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Tratamento de defeitos ósseos cervicais com materiais osseocondutores porosos imediatamente à instalação de implantes: estudo histológico, histométrico, micro-tomográfico e de análise de frequência de ressonância em cães; Treatment of cervical bone defects with porous osteoconductive materials in immediate implants: a histological, histometric, micro-CT and RFA study in dogs

Antunes, Antonio Azoubel
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/09/2013 PT
Relevância na Pesquisa
27.12%
O objetivo do presente estudo foi comparar a eficácia da implantação de biomateriais porosos na neoformação óssea e reparo de defeitos cervicais mandibulares em cães, com ou sem a técnica de regeneração óssea guiada (ROG). Bio-Oss Block® (BB), Bio-Oss Collagen® (BC), Bio-Oss® em grânulos (BG), osso autógeno (Ab) e coágulo (Cg) foram utilizados nas mesmas situações experimentais. Para o grupo com membrana foi utilizado o BioGide®. Doze cães foram submetidos a extrações dos pré-molares e primeiros molares mandibulares bilateralmente. Quatro meses após cinco defeitos ósseos (6 mm de diâmetro/4 mm de profundidade) foram confeccionados em um lado. Implantes de 3,3 x 10 mm foram instalados na mesial de cada defeito, proporcionando um "gap" distal de 2,7 mm. Os defeitos foram aleatoriamente preenchidos com Ab, Cg, BB, BC e BG. Os mesmos procedimentos foram executados no lado oposto após oito semanas. A membrana foi utilizada para recobrir os defeitos em metade dos lados. Os animais foram sacrificados após oito semanas. A estabilidade dos implantes foi aferida pelo Osstell Mentor®, na instalação do implante e no sacrifício. Os espécimes (n=60, sendo 3 de cada grupo) foram escaneados em micro-tomógrafo Skyscan® 1172. Após aquisição das imagens...

Bioética e biossegurança : uso de biomateriais na prática odontológica; Bioethics and biosafety: the use of biomaterials in dental practice

Bugarin Júnior, João Geraldo; Garrafa, Volnei
Fonte: Faculdade de Saúde Pública de da Universidade de São Paulo Publicador: Faculdade de Saúde Pública de da Universidade de São Paulo
Tipo: Artigo de Revista Científica
POR; ENG
Relevância na Pesquisa
27.09%
OBJETIVO: Analisar o uso de biomateriais em odontologia por cirurgiões dentistas especialistas sob os aspectos da Teoria Bioética do Princiapialismo e da Ética da Responsabilidade individual e Coletiva. MÉTODOS: Foram aplicados questionários a 95 cirurgiões dentistas registrados no Conselho Regional de Odontologia do Distrito Federal, 2002. sobre o uso de biomateriais em sua prática. Dados relativos ao controle sanitário foram obtidos por meio das respostas desses cirurgiões dentistas e de pesquisa nos órgãos competentes. RESULTADOS: Os profi ssionais entrevistados utilizavam rotineiramente biomateriais, sendo que 45% relataram acreditar não haver riscos para os pacientes; 48% não consideram biomaterial como medicamento e 70% se sentiam seguros com relação à origem, apesar de membranas e osso serem os itens mais adquiridos por meio de vendedores autônomos. Apesar disso, 96% dos entrevistados afirmaram que deveria haver maior controle das autoridades sanitárias. Mais da metade dos entrevistados (51%) referiu pouca ou nenhuma participação do paciente no processo de escolha terapêutica. O termo de consentimento informado foi anexado por 12% dos cirurgiões dentistas pesquisados. CONCLUSÕES: Os resultados mostraram que os profi ssionais utilizam biomateriais desconhecendo riscos e efeitos adversos...

