Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-02-06T17:32:01Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 05 LEANDRO.pdf: 1567255 bytes, checksum: 524598baa8a0da3ae61f6dd0f193fb70 (MD5) / Made available in DSpace on 2017-02-06T17:32:01Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 05 LEANDRO.pdf: 1567255 bytes, checksum: 524598baa8a0da3ae61f6dd0f193fb70 (MD5) Previous issue date: 2012-08-22 / Introdução: A reconstrução do parênquima renal requer, em algumas situações, uma técnica cirúrgica mais complexa e delicada. O trauma renal de alto grau e as nefrectomias parciais para remoção de tumores malignos induzem a uma reconstrução renal de difícil execução e possuem um potencial elevado para causar perda completa do órgão. A utilização de substâncias auxiliares na reconstrução renal, tais como: selantes biológicos e hemostáticos têm fundamental importância para a sua preservação. OBJETIVO: Avaliar o efeito hemostático e selante da esponja do biopolímero da cana-de-açúcar em trauma renal de alto grau induzido em coelhos. MÉTODOS: Foi realizado um estudo experimental, prospectivo e pareado, com vinte e quatro unidades renais de doze coelhos da linhagem California. Após indução de trauma renal bilateral e de alto grau (lesão da via coletora), utilizamos, para a reconstrução e hemostasia do parênquima renal direito, a esponja do biopolímero da cana-de-açúcar, e à esquerda, foi utilizada a esponja de Surgifoam®. Nos dois lados, foi realizada uma sutura com fio de poliglactina 4/0 sobre as esponjas. Desta forma, cada coelho se tornou controle de si mesmo. Durante o procedimento cirúrgico, foram avaliados: o tempo cirúrgico total, o tempo para hemostasia e o grau de perda sanguínea. Os animais foram sacrificados após quatro semanas, sendo os rins retirados e encaminhados para a análise histológica. Foi avaliada a presença de fístulas, urinoma, hematomas e aderências aos órgãos adjacentes no momento da nefrectomia. A análise histológica observou o grau de inflamação e fibrose, assim como presença de necrose. RESULTADOS: Em relação ao tamanho dos rins, não houve diferença estatística entre os grupos (p=0,058), o que configura uma homogeneidade entre eles. Da mesma forma, o tempo para hemostasia foi similar (p=0,195) e a perda sanguínea (p=0,480). Por outro lado, foi notada uma maior incidência de aderências aos órgãos adjacentes no grupo do BCPA, assim como, uma maior intensidade da resposta inflamatória a corpo estranho (p=0,004). Todavia, sem influência nos resultados finais. Não foi evidenciada a ocorrência de hemorragia maciça, formação de hematomas, abscessos, fístulas ou cálculos em nenhuma das unidades renais. A presença de fibrose e necrose foi semelhante nos dois grupos do ponto de vista estatístico (p=0,500 e 0,414, respectivamente). CONCLUSÃO: A esponja do biopolímero da cana-de-açúcar demonstrou eficácia em relação ao controle hemostático e selante sobre o parênquima renal de coelhos, sem causar complicações importantes. Futuros estudos podem direcionar seu uso rotineiro na prática urológica. / Introduction: The reconstruction of the renal parenchyma requires, in some situations, a surgical technique more complex and delicate. The high grade renal trauma and partial nephrectomy for removal of malignant tumors induce a kidney reconstruction difficult to implement and have a high potential to cause complete loss of the organ. The use of auxiliary substances in renal reconstruction, such as biological sealants and hemostatic are of enormous value to their preservation. Objective: To evaluate the effect of sealant and hemostatic sponge biopolymer of sugarcane in high grade renal trauma induced in rabbits. Methods: We conducted an experimental study, prospective, matched, with twenty-four renal units of twelve rabbits from California lineage. After induction of bilateral renal trauma and high-grade lesions, it was used for the reconstruction of right renal parenchymal, the biopolymer sponge of cane sugar, and in left kidney, we used the sponge Surgifoam®. On both sides, we performed a suture with polyglactin 4/0 on the sponges. Thus, each rabbit has control of himself. During surgery, we evaluated the total surgical time, time to hemostasis and the degree of blood loss. The animals were sacrificed after four weeks, and the kidneys removed and sent for histological analysis. We evaluated the presence of fistula, urinoma, hematoma, and adhesions to adjacent organs at the time of nephrectomy. Histological analysis showed the degree of inflammation and fibrosis, as well as necrosis. Results: In relation to the size of the kidneys, there was no statistical difference between groups (p = 0.058), which is one commonality between them. Similarly, time to hemostasis was similar (p = 0.195) and blood loss (p = 0.480). Moreover, it was noted an increased incidence of adhesions to adjacent organs in BCPA group, as well as a greater inflammatory response to foreign bodies (p = 0.004). However, no influence on final results. There was no evidence the occurrence of massive bleeding, hematomas, abscesses, fistulas, or in any calculations of renal units. The presence of fibrosis and necrosis was similar in both groups a statistically (p = 0.500 and 0.414, respectively). Conclusion: The biopolymer sponge of sugarcane has shown efficacy in the hemostatic control and sealant on the renal cortex of rabbits, without causing major complications. Future studies may direct its routine use in urologic practice.

