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Getie, Kebtie Melkamu. "Mass spectrometric characterization of elastin peptides and the effect of solar radiation on elastin." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=980155932.
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Bhanji, Tania. "Elastin in zebrafish and mice." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=111938.
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The extracellular matrix is a vital component of the cardiovascular system, in that, it not only provides structural support but also plays a critical role in the maintenance of cellular stability. One of the major components of the vascular matrix is elastin, which confers vessels with the specialized property of stretch and recoil. Elastin deficiency has been implicated in many vascular diseases and determined experimentally to be a negative regulator of smooth muscle cell proliferation. In zebrafish, two elastin genes have been identified, which are actively expressed during development. Based on this finding, protein production and spatial localization for the two elastin proteins was studied by immunohistochemistry with specific antibodies. Results revealed a global distribution for elastin 1 in the ventral aorta and swim bladder, whereas elastin 2 was preferentially localized to the bulbus arteriosus indicating a possible specialized function of elastin 2 in this structure. This observation, and the unique physiological property of this structure, suggests a possible reason for the preservation of both elastin genes during evolution.In the second part of this study, elastin-null mice were studied to uncover the impact of the loss of elastin on the expression of other elastic fiber-associated proteins. The expression of fibrillin-1, the major component of microfibrils, was not altered in the absence of elastin, implying that elastin is not necessary for the formation of microfibrils. On the other hand, both fibulin-2 and -5 were upregulated in the absence of elastin, suggesting that expression of these genes are controlled by elastin. Overall, this study highlights the importance of elastin in evolution, as well as its potential role in the regulation of expression of other matrix molecules.
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Ferron, Florence Joelle. "The implications of fibulin-5 on elastin assembly and its role in the elastic fiber /." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101846.
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The extracellular matrix (ECM) is the material found surrounding the cells in a tissue. One component of the ECM is the elastic fiber, which confers the property of elasticity to its environment. Organs such as the lung, skin and major blood vessels have an abundance of elastic fibers so that they are able to expand and recoil. Elastic fibers are composed of two main components; elastin and microfibrils. Microfibrils are composed primarily of fibrillin-1 and provide a scaffold unto which tropoelastin monomers assemble. Elastic fibers interact with many other proteins in the ECM, one of which is fibulin-5. Based on the severe elastic fiber defects observed in the fibulin-5 null mouse, it was established that fibulin-5 plays an essential role in elastic fiber development. This role may be in the deposition of tropoelastin onto microfibrils and/or in stabilizing the elastic fibers in the extracellular matrix. In the present study, the relationship between fibulin-5 and the elastic fiber was investigated through a number of in vivo and in vitro experiments. To test the hypothesis that fibulin-5 requires the presence of elastin to assemble in the ECM, full-length recombinant fibulin-5 (rF5) was purified from transfected cells and used to make a fibulin-5 antibody. Solid-phase binding assays using rF5 showed that fibulin-5 binds tropoelastin at two sites; the initial portion of the C-terminus and the first calcium-binding epidermal growth factor-like domain at the N-terminus. Immunofluorescence staining of elastin null mouse embryonic fibroblast cultures revealed that fibulin-5 does not require elastin to be present in the ECM in order to assemble. Subsequently, solid-phase binding assays showed that fibulin-5 can bind to the N-terminus of fibrillin-1. To determine if fibulin-5 could exist independent of elastin and/or fibrillin-1 in vivo, an immunohistochemical analysis was conducted on heart, liver, lung, colon, spleen, testis and kidney. All three proteins were co-localized in all organs except in the kidney, where fibrillin-1 was found to independently stain the capillary tufts of the renal corpuscles and renal tubules. Thus, fibulin-5 may be co-regulated with elastin and is not present on elastin-independent microfibrils. Additionally, novel locations of elastic fibers were uncovered in the heart, liver, colon, spleen and testis. Overall, this study provides important insights as to the role of fibulin-5 in elastic fiber structure and assembly and also reveals the complexity in understanding the pathogenesis of diseases involving elastic fiber proteins.
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Moore, Glynis Wilson. "Human aortic elastin : an examination of elastic lamellae fragmentation associated with ageing and atherosclerosis." Thesis, Queen's University Belfast, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356892.
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Dillon, Tara J. "Elastin metabolisim in human lung disease /." Title page, contents and abstract only, 1994. http://web4.library.adelaide.edu.au/theses/09PH/09phd5793.pdf.
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Smith, Kinley. "The distribution and function of elastin and elastic fibres in the canine cruciate ligament complex." Thesis, University of Liverpool, 2010. http://livrepository.liverpool.ac.uk/1437/.
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Anterior cruciate ligament rupture (ACL) is a major source of morbidity in the dog, leading to severe osteoarthritis of the knee joint and marked lameness. Following rupture, the ACL will not heal and in the dog, ACL rupture is thought to be the end stage of degenerative ligament disease (non-contact ACL injury). The extracellular matrix (ECM) of CLs has been extensively studied but little is known of the role of elastic fibres in the physiology of the ECM, the mechanics of CL function and in CL degeneration. Elastic fibres include polymers of fibrillins (microfibrils), bundles of microfibrils (oxytalan fibres) and elastin fibres (bundles of microfibrils with an elastin core). The hypothesis of this thesis is that elastin has a mechanical and a biological role in the canine cruciate ligament complex. It is further hypothesised that the distribution and function of elastic fibres will vary between three breeds of dog with differing risk of ACL rupture are: the greyhound with a low risk, the beagle with a low-to-moderate risk and the Labrador retriever with a high risk. The distribution of elastic fibres, fibrillins and cells was investigated throughout the CL complex using a combination of histochemical staining and immunofluorescence. CL microanatomy was studied using Nomarski differential interference microscopy. Elastin was measured biochemically and compared to histologic assessment of tissue architecture, elastic fibre staining and other biochemical parameters. The biological effect of elastin degradation products (EDPs) was assessed in an in vitro ACL cell culture model. A low risk dog breed to ACL rupture (greyhound) was used in all investigations and comparisons were made with other breeds with regard to cellular and elastic fibre anatomy. Differences in cell morphology between breeds with differing risk of ACL rupture may reflect fundamental differences in CL physiology possibly through altered cell-to-cell communication. Cellular and matrix changes, considered degenerative, were seen throughout the CL complex and may reflect adaptation rather than degeneration in certain dog breeds such as the greyhound. Elastin content ranged from 5.9 to 19.4% of ligament dry weight. This was a far greater proportion of canine CLs than previously. Elastin fibres may have a mechanical role in bundle reorganization following ligament deformation. The distribution of fibrillins 1 and 2 was different from the pattern previously reported in tendon and may represent a fundamental difference between ligament and tendon. In the greyhound CL there was a significant proportional increase in oxytalan fibre staining with advancing CL degeneration. This response was seen also in the Labrador retriever and the beagle but the increase in oxytalan fibre staining was less marked with advancing degeneration. Therefore production of oxytalan fibres may reflect a healing response in damaged CL tissue in breeds at a low risk of ligament rupture. Fragments of elastin containing the VGVAPG motif affect canine ACL cells in vitro resulting in increased transcription of fibrillin 2 mRNA. Additionally, there was synergism with TGF-β1 resulting in upregulation of the elastin laminin receptor 1, through which EDPs are transduced. EDPs may thus have a role in response to injury in the CL.
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Chevallier, Stéphane. "Elastokines et Lactosylcéramide : cardioprotection et vieillissement." Thesis, Reims, 2011. http://www.theses.fr/2011REIMM203/document.
