Made available in DSpace on 2015-04-14T13:58:54Z (GMT). No. of bitstreams: 1 443125.pdf: 1527521 bytes, checksum: 2c9a9ef7ac02480e7ed3b2734a8acc04 (MD5) Previous issue date: 2012-08-22 / Peripheral nerve injury accident is a common type of lesion that can cause loss of mobility and decrease the quality of life. Despite advances in the biomedical area, there are few cases where there is complete functional recovery of a damaged nerve. The application of biodegradable polymers such as poly(lactide-co-glycolide) (PLGA), shows a viable alternative of treatment in peripheral nerves injuries for presenting mechanical strength, biocompatibility and controlled degradation, being also an excellent material for drug delivery. A PLGA scaffold should be porous with pore sizes on the order of micro-and nanometer, which offers the possibility to insert growth factors, promoting a constant release of these biological structures. The aim of this research is to produce porous scaffolds of PLGA. This was achieved by dissolving the polymer in chloroform, adding a porogenic compound. A titanium rod with 2mm in diameter was deeped in the suspension obtained and dried in a hood, obtaining a layer of PLGA / porogen agent on the surface of the rod. In sequence, the rod was immersed in a solution of PLGA with chloroform. After dried for 2 hours in a hood, the titanium rods were submerged in deionized water for 48 hours, during which the water was changed every 8 hours in order to remove the porogenic agent. After this process, the tubular structures formed were easily removed from the rods. Finally, the prepared tubes were divided into groups and treated with different concentrations of sodium hydroxide, to create pores in the order of nanometers, and subsequently vacuum dried for 48 hours. The structures obtained were characterized by XRD, FTIR, SEM and the in vitro degradation was monitored by GPC. / Danos a nervos perif?ricos s?o formas comuns de les?es que podem causar perda de mobilidade e diminuir a qualidade de vida. Apesar dos avan?os no campo biom?dico, existem poucos casos em que h? recupera??o funcional completa de um nervo danificado. A aplica??o de pol?meros biodegrad?veis tais como PLGA, apresenta uma alternativa vi?vel no tratamento de les?es de nervos perif?ricos por possuir resist?ncia mec?nica, biocompatibilidade e degrada??o controlada. Uma matriz de PLGA deve apresentar poros na ordem de micr?metros e nan?metros, oferecendo a possibilidade de inclus?o de fatores de crescimento e possivelmente promovendo uma liberta??o constante destas estruturas biol?gicas. O objetivo desta pesquisa ? produzir matrizes porosas de PLGA. Isto foi realizado atrav?s da dissolu??o do pol?mero em clorof?rmio, seguida da adi??o de um composto porog?nico. Uma haste de tit?nio com 2mm de di?metro foi imersa na suspens?o obtida e quando retirada, foi seca em capela, obtendo uma camada de PLGA/agente porog?nico na superf?cie da haste. Na sequ?ncia, a haste foi imersa em uma solu??o de PLGA com clorof?rmio. Ap?s seca durante 2h em capela, as hastes de tit?nio foram submersas em ?gua deionizada durante 48h, durante as quais, a ?gua foi trocada a cada 8h, para remo??o do agente porog?nico. Ap?s este processo, as estruturas tubulares formadas s?o facilmente removidas das hastes. Finalmente, os tubos confeccionados foram divididos em grupos, e tratados com diferentes concentra??es de hidr?xido de s?dio, para cria??o de poros na ordem de nan?metros, sendo, subsequentemente, secos em forno a v?cuo durante 48h. As estruturas obtidas foram caracterizadas por XRD, FTIR, MEV e a degrada??o in vitro foi acompanhada por GPC.

