Chronic or degenerative diseases affecting the lumbar spine, commonly referred to as low back pain (LPB), are a major cause of dysfunction, pain, and disability worldwide. According to the Global Burden of Disease (GBD) report of 2019, LPB affects over half a billion people, severely limiting their well-being and lifestyle. Unfortunately, these numbers have been steadily increasing over the last decade, with a rise of more than 15%, mainly due to demographic aging of the population, making it a significant socioeconomic global issue. When conservative treatments such as medications, drugs, and injections fail to alleviate the symptoms, surgical interventions become necessary. Spinal surgeries have become increasingly common and account for 40% of the top ten surgical procedures in the United States alone. As a result, the global market for spinal implants and medical orthopedic devices has been growing at a compound annual growth rate (CAGR) of 5.0% in the United States. Degenerative disc diseases, herniated intervertebral discs, and spondylolisthesis are among the most common problems requiring implant surgery, with lumbar interbody fusion cages or total disc replacements being the most common options. These surgical techniques often utilize a metal endplate or hollow cage as a load-bearing structure to ensure correct load transmission and biomechanical spinal functionality. Currently, endplates for total disc replacement are produced using subtractive manufacturing techniques from bulk biomedical-graded metal alloys like Ti-6Al-4V. The endplates are inserted between two adjacent vertebral bodies, where bone ingrowth and implant fusion are necessary. However, the elastic properties of bulk metals and bone tissue do not match, resulting in stress-shielding phenomena, implant loosening, or implant subsidence. These complications frequently necessitate surgical revision of the implant, which not only impacts the daily activities of the patients but also has a relevant economic impact. Therefore, researchers are exploring alternative design and manufacturing strategies to develop next-generation prosthetic devices that overcome these challenges. Metal additive manufacturing (MAM), particularly Laser-Powder Bed Fusion (L-PBF), has revolutionized the fabrication of specialized components with complex shapes, including architected cellular materials - a novel class of engineered materials with tunable mechanical properties. The biomedical field is a prime example of where lattice application has proved beneficial. MAM provides numerous advantages, including patient-specific customization, a vast design space, and reduced stress shielding. However, issues with structural integrity, lack of AM-specific norms, and the need for fine-tuning process optimizations are still hindering MAM's widespread adoption on the international market. An essential issue that requires resolution is the impact of process-induced flaws on the fatigue behavior of components made of L-PBF lattices. Despite a growing body of scientific literature on the fatigue behavior of lattice unit cells, little attention has been given to the function of fatigue at a millimetric scale, specifically the role of sub-unital lattice elements such as struts and junctions. As fatigue is highly localized, understanding primary fatigue behavior and fracture mechanisms at a strut scale may be critical to addressing the aforementioned problems. Moreover, designing proper prosthetic devices requires fulfilling both biomechanical and biological requirements, leading to a bottleneck in component quality. Proper tuning of osteointegration often requires large porosity and small strut dimensions, approaching the limits of industrial 3D printers. This increases the likelihood of manufacturing lattices with unconnected struts, drosses, parasitic masses, and severe deviations from the nominal as-designed geometries, leading to highly susceptible components under fatigue. To address these challenges, combined approaches with bone tissue engineering may be advantageous. Biopolymers from natural sources, such as silk fibroin and collagen derivatives (i.e., gelatin), are widely used for bone-filler applications due to their exceptional biological properties. These polymers can create highly interconnected biodegradable porous 3D scaffolds suitable for cell