hybrid nanogels, composed of thermoresponsive polymers and inorganic responsive nanoparticles, such as magnetic nanoparticles (NPMs) and gold nanorods (AuNRs) are highly interesting for biomedical applications. Their polymeric matrix makes them able to uptake and release high quantities of drugs, whereas nanoparticles can generate heat when exposed to an alternating magnetic field (AMF) for NPMs, and to a near-infrared light for AuNRs. This thesis manuscript focuses on the synthesis and the characterization of biocompatible, pH- and thermoresponsive nanogels, based on oligo(ethylene glycol) monomers (OEGMAs), methacrylic acid (MAA) and encapsulating NPMs and/or AuNR for remotely triggered doxorubicin (DOX, anticancer drug) release, by magnetic hyperthermia or phothothermia. Hybrid magnetic, plasmonic and magneto-plasmonic nanogels were synthesized. Theses nanogels have a hydrodynamic diameter between 200 and 500 nm and a volume phase transition temperature (VPTT) from 30 to 54°C. The nanogels’ swelling-deswelling behavior can be induced by several stimuli (temperature, pH, AMF, NIR-L). These results demonstrate that MagNanoGels are excellent nanocarriers for enhancing cellular internalization enhancing DOX cytotoxicity and that DOX release was significantly enhanced upon exposure to AMF in athermic conditions. In addition, PlasMagNanoGels can efficiently generate heat by photothermy for thermotherapy. Therefore, the intrinsic properties of NPMs for magnetic targeting and as contrast agents for Magnetic Resonance Imaging (MRI), make these nanogels ideal candidates for a new therapeutic approach (diagnosis and treatment) against cancer.

xiii, 198 p. : ill. (some col.) / Whether or not a causal relationship exists between climate and mammal body size is one of the longest-standing and most intractable questions in ecology. The classic model of body size evolution (Bergmann's Rule) holds that body size is driven by temperature, but more recent hypotheses have suggested that other climatic variables or biotic interactions may play a more important role. The use of paleoecological data to address this question allows variables that are tightly correlated in modern ecosystems to be teased apart and allows body size patterns to be observed through time, adding an extra dimension to analyses. This dissertation details the findings of two paleoecological tests of Bergmann's Rule in the Oligo-Miocene (30-5 Ma), one tracking body size and climate through time in the northwestern United States and another tracking geographic body size trends through time along the west coast of North America. In both cases, body size was analyzed in three representative families of mammals: equids, canids, and sciurids. Such large-scale analyses are dependent on fossils that can be placed in a reliable taxonomic, geologic, and temporal context, and this dissertation also focuses on a reevaluation of the canid fauna of Oregon's Juntura Formation that places a critically important Late Miocene carnivore fauna in just such a context. Two genera of canids - Epicyon and Carpocyon - are described from the fauna for the first time, with important implications for regional biostratigraphy. The body size analyses show no consistent relationship between body size and any climatic variable. Further, body size patterns vary widely between taxa at several levels, suggesting that one universal driver of body size evolution does not exist. Not only is there no evidence for Bergmann's Rule in Oligo-Miocene mammals, but comparative analyses of geographic body size patterns in the modern genera Odocoileus, Canis, and Spermophilus fail to show the latitudinal gradients upon which Bergmann's Rule is predicated. The apparent existence of such trends in some taxa may be the result of anthropogenic extirpation at low latitudes, further underscoring the importance of including paleontological data when formulating models predicting the response of biotic variables to environmental change. / Committee in charge: Dr. Samantha Hopkins， Chair； Dr. Gregory Retallack， Member； Dr. Rebecca Dorsey， Member； Dr. Stephen Frost， Outside Member

