To improve measurement reliability and repeatability and resolve the orders of magnitude discrepancy between the two different measurements (via reduced model transient electrothermal and lock-in IR thermography), this dissertation details the development of three complementary methods to accurately measure the thermal properties of the natural and synthetic Nephila (N.) clavipes spider dragline fibers. The thermal conductivity and diffusivity of the dragline silk of the N. clavipes spider has been characterized by one research group to be 151-416 W m−1 K −1 and 6.4-12.3 ×10−5 m2 s −1 , respectively, for samples with low to high strains (zero to 19.7%). Thermal diffusivity of the dragline silk of a different spider species, Araneus diadematus, has been determined by another research group as 2 ×10−7 m2 s −1 for un-stretched silk. This dissertation seeks to resolve this discrepancy by three complementary methods. The methods detailed are the transient electrothermal technique (in both reduced and full model versions), the 3ω method (for both current and voltage sources), and the non-contact, photothermal, quantum-dot spectral shape-based fluorescence thermometry method. These methods were also validated with electrically conductive and non-conductive fibers. The resulting thermal conductivity of the dragline silk is 1.2 W m−1 K −1 , the thermal diffusivity is 6 ×10−7 m2 s −1 , and the volumetric heat capacity is 2000 kJ m−3 K −1 , with an uncertainty of about 12% for each property

The BioProcessing Demonstration and Training Laboratory was established with a collaboration between Utah State University and Thermo Fisher- Scientific, Inc. This lab was developed into a fully functioning tissue culture facility. Demonstration of tissue culture procedures were necessary for the lab to be industry-fully qualified. The CHO 1-15 cell line protocols were optimized by establishing conditions for reproducibility in shaker flasks and bioreactors (2 to 250 L capacity). CHO 1-15 is the cell line of choice for protein production in the bio-manufacturing industry. Oxidative stress is a problem in the industry because it can cause a decrease in protein production. Mesobiliverdin IXα and biliverdin IXα possess antioxidant capabilities. The effects of the antioxidant nature of these compounds were tested on the CHO 1-15 cell line. Cell cultures from silkworm and spider silk producing cells were also pursued. Methods to produce a primary cell line from spider silk gland cells were developed. Cell lines from spider and silkworm silk producing glands appeared to have the capacity to secrete full-length native proteins ranging in size from 200 to 500 kDa, and possibly larger.

Spider silk has received significant attention due to its fascinating mechanical properties. Given the solitary and cannibalistic behavior of spiders, spider silk farming is impractical. Unlike spiders, silkworms are capable of producing large quantities of a fibrous product in a manner mimetic to spiders, and there already exists an industry to process cocoons into threads and textiles for many applications. The combination of silk farming (sericulture), a millennia old practice, and modern advancements in genetic engineering has given rise to an innovative biomaterial inspired by nature; transgenic silkworm silk. This project focuses on the creation of chimeric silkworm-spider silk fibers through the genetic modification of silkworms. Advanced genetic engineering techniques were used to introduce the minor ampullate spider silk (MiSp) genes into the silkworm genome. A subset of these transgenic silkworms was cross-bred with other transgenic silkworms containing the same spider silk gene in a different section of the silkworm genome to create hybrid, dual-transgenic silkworms. The transgenic silk samples showed increased mechanical properties compared to native silkworm fibers, with the strongest fibers approaching or surpassing the mechanical properties of native spider silk. The transgenic silk retained the elasticity of the native silkworm silk and gained the strength of the spider silk. Ultimately, genetic engineering opens the door to mass produce synthetic spider silk in an established organism and industry, and the results of this project demonstrate that the properties of silkworm silk can be predictably altered through this technology.