differentiation towards an osteogenic phenotype, such as in the form of foams. These foams can be embedded into metal lattice structures, resulting in a hybrid composite device that simultaneously fulfills the load-bearing, fatigue, and osteointegrative requirements that a spinal prosthetic device necessitates. This thesis work covers a range of topics mentioned above. Firstly, an introductory theoretical background is presented in Chapter I, followed by experimental findings which are presented in three different chapters. Chapter II is dedicated to the fatigue behavior of L-PBF Ti-6Al-4V sub-unital lattice elements in the form of miniaturized dog-bone specimens that mimic struts and nodes. This chapter is divided into four sections. The first section investigates the fatigue strength of strut-like specimens based on their building orientations at four different angles with respect to the printing job plate. Morphological features of the miniaturized specimens such as average and minimum cross-section, eccentricity, waviness, and surface texture are correlated with fatigue strength. The role of inner and surface defects, such as lack-of-fusion (LoF) and gas holes, is also considered to explain the main failure mechanisms. The impact of building orientation on the printing quality of the specimens is highlighted, with an increase in surface roughness and defectiveness as the printing angle decreases, resulting in a shorter fatigue life for miniaturized struts. In the second section, the fatigue effect is studied across different fatigue regimes. The role of the mean stress effect is assessed using the Haigh diagram, which reveals an increase in fatigue life moving towards compressive loading regimes. The effect of the printing angle is also investigated, showing different trends according to the different stress ratios, suggesting different fatigue failing mechanisms. The third section introduces strut-junction miniaturized specimens and evaluates their fatigue behavior according to building orientations. Horizontal specimens show an increased fatigue life compared to their thin strut counterparts, and different morphological outcomes are highlighted, including improved surface quality even at lower angles, possibly related to the node acting as an additional supporting structure. The fourth section presents a design-led compensation strategy for sub-unital lattice specimens, aimed at reducing as-designed/as-built deviations. This systematic decrease in geometrical mismatch suggests potential new design strategies for fatigue enhancement. In Chapter III, bone tissue engineering strategies are explored for the design of foam scaffolds as bio-fillers for lattice-based design. The feasibility of the polymer-metal composite is assessed, using an N2O-based gas foaming technique to fabricate silk fibroin and silk fibroin/gelatin porous scaffolds infilled into a cubic L-PBF Ti-6Al-4V lattice structure. The adhesion at the polymer/metal interface is assessed, with simultaneous electrowetting, showing promise for better and more intimate contact on the outermost surface of the lattice struts. A statistical-based analysis of the foam porosity is then carried out, aimed at optimization towards osteointegration improvement. Selected foams are biologically evaluated, revealing good cell adhesion and differentiation towards an osteogenic phenotype. Chapter IV reports on two different strategies for the design of a Ti-6AL-4V L-PBF lattice-based endplate for total disc replacement. The first strategy focuses on homogenized-based topology optimization, designing an octet-truss prosthetic device with a graded structure and a cell size suitable for polymeric infilling. The second strategy aims at optimizing octet-truss lattice components for fatigue, evaluating the optimal building orientation for the specimens. Experimental results reveal an improvement in the fatigue life of three-point bending test specimens, suggesting the potential of the proposed model. In Chapter V, the major takeaways of this thesis work are discussed, highlighting important advancements in understanding the fatigue behavior of lattice structures and the development of novel hybrid strategies for the design of biomedical devices, with a particular focus on spinal orthopedics. Future possible directions for research are also explored.