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La maladie cardiovasculaire la plus courante dans les pays industrialisés est la maladie coronarienne responsable d’une ischémie du tissu cardiaque pouvant conduire à l’infarctus du myocarde. Bien que les améliorations de la prise en charge aient considérablement réduit les délais de la reperfusion (seul remède à l’ischémie), l’ischémie/reperfusion (I/R) entraîne des dommages cellulaires et tissulaires ainsi qu’une diminution des capacités fonctionnelles du coeur. Il existe néanmoins des systèmes de cardioprotection endogènes (comme le préconditionnement (préC) ou le postconditionnement (postC)) que l’on peut activer via l’administration de substances pharmacologiques. L’élastine, une protéine fibreuse de la matrice extracellulaire, est responsable de l’élasticité de certains de nos tissus (poumons, peau, <). Des peptides issus de la dégradation de l’élastine (PE) exercent un effet cardioprotecteur envers l’I/R en activant la voie de survie cellulaire RISK. Dans des fibroblastes dermiques, la transduction du signal induit par les peptides d’élastine est médiée de façon précoce par un second messager : le lactosylcéramide (LacCer). Cette étude constitue une première approche des effets du LacCer dans la cardioprotection envers l’I/R. Nous avons montré que le LacCer est un médiateur précoce du signal cardioprotecteur induit par les PE et qu’il protège le coeur des dommages liés à l’I/R dans un modèle de coeur isolé et perfusé en postC. Lors du vieillissement, de nombreuses modifications physiologiques sont à l’origine d’une perte d’efficacité des mécanismes de cardioprotection. Dans ce travail, nous avons également étudié les effets cardioprotecteurs des PE, du LacCer et de l’inhibition de p38MAPK (une protéine probablement impliquée dans la perte des mécanismes cardioprotecteurs liée au vieillissement) envers les dommages liés à l’I/R chez les rats âgés. Nous avons montré que les PE exercent un effet cardioprotecteur en pré+postC contre l’I/R au niveau de la survie cellulaire et au niveau de la récupération des capacités contractiles cardiaques. Le LacCer n’exerce un effet protecteur qu’au niveau de la survie cellulaire et l’inhibition de p38MAPK entraine une meilleure récupération des capacités contractiles sans améliorer la survie cellulaireIn developed countries the most common cardiovascular disease is coronary heart disease that is responsible for myocardial ischemia and can lead to myocardial infarction. Reperfusion is the only cure for ischemia. Care improvement has dramatically reduced reperfusion delay but ischemia/reperfusion (I/R) causes a lot of cellular and tissular damages and a reduction of cardiac contractile abilities. Nevertheless cardioprotective pathways (like preconditionning (preC) and postconditionning (postC) can be pharmacologically triggered to reduce I/R injury. Elastin is a fibrous protein from extracellular matrix and is responsible for tissues elasticity in lungs, skin, < Peptides derived from elastin fragmentation (EP) exhibit cardioprotective function against I/R by triggering the RISK pathway, a cell survival pathway. In dermic fibroblasts, elastin peptides pathway is mediated by an early messenger : lactosylcéramide (LacCer). In this work we have studied cardioprotective function of LacCer against I/R injury. We show that LacCer is an early messenger of EP cardioprotective pathway and that it also exhibits a cardioprotective function against I/R in an postconditionning isolated rat heart model. During ageing dramatic physiological modifications are responsible for a loss of efficiency of cardioprotection pathways. In this work we have also studied the potential cardioprotective function of EP, LacCer and p38MAPK inhibition (a protein presumably involved in loss of efficiency of cardioprotection pathways during ageing) against I/R injury in aged rats. We have shown that EP exhibit a cardioprotective function against I/R injury in aged rats as well as young rats in a pre+postconditionning protocol. EP enhance contractile abilities recovering and cell survival. LacCer improves only cell survival and p38MAPK inhibition improves only contractile abilities recovering
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Chalmers, Gavin William Geddes. "A comparative study of the swelling and mechanical properties of vertebrate elastins." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27856.
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The swelling-temperature compensation hypothesis as proposed by Gosline and French (1979) is examined by investigating the physical and mechanical properties of an evolutionary series of vertebrate elastins.
Temperature-dependent swelling, low water contents and thermodynamics typical of hydrophobic systems were observed for all elastins except salmon. Salmon elastin, on the other hand, showed temperature-independent swelling and a high water content. Thermodynamic analysis showed that salmon elastin still contained a hydrophobic component. The swelling-temperature compensation hypothesis suggests that the extreme hydrophobic nature of elastin evolved in order to provide the proteins with temperature-dependent swelling and thus, maintaining elastic efficiency over a wide temperature range. All elastins should then be very hydrophobic systems which is inconsistent with the physical chemical results. All vertebrate elastins are not necessarily hydrophobic systems since salmon elastin shows no temperature-dependence to its swelling.
The efficiency of a series of vertebrate elastins was measured over 0 to 60°C temperature range using a forced vibration technique. Over a wide frequency range, both lower and higher vertebrate elastins were capable of efficient spring-like behaviour. Both a higher vertebrate, with temperature-dependent swelling, and a lower vertebrate, with no temperaturate-dependence to its swelling, showed elastic efficiency. The swelling-temperature compensation hypothesis must be rejected.Science, Faculty of
Zoology, Department of
Graduate
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Georgilis, Evangelos. "Engineering of Thermoresponsive Diblock Elastin-like Polypeptides." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0444.
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La thèse présentée porte sur l’ingénierie de diblocs de polypeptides à base de motifs élastine (ELPs) susceptibles de s’auto-assembler sous forme de nanoparticules après modification chimique de certains résidus. La stratégie inclue le développement de diblocs d’ELPs composés d’un bloc hydrophobe comportant l’isoleucine en position hôte, fusionné à l’extrémité N-terminale avec un bloc contenant des résidus méthionine chimiosélectivement modifiables. Des modifications du groupement thioéther permettent en effet l’hydrophilisation du segment ELP correspondant ainsi que l’introduction de groupements réactifs. Une première génération d’ELPs diblocs a été développée par génie génétique, production recombinante chez Escherichia coli et caractérisée. Le résidu cystéine à l’extrémité C-terminale a été modifié pour contrôler la monodispersité et introduire des fluorochromes, tandis que les résidus méthionine ont été modifiés pour changer l’équilibre hydrophile/hydrophobe et introduire des groupements réactifs. L’auto-assemblage des diblocs non-modifiés et post-modifiés a été étudiée par des mesures de turbidité et diffusion dynamique de la lumière. Ces méthodes ont mis en évidence une transition thermale de chaînes solubles en agrégats de taille micronique. Pour permettre la formation particules de taille nanométrique, une deuxième génération d’ELPs diblocs a été conçue grâce à l’application d’un modèle empirique. La deuxième génération d’ELPs diblocs forme effectivement des nanoparticules après modification chimiosélective des résidus méthionines. Ces structures pourront potentiellement contribuer au développement de nanoformulations à base d’ELPsThe present work focuses on the engineering of diblock elastin-like polypeptides (ELPs) that thermally assemble into nanostructures after the application of chemical modifications. The strategy involved the development of diblock ELPs composed of a hydrophobic isoleucine-containing block fused at its N-terminal end to a block containing residues amenable to chemoselective modifications, namely methionine. This particular residue was employed because the orthogonal modification of its thioether group allows for the change of the hydrophilic/lipophilic balance of the diblock ELP and the possible simultaneous grafting of functional ligands. A first generation of diblock ELPs was therefore designed by means of molecular clonings, produced in E. coli, and characterized by chemical methods to further monitor post-modifications. The chemical modifications were applied at the C-terminal cysteine to control the system monodispersity and introduce fluorescent probes, and also at methionine in order to change the hydrophilic/lipophilic balance and introduce reactive groups. The self-assembly of the non-modified and post-modified ELPs was monitored by means of turbidimetry, nanoparticle tracking analysis and dynamic light scattering, which showed that these sequences possessed a transition from monomers to aggregates. To access nanoparticle formation, a second generation of diblock ELPs was developed, the design of which was based on theoretical modeling. The second generation diblocks self-assembled into nanoparticles by means of methionine post-modifications. It is expected that these sequences will contribute to the development of diblock ELP-based nano-formulations
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Alanazi, Hamdan Noman. "Characterization of Elastin-Like Polypeptides Using Viscometry." Cleveland State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=csu1311026986.
