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Estudo das propriedades biocompatíveis de arcabouços poliméricos derivados de óleos vegetais para aplicação na engenharia de tecidos; Study of biocompatible properties of polymeric scaffolds derivated from vegetable oil for tissue engineering

Baratéla, Fernando José Costa
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 03/07/2015 PT
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66.1%
A engenharia de tecidos e a medicina regenerativa possuem como objetivo principal o restabelecimento morfológico/funcional de tecidos e órgãos lesionados com a utilização de células, matrizes celulares e células tronco, controlando as respostas imunológicas/bioquímicas promovidas pelo organismo. Adicionalmente, a ciência dos materiais busca desenvolver biomateriais biocompatíveis que não promovam reações imunológicas indesejadas e proporcionem o reestabelecimento das funções do tecido/órgão. Polímeros de origem natural destacam-se como biomateriais por assemelharem-se a macromoléculas biológicas, similaridade com a matriz extracelular, menor possibilidade de estimulação de inflamação crônica e baixa ou ausência de toxicidade. O presente trabalho teve como objetivo desenvolver matrizes macromoleculares originadas do óleo de soja epoxidado (OSE), analisando a relação estrutura química/atividade biológica das matrizes macromoleculares para uso como biomaterial na engenharia de tecidos. A síntese do OSE foi efetuada pela rota oleoquímica, cuja eficiência foi determinada por espectroscopia de infravermelho e o rendimento da reação de 85% determinado por ressonância magnética nuclear de prótons. A partir da análise por calorimetria exploratória diferencial...

Tissue engineering: Using collagen type i matrix for bone healing of bone defects

Oliveira, Marina Reis; Das Graças Martins, Elisa; Célio-Mariano, Ronaldo; Sonoda, Celso K.; Garcia, Idelmo Rangel; De Melo, Willian Morais
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
66.11%
Among the many tissues in the human body, bone has been considered as a powerful marker for regeneration and its formation serves as a prototype model for tissue engineering based on morphogenesis. Therefore, collagen type I is one of the most useful biomaterials used in tissue engineering as extracellular matrix components capable to promote bone healing. The literature reveals excellent biocompatibility and safety due to its biological characteristics, such as biodegradability and weak antigenicity, making collagen type I the primary resource in medical applications. Thus, it was also used for tissue engineering including skin replacement, bone substitutes, and artificial blood vessels and valves. The authors describe the treatment of an abscessed apical periodontal cyst and show good outcomes of bone healing, using tissue engineering, as collagen type I matrix. © 2013 by Mutaz B. Habal, MD.

Alternative tissue engineering scaffolds based on starch: processing methodologies, morphology, degradation and mechanical properties

Gomes, Manuela E.; Godinho, J. S.; Tchalamov, D.; Cunha, A. M.; Reis, R. L.
Fonte: Elsevier Science Publicador: Elsevier Science
Tipo: Artigo de Revista Científica
Publicado em //2002 ENG
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66.12%
An ideal tissue engineering scaffold must be designed from a polymer with an adequate degradation rate. The processing technique must allow for the preparation of 3-D scaffolds with controlled porosity and adequate pore sizes, as well as tissue matching mechanical properties and an appropriate biological response. This communication revises recent work that has been developed in our laboratories with the aim of producing 3-D polymeric structures (from starch-based blends) with adequate properties to be used as scaffolds for bone tissue engineering applications. Several processing methodologies were originally developed and optimised. Some of these methodologies were based on conventional melt-based processing routes, such as extrusion using blowing agents (BA) and compression moulding (combined with particulate leaching). Other developed technologies included solvent casting and particle leaching and an innovative in situ polymerization method. By means of using the described methodologies, it is possible to tailor the properties of the different scaffolds, namely their degradation, morphology and mechanical properties, for several applications in tissue engineering. Furthermore, the processing methodologies (including the blowing agents used in the melt-based technologies) described above do not affect the biocompatible behaviour of starch-based polymers. Therefore...