Introduction: The radiopacity is a required property in all dental materials. This characteristic allows this materials be able to be distinguished from the tooth surfaces through the radiography. Portland cement (PC) presents physico-chemical and biological properties similar to mineral trioxide aggregate (MTA), except for radiopacifier. Objective: To evaluate the radiopacity, antimicrobial activity and pH of the MTA, pure PC and PC added different radiopacifiers. Materials and Methods: The radiopacity of MTA, pure PC and PC added the radiopacifying: iodoform, lead oxide, zirconium oxide, bismuth subnitrate, barium sulfate and bismuth oxide in the proportions 15%, 20% and 30% were analyzed. The radiopacity was carried out using a semi-direct digital radiography system (Instrumentarium Kavo EXPRESS®). The PC and cements selected with adequate radiopacity (ANSI/ADA No. 57) were evaluated for their antimicrobial activity and pH. Antimicrobial activity was analyzed by microdilution tests and agar diffusion. The microorganism tested were Enterococcus faecalis, as a standard strain (ATCC 29212) and six clinical strains (LMA 26, LMA 27, LMA 28, LMA 29, LMA 31 and LMA 34). The pH was measured using a digital pH meter (pH Meter Pocket-sized). Statistical analyzes were performed using the Shapiro-Wilk normality test, ANOVA and Tukey with significance level of 5%. Results: Pure PC had the lowest radiopacity. The MTA, PC + iodoform 20% (3.59 mmEq.Al), PC + bismuth oxide 20% (4.79 mmEq.Al), PC + bismuth subnitrate 20% (3.12 mmEq.Al), PC + 20% lead oxide (3.18 mmEq.Al) and PC + 30% zirconium oxide (4.28 mmEq.Al). Regarding the agar diffusion test, the LMA 26 strain was inhibited by PC, PC + Iodoform 20%, PC + 30% Zirconium Oxide, PC + Bismuth subnitrate 20%, and PC + Bismuth Oxide 20%. The LMA 31 strain was inhibited by PC + zirconium oxide 30% and PC + bismuth subnitrate 20% and LMA 27 strain was inhibited by PC + bismuth subnitrate 20%. The other strains were not inhibited. In the microdilution test, most strains was inhibited by tested materials, except the ATCC 29212 strain which was not inhibited by PC + lead oxide 20%. LMA 28 29, 31 and 34 strains were not inhibited by PC + lead oxide 20%and PC + zirconium oxide 30%, in which LMA 28 and 29 strains were not inhibited by PC + bismuth oxide20%. All cements tested showed alkalinity in all experimental periods, in which MTA had the lowest pH. Conclusions: MTA and PC added the radiopacifiers subnitrate bismuth and iodoform in concentrations of 20% by weight, provided satisfactory radiopacity, alkaline medium and promoted bactericidal and bacteriostatic activities against strains of E .faecalis tested. / Introdução: A radiopacidade é uma propriedade obrigatória em todos os materiais odontológicos. Esta característica permite este material seja distinguido das superfícies dentárias através da radiografia. O cimento Portland (CP) apresenta propriedades físicoquímicas e biológicas semelhantes ao Agregado Trióxido Mineral (MTA), exceto pela partícula radiopacificadora. Objetivo: Avaliar a radiopacidade, atividade antimicrobiana e pH do MTA, CP puro e CP adicionado de diferentes radiopacificadores. Materiais e Métodos: Foi analisada a radiopacidade do MTA, CP e CP adicionado dos radiopacificadores: iodofórmio, óxido de chumbo, óxido de zircônio, subnitrato de bismuto, sulfato de bário e óxido de bismuto nas proporções 15%, 20% e 30%. A radiopacidade foi avaliada por meio do sistema de radiografia digital semi-direto (Instrumentarium Kavo EXPRESS®). O CP e os cimentos selecionados com radiopacidade adequada (ANSI/ADA nº 57) foram submetidos à avaliação da atividade antimicrobiana e do pH. A atividade antimicrobiana foi analisada pelos testes de microdiluição e difusão em ágar. O micro-organismo testado foi o Enterococcus faecalis, sendo uma cepa padrão (ATCC 29212) e seis cepas clínicas (LMA 26, LMA 27, LMA 28, LMA 29, LMA 31 e LMA 34). O pH foi aferido com pHmetro digital (pH Meter Pocket-sized). Os testes estatísticos utilizados foram os testes Shapiro-Wilk de normalidade, análise de variância ANOVA e Tukey a nível de significância de 5%. Resultados: O CP puro apresentou o menor valor de radiopacidade, O MTA, CP + iodofórmio 20% (3,59 mmEq.Al), CP + óxido