Le manuscrit est divisé en six chapitres et deux parties indépendantes, la première étant consacrée à l'étude de l'effet de substituants nitro sur des ligands phosphines aromatiques (L). Une série de (N-phényl-benzimidazol-1-yl)diphénylphosphines substituées par 1 à 3 groupes nitro à différentes positions des noyaux N-phényle et benzimidazolyle, a été synthétisée, et comparée au parent non nitré et à l'homologue N-méthyl-benzimidazolium cationique. Dans les complexes trans-L2RhICl(CO) correspondants, des variations faibles mais systématiques de la fréquence d'élongation C=O IR et du déplacement chimique RMN 103Rh fournissent une quantification empirique des effets régio-spécifiques des substituants nitro sur le caractère donneur global du ligand. Les produits secondaires dinucléaires (µ-CO)(LRhCl)2 donnent des cristaux de clathrate uniques à teneur élevée (6,7:1) en solvate de dichlorométhane. La deuxième partie, regroupant cinq chapitres, concerne l'étude de nouveaux types de carbo-mères fortement p-conjugués, principalement conçus pour pallier la faible solubilité limitante du noyau carbo-benzène. La synthèse et la caractérisation des hexaaryl-carbo-benzènes de référence sont revisitées. Une voie de synthèse en 12 étapes améliorée du dérivé hexaphényle connu et de l'homologue p-bis-3,5-di-tert-butylphényle est décrite. Les deux carbo-benzènes ont été entièrement caractérisés, en particulier par analyse par diffraction des rayons X et par électrochimie. Leur utilisation dans les cellules solaires photovoltaïques organiques s'est avérée freinée par leur faible solubilité empêchant la formation de couches minces de haute qualité. Le troisième chapitre porte sur une série de p-dialkyl-tétraphényl-carbo-benzènes à deux chaînes aliphatiques R = CnH2n +1, n = 2, 4, 8, 14, 20. Leur synthèse basée sur l'addition nucléophile de RMgBr sur la [6]péricyclynedione clé conduit à la fois aux dialkyl- et mono-alkyl-carbo-benzènes réduits, le processus de réduction étant supprimé en utilisant un réactif RLi/CeCl3. Une augmentation spectaculaire de la solubilité dans les solvants chlorés a été observée pour n = 8. Un empilement p-p direct des cycles en C18, guidé par les forces de dispersions aliphatiques, a été montré pour la première fois dans la structure cristalline du dérivé bis-tétradécyle, appuyant l'existence de l'allotrope du carbone 3D ?-graphityne (carbo-mère putatif du graphite). Le quatrième chapitre décrit deux trialkoxyaryléthynyl-tétraphényl-carbo-benzènes et l'étude des propriétés mésogènes de l'un d'entre eux. Une mésophase rectangulaire colonnaire, mise en évidence à 115 °C par des analyses DSC, POM et PXRD, ouvre des perspectives pour une étude systématique des cristaux liquides apparentés. Les constantes du réseau 3D sont cohérentes avec les images STM 2D du carbo-mésogène sur HOPG. Le cinquième chapitre décrit trois carbo-mères de squelette de bis- et ter-phényles, conçus pour leur relation aux fils moléculaires OPP ou OPE. Un carbo-terphényle a montré un très faible potentiel de réduction (-0,39 V/SCE), sans précédent en série carbo-mère. Dans le dernier chapitre, de nouveaux types de carbo-mères sont illustrés: les carbo-barrélènes et les carbo-stilbènes. Leur préparation repose sur l'addition de triyne dinucléophiles sur un ou deux équivalents d'un précurseur [6]péricyclyne (di)one. Dans la série tricyclique, deux carbo-barrélènes non macro-aromatiques et un dérivé bis-butatriénique partiellement réduit, se sont révélés suffisamment stables pour permettre une caractérisation complète, y compris par cristallographie. Le rôle de cage d'un carbo-barrélène vis-à-vis de petites molécules telles que NH4+, même si elle n'a pas encore été clairement établie, a été étudiée théoriquement et expérimentalement. Les carbo-stilbènes ont été obtenus sous forme de mélanges. En l'absence d'analyse cristallographique, ils ont été attribués aux diastéréoisomères cis et