Preparation and characterization of ethanol-treated silk fibroin dense membranes for biomaterials application using waste silk fibers as raw material

NOGUEIRA, Grinia M.; RODAS, Andrea C. D.; LEITE, Carlos A. P.; GILES, Carlos; HIGA, Olga Z.; POLAKIEWICZ, Bronislaw; BEPPU, Marisa M.
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.74%
The possibility of producing valued devices from low cost natural resources is a subject of broad interest. The present study explores the preparation and characterization of silk fibroin dense membranes using waste silk fibers from textile processing. Morphology, crystallinity, thermal resistance and cytotoxicity of membranes as well as the changes on the secondary structure of silk fibroin were analyzed after undergoing treatment with ethanol. Membranes presented amorphous patterns as determined via X-ray diffraction. The secondary structure of silk fibroin on dense membranes was either random coil (silk I) or p-sheet (silk II), before and after ethanol treatment, respectively. The sterilized membranes presented no cytotoxicity to endothelial cells during in vitro assays. This fact stresses the material potential to be used in the fabrication of biomaterials, as coatings of cardiovascular devices and as membranes for wound dressing or drug delivery systems. (C) 2010 Elsevier Ltd. All rights reserved.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Electrochemical behavior of two austenitic stainless steel biomaterials

GIORDANO, Enrico J.; ALONSO-FALLEIROS, Neusa; FERREIRA, Itamar; BALANCIN, Oscar
Fonte: Escola de Minas Publicador: Escola de Minas
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.74%
O presente trabalho avaliou a resistência à corrosão localizada de dois aços inoxidáveis austeníticos utilizados na fabricação de implantes ortopédicos: o aço ASTM F138, material metálico atualmente mais utilizado em aplicações ortopédicas e o aço ISO 5832-9, aço com adição de nióbio e nitrogênio e que vem sendo apontado como uma alternativa para a substituição do aço F138, para aplicações mais severas de carregamento e tempo de permanência no interior do corpo humano. Ensaios de polarização mostraram que o aço ISO 5832-9 apresenta resistência à corrosão localizada muito superior à do aço F138. O potencial crítico de pite do aço ISO 5832-9 não foi observado na curva de polarização cíclica até o potencial de transpassivação do material. O ensaio potenciostático de corrosão por risco confirmou a superioridade do aço ISO 5832-9. Observou-se a reconstituição do filme passivo danificado mecanicamente, mesmo em potenciais tão elevados como 800 mV SCE. Análises por microscopia eletrônica de varredura confirmaram a presença de pites de corrosão de crescimento estável, na superfície da amostra de aço F 138, e a ausência desses pites, na amostra do aço ISO 5832-9. A maior resistência à corrosão localizada do aço ISO 5832-9 é...

Biofunctionality and immunocompatibility of starch-based biomaterials

Marques, A. P.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Tese de Doutorado
Publicado em //2004 ENG
Relevância na Pesquisa
27.16%
A procura de novos biomateriais que desempenhem funções específicas sem, no entanto, desencadearem respostas negativas nos hospedeiros constitui um desafio permanente e actual nesta área. Biomateriais degradáveis foram uma das soluções propostas e actualmente em aplicação mas, embora possuam vantagens inegáveis, também apresentam alguns problemas nomeadamente no que diz respeito aos seus produtos de degradação e respectivos efeitos negativos consequentes. Outros biomateriais, entre os quais polímeros de origem natural, foram propostos considerando que os seus produtos de degradação poderão ser incorporados nas vias metabólicas normais evitando efeitos secundários no hospedeiro. Até ao momento, e apesar de todos os esforços e do grande número de dispositivos biomédicos desenvolvidos, o biomaterial ideal para uma aplicação específica ainda não foi encontrado. Estudos com polímeros biodegradáveis à base de amido demonstraram que estes materiais possuem propriedades promissoras abrindo novas perspectivas para a sua possível aplicação numa variedade de aplicações biomédicas. Assim, de modo a demonstrar que estes materiais têm de facto potencial para serem utilizados em, por exemplo, substituição óssea...

In vivo assessment of the host reactions to natural origin biomaterials aimed to be used as wound dressers and as bone tissue engineering scaffolds

