In nature, organisms have long been able to create elaborate mineral structures at ambient temperatures. From a materials science and engineering perspective, favorable properties emerge when the synthesis process can be controlled at finer levels. New strategies in materials chemistry synthesis has been inspired by biomineralization: biomimetics. In this work, silk fibroin films were used to synthesize gold nanoparticles room temperature by soaking a free standing 15nm silk film in HAuCl4. Particles ranged in size and shape from 5nm spheres to 105nm hexagons. Secondly, a film of ZnO1 peptide (ZnO selectively binding peptide) was successfully formed by drop casting on both silk and polystyrene surfaces. Using a HMT + Zn(NO3)2 system for ZnO wet chemical deposition, rods were formed on the peptide surface. Changing solution concentration and growth time affected the density and size of the nanorods. Spin coating a 3nm peptide film reduced the roughness to <1nm, upon which an array of vertical ZnO rods with controllable density was synthesized.

In our study, the superhydrophobic surface based on biomimetic lotus leave is explored to maintain the desired properties for self-cleaning. In controlling bead-up and roll-off characteristics of water droplets the contact angle and contact angle hysteresis were very important and we investigated the determining conditions on different model surfaces with micro- and nanostructures. Two governing equations were proposed, one for contact angle based on Laplace pressure and one for contact angle hysteresis based on Young-Dupré equation. Based on these understanding on superhydrophobicity, possible applications of the superhydrophobicity for self-cleaning and water repellency were explored and application related technical issues were addressed. Based on our understanding of the roughness effect on superhydrophobicity (both contact angle and hysteresis), structured surfaces from polybutadiene, polyurethane, silica, and Si etc were successfully prepared. For engineering applications of superhydrophobic surfaces, stability issues regarding UV, mechanical robustness and humid environment need to be investigated. Among these factors, UV stability is the first one to be studied. Silica surfaces with excellent UV stability were prepared. UV stability on the surface currently is 5,500 h according the standard test method of ASTM D 4329. No degradation on surface superhydrophobicity was observed. New methods for preparing superhydrophobic and transparent silica surfaces were investigated using urea-choline chloride eutectic liquid to generate fine roughness and reduce the cost for preparation of surface structures. Another possible application for self-cleaning in photovoltaic panels was investigated on Si surfaces by construction of the two-scale rough structures followed by fluoroalkyl silane treatment. Regarding the mechanical robustness, epoxy-silica superhydrophobic surfaces were prepared by O2 plasma etching to generate enough surface roughness of silica spheres followed by fluoroalkyl silane treatment. A robustness test method was proposed and the test results showed that the surface is among the most robust surfaces for the superhydrophobic surfaces we prepared and currently reported in literature.

Current orthopedic implant technologies used suffer from slow rates of osseointegration, short lifetime, and lack of mechanical integrity as a result of poorly controlled cell-surface interactions. Recent biologically-inspired surface strategies (biomimetic) have focused on mimicking the biofunctionality of the extracellular matrix (ECM) by using short, adhesive oligopeptides, such as arginine-glycine-aspartic acid (RGD) present in numerous ECM components. However, these strategies have yielded mixed results in vivo and marginal bone healing responses. The central goal of this dissertation project was to engineer bioactive surfaces that specifically target integrin receptors important for osteogenic functions in order to improve bone tissue repair. In order to create integrin-specific interfaces, integrin-specific ligands reconstituting the fibronectin (FN) secondary/tertiary structure were first engineered and functionalized on material surfaces using several robust presentation schemes. We demonstrated that FN-mimetic-functionalized surfaces that directed α5β1 binding enhanced osteoblast and stromal cell integrin binding and adhesion, osteogenic signaling, and osteoblastic differentiation compared to various other RGD-based ligand-functionalized surfaces. Next, we investigated the effect of integrin-specific biointerfaces to modulate bone healing in a rat tibia implant bone model. We demonstrated, using a robust polymer brush system, that bioactive coatings on titanium implants that conferred high α5β1 integrin specificity in vitro enhanced bone formation and implant integration in vivo. Moreover, we showed that integrin specificity can be engineered using different immobilization schemes, including clinically-relevant ligand dip-coating, and promote the same robust in vivo effect. Furthermore, we investigate the synergistic roles of integrin specificity and ligand clustering on cell response by engineering biointerfaces presenting trimeric and pentameric "heads" of FNIII7-10 with nanoscale spacing. Integrin-specific ligand clustering supported α5β1-specific binding and cell adhesion and enhanced implant osseointegration in vivo compared to monovalent FNIII7-10 or non-functionalized biointerfaces. In summary, the FN-mimetic integrin-specific biointerfaces engineered in this thesis provide a clinically-relevant material surface strategy to modulate tissue healing responses. In addition, these results contribute to our greater understanding of how two specific material design parameters, integrin binding specificity and clustered ligand presentation, contribute individually and synergistically toward directing cell and tissue function.