trans sur la base de la spectroscopie RMN 1H et des calculs DFT. / The manuscript is divided into six chapters and two independent parts, the first part being dedicated to the investigation of the effect of nitro substituents on aromatic phosphine ligands (L). A series of (N-phenyl-benzimidazol-1-yl) diphenylphosphines substituted with 1 to 3 nitro groups at different positions of the N-phenyl and benzimidazolyl cores, were synthesized, and compared with the non-nitrated parent and cationic N-methyl-benzimidazolium counterpart. In the corresponding trans-L2RhICl(CO) complexes, prepared in two steps and fully characterized, moderate but systematic variations of the C=O IR stretching frequency and 103Rh NMR chemical shift provide an empirical quantification of regio-specific effects of the nitro-substituents on the global donating character of the P-ligand. Dinuclear (µ-CO)(LRhCl)2 side-products were shown to give unique clathrate crystals with a high content (6.7:1) of dichloromethane solvate. The second part, gathering five chapters, concerns the study of new types of highly p-conjugated carbo-mers, primarily devised to palliate the limiting poor solubility of the aromatic C18 carbo-benzene core. The synthesis and characterization of reference hexaaryl-carbo-benzenes are revisited. An improved 12-step synthetic route to the long known hexaphenyl derivative and p-bis-3,5-di-tert-butylphenyl homologue is described. Both carbo-benzenes were fully characterized, in particular by X-ray diffraction analysis and electrochemistry. Their use in organic photovoltaic solar-cells was found to be hampered by their very low solubility preventing the formation of high quality thin films. The third chapter focusses on a series of p-dialkyl-tetraphenyl-carbo-benzenes with two aliphatic chains R = CnH2n+1, n = 2, 4, 8, 14, 20. The synthetic route based on nucleophilic addition of RMgBr to a key [6]pericyclynedione ultimately led to both the dialkyl- and reduced mono-alkyl-carbo-benzenes, the reduction process being found suppressed by using a RLi/CeCl3 reactant. A dramatic enhancement of solubility in chlorinated solvents was observed for n = 8. A direct p-p stacking of C18 rings, driven by aliphatic dispersions forces, could be evidenced for the first time in the X-ray crystal structure of the bis-tetradecyl derivative, giving experimental support to the existence of the a-graphityne 3D carbon allotrope (putative carbo-mer of graphite). The fourth chapter describes two trialkoxyarylethynyl-tetraphenyl-carbo-benzenes and the study of the mesogen properties of one of them. A columnar rectangular mesophase, evidenced at 115 oC by DSC, POM and PXRD analyses, opens prospects for a systematic study of related liquid crystals. The 3D lattice constants are consistent with 2D STM images of the carbo-mesogen deposited on HOPG. The fifth chapter reports on three skeletal carbo-mers of bis- and ter-phenyls, devised for their acquaintance with OPP or OPE molecular wires. A carbo-terphenyl was found to exhibit a very low first reduction potential (-0.39 V/SCE), unprecedented in the carbo-mer series. In the last chapter, new types of carbo-mers are exemplified: carbo-barrelenes and carbo-stilbenes. Their preparation relies on the addition of triyne dinucleophiles to either one or two equivalents of a [6]pericyclyne(di)one precursor. In the tricyclic series, two non-macroaromatic carbo-barrelenes and one partially reduced bis-butatrienic derivative, both containing two sp3-C bridgeheads, were found to be sufficiently stable to allow full characterization, including by crystallography. The cage-ability of a carbo-barrelene toward small molecules such as NH4+, albeit not clearly proven yet, was investigated both theoretically and experimentally. The carbo-stilbene product was evidenced as an unseparated mixture of two isomers. In the absence of crystal of suitable quality for crystallography, they were assigned to the cis and trans diastereoisomers on the basis of 1H NMR spectroscopy and DFT calculations.

