Die vorliegende Arbeit beinhaltet die Synthese neuartiger Hybridmaterialien basierend auf der Einlagerung optischer Materialien, wie Farbstoffmoleküle und Metallnanopartikel, in anorganische Wirtsmaterialien mit definierten Porenstrukturen. Hierfür wurden mikro- und mesoporöse alumosilikatische Verbindungen, wie z.B. Zeolithe und Vertreter aus der Familie der sogenannten „Mobile Composition of Matter“ (MCM), verwendet. Mit Hilfe dieses Konzeptes konnte z.B. der Einfluss der Wirtsmaterialien hinsichtlich ihrer Porengrößen und inneren Polarität auf die optischen Eigenschaften von photochromen Naphthopyranfarbstoffen untersucht werden. Neue photochrome Kompositmaterialien, welche sich durch einfache industrielle Prozesse, wie z.B. der Extrusion in eine Polymermatrix, weiterverarbeiten lassen, wurden auf diesem Wege synthetisiert. Durch die Einkapselung eines solvatochromen Spiropyranderivats innerhalb der Superkäfige von Faujasiten konnten Rückschlüsse auf die Polaritätsparameter der äußeren und inneren Oberfläche der Molekularsiebe gewonnen werden. Zudem wurde ein neues Synthesekonzept zur Herstellung fluoreszierender Silbernanopartikel innerhalb eines Zeolith Y entwickelt, um auf sehr einfachem Weg ein stabiles Material mit interessanten Fluoreszenzeigenschaften zu erhalten. Der Einfluss der Wirtsoberfläche auf fluoreszierende Farbstoffe wurde des Weiteren an Benzylidenketonfarbstoffen untersucht, die mittels „Ship in a Bottle reaction“ in Zeolith Y eingekapselt wurden. Um das Konzept zur Synthese optischer Effektpigmente zu erweitern, wurden neue photochrome Naphthopyrane, welche in Konjugation zu fluoreszierenden Farbstoffen stehen, synthetisiert und untersucht.

The demand for multifunctional nanocontainers possessing both recognition ability and responsive nature is increasing greatly because of their high potential in various biomedical applications. The engineering of such smart nanovesicles is useful to enhance the efficiency of many therapeutic and diagnostic tools that have the applicability in targeted drug delivery systems as well as designing sensing devices or conducting selective reactions as nanoreactors in the scope of nanobiotechnology. For this purpose, this study demonstrates the formation of multifunctional and stimuli-responsive polymersomes comprising various abilities including pH and light sensitivity as well as many reactive groups with sufficient accessibility to be used as smart and recognitive nanocontainers. The fabrication included several steps starting from the synthesis of azide and adamantane terminated block copolymers, which were then self-assembled to prepare the polymersomes with the corresponding functional groups for the subsequent post-conjugations at the vesicle periphery. The accessible and sufficiently reactive groups were quantitatively proven when UV and IR cleavable NVOC protected amino groups as well as β-cyclodextrin molecules were conjugated to the pre-formed polymersomes through click chemistry and strong host-guest complexations. The gained light responsivity with the aid of successful NVOC attachment enabled further selective photochemical reactions triggered either by UV or NIR light leading to liberated amine groups on the polymersome surface. Therein, these released amino groups were further conjugated with a model fluorescent compound as mimicking the attachment of biorecognition elements to see the direct picture of the applicability. To realize this concept in a more localized and selective way as well as to avoid the possible side effects of UV light, the NIR-light induced photochemical reactions and further dye coupling were performed when polymersomes were immobilized onto solid substrates. This fixation was achieved by adapting the host-guest chemistry into this part and conjugating the adamantane decorated polymersomes onto β-cyclodextrin coated substrates. Several investigations including adhesion behavior, pH sensitivity and mechanical properties of the established multifunctional polymersomes under liquid phase have been performed. It has been found that the polymersome shape is highly dependent on the attractive forces of the substrate and needs to be optimized to avoid the flattening of the vesicles. For these optimization steps, different conditions were investigated including the decrease of cyclodextrin amount and additional surface passivation with PEG molecules on the solid substrates. Besides, the calculated Young’s and bending modulus of the polymersome membrane from AFM measurements showed a robust but still flexible “breathable” membrane which is an important criterion for the applicability of these smart and stable vesicles. In addition, the hosting ability as well as diffusion limits and sufficient membrane permeability of the polymersomes were observed by encapsulating gold nanoparticles as a smart cargo and doxorubicin molecules as an anticancer drug. In conclusion, the established multifunctional polymersomes are highly versatile and thus present new opportunities in the design of targeted and selective recognition systems which is highly interesting for various applications including development of microsystem devices, design of chemo/biosensors, and also for conducting enhanced, combined therapy in the field of drug delivery.