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Green, Ellen Marie. "Mechanisms of elasticity in elastic proteins." Thesis, University of Exeter, 2012. http://hdl.handle.net/10036/4058.
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This thesis investigates the mechanical properties of the elastic proteins isolated by cyanogen bromide digestion from lamprey cartilages and compares them with the mammalian protein, elastin. Thermomechanical testing and measurements of the effects of hydrophobic solvents on mechanics are used to determine the energetic and entropic contributions to the mechanical properties and the role of solvent interactions. Raman microspectrometry is shown to be a valuable tool in determining the secondary structure of the proteins, their interactions with water and molecular-level effects of mechanical strain. The supramolecular structure of the proteins matrices are investigated using nonlinear microscopy and X-ray diffraction. The mechanical properties of fibrous elastin agreed with those previously reported with elastic moduli in the region of 0.2-0.4 MPa. Elastic moduli decrease by approximately 25% with increased temperature, which was accompanied by a small decrease in hysteresis loss. In agreement with earlier findings, an entropic mechanism of elasticity became dominant only at high temperatures with a major contribution from interactions with solvent water. The lamprey proteins can be divided into two broad groups, the 'soft' branchial and pericardial cartilages resembling elastin, with linear stress-strain behaviour over a range of strains, elastic moduli in the range 0.13 MPa to 0.35 MPa, breaking strains of up to 50% and low hysteresis. Annular and piston proteins showed a very different response having much higher elastic moduli (0.27 MPa to 0.75 MPa), higher breaking strains and large hysteresis. Similarities between elastin and the lamprey matrix proteins extended to their thermomechanical behaviour with a decrease in elastic moduli and a drive towards entropic elasticity at high temperatures, although the annulus and piston were less thermally stable. Raman spectroscopy was able to detect differences between the various proteins and between elastin fibres and fragmentation products. Although no vibrational modes associated with cross-linking of the fibres could be identified, the secondary structure of dehydrated fibrous elastin was significantly different from \alpha -elastin. The former differed from previous experimental measurements, but was close to the theoretical predictions with 36% \beta -structures, 46% unordered and 18% \alpha -helix. \alpha -Elastin contained 29% \beta -structures, 53% unordered and 18% \alpha -helix. Strains of up to 60% in ligament fibre bundles resulted in no significant shifts in peak positions or in secondary structure. Polarization measurements revealed that the peptide bonds and several of the bulky side-chains re-orientated closer to the fibre axis with strain. Heating nuchal elastin fibres to 60^{\circ} C to increase the energetic component of the elasticity was associated with a 30% increase in the proportion of \beta -structures in the amide I band, a 50% increase in the amide III band, and a 50% reduction in the signal from bound water. The Raman spectra of the lamprey matrix proteins are similar both to each other and when compared to fibrous elastin. Only small differences could be detected in side-chain modes consistent with reported biochemical differences. Decomposition of the amide I band indicated that the secondary structures were also very similar to that of elastin, with a preponderance of unordered structures which probably confer the high degree of conformational flexibility necessary for entropy elasticity. Piston and annular proteins, like elastin, showed a strong interaction with water, suggesting a greater role of hydrophobic interactions in their mechanics compared to the branchial and pericardial proteins. Elastin is well known to exhibit autofluorescence. However, only the branchial protein has been reported to autofluoresce. This study shows that all four lamprey matrix proteins investigated exhibit strong autofluorescence which was subsequently exploited to image these tissues using multiphoton microscopy. Microscopic investigations revealed that the architecture of lamprey proteins differ from that of elastin. Nuchal elastin forms bundles of fibres running predominantly parallel to the direction of applied force. The arrangement in lamprey cartilage is very different forming honeycomb structures, which in the case of annular and piston cartilages, is surrounded by a dense sheath of matrix material. Dye injections revealed that the branchial and pericardial form open systems whereas in piston and annular cartilages a closed system exists. These variations in architecture are reflected in their different mechanical properties and in vivo functions.
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Monteiro, Priscilla de Souza. "O efeito do hipotiroidismo experimental sobre os componentes da matriz extracelular de aortas torácicas de ratos." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/42/42131/tde-29012013-081814/.
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O objetivo deste estudo foi investigar os efeitos do hipotiroidismo experimental sobre o leito vascular da aorta torácica. Para a análise histológica foram realizadas colorações de hematoxilina-eosina, picrosirius e Weigert. Na análise de expressão proteica, foram realizadas as quantificações para colágeno I e III, elastina, MMP-9 e MMP-2, TIMP-1 e TIMP-2. As análises histológicas demonstraram uma diminuição da AST das aortas dos animais hipo e juntamente a esta alteração, foi constatada a diminuição da expressão proteica de colágeno do tipo I. Em relação à elastina, foi possível observar aumento da expressão deste elemento nas aortas dos animais hipotiroideos. Na avaliação da expressão proteica para MMP-9, foi possível verificar uma redução desta proteína no grupo hipotiroideo, assim como um aumento da expressão de TIMP-2. Frente aos presentes resultados, é possível sugerir que o estado hipometabólico desencadeado pelo hipotiroidismo afeta as CMLVs comprometendo mecanismos de síntese/degradação, alterando o importante arranjo da MEC presente na aorta torácica.The aim of this study was to investigate hypothyroidism effects on thoracic aorta wall. For histological analyses were performed stains like hematoxilin-eosin, picrosirius and Weigert. In the protein expression assays were performed quantification for collagen I and III, elastin, MMP-9, MMP-2, TIMP-1 and TIMP-2. The histological analyses showed a decrease in aortas CSA and also a decrease in protein expression of collagen I in the hypo group. As regards to elastin, was possible to see an increase of this protein expression in hypo animals. In the evaluation for MMP-9 expression, was found a decrease in this protein and for TIMP-2 an increase in hypothyroidism group. Facing to these results, is possible to suggest that the hypometabolic state triggered by hypothyroidism, affects the VSMCs compromising mechanisms of synthesis/degradation and changing the important constitution of thoracic aorta ECM.
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Wang, Ziyu. "Development of electrospun tropoelastin-polyglycerol sebacate scaffolds for soft tissue engineering applications." Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/27880.
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Soft tissue damages from disease, trauma, and ageing often have limited regeneration capability, leading to the loss of tissue functions and impacting the quality of life. Repair tissue damage using polymeric materials can alleviate issues such as donor shortage and transplantation rejection associated with undesirable immune responses. This project developed tropoelastin-polyglycerol sebacate (tropelastin-PGS) scaffolds with a spectrum of 3D microstructures, tuneable mechanical properties, controllable degradation profile, and excellent biocompatibility suitable for diverse soft tissue applications. Specifically, we tested their ability to repair vascular and skin tissue through in vitro experiments and animal models.
For vascular repair, tropoelastin-PGS vascular graft was shown to support vascular endothelial cell and smooth muscle cell proliferation and allowed them to express vascular-related functions in vitro. Implanted tropoelastin-PGS vascular graft stayed patent for eight months before sacrifice and harvesting. Histology and immunohistochemistry analysis showed that tropoelastin-PGS graft was completely remodelled into a neoartery with de novo generated extracellular matrix including collagen and organised elastic fibres that mimics the elastic lamellae in the native artery.
For skin repair, the tropoelastin-PGS scaffold accelerated wound healing by modulating the local and systemic immune responses. Locally, tropoelastin-PGS treated wound showed reduced inflammation and recruited more M2 macrophage compared to a commercial product Integra® and PGS control, contributing to enhanced wound healing. Systemically, the addition of tropoelastin reduced the relative spleen size. Through flow cytometry, the spleen of the tropoelastin-PGS group contained fewer granulocytes and monocytes compared to PGS and was shown to have an early and stronger engagement with the lymphoid cells associated with the adaptive immune response.
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Isenburg, Jason C. "Stabilization of vascular elastin by treatment with tannins." Connect to this title online, 2006. http://etd.lib.clemson.edu/documents/1171041760/.
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Kothapalli, Chandrasekhar R. "Cues for cellular assembly of vascular elastin networks." Connect to this title online, 2008. http://etd.lib.clemson.edu/documents/1219849109/.