de bismuto 20% (4,79 mmEq.Al), CP + subnitrato de bismuto 20% (3,12 mmEq.Al), CP + óxido de chumbo 20% (3,18 mmEq.Al) e CP + óxido de zircônio 30% (4,28 mmEq.Al). No teste de difusão em ágar, a cepa LMA 26 foi inibida pelo CP, CP + Iodofórmio 20%, CP + Óxido de Zircônio 30%, CP + Subnitrato de Bismuto 20% e CP + Óxido de Bismuto 20%. A cepa LMA 31 foi inibida pelas associações CP + óxido de zircônio 30% e CP + subnitrato de bismuto 20% e a cepa LMA 27 foi inibida pelo CP + subnitrato de bismuto 20%. As demais cepas não foram inibidas. No teste de microdiluição, a maioria das cepas foi inibida pelos materiais-testes, exceto a cepa ATCC 29212 que não foi inibida pelo CP + óxido de chumbo 20%, as cepas LMA 28, 29, 31 e 34 não foram inibidas pelas associações CP + óxido de chumbo 20% e CP + óxido de zircônio 30%, sendo que as cepas LMA 28 e 29 também não foram inibidas pelo CP + óxido de bismuto 20%. Todos os cimentos testados apresentaram alcalinidade em todos os períodos experimentais, sendo que o MTA apresentou os menores valores de pH. Conclusões: O MTA e as concentrações de CP adicionado de 20% do agente radiopacificador subnitrato de bismuto e CP adicionado do agente radiopacificador iodofórmio, 20% em peso, proporcionaram radiopacidade satisfatória, alcalinizaram o meio e promoveram atividades bactericida e bacteriostática contra as cepas de E. faecalis testadas.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-01-06T16:16:41Z No. of bitstreams: 2 Dissertação - Ygor Roberto de Carvalho - 2009.pdf: 1167127 bytes, checksum: 7fe8cf1100e0875c875d048be01ffbbc (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-01-07T08:16:45Z (GMT) No. of bitstreams: 2 Dissertação - Ygor Roberto de Carvalho - 2009.pdf: 1167127 bytes, checksum: 7fe8cf1100e0875c875d048be01ffbbc (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-01-07T08:16:45Z (GMT). No. of bitstreams: 2 Dissertação - Ygor Roberto de Carvalho - 2009.pdf: 1167127 bytes, checksum: 7fe8cf1100e0875c875d048be01ffbbc (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2009-09-28 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Peritoneal adhesions are fibrous bands that form abnormal unions between two or more serosal coating surfaces, may cause obstructions of abdominal tubular organs and pelvic pain. Several studies have been performed using antiinflammatory, anticoagulant, proteolytic agents and biomaterials in the form of film or gel, with the aim of preventing or simply reduce the formation of peritoneal adhesions. The chitosan is a polymer obtained by deacetylation of chitin, a polysaccharide obtained from the exoskeleton of crustaceans and has been used in various medical specialties as a biomaterial. The aim of this study was to evaluate the film based on chitosan as a barrier in the formation of postoperative intestinal adhesions in rabbits. For this, 30 rabbits used were male adult, race New Zealand, with an average weight of three kilograms and clinically healthy, of which 15 were submitted to enterotomy (control group) and 15 to enterotomy with overlap of the chitosan-based film at the intestinal incision (treatment group). Five animals from each group were assessed at seven, 14 and 21 days postoperatively, when held to the macroscopic evaluation of adhesions with regard presence, extent and type, and also performed microscopic evaluation of the enterorrhaphy site and hematimetric exams. The adhesions occurred in 80% of subjects in the control group and 86.7% of treatment group. In the control group 50% of the animals developed adhesions between the site of enterorrhaphy and abdominal wall, while in the treatment group 76.9% of individuals had adhesions between the site of enterorrhaphy and adjacent bowel. The control group had formed adhesions extensions higher than in treatment group. We found statistical differences between subgroups T7 and C7, C14 and T14 on the extent of adhesions (p ≤ 0.05) but not between C21 and T21. Also no significant differences between subgroups on the type of adhesions were seen. As for the histopathological evaluation, there was significant difference (p ≤ 0.05) between the subgroup C7, where 80% of samples the score was considered strong, and T7 in that 80% of the samples was considered