The goal of cancer chemotherapy is to develop effective, safe, and well-tolerated medications. The over-expression of certain receptors on cancer cell membrane provides a basis for active targeting by not only specific interaction between drug delivery system and cells, but also facilitated cellular uptake via receptor-mediated endocytosis. In this study, LDV oligomers up to six LDV repeating units were synthesized via solid phase peptide synthesis method, and evaluated as drug carrier as well as targeting moiety to deliver doxorubicin (Dox) to human malignant melanoma cells (A375), which over-express integrin α 4 β 1 . Cells expressing different levels of integrin α 4 β 1 or modulated using integrin α 4 -specific siRNA knock-down technique were verified by western blot and PCR. Magnetic beads with tripeptides LDV, VDL, or LNV on the surface were used in the binding specificity studies. Results verified that LDV was the minimally required ligand sequence for the specific binding to integrin α 4 β 1 , of which the interaction depends on the amount of integrin and can be utilized for the design of targeted drug delivery. The studies on A375 cells uptake of FITC-labeled LDV oligomers examined the effects of EDTA, temperature, endocytosis inhibitor, and competitive ligand. Cellular uptake mechanism was revealed to be temperature-dependent, receptor-mediated endocytosis, involving the specific interaction between LDV and integrin α 4 β 1 . The internalization extent of LDV monomer was the highest and was also inhibited to the most by the addition of free LDV when compared to other LDV oligomers. Cytotoxicity profiles of Dox-conjugated LDV oligomers were obtained on wild-type A375, integrin α4 knock-down A375, and normal human epithelial keratinocytes (NHEK) using SRB assay. A significant decrease (3∼6 folds) in the cytotoxicity of oligo(LDV)-Dox on A375 cells were observed when the integrin α4 expression was knocked down by ∼50%. Cytotoxicity further decreased on NHEK, which has the lowest integrin α4 expression among three cell lines. In contrast to oligo(LDV)-Dox, free Dox was not able to differentiate between cancerous and normal cells. This result demonstrated the potential of oligo(LDV) as targeting ligand. However, increase of repeating LDV unit did not lead to any apparent trend in cytotoxicity capacity. To facilitate the intracellular Dox release, hydrazone bond (HYD) was introduced between LDV and Dox. In vitro Dox release profiles in pH 6.0, 7.4, and rat plasma proved the pH-sensitivity of LDV-HYD-Dox. Cytotoxicity studies showed an increased cytotoxic effect of LDV-HYD-Dox when compared with LDV-Dox on wild-type A375 (2.5 times), knock-down A375 (1.5 times); while no significant difference in cytotoxicity on NHEK was observed. In vivo animal study supported the in vitro findings on LDV-HYD-Dox, which showed a significant inhibition of tumor growth and longest mice life span when compared to free Dox, poly(L,D,V)-Dox, and LDV-Dox, with averagely only ¼ of the tumor size and almost twice the life span of that from the free Dox group. In conclusion, based on the concept of specific interaction between LDV and integrin α 4 β 1 , oligo(LDV)-Dox targeted drug delivery system was developed and proved to be effective in the delivery of Dox to melanoma cells.

No description available.

(Metallo-)Dendrimers in Catalysis, Nanoparticle Stabilization and Biological Application Technische Universität Chemnitz, Fakultät für Naturwissenschaften Dissertation 2011, 165 Seiten Die vorliegende Dissertationsschrift befasst sich mit der Darstellung, Charakterisierung und Anwendung neuartiger (Metallo-)Dendrimere. Den Schwerpunkt der Arbeit bildet dabei die terminale Funktionalisierung (Poly)amidoamin-basierender Dendrimere kleiner Generationen. Durch Standardpeptid-Knüpfungsreaktionen von 1,1´-(Diphenylphosphino)ferrocen-carbonsäure an dendritische (Poly)amidoamine ist eine Serie entsprechend funktionalisierter Metallodendrimere zugänglich. Die