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Wilcox, Donna. "The role of cathepsin L in elastin degradation." Thesis, Open University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.277118.
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Zhou, Mingjun. "Elastin-Like Peptide Dendrimers: Design, Synthesis, and Applications." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/101661.
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Elastin like peptides (ELPs)—derived from the protein elastin—are widely used as thermoresponsive components in biomaterials due to their LCST (lower critical solution temperature) behavior at a characteristic transition temperature (Tt). While linear ELPs have been well investigated, few reports focused on branched ELPs. Using lysine (Lys, with an additional side-chain amine) as branching units, ELP dendrimers were synthesized by solid-phase peptide synthesis (SPPS) with up to 155 amino acid residues. A secondary structure change with decreasing ratio of random coil and increasing ratio of β-turn upon heating, which is typical of linear ELPs, was confirmed by circular dichroism spectroscopy for all peptides. Conformational change did not show evident dependence on topology, while a higher Tt was observed for dendritic peptides than for their linear control peptides with the same number of GLPGL repeats. Variable-temperature small-angle X-ray scattering (SAXS) measurements showed a size increase and fractal dimension upon heating, even below the Tt. These results were further confirmed by cryogenic transmission electron microscopy (cryo-TEM), and micro differential scanning calorimetry (micro-DSC), revealing the presence of aggregates below the Tt. These results indicated the presence of a pre-coacervation step in the LCST phase transition of the ELP dendrimers.
We further prepared hydrogels by crosslinking hyaluronic acid (HA) with ELP dendrimers. We invesigated their physical properties with scanning electron microscopy (SEM), swelling tests, SAXS, and model drug loading/release experiments. Most of the HA_denELP hydrogels retained transparent upon gelation, but after lyophilization and reswelling remained opaque for days. This reswelling process was carefully investigated with time-course SAXS studies, and was attributed to forming pre-coacervates in the gelation step, which slowly reswelled during rehydration. We then prepared hydrogels with H2S-releasing aroylthiooxime (SATO) groups and showed human neutrophil elastase-responsive H2S-releasing properties with potential applications in treating chronic diseases with recurring inflammation.
Furthermore, we prepared a series of wedge-shaped triblock polyethylene glycol (PEG)-ELP dendrimer-C16 (palmitic acid) conjugate amphiphiles with adjustable Tts. Various techniques were used to investigate their hierarchical structures. The triblock PEG-peptide-C16 conjugate amphiphiles were thermoresponsive and showed a morphology change from small micelles to large aggregates. However, the hydrophilic shell and strong tendency for micelle formation limited the thermoresponsive assembly, leading to slow turbidity change in the LCST transition. The secondary structure was twisted from conventional β-sheet, and the thermoresponsive trend observed in typical ELP systems was not observed, either. Variable temperature NMR showed evidence for coherent dehydration of the PEG and ELP segments, probably due to the relatively short blocks. Utilizing the micelles with hydrophobic cavity, we were able to encapsulate hydrophobic drugs, with promising applications for localized drug release in hyperthermia.Doctor of Philosophy
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Monfort, Dagmara Anne. "Recombinant Elastin Based Nanoparticles for Targeted Gene Therapy." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6627.
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Gene therapy is a technique used to inactivate, replace or insert a corrective copy of a defective gene in order to help diseased tissues to function properly. Gene therapy is a promising treatment for many diseases cancer, cystic fibrosis, and Parkinson’s. There are different methods to introduce a gene to the cell; one of them is the use of viruses. Among viruses, lentiviruses have been popular vectors for gene delivery due to their efficient mode of gene delivery. However, the non-specific delivery of genes associated with viruses may result in undesirable side effects. Here, we propose a heterogeneous nanoparticle delivery system for targeted delivery of lentiviral particles containing a therapeutic gene. The heterogeneous nanoparticles (NPs) consist of the low density lipoprotein receptor 3 (LDLR3) and the keratinocyte growth factor (KGF), each fused to elastin-like-polypeptides (ELPs), LDLR3-ELP and KGF-ELP, respectively. Our results show that while homogeneous nanoparticles comprising of LDLR3-ELP alone blocked viral transduction, heterogeneous nanoparticles comprising of KGF-ELP and LDLR3-ELP enhanced viral transduction in cells expressing high levels of the KGF receptors (KGFR) compared to cells expressing low levels of KGF receptors. Overall, this novel design may help with the targeting of specific cells that overexpressed growth factor such as KGFR.
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Wu, Wendy J. "Structure and properties of recombinant human tropoelastin, domain 26A and mutant forms." Thesis, The University of Sydney, 2000. https://hdl.handle.net/2123/27598.
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This thesis outlines a series of investigations of the structure and properties of full-length tropoelastin, intermolecular interactions of tropoelastin and the effects of an inherited disorder on the association properties of human tropoelastin.
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Grant, Tyler M. "Microstructural deformation of tendon." Thesis, University of Oxford, 2014. http://ora.ox.ac.uk/objects/uuid:0ad70415-af7a-4b97-a93a-d17a73d8ff44.
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Tendon disorders are painful, disabling, and a major healthcare problem, with millions of people affected by tendon injuries each year. Current treatment strategies are inadequate and knowledge of the underlying mechanobiological mechanisms is required to develop novel therapies. Although the tissue–level properties of tendon are well–documented there remains a lack of understanding of the deformation mechanisms of this complex tissue. Therefore, the aim of this thesis is to characterize the microstructural deformation of tendon through biological imaging, mechanical testing, and computational modeling. Emphasis is placed on the structure and function of elastic fibers in tendon, whose role is poorly understood. First, histology, immunohistochemistry, and multiphoton microscopy are used to characterize the organization of elastic fibers in healthy and damaged tendon providing detailed microstructural information on their morphology and location for the first time. Elastic fibers are found to have a sparse distribution in the extracellular matrix, but are highly concentrated in the endotenon sheath and pericellular matrix. Moreover, damaged specimens are found to have a severely disrupted elastic fiber network. Elastic fibers likely contribute to fascicular deformation mechanisms and the micromechanical environment of tenocytes, which are expected to be disrupted in damaged tendon. Second, mechanical testing and enzyme treatments are used to analyze the mechanical contribution of elastic fibers to tendon. Elastase is found to significantly affect the mechanical properties of the tissue and remove the elastin component of both tendon and a control collagen–elastin biomaterial. However, elastase is also found to degrade non–elastin structural molecules that may contribute to tendon mechanics. The mechanical changes associated with the elastase treatment suggest that elastic fibers do not contribute to the elastic recoil of tendon as previously hypothesized. Third, multiphoton microscopy in combination with a novel microtensile testing machine is used to observe the deformation of collagen fibrils and tenocytes in tissue exposed to load. Tissue displacement is consistent with a helical arrangement of fibrils and nuclei experience significant elongation under physiological conditions. These results suggest that a helical arrangement of fibrils is responsible for the nonlinear stress–strain response of tendon and that nuclei are prime candidates for sensing mechanical forces in tendon. Finally, computation modeling and structural imaging are used to generate a microstructural finite element model of tendon. A helical model with embedded pericellular matrix is able to reproduce the stress–strain response and cell–level deformation of the tissue. The pericellular matrix is found to amplify mechanical forces exposed to cells, which is required to initiate mechanobiological stimulation of tenocytes under physiological conditions. Therefore, the structure and composition of the PCM during health and disease is expected to significantly affect mechanobiological mechanisms of tendon. The work presented in this thesis has used new experimental methods to provide novel insight into the structure, function, and deformation mechanisms of tendon. The techniques and concepts developed are widely applicable to the study of collagenous tissues in health and disease. In particular, observations regarding the pericellular matrix may lead to the development of new tissue–engineered and pharmacological strategies for the treatment of tendon disorders.
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Patel, Dhaval Pradipkumar. "Novel PEG-elastin copolymer for tissue engineered vascular grafts." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45811.