Scaffolds based bone tissue engineering : the role of chitosan

Costa-Pinto, A. R.; Reis, R. L.; Neves, N. M.
Fonte: Mary Ann Liebert Publicador: Mary Ann Liebert
Tipo: Artigo de Revista Científica
Publicado em //2011 POR
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66.16%
As life expectancy increases, malfunction or loss of tissue caused by injury or disease leads to reduced quality of life in many patients at significant socioeconomic cost. Even though major progress has been made in the field of bone tissue engineering, present therapies, such as bone grafts, still have limitations. Current research on biodegradable polymers is emerging, combining these structures with osteogenic cells, as an alternative to autologous bone grafts. Different types of biodegradable materials have been proposed for the preparation of three-dimensional porous scaffolds for bone tissue engineering. Among them, natural polymers are one of the most attractive options, mainly due to their similarities with extracellular matrix, chemical versatility, good biological performance, and inherent cellular interactions. In this review, special attention is given to chitosan as a biomaterial for bone tissue engineering applications. An extensive literature survey was performed on the preparation of chitosan scaffolds and their in vitro biological performance as well as their potential to facilitate in vivo bone regeneration. The present review also aims to offer the reader a general overview of all components needed to engineer new bone tissue. It gives a brief background on bone biology...

Natural origin biodegradable systems in tissue engineering and regenerative medicine : present status and some moving trends

Mano, J. F.; Silva, G. A.; Azevedo, Helena S.; Malafaya, P. B.; Sousa, R. A.; Silva, S. S.; Boesel, L. F.; Oliveira, Joaquim M.; Santos, T. C.; Marques, A. P.; Neves, N. M.; Reis, R. L.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em //2007 ENG
Relevância na Pesquisa
66.11%
The fields of tissue engineering and regenerative medicine aim at promoting the regeneration of tissues or replacing failing or malfunctioning organs, by means of combining a scaffold/support material, adequate cells and bioactive molecules. Different materials have been proposed to be used as both three-dimensional porous scaffolds and hydrogel matrices for distinct tissue engineering strategies. Among them, polymers of natural origin are one of the most attractive options, mainly due to their similarities with the extracellular matrix (ECM), chemical versatility as well as typically good biological performance. In this review, the most studied and promising and recently proposed naturally derived polymers that have been suggested for tissue engineering applications are described. Different classes of such type of polymers and their blends with synthetic polymers are analysed, with special focus on polysaccharides and proteins, the systems that are more inspired by the ECM. The adaptation of conventional methods or nonconventional processing techniques for processing scaffolds from natural origin based polymers is reviewed. The use of particles, membranes and injectable systems from such kind of materials is also overviewed...

Materials in particulate form for tissue engineering. 2 Applications in bone

Silva, G. A.; Coutinho, O. P.; Ducheyne, P.; Reis, R. L.
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
Publicado em //2007 ENG
Relevância na Pesquisa
66.12%
Materials in particulate form have been the subjects of intensive research in view of their use as drug delivery systems. While within this application there are still issues to be addressed, these systems are now being regarded as having a great potential for tissue engineering applications. Bone repair is a very demanding task, due to the specific characteristics of skeletal tissues, and the design of scaffolds for bone tissue engineering presents several difficulties. Materials in particulate form are now seen as a means of achieving higher control over parameters such as porosity, pore size, surface area and the mechanical properties of the scaffold. These materials also have the potential to incorporate biologically active molecules for release and to serve as carriers for cells. It is believed that the combination of these features would create a more efficient approach towards regeneration. This review focuses on the application ofmaterials in particulate formfor bone tissue engineering. A brief overview of bone biology and the healing process is also provided in order to place the application in its broader context. An original compilation of molecules with a documented role in bone tissue biology is listed, as they have the potential to be used in bone tissue engineering strategies. To sum up this review...