Tissue engineering (TE) is an interdisciplinary field, in continuous evolution, that possesses as main goal the creation of efficient systems for tissues and organs healing and regeneration. For bone, TE strategies are typically based on the combined use of scaffolds, cells, and bioactive molecules. Different materials were successfully studied and proposed for the fabrication of scaffolds. Among them, silk fibroin (SF) was evaluated as particularly promising for different TE applications, especially for bone tissue regeneration. Silk fibroin, a natural protein forming the structural core of silk filaments, holds biocompatibility, mechanical properties and biodegradation rate suitable for applications in bone regeneration. However, in the past, SF has shown some limitations, especially in terms of bioactivity and effective differentiating ability of hMSCs in regenerating bone tissue. In this work, we wanted to demonstrate that SF, properly processed, chemically modified, and conjugated with selected bioactive species, can be used to prepare different systems: a functionalised scaffold; a bioresorbable material with mineralization ability; an implantable immunomodulatory material. The experimental activities performed and the deep investigation of the properties of the SF-based systems prepared, led to promising results, indicating that SF could be a flexible and powerful platform for the realization of different therapeutic tools. For some of the SF-based systems described in this dissertation, further studies are needed to assess the biological activity of the materials prepared.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Hybrid composites with chitosan (CHI), fibroin (SF) and hydroxyapatite (HA) are biocompatible and attractive for bone engineering applications. The objective of this work was to prepare, to characterize and to evaluate in vitro cells behavior in contact with CHI, CHI/SF and CHI/SF/HA scaffolds. The biomaterials were produced from a CHI, CHI/SF, CHI/SF/HA solution in acetic acid and, after the production process, they were submitted the in vitro tests with STRO+1A, MC3T3-E1 and SaOS-2 cells for 07, 14 and 21 days. The scaffolds were characterized by X-ray diffraction, attenuated total reflection Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscopy and energy dispersive spectroscopy. In addition, tests of porosity, pore size and contact angle were performed. Cell viability and activity were assessed by MTT reduction and alkaline phosphate activity detection. It was possible to prepare scaffolds 3D based on chitosan, fibroin and hydroxyapatite and the interaction between this materials were observed by physicochemical characterization. The composites were considered non-toxic and they were capable to promote cell adhesion, proliferation and differentiation. Additionally, they may be used in the therapy of bone defect repair. / Compósitos híbridos de quitosana (CHI), fibroína (SF) e hidroxiapatita (HA) são biocompatíveis e atrativos para aplicações na engenharia tecidual óssea. O objetivo desse trabalho foi preparar, caracterizar e avaliar o comportamento in vitro de compósitos 3D de CHI, CHI/SF, CHI/SF/HA. Os biomateriais foram produzidos a partir de uma solução de CHI, CHI/SF e CHI/SF/HA em ácido acético e após a realização dos processos de produção foram submetidos a testes in vitro com células STRO+1A, MC3T3-E1 e SaOS-2 por 07, 14 e 21 dias. Os arcabouços foram caracterizados por difração de raios-X, espectroscopia no infravermelho com transformada de Fourier com refletância total atenuada, análise termogravimétrica, calorimetria exploratória diferencial, microscopia eletrônica de varredura, espectroscopia de energia dispersiva, e submetidos a testes para verificação da porosidade, tamanho de poro e ângulo de contato. A viabilidade e a atividade celular foram avaliadas por redução de MTT e pela detecção da atividade de fosfatase alcalina. Foi possível preparar arcabouço 3D com matriz baseada em quitosana, fibroína e hidroxiapatita e houve interação entre esses materiais, sendo constatado através da caracterização físico-química. Ambos os compósitos foram considerados atóxicos e capazes de promover adesão, proliferação e diferenciação celular, podendo ser utilizados na terapia do reparo de defeito ósseo.