moderate score on the concentration of fibroblasts and angiogenesis. Regarding the variable necrosis, was observed in 40% of samples of T7 and 0% of C7 and therefore statistically different (p ≤ 0.05). Significant differences (p ≤ 0.05) were also found between the groups C14 and T14 on variables heterophils (C14, 80% score discreet, T14, 80% score marked), eosinophils (score of 60% in discrete T14, but absent in C14) and necrosis (mild in 60% of C14 and severe in 80% of T14). In subgroups C21 and T21 only the scores of mononuclear cells were statistically different (p ≤ 0.05). The hematimetric variables remained within the normal values for the species. Based on the results we can conclude that the chitosan-based film reduces the extent of intestinal adhesions in rabbits and is useful as a barrier system in this species and that this film, when overlaid with a wound of rabbits induces intestinal tissue response to formation of caseous material. / Aderências abdominais ou peritoniais são faixas fibrosas que formam uniões anormais entre duas ou mais superfícies serosas de revestimento, podendo causar obstruções de órgãos abdominais tubulares e dores pélvicas. Diversos estudos já foram realizados utilizando antiinflamatórios, anticoagulantes, agentes proteolíticos e ainda biomateriais na forma de filme ou gel, com a finalidade de prevenir ou simplesmente reduzir a formação de aderências peritoniais. A quitosana é um polímero obtido pela desacetilação da quitina, que é um polissacarídeo oriundo do exoesqueleto de crustáceos e vem sendo utilizado em diversas especialidades médicas como biomaterial. O objetivo deste estudo foi avaliar o filme à base quitosana como barreira na formação de aderências intestinais pós-operatórias em coelhos. Para isso, utilizou-se 30 leporinos machos, adultos, da raça Nova Zelândia, com peso médio de três quilos e clinicamente sadios, dos quais 15 foram submetidos à enterotomia (grupo controle) e 15 à enterotomia e sobreposição do filme à base de quitosana sobre a incisão cirúrgica intestinal (grupo tratamento). Cinco animais de cada grupo foram avaliados aos sete, 14 e 21 dias pós-operatórios, quando se realizou a avaliação macroscópica das aderências quanto à presença, extensão e o tipo, sendo também realizada avaliação microscópica do sítio da enterorrafia e hematimetria. As aderências ocorreram em 80% dos indivíduos do grupo controle e 86,7% do grupo tratamento. No grupo controle em 50% dos animais as aderências formaram-se entre o sítio da enterorrafia e parede abdominal, enquanto no grupo tratamento 76,9% dos indivíduos apresentaram aderências entre o sítio da enterorrafia e alças intestinais adjacentes. No grupo controle as aderências formadas possuíam extensões maiores que no grupo tratamento. Foram encontradas diferenças estatísticas entre os subgrupos C7 e T7; C14 e T14 quanto à extensão das aderências (p≤ 0,05), mas não entre C21 e T21. Também não foram observadas diferenças significativas entre os subgrupos quanto ao tipo de aderências. Quanto à avaliação histopatológica, houve diferença significativa (p≤ 0,05) entre o subgrupo C7, em que 80% das amostras o escore foi considerado acentuado, e T7 em que 80% das amostras o escore foi considerado moderado quanto à concentração de fibroblastos e angiogênese. Em relação à variável necrose, esta foi observada em 40% das amostras de T7 e 0% de C7 sendo, portanto estatisticamente diferente (p≤ 0,05). Diferenças significativas (p≤ 0,05) também foram encontradas entre os subgrupos C14 e T14 quanto às variáveis heterófilos (C14, 80% escore discreto; T14, 80% escore acentuado), eosinófilos (escore discreto em 60% de T14, porém ausentes em C14) e necrose (discreta em 60% de C14 e acentuada em 80% de T14). Já nos subgrupos C21 e T21 apenas os escores das células mononucleares foram estatisticamente diferentes (p≤ 0,05). As variáveis hematimétricas permaneceram dentro dos valores considerados normais para a espécie. Com base nos resultados pode-se concluir que o filme à base de quitosana reduz a extensão das aderências intestinais em coelhos, sendo útil como sistema de barreira nessa espécie e que este filme, quando sobreposto a uma ferida intestinal de coelhos induz a resposta tissular com formação de material caseoso.