Starch-poly(epsilon-caprolactone) and starch-poly(lactic acid) fibre-mesh scaffolds for bone tissue engineering applications : structure, mechanical properties and degradation behaviour

Gomes, Manuela E.; Azevedo, Helena S.; Moreira, A. R.; Ellã, V.; Kellomaki, M.; Reis, R. L.
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
Publicado em //2008 ENG
Relevância na Pesquisa
66.12%
In scaffold-based tissue engineering strategies, the successful regeneration of tissues from matrixproducing connective tissue cells or anchorage-dependent cells (e.g. osteoblasts) relies on the use of a suitable scaffold. This study describes the development and characterization of SPCL (starch with !-polycaprolactone, 30 : 70%) and SPLA [starch with poly(lactic acid), 30 : 70%] fibre-meshes, aimed at application in bone tissue-engineering strategies. Scaffolds based on SPCL and SPLA were prepared from fibres obtained by melt-spinning by a fibre-bonding process. The porosity of the scaffolds was characterized by microcomputerized tomography (μCT) and scanning electron microscopy (SEM). Scaffold degradation behaviour was assessed in solutions containing hydrolytic enzymes ("-amylase and lipase) in physiological concentrations, in order to simulate in vivo conditions. Mechanical properties were also evaluated in compression tests. The results show that these scaffolds exhibit adequate porosity and mechanical properties to support cell adhesion and proliferation and also tissue ingrowth upon implantation of the construct. The results of the degradation studies showed that these starch-based scaffolds are susceptible to enzymatic degradation...

Relevance and safety of telomerase for human tissue engineering

Klinger, Rebecca Y.; Blum, Juliana L.; Hearn, Bevin; Lebow, Benjamin; Niklason, Laura E.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.11%
Tissue engineering holds the promise of replacing damaged or diseased tissues and organs. The use of autologous donor cells is often not feasible because of the limited replicative lifespan of cells, particularly those derived from elderly patients. Proliferative arrest can be overcome by the ectopic expression of telomerase via human telomerase reverse transcriptase (hTERT) gene transfection. To study the efficacy and safety of this potentially valuable technology, we used differentiated vascular smooth muscle cells (SMC) and vascular tissue engineering as a model system. Although we previously demonstrated that vessels engineered with telomerase-expressing SMC had improved mechanics over those grown with control cells, it is critical to assess the phenotypic impact of telomerase expression in donor cells, because telomerase up-regulation is observed in >95% of human malignancies. To study the impact of telomerase in tissue engineering, expression of hTERT was retrovirally induced in SMC from eight elderly patients and one young donor. In hTERT SMC, significant lifespan extension beyond that of control was achieved without population doubling time acceleration. Karyotype changes were seen in both control and hTERT SMC but were not clonal nor representative of cancerous change. hTERT cells also failed to show evidence of neoplastic transformation in functional assays of tumorigenicity. In addition...

Molecular Magnetic Resonance Imaging Approaches Used to Aid in the Understanding of the Tissue Regeneration Marker Met In Vivo: Implications for Tissue Engineering

Towner, Rheal A.; Smith, Nataliya; Asano, Yasuko; Doblas, Sabrina; Saunders, Debra; Silasi-Mansat, Robert; Lupu, Florea
Fonte: Mary Ann Liebert, Inc. Publicador: Mary Ann Liebert, Inc.
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.1%
The levels of Met, a tyrosine kinase receptor for the hepatocyte growth factor or scatter factor, are elevated during tissue regeneration, and can be used to assess tissue regeneration associated with engineered tissue grafts. This study involved the development and assessment of a novel magnetic resonance imaging (MRI) molecular probe for the in vivo detection of Met in an experimental rodent (rat) model of disease (C6 glioma). The implication of using these probes in tissue engineering is discussed. The molecular targeting agent we used in our study incorporated a magnetite-based dextran-coated nanoparticle backbone covalently bound to an anti-Met antibody. We used molecular MRI with an anti-Met probe to detect in vivo Met levels as a molecular marker for gliomas. Tumor regions were compared to normal tissue, and found to significantly (p < 0.05) decrease MR signal intensity and T2 relaxation in tumors. Nonimmune nonspecific normal rat IgG coupled to the dextran-coated nanoparticles was used as a control. Met levels in tumor tissues were confirmed in Western blots. Based on our results, in vivo evaluation of tissue regeneration using molecular MRI is possible in tissue engineering applications.