Made available in DSpace on 2015-04-14T13:35:35Z (GMT). No. of bitstreams: 1 443023.pdf: 2231703 bytes, checksum: 8fa714244d8e44469edc5dc83e9b3038 (MD5) Previous issue date: 2012-08-29 / Injuries to the peripheral nervous system present a challenge for regenerative medicine. The study investigated the effects of platelet-rich plasma (PRP) and erythropoietin (EPO), alone or in combination, in the regeneration of peripheral nerve in rats. The work was developed in three phases using 70 rats. The first phase, evaluated the platelet concentration and growth factors production/release (TGF-β, PDGF, VEGF and αβ) in three protocols for obtaining PRP (A, B and C) obtained by aortic or cardiac puncture. Cardiac puncture in association with A protocol showed the best results. In the second stage, using best results methods at the first stage, was produced two PRP concentrations (1,000,000 and 2,000,000 platelets.μl-1; PRP1 and PRP2, respectively) for applying in the rats sciatic nerve. Comparison of concentrations with autologous nerve graft (ANG) and saline solution (SS) groups showed benefits in the use of PRP2. In the third phase (same experimental model) were added PRP2 + EPO and EPO groups. The animals of phases 1 and 2 were evaluated by walking track test and histomorphometric analysis (toluidine blue) and showed benefits in autologous nerve graft (ANG) with respect to tubulization (independent of regenerative factor). For tubularized animals, the study showed advantages for PRP and EPO simultaneous use followed by EPO group. Finally, it was observed that PRP 2,000,000 platelets.μl-1 has beneficial effects when compared to PRP 1,000,000 platelets.μl-1 for peripheral neuroregeneration rats. / Les?es ao sistema nervoso perif?rico representam um desafio para a medicina regenerativa. O estudo objetivou conhecer os efeitos do plasma rico em plaquetas (PRP) e da eritropoietina (EPO), isolados ou combinados, na regenera??o do nervo perif?rico de ratos. O trabalho desenvolveu-se em tr?s etapas utilizando 70 ratos. A primeira fase avaliou a concentra??o plaquet?ria e produ??o/libera??o de fatores de crescimento (TGF-β, PDGF-αβ e VEGF) em tr?s protocolos de obten??o do PRP (A, B e C) obtidos por pun??o a?rtica ou card?aca. A pun??o card?aca em associa??o com protocolo A gerou os melhores resultados. Na segunda fase, usando os m?todos com melhores resultados na primeira etapa, produziram-se duas concentra??es de PRP (1.000.000 e 2.000.000 plaquetas. μl-1; PRP1 e PRP2, respectivamente) para aplica??o no nervo ci?tico tubulizado de ratos. Compara??o das concentra??es entre si e com grupos auto enxerto (AE) e solu??o fisiol?gica (SF) evidenciaram benef?cios no uso de PRP2. Na terceira fase (mesmo modelo experimental), foram adicionados os grupos EPO e EPO+PRP2. Os animais das fases 1 e 2 foram avaliados por teste de marcha e histomorfometria (azul de toluidina) e demonstraram que o auto enxerto apresentou benef?cios sobre a tubuliza??o (independente do fator regenerativo utilizado). Para os animais tubulizados, o estudo demostrou melhores resultados para o uso simult?neo de PRP e EPO, seguido do grupo EPO. Finalizando, observou-se que a aplica??o de PRP na concentra??o de 2.000.000 plaquetas.μl-1 em compara??o com 1.000.000 platelets.μl- 1 apresentou vantagens para neuroregenera??o perif?rica de ratos.

Made available in DSpace on 2015-04-14T13:36:01Z (GMT). No. of bitstreams: 1 464259.pdf: 3964531 bytes, checksum: 04739dfcb6adbc45be2c0bbc0dde167b (MD5) Previous issue date: 2014-08-29 / Introduction : Injuries in peripheral nerves are common in clinical practice being responsible for serious problems and often permanent as loss of motor, sensitive functions, acute and chronic pain. Although surgical, physiotherapy and diagnostic techniques have evolved in recent decades, the clinical outcomes of nerve recovery still unsatisfactory, which encourages many researchers to seek drugs and devices that may help regeneration (NOBLE et al, 1998; OLIVEIRA et al, 2004). Various trophic factors, also known as growth factors (GF) are used and tested in vitro and in vivo in an attempt to assist the regeneration of peripheral nerves. These proteins act directly on the proliferation and differentiation of various cell types, being able to promote tissue repair and functional recovery (BOYD AND GORDON, 2003). Among them, we highlight the FK506 (Tacrolimus), a ligand for immunophilins with strong immunosuppressive