Forskningsområdet för bärbar elektronik är fortfarande relativt ungt och det finns ett stort behov av utveckling av nya material inom området. Olika typer av kompositer är mycket intressanta och de ska uppvisa såväl hög hållfasthet som goda ledande egenskaper. I detta avseende är silkes fibroin och MXene mycket intressanta utgångsmaterial eftersom silkestrådarna kan ge en struktur med god jonledningsförmåga och god flexibilitet och MXene kan bidra med hög styvhet och god elektrisk ledningsförmåga. Med detta som bakgrund beslöts att undersöka om kompositer av silkestrådar och MXene kan användas i kompositer som kan användas i bärbar elektronik. 3 olika typer av hydrogeler studerades och de innehöll silkes fibroin med 0, 1 och 5% MXene. De egenskaper som utvärderades var struktur, mekaniska egenskaper, stabilitet i vatten, bionedbrytbarhet och både statisk och dynamisk ledningsförmåga. Resultaten visar att de tillverkade nanokompositerna har lovande förutsättningar inom området eftersom en kombination av silkes fibroin med 5 % MXene har god stabilitet, konduktivitet och en hög och stabil Gauge-faktor. / As the research area of wearable electronics is still relatively new, material science with this focus opens plenty of unexplored fields. That is why a study characterizing the unexplored composite system of silk fibroin and MXene (Silk/MXene) was conducted. These two biocompatible materials are complementary with regard to the requirements for wearable electronics materials. Silk fibroin dispose an ionic conductivity and solid flexibility, while MXene brings mechanical strength and significant increase of electrical conductivity. The reinforced hydrogel materials were studied at two concentrations of fillers, 1% and 5% and compared to pristine silk fibroin. All three materials were studied from the point of view of their structure, mechanical properties, behaviour in aqueous environment, biodegradability and electrical conductivity, both static and dynamic. Nanocomposite systems of silk fibroin and MXene have shown a potential for being used in the intended application area, as Silk/MXene 5% film displays good stability, conductivity with high andstable Gauge factor.

Spider silk displays a unique balance of high tensile strength and extensibility, making it one of the toughest materials on the planet. Dragline silk, also known as the lifeline of the spider, represents one of the best studied fiber types and many labs are attempting to produce synthetic dragline silk fibers for commercial applications. In these studies, we develop a minifibroin for expression studies in bacteria. Using recombinant DNA methodology and protein expression studies, we develop a natural minifibroin that contains the highly conserved N- and C-terminal domains, along with several internal block repeats of MaSp1. We also characterize a family of small cysteine-rich proteins (CRPs) and demonstrate that these factors are present within the spinning dope of the major ampullate gland using MS analysis. Biochemical studies and characterization of one of the family members, CRP1, demonstrate that this factor can self-polymerize into higher molecular weight complexes under oxidizing conditions, but can be converted into a monomeric species under reducing conditions. Self-polymerization of CRP1 is also shown to be independent of pH and salt concentration, two important chemical cues that help fibroin aggregation. Overall, our data demonstrate that the polymerization state of CRP1 is dependent upon redox state, suggesting that the redox environment during fiber extrusion may help regulate the oligomerization of CRP molecules during dragline silk production.

Spiders produce multiple types of silk that exhibit diverse mechanical properties and biological functions. Most molecular studies of spider silk have focused on fibroins from dragline silk and capture silk, two important silk types involved in the survival of the spider. In this study we have focused on the characterization of egg case silk, a third silk fiber produced by the black widow spider, Latrodectus hesperus , whose DNA coding sequences have not been reported. Based upon solubility differences in 8 M guanidine hydrochloride, it is demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and silver staining that the egg case silk is relatively complex at the molecular level, containing a large number of proteins with differing molecular weights. Protein components of egg case silk with a size about 100 kDa were obtained by a solubilization time course study, which indicates these proteins are likely to be embedded in the silk filament. Peptides in these 100 kDa proteins were released by tryptic in-gel and in-solution digestion. The peptides were sequenced using a MALDI tandem TOF mass spectrometer. Some of the de novo sequences were confirmed using a linear ion trap mass spectrometer equipped with a nanospray ion source. Combining the peptide sequences obtained, reverse genetics was employed to trace silk genes encoding proteins containing these de novo peptides. Three silk protein coding sequences were successfully discovered, which encode silk proteins named 3B, T1 and ECSP-1, respectively. 3B and T1 show the standard fibroin protein pattern. Amino acid repeat patterns were observed in these two silk clones. But the amino acid compositions of 3B and T1 show differences with the total amino acid composition of egg case silk, and also, the peptide sequences cannot be found in the primary amino acid sequences of 3B and T1. ECSP-1 protein represents one of the egg case silk proteins with a size of about 100 kDa. A number of peptide sequences obtained by mass spectrometric de novo sequencing were successfully located in ECSP-1's primary amino acid sequence. Sequence analysis demonstrates ECSP-1 represents a new class of silk proteins, with fibroin-like properties. The expression pattern of ecsp-1 is largely restricted to the tubuliform gland inside of the L. hesperus spider, with lower levels detected in the major and minor ampullate glands, which also confirms the identity of ECSP-1. It is also demonstrated that ECSP-1 assembles into higher aggregate structures through the formation of disulfide bonds. Peptide sequences from silk proteins from the Tarantula spider Grammostola rosea were also obtained. These sequences will be beneficial in obtaining genes encoding the silk from this spider species.