Molecular Magnetic Resonance Imaging Approaches Used to Aid in the Understanding of Angiogenesis In Vivo: Implications for Tissue Engineering

Towner, Rheal A.; Smith, Nataliya; Asano, Yasuko; He, Ting; Doblas, Sabrina; Saunders, Debra; Silasi-Mansat, Robert; Lupu, Florea; Seeney, Charles E.
Fonte: Mary Ann Liebert, Inc. Publicador: Mary Ann Liebert, Inc.
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
66.12%
In tissue engineering it is often necessary to assess angiogenesis associated with engineered tissue grafts. The levels of vascular endothelial growth factor receptor 2 (VEGF-R2) is elevated during angiogenesis. The goal of this study was to develop and assess a novel magnetic resonance imaging (MRI) molecular probe for the in vivo detection of VEGF-R2 in an experimental rodent model of disease. The possible use of the probe in tissue engineering applications is discussed. The molecular targeting agent we used in our study incorporated a magnetite-based dextran-coated nanoparticle backbone covalently bound to an anti-VEGF-R2 antibody. We used molecular MRI with an anti-VEGF-R2 probe to detect in vivo VEGF-R2 levels as a molecular marker for gliomas (primary brain tumors). Tumor regions were compared with normal tissue. Nonimmune nonspecific normal rat immunoglobulin G coupled to the dextran-coated nanoparticles was used as a control. Prussian blue staining for iron-based nanoprobes was used to confirm the specificity of the probe for VEGF-R2 in glioma tissue. VEGF-R2 levels in tumor tissues were also confirmed in western blots and via immunohistochemistry. Based on our results, in vivo evaluation of tissue angiogenesis using molecular MRI is possible in tissue engineering applications.

Biomimetic approach to cardiac tissue engineering

Radisic, Milica
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 147 leaves; 9512460 bytes; 9532223 bytes; application/pdf; application/pdf
EN_US
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66.12%
(cont.) biochemical and morphological properties in the pretreated group. Finally, in order to mimic capillary structure cardiac fibroblasts and myocytes were co-cultured on a scaffold with a parallel channel array that was perfused with culture medium supplemented with synthetic oxygen carrier (PFC emulsion). Presence of the PFC emulsion resulted in significantly higher cell density and improved contractile properties compared to the constructs cultivated in the culture medium alone, by increasing total oxygen content and effective diffusivity.; Heart disease is the leading cause of death in the Western world. Tissue engineering may offer alternative treatment options or suitable models for studies of normal and pathological cardiac tissue function in vitro. Current tissue engineering approaches have been limited by diffusional oxygen supply, lack of physical stimuli and absence of multiple cell types characteristic of the native myocardium. We hypothesized that functional, clinically sized (1-5 mm thick), compact cardiac constructs with physiologic cell densities can be engineered in vitro by mimicking cell microenvironment present in the native myocardium in vivo. Since cardiac myocytes have limited ability to proliferate we developed methods of seeding cells at high densities while maintaining cell viability. Cultivation of cardiac constructs in the presence of convective-diffusive oxygen transport in perfusion bioreactors...

Synthesis and microfabrication of elastomeric biomaterials for advanced tissue engineering scaffolds

Bettinger, Christopher John, 1981-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 252 leaves
ENG
Relevância na Pesquisa
66.12%
The subject of this thesis lies at the interface of microfabrication technology and advanced biomaterials synthesis and processing for use in designing and fabricating novel tissue engineered constructs. The unifying theme is to use micron and sub-micron fabrication strategies to form advanced tissue engineering scaffolds which are able to precisely control the microenvironment of cells. These efforts are organized into two thrusts; (1) materials synthesis and process development for microfluidic scaffold fabrication and (2) micro- and nanofabricated synthetic substratum for controlling cell function. In the first thrust, materials-specific processes for the fabrication of poly(glycerol-co-sebacate), a synthetic elastomeric biodegradable polyester, into three-dimensional, hepatocyte-seeded microfluidic constructs is discussed. Material advantages of natural proteins motivated the fabrication of next-generation microfluidic scaffolds using silk fibroin from the Bombyx mori as a bulk material. The need to combine the advantages of both natural proteins and synthetic polyesters motivated the synthesis and characterization of a new class of biodegradable elastomers termed poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate) (APS). APS polymers are tunable and possess the advantages of both natural and synthetic polymers. APS polymers induce a favorable biomaterial-tissue response including reduced fibrous capsule formation and macrophage recruitment compared to PLGA. In vivo degradation half lives could be controlled to between approximately 6 and 100 wks by adjusting polymer composition and processing. The second thrust focuses on the interaction with cells and synthetically fabricated nanotopographic substrates for potential in vascularized tissue engineering applications.; (cont.) The contact guidance response of human embryonic stem cells to poly(dimethylsiloxane) (PDMS) substrates with 600 nm ridge-groove geometry and 600 ± 150 nm feature height was characterized. This motivated the study of endothelial progenitor cell function and morphology on nanofabricated PDMS substrates. Endothelial progenitor cells (EPCs) were found to exhibit increased doubling time from 16.2 ± 0.8 to 20.9 ± 1.9 h for cells grown on flat and nanotopographic substrates...