Biomimetic peptides are autonomously folding secondary structural units designed to serve as models for examining processes that occur in proteins. Although de novo biomimetic peptides are not simply abbreviated versions of proteins already found in nature, designing biomimetic peptides does require an understanding of how native proteins are formed and stabilized. The discovery of autonomously folding fragments of ribonuclease A and tendamistat pioneered the use of biomimetic peptides for determining how the polypeptide sequence stabilizes formation of alpha helices and beta hairpins in aqueous and organic solutions. A set of rules for constructing stable alpha helices have now been established. There is no exact set of rules for designing beta hairpins; however, some factors that must be considered are the identity of the residues in the turn and non-covalent interactions between amino acid side chains. For example, glycine, proline, aspargine, and aspartic acid are favored in turns. Non-covalent interactions that stabilize hairpin formation include salt bridges, pi-stacked aromatic interactions, cation-pi interactions, and hydrophobic interactions. The optimal strand length for beta hairpins depends on the numbers of stabilizing non-covalent interactions and high hairpin propensity amino acids in the specific peptide being designed. Until now, de novo hairpins have not previously been used to examine biological processes aside from protein folding. This thesis uses de novo designed biomimetic peptides as tractable models to examine how non-covalent interactions control the redox properties of tyrosine in enzymes. The data in this study demonstrate that proton transfer to histidine, a hydrogen bond to arginine, and a pi-cation interaction create a peptide environment that lowers the midpoint potential of tyrosine in beta hairpins. Moreover, these interactions contribute equally to control the midpoint potential. The data also show that hydrogen bonding is not the sole determinant of the midpoint potential of tyrosine. Finally, the data suggest that the Tyr 160D2-Arg 272CP47 pi-cation interaction contributes to the differences in redox properties between Tyr 160 and Tyr 161 of photosystem II.

Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Scott, David; Committee Member: Kurtis, Kimberly; Committee Member: Work, Paul. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (Ph.D.)--University of Melbourne, School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, 2010. / Typescript. Includes bibliographical references (p. 183-213)

A indústria da construção civil é conhecida como umas das atividades econômicas que causam os maiores impactos ambientais desde o processo de extração da matéria prima até a produção dos produtos, incluindo o transporte e manutenção do ambiente construído. A produção de um dos seus principais componentes, o cimento, é o maior contribuinte para a emissão de gases de efeito estufa, principalmente devido a queima de combustíveis fósseis. Por este motivo, pesquisas na área de biotecnologia sustentável são conduzidas para diminuir e até mitigar os efeitos danosos provocados pelos fatores que compõem a construção civil. Dentre estas pesquisas destacam-se as que se baseiam na Biomimética, que é uma ciência que busca na Natureza as soluções tecnológicas para os problemas que os desenvolvimentos humanos geralmente apresentam: a geração de resíduos poluentes, uso de produtos químicos tóxicos e processos que operam com energia e pressão elevadas. Com base nos conceitos biomiméticos, este trabalho se propôs a estudar a biomineralização, que é um processo que ocorre na Natureza a milhares de anos e é responsável pela formação de muitas estruturas biomineralizadas tanto no ambiente terrestre como aquático. A biomineralização é um fenômeno provocado pela ação de diversas espécies de microrganismos que durante o processo de obtenção de energia reciclam minerais presentes no solo e na água e os precipitam na forma de sais inorgânicos. Este material precipitado age como agente ligante de partículas como no caso de formações geológicas (estromatólitos) ou exoesqueletos de animais marinhos, por exemplo. Neste estudo foi avaliado a biomineralização por biodeposição de carbonato de cálcio precipitado na presença da espécie de bactéria ureolítica (Bacillus subtilis) em ensaios em escala laboratorial utilizando corpos de prova de areia, argamassa e concreto. Os corpos de prova em areia e argamassa foram observados em MEV e EDS permitindo a identificação de células de microrganismos, formação de biofilme e provável formação de cristais de carbonato de cálcio na região de biofilme. Os corpos de prova de concreto foram utilizados para avaliar as consequências da biodeposição na absorção de água por capilaridade do material. Resultados indicam redução de 20% na absorção de água por capilaridade. Com os resultados obtidos é possível concluir que a técnica de biodeposição pode ser uma alternativa ao tratamento superficial de estruturas de concreto, contudo requer estudos posteriores de aplicação técnica e viabilidade econômica. / The construction industry has been known as one of the economic activities that cause the major environment impacts since the process of raw material extraction until the products manufacturing including transport and maintenance of the built environment. The production of one of the main compounds, the cement, is the largest contributor to the greenhouse gas emissions, mainly due to burn fossil fuels. For this reason, researches in sustainable biotechnological area are conducted to minimize and even mitigate the damaging effects either promoted by construction industry factors. Among these ones, it stands out researches based on Biomimetic, which is a science that seeks in Nature the technological solutions for problems that human’s development usually presents: the generation of pollutant residues, the use of toxic chemicals and process that operates in high pressure and energy. Based on biomimetic concepts this research proposes to study the biomineralization, which is a process that has occurred in the Nature for thousands of years and it is responsible for the formation of many structures either in soil and water environments. The biomineralization is a phenomenon caused by several specimens of microorganisms that during the process of obtaining energy, they recycle minerals presents at soil and water inducing precipitation as inorganic salts. This precipitated material works as a binder of particles similar to geologic formations (stromatolites) or exoskeleton of sea animal for example. In this study the biomineralization was evaluated through biodeposition of precipitated calcium carbonate by specimen of ureolytic bacteria (Bacillus subtilis). Essays were held using samples made by sand, mortar and concrete. The samples made by sand and mortar were observed at MEV and EDS, allowing the identification of microorganism cells, biofilm formation and probable formation of calcium carbonate crystals at biofilm region. The concrete samples were used to evaluate the consequences of biodeposition on water absorption by capillarity of the material. The results show reduction of 20% on water absorption by capillarity. According the results achieved it possible to conclude that the biodeposition technique can be an alternative to superficial treatment for concrete structures. However, it will be required more studies to evaluate technical application and economical availability.

