Engineering artificial cells is currently an emerging area of research that involves constructing mimics of biological cells. These biomimetic cellular systems hold tremendous promise for the different biomedical applications (diagnostics, therapy, tissue engineering, gene transfection, bioactive coatings) as well as aspects of synthetic biology. A key architectural principle of the cell is a multicompartmentalized assembly, which is one of the features of biological cells that enable the performance of multiple complex biochemical reactions within confined environments. For this purpose, this study demonstrates novel artificial cells, not only presenting organelle mimics but also incorporating various stimuli for regulating enzymatic cascade reactions within the artificial cell and for controlled simultaneous and/or subsequent release of the encapsulated (therapeutic) molecules. To successfully fabricate the multifunctional polymeric multicompartmentalized systems as artificial cells aimed for, in the first step a hollow capsule as biomimetic cellular membrane was developed to simulate a key characteristic of functional artificial cells for the selective uptake and release of (bio)molecules and particles for intra- and intercellular signaling processes. Herein using LbL technique which involved alternate deposition of oppositely charged polyelectrolytes on silica template via electrostatic interaction, the pH and temperature dual-responsive and photo-crosslinked hollow capsule was fabricated and they can be used for the subsequent post-encapsulation process of protein-like macromolecules (≤ 11 nm) and their controllable release triggered by external stimuli for mimicking the controllable bio-inspired functions of cell membranes. The reversible temperature and pH dual-response ability of the hollow capsules has been analyzed. The uptake and release properties of the resulting hollow capsules with different degree of photo-crosslinking for cargos have been further investigated at various temperatures (25, 37 or 45°C) and pH (5.5 or 7.4) of the solution. Next, the design of the polymersomal subcompartmens as organelle mimics, which divide the interior of the multicompartmentalized systems into subcompartments and can stably encapsulate fragile hydrophobic and hydrophilic cargo, e.g., enzymes in order to conduct encapsulated catalysis-resembling cell organelles, was also an important subject. The fabrication of these subcompartments was starting with the synthesis of suitably end-group block copolymers to realize the enzyme-loaded, multifunctional, pH-responsive, photo-crosslinked and post-labelled polymersomes decorated with adamantane groups. The pH sensitivity and various enzymatic reactions of the established multifunctional Ada-polymersomes have been investigated. Based on the above concepts, a bottom-up approach was developed to assemble a structural and functional eukaryotic cell mimics, including “membrane-associated” multicompartmentalized system (MS1) and “free-floating” multicompartmentalized system (MS2), by loading pH-sensitive Ada-polymersomes inside the multifunctional cell membrane. The creation of these multicompartmentalized systems was based on the assembly of enzyme-loaded Ada-polymersomes as organelle mimics onto sacrificial particle templates by host-guest interaction, followed by the LbL deposition of temperature-responsive and photo-crosslinkable PMA(β-CD)/[PAH/PNMD]3 multilayers and outer protective capping PAH/PMA(PEG) bilayer as biomimetic cellular membrane. Upon photo-crosslinking the polymer biomimetic membrane and dissolution of the particle templates, multicompartmentalized systems were obtained. Spatial position of the subcompartments can be controlled using non-covalent host-guest concept, which yielded multicompartmentalized systems containing “membrane-associated” and “free-floating” subunits. Moreover, the metabolism mimicry of multicompartmentalized systems by performing multiple successive two-enzyme cascade reactions in the cells and the multiple parallel reactions by using a third enzyme for deactivating the reaction product and interfering the cascade reaction have been investigated. In conclusion, these multicompartmentalized systems, combining the advantages of both pH-responsive Ada-polymersomes as organelle mimics and multifunctional hollow capsule as biomimetic cellular membrane, present new opportunities for the development of functional cell mimics. The presented studies highlight crucial aspects for the successful applications of such cell mimics for diagnostics, tissue engineering, as nanoreactors, as carriers for multiple drug delivery with controlled release profiles, or as therapeutic artificial cells.

MIMICS is an acronym for Multitouch Interface as a MIDI Control Suite. Multitouch interfaces are well known for their softer learning curve compared with classical computer graphic interfaces. Therefore, its application in music interfaces may solve some of the actual limitations of hardwarebased and software-based devices. The multitouch solution is based on an optical effect called Frustrated Total Internal Reflection which is forced by using infrared light sources. This effect allows finger tracking using computer vision engines. In the thesis we describe a low-cost and affordable Hardware/Software solution for MIDI-based devices control from a functional multitouch environment. The MIMICS is presented to the user as a rear projected 30 inches screen containing a graphical interface adapted for multitouch. Implementation of several ‘ready-to-play’ applications is demonstrated that emulate classical and new MIDI control devices. The report also contains an evaluation of the results demonstrating that MIMICS is suitable for life-oriented music performances as well as for recording studio works.