Breast cancer is one of the most common types of cancer affecting women in the world today. To better understand breast cancer initiation and progression modeling biological tissue under physiological conditions is essential. Indeed, breast cancer involves complex interactions between mammary epithelial cells and the stroma, both extracellular matrix (ECM) and cells including adipocytes (fat tissue) and fibroblasts (connective tissue). Therefore, the engineering of in vitro three-dimensional (3D) systems of breast tissues allows a deeper understanding of the complex cell-cell and cell-ECM interactions involved during breast tissue development and cancer initiation and progression. Furthermore, such 3D systems may provide a viable alternative to investigate new drug or drug regimen and to model and monitor concurrent cellular processes during tumor growth and invasion. The development of suitable 3D in vitro models relies on the ability to mimic the microenvironment, the structure, and the functions of the breast tissue. Different approaches to develop a novel 3D breast model have been investigated. Most models use gel scaffolds, including Matrigel® and collagen to generate breast tissue-like structures. However, the physicochemical, mechanical, and geometrical properties of these scaffolds only partially meet the mechanical, physical, and chemical parameters of the breast tissue matrix. In the present studies, we investigated the overall hypothesis that electrospun SF-derived scaffolds promote mammary cell growth and the formation of mammary-like structures depending on the composition and/or coating of the scaffolds with ECM proteins. Through an extensive literature search (1) the importance of 3D modeling of tissues and organs in vivo, (2) 3D modeling of the mammary tissue and currently available models, (3) the properties and applications of SF in tissue modeling and regeneration were reviewed (Chapter 1). Our studies provide evidence of the effects of various concentrations (Chapter 2) of SF along with different electrospinning techniques (Chapter 3) on the structure of electrospun scaffolds and whether those scaffolds provide suitable microenvironments for mammary epithelial cells as determined by MCF10A cell attachment, viability, and structure formation. Further, we investigated the effects of the key ECM proteins collagen I (Chapter 4) and laminin (Chapter 5) used to blend or coat, respectively, SF scaffolds on the attachment, viability and structure formation of mammary epithelial cells. Our studies first highlight the mechanical and physical properties of the different SF-derived scaffolds through various SF concentrations and electrospinning techniques. Second, the biocompatibility of these SF electrospun scaffolds was defined based on MCF10A cell survival and adhesion. Third, our data indicate that scaffolds derived from blended and/or coated SF with collagen I also promoted human mammary cell survival and adhesion. Lastly, our observations suggest that on laminin-coated SF scaffolds MCF10A mammary cells, in the presence of lactogenic hormones, differentiated forming acinus-like structures. Overall, these studies provide evidence that SF electrospun scaffolds closely mimic the structure of the ECM fibers and allow many advantages such as; physical and chemical modification of the microenvironment by varying electrospinning parameters and addition of various proteins, hormones, and growth factors, respectively. Further, coating these SF scaffolds with essential ECM proteins, in particular laminin, promote cell-ECM interactions necessary for cell differentiation and formation of growth-arrested structures, through providing cell integrin binding sites and appropriate chemical cues.

Nowadays, exceptional advantages of silk fibroin over synthetic and natural polymers have impelled the scientists to application of this biomaterial for tissue engineering purposes. Recently, we showed that embedding natural degummed silk fibers in regenerated Bombyx mori silk-based scaffold significantly increases the mechanical stiffness, while the porosity of the scaffolds remains the same. In the present study, we evaluated degradation rate, biocompatibility and regenerative properties of the regenerated 2% and 4% wt silk-based composite scaffolds with or without embedded natural degummed silk fibers within 90 days in both athymic nude and wild-type C57BL/6 mice through subcutaneous implantation. In all scaffolds, a suitable interconnected porous structure for cell penetration was seen under scanning electron microscopy. Compressive tests revealed a functional relationship between fiber reinforcement and compressive modulus. In addition, the fiber/fibroin composite scaffolds support cell attachment and proliferation. On days 30 to 90 after subcutaneous implantation, the retrieved tissues were examined via gross morphology, histopathology, immunofluorescence staining and reverse transcription-polymerase chain reaction as shown in Figure 1. Results showed that embedding the silk fibers within the matrix enhances the biodegradability of the matrix resulting in replacement of the composite scaffolds with the fresh connective tissue. Fortification of the composites with degummed fibers not only regulates the degradation profile but also increases the mechanical performance of the scaffolds. This report also confirmed that pore size and structure play an important role in the degradation rate. In conclusion, the findings of the present study narrate key role of additional surface area in improving in vitro and in vivo biological properties of the scaffolds and suggest the potential ability of these fabricated composite scaffolds for connective tissue regeneration.

Silk fibroin is a widely studied material in the context of tissue engineering. Thanks to its versatility and impressive properties, the fields where silk fibroin is used have grown. In particular, silk fibroin has proved to be useful in all the cases when an interface with living tissues is needed (e.g. biophotonics, bioelectronics). As a consequence of this increasing interest, a wide range of protocols have been developed to prepare different materials starting from cocoons. The aim of this thesis is to investigate new strategies to fabricate silk fibroin-based materials, either improving previously developed protocols or proposing new methodologies both with the purpose to overcome certain limitations of current approaches and to propose new areas of application. We choose to work on three topics: the production of patterns using photolithography on a fibroin photoresist films (fibroin photocrosslinkable photoresist, FPP), the production of sponges made from a chemically modified version of the native protein (Methacrylated fibroin, Sil-MA), and the production of a solid bulk resin made starting from the regenerated protein. In the case of the FPP (and its counterpart made of sericine, SPP) the fabrication of films and pattern was restricted to the use of harsh chemicals. In addition, the resulting material had a roughness that limits its use in optical applications, making the determination of the refractive index (RI) not possible. The novelty of our work consisted in the modification of the original protocol to make it environmentally sustainable and to decrease the roughness in order to use ellipsometry to determine the RI dispersion. The broadly used silk-based sponges can be prepared by several protocols but they all suffer of the same limitations: the sponges are stabilized only by physical crosslinking (the change from the random to the crystalline secondary structure), and there are no clear models that correlate the sponge properties to their composition. We produced a new sponge, chemically crosslinked, whose stability was ensured by the creation, of chemical bonds between the protein chains during an UV curing. This task was accomplished using a simple protocol and a statistical method to model the composition-properties relations. The possibility to obtain a bulk, non-porous solid monolith from fibroin (solid-fibroin) has been received attention only in the last few years. This material is produced by a transition from solution to solid through solvent evaporation, a very slow process that takes weeks to be completed. The advantage of this transition is that it occurs at room temperature, allowing the addition of thermally degradable molecules (e.g. enzymes). We were able to optimize a procedure to produce the same material by compression of a silk sponge at high pressure and low temperature. The advantage of this method is the lower amount of time required to produce the material, minutes instead of days.

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No. of bitstreams: 1 silva_rr_dr_araiq_par.pdf: 1063262 bytes, checksum: cc72dc79773da734cac767490756f56e (MD5) Previous issue date: 2016-05-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Nanoestruturas unidimensionais de telúrio (Te1D) na forma de whiskers, fios e hélices foram preparados com facilidade por uma síntese em etapa única na presença de solução aquosa de Pluronic® F68 à baixas temperaturas (< 100 °C) e pressão ambiente. A forma das nanoestruturas puderam ser controladas de acordo com a cinética da reação. Estruturas empacotadas de nanowhiskers e nanofios de Te foram obtidas via auto-organização em interface líquido-líquido e pela técnica de drop-cast em substrato de Si/SiO2. Estruturas híbridas 1D foram obtidas utilizando nanoestruturas Te1D como molde de sacrifício para anexar nanopartículas metálicas ou mesmo produzir nanoestruturas 1D metálicas. Por exemplo, nanoestruturas híbridas 1D foram preparadas decorando nanofios de Te com nanopartículas de Ag em solução aquosa de poli(vinilpirrolidona). Nanoestruturas 1D de Au com forma de nódulos foram preparados por deslocamento galvânico de íons Au3+ em uma mistura de nanohélices de Te, ácido ascórbico e solução aquosa de poli(vinilpirrolidona). Além disso, nanohélices de Te foram funcionalizadas com uma camada resina resorcinol-formaldeído em condições brandas de síntese. A resina de resorcinol-formaldeído é uma via intermédia para explorar a deposição de compostos opticamente ativos tais como nanopartículas de hidroxicarbonato de Tb3+ ou nanopartículas de Au. Para aplicações práticas é essencial que estas nanoestruturas possam ser suportadas em filmes rígidos ou flexíveis de alta qualidade óptica. Filmes de polímeros naturais puros e filmes híbridos de sol-gel epóxi foram avaliados como potenciais matrizes hospedeiras para luminóforos. A fabricação de híbridos é baseada na incorporação de 3-glicidoxipropiltrimetoxissilano na solução homogênea de polímero natural com posterior secagem sobre uma superfície plana. Particularmente, filmes flexíveis de fibroína da seda e acetato de celulose e os seus híbridos derivados exibiram excelentes propriedades ópticas para hospedar compostos opticamente ativos. Por exemplo, compostos de Eu3+ emissores na região do vermelho e corantes fluorescentes foram incorporados em matriz pura de polímero e híbridos epóxi e suas propriedades ópticas foram investigadas. Laser de corantes por feedback distribuído (DFB) foram fabricados dopando grades de difração de fibroína de seda com Rodamina 6G. Devido a sua capacidade de replicar superfícies padronizadas com resolução nanométrica, grades de fibroina da seda dopadas com corante foram depositadas contra a grade de difração de uma mídia de disco compacto comercial. Lasers modificados de DFB baseados em filmes de fibroina contendo nanopartículas espalhadoras de luz de SiO2 e Ag aleatoriamente distribuídas na grade de fibroina demonstraram aumento da intensidade do laser, além de estreitamento da largura do pico de emissão. Filmes híbridos flexíveis e transparentes (> 85%) de fibroina da seda e acetato de celulose modificados com função epóxi e contendo compostos fluorescentes na região do vermelho como complexos β-dicetonato de Eu3+ e nanopartículas de YVO4:Eu3+ em baixa proporção relativa mássica (<5%) foram preparados. De maneira geral, o resultado são filmes homogêneos com funções epoxi e/ou alcoxissilano não hidrolisados disponíveis para outras modificações químicas. Devido a matéria-prima limitada de polímeros naturais para uma alta demanda de fabricação de dispositivos ópticos, é igualmente importante desenvolver materiais com base na reutilização de polímeros sintéticos. Filmes finos de poliestireno foram concebidos por dissolução de poliestireno expandido (EPS) recuperado de resíduos em D-limoneno, um solvente verde proveniente de óleos cítricos. Filmes transparentes dopados com complexos β-dicetonato de Eu3+ demonstraram excelente transparência e aptos para uso em guias de luz. Estes resultados são motivadores para a) a engenharia de nanoestruturas 1D com propriedades ópticas sintonizáveis bem como, b) desenvolvimento de híbridos flexíveis e transparentes baseados em híbridos de polímeros naturais com alta funcionalidade química ou polímeros sintéticos reciclados como potenciais matrizes hospedeiras ópticas almejadas em aplicações fotônicas. / One-dimensional Te nanostructures (Te1D) in the shape of whiskers, wires and helices were prepared by a facile one-pot synthesis in the presence of aqueous Pluronic® F68 solution at low temperatures (< 100 ºC) and ambient pressure. The shape of Te1D nanostructures could be manuvered according with the reaction kinectics. We evaluate some techniques to assemble Te1D nanostructures on the pursuit for complex nanoarchitectures. Bundles of Te nanowhiskers and nanowires were achieved by self-assembly in liquid-liquid interface or by drop-cast technique in Si/SiO2 substrates. 1D hybrid structures have been conceived by using Te1D nanostructures as sacrificial template to attach metallic nanoparticles or even produce metallic 1D nanostructures. For example, 1D hybrid nanostructures were easily prepared by decorating Te nanowires with Ag nanoparticles in aqueous solution of poly(vinylpyrrolidone). Au 1D nanostructures with nodular-like shape were prepared by galvanic displacement of Au3+ ions in a mixture of Te nanohelices, ascorbic acid and an aqueous solution of poly(vinylpyrrolidone). Furthermore, Te1D nanohelices were functionalized with a layer of resorcinol-formaldehyde resin at mild synthesis conditions. The RF resin allowed us to fashion an intermediate pathway to explore the deposition of optically active compounds like Tb3+ hydroxylcarbonate or Au nanoparticles. Seeking practical applications, these nanostructures should be hosted over rigid or flexible films possessing excellent optical properties. Pure natural polymers and epoxy sol-gel hybrids films were evaluated as potential host for luminophors. The fabrication of epoxy hybrids is based on the incorporation of 3-glycidoxypropyltrimethoxysiloxane on the homogenous solution of natural polymer with subsequent casting over flat surface. Particularly, flexible silk fibroin and cellulose acetate films and their derivative hybrids displayed excellent optical properties to host optically active compounds. For instance, red emitting Eu3+ compounds and fluorescent dyes were hosted on pure natural polymer and hybrid films and the optical features of the luminescent films were investigated thoroughly. Distributed feedback dye-lasers were fabricated by doping silk fibroin diffraction gratings with Rhodamine 6G. Owing its ability to mimic patterned surfaces at nanoscale resolution, dye-doped SF gratings were fabricated using replica-casting patterning against a commercial blank digital versatile disc as template. A modified DFB Laser based on SF films with Ag or SiO2 light scattering particles randomly distributed on the grating unveiled an enhancement of laser intensity withal narrowing of emission peak linewidth. Flexible and highly transparent SF- and CA-epoxy hybrids (> 85%) containing red fluorescent Eu3+ b-diketonate complex and YVO4:Eu3+ nanoparticles at low relative content (< 5 wt%) were tailored. In general, the outcome is homogeneous films with epoxy and/or unhydrolized alkoxysilane functions available for further chemical modification. Owing the limited feedstock of natural polymers for high demanding production of optical devices, it is equally important develop materials based on the reuse of synthetic polymers. Thin films of polystyrene were conceived by dissolving waste-recovered expanded-polystyrene (EPS) in D-limonene, a green solvent from citrus oil. Transparent EPS films doped with Eu3+ b-diketonate complex displayed excellent transparency and light waveguiding, These assertions provide a framework that motivates the research on a) engineering of 1D hybrids nanostructures with tunable optical properties and b) flexible natural polymer/epoxy hybrid with enhanced functionality or plastic recycled as potential optical hosts sought in photonic applications. / FAPESP: 2013/12367-6