Hydrogel cell encapsulation for tissue engineering

Ling, Yibo
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 124 leaves
ENG
Relevância na Pesquisa
66.11%
The engineering of artificial tissues for restoration or replacement of organ function holds the potential to alter the landscape of medical therapeutics. In many tissue engineering approaches, cells seeded within 3D porous structures are expected to remodel into tissue-like structures. Despite significant progress, difficulties in lack of control over tissue architecture as well as vascularization continue to limit the efficacy of engineered constructs. This thesis describes work aimed at tackling these two problems. First, two techniques for generating size- and shape-controlled cell-laden hydrogels are described in the context of potential modular assembly for conferring greater control over the geometry of homotypic and heterotypic cell arrangements within engineered tissues. Then, a method for producing cell-loaded microfluidic agarose hydrogels for tissue engineering is described.; by Yibo Ling.; Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.; Vita.; Includes bibliographical references (leaves 116-123).

Regional Characterization of the Knee Meniscus and Tissue Engineering with Dermal Stem Cells

Sanchez-Adams, Johannah
Fonte: Universidade Rice Publicador: Universidade Rice
ENG
Relevância na Pesquisa
66.22%
Towards understanding regional meniscus characteristics important for tissue engineering efforts, meniscus cells were characterized biomechanically and an effective method for isolating these cells for tissue engineering was determined. It was found that the meniscus contains cells that are biomechanically distinct, with outer meniscus cells showing higher stiffness than inner cells. It was also determined that meniscus cells as a whole were more biomechanically similar to ligament cells than to articular chondrocytes, indicating that tissue properties may correlate with cellular mechanics. In addition to showing regionally distinct biomechanical properties, enzymatic isolation of meniscus cells was found to cause varying phenotypic changes in cells from the inner, middle, and outer regions. A comparison of isolation techniques also indicated that sequential digestion of meniscus tissue with pronase and collagenase was able to yield more cells with higher viability than other techniques tested, and those isolated cells created stiffer and more glycosaminoglycan (GAG) rich constructs when used in a tissue engineering modality than cells isolated using only collagenase. The identification of an effective mode of isolating meniscus cells is of great use to tissue engineering efforts...

Investigation of surface mechanical environment as an optimization criterion for improved tissue engineering scaffolds

Bucklen, Brandon
Fonte: Universidade Rice Publicador: Universidade Rice
ENG
Relevância na Pesquisa
66.13%
Trabecular bone, the porous bone found predominately in the spine and ends of long bones, is a mechanically regulated tissue. The hierarchy of bone consists of several levels of structure such as raw collagen and calcium phosphate on the microscale to trabecular packets, which are constantly being remodeled by bone cells on the tissue level. The remodeling of bone is believed to be explained through the concept of functional adaptation-where bone is a maximum strength yet minimum weight material. In functional adaptation, phenomenological models are able to predict the density distributions and bone shapes that are witnessed in vivo to a certain degree. Functional adaptation assumes there is an equilibrium state in which no changes in bone mass or structure will occur at the bony surface. Topological and mass changes are incurred on a local level when equilibrium is not achieved. The combination of these local changes produces a self-organized structure -meaning that the global bone shape is explained by simple local rules. Unfortunately, neither tissue engineering nor medical device design has incorporated the knowledge base of functional adaptation of bone into their orthopedic designs. The objective of this dissertation work was to examine how the concept of functional adaptation could be applied to tissue engineering of bone in so much as it leads to the development of a computer-aided tissue engineering (CA TE) framework. The idea was to increase the specificity in which implant/scaffold architectural shape can be matched to tissue mechanical properties of the spine (or other locations)...