Steroids are one of the essential classes of bioactive compounds and are involved in many biological functions which include their role as signaling compounds, the alteration of membrane fluidity and the regulation of a variety of metabolic processes. In order to identify novel compounds with beneficial pharmacological action, the synthesis of modified steroids is gaining much attention in recent years. Among those analogs, azasteroids are one of the most important classes which display a variety of biological activities, often free from undesirable side effects. The challenges in the synthesis of steroids, particularly azasteroids, and the potential of azasteroids as novel drugs has prompted numerous investigations in this field. The synthetic methods leading to steroidal derivatives (azasteroids) with one or more nitrogen atoms are very limited. Generally, oxidative cleavage of the steroidal rings is needed to introduce nitrogen atom(s) in order to synthesize azasteroids. In the first part of this dissertation, explorations into the synthetic methods needed for making a new steroidal A-ring or seco A-ring on a tricyclic benz[e]indenedione (a dimer compound obtained in connection with continued work on the study of anhydrobases of the isoxazole series) were pursued. In this process, a series of three tricyclic hydrazone compounds have been designed and synthesized to mimic the tetracyclic rigid core structure of azasteroids. We are eager to ascertain if these compounds possesses any interesting biological properties. In continued research on the synthesis of azulenyl and pseudoazulenyl nitrones, (to target ROS generation at the site of mitochondria), the second part of this research was aimed at the synthesis of cationic pseudoazulenyl nitrones with mitochondriotropic properties. Several pseudoazulenyl nitrone derivatives were synthesized using the natural compound valtrate, obtained from the roots of Centranthus ruber. Unfortunately, the attempts made to convert these compounds into the corresponding cationic pseudoazulenyl nitrones failed. However, an interesting pseudoazulenyl dinitrone molecule bearing an imidazole group was prepared. Also, a pseudoazulenyl mono nitrone compound with an electron donating group was synthesized by leaving a highly reactive aldehyde functionality intact for further use in synthetic study.