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The growing incidences of coronary artery bypass graft surgeries have triggered a need to engineer a viable small diameter blood vessel substitute. An ideal tissue engineered vascular graft should mimic the microenvironment of a native blood vessel, while providing the adequate compliance post-implantation. Current vascular graft technologies lack the ability to promote vascular ECM deposition, leading to a compliance mismatch and ultimately, graft failure. Hence, in order to engineer suitable vascular grafts, this thesis describes the synthesis and characterization of novel elastin mimetic peptides, EM-19 and EM-23, capable of promoting vascular ECM deposition within a poly(ethylene glycol) diacrylate (PEG-DA) hydrogel. By combining the material properties of a synthetic and bio-inspired polymer, a suitable microenvironment for cell growth and ECM deposition can be engineered, leading to improved compliance.
As such, characterization of EM-19 and EM-23 was conducted in human vascular smooth muscle cell (SMC) cultures, and the peptides self-assembled with a growing elastic matrix. After grafting the peptides onto the surface of PEG-DA hydrogels, EM-23 increased SMC adhesion by 6000% over PEG-RGDS hydrogels, which have been the gold standard of cell adhesive PEG scaffolds. Moreover, EM-23 grafted surfaces were able to promote elastin deposition that was comparable to tissue cultured polystyrene (TCPS) surface even though TCPS had roughly 4.5 times more SMCs adhered. Once translated to a 3D model, EM-23 also stimulated increased elastin deposition and improved the mechanical strength of the scaffold over time. Moreover, degradation studies suggested that EM-23 may serve as a template that not only promotes ECM deposition, but also allows ECM remodeling over time. The characterization studies in this thesis suggest that this peptide is an extremely promising candidate for improving vascular ECM deposition within a synthetic substrate, and that it may be beneficial to incorporate EM-23 within polymeric scaffolds to engineer compliant vascular grafts.
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Kambow, Sumit H. "Characterization of Elastin-like Polypeptide Micelles Using Capillary Viscometry." Cleveland State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=csu1337605892.
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Lindsay, Amanda. "Behaviour of alpha-elastin in bulk and at aqueous surfaces." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/3222.
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Tampelini, Flávio Silva. "Efeito do exercício fisico aeróbio sobre os componentes fibroelástico e colágeno da aorta de ratos normotensos e hipertensos, sedentários e treinados." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/42/42131/tde-30052008-120037/.
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O objetivo deste trabalho foi avaliar o efeito do exercício físico aeróbio sobre alterações morfológicas ocorridas na parede da aorta abdominal de animais hipertensos (SHR) e normotensos (WKY), sedentários (S) e treinados (T). Ratos SHR e WKY foram utilizados, que consistia de quatro grupos divididos em WKYS, WKYT, SHRS, SHRT. O treinamento durou 13 semanas, sendo 5 horas por semana, 1 hora por dia. Os resultados deste estudo mostraram que o exercício físico foi eficaz em reduzir a pressão arterial, a freqüência cardíaca e a razão parede/luz, bem como em aumentar a quantidade de fibras elásticas e a luz do vaso no grupo SHRT, em comparação ao grupo SHRS. Em relação à expressão protéica de colágeno I e III, os SHR apresentaram um significativo aumento em relação ao grupo WKY e o grupo SHRT apresentou significativa redução em relação ao SHRS. A a-actina mostrou maior expressão nos grupos WKYS e SHRS, quando comparado com seus respectivos grupos treinados e a elastina mostrou-se significante aumento na expressão nos grupos treinados em relação aos grupos sedentários.The aim of this study was to evaluate the effect of aerobic exercises on morphological changes on abdominal aorta wall, in hypertensive (SHR) and normotensive (WKY) animals, sedentary (S) and trained (T). SHR and WKY were used on the experimental protocol that consisted in four groups divided in WKYS, WKYT, SHRS and SHRT. Trained groups were submitted to a training protocol that lasted 13 weeks, 5 hours a week, 1 hour a day. Results showed that physical exercises were effective not only in reducing blood pressure, cardiac frequency and wall-to-lumen ratio, but also in increasing the number of elastic fibers and the internal diameter in SHRT, in comparison to SHRS. According to collagen I and III protein expression, in both, SHR presented a bigger expression than WKY group. Moreover, SHRT group showed a significant reduction of protein expression in comparison to SHRS. a-actin showed to be more expressed in WKYS and SHRS, in relation to the WKYT and SHRT groups and elastin showed a significant increased in WKYT and SHRT in relation to the sedentary groups.
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Balderrama, Fanor Alberto. "Incorporation of recombinant fibronectin into genetically engineered elastin-based polymers." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/31640.
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Thesis (M. S.)--Bioengineering, Georgia Institute of Technology, 2010.Committee Chair: Chaikof, Elliot; Committee Member: Conticello, Vincent; Committee Member: Jo, Hanjoong. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Scott, Michael J. "The elastin and collagen microstructure of aortic heart valve cusps." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ32327.pdf.
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Chen, Vivian Wenjun. "Human elastin peptide-coated synthetic materials in blood-contacting applications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0005/MQ45895.pdf.
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Chen, Li Hsuen. "Identification of potential exosite in cathepsin V necessary for elastin degradation." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/4069.
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Besides collagen, elastin is the most common connective tissue structural protein in
vertebrates and similar to collagen relatively resistant to non-specific degradation.
Typical elastolytic proteases are the serine-dependent pancreatic and leukocyte elastases,
the Zn-dependent matrix metalloproteinase 12, and several lysosomal cysteine proteases.
Among the cysteine cathepsins, cathepsins S, K and V are highly potent elastases with
cathepsin V displaying the highest activity among all known mammalian elastases.
Despite a shared amino acid sequence identity of over 80% between cathepsins V and L
and very similar subsite specificities, only cathepsin V has a potent elastase activity
whereas cathepsin L lacks it. A series of chimera mutants containing various proportions
of cathepsin V and cathepsin L were constructed in an attempt to define a specific region
needed for elastin degradation. It was found that retaining the peptide sequence region
from amino acids 89 to 119 of cathepsin V preserves the mutant’s elastolytic activity
against elastin-Rhodamine conjugates whereas the region FTVVAPGK (amino acids
112-119) contributes approximately 60% of activity retention. Several additional mutant
proteins involving mutual swapping of residues VDIPK (amino acids 113-117) of
cathepsin L with residues TVVAPGK (amino acids 113-119) of cathepsin V, deletion of
Glyl 18 from cathepsin V, and insertion of Gly between Prol 16 and Lysi 17 in cathepsin
L were constructed and evaluated for their elastolytic activities. The results obtained with
those mutant cathepsin proteins support the importance of the amino acid region spanning
the residues from 112 to 119 in cathepsin V. Based on the 3-D structure of cathepsin V,
this peptide region is located below subsite binding pocket S2 and forms a wall-like
barrier which may act as an exosite for the productive binding of cross-linked elastin.
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Ravi, Swathi. "Recombinant elastin analogues as cell-adhesive matrices for vascular tissue engineering." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42728.
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Biomimetic materials that recapitulate the complex mechanical and biochemical cues in load-bearing tissues are of significant interest in regenerative medicine and tissue engineering applications. Several investigators have endeavored to not only emulate the mechanical properties of the vasculature, but to also mimic the biologic responsiveness of the blood vessel in creating vascular substitutes. Previous studies in our lab generated the elastin-like protein polymer LysB10, which was designed with the capability of physical and chemical crosslinks, and was shown to display a range of elastomeric properties that more closely matched those of the native artery. While extensive validation of the mechanical properties of elastin-mimetic polymers has demonstrated their functionality in a number of tissue engineering applications, limited cell growth on the surfaces of the polymers has motivated further optimization for biological interaction. Recent biologically-inspired surface strategies have focused on functionalizing material surfaces with extracellular matrix molecules and bioactive motifs in order to encourage integrin-mediated cellular responses that trigger precise intracellular signaling processes, while limiting nonspecific biomaterial interactions. Consequently, this dissertation addresses three approaches to modulating cellular behavior on elastin-mimetic analogs with the goal of promoting vascular wall healing and tissue regeneration: genetic engineering of elastin-like protein polymers (ELPs) with cell-binding domains, biofunctionalization of elastin-like protein polymers via chemoselective ligation of bioactive ligands, and incorporation of matrix protein fibronectin for engineering of cell-seeded multilamellar collagen-reinforced elastin-like constructs.