Matrix-Derived Microcarriers for Adipose Tissue Engineering

TURNER, ALLISON EUGENIA BOGART
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
66.15%
In vivo, adipose tissue demonstrates only a limited capacity for self-repair, and the long-term treatment of subcutaneous defects remains an unresolved clinical problem. With the goal of regenerating healthy tissues, many tissue-engineering strategies have pointed to the potential of implementing three-dimensional (3-D), cell-seeded scaffolds for soft tissue augmentation and wound healing. In particular, microcarriers have shown promise as both cell expansion substrates and injectable cell-delivery vehicles for these applications. However, limited research has investigated the engineering of tissue-specific microcarriers, designed to closely mimic the native extracellular matrix (ECM) composition. In this work, methods were developed to fabricate microcarriers from decellularized adipose tissue (DAT) via non-cytotoxic protocols. Characterization by microscopy confirmed the efficacy of the fabrication protocols in producing stable beads, as well as the production of a microporous surface topography. The mean bead diameter was 934 ± 51 μm, while the porosity was measured to be 29 ± 4 % using liquid displacement. Stability and swelling behavior over 4 weeks indicated that the DAT-based microcarriers were effectively stabilized with the non-cytotoxic photochemical crosslinking agent rose bengal...

Produção e caracterização de arcabouços porosos de compósitos hidroxiapatita-titânia (HA-TiO2) para uso em engenharia tecidual óssea; Production and characterization of hydroxyapatite-titanium oxide scaffolds for bone tissue engineering

André Gustavo de Sousa Galdino
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 24/05/2011 PT
Relevância na Pesquisa
66.11%
À medida que há uma melhoria na tecnologia aplicada à saúde humana, a expectativa de vida vem aumentando, mas nem todas as partes do corpo podem manter suas funções com o processo de envelhecimento. É preciso que os ossos e a cartilagem apóiem o envelhecimento do corpo, embora as células que os produzem se tornem menos ativas com o tempo. Outros órgãos, tais como os rins, o coração e o fígado devem ser operados para ter um tempo de vida maior. A engenharia tecidual foi desenvolvida para substituir, reparar ou reconstruir tecidos ou órgãos perdidos ou danificados por acidentes ou doenças graves através da utilização e desenvolvimento de novos materiais, que sejam biocompatíveis, bioabsorvíveis, porosos, entre outras características. Os scaffolds são arcabouços tridimensionais porosos e são utilizados na regeneração de tecidos para seu estado natural e suas funções, que é fundamental para a engenharia tecidual. Eles podem ser classificados em arcabouços que induzem a migração e o crescimento celular e em arcabouços carreadores de células osteogênicas autógenas, que foram colonizadas em biorreatores e subsequentemente reimplantadas no paciente. Tais scaffolds podem ser naturais ou sintéticos. O objetivo deste trabalho é avaliar o compósito poroso de hidroxiapatita - titânia (HATiO2)...

Tissue Engineering of a Differentiated Skeletal Muscle Construct with Controllable Structure and Function

Bian, Weining
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2011
Relevância na Pesquisa
66.14%

Transplantation of a functional engineered skeletal muscle substitute is a promising therapeutic option to repair irreversible muscle damage, and, on the other hand, functional muscle tissue constructs can serve as in vitro 3D tissue models that complement the conventional 2D cell cultures and animal models to advance our limited understanding of intrinsic myogenesis and muscle regeneration process. However, the engineering of skeletal muscle constructs with comparable contractile function to the native muscle is hampered by the lack of 1) effective and reproducible methods to form relatively large muscle constructs composed of viable, dense, aligned and matured myofibers, and 2) beneficial microenvironmental cues as well as physiological stimulations that favor the growth, differentiation and maturation of myogenic cells. Thus, in this thesis, I have developed a mesoscopic hydrogel molding approach to fabricate relatively large engineered muscle tissue networks with controllable thickness, pore dimensions, overall myofiber alignment and regional myofiber orientation. I then investigated the effect of variation in pore length on the force generation and passive properties of engineered muscle networks and the potential to improve the contractile function of engineered muscle networks with the treatment of a soluble neurotrophic factor...

Resilin-like polypeptide-poly(ethylene gylcol) hybrid hydrogels for mechanically-demanding tissue engineering applications

McGann, Christopher Leland
Fonte: University of Delaware Publicador: University of Delaware
Tipo: Tese de Doutorado
Relevância na Pesquisa
66.13%
Kiick, Kristi L.; Technological progress in the life sciences and engineering has combined with important insights in the fields of biology and material science to make possible the development of biological substitutes which aim to restore function to damaged tissue. Numerous biomimetic hydrogels have been developed with the purpose of harnessing the regenerative capacity of cells and tissue through the rational deployment of biological signals. Aided by recombinant DNA technology and protein engineering methods, a new class of hydrogel precursor, the biosynthetic protein polymer, has demonstrated great promise towards the development of highly functional tissue engineering materials. In particular, protein polymers based upon resilin, a natural protein elastomer, have demonstrated outstanding mechanical properties that would have great value in soft tissue applications. This dissertation introduces hybrid hydrogels composed of recombinant resilin-like polypeptides (RLPs) cross-linked with multi-arm PEG macromers. Two different chemical strategies were employed to form RLP-PEG hydrogels: one utilized a Michael-type addition reaction between the thiols of cysteine residues present within the RLP and vinyl sulfone moieties functionalized on a multi-arm PEG macromer; the second system cross-links a norbornene-functionalized RLP with a thiol-functionalized multi-arm PEG macromer via a photoinitiated thiol-ene step polymerization. Oscillatory rheology and tensile testing confirmed the formation of elastic...

In vitro evaluation of Malaysian Natural coral Porites bone graft substitutes (CORAGRAF) for bone tissue engineering: a preliminary study; In vitro evaluation of Malaysian Natural coral Porites bone graft substitutes (CORAGRAF) for bone tissue engineering: a preliminary study

AL-Salihi, K. A.
Fonte: UNICAMP/FOP Publicador: UNICAMP/FOP
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 02/12/2015 ENG
Relevância na Pesquisa
66.14%
Aim: An approach for three-dimensional (3D) bone tissue generation from bone marrow mesenchymal adult stem cells (BMSC-AS) was investigated. Methods: The BMSC-AS cells were induced to differentiate into osteogenic precursors, capable of proliferating, and subsequently differentiating into bone-forming cells. The differentiated cells were seeded on the surface of coral discs with a mean diameter 10 (±2) mm and a mean thickness 1 (±0.5) mm. The seeded scaffolds were characterized using von Kossa and Alizarin Red staining, electron and confocal microscopy and RT-PCR analysis. Results: The results demonstrated that BMSC-AS derived bone-forming cells attached to and colonized into coral scaffolds. Furthermore, these cells produced bone nodules when grown for 3-4 weeks in mineralization medium containing ascorbic acid and beta-glycerophosphate both in tissue culture plates and in scaffolds. The differentiated cells also expressed osteospecific markers when grown both in the culture plates and in 3D scaffolds. Osteogenic cells expressed alkaline phosphatase, osteocalcin, and osteopontin, but not a BMSC-AS cell-specific marker, oct-4. Conclusion: These findings suggest that Malaysian Natural coral Porites bone graft substitutes (CORAGRAF) with BMSC-AS cells can be used for in vitro tissue engineering to cultivation of graftable skeletal structures.; Aim: An approach for three-dimensional (3D) bone tissue generation from bone marrow mesenchymal adult stem cells (BMSC-AS) was investigated. Methods: The BMSC-AS cells were induced to differentiate into osteogenic precursors...