Reembasadores resilientes temporários contendo fármacos antifúngicos foram sugeridos como um tratamento adjunto para estomatite protética. No entanto, antes de utilizar clinicamente estes reembasadores modificados em humanos, é importante avaliar a sua biocompatibilidade em modelos animais. Este estudo avaliou a biocompatibilidade in vivo de um reembasador resiliente temporário para base de prótese (Trusoft) modificado por agentes antimicrobianos em suas mínimas concentrações inibitórias (MCIs) para biofilme de Candida albicans. Dispositivos acrílicos intra-orais (DIOs) foram confeccionados individualmente para 60 ratos Wistar. Os ratos foram divididos em 6 grupos (n=5): 3 grupos controle (Negativo: sem DIO; Geral: DIO sem reembasamento; Positivo: DIO reembasado com Trusoft sem fármacos) e 3 grupos experimentais (DIOs reembasados com Trusoft modificados por fármacos em suas respectivas MCIs: 0,032 g de nistatina, 0,064 g de diacetato de clorexidina e 0,128 g de cetoconazol). Os ratos com ou sem os DIOs foram eutanasiados após 7 e 14 dias de avaliação. A análise histopatológica qualitativa foi realizada comparando-se fotomicrografias de secções histológicas, que foram obtidas utilizando um microscópio óptico que abrangeu transversalmente a região intermolares. As alterações morfológicas no epitélio e queratina foram analisadas quantitativamente através da realização de planimetria computadorizada. Os dados quantitativos foram analisados utilizando ANOVA 2-fatores e teste de Tukey (=0,05). A análise quantitativa mostrou que apenas o grupo com DIO contendo cetoconazol diminuiu significativamente a espessura e a área do estrato córneo em comparação com os outros grupos (p<0,05), que não apresentaram diferenças significativas entre si (p>0,05). Estes resultados estiveram de acordo com os obtidos para análise qualitativa. A incorporação de MCIs de nistatina e diacetato de clorexidina no Trusoft não induziram alterações histopatológicas na mucosa palatina de ratos, sugerindo a biocompatibilidade in vivo deste protocolo para o tratamento de estomatite protética. / Temporary resilient denture liners containing antifungal drugs have been suggested as an adjunct treatment for denture stomatitis. However, before clinically using these modified liners in humans, it is important to assess their biocompatibility in animal models. This study evaluated the in vivo biocompatibility of a temporary soft denture liner (Trusoft) modified by antimicrobial agents at their minimum inhibitory concentrations (MICs) for biofilm formation by Candida albicans. Methods: Acrylic intraoral devices (IODs) were individually made for 60 Wistar rats. The rats were divided into the following 6 groups (n=5): 3 control groups (Negative: without IOD; General: IOD without relining; Positive: IOD relined with Trusoft without drugs) and 3 experimental groups (IOD relined with Trusoft modified by drugs at MICs: 0.032 g for nystatin, 0.064 g for chlorhexidine diacetate, and 0.128 g for ketoconazole). The rats with or without the IODs were sacrificed after 7 or 14 days of evaluation. Histopathological qualitative analysis was performed by comparing photomicrographs of histological sections, which were obtained using an optical microscope that transversely covered the inter-molar region. Morphological changes in the epithelium and keratin were quantitatively analyzed by performing computerized planimetry. Quantitative data were analyzed using 2-way ANOVA and Tukey\'s test (=0.05). Quantitative analysis showed that only the group with IOD containing ketoconazole significantly decreased the thickness and area of the stratum corneum compared with the other groups (p<0.05), which showed no significant differences between each other (p>0.05). These results were in accordance with those obtained for qualitative analysis. Incorporation of MICs of nystatin and chlorhexidine diacetate in Trusoft did not induce histopathological changes in the palatal mucosa of rats, suggesting the in vivo biocompatibility of this protocol for treating denture stomatitis.

Com a crescente demanda por dispositivos implantáveis de suporte cardíaco (vulgarmente chamados de Coração Artificial) no tratamento da insuficiência cardíaca, surge a demanda por sistemas de transmissão de energia transcutânea (TET) para recarregamento das baterias implantadas. Esses sistemas reduzem os riscos de infecções, por não terem cabos atravessando a pele para alimentar os implantes; evitando também intervenções cirúrgicas reincidentes para troca de baterias. Normalmente, são pesquisados e testados sistemas TET por acoplamento magnético (indutivo) entre bobinas através da pele. Este trabalho propõe um modelo para o acoplamento por meio do campo elétrico, através de um capacitor, cujo dielétrico é constituído por polímeros (materiais biocompatíveis) e tecido biológico vivo (pele humana). Provas de conceito para transmissão de energia pelo acoplamento capacitivo apresentaram a possibilidade de mitigar problemas relacionados ao alinhamento axial exigido pelo acoplamento indutivo. Simulações computacionais de circuitos elétricos equivalentes ao acoplamento capacitivo foram confrontadas com experimentos in vitro e ex vivo, com tecidos vivos, validando o modelo proposto e servindo de base para o desenvolvimento de uma nova tecnologia. / Heart failure (HF) is a complex syndrome and a problem in the world. Ventricular assistive devices (VADs) are being used as target therapy in the treatment of HF. In order to avoid infectious due to the driveline passing through the patients, transcutaneous energy transmission systems (TET) have been developed to VADs. These TETs usually act by magnetic coupling between coils. The present work proposes a modeling for capacitive coupling through a dielectric composed of polymer and human skin. Bench tests demonstrated advantages over the axial alignment required by inductive systems. Computational simulations of the equivalent electric circuit for capacitive coupling were compared with in vitro experiments and validated the proposed model.