The demand for multifunctional nanocontainers possessing both recognition ability and responsive nature is increasing greatly because of their high potential in various biomedical applications. The engineering of such smart nanovesicles is useful to enhance the efficiency of many therapeutic and diagnostic tools that have the applicability in targeted drug delivery systems as well as designing sensing devices or conducting selective reactions as nanoreactors in the scope of nanobiotechnology. For this purpose, this study demonstrates the formation of multifunctional and stimuli-responsive polymersomes comprising various abilities including pH and light sensitivity as well as many reactive groups with sufficient accessibility to be used as smart and recognitive nanocontainers. The fabrication included several steps starting from the synthesis of azide and adamantane terminated block copolymers, which were then self-assembled to prepare the polymersomes with the corresponding functional groups for the subsequent post-conjugations at the vesicle periphery. The accessible and sufficiently reactive groups were quantitatively proven when UV and IR cleavable NVOC protected amino groups as well as β-cyclodextrin molecules were conjugated to the pre-formed polymersomes through click chemistry and strong host-guest complexations. The gained light responsivity with the aid of successful NVOC attachment enabled further selective photochemical reactions triggered either by UV or NIR light leading to liberated amine groups on the polymersome surface. Therein, these released amino groups were further conjugated with a model fluorescent compound as mimicking the attachment of biorecognition elements to see the direct picture of the applicability. To realize this concept in a more localized and selective way as well as to avoid the possible side effects of UV light, the NIR-light induced photochemical reactions and further dye coupling were performed when polymersomes were immobilized onto solid substrates. This fixation was achieved by adapting the host-guest chemistry into this part and conjugating the adamantane decorated polymersomes onto β-cyclodextrin coated substrates. Several investigations including adhesion behavior, pH sensitivity and mechanical properties of the established multifunctional polymersomes under liquid phase have been performed. It has been found that the polymersome shape is highly dependent on the attractive forces of the substrate and needs to be optimized to avoid the flattening of the vesicles. For these optimization steps, different conditions were investigated including the decrease of cyclodextrin amount and additional surface passivation with PEG molecules on the solid substrates. Besides, the calculated Young’s and bending modulus of the polymersome membrane from AFM measurements showed a robust but still flexible “breathable” membrane which is an important criterion for the applicability of these smart and stable vesicles. In addition, the hosting ability as well as diffusion limits and sufficient membrane permeability of the polymersomes were observed by encapsulating gold nanoparticles as a smart cargo and doxorubicin molecules as an anticancer drug. In conclusion, the established multifunctional polymersomes are highly versatile and thus present new opportunities in the design of targeted and selective recognition systems which is highly interesting for various applications including development of microsystem devices, design of chemo/biosensors, and also for conducting enhanced, combined therapy in the field of drug delivery.

Die vorliegende Arbeit beinhaltet die Synthese neuartiger Hybridmaterialien basierend auf der Einlagerung optischer Materialien, wie Farbstoffmoleküle und Metallnanopartikel, in anorganische Wirtsmaterialien mit definierten Porenstrukturen. Hierfür wurden mikro- und mesoporöse alumosilikatische Verbindungen, wie z.B. Zeolithe und Vertreter aus der Familie der sogenannten „Mobile Composition of Matter“ (MCM), verwendet. Mit Hilfe dieses Konzeptes konnte z.B. der Einfluss der Wirtsmaterialien hinsichtlich ihrer Porengrößen und inneren Polarität auf die optischen Eigenschaften von photochromen Naphthopyranfarbstoffen untersucht werden. Neue photochrome Kompositmaterialien, welche sich durch einfache industrielle Prozesse, wie z.B. der Extrusion in eine Polymermatrix, weiterverarbeiten lassen, wurden auf diesem Wege synthetisiert. Durch die Einkapselung eines solvatochromen Spiropyranderivats innerhalb der Superkäfige von Faujasiten konnten Rückschlüsse auf die Polaritätsparameter der äußeren und inneren Oberfläche der Molekularsiebe gewonnen werden. Zudem wurde ein neues Synthesekonzept zur Herstellung fluoreszierender Silbernanopartikel innerhalb eines Zeolith Y entwickelt, um auf sehr einfachem Weg ein stabiles Material mit interessanten Fluoreszenzeigenschaften zu erhalten. Der Einfluss der Wirtsoberfläche auf fluoreszierende Farbstoffe wurde des Weiteren an Benzylidenketonfarbstoffen untersucht, die mittels „Ship in a Bottle reaction“ in Zeolith Y eingekapselt wurden. Um das Konzept zur Synthese optischer Effektpigmente zu erweitern, wurden neue photochrome Naphthopyrane, welche in Konjugation zu fluoreszierenden Farbstoffen stehen, synthetisiert und untersucht.