Santos, T. C.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Tese de Doutorado
Publicado em 11/01/2010 ENG
Relevância na Pesquisa
27.09%
Tese de doutoramento em Ciência e Tecnologia de Materiais (ramo de conhecimento em Engenharia de Tecidos - Materiais Híbridos); The development, in recent years, of novel biomaterials for tissue engineering (TE) and regenerative medicine, is an attempt to give an answer to the rising needs of the new tissue replacement/regeneration strategies. However, the increasing complexity of TE devices, comprising cells and/or bioactive agents within 3D scaffolding structures, implies additional concerns regarding adverse host reactions to the implantable constructs. Despite all the investment in the research on stem cells technology, as well as in the identification of key mediators in inflammation/immune reaction and differentiation pathways, the role of support biomaterials in the host reaction has been somewhat neglected. Natural-origin biomaterials have been considered for many years as a way to improve, in comparison to synthetic polymers, in vivo biofunctionality and to modulate/avoid a harmful host response due to its similarities with biological molecules. This PhD work attempted to gather deeper knowledge on the host reactions elicited by natural-origin biomaterials processed under different conditions and aimed at skin wound dressing and bone TE applications. In a first approach...

Micro/nano-scale strategies for engineering in vitro the celular microenvironment using biodegradable biomaterials

Coutinho, Daniela F.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Tese de Doutorado
Publicado em 05/12/2011 ENG
Relevância na Pesquisa
27.09%
Programa doutoral em Bioengenharia; Biological tissues result of a specific spatial organization of cells, extracellular matrix (ECM) molecules, and soluble factors. These micro and nanoscaled biological entities organize into regional tissue architectures, creating highly complex and heterogeneous cellular microenvironments. To generate functional tissue equivalents in vitro, engineered biomaterials should mimic the structural, chemical and cellular complexity by recapitulating the unique native microenvironments. Thus, the main goal of this thesis was to engineer biodegradable polymers using various micro and nanofabrication techniques, with specific structural, biochemical and cellular cues for improved performance. The main governing hypotheses of this thesis were: 1) substrates with improved structural properties can be engineered using biodegradable polymers that have previously shown good results in in vivo studies, 2) biochemical cues can be incorporated into biodegradable polymers, yielding biomaterials with integrated chemical cues for improved cellular performance, and 3) these structural and biochemical cues can be incorporated into a single system. To develop biomaterials with structural cues, micromolding of poly(butylene succinate) (PBS) was performed to engineer surfaces with features at a microscale that induced the alignment of human adipose stem cells. Although this polymeric material has been processed at a macroscale into scaffolds...

Editorial [a] Materials for Healthcare Applications Symposium, EUROMAT 2011 (Montpellier, France, 12–15 September 2011)

Boccaccini, A. R.; Mano, J. F.; Campo, Aranzazu del; Verné, Enrica
Fonte: IOP publishing Ltd. Publicador: IOP publishing Ltd.
Tipo: Outros
Publicado em /09/2012 ENG
Relevância na Pesquisa
27.16%
The advancement of the healthcare and biomedical sectors requires the improvement of traditional biomaterials and the development of new and multifunctional biomaterial combinations with enhanced structural and biological performance. The need for biomaterials to help tackle the health problems of an increasing elderly population is continuously growing. Biomaterials science and technology is highly interdisciplinary, which involves not only the established materials science disciplines but also scientific fields such as chemistry, biology, bioengineering and medicine. The increasing impact of nanotechnology in the medical field must also be noted as this implies the development of biomimetic surfaces, nanostructured biomaterials and miniaturized devices. At the last European Congress and Exhibition on Advanced Materials and Processes (EUROMAT 2011: http://euromat2011.fems.eu) held in Montpellier, France in September of last year, the topic of materials for healthcare was covered in three focused symposia, namely: i) bioactive coatings and material-tissue interfaces, ii) smart and biomimetic materials for biomedical applications and tissue engineering and iii) mechanical characterization and modeling of tissues and biomedical materials at all length scales. The oral and poster presentations reflected novel research on biomaterials covering new areas of processing...