Over 600,000 bone-grafting operations are performed each year in the United States. The majority of the bone used for these surgeries comes from autografts that are limited in quantity or allografts with high failure rates. Current synthetic bone grafting materials have poor mechanical properties, handling characteristics, and bioactivity. The goal of this dissertation was to develop a clinically translatable bone tissue engineering scaffold with improved handling characteristics, bioactivity, and smart delivery modalities. We hypothesized that this could be achieved through the rational selection of Food and Drug Administration (FDA) approved materials that blend favorably with hydroxyapatite (HA), the principle mineral component in bone. This dissertation describes the development of smart bone tissue engineering scaffolds composed of the biodegradable amphiphilic polymer poly(D,L-lactic acid-co-ethylene glycol-co- D,L-lactic acid) (PELA) and HA. Electrospun nanofibrous HA-PELA scaffolds exhibited improved handling characteristics and bioactivity over conventional HApoly( D,L-lactic acid) composites. Electrospun HA-PELA was hydrophilic, elastic, stiffened upon hydration, and supported the attachment and osteogenic differentiation of rat bone marrow stromal cells (MSCs). These in vitro properties translated into robust bone formation in vivo using a critical-size femoral defect model in rats. Spiral-wrapped HA-PELA scaffolds, loaded with MSCs or a lowdose of recombinant human bone morphogenetic protein-2, templated bone formation along the defect. As an alternate approach, PELA and HA-PELA were viii rapid prototyped into three-dimensional (3-D) macroporous scaffolds using a consumer-grade 3-D printer. These 3-D scaffolds have differential cell adhesion characteristics, swell and stiffen upon hydration, and exhibit hydration-induced self-fixation in a simulated confined defect. HA-PELA also exhibits thermal shape memory behavior, enabling the minimally invasive delivery and rapid (>3 sec) shape recovery of 3-D scaffolds at physiologically safe temperatures (~ 50ºC). Overall, this dissertation demonstrates how the rational selection of FDA approved materials with synergistic interactions results in smart biomaterials with high potential for clinical translation.

Made available in DSpace on 2014-06-11T19:33:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-08-31Bitstream added on 2014-06-13T19:44:16Z : No. of bitstreams: 1 marcaccini_am_dr_arafo.pdf: 3610599 bytes, checksum: 65fbbd0cb1b0657f1b361bf4e461a54e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os objetivos deste estudo foram avaliar o efeito de biomateriais associados ao PRP na formação óssea em defeitos padronizados de rádio e avaliar o efeito de PRP+RTG+enxerto ósseo autógeno para tratamento de lesões de furca grau II em cães. Para tal, em um primeiro estudo, foram confeccionados 5 defeitos de 5mm em cada rádio (direito e esquerdo) em 05 cães, constituindo assim espaços para preenchimento com os enxertos ou substitutos ósseos avaliados, totalizando 50 cavidades. Os materiais testados foram DFDBA, vidro bioativo, osso autógeno e osso mineral bovino, associados ou não ao PRP. Estes grupos foram avaliados e comparados com os grupos representados por coágulo sangüíneo e PRP. Ao final de 60 dias, foi realizada biópsia e preparo laboratorial para avaliação histológica e histomorfométrica. Os grupos que apresentaram melhores resultados foram coágulo, PRP e osso autógeno associado ou não a PRP; e a utilização do PRP não promoveu maior formação óssea em relação aos demais grupos, com exceção do vidro bioativo+PRP que apresentou os melhores resultados. No segundo estudo, foram criados cirurgicamente defeitos periodontais de furca nos quartos pré-molares mandibulares, bilateralmente em 5 cães, cronificados por um período de três meses e tratados por PRP/RTG/enxerto ósseo autógeno (grupo experimental) ou RTG/enxerto ósseo autógeno (grupo controle). Quatro meses após o tratamento, os cães foram sacrificados. Na área de furca, houve maior preenchimento ósseo e extensão linear de novo cemento, nova adaptação conjuntiva e regeneração periodontal no grupo experimental (p<0.005) e maior extensão linear de epitélio no grupo controle (p<0.005). A associação do PRP a RTG e enxerto ósseo autógeno proporcionou maior regeneração dos tecidos periodontais. Portanto, o PRP promoveu melhores resultados na formação óssea somente... . / The aims of this study were to evaluate the effect of biomaterials in association to PRP on bone formation, in padronized defects of radius, and evaluate the effect of PRP/GTR/autogenous bone graft in the treatment of Class II furcation lesions in dogs. For that, in a first study, five defects of 5mm each were produced in each radius (left and right) in 5 dogs, so creating spaces to be filled with grafts or the bone substitutes under study, totalling 50 cavities. The biomaterials tested were DFDBA, bioglass, autogenous bone and bovine mineral bone grafts, associated, or not, with PRP. These biomaterials were compared with coagulum and PRP. At the end of 60 days biopsy was done and histological laminas were prepared. Under the experimental condictions, coagulum, PRP and autogenous bone associated or not to PRP presented the best results, with more new bone formation; and no difference was observed between the groups with biomaterials, associated or not with PRP, excepting bioactive glass/PRP which showded the best results. In the second study, periodontal furcation defects were surgically produced bilaterally in the fourth mandibular premolars in 5 dogs, cronified for 3 months and treated with PRP/GTR/autogenous bone graft (experimental group) or GTR/autogenous bone graft (control group). Four months after the treatment, the dogs were sacrified. In the furcation area, more bone filling and linear extension of new cement, new conjunctive adaptation and periodontal regeneration were observed to occur in the experimental group (p<0.005) and more linear extension of epitelium in the control group (p<0.005). The association PRP/GTR/autogenous bone graft was observed to produce more regeneration of periodontal tissues. Therefore, the PRP association showed the best results in bone formation only at bioactive glass group; and... (Complete abstract, click electronic address below).

Orientador: Elcio Marcantonio Junior / Banca: Joni Augusto Cirelli / Banca: Enilson Antonio Sallum / Banca: Luis Carlos Spolidorio / Banca: Paulo Tambasco de Oliveira / Resumo: Os objetivos deste estudo foram avaliar o efeito de biomateriais associados ao PRP na formação óssea em defeitos padronizados de rádio e avaliar o efeito de PRP+RTG+enxerto ósseo autógeno para tratamento de lesões de furca grau II em cães. Para tal, em um primeiro estudo, foram confeccionados 5 defeitos de 5mm em cada rádio (direito e esquerdo) em 05 cães, constituindo assim espaços para preenchimento com os enxertos ou substitutos ósseos avaliados, totalizando 50 cavidades. Os materiais testados foram DFDBA, vidro bioativo, osso autógeno e osso mineral bovino, associados ou não ao PRP. Estes grupos foram avaliados e comparados com os grupos representados por coágulo sangüíneo e PRP. Ao final de 60 dias, foi realizada biópsia e preparo laboratorial para avaliação histológica e histomorfométrica. Os grupos que apresentaram melhores resultados foram coágulo, PRP e osso autógeno associado ou não a PRP; e a utilização do PRP não promoveu maior formação óssea em relação aos demais grupos, com exceção do vidro bioativo+PRP que apresentou os melhores resultados. No segundo estudo, foram criados cirurgicamente defeitos periodontais de furca nos quartos pré-molares mandibulares, bilateralmente em 5 cães, cronificados por um período de três meses e tratados por PRP/RTG/enxerto ósseo autógeno (grupo experimental) ou RTG/enxerto ósseo autógeno (grupo controle). Quatro meses após o tratamento, os cães foram sacrificados. Na área de furca, houve maior preenchimento ósseo e extensão linear de novo cemento, nova adaptação conjuntiva e regeneração periodontal no grupo experimental (p<0.005) e maior extensão linear de epitélio no grupo controle (p<0.005). A associação do PRP a RTG e enxerto ósseo autógeno proporcionou maior regeneração dos tecidos periodontais. Portanto, o PRP promoveu melhores resultados na formação óssea somente... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: The aims of this study were to evaluate the effect of biomaterials in association to PRP on bone formation, in padronized defects of radius, and evaluate the effect of PRP/GTR/autogenous bone graft in the treatment of Class II furcation lesions in dogs. For that, in a first study, five defects of 5mm each were produced in each radius (left and right) in 5 dogs, so creating spaces to be filled with grafts or the bone substitutes under study, totalling 50 cavities. The biomaterials tested were DFDBA, bioglass, autogenous bone and bovine mineral bone grafts, associated, or not, with PRP. These biomaterials were compared with coagulum and PRP. At the end of 60 days biopsy was done and histological laminas were prepared. Under the experimental condictions, coagulum, PRP and autogenous bone associated or not to PRP presented the best results, with more new bone formation; and no difference was observed between the groups with biomaterials, associated or not with PRP, excepting bioactive glass/PRP which showded the best results. In the second study, periodontal furcation defects were surgically produced bilaterally in the fourth mandibular premolars in 5 dogs, cronified for 3 months and treated with PRP/GTR/autogenous bone graft (experimental group) or GTR/autogenous bone graft (control group). Four months after the treatment, the dogs were sacrified. In the furcation area, more bone filling and linear extension of new cement, new conjunctive adaptation and periodontal regeneration were observed to occur in the experimental group (p<0.005) and more linear extension of epitelium in the control group (p<0.005). The association PRP/GTR/autogenous bone graft was observed to produce more regeneration of periodontal tissues. Therefore, the PRP association showed the best results in bone formation only at bioactive glass group; and... (Complete abstract, click electronic address below). / Doutor

Topographical and mechanical properties of adhesive substrates provide important biological cues that affect cell spreading, migration, growth, and differentiation. The phenomenon has led to the increased use of topographically patterned and flexible substrates in studying cultured cells. However, these studies may be complicated by various limitations. For example, the effects of ligand distribution and porosity are affected by topographical features of 3D biological constructs. Similarly, many studies of mechanical cues are compounded with cellular deformation from external forces, or limited by comparative studies of separate cells on different substrates. Furthermore, understanding cell responses to mechanical input is dependent upon reliable measurements of mechanical properties. This work addresses each of these issues. To determine how substrate topography and focal adhesion kinase (FAK) affect