A indústria da construção civil é conhecida como umas das atividades econômicas que causam os maiores impactos ambientais desde o processo de extração da matéria prima até a produção dos produtos, incluindo o transporte e manutenção do ambiente construído. A produção de um dos seus principais componentes, o cimento, é o maior contribuinte para a emissão de gases de efeito estufa, principalmente devido a queima de combustíveis fósseis. Por este motivo, pesquisas na área de biotecnologia sustentável são conduzidas para diminuir e até mitigar os efeitos danosos provocados pelos fatores que compõem a construção civil. Dentre estas pesquisas destacam-se as que se baseiam na Biomimética, que é uma ciência que busca na Natureza as soluções tecnológicas para os problemas que os desenvolvimentos humanos geralmente apresentam: a geração de resíduos poluentes, uso de produtos químicos tóxicos e processos que operam com energia e pressão elevadas. Com base nos conceitos biomiméticos, este trabalho se propôs a estudar a biomineralização, que é um processo que ocorre na Natureza a milhares de anos e é responsável pela formação de muitas estruturas biomineralizadas tanto no ambiente terrestre como aquático. A biomineralização é um fenômeno provocado pela ação de diversas espécies de microrganismos que durante o processo de obtenção de energia reciclam minerais presentes no solo e na água e os precipitam na forma de sais inorgânicos. Este material precipitado age como agente ligante de partículas como no caso de formações geológicas (estromatólitos) ou exoesqueletos de animais marinhos, por exemplo. Neste estudo foi avaliado a biomineralização por biodeposição de carbonato de cálcio precipitado na presença da espécie de bactéria ureolítica (Bacillus subtilis) em ensaios em escala laboratorial utilizando corpos de prova de areia, argamassa e concreto. Os corpos de prova em areia e argamassa foram observados em MEV e EDS permitindo a identificação de células de microrganismos, formação de biofilme e provável formação de cristais de carbonato de cálcio na região de biofilme. Os corpos de prova de concreto foram utilizados para avaliar as consequências da biodeposição na absorção de água por capilaridade do material. Resultados indicam redução de 20% na absorção de água por capilaridade. Com os resultados obtidos é possível concluir que a técnica de biodeposição pode ser uma alternativa ao tratamento superficial de estruturas de concreto, contudo requer estudos posteriores de aplicação técnica e viabilidade econômica. / The construction industry has been known as one of the economic activities that cause the major environment impacts since the process of raw material extraction until the products manufacturing including transport and maintenance of the built environment. The production of one of the main compounds, the cement, is the largest contributor to the greenhouse gas emissions, mainly due to burn fossil fuels. For this reason, researches in sustainable biotechnological area are conducted to minimize and even mitigate the damaging effects either promoted by construction industry factors. Among these ones, it stands out researches based on Biomimetic, which is a science that seeks in Nature the technological solutions for problems that human’s development usually presents: the generation of pollutant residues, the use of toxic chemicals and process that operates in high pressure and energy. Based on biomimetic concepts this research proposes to study the biomineralization, which is a process that has occurred in the Nature for thousands of years and it is responsible for the formation of many structures either in soil and water environments. The biomineralization is a phenomenon caused by several specimens of microorganisms that during the process of obtaining energy, they recycle minerals presents at soil and water inducing precipitation as inorganic salts. This precipitated material works as a binder of particles similar to geologic formations (stromatolites) or exoskeleton of sea animal for example. In this study the biomineralization was evaluated through biodeposition of precipitated calcium carbonate by specimen of ureolytic bacteria (Bacillus subtilis). Essays were held using samples made by sand, mortar and concrete. The samples made by sand and mortar were observed at MEV and EDS, allowing the identification of microorganism cells, biofilm formation and probable formation of calcium carbonate crystals at biofilm region. The concrete samples were used to evaluate the consequences of biodeposition on water absorption by capillarity of the material. The results show reduction of 20% on water absorption by capillarity. According the results achieved it possible to conclude that the biodeposition technique can be an alternative to superficial treatment for concrete structures. However, it will be required more studies to evaluate technical application and economical availability.

