Estudo da incorporação e liberação de peptídeos hormonais utilizando membranas de látex natural como carreador
Carregando...
Arquivos
Data
2016-02-25
Autores
Barros, Natan Roberto de [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O látex extraído da seringueira Hevea brasiliensis têm mostrado promissores resultados em aplicações biomédicas, onde membranas produzidas deste material têm sido utilizadas como próteses e enxertos médicos devido às suas características de biocompatibilidade e estímulo natural à angiogênese. O objetivo desse trabalho consiste na incorporação de peptídeos em membranas de látex natural e no estudo de suas liberações. Esperamos com os resultados, viabilizar o uso do látex natural como sistema de liberação sustentada de peptídeos e/ou proteínas. A taxa de liberação dos peptídeos foi monitorada e quantificada por Cromatografia Líquida de Alta Eficiência (CLAE) em modo analítico. A incorporação do peptídeo às membranas de látex acompanhou diferentes caracterizações, dentre elas: Espectroscopia de Infravermelho por Transformada de Fourier (FTIR) que identificou a estabilidade dos peptídeos após incorporação ao látex natural pela preservação de bandas características para os peptídeos, dentre elas, as bandas 1643 – 1638 cm-1 deformação NH de aminas e C=O de amidas; 1524 - 1514 cm-1 deformação C=C de aromáticos; e 542 – 498 cm-1 deformação S-S, Capacidade de absorção de fluídos, Perda de massa em soluções aquosas, CLAE e Microscopia Eletrônica de Varredura (MEV). Durante os ensaios de liberação dos peptídeos pelas membranas de látex natural, observou-se a instabilidade dos peptídeos em solução, com degradação total em períodos que variaram de 48 a 120 horas nos valores de pH 7,4; 12,0; e água destilada (pH 5,6 – 6,4). Entretanto, para a solução de tampão acetato pH 4,0 não houve instabilidade dos peptídeos em solução. Desta forma, estes resultados sugerem a possível interferência causada por proteases alcalinas presentes no látex natural. Adicionalmente, com o propósito de eliminar das membranas o agente causador da degradação dos peptídeos, foram confeccionadas novas membranas submetidas ao tratamento de lavagem, e posteriormente os peptídeos foram adsorvidos às membranas. Durante os ensaios de liberação foi possível observar a liberação e a estabilidade dos peptídeos com liberação de 60% em 96 horas para o peptídeo desmopressina; 90% em 24 horas para somatostatina; 45% em 8 horas para ocitocina; e 80% em 24 horas para octreotida. A partir destes resultados podemos afirmar que o látex natural pode ser utilizado como matriz sólida na liberação tópica de peptídeos, no entanto, se faz necessária maior investigação sobre as enzimas proteolíticas presentes no látex natural extraído da seringueira Hevea brasiliensis.
The latex extracted from Hevea brasiliensis rubber tree have shown promising results in biomedical applications, where membranes produced from this material have been used as medical implants and grafts, due to its biocompatibility and natural stimulation of angiogenesis. The aim of this work was to incorporate peptides into natural latex membranes and the study of its release. We look forward to the results, enabling the use of natural latex as Controlled Release System of peptides and/or proteins. The rate of peptide release were monitored and quantified by High Performance Liquid Chromatography (HPLC) in an analytical way. The peptides incorporation into latex membranes followed different characterizations, such as: Fourier Transform Infrared Spectroscopy (FTIR) which identified the stability of peptides after incorporation into the natural latex by the preservation of characteristic bands for peptides, among them, 1643 - 1638 cm-1 NH strain of amines and amides C=O; 1524 - 1514 cm-1 strain C=C aromatic; and 542 - 498 cm-1 strain S-S, fluid absorption capacity, the loss in weight in aqueous solutions, HPLC and Scanning Electron Microscopy (SEM). During the release tests of peptides by the natural latex membranes, it was observed instability of the peptides in solution, with total extinction in periods that ranged between 48 and 120 hours in pH 7.4; 12.0; and distilled water (pH 5.6 - 6.4). However, for acetate buffer solution (pH 4.0) was not observed instability of peptides. Therefore, these results suggest that there are possible interferences caused by alkaline proteases present in the natural latex. Additionally, in order to remove the causative agent of degradation, were prepared new membranes subjected to washing treatment, and the peptides posteriorly adsorbed on the membranes. During the release tests, it was possible to observe the release and stability of peptides with 60% released at 96 hours for the peptide desmopressin; 90% in 24 hours for somatostatin; 45% in 8 hours for oxytocin; and 80% at 24 hours for octreotide. From these results we can say that the natural latex can be used as solid matrix in the topical & transdermal delivery of peptides, however, it is necessary further research into the proteolytic enzymes present in the natural latex extracted from the rubber tree Hevea brasiliensis.
The latex extracted from Hevea brasiliensis rubber tree have shown promising results in biomedical applications, where membranes produced from this material have been used as medical implants and grafts, due to its biocompatibility and natural stimulation of angiogenesis. The aim of this work was to incorporate peptides into natural latex membranes and the study of its release. We look forward to the results, enabling the use of natural latex as Controlled Release System of peptides and/or proteins. The rate of peptide release were monitored and quantified by High Performance Liquid Chromatography (HPLC) in an analytical way. The peptides incorporation into latex membranes followed different characterizations, such as: Fourier Transform Infrared Spectroscopy (FTIR) which identified the stability of peptides after incorporation into the natural latex by the preservation of characteristic bands for peptides, among them, 1643 - 1638 cm-1 NH strain of amines and amides C=O; 1524 - 1514 cm-1 strain C=C aromatic; and 542 - 498 cm-1 strain S-S, fluid absorption capacity, the loss in weight in aqueous solutions, HPLC and Scanning Electron Microscopy (SEM). During the release tests of peptides by the natural latex membranes, it was observed instability of the peptides in solution, with total extinction in periods that ranged between 48 and 120 hours in pH 7.4; 12.0; and distilled water (pH 5.6 - 6.4). However, for acetate buffer solution (pH 4.0) was not observed instability of peptides. Therefore, these results suggest that there are possible interferences caused by alkaline proteases present in the natural latex. Additionally, in order to remove the causative agent of degradation, were prepared new membranes subjected to washing treatment, and the peptides posteriorly adsorbed on the membranes. During the release tests, it was possible to observe the release and stability of peptides with 60% released at 96 hours for the peptide desmopressin; 90% in 24 hours for somatostatin; 45% in 8 hours for oxytocin; and 80% at 24 hours for octreotide. From these results we can say that the natural latex can be used as solid matrix in the topical & transdermal delivery of peptides, however, it is necessary further research into the proteolytic enzymes present in the natural latex extracted from the rubber tree Hevea brasiliensis.
Descrição
Palavras-chave
Látex natural, Peptídeo, Liberação sustentada, Biomaterial, Natural rubber latex, Peptide, Controlled release, Biomaterial