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Previous issue date: 2017-08-14 / Os nanotubos de carbono de multicamadas (MWCNT) incorporados ? materiais de origem proteicas podem contribuir para o surgimento de interessantes biomateriais comp?sitos com grande potencial de aplica??es biol?gicas. Os MWCNT s?o promissores vetores de DNA em c?lulas e embri?es de seres vivos. Por?m, o desencadeamento do seu uso na ?rea biom?dica est? relacionado ? padroniza??o de sistemas e protocolos para avaliar os potenciais impactos na sa?de humana e no meio ambiente. O objetivo geral deste estudo foi avaliar o efeito da funcionaliza??o, a citotoxicidade e a ades?o celular dos nanotubos de carbono na sua forma comercial e modificados por diferentes processos em c?lulas macr?fagos (J774 e RAW). Nesta pesquisa, inicialmente foram realizados diferentes processos de funcionaliza??o nos MWCNT visando a inser??o de grupos funcionais e poss?vel compatibilidade com biopol?meros. Ap?s a funcionaliza??o os MWCNT foram caracterizados por diferentes t?cnicas e realizados os ensaios de citotoxicidade e a eletroan?lise. Os biopol?meros utilizados para a funcionaliza??o do substrato t?xtil da prote?na da soja foram o col?geno extra?do da pele da til?pia e o col?geno comercial. Os substratos t?xtis foram funcionalizados atrav?s do processo Dip coating e em seguida, foram incorporados os nanotubos de carbono pelo mesmo processo. Os resultados obtidos atrav?s das an?lises do processo de funcionaliza??o dos MWCNT revelaram que as amostras funcionalizadas com a quitosana tende a aumentar o di?metro do tubo devido a forma??o de uma monocamada polim?rica em sua superf?cie e que os melhores resultados de oxida??o foram para as amostras que passaram pelo processo de funcionaliza??o ?cida e funcionaliza??o ?cida com quitosana. Os resultados obtidos pela Espectroscopia Raman comprovaram que o processo de funcionaliza??o foi realizado com ?xito, possibilitando a inser??o de grupos funcionais sobre os nanotubos. A eletroan?lise nos nanotubos mostraram que os maiores valores da capacit?ncia por massa e por ?rea foram para as amostras funcionalizadas com ?cidos e que a adi??o da quitosana durante a funcionaliza??o aumenta a resist?ncia ? passagem da corrente, al?m de provocar um efeito isolante. Os ensaios de citotoxicidade dos MWCNT realizadas em macr?fagos nas concentra??es de 100, 75, 50, 25 e 5 ?g/mL demonstraram um percentual em torno de 95% de viabilidade celular para as amostras funcionalizadas com ?cido e quitosana para todas as concentra??es. Os ensaios de ades?o celular nos MWCNT revelaram excelentes intera??es em concentra??es mais elevadas para todas as amostras de nanotubos. A observa??o visual do efeito da modifica??o do substrato t?xtil com o col?geno indicou que o tipo e a origem da prote?na interferem no efeito da imobiliza??o dos nanotubos de carbono. Em conclus?o, as exposi??es de macr?fagos a baixas concentra??es de MWCNT funcionalizados n?o causaram impacto na viabilidade celular, o que abre as possibilidades de diversos estudos para potencializar aplica??es na ?rea biol?gica. / The multiwalled carbon nanotubes (MWCNT) incorporated into the materials of protein origin can contribute to the emergence of interesting composite biomaterials with great potential of biological applications. MWCNT are promising DNA vectors in living cells and embryos. However, the triggering of its use in the biomedical area is related to the standardization of systems and protocols to assess the potential impacts on human health and the environment. The general objective of this study was to evaluate the effect of functionalization, cytotoxicity and cellular adhesion of carbon nanotubes in their commercial form and modified by different processes in macrophages (J774 and RAW). In this research, different functionalization processes were initially performed in the MWCNT, aiming at the insertion of functional groups and possible compatibility with biopolymers. After functionalization, the MWCNT were characterized by different techniques and performed the cytotoxicity and electroanalysis tests. The biopolymers used for the functionalization of the textile substrate of the soy protein were the collagen extracted from the skin of the tilapia and the commercial collagen. The textile substrates were functionalized through the dip coat process and then the carbon nanotubes were incorporated by the same process. The results obtained through the analysis of the functionalization process of the MWCNT revealed that the functionalized samples with chitosan tend to increase the diameter of the tube due to the formation of a polymeric monolayer on its surface and that the best oxidation results were for the samples that passed by the process of acid functionalization and acid functionalization with chitosan. The results obtained by Raman Spectroscopy proved that the functionalization process was successful, allowing the insertion of functional groups on the nanotubes. The electroanalysis in the nanotubes showed that the highest values of capacitance per mass and per area were for the acid functionalized samples and that the addition of chitosan during functionalization increases the resistance to current flow, besides provoking an insulating effect. The cytotoxicity tests of MWCNT performed on macrophages at concentrations of 100, 75, 50, 25 and 5 ?g / mL demonstrated a percentage of around 95% cell viability for acid and chitosan functionalized samples at all concentrations. Cell adhesion assays in MWCNTs showed excellent interactions at higher concentrations for all nanotube samples. Visual observation of the effect of modification of the textile substrate with collagen indicated that the type and origin of the protein interfere with the immobilization effect of the carbon nanotubes. In conclusion, macrophage exposures at low concentrations of functionalized MWCNT had no impact on cell viability, which opens the possibilities of several studies to potentiate applications in the biological field.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/24646 |
| Date | 14 August 2017 |
| Creators | Holanda, Elis?ngela Bezerra das Neves |
| Contributors | 18222161415, Lima, Andrea, 88346242204, Huitle, Carlos Alberto Martinez, 01139059980, Santos, Elaine Cristina Martins de Moura, 97143936472, Silva, Iris Oliveira da, 03675707423, Nascimento, Jos? Heriberto Oliveira do, 02452573493, Silva, Kesia Karina de Oliveira Souto, 00851738435, Ladchumananandasivam, Rasiah |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA MEC?NICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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