Abdominal wall healing in incisional hernia using different biomaterials in rabbits

Aramayo,Ana Letícia Gomes; Lopes Filho,Gaspar de Jesus; Barbosa,Cirênio de Almeida; Amaral,Vânia da Fonseca; Costa,Luciano Assis
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2013 EN
Relevância na Pesquisa
36.74%
PURPOSE: To investigate abdominal wound healing using specific biomaterials in incisional hernias. METHODS: Incisional hernias were produced in 40 rabbits, after that they were reoperated with or without the use of meshes: PREMILENE® (PPL), ULTRAPRO® (UP), PROCEED® (PCD) or repairing without mesh (TRANSPALB). After 30 days a macroscopic and microscopic study of the part withdrawn from the abdominal wall was performed. RESULTS: Macroscopic: adhesion Area: PPL> UP and PCD (p = 0.031). Vascularization: PPL> UP and PCD (p = 0.001). PPL groups (p = 0.032) and PCD (p <0.001) showed greater meshes shrinkages when compared to UP. Microscopic: neutrophils: PCD> PPL, UP and TRANSPALB (p = 0.010); eosinophils: PPL> UP, and TRANSPALB PCD (p = 0.010); granulation tissue: PPL and PCD> UP and TRANSPALB (p <0.001); macrophages : PPL, UP and PCD> TRANSPALB (p <0.001); lymphocytes: PPL and PCD> UP (p = 0.009) and TRANSPALB (p <0.001); giant cells: PPL, UP and PCD> TRANSPALB (p <0.001); viscera adhered: PPL and UP> PCD and TRANSPALB (p <0.001). CONCLUSION: All types of meshes caused the formation of adhesions. The UP and PCD groups showed lower area and vascularization of the adhesions. The PPL and PCD groups showed higher meshes shrinkage and there was a predominance of acute inflammatory process in the PCD group.

Polysaccharide-based biomaterials with antimicrobial and antioxidant properties

Coma,Véronique
Fonte: Associação Brasileira de Polímeros Publicador: Associação Brasileira de Polímeros
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
36.74%
Active packaging is one of the responses to the recent food-borne microbial outbreaks and to the consumer’s demand for high quality food and for packaging that is more advanced and creative than what is currently offered. Moreover, with the recent increase in ecological awareness associated with the dramatic decrease in fossil resources, research has turned towards the elaboration of more natural materials. This paper provides a short review of biomaterials exhibiting antimicrobial and antioxidant properties for applications in food preservation. The two main concepts of active biopackaging materials are briefly introduced. The different polysaccharides potentially used in packaging materials are then presented associated with a brief overview of research works related to biopackaging, exhibiting notably antimicrobial or antioxidant properties. Finally, future trends such as the release-on-demand of bioactive agents are discussed.

Electrochemical behavior of two austenitic stainless steel biomaterials

Giordano,Enrico J.; Alonso-Falleiros,Neusa; Ferreira,Itamar; Balancin,Oscar
Fonte: Escola de Minas Publicador: Escola de Minas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2010 EN
Relevância na Pesquisa
36.74%
Potentiodynamic and potentiostatic polarization measurements were conducted in 0.9% NaCl solution to investigate the localized corrosion susceptibility of two austenitic stainless steel biomaterials: a low nitrogen, according to ASTM F 138 - the metallic material most widely utilized today in orthopedic applications; and a nitrogen- and niobium-bearing stainless steel, according to ISO 5832-9, which has shown a promising potential as a substitute of the F 138 steel for more severe loading applications and longer times inside the human body. The polarization tests revealed that the ISO 5832-9 steel is more corrosion resistant than the F 138. The critical pitting potential of the ISO 5832-9 steel could not be observed in the cyclic polarization curve up to the value of potential corresponding to its transpassivity. The potentiostatic scratch test confirmed the superiority of the ISO 5832-9 steel, which heal the mechanically damaged passive film at applied potential as high as 800 mV (SCE). Scanning electron microscopy (SEM) examination confirmed the presence of corrosion pits - lacelike pits - in a stable growth stage on the surface of F 138 steel and the absence of such pits in the specimens of the ISO 5832-9 steel. The higher corrosion resistance of the latter is attributed to the increased stability of the passive film and the high tendency to repassivate...

A new approach to the rationale discovery of polymeric biomaterials

Kohn, Joachim; Welsh, William J.; Knight, Doyle
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.12%
This paper attempts to illustrate both the need for new approaches to biomaterials discovery as well as the significant promise inherent in the use of combinatorial and computational design strategies. The key observation of this Leading Opinion Paper is that the biomaterials community has been slow to embrace advanced biomaterials discovery tools such as combinatorial methods, high throughput experimentation, and computational modeling in spite of the significant promise shown by these discovery tools in materials science, medicinal chemistry and the pharmaceutical industry. It seems that the complexity of living cells and their interactions with biomaterials has been a conceptual as well as a practical barrier to the use of advanced discovery tools in biomaterials science. However, with the continued increase in computer power, the goal of predicting the biological response of cells in contact with biomaterials surfaces is within reach. Once combinatorial synthesis, high throughput experimentation, and computational modeling are integrated into the biomaterials discovery process, a significant acceleration is possible in the pace of development of improved medical implants, tissue regeneration scaffolds, and gene/drug delivery systems.