La bio-inspiration applique des principes et des stratégies issus de systèmes biologiques afin de faciliter la conception technologique. Doté d’un fort potentiel pour l’Innovation, la biomimétique, son pendant méthodologique, est en passe d’évoluer vers un processus clé pour les entreprises. Un certain nombre de freins demeurent cependant à lever afin que la conception bio-inspirée s’apparente à une démarche robuste et répétable. Les travaux réalisés abordent cette diffusion de la conception bio-inspirée selon deux axes distincts. Ils s’efforcent tout d’abord d’harmoniser champs conceptuels relatifs à la bio-inspiration et modèles de processus biomimétiques, en vue de rendre possible l’évaluation des outils supportant cette démarche de conception. Cette évaluation méthodologique, couverte selon l’angle objectif et subjectif, aboutit à la formalisation d’un modèle structurant, un arbre de classification, à même de guider les concepteurs biomimétiques à travers le processus biomimétique. En parallèle de l’établissement de ce cadre de référence méthodologique, les travaux s’évertuent à explorer un autre verrou inhérent à la démarche : l’interaction entre biologie et ingénierie. Les travaux tendent ainsi, par le développement d’un outil, à réduire l’une des barrières d’entrée de ce type d’approche, en proposant un modèle décrivant fonctionnellement les systèmes biologiques sans prérequis d’expertise biologique. La concaténation de ces réalisations aborde directement l’enjeu principal de ce champs disciplinaire : son essor par la dissémination de son application à l’innovation industrielle, en vue de favoriser l’émergence de « produits biomimétiques » au détriment des « accidents bio-inspirées ». / Biomimetics applies principles and strategies which stem from biological systems in order to facilitate technological design. Providing a high innovation potential, biomimetics could become a key process for various business. However, there are still a few challenges to overcome in order for the bioinspired design to become a sustainable approach. The work which has been carried out addresses this bioinspired design diffusion with two distinct focuses. First of all, they tend to standardize conceptual fields for bio-inspiration and biomimetic process models to enable the evaluation of tools supporting said design process. This methodological assessment, addressed from an objective and subjective point of view, results in the formalization of a structuring model, a classification tree which guides designers through the biomimetic process. Alongside the development of this methodological reference framework establishment, the work tends to overcome another obstacle of the bioinspired design implementation which is the interaction between biology and engineering. By developing a specific tool, the research studies offer a model which functionally describes biological systems without biological expertise prerequisites. The concatenation of these accomplishments addresses the main issue of these disciplinary fields: its development through the dissemination of its application to industrial innovation, in order to encourage the emergence of “biomimetic products” at the expense of “bio-inspired accidents”.

Human esophageal squamous cell carcinoma (hESCC) is a very aggressive form of cancer due to its ability to easily metastasize into proximal lymph nodes and adjacent organs. The role of the extracellular matrix (ECM) and its stromal cells in metastasis remains unclear. To better understand the effect of the ECM and fibroblast cells on esophagus cancer cell migration and invasion, we propose a biomimetic human esophagus model cultured with hESCC and human primary fibroblast cells (fibroblast). To mimic the extracellular matrix of human esophagus we use decellularized porcine esophagus matrix (DEM) to culture with hESCC and fibroblasts in static conditions. This DEM can recapitulate the human esophagus tumor microenvironment with relevant cues. This model will provide valuable information regarding esophagus cancer cell migration with respect to the heterogeneous extracellular matrix and stromal fibroblast cells. We expect to discover the mechanisms by which extracellular matrix and stromal cells affect cancer migration and invasion in vitro. Characterizing this process will provide vital insight towards the effects of fibroblasts cells on facilitating migration and invasion of esophageal cancer cells. This esophagus cancer model also provides promising potential to study drug screening and develop new strategies against esophagus metastasis. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection