Människor har olika förutsättningar för att hitta i sin köksmiljö beroende på vilket hälsotillstånd som ligger till grund för den enskilde individen. Det finns personer som har ett försämrat arbetsminne på grund av att de fått diagnosen lindrig Alzheimers sjukdom. Idag ger många köksluckor ingen information om innehållet, och i varje enskild individs kök finns det olika objekt beroende på vad som används. Denna studie handlar om att hitta olika former av åtgärder i köksmiljöer för att lättare kunna hitta, det finns en förhoppning av att problemen med att inte hitta kan minska. Att använda datainsamlingstekniker som litteratur, intervjuer, workshop och fokusgrupp ska det gå att få reda på vilka åtgärder som kan fungera. Resultaten visar på att det finns problem, och dessa är tänkt att lösa med olika åtgärdsförslag. De förslag som framkommit som kognitiva stöd är bland annat, öppna planlösningar, individuella bilder och transparanta luckor.

This research centers on the fabrication, characterization, and engineering of inverse opal scaffolds, a novel class of three-dimensional (3D) porous scaffolds made of biocompatible and biodegradable polymers, for applications in tissue engineering and regenerative medicine. The unique features of an inverse opal scaffold include a highly ordered array of pores, uniform and finely tunable pore sizes, high interconnectivity, and great reproducibility. The first part of this work focuses on the fabrication and functionalization of inverse opal scaffolds based on poly(D,L-lactic-co-glycolic acid) (PLGA), a biodegradable material approved by the U.S. Food and Drug Administration (FDA). The advantages of the PLGA inverse opal scaffolds are also demonstrated by comparing with their counterparts with spherical but non-uniform pores and poor interconnectivity. The second part of this work shows two examples where the PLGA inverse opal scaffolds were successfully used as a well-defined system to investigate the effect of pore size of a 3D porous scaffold on the behavior of cell and tissue growth. Specifically, I have demonstrated that i) the differentiation of progenitor cells in vitro was dependent on the pore size of PLGA-based scaffolds and the behavior of the cells was determined by the size of individual pores where the cells resided in, and ii) the neovascularization process in vivo could be directly manipulated by controlling a combination of pore and window sizes when they were applied to a mouse model. The last part of this work deals with the novel application of photoacoustic microscopy (PAM), a volumetric imaging modality recently developed, to tissue engineering and regenerative medicine, in the context of non-invasive imaging and quantification of cells and tissues grown in PLGA inverse opal scaffolds, both in vitro and in vivo. Furthermore, the capability of PAM to monitor and quantitatively analyze the degradation of the scaffolds themselves was also demonstrated.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-04-16T19:44:01Z No. of bitstreams: 1 WILLIAMS TELES BARBOSA - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2309358 bytes, checksum: 60fe4478ffb44784348a9ae62c055d89 (MD5) / Made available in DSpace on 2018-04-16T19:44:01Z (GMT). No. of bitstreams: 1 WILLIAMS TELES BARBOSA - DISSERTAÇÃO PPG-CEMat 2014..pdf: 2309358 bytes, checksum: 60fe4478ffb44784348a9ae62c055d89 (MD5) Previous issue date: 2015-02-25 / Capes / Biocerâmicas porosas são utilizadas para fornecer local onde o tecido ósseo possa crescer e fixar o implante biologicamente. A hidroxiapatita [HA, Ca10(PO4)6(OH)2] é um fosfato de cálcio que tem recebido atenção considerável nas últimas duas décadas como material de implante. Devido à sua ocorrência natural no tecido ósseo, os fosfatos de cálcio possuem boas propriedades de biocompatibilidade e osteocondução, tornando-a um dos biomateriais mais promissores na fabricação de scaffolds para a engenharia de tecido ósseo. O objetivo do presente trabalho centrou-se no desenvolvimento e otimização de estruturas tridimensionais porosas a base de HA combinando o método Sol-Gel e a réplica da esponja de poliuretano (PU), permitindo uma interconectividade e distribuição variada dos poros. Os scaffolds desenvolvidos foram caracterizados pelas técnicas de Espectroscopia na Região do Infravermelho com Transformada de Fourier (FTIR), Difração de Raios X (DRX), Microscopia Eletrônica de Varredura (MEV), Espectroscopia por Energia Dispersiva de Raios X (EDS), Análise Termogravimétrica (TG), Porosidade, Ensaio de Compressão. Os resultados de FTIR apresentaram as bandas características da HA. A técnica de DRX revelou a presença da fase cristalina de HA (95%), como também em menor quantidade o α-Fosfato Tricálcico (2,5%). As análises por MEV revelaram scaffolds com poros interconectados com tamanhos de poros variando entre 50µm a 200μm e o EDS detectou a presença dos elementos químicos característicos da HA, como o Cálcio e o Fósforo. Os resultados de TG permitiram confirmar que as curvas de temperatura utilizadas no processo de sinterização, são eficientes para a queima da esponja, obtendo-se somente uma fase inorgânica de apatita. Os scaffolds apresentaram uma porosidade total de aproximadamente 75% e resistência à compressão variando de 3,13 a 4,86 MPa. Diante dos resultados obtidos foi possível produzir scaffolds de apatita através da metodologia Sol-Gel e combinação com a metodologia de replica de esponja porosa, com características que devem permitir a regeneração óssea. / Porous bioceramics are used to provide location where the bone tissue can grow and biologically fixing the implant. Hydroxyapatite [HA, Ca10(PO4)6(OH)2] is a calcium phosphate which has received considerable attention over the past two decades as an implant material. Due to its naturally occurring in bone tissue, the calcium phosphate has good biocompatibility and osteoconductive properties, making it one of the most promising biomaterials in the manufacture of scaffolds for bone tissue engineering. The objective of this work was the development and optimization of porous three-dimensional structures composed of HA, combining sol-gel method with the replica of a polyurethane foam, allowing interconnectivity and scattered distribution of pores. The developed scaffolds were characterized by Fourier Transform in the Infrared Region (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Thermogravimetric Analysis (TG), Porosity Tests and Compression Tests. The FTIR results showed the characteristic bands of the hydroxyapatite. The XRD technique revealed the presence of a crystalline phase belonging to hydroxyapatite (97,5%), and to a lesser extent the α-Tricalcium Phosphate (2,5%). Analysis by SEM revealed scaffolds with interconnected pores which had sizes ranging from 50μm to 200μm and EDS detected the presence of specific chemical elements of hydroxyapatite such as Calcium and Phosphorus. TG results allowed to confirm that the temperature curves used in the sintering process, is effective for burning of the sponge, yielding only an inorganic phase of apatite. The scaffolds showed a porosity of about 75% and compressive moduli ranging from 3.13 to 4.86 MPa. Based on these results, it was possible to produce scaffolds of HA by Sol-Gel method in combination with replica of a polyurethane foam, with attributes for bone regeneration.

L’ingénierie tissulaire osseuse a récemment connu de nouveaux développements grâce à la prise en compte du phénomène de mécanotransduction dans la conception des bioréacteurs. Toutefois, des progrès restent à faire sur nos connaissances sur les mécanismes de la réponse des cellules souches mésenchymateuses (CSM) aux contraintes mécaniques en vue d’optimiser l’environnement mécanique tridimensionnel des cellules dans les bioréacteurs. L’objectif de cette thèse est double : déterminer le meilleur microenvironnement mécanique pour des CSM humaines et appliquer cet environnement au sein d’un bioréacteur. Pour cela, des CSM humaines ont été cultivées dans différentes conditions et soumises à des contraintes mécaniques. Leur réponse a été analysée via des marqueurs précoces de l’ostéogénèse. En parallèle, un modèle numérique a été développé pour simuler l’écoulement dans un bioréacteur à scaffold granulaire et déterminer le niveau et la répartition des contraintes ressentis par les cellules. Il a été mis en évidence que la réponse des cellules à une stimulation mécanique dépend très fortement de son environnement tridimensionnel. Ce travail à la fois mécanique et biologique permet de dégager des pistes d’amélioration des bioréacteurs et des scaffolds en vue de l’optimisation de l’environnement mécanique tridimensionnel des cellules en ingénierie tissulaire osseuse. / Bone tissue engineering is currently in full development and a growing field of research. The consideration of the mechanotransduction process is a key factor in the optimization of bioreactors. Mesenchymal stem cells (MSC) used in bone tissue engineering are known to be mechanosensitive but our knowledge of the mechanisms of cell response to mechanical stress needs to be improved. This thesis has a double goal: determining the best possible mechanical microenvironment for human MSC, and apply this environment in a bioreactor. To that aim, human MSC were grown in different conditions and subjected to mechanical stresses. Their response was analyzed through osteogenesis markers. A numerical model was also implemented to simulate the flow in bioreactor with a granular scaffold and evaluate levels and distributions of stresses felt by cells. It was shown that cell response to mechanical stress is strongly dependent on the tridimensional environment. This biological and mechanical study highlights tracks of improvement for bioreactors and scaffolds to optimize the mechanical tridimensional environment of cells in bone tissue engineering.