Tiefe sternale Wundheilungsstörungen sind seltene, aber verheerende Komplikationen nach medianer Sternotomie. Die verminderte Durchblutung von Knochen- und Weichgewebe nach Verwendung der Arteria thoracica interna (ITA) in der kardiochirurgischen Bypass-Chirurgie, begünstigt die Entwicklung von Wundheilungsstörungen. Das Ziel dieser Studie war die makroskopische und radiologische Darstellung des sternalen Gefäßsystems im Hinblick auf mögliche Kollateralkreisläufe. Das methodische Vorgehen gliederte sich in die makroskopischen Präparation, die Segmentierung mittels Mimics® und deren semi-quantitativer Vergleich. Bei der makroskopischen Präparation wurden vier Thorax-Schilde (vordere Brustwand), zwei Alkohol- und zwei Thiel-fixierte Schilde, entnommen und die ITA und deren Abgänge präpariert. Da nach Thiel-Fixierung Gewebe realitätsnahe Eigenschaften behalten, blieben die weichen Gefäße durchgängig und eigneten sich besonders zur Injektion des Microfil®-Gemisches oder der Arterienmasse nach Thiel (1992). Ein weiterer Vorteil der Massen war die Röntgenopazität, wodurch radiologische Untersuchungen am Präparat erfolgten. Da die segmentierungsbasierte Rekonstruktion zunehmend Einzug in die Diagnostik hält, wurden zur Diskussion, ob Kollateralkreisläufe des Sternums dargestellt werden können, zwei Thorax-CTs erstellt und mittels Mimics® segmentiert. Die im Rahmen dieser Studie angewandten Methoden konnten das makroanatomische Gefäßsystem des Sternums darstellen, wobei die Injektion der Arterienmasse am Thiel fixierten Humanpräparat mit anschließender Segmentierung besonders geeignet war.:Inhaltsverzeichnis Abkürzungen viii 1 Einleitung 1 1.1 Problemstellung 1 1.2 Anatomie des Thorax 2 1.2.1 Anatomie des knöchernen Thorax 3 1.2.2 Anatomie des Sternums 3 1.2.2.1 Blutversorgung des Sternums 5 1.3 Die A. thoracica interna (ITA) 6 1.4 Die mediane Sternotomie 8 1.5 Tiefe sternale Wundheilungsstörungen (DSWI) 9 1.5.1 Definition DSWI 9 1.5.2 Risikofaktoren DSWI 11 1.5.3 Therapie 12 1.6 Methoden zur Darstellung der Gefäßversorgung des Sternums 14 1.6.1 Allgemeines 14 1.6.2 Fixierung und Konservierung 14 1.6.3 Präparations- und Injektionstechnik 15 1.6.4 Segmentierungsbasierte Rekonstruktion mit Mimics® 15 2 Material und Methodik 17 2.1 Untersuchungsmaterial 17 2.2 Fixierungen 19 2.2.1 Alkohol-Fixierung 19 2.2.2 Thiel-Fixierung 21 2.3 Übersicht der Methodik 27 2.4 Makroskopische Präparation 28 2.4.1 Präparation des Thorax-Schildes 28 2.4.2 Präparation der ITA und ihrer Abgänge 31 2.5 Injektionstechniken am Thiel-fixierten Präparat 33 2.5.1 Anwendung des Microfil®-Gemisches 33 2.5.2 Arterienmasse nach Thiel für die makroskopische Präparation 37 2.6 Segmentierungsbasierte Rekonstruktion mittels Mimics® 45 2.6.1 Kontrastmittel-CT 49 2.6.2 Arterienmasse nach Thiel für die Computertomographie 54 2.7 Semi-quantitative Beurteilung der Methoden 56 2.8 Systematische Literaturrecherche 58 2.9 Statistische Auswertung 61 2.10 Fotografische und bildliche Dokumentation der Präparate 61 3 Ergebnisse 62 3.1 Makroskopische Präparation der ITA und ihrer Abgänge 62 3.1.1 Länge der ITA 62 3.1.2 Abgänge der ITA 63 3.2 Semi-quantitative Beurteilung der makroskopischen Präparation 67 3.2.1 Alkohol-fixierte Präparate 67 3.2.2 Thiel-fixierte Präparate 69 3.2.2.1 Thorax-Schild ohne Injektionstechnik 69 3.2.2.2 Thorax-Schild mit Injektionstechnik - Microfil®-Masse 71 3.2.2.3 Thorax-Schild mit Injektionstechnik – Arterienmasse nach Thiel 75 3.3 Semi-quantitative Beurteilung der segmentierungsbasierten Rekonstruktion mit Mimics® 78 3.3.1 Kontrastmittel-CT 79 3.3.2 Arterienmasse nach Thiel 86 4 Diskussion 98 4.1 Länge der ITA 99 4.2 Methodenvergleich zur Darstellung der ITA 99 4.2.1 Alkohol- vs. Thiel-Fixierung (ohne Injektion) 101 4.2.2 Alkohol- vs. Thiel-Fixierung (Microfil®) 102 4.2.3 Arterienmasse nach Thiel vs. Microfil® 103 4.3 Segmentierungsbasierte Rekonstruktion 105 4.3.1 Interpretation der Bilder und Methodenvergleich 106 4.4 Vergleich mit anderen Methoden zur Gefäßdarstellung 109 4.5 Schlussfolgerung 112 5 Zusammenfassung 113 6 Literaturverzeichnis 115 7 Abbildungsverzeichnis 120 8 Tabellenverzeichnis 123 9 Danksagung 124 10 Ehrenwörtliche Erklärung 125 11 Lebenslauf 126 12 Anhang 127

NKT cells are an important part of human immune system and recognize a specific set of antigens called glycolipids. Only a handful of "natural" NKT cell antigens are known till date. Although NKT cells play a protective role against pathogenic organisms, imbalances in NKT cell functions are implicated in many diseases including asthma. Allergic asthma, a Th2 driven inflammation of airways, is primarily caused by inhalation of environmental allergens. In the last decade, inhaled allergen Aspergillus fumigatus has been under scrutiny for the presence of NKT cell antigens that might trigger asthma. We successfully isolated, characterized and synthesized a "natural" antigenic glycolipid which activates NKT cells in CD1d dependent manner. When this glycolipid is administered intranasally to mice, WT but not CD1d-/- mice developed airway hyperreactivity (AHR), which is a cardinal feature of asthma. Our results indicate that this glycolipid also triggers the production of key cytokines responsible for development of airway hyperreactivity, namely IL-4 and IL-13. Widespread use of antibiotics has convoluted the problem of antimicrobial resistance. Our research group has developed a novel class of antimicrobial peptide mimics called Ceragennins. These cholic acid based antimicrobial compounds have many desirable properties including low MICs, effectiveness against biofilms, and relatively low manufacturing cost. In order to advance the clinical development of Ceragennins, we developed analytical methods for qualitative and quantitative determination of these compounds in complex biological matrices. These methods were also used for carrying out the stability studies of Ceragenins under varying pH and temperatures