effect that has potential neurotrophic and neuroprotective actions. Studies have shown that FK506 increases the rate of axonal regeneration and also the level of necessary reinnervation after peripheral nerve injury, besides enhancing recovery from nerve damage. Objective : Evaluating in vivo the availability and effect of FK 506 on the repair of injury of rat sciatic nerve. Material and Methods : Thirty-six male adult Wistar rats were randomized into three groups (I - control, II - Systemic FK506 III - FK506 site;). To evaluate the effect of different treatments, the sciatic nerve of animals was transected, creating a defect of 10 mm and then tubulized with the silicone chamber. In the control group, no additional treatment was performed. In systemic group, FK506 (dose 0.1 mg/kg/day) was administered systemically via osmotic minipump ALZET while in the local group the administration also occurred through the ALZET osmotic minipump, but adapted to release into the silicone chamber the same dose. The performed treatment lasted 90 days. Results : Data from the present study suggest that the immunosuppressive drug FK506 has a positive effect on the nervous functional improvement and the use of osmotic minipumps is effective in continuous dispensing of the drug. The most important finding of this research is that the degree of functional recovery, measured by the rate of sciatic function after injury with loss of substance and repair through tubing, it is better when FK506 is administered locally whether compared to systemic administration in animal models. No other studies have used local application of the drug with constant release rate for comparison were found. / Introdu??o : Les?es em nervos perif?ricos s?o frequentes na pr?tica cl?nica sendo respons?veis por problemas graves e muitas vezes permanentes como perda de fun??es motoras, sensitivas, dor aguda e cr?nica. Embora as t?cnicas cir?rgicas, fisioter?picas e de diagn?stico tenham evolu?do nas ?ltimas d?cadas, os desfechos cl?nicos de recupera??o nervosa continuam insatisfat?rios, o que estimula diversos pesquisadores a buscarem drogas e dispositivos que possam auxiliar na regenera??o (NOBLE et al, 1998; OLIVEIRA et al, 2004). Diversos fatores tr?ficos, tamb?m conhecidos como fatores de crescimento (FC), s?o utilizados e testados in vitro e in vivo como uma tentativa de auxiliar a regenera??o de nervos perif?ricos.Essas prote?nas atuam diretamente na prolifera??o e diferencia??o de diversos tipos celulares, sendo capazes de promover reparo tecidual e recupera??o funcional (BOYD E GORDON, 2003). Dentre eles, destaca-se o FK506 (Tacrolimus), um ligante de imunofilinas com forte efeito imunossupressor que apresenta potenciais a??es neurotr?ficas e neuroprotetoras. Estudos t?m mostrado que o FK506 aumenta a taxa de regenera??o axonal e tamb?m o n?vel de reinerva??o necess?ria ap?s les?o do nervo perif?rico, al?m de melhorar a recupera??o ap?s les?es no nervo. Objetivo : Avaliar in vivo a viabilidade e efeito do FK 506 sobre o reparo de les?o de nervo ci?tico de ratos Material e M?todos : Trinta e seis ratos Wistar, machos, adultos foram randomicamente distribu?dos em tr?s grupos (I controle; II FK506 sist?mico; III FK506 local;). Para avaliar o efeito dos diferentes tratamentos, o nervo ci?tico dos animais foi transeccionado criando um defeito de 10mm e, em seguida, tubulizado com c?mara de silicone. No grupo controle, nenhum tratamento adicional foi realizado. No grupo sist?mico, o FK506 (dose 0,1mg/kg/dia) foi administrado sistemicamente via minibomba osm?tica ALZET enquanto que no grupo local a administra??o tamb?m ocorreu atrav?s da minibomba osm?tica ALZET, mas adaptada para libera??o dentro da c?mara de silicone na mesma dose. O tratamento empregado teve dura??o de 90 dias. Resultados : Os dados do presente estudo sugerem que a droga imunossupressora FK506 possui efeito positivo na melhora funcional nervosa e o uso de minibombas osm?ticas ? eficaz na dispensa??o cont?nua da droga. O dado mais importante dessa pesquisa ? que o grau de recupera??o funcional, medido atrav?s do ?ndice de fun??o ci?tica ap?s les?o com perda de subst?ncia e reparo atrav?s de tubuliza??o, ? melhor quando o FK506 ? administrado localmente se comparado ? administra??o sist?mica em modelos animais. N?o foram encontrados outros trabalhos que tenham usado aplica??o local da droga com taxa de libera??o constante para efeitos de compara??o.