Um eine verbesserte Therapieoption mit weniger Schmerzen und Nebenwirkun-gen für Patienten mit Depigmentierungsstörungen wie Vitiligo zu entwickeln, wurde eine Methode zur nichtinvasiven Gewinnung von autologen Melanozyten aus der Haarwurzel genutzt. Die Haarwurzel als einfach zugängliches Stammzell-reservoir bietet die Möglichkeit, Vorläufermelanozyten aus der äußeren Haar-wurzelscheide zu isolieren, differenzieren und zu proliferieren. Für zukünftige autologe Transplantationsversuche wurden in dieser Arbeit die kultivierten hu-manen Melanozyten aus der äußeren Haarwurzelscheide (Human Melanocytes from the Outer Root Sheath, HUMORS) auf drei unterschiedlichen Scaffolds getes-tet. Hinsichtlich mitochondrialer Aktivität (Marker für Zellproliferation), mela-nozytenspezifischer Markerexpression und ihrer Funktionalität (Tyrosinase-Enzymaktivität und Melaningehalt) wurden die Zellen auf Collagen Cell Carrier® (CCC), Poly-ε-Caprolacton-Scaffolds (PCL) und kollagen basierten Hydrogelen (cGEL) kultiviert und charakterisiert. Alle Scaffolds waren biokompatibel, immu-nologisch nur gering aktiv und wiesen eine dreidimensionale Struktur auf, die der extrazellulären Matrix nachempfunden war. Einen positiven Effekt auf die Prolife-ration wiesen die HUMORS auf den Collagen Cell Carrier® auf. Bei Untersuchun-gen der melanotischen Aktivität überzeugten die HUMORS auf dem cGEL Typ4 durch einen signifikant höheren Melaningehalt. Da Melanin das entscheidende Produkt der Repigmentierung bei Vitiligoläsionen ist, stellte sich damit das cGEL Typ4 als vielversprechender Zellträger für die Kultivierung und vorgesehene Transplantation der Melanozyten heraus.

<p dir="ltr">The goal of this work is to enhance acceptance of cultured meat by replicating traditional meat behavior. This research focuses on the design, manufacture, and mechanics of scaffolds, which provide essential structural support for cell alignment and tissue formation in cultured meat. The integration of biopolymer scaffolds in the final product necessitates a thorough understanding of the thermo-mechanical behavior of scaffolding materials during critical stages like culturing and cooking. Two primary studies were conducted using additive manufacturing processes: (1) vat polymerization and (2) fused filament fabrication. A novel sustainable photocurable soy-based resin was evaluated for high-temperature degradation. The key challenge was ensuring printability and understanding the curing kinetics of the soy resin. For fused filament fabrication, the approach employed an innovative manufacturing-for-design paradigm aimed at mimicking the contraction properties of meat during cooking. The geometry, material properties, and printing process gave rise to a class of novel metamaterials with tunable negative thermal expansions. The key results showed that the thermo-mechanical behavior of soy-based scaffolds could be assessed without the need for costly and time-consuming culturing, as heat did not compromise structural integrity. Furthermore, cooking semi-crystalline biopolymers in an aqueous environment led to material crystallization, which altered the expected deformation mechanisms in the scaffolds. This unexpected behavior was captured in an analytical model accounting for non-linear material properties and print process parameters. By understanding the impact of manufacturing techniques on scaffold behavior, this work established a critical process-property-performance relationship for cultured meat production.</p>

Master of Science / Department of Industrial & Manufacturing Systems Engineering / Shuting Lei / Polyglycolic acid (PGA) is an important polymer in the field of tissue engineering. It has many favorable properties such as biocompatibility, bioabsorbability, high melting point, low solubility in organic solvents, high tensile strength and is used in a variety of medical related applications. Currently there are various methods such felting, stitching, use of binder/adhesive for joining the non woven meshes of PGA polymer in order to make suitable three dimensional scaffolds. The existing methods for joining the non woven meshes of PGA polymer are usually time consuming and not very flexible. Thus there is a need for a better technique that would overcome the drawbacks of the existing methods. Laser welding offers potential advantages such as high welding rates, easy to automate, improved seam and single sided access such that welds can be performed under various layers of fabric. Therefore, the main objective of this research is to conduct a fundamental study on laser welding of non woven PGA scaffold felts. An experimental setup for spot welding is built that would assist in the formation of tubular structures. A factorial design of experiments is used to study the effects of the operating parameters such as laser power, beam diameter, time duration and pressure on the weld quality. The weld quality is assessed in terms of weld strength and weld diameter. Based on the parametric study, a regression analysis is carried out to form correlations between weld quality and the operating parameters, which could be used to select the optimal operating conditions. The successful welds obtained by the laser welding process have no discoloration and are stronger than the tensile strength of the original non woven sheets of PGA biofelt.

Bone and cartilage constructs are often plagued with mechanical failure, poor nutrient transport, poor tissue ingrowth, and necrosis of embedded cells. However, advances in computer aided design (CAD) and computational modeling enable the design of scaffolds with complex internal michroarchitectures and the a priori prediction of their transport and mechanical properties, such that the design of constructs satisfying the needs of the tissue environment can be optimized. The goal of this research is to investigate the capability of additive manufacturing technologies to create designed microarchitectured tissue engineering scaffolds for bone and cartilage regeneration. This goal will be achieved by pursuing the following two objectives: (1) the manufacture of bioresorbable thermoplastic scaffolds by selective laser sintering (SLS) (2) and the manufacture of hydrogel scaffolds by large area maskless photopolymerization (LAMP). SLS is a laser based additive manufacturing method in which an object is built layer-by-layer by fusing powdered material using a computer-controlled scanning laser. LAMP is a massively parallel ultraviolet curing-based process that can be used to create hydrogels from a photomonomer on a large-scale (558x558mm) while maintaining extremely high feature resolution (20µm). In this research, SLS is used to process polycaprolactone (PCL) and composites of PCL with hydroxyapatite (HA) for bone tissue engineering applications while LAMP is used to process polyethylene glycol diacrylate (PEGDA) which can be used for hard and soft tissue applications.

<p>Articular cartilage is a connective tissue that lines the surfaces of diarthrodial joints; and functions to support and distribute loads as wells as facilitate smooth joint articulation. Unfortunately, cartilage possesses a limited capacity to self-repair. Once damaged, cartilage continues to degenerate until widespread cartilage loss results in the debilitating and painful disease of osteoarthritis. Current treatment options are limited to palliative interventions that seek to mitigate pain, and fail to recapitulate the native function. Cartilage tissue engineering offers a novel treatment option for the repair of focal defects as well as the complete resurfacing of osteoarthritic joints. Tissue engineering combines cells, growth factors, and biomaterials in order to synthesize new cartilage tissue that recapitulates the native structure, mechanical properties, and function of the native tissue. In this endeavor, there has been a growing interest in the use of scaffolds derived from the native extracellular matrix of cartilage. These cartilage-derived matrix (CDM) scaffolds have been show to recapitulate the native epitopes for cell-matrix interactions as well as provide entrapped growth factors; and have been shown to stimulate chondrogenic differentiation of a variety of cell types. Despite the potent chondroinductive properties of CDM scaffolds, they possess very weak mechanical properties that are several orders of magnitude lower than the native tissue. These poor mechanical properties lead to CDM scaffolds succumbing to cell-mediated contraction, which dramatically and unpredictably alters the size and shape of CDM constructs. Cell-mediated contraction not only prevents the fabrication of CDM constructs with specific, pre-determined dimensions, but also limits cellular proliferation and metabolic synthesis of cartilage proteins. This dissertation utilized collagen crosslinking techniques as well as ice-templating in order to enhance the mechanical properties of CDM scaffolds and prevent cell-mediated contraction. Furthermore, the decellularization of CDM was investigated in order to remove possible sources of immunogenicity. This work found that both physical and chemical crosslinking techniques were capable of preventing cell-mediated contraction in CDM scaffolds; however, the crosslinking techniques produced distinct effects on the chondroinductive capacity of CDM. Furthermore, the mechanical properties of CDM scaffolds were able to be enhanced by increasing the CDM concentration; however, this led to a concomitant decrease in pore size, which limited cellular infiltration. The pore size was able to be rescued through the use of an ice-templating technique that led to the formation of large aligned grooves, which enabled cellular infiltration. Additionally, a decellularization protocol was developed that successfully removed foreign DNA to the same order of magnitude as clinically approved materials, while preserving the native GAG content of the CDM, which has been shown to be critical in preserving the mechanical properties of the CDM. Altogether, this body of work demonstrated that dehydrothermal crosslinking was best suited for maintaining the chondroinductive capacity of the CDM, and given the appropriate scaffold fabrication parameters, such as CDM concentration and ice-templating technique, dehydrothermal treatment was able to confer mechanical properties that prevented cell-mediated contraction. To emphasize this finding, this work culminated in the fabrication of an anatomically-relevant hemispherical scaffold entirely from CDM alone. The CDM hemispheres not only supported chondrogenic differentiation, but also retained the original scaffold dimensions and shape throughout chondrogenic culture. These findings illustrate that CDM is a promising material for the fabrication of tailor-made scaffolds for cartilage tissue engineering.</p> / Dissertation

Orientador: Elenice Deffune / Banca: Sérgio Luis Felisbino / Banca: João Tadeu Ribeiro Paes / Resumo: Levando-se em consideração avanços tecnológicos na área médica e o impacto dos programas de saúde que determinaram curvas de longevidade cada vez maiores e taxas de natalidade cada vez menores, o novo desafio do gestor público são as conseqüências: o envelhecimento e a vida como uma "doença crônica". Entre os principais desafios está a abordagem das doenças crônico-degenerativas que determinam o aumento de lesões cartilaginosas articulares. A débil capacidade de regeneração e as limitações das alternativas de tratamento fazem as técnicas derivadas da biotecnologia, como o transplante autólogo de condrócitos (TAC) e o uso de células-tronco, o foco das investigações. O TAC requer coleta de material cartilaginoso de área sadia, podendo causar nova lesão; no entanto, pode-se evitar este perigo com o uso de células-tronco. As células-tronco mesenquimais, adultas, podem se diferenciar em condrócitos mediante o uso de meio de cultura específico em consonância a um arcabouço 3D, mas muitos problemas como evitar a calcificação e estimular a condrogênese em meio favorável constituem o desafio para os pesquisadores na atualidade. 1) produzir anticorpo monoclonal específico a CTMs de coelho para monitorá-las, 2) determinar o volume ideal de coleta de medula óssea para microencapsulação e condrogênese, 3) realizar a microencapsulação das CTMs em novos arcabouços: BIOGEL3D e BACTCELL3D, comparando seu desempenho com o modelo clássico em alginato. Foram utilizados 25 coelhos Nova Zelândia sendo divididos em diferentes grupos em função do volume de MO coletado: G1 = 6mL, G2 = 9mL, G3 = 12mL, G4 = 15mL e G5 = volume ideal de coleta determinado pelos indicadores dos outros grupos. O material coletado foi diluído 1:2 em RPMI 1640 com 3.000U de heparina sódica. Após a contagem celular, as amostras foram submetidas a separação em gradiente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Technological advances in the medical area combined with the impact of health programs that enhance longevity, together with lower natality rates created new challenges to the public manager such as aging and life as a "chronic disease". Among the major problems are the chronic degenerative diseases that increase articular lesions. The limited regeneration capabilities and the limitations of actual treatment alternatives made biotechnology derived techniques the focus of investigations. The autologous chondrocyte transplantation (ACT) requires a small biopsy of health cartilage, which can lead to a new lesion. However, the use of stem cells can avoid this possibility. Mesenchymal stem cells (MSCs) can differentiate into chondrocytes by using a specific culture medium together with a 3D scaffold, but some questions such as the risks of calcification remain as key factors to researchers. 1) to produce a monoclonal antibody that recognizes MSCs in order to characterize them, 2) to determine the optimal bone marrow collection volume for cell microencapsulation and chondrogenesis and 3) to microencapsulate MSCs in two novel scaffolds: BIOGEL3D and BACTCELL3D, comparing them with sodium alginate. 25 New Zealand rabbits were divided into 5 groups related to bone marrow collection volume: G1 = 6mL, G2 = 9mL, G3 = 12mL, G4 = 15mL and G5 = optimal volume determined by the study. The collected material was diluted in RPMI1640 medium 1:2, with 3000U sodium heparin. After cell count and viability assessment the samples were submitted to density gradient centrifugation in order to isolate the lymphomononuclear (LMN) fraction. These cells were seeded to obtain and expand the MSCs in DMEM Knockout® (InvitrogenTM) supplemented with antibiotic/antimycotic, Lglutamine, essential aminoacids, non essential aminoacids and fetal bovine serum (all from InvitrogenTM). The cells were cultivated in 5% CO2 ...(Complete abstract click electronic access below) / Mestre