The synthesis of recombinant elastin-like protein polymers that integrate biologic functions of the extracellular matrix provides a novel design strategy for generating clinically durable vascular substitutes. Ultimately, the synthesis of model protein networks provides new insights into the relationship between molecular architecture, biomimetic ligand presentation, and associated cellular responses at the cell-material interface. Understanding how each of these design parameters affects cell response will contribute significantly to the rational engineering of bioactive materials. Potential applications for polymer blends with enhanced mechanical and biological properties include surface coatings on vascular grafts and stents, as well as composite materials for tissue engineered scaffolds and vascular substitutes.
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Leonard, Alex. "Elastin Like Polypeptides as Drug Delivery Vehicles in Regenerative Medicine Applications." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/5981.
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Elastin like polypeptides (ELPs) are a class of naturally derived biomaterials that are non-immunogenic, genetically encodable, and biocompatible making them ideal for a variety of biomedical applications, ranging from drug delivery to tissue engineering. Also, ELPs undergo temperature-mediated inverse phase transitioning, which allows them to be purified in a relatively simple manner from bacterial expression hosts. Being able to genetically encode ELPs allows for the incorporation of bioactive peptides and functionalization of ELPs. This work utilizes ELPs for regenerative medicine and drug delivery.
The goal of the first study was to synthesize a biologically active epidermal growth factor-ELP (EGF-ELP) fusion protein that could aid in the treatment of chronic wounds. EGF plays a crucial role in wound healing by inducing epithelial cell proliferation and migration, and fibroblast proliferation. The use of exogenous EGF has seen success in the treatment of acute wounds, but has seen relatively minimal success in chronic wounds because the method of delivery does not protect exogenous EGF from degradation, or prevent it from diffusing away from the application site.
We created an EGF-ELP fusion protein to combat these issues. As demonstrated through the proliferation of human skin fibroblasts in vitro, the EGF-ELP may be able to aid in the treatment of chronic wounds. Furthermore, the ability of the EGF-ELP to self-assemble near physiological temperatures could allow for the formation of drug depots at the wound site and minimize diffusion, increasing the bioavailability of EGF and enhancing tissue regeneration.
The objective of the second study was to create an injectable hydrogel platform that does not require conjugation of functional moieties for crosslinking or biological activity. Hydrogels are three-dimensional polymer networks that are able to absorb water and biological fluids without dissolving. Their high water content gives them physical properties similar to soft tissues, making them useful as scaffolds for cell migration and drug delivery vehicles. Injectable hydrogels that crosslink in situ are particularly useful because they can form to the shape of the defect, providing a near perfect fit. However, many hydrogel platforms cannot be crosslinked in situ because cytotoxic crosslinking reagents are required. Additionally, hydrogels typically require the chemical conjugation of crosslinking domains and bioactive peptides to the polymer backbone, adding more steps and time required for hydrogel production.
We devised an injectable hydrogel platform that can be synthesized in a single step using photoreactive ELPs as the polymer backbone. Leucine auxotrophic Eshcherichia coli expressed ELPs containing photoleucine, a leucine analog and photoreactive diazirine crosslinker, which is substituted for leucine periodically throughout the ELP sequence. Upon exposure to ultraviolet radiation (~370 nm), photoleucine is able to form covalent crosslinks with amino acid side chains, forming a polymer network for hydrogel formation. Additionally, recombinant growth factors and morphogens can be encoded into the ELP sequence providing a simple method of hydrogel functionalization for regenerative medicine applications.
The potential for this platform was demonstrated through in vivo crosslinking of photoreactive ELPs in the expression hosts. Though the production of the photoreactive ELP was not as forthright as originally assumed. The substitution of noncanonical amino acids typically requires the auxotrophic expression hosts to be starved of the amino acid that they are auxotrophic for. A noncanonical analog of said amino acid can then be supplemented into expression media, maximizing incorporation. In this investigation, it was found the addition of photoleucine alone inhibited photoreactive ELP expression. ELP expression only occurred in the presence of photoleucine if valine or leucine was also present in the media. Furthermore, valine was found to aid the production of ELPs as much as leucine. It was postulated the bacterial translational machinery might need to be altered for optimal ELP expression.
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Hillery, Claire. "The role of elastin in the mechanical properties of conduit arteries." Thesis, Queen Mary, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417835.
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Neocleous, Vassos K. "UVR effects on collagen and elastin gene products in mouse skin." Thesis, London Metropolitan University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287619.
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Xiao, Ye. "Synthesis and self-assembly of polysaccharide-b-elastin-like polypeptide bioconjugates." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0172.
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L’association de polysaccharides naturels et de polypeptides recombinants de type élastine (ELP) dans des structures de copolymères à blocs doit permettre d’accéder à des matériaux possédant des propriétés d’auto-assemblage sous l’action de stimuli et potentiellement bioactifs. Nous avons réalisé et présentons ici la synthèse d'une série de bioconjugués polysaccharide-b-ELP, dans lesquels 4 polysaccharides hydrophiles différents ont été couplés à l'extrémité N-terminale de l’ELP par "chimie click".Ces bioconjugués ont été caractérisés par RMN 1D et 2D, SEC et FTIR. Leur thermo-sensibilité et leur auto-assemblage induit par la température ont été étudiés par spectroscopie UV-Visible, DLS, SLS, SANS et AFM liquide à température contrôlée. Cette étude a démontré que les bioconjugués polysaccharide-b-ELP peuvent s'auto-assembler en milieu aqueux en nanoparticules bien définies au-dessus d'une température de transition spécifique et modulable (Tt) et se désassembler de façon réversible sous la Tt, ce qui les rend particulièrement prometteurs pour la conception de vecteurs de principes actifs à libération contrôlée. La fonctionnalisation chimiosélective des résidus méthionine du segment ELP par chimie de l'oxaziridine a également été exploitée pour moduler les propriétés des bioconjuguésThe combination of natural polysaccharides and recombinant elastin-like polypeptides (ELPs) into block copolymers is expected to lead to materials with precise stimuli-responsive self-assembly properties and bioactivities. Herein, we report the synthesis of a series of polysaccharide-b-ELP bioconjugates, in which 4 different hydrophilic polysaccharides were coupled to the N-terminal end of an ELP via “click chemistry”. The resulting bioconjugates were characterized by 1D and 2D NMR, SEC and FTIR. Their thermal sensitivity and temperature-triggered self-assembly in aqueous solution were investigated by UV-Vis spectrometry, DLS, SLS, SANS and temperature-controlled liquid AFM. This study demonstrated that polysaccharide-b-ELP bioconjugates can self-assemble into well-defined nanoparticles in aqueous condition above a specific and tunable transition temperature (Tt) and reversibly disassemble below the Tt, which make them particularly promising candidates for the design of controlled drug delivery nanocarriers. Chemoselective functionalizations of the ELP segment at methionine residues using oxaziridine chemistry were additionally applied for further tuning of bioconjugates’ properties
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Ghoorchian, Ali. "Modification of Behavior of Elastin-like Polypeptides by Changing Molecular Architecture." Cleveland State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=csu1336745204.
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Petitdemange, Rosine. "Chemoselective modifications of recombinant elastin-like polypeptides : tuning thermosensitivity and bioactivity." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0360/document.