cell shape and movement, I studied FAK-null (FAK -/-) and wild type mouse 3T3 fibroblasts on chemically identical polystyrene substrates with either flat surfaces or micron-sized pillars, I found that, compared to cells on flat surfaces, those on pillar substrates showed a more branched shape, an increased linear speed, and a decreased directional stability, which were dependent on both myosin-II and FAK. To study the dynamic responses to changes in substrate stiffness without other confounding effects, I developed a UV-modulatable substrate that softens upon UV irradiation. As atomic force microscopy (AFM) proved inadequate to detect microscale changes in stiffness, I first developed and validated a microsphere indentation method that is compatible with fluorescence microscopy. The results obtained with this method were comparable to those obtained with AFM. The UV-modulatable substrates softened by ~20-30% with an intensity of irradiation that has no detectable effect on 3T3 cells on control surfaces. Cells responded to global softening of the substrate with an initial retraction followed by a gradual reduction in spread area. Precise spatial control of softening is also possible - while there was little response to posterior softening, anterior softening elicited a pronounced retraction and either a reversal of cell polarity or a significant decrease in spread area if the cells move into the softened region. In conclusion, these techniques provide advances in gaining mechanistic insight into cellular responses to topographical and mechanical cues. Additionally, there are various other potential applications of the novel UV-softening substrate, particularly in regenerative medicine and tissue engineering.

Indiana University-Purdue University Indianapolis (IUPUI) / Brasseler USA (Savannah, GA) developed and introduced a bioceramic putty called EndoSequence Root Repair Material (ERRM) that can be used as a retrofilling material for surgical endodontics. The material is said to have many of the same chemical, physical, and biological properties as mineral trioxide aggregate (MTA), but with superior handling characteristics. The material is composed of calcium silicates, monobasic calcium phosphate, zirconium oxide, tantalum oxide, proprietary fillers, and thickening agents. ERRM is said by the manufacturer to bond to adjacent dentin, have no shrinkage, be highly biocompatible, hydrophilic, radiopaque, and antibacterial due to a high pH during setting. Investigations on the sealing properties of this material have not yet been conducted. The purpose of this study was to compare the microbial leakage of Enterococcus faecalis in teeth with root-end fillings using ProRoot MTA and Brasseler’s ERRM in a dual-chamber bacterial leakage model as described by Torabinejad and colleagues. The aim of this investigation was to compare the bacterial microleakage of these two root-end filling materials exists. Sixty-two human, single-rooted, mandibular premolars in which extraction was indicated were accessed and instrumented in an orthograde fashion with hand and rotary files. Root resection of the apical 3 mm was then completed and root-end retropreparations were created for placement of root-end filling material. Twenty-seven of these premolars had root-end fillings using ProRoot MTA and 27 had root-end fillings using ERRM. Two teeth were used as a positive control group with no root-end filling, and two other teeth were used as a negative control group and were sealed and coated with dentin bonding agent. The teeth were then evaluated for microleakage using a dual-chamber bacterial microleakage model for 40 days as described by Torabinejad and colleagues. Microleakage was determined by the presence of turbidity in the lower chamber of the apparatus and was assessed each day. Fresh samples of E. faecalis were used every three days to inoculate the apparatus and serve as a bacterial challenge for the materials. Results were recorded every day for 30 days. The outcome of interest (bacterial turbidity) and time-to-leakage (in days) were determined for each of the samples. Survival analysis was used to compare the two groups with a Kaplan-Meier plot to visualize the results and a nonparametric log-rank test for the group comparison. The microleakage of ERRM was not statistically different (p > 0.05) than leakage of ProRoot MTA when subjected to E. faecalis over the 40 day observation period. Both groups had a small number of early failures (within 4 days) and no leakage was observed for the remaining 40 days of the study. Therefore, the null hypothesis was rejected. The results of this research support the use of either of these two materials when compared with the controls. The microleakage of Brasseler’s EndoSequence Root Repair Material was at least as good as ProRoot Mineral Trioxide Aggregate when tested with E. faecalis.