metallorganischen, Dendrimer-immobilisierten Engruppen können durch Zugabe von [Pd(3-C3H5)Cl]2 in heterobimetallische Übergangsmetallkomplexe umgewandelt werden und finden Einsatz als katalytisch aktive Systeme in C,C-Kreuzkupplungsreaktionen nach Heck. Ein weiterer Gegenstand der Arbeit ist die terminale Modifikation von (dendritischen) Ami-nen mit (Sp)-2-(Diphenylphosphino)ferrocen-1-carbonsäure. Nach erfolgter Umsetzung mit [Pd(3-C3H5)Cl]2 werden die erhaltenen planar-chiralen Verbindungen als Katalysatoren in asymmetrischen allylischen Substitutionsreaktionen eingesetzt. Ferner ist die Darstellung (Oligo)ethylenglykolether-terminierter (Poly)amidoamin-Dendrimere beschrieben. Diese werden als Stabilisatoren zur in-situ Generierung von Gold- sowie Magnetit-Nanopartikeln eingesetzt. Der Einfluss der dendritischen Template auf die Kolloidgrößen und Morphologien sowie die Eigenschaften der gebildeten Hybridmaterialien werden aufgezeigt. Darüber hinaus befasst sich die Arbeit mit der Verwendung biokompatibler (Oligo)ethylenglykolether-Dendrimere als Wirkstoffträger für Zytostatika bei der Krebsthera-pie. Die im Rahmen von in vitro Untersuchungen erhaltenen Ergebnisse werden präsentiert.:Table of Contents Bibliografische Beschreibung und Referat ii Selbstständigkeitserklärung iii Table of Contents vii List of Abbreviations xi Präambel xvi A Introduction 1 1. Dendrimers 1 2. Nanomaterials 4 3. References 7 B State of Knowledge 12 1. Dendrimers 12 1.1. Synthesis and Characterization 12 1.2. Functional Dendrimers 15 2. Characterization Techniques for Dendrimer-Nanomaterial Assemblies 24 3. Motivation 26 4. References 27 C Amidoamine-based Dendrimers with End-grafted Pd-Fe Units: Synthesis, Characterization and Their Use in the Heck Reaction 34 1. Introduction 34 2. Results and Discussion 35 2.1. Synthesis of Amidoamine Dendrimers 35 2.2. Synthesis of Metallo- and Selenium-Phosphine Amidoamine Dendrimers 36 2.3. Catalysis with Heterobimetallic Iron-Palladium Amidoamine Dendrimers 39 3. Conclusions 41 4. Experimental 42 4.1. Materials and Methods 42 4.2. Preparation of 2 43 4.3. Preparation of 9-Fe 43 4.4. Preparation of 5-Fe-Pd 44 4.5. Preparation of 6-Fe-Pd 44 4.6. Preparation of 7-Fe-Pd 45 4.7. Preparation of 8-Fe-Pd 46 4.8. Preparation of 9-Fe-Pd 46 4.9. Preparation of 5-Fe-Se 47 4.10. Preparation of 9-Fe-Se 48 4.11. General Procedure for the Heck-Reaction 48 5. Acknowledgement 49 6. References 49 D A Preparation of Planar-Chiral Multidonor Phosphanyl-Ferrocene Carboxamides and Their Application as Ligands for Palladium-Catalyzed Asymmetric Allylic Alkylation 52 1. Introduction 52 2. Results and Discussion 53 2.1. Syntheses and Characterization 53 2.2. Solid-State Structure of (Sp)–2 55 2.3. Catalytic Tests 57 3. Conclusions 58 4. Experimental 59 4.1. Materials and Methods 59 4.2. Preparation of Simple Amides. A General Procedure 59 4.3. Preparation of 6 61 4.4. Preparation of (Sp,Sp)–4 61 4.5. Preparation of 7 62 4.6. Preparation of (Sp,Sp,Sp)–5 62 4.7. Asymmetric Allylic Alkylation. A General Procedure 63 4.8. X-ray Crystallography 63 5. Acknowledgements 64 6. References 64 E Au Nanoparticles Stabilized by PEGylated Low-Generation PAMAM Dendrimers: Design, Characterization and Properties 68 1. Introduction 68 2. Materials and Methods 69 2.1. Synthesis of Stabilizers 69 2.2. Preparation Procedure for Gold Nanoparticles 70 3. Results and Discussion 70 3.1. Dendritic Stabilizers 70 3.2. Dendritic Stabilized Gold Nanoparticles 72 3.3. Physical and Chemical Characterization 73 4. Conclusion 79 5. Acknowledgement 80 6. Supplementary Material 80 7. References 80 F Design, Characterization and Magnetic Properties of Fe3O4-Nanoparticle Arrays Coated with PEGylated-Dendrimers 86 1. Introduction 86 2. Materials and Methods 88 2.1. Materials and Instruments 88 2.2. Synthesis Procedure for Fe3O4 Nanoparticles 89 3. Results and Discussion 91 3.1. Preparation and Characterization of Dendrimer-Surfaced Fe3O4 Nanoparticles 91 3.2. Magnetic Characterization