Current requirements for polymeric biomaterials in otolaryngology

Sternberg, Katrin
Fonte: German Medical Science GMS Publishing House Publicador: German Medical Science GMS Publishing House
Tipo: Artigo de Revista Científica
Publicado em 10/03/2011 EN
Relevância na Pesquisa
27.16%
In recent years otolaryngology was strongly influenced by newly developed implants which are based on both, innovative biomaterials and novel implant technologies. Since the biomaterials are integrated into biological systems they have to fulfill all technical requirements and accommodate biological interactions. Technical functionality relating to implant specific mechanical properties, a sufficiently high stability in terms of physiological conditions, and good biocompatibility are the demands with regard to suitability of biomaterials. The goal in applying biomaterials for implants is to maintain biofunctionality over extended periods of time. These general demands to biomaterials are equally valid for use in otolaryngology. Different classes of materials can be utilized as biomaterials. Metals belong to the oldest biomaterials. In addition, alloys, ceramics, inorganic glasses and composites have been tested successfully. Furthermore, natural and synthetic polymers are widely used materials, which will be in the focus of the current article with regard to their properties and usage as cochlear implants, osteosynthesis implants, stents, and matrices for tissue engineering. Due to their application as permanent or temporary implants materials are differentiated into biostable and biodegradable polymers. The here identified general and up to date requirements for biomaterials and the illustrated applications in otolaryngology emphasize ongoing research efforts in this area and at the same time demonstrate the high significance of interdisciplinary cooperation between natural sciences...

Surface modification of biomaterials using plasma immersion ion implantation and deposition

Lu, Tao; Qiao, Yuqin; Liu, Xuanyong
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.09%
Although remarkable progress has been made on biomaterial research, the ideal biomaterial that satisfies all the technical requirements and biological functions is not available up to now. Surface modification seems to be a more economic and efficient way to adjust existing conventional biomaterials to meet the current and ever-evolving clinical needs. From an industrial perspective, plasma immersion ion implantation and deposition (PIII&D) is an attractive method for biomaterials owing to its capability of treating objects with irregular shapes, as well as the control of coating composition. It is well acknowledged that the physico-chemical characteristics of biomaterials are the decisive factors greatly affecting the biological responses of biomaterials including bioactivity, haemocompatibility and antibacterial activity. Here, we mainly review the recent advances in surface modification of biomaterials via PIII&D technology, especially titanium alloys and polymers used for orthopaedic, dental and cardiovascular implants. Moreover, the variations of biological performances depending on the physico-chemical properties of modified biomaterials will be discussed.

Integrated Micro/nanoengineered Functional Biomaterials for Cell Mechanics and Mechanobiology: A Materials Perspective

Shao, Yue; Fu, Jianping
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.12%
The rapid development of micro/nanoengineered functional biomaterials in the last two decades has empowered materials scientists and bioengineers to precisely control different aspects of the in vitro cell microenvironment. Following a philosophy of reductionism, many studies using synthetic functional biomaterials have revealed instructive roles of individual extracellular biophysical and biochemical cues in regulating cellular behaviors. Development of integrated micro/nanoengineered functional biomaterials to study complex and emergent biological phenomena has also thrived rapidly in recent years, revealing adaptive and integrated cellular behaviors closely relevant to human physiological and pathological conditions. Working at the interface between materials science and engineering, biology, and medicine, we are now at the beginning of a great exploration using micro/nanoengineered functional biomaterials for both fundamental biology study and clinical and biomedical applications such as regenerative medicine and drug screening. In this review, we present an overview of state of the art micro/nanoengineered functional biomaterials that can control precisely individual aspects of cell-microenvironment interactions and highlight them as well-controlled platforms for mechanistic studies of mechano-sensitive and -responsive cellular behaviors and integrative biology research. We also discuss the recent exciting trend where micro/nanoengineered biomaterials are integrated into miniaturized biological and biomimetic systems for dynamic multiparametric microenvironmental control of emergent and integrated cellular behaviors. The impact of integrated micro/nanoengineered functional biomaterials for future in vitro studies of regenerative medicine...