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La thèse présentée porte sur la préparation de dérivés de polypeptides recombinant à base de motifs élastine (ELPs) ainsi que sur l'étude de leurs propriétés physicochimiques et biologiques. Des ELPs contenant des résidus méthionine ont été modifiés de manière chimiosélective soit en utilisant des halogénures d'alkyle ou différents époxydes, soit par oxydation des résidus méthionine. La caractérisation par RMN et par spectrométrie de masse des composés obtenus a permis de confirmer leur fonctionnalisation quantitative. L'étude de la réponse en température de ces dérivés d'ELP par des mesures de turbidité ou par des mesures de diffusion de la lumière a montré le fort impact des modifications entreprises sur la température de transition (TI) des ELPs. Il a également été montré que la n peut être modifiée par échange des contre-ions des dérivés cationiques. Enfin, des monosaccharides ont été conjugué aux ELPs contenant des groupements alcyne par cycloaddition de Huisg en afin d'obtenir des glycopolypeptides. Les propriétés thermosensibles ainsi que les propriétés biologiques de ces conjugués ont été testées et ces dernières ont permis de montrer leur capacité à se lier sélectivement à des lectines. Leur utilisation pour trier des protéines d'intérêt et les redisperser est finalement évaluée de façon préliminaireThis thesis describes the preparation of elastin-like polypeptides (ELPs) derivatives and the study of their physico-chemical and biological properties. Methionine-containing ELPs were chemoselectively modified using either alkyl halides or epoxides or by oxidation of their methionine residues. The successful functionalization was assessed by NMR and mass spectrometry analysis of the resulting compounds. The thermoresponsive properties of these ELP derivatives were evaluated either by light scattering or by turbidity measurements showing the strong effect of these modifications on the ELPs transition temperature (TI). The counterion affect on the thermosensitivity of the polycationic derivatives was also studied. The synthesis of ELP glycopolypeptides was finally achieved by conjugating monosaccharides to the ELP alkyne derivatives through Huisgens cycloaddition. Along with the thermoresponsive properties, the bioactivity of the ELP glycoconjugates was studied and proved their ability to specifically bind lectins. Their use for protein sorting and release was preliminary evidenced
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Kawabata, Shingo. "The development of a novel wound healing material, silk-elastin sponge." Kyoto University, 2019. http://hdl.handle.net/2433/243272.
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Sbruzzi, Ivanete Chaves. "Estudo de marcadores polimórficos da região 7q11.23 para o diagnóstico da síndrome de Williams-Beuren." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/5/5141/tde-29012007-133658/.
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INTRODUÇÃO: A síndrome de Williams-Beuren (SWB) resulta de uma deleção de aproximadamente 1.5 Mb na região 7q11.23. A haploinsuficiência ocasiona alterações do desenvolvimento neurológico assim como malformações em múltiplos sistemas. OBJETIVOS: Testar utilidade de marcadores polimórficos para o diagnóstico da síndrome, determinar a proporção de pacientes com microdeleção, comparar características clínicas entre pacientes com e sem microdeleção e investigar origem parental. MÉTODOS: Selecionamos 32 pacientes com avaliação clínica para SWB atendidas no ICr. Critérios de inclusão: presença de dismorfismo craniofacial acompanhado ou não de alterações cardiovasculares, comportamento característico ou hiperacusia. Para a genotipagem do trio - afetado, mãe e pai, utilizamos os marcadores D7S1870, Eln 17/éxon18 e Hei. Análise em gel de poliacrilamida à 7% com imagens digitalizadas. RESULTADOS: Os marcadores D7S1870, Hei e Eln17/éxon18 foram 78% informativos e 22% não informativos. O marcador mais informativo foi o D7S1870 69%, seguido do Hei 55% e ELN 17/éxon18 em 43%. Houve microdeleção em 56% e ausência em 22%. A origem parental da deleção foi 9 materna e 8 paterna. As alterações craniofaciais e cardiovasculares não tiveram diferenças estatisticamente significantes entre portadores e não portadores da microdeleção. O comportamento amigável resultou numa diferença estatística muito significante (p=0,006) onde 88% tinham e 28% não tinham microdeleção. A hiperacusia teve diferença estatística significante (p=0,020) presente em 55% dos pacientes com microdeleção. CONCLUSÃO: Os dados obtidos demonstraram que os marcadores utilizados são úteis no diagnóstico da SWB e acessível para utilização em serviço público.INTRODUCTION: Williams-Beuren syndrome (WBS) results of ~1.5 Mb commonly deleted region chromosome 7q11.23 in 90-95% of all clinically typical cases. The clinical manifestations can be variable and is a developmental disorder with multisystem manifestations caused by haploinsufficiency for contiguous genes in this region. OBJECTIVE: Polimorphic markers were tested to determine the proportion of patients with and without microdeletion, to compare the clinical features and to establish the parental origin of the deletion. METHODS: 32 probands with WBS ascertained according to well-established diagnostic criteria. Genotyping using polimorphic markers D7S1870, Eln 17/éxon18 and Hei was performed on DNA from the patients and their available parents. RESULTS: The three markers were informative in 78% and non informative in 22%. The best marker was D7S1870 with 69%, followed by Hei in 55% and ELN 17/éxon18 in 43%.The microdeletion was present in 56% and absent in 22%. Craniofacial and cardiovascular alterations did not have significant statistical differences between probands with or without microdeletion. Two following characteristics (friendly personality and hyperacusia) were more frequent in the deleted group and these differences were statistical significant (p=0,006 and 0,02 respectively). CONCLUSIONS: Polimorphic markers used here demonstrated its viability and utility for the confirmation diagnosis of SWB in a public service.
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Krex, Dietmar, Inke R. König, Andreas Ziegler, Hans K. Schackert, and Gabriele Schackert. "Extended Single Nucleotide Polymorphism and Haplotype Analysis of the elastin Gene in Caucasians with Intracranial Aneurysms Provides Evidence for Racially/Ethnically Based Differences." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-135316.
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Background: There is growing evidence that genetic variants have an impact on the pathogenesis of intracranial aneurysm (IA). Recently, the genetic locus around the elastin gene (7q11) has been identified as linked to IA in a Japanese population. Our aim was to confirm these results in Caucasian populations. Methods: We conducted a case-control study in 120 Caucasian patients with IA and 172 controls to investigate 8 single nucleotide polymorphisms (SNPs) and various haplotypes within the elastin gene, which were frequently found and associated with the phenotype in the Japanese populations. Real-time PCR and melting curve analysis were used for the detection of genotypes. Results: Allele frequencies and genotypes were equally distributed between Caucasian cases and controls. We failed to identify haplotypes that are associated with the phenotype in our population, which is in contrast to the Japanese study. However, allele frequencies in control populations differ between Caucasians and Japanese. Conclusions: We found no association between SNPs and haplotypes of the elastin gene and the occurrence of IA in our Caucasian populations. However, our data provide strong evidence for racial/ethnic differences in the association of SNP and specific haplotypes of the elastin gene with the phenotype. There might be other genetic variants of the elastin gene associated with IA in CaucasiansDieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich
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Winfield, Kaye R. "Extraction of desmosines from urine : an indicator for inflammatory lung damage /." Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0059.
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Vrhovski, Bernadette. "Recombinant human tropoelastin : production, properties and interactions." Thesis, The University of Sydney, 1997. https://hdl.handle.net/2123/27631.
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Moraes, Renato de. "Utilização da membrana de elastina associada a hidroxiapatita e proteína morfogenética óssea no reparo de defeitos cranianos de ratos." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/82/82131/tde-20082018-134054/.