of Dendrimer-Coated Fe3O4 Nanoparticles 96 4. Conclusion 99 5. Acknowledgement 100 6. References 100 G Dendrimer - Doxorubicin Conjugate for Enhanced Therapeutic Effects for Cancer 103 1. Introduction 103 2. Experimental Section 105 2.1. Materials and Methods 105 2.2. Synthesis of OEGylated Poly(amidoamine) Dendrimer 2 106 2.3. Cell Viability Studies 107 2.4. Doxorubicin Loading and Release 107 2.5. In Vitro Cellular Uptake of Dendrimer-DOX Conjugate 109 3. Results and Discussion 109 3.1. Drug Loading and Release 109 3.2. Surface Potential of the Dendrimer-Drug Assembly 110 3.3. Structural Analysis of Dendrimer-DOX Conjugate 111 3.4. In Vitro DOX Release Profile from Dendrimer-Drug Conjugate 114 3.5. Cell Viability Studies of the Dendrimer-DOX Conjugate 117 3.6. Cellular Uptake by the Dendrimer-DOX Conjugate 118 3.7. Protein Adsorption Studies 119 4. Conclusions 119 5. Acknowledgements 120 6. Supplementary Material 120 7. References 121 H Summary 123 1. Summary 123 2. Zusammenfassung 129 Danksagung 136 I Appendix 137 1. Appendix Chapter C 137 2. Appendix Chapter D 139 3. Appendix Chapter E 140 4. Appendix Chapter F 142 5. Appendix Chapter G 144 Lebenslauf 145 Liste der Publikationen, Vorträge und Posterpräsentationen 147 Publikationen 147 Poster 148 Vorträge 149

<p> Over the past decade, the development of surface-initiated living polymerization methods has brought a breakthrough to surface modification owing to their control ability. Surface-initiated atom transfer radical polymerization (si-ATRP), as the most popular one, has been widely employed to give novel polymer structures and functionalities to various surfaces for the purposes of tailoring surface properties, introducing new functions, or preparing so-called "smart surfaces", which can respond to external stimuli such as solvent type, pH, temperature, electric and magnetic fields etc. In this thesis, the mechanistic study of the si-ATRP was first carried out through modeling to gain good understanding of si-ATRP. Si-ATRP was then employed to prepare different types of polymer brushes to produce "smart surfaces". </p> <p> The kinetic model was developed using the method of moment. Combined with experimental data, a quantitative analysis was carried out for the si-ATRP mechanism. All information of grafted polymer chains, including active chain concentration, radical concentration, chain length, polydispersity, was illustrated. A new radical termination mechanism, termed as migration-termination, was proposed for si-ATRP. </p> <p> Si-ATRP was then employed to graft poly(oligo(ethylene glycol) methacrylate) (POEGMA) block poly(methyl methacrylate) (PMMA) brushes on silicon wafer surfaces. Simple solvent treatment gave nanoscale patterns via the phase segregation of POEGMA and PMMA segments. Various patterns including spherical aggregates, wormlike aggregates, stripe patterns, perforated layers and complete overlayers, were obtained by adjusting the upper block layer thickness. Furthermore, these nanopatterns had a unique stimuli-responsive property, i.e., switching between different morphologies reversibly after being treated with selective solvents. </p> <p> POEGMA-block-poly(2-(methacryloyloxy)ethyl trimethylammonium chloride) (PMETAC) brushes, having two hydrophilic segments, were synthesized by si-ATRP method. A variety of nanopatterns and their stimuli-responsive ability were observed. The adsorption behaviors of fibrinogen on these patterns were thoroughly studied by ellipsometry, water contact angel measurement, AFM and radio labelling method. </p> <p> A novel thermo-responsive copolymer, poly(2-(2-methoxyethoxy)ethyl methacrylate -co-oligo(ethylene glycol) methacrylate) (P(ME02MA-co-OEGMA)), was also grafted onto silicon wafers. Its thermo-responsive behavior and chain conformation in aqueous solution were studied by neutron reflectometry (NR). Both extended and collapsed brushes exhibited good protein adsorption resistance. </p> / Thesis / Doctor of Philosophy (PhD)