Evaluation of Silk Biomaterials in Combination with Extracellular Matrix Coatings for Bladder Tissue Engineering with Primary and Pluripotent Cells

Franck, Debra; Gil, Eun Seok; Adam, Rosalyn Mare; Kaplan, David L.; Chung, Yeun Goo; Estrada, Carlos R.; Mauney, Joshua Robert
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.74%
Silk-based biomaterials in combination with extracellular matrix (ECM) coatings were assessed as templates for cell-seeded bladder tissue engineering approaches. Two structurally diverse groups of silk scaffolds were produced by a gel spinning process and consisted of either smooth, compact multi-laminates (Group 1) or rough, porous lamellar-like sheets (Group 2). Scaffolds alone or coated with collagen types I or IV or fibronectin were assessed independently for their ability to support attachment, proliferation, and differentiation of primary cell lines including human bladder smooth muscle cells (SMC) and urothelial cells as well as pluripotent cell populations, such as murine embryonic stem cells (ESC) and induced pluripotent stem (iPS) cells. AlamarBlue evaluations revealed that fibronectin-coated Group 2 scaffolds promoted the highest degree of primary SMC and urothelial cell attachment in comparison to uncoated Group 2 controls and all Group 1 scaffold variants. Real time RT-PCR and immunohistochemical (IHC) analyses demonstrated that both fibronectin-coated silk groups were permissive for SMC contractile differentiation as determined by significant upregulation of α-actin and SM22α mRNA and protein expression levels following TGFβ1 stimulation. Prominent expression of epithelial differentiation markers...

BIOMATERIAIS: TIPOS, APLICAÇÕES E MERCADO

Pires,Ana Luiza R.; Bierhalz,Andréa C. K.; Moraes,Ângela M.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2015 PT
Relevância na Pesquisa
27.12%
AbstractThe types of compounds used in the production of biomaterials, namely metals, ceramics, synthetic and natural polymers, as well as composite materials, are discussed in the present work, together with details of their application and evolution from biocompatible to bioactive, biodegradable, and biomimetic clinical products. The chemical structure, the three-dimensional structure, and the molecular organization of compounds frequently used in the manufacture of relevant classes of biomaterials are discussed, along with their advantages and some of their major limitations in specific clinical applications. The main chemical, physical, mechanical, and biological requirements of biomaterials categories are presented, as well as typical tissular responses to implanted biomaterials. Reasons for the recent economic growth of the biomaterials market segment are addressed, and the most successful biomaterial categories are discussed, emphasizing areas such as orthopedic and cardiovascular implants, regenerative medicine, tissue engineering, and controlled drug release devices. Finally, the need for the development of innovative and more accessible biomaterials, due to the expected increase in the number of elderly people and the growing trend of personalized medical procedures...

Efeito da adição de oxigênio na estabilidade e metaestabilidade de fases em ligas Ti-Nb aplicadas como biomaterial; Effect of oxygen additions in the phase stability and metastability of Ti-Nb alloys applied as biomaterials

Manolo Marcial Taquire De la Cruz
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/07/2011 PT
Relevância na Pesquisa
36.74%
Em se tratando de biomateriais ortopédicos, as ligas de titânio tipo ß apresentam diversas vantagens em relação às ligas do tipo 'alfa' + ß. Ligas contendo elementos ß estabilizadores são mais interessantes em função da alta resistência mecânica específica, da elevada resistência à corrosão e da excelente biocompatibilidade. Em adição, essas ligas exibem baixo módulo de elasticidade, característica fundamental na fabricação de implantes ortopédicos. O objetivo deste trabalho é a avaliação da estabilidade e metaestabilidade de ligas de Ti tipo ß do sistema Ti-Nb com adições de oxigênio. Amostras com composições Ti-30Nb-xO e Ti-35Nb-xO (x =0,1; 0,25; 0,5) (% em peso) foram preparadas por fusão a arco voltaico, homogeneizadas quimicamente em altas temperaturas, forjadas a quente e finalmente, submetidas a diferentes taxas de resfriamento. Tais amostras foram caracterizadas em relação à microestrutura por meio de microscopia óptica e eletrônica de varredura e de difração de raios-X, enquanto o comportamento mecânico foi avaliado por meio de ensaios de dureza Vickers, de medidas de módulo de elasticidade por meio de técnicas acústicas e de nano-dureza usando a técnica de nano-indentação. Os resultados obtidos indicam que baixas taxas de resfriamento conduzem à microestrutura formada pelas fases 'alfa' e ß e eventualmente...