Indiana University-Purdue University Indianapolis (IUPUI) / A variety of polymers of synthetic origins (e.g., poly(ethylene glycol) or PEG) and naturally derived macromolecules (e.g., silk fibroin or gelatin) have been explored as the backbone materials for hydrogel crosslinking. Purely synthetic hydrogels are usually inert, covalently crosslinked, and have limited degradability unless degradable macromers are synthesized and incorporated into the hydrogel network. Conversely, naturally derived macromers often contain bioactive motifs that can provide biomimicry to the resulting hydrogels. However, hydrogels fabricated from a single macromer often have limitations inherent to the macromer itself. For example, to obtain high modulus PEG-based hydrogels requires an increase in macromer and crosslinker content. This is associated with an increase in radical concentration during polymerization which may cause death of encapsulated cells. Pure gelatin (G) hydrogels have weak mechanical properties and gelatin undergoes thermo-reversible physical gelation. Covalent crosslinking is usually necessary to produce stable gelatin hydrogels, particularly at physiological temperatures. The limitations of these hydrogels may be circumvented by combining them with another macromer (e.g., silk fibroin) to form hybrid hydrogels. Silk fibroin (SF) from Bombyx mori silkworms offers high mechanical strength, slow enzymatic degradability, and can easily form physical hydrogels. The first objective of this thesis was to evaluate the effect of sonication and the presence of synthetic polymer (e.g., poly (ethylene glycol) diacrylate or PEGDA) or natural macromer (e.g., gelatin) on SF physical gelation kinetics. SF physical gelation was assessed qualitatively via tilt tests. Gelation of pure SF solutions was compared to mixtures of SF and PEGDA or G, both with or without sonication of SF prior to mixing. The effect of gelatin on SF gelation was also evaluated quantitatively via real time in situ rheometry. Sonication accelerated gelation of SF from days to hours or minutes depending on SF concentration and sonication intensity. Both PEGDA and G were shown to accelerate SF physical gelation when added to SF and sonicated SF (SSF) solutions. The second objective was to develop a simple strategy to modulate covalently crosslinked PEG-based hydrogel properties by physically entrapping silk fibroin. The physical entrapment of silk fibroin provides an alternative method to increase gel storage modulus (G’) without the cytotoxic effect of increasing macromer and crosslinker concentration, or altering degradation kinetics by increasing co-monomer concentration. The effect of SF entrapment on gel physical and mechanical properties, as well as hydrolytic degradation and chemical gelation kinetics were characterized. SF physical crosslinking within the PEG-based network was shown to increase gel storage moduli by two days after gel fabrication. There was no change hydrolytic degradation rate associated with the increased moduli. SF entrapment did not affect gelation efficiency, but did alter gel physical properties. The third objective of this thesis was to develop a silk-gelatin in situ forming hybrid hydrogel for affinity-based growth factor sequestration and release and in vitro cell culture. SF provides mechanical strength and stability, whereas G contains bioactive motifs that can provide biomimicry to the gel network. Hydrogel G’ and its dependency on temperature, SF processing conditions, and secondary in situ chemical crosslinking (i.e., genipin crosslinking) were studied. Gelatin can be conjugated with heparin, a glycosaminoglycan, to impart growth factor (GF) binding affinity. Growth factor sequestration and release were evaluated in a pair of designed experiments. The hybrid gels were evaluated as substrates for human mesenchymal stem cell proliferation.

Spiders spin a wide variety of different silk types with different biological functions that are known for their extraordinary mechanical properties. Dragline silk has predominantly captured the interest of researchers because it exhibits high tensile strength and toughness while maintaining its elasticity. This thesis has focused on the characterization of a family of small molecular weight proteins recently discovered in dragline silk. These proteins were discovered in the western black widow spider, Latrodectus hesperus, and have been termed Cysteine-Rich Proteins (CRPs) due to their high conserved cysteine content. CRP family members were used in protein-protein interaction studies to determine if there is any interaction with the major ampullate spidroins (MaSps). After affinity chromatography and co-expression studies in bacteria, there were no detectable interactions between the CRPs and MaSp1. Further studies which could be an important role in the natural silk assembly process. Further protein interaction studies in different salt and pH conditions can further determine the function of the CRPs in dragline silk formation.

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The series Leipzig Kucha Studies, in which seventeen volumes are planned, aims at publishing the results of the long-term research project (2016–2030) “Buddhist Murals of Kucha on the Northern Silk Road”. The project, conducted under the auspices of the Saxon Academy of Sciences and Humanities in Leipzig, focuses on an impressive corpus of wall paintings datable to approximately the fifth to tenth centuries CE and located in the Buddhist cave complexes of the ancient kingdom of Kucha on the Northern Silk Road. These narrative and devotional paintings form one of the most important sources for our understanding of the religious and intellectual history of Buddhism in Central Asia during the first millennium. The project is devoted to recording and annotating all surviving paintings of the region, including the fragments that were removed from their original sites as well as destroyed murals from which only drawings and historical photographs remain. The project also provides a platform for research on the history of Buddhism in the Kucha region and on the spread of Buddhism from South to East Asia.

Uridine diphosphate glycosyltransferase (UGT) is a multigene family of enzymes responsible for catalyzing glycosylation of small hydrophobic molecules. Recently, a genomic analysis of the corn earworm (Helicoverpa zea) identified 45 different UGT genes. We discovered a UGT gene (UGT34) showing high levels of expression exclusively in the silk gland tissue. The expression levels of UGT34 were analyzed in different developmental stages and silk gland sub-segments, revealing that UGT34 is generally expressed at all larval instar stages and largely expressed in the middle and posterior subsegments of the silk glands. The soybean looper (Chrysodeixis includens), another noctuid moth species, was analyzed and found to have similar gene expression patterns. To determine UGT34 function RNA interference (RNAi) was used, but it revealed to be unsuccessful. Taken together, the present study implies that UGT34 plays an important role in silk glands, yet its molecular and physiological function needs to be determined by further study.

Through translations and transformations, my degree project aims to explore what makes something – space, or an object– charged. I am investigating ways to create objects with the starting point in two pieces of furniture, analyzing them both in their everyday contexts, and in certain works of art. This has resulted in the creation of two works that I have called an imprint and a bench and a bed. The quality that I have been searching for in this project is what activates a subjective feeling of recognition that will stay in the mind of the beholder, a charge in an object that affects memory or consciousness. The way I explore this quality is by analyzing the terms Eros and punctum and by investigating the relationship between the abstract and the figurative, examining the bodily connection to the objects and the surrounding.