Self-assembly is a fundamental process in the field of nanotechnology, where molecules organize into complex structures spontaneously or induced by environmental factors. Peptides, short chains of amino acids, can self-assemble into many types of nanostructures. The self-assembly of peptides is governed by noncovalent interactions, including electrostatic interactions, hydrogen bonding, hydrophobic interactions, aromatic-aromatic interactions, and van der Waals forces. By varying the amino acid sequences and manipulating environmental parameters, these interactions can be modulated to obtain diverse supramolecular nanostructures, exhibiting a wide range of physical, chemical, and biological properties. Furthermore, the ability to control these properties opens up a world of possibilities in biomedical and biocatalytic applications. From drug delivery systems to enzyme mimics, as well as cancer treatments, the potential of these self-assembling peptides is vast and continues to be a vibrant area of research. Exploiting this potential, this dissertation delves into the design, synthesis, and investigation of self-assembling peptides for a range of applications. The introductory chapters of this document lay the groundwork, providing a comprehensive overview of self-assembly and its potential in biocatalytic and biomedical domains. The focus shifts in the later chapters to drug delivery applications, particularly in the delivery of hydrogen sulfide (H2S), and its implications in cardioprotection and cancer treatment. Finally, this document details an evaluation of self-assembled peptides in the context of biocatalysis using a combined experimental and computational approach. Chapter 3 discusses the design and synthesis of peptide-H2S donor conjugates (PHDCs) with an unusual adamantyl group. Several of PHDCs studied in this chapter self-assembled into novel nanocrescent structures observed under both conventional transmission microscopy (TEM) and cryogenic TEM (cryo-TEM). By varying the C-terminal amino acid with cationic, nonionic, or anionic amino acids, the PHDC morphologies remained unaffected, offering a robust peptide design for crescent-shaped supramolecular nanostructures. Chapter 4 discusses an extension of this project, introducing a cyclohexane in PHDCs instead of an adamantyl group. In this work, we designed and fabricated four constitutional isomeric PHDCs, which self-assembled into nanoribbons with different dimensions and large nanobelts. These morphologies exhibited varying cellular uptake and in vitro H2S release amounts, influencing their protective effects against oxidative stress induced by H2O2. With the knowledge of the impact of subtle changes in PHDC structures, Chapter 5 discusses our further design of three more PHDCs with the variation of side chain capping group, from an aromatic phenyl ring to a cyclohexane unit, to an aliphatic n-hexyl chain. In this chapter, we studied how changes in the hydrocarbon tail can influence the supramolecular nanostructures and their potential ability for colon cancer treatment. A final aspect of H2S delivery in Chapter 6 involves the creation of a stable PHDC with an extended H2S release profile. By integrating the H2S donor into a β-sheet forming peptide sequence with a Newkome-like poly(ethylene glycol) dendron, this PHDC self-assembles into spherical or fibril nanostructures with or without stirring. The H2S release was further studied by triggering release with various charged thiol molecules. Finally, another facet of this document focuses on three constitutional isomeric tetrapeptides containing a catalytic functional amino acid, His. Chapter 7 discusses these tetrapeptides, which self-assembled into nanocoils, nanotoroids, and nanoribbons based on the position of the His residue in the peptide sequence. Computational studies simulating the self-assembling process revealed the distribution of His residues and hydrophobic pockets, reminiscent of natural enzyme binding sites. A tight spatial distribution of His residues and hydrophobic pocket in nanocoils provided a picture for why this morphology exhibited the highest rate enhancement in catalyzing a model ester hydrolysis reaction. This study demonstrated how subtle molecular-level changes impact supramolecular nanostructures and catalytic efficiency. The final chapter details conclusions on all the research in this dissertation and discusses further directions of self-assembling peptides in the application of drug delivery and design of catalyst mimics. / Doctor of Philosophy / Self-assembly is a fascinating process in nanotechnology, where molecular building blocks come together to form complex structures. Peptides, which are short chains made up of amino acids, can play a crucial role in this process. They can organize themselves into various shapes due to different forces acting between their amino acid building blocks. By changing the arrangement of amino acids and adjusting the environment, scientists can create a wide range of nanoscale structures with unique properties from peptides. These self-assembling peptides have enormous potential in fields like medicine and catalysis. This dissertation describes how to design and make self-assembling peptides for various uses. Chapter 1 describes the general structure of the document, and Chapter 2 discusses the basics of self-assembly and how it can be applied in medicine and other areas. Chapters 3-6 focus on using self-assembling peptides to deliver hydrogen sulfide (H2S), a noxious gaseous molecule that is now recognized as a vital signaling molecule involved in various physiological processes. Several classes of peptide-H2S donor conjugates (PHDCs) are discussed in these chapters, including PHDCs that form nanoscale crescents, twisted ribbons, fibers, and other structures. These nanostructures show promise in protecting cells from harmful substances or can act as drugs in cancer treatment. We also investigate how different modifications affect their performance in biomedical applications. The final research chapter, Chapter 7, involves using self-assembling peptides as catalysts, molecules that speed up chemical reactions. By arranging the amino acids in different ways, peptides that form nanoscale coils, toroids, or ribbons-like structures were created. These different shapes influenced how well they catalyzed reactions. Computational modeling studies helped explain how small differences in molecular design led to big impacts on their catalytic abilities. The final chapter discloses conclusions on all the research in this dissertation and discusses the further directions of self-assembling peptides as medicines and catalysts.