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Devido as limitações relacionadas ao emprego do enxerto autólogo, o uso dos biomateriais poliméricos naturais tornou-se uma opção viável em terapias regenerativas do tecido ósseo. O objetivo desse trabalho é avaliar de forma qualitativa e quantitiva a contribuição da membrana de elastina utilizada isoladamente ou em associação a hidroxiapatita e proteína morfogenética óssea, no reparo de defeitos ósseos no crânio de ratos. Foram utilizados 49 ratos (Rattus norvegicus, Wistar), machos, com peso aproximado de 330 gramas e 4 meses de idade. Os animais foram submetidos ao procedimento cirúrgico para a criação do defeito ósseo no osso parietal esquerdo e divididos em 7 grupos com 7 animais cada. Os grupos foram implantados com os seguintes bioamateriais: grupo 1 controle (G1-C) sem implante, grupo 2 (G2-E24h) membrana de elastina 24 h, grupo 3 (G3-E24h/HA) membrana de elastina 24 h com hidroxiapatita, grupo 4 (G4-E24h/BMP) membrana de elastina 24 h com proteína morfogenética óssea, grupo 5 (G5-E96h) membrana de elastina 96 h, grupo 6 (G6-E96h/HA) membrana de elastina 96 h com hidroxiapatita, grupo 7 (G7-E96h/BMP) membrana de elastina 96 h com proteína morfogenética óssea. Após a morte indolor induzida em 6 semanas, as calotas cranianas foram retiradas para análise macroscópica, radiográfica, histológica e morfométrica. As análises macroscópicas, radiográficas e histológicas demonstraram a biocompatibilidade dos biomateriais utilizados. As médias e desvios-padrão do volume percentual relativo de osso neoformado nos defeitos cranianos dos grupos G1 a G7 foram 7,87±2,53; 24,01±0,55; 9,59±1,27; 31,31±6,37; 19,77±2,62; 7,31±2,43; 43,25±3,72, respectivamente. Os biomateriais mostraram-se biocompatíveis e o grupo 7 (G7-E96h/BMP) resultou na maior neoformação óssea.Due to the limitations related to the use of autologous grafts, the use of natural polymeric biomaterials has become a viable option in regenerative therapies of bone tissue. The objective of this dissertation is to evaluate in qualitative and quantitative way the contribution of the elastin matrice used alone or in combination with hydroxyapatite and bone morphogenetic protein in the repair of bone defects in the skull of rats. Were use 49 Mices (Rattus norvegicus, Wistar), weighting approximately 330 grams and 4 months of age, were used. The animals were submitted to the surgical procedure to create the bone defect in the left parietal bone and divided into 7 groups with 7 animals each. The groups were implanted with the following biomaterials: group 1 control (G1-C) without biomaterial, group 2 (G2-E24h) 24 h elastin membrane, group 3 (G3-E24h/HA) 24 h elastin membrane with hydroxyapatite, Group 4 (G4-E24h/BMP) elastin membrane 24 h with bone morphogenetic protein, group 5 (G5-E96h) elastin membrane 96 h, group 6 (G6- E96h/HA) elastin membrane 96 h with hydroxyapatite, group 7 (G7-E96h/BMP) 96 h elastin membrane with bone morphogenetic protein. After painless death induced at 6 weeks, the skull caps were removed for macroscopic, radiographic, histological and morphometric analysis. Macroscopic, radiographic and histological analysis demonstrated the biocompatibility of the biomaterials used. The mean and standard deviations of the relative percentage volume of newly formed bone in the cranial defects of the G1 to G7 groups were 7,87±2,53; 24,01±0,55; 9,59±1,27; 31,31±6,37; 19,77±2,62; 7,31±2,43; 43,25±3,72, respectively. The implanted biomaterials were shown to be biocompatible and the group 7 (G7-E96h/BMP) resulted with greater bone neoformation.
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Dahal, Shataakshi. "Stem Cells Based Elastic Matrix Regeneration for Small Abdominal Aortic Aneurysms (AAAs) Repair." Cleveland State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=csu1599137475237285.
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Dahal, Shataakshi. "Stem Cells Based Elastic Matrix Regeneration for Small Abdominal Aortic Aneurysms (AAAs) Repair." Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1599137475237285.
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Martinez, Adam W. "Design and development of an elastin mimetic stent with therapeutic delivery potential." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/45926.
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Stenting remains a common treatment option for atherosclerotic arteries. The main drawback of early stent platforms was restenosis, which has been combated by drug eluting stents; however, these stents have suffered from a higher incidence of late stage thrombosis. To address current stenting limitations, the major research focuses have been the development of the next generation of drug eluting stents and first generation bioabsorbable stents. The main objective of this dissertation was the design and development of a new class of bioabsorbable stent composed of elastin mimetic protein polymers. The first phase explored different stent design schemes and fabrication strategies. Successfully fabricated stents were then mechanically tested to ensure they possessed sufficient mechanical strength. Additionally, described herein is the potential to modulate the properties of the elastin mimetics through different crosslinking strategies. We have demonstrated that chemical crosslinking allows for the tailoring of the physical, mechanical, drug delivery, and endothelialization properties of these materials. The potential for drug delivery from this elastin mimetic stent was benchmarked as was the potential to endothelialize these stents. Furthermore, we developed the necessary delivery systems to allow for deployment in the rat aorta model.
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Tang, Mingjie. "SYNTHESIS AND CHARACTERIZATION OF pH-RESPONSIVE ELASTIN-LIKE POLYPEPTIDES WITH DIFFERENT CONFIGURATIONS." Cleveland State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=csu1376784321.
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Helm, Eric. "Solute Partitioning in Elastin-like Polypeptides: A Foundation for Drug Delivery Applications." Cleveland State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=csu1450790146.
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WAN, JIA HONG. "Investigation into the phase separation behavior of concentrated elastin-like polypeptide solutions." Cleveland State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=csu1471923273.
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Sallach, Rory Elizabeth. "Recombinant elastin-mimetic protein polymers as design elements for an arterial substitute." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/29614.
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Thesis (Ph.D)--Biomedical Engineering, Georgia Institute of Technology, 2008.Committee Chair: Elliot Chaikof; Committee Member: Marc Levenston; Committee Member: Robert Nerem; Committee Member: Vincent Conticello; Committee Member: Yadong Wang. Part of the SMARTech Electronic Thesis and Dissertation Collection.
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Ebert, Regina. "Möglichkeiten der Epithelisierung einer Koriumersatzmembran aus Kollagen-Elastin : Experimente an DA-Ratten /." Aachen : Mainz Verlag, 2002. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=009897917&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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Chow, Ming-Jay. "Mechanics and mechanobiology of arteries: contributions and interactions of collagen and elastin." Thesis, Boston University, 2013. https://hdl.handle.net/2144/10966.
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Thesis (Ph.D.)--Boston UniversityThe dynamic mechanical behavior of arteries is essential to a properly functioning vascular system. Within the arterial extracellular matrix (ECM), the organization of collagen and elastin leads to the bulk of the passive mechanical behavior of the tissue. While remodeling of the ECM occurs naturally in healthy arteries to maintain normal functioning, vascular diseases often create different chemical and mechanical conditions that cause significant changes in structure and adverse effects on the mechanical behavior. The goal of this dissertation is to understand the roles of the ECM components in the mechanical behavior of vascular tissues, and how mechanical and biological interactions change during disease. Our study of in vivo obstruction induced pulmonary artery remodeling suggests clinically relevant relationships between the mechanical integrity and biochemical composition of the tissue. Arteries had earlier collagen engagement and increased tissue stiffness due to higher collagen content. An in-vitro treatment with elastase leads to lamellae fragmentation and a faster rate of degradation when tissues were digested under stretch. We have shown for the first time the transition from J-shaped to S-shaped stress-strain behavior in arteries undergoing elastin degradation. This potential for large stretches with minimal increases in pressure could occur as aortic tissue becomes dilated during the formation of aneurysms. Multiphoton imaging during mechanical loading shows that elastin and collagen in the medial and adventitial layers are recruited differently. In the unloaded state, elastin fibers are pre-stretched and apply compressive forces on collagen fibers contributing to their crimping. Upon loading, medial elastin fibers are immediately recruited while the adventitial collagen fibers engage and become the major load-bearing component when strain reaches 20-25%. In contrast medial collagen is engaged throughout loading. After significant removal of elastin, the second harmonic generation suggests collagen fibers become straightened and aligned leading to earlier recruitment and rapidly stiffened mechanical behavior. This microstructural and mechanical information can be applied to constitutive models for prediction of tissue mechanics where collagen and elastin are the major load bearing components. Our study shows that the interactions between the elastin and collagen structure determine the mechanics of arteries and carry important implications to vascular mechanobiology.