Desenvolvimento e caracterização de compósitos de Poli (E-Caprolactona) PCL e ß-Fosfato Tricálcico (ß-TCP) para uso em biomateriais; Development and characterization of composites Poly(episolon-caprolactone) (PCL) and Beta-Tricalcium Phosphate (TCP) for use in biomaterials

Zenaide Solomão
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/02/2011 PT
Relevância na Pesquisa
36.74%
A utilização de biomateriais para substituir, reparar tecidos e órgãos lesados dos seres humanos tem aumentado muito ultimamente devido a diversos fatores como o crescimento da população e a sua maior expectativa de vida. A engenharia tecidual é um campo interdisciplinar que integra princípios da biologia celular e molecular, química, genética, ciências dos materiais e engenharia biomédica, para produzir compósitos tridimensionais inovativos, capazes de substituir tecidos biológicos. O desenvolvimento de novo biomaterial pode ajudar a solucionar este problema, utilizando o método de evaporação de solvente. Este trabalho teve como objetivos: sintetizar e caracterizar o ß-TCP através do método via seca; desenvolver e caracterizar as membranas de poli ('epsilon'-caprolactona) densas e porosas (scaffolds) utilizando dois solventes; preparar e caracterizar os compósitos densos e porosos PCL/ß-TCP; fazer uma avaliação da biocompatibilidade in vitro desses materiais. As seguintes técnicas de caracterização foram utilizadas: MO, MEV, EDS, DRX, TGA,DSC, ensaios mecânicos de tração, teste de viabilidade celular e atividade de fosfatase alcalina. Foi também analisada a sua degradação hidrolitica em solução tampão fosfato (PBS). Essas técnicas foram adequadas para diferenciar as amostras preparadas com os dois solventes utilizados: clorofórmio e diclorometano. Os ensaios mostraram que o último forneceu amostras mais resistentes mecanicamente...

Biosorption of heavy metals from aqueous solutions using keratin biomaterials

Zhang, Helan
Fonte: [Barcelona] : Universitat Autònoma de Barcelona, Publicador: [Barcelona] : Universitat Autònoma de Barcelona,
Tipo: Tesis i dissertacions electròniques; info:eu-repo/semantics/doctoralThesis; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2014 ENG
Relevância na Pesquisa
27.34%
La biosorció és una tècnica eficaç per a l'eliminació de metalls pesants de les aigües residuals resultants de l'activitat humana, principalment de les activitats industrials actuals. Els biomaterials provinents de residus es consideren alternatives ideals com a nous biosorbentes donada la baixa relació del seu cost amb la seva eficàcia i alta capacitat d'adsorció per a metalls pesants. Una àmplia gamma de biomaterials de baix cost provinents de residus, alguns dels quals provenen de processos d'operacions industrials a gran escala, s'han emprat amb èxit com a biosorbents aplicats a l'eliminació de metalls pesants, principalment d'aigües residuals. Com a tipus abundant de recurs biològic, els biomaterials amb base de queratina s'investiguen actualment per a aquest propòsit. Aquests biomaterials mostren una alta capacitat de biosorció de metalls pesants a causa del seu alt contingut en grups funcionals carboxil, hidroxil, amino, així com grups que contenen sofre. Aquesta tesi té a veure amb l'ús de biomaterials de queratina, especialment cabell humà, pèl de gos, plomes de pollastre i llana desgreixada, com a materials biosorbents emprats per a l'eliminació de metalls pesants de solucions aquoses. En primer lloc...