Blood vessel mimics (BVMs) are tissue engineered blood vessels that are intended as an intermediate testing environment for intravascular devices, such as stents. Specifically, Cal Poly’s Tissue Engineering Lab hypothesizes that BVMs can be used to test endothelial cell and smooth muscle cell responses to existing and new vascular stents. Characterization techniques are required for BVMs to be accepted as a valid testing model, prior to being employed as an in vitro model to determine the effects of medical treatments. Quantitative real-time polymerase chain reaction (qPCR) is one available option for evaluating gene expression of tissues. qPCR can be performed on DNA synthesized from RNA isolated from cells, and in this application, will provide quantitative information on what proteins where being transcribed within the cells at the time of RNA isolation. qPCR can be used to determine the proteins expressed in BVMs at baseline in order to then characterize changes in protein expression induced by stent deployment within the BVM. The aim of this thesis was to optimize existing qPCR protocols, and implement the optimized protocols to characterize gene expression of stented and unstented blood vessel mimics (BVMs) and cells from a donor with Diabetes grown in Cal Poly’s Tissue Engineering Laboratory. To accomplish this goal, existing qPCR protocols were evaluated and modified to ensure reproducible, valid results were produced. Standard operating procedures were created for RNA isolation, cDNA synthesis, qPCR and qPCR data analysis. Optimized qPCR methods were then applied to BVMs from umbilical and coronary cell sources to compare the models and to study the BVM responses to stent deployment. Additional primers were also identified for potential usage as reference genes and as diabetic markers for diseased BVMs.

No description available.

Platinum-Group Metal (PGM) nanostructures as advantageous alternatives to natural peroxidases have drawn great attention because of their superior catalytic activities, which can effectively enhance performance of enzyme-based in vitro diagnostics. The catalytic activity of metal nanoparticle peroxidase mimics can depend on their size, shape, elemental composition, and surface ligand of PGM nanostructures. Therefore, to develop optimal peroxidase mimics for a few bioanalytical and diagnostic applications, such as enzyme-linked immunosorbent assay (ELISA), it is important to investigate how structural aspects of PGM nanoparticles correlate with the ability of the nanoparticles to serve as functional mimics of protein peroxidase enzymes. In summary, this dissertation has studied: 1) iridium (Ir), platinum (Pt) and Ir/Pt bimetallic nanowire structures as peroxidase mimics, and the effect of different wires' length on their peroxidase-like activities and certain application of sandwich ELISA for the detection of carcinoembryonic antigen (CEA, a cancer biomarker); 2) ultra-small Ir nanoparticles, with an average size of 1.1 nm, supported by WO2.72 nanowire with high catalytic activity. Those Ir nanoparticles were applied to sandwich ELISA and competitive ELISA for sensitive detection of CEA and aflatoxin B1 (AFB1, a carcinogenic toxin), respectively; 3) the size effect of peroxidase mimics on their catalytic activities and performance in biosensing application, where Pd-Ir core-shell nanoparticles were used as a type of model peroxidase mimics. These studies may significantly stimulate further investigations of PGM nanostructures as peroxidase mimics and other potential applications in in vitro diagnostics.

No description available.