Síntese, caracterização e avaliação da potencialidade de uso de MOFs para o estudo de atividade antimicrobiana
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2021-04-09
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Universidade Estadual Paulista (Unesp)
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Ao longo das últimas décadas, a resistência aos antimicrobianos tem sido um objeto muito importante de estudo. O uso indiscriminado de antibióticos leva a seleção de cepas bacterianas resistentes e, com isso, pesquisadores buscam estratégias mais eficientes na erradicação de microrganismos. Dentro dessa perspectiva, as redes metalorgânicas (ou MOFs, Metal-Organic Frameworks) podem ser uma alternativa. Trata-se de uma subclasse dos polímeros de coordenação com estrutura aberta contendo cavidades potencialmente disponíveis (poros). Devido as suas propriedades intrínsecas como elevada área específica, cristalinidade, estabilidade térmica, porosidade permanente entre outras, as MOFs apresentam potencial aplicação em diversas áreas como armazenamento e separação de gases, catálise heterogênea, drug delivery, sensores químicos, entre outras. Desta forma, o objetivo principal desse trabalho é a síntese em nanoescala de uma estrutura MOF biocompátivel (BMMg e MIL-100(Fe)), a caracterização, a incorporação do antibiótico estreptomicina (Estrep.) e a avaliação da atividade antibacteriana de MIL-100(Fe)@Estrep.. A estrutura BMMg foi obtida a partir dos precursores cloreto de magnésio, ácido tereftálico e adenina em diferentes proporções pelo método solvotérmico e a MIL-100(Fe) pelo método assistido por micro-ondas, a partir da mistura de cloreto de ferro (III) e o ácido trimésico (1,3,5-benzenotricarboxílico). Na primeira etapa do trabalho foi investigado o efeito da rota sintética e os parâmetros de síntese na formação das partículas nanométricas do material. As análises de fisissorção de N2 revelaram a natureza micro/mesoporoso da MIL-100(Fe) com diâmetros de poro entre 1,5 e 2,5 nm e área específica extremamente elevada (~ 1.500 m2 g -1 ) e meso/macroporoso da BMMg-2 com diâmetros de poro entre 25 e 55 nm e área específica (~ 46,382 m2 g -1 ). Em seguida, foi realizado o ensaio de encapsulamento do antibiótico estreptomicina nos poros da matriz MOF MIL100(Fe), tendo sido obtido o compósito MIL-100(Fe)@Estrep.. Os resultados do material compósito apresentaram potencial para atuarem como um sistema promissor no combate microbiano, posto que a avaliação da atividade antimicrobiana frente à Staphylococcus aureus e Escherichia coli demonstrou resultados eficientes para as cepas Gram-positiva e Gram-negativa, respectivamente.
Over the past few decades, resistance to antimicrobials has been an important object of study. The indiscriminate use of antibiotics leads to the selection of resistant bacterial strains and, with this, researchers are looking for more efficient strategies in the eradication of microorganisms. Within this perspective, as metalorganic networks (or MOFs, Metal-Organic Fameworks) can be an alternative. It is a subclass of coordination polymers with an open structure containing potentially available cavities (pores). Due to their intrinsic properties such as high specific area, crystallinity, thermal stability, permanent porosity, among others, MOFs have a potential application in several areas such as gas storage and separation, heterogeneous catalysis, drug delivery, chemical sensors, among others. Thus, the main objective of this work is the nanoscale synthesis of a biocompatible MOF structure (BMMg and MIL-100 (Fe)), the characterization, the incorporation of the streptomycin antibiotic (Estrep.) and the evaluation of the antibacterial activity of MIL-100(Fe)@Estrep.. The BMMg structure was obtained from the precursors magnesium chloride, terephthalic acid and adenine in different proportions by the solvothermal method and MIL-100 (Fe) by the microwave assisted method, from the mixture of iron (III) chloride and the trimesic acid (1,3,5-benzene tricarboxylic). In the first stage of the work, the effect of the synthetic route and the synthesis parameters on the formation of the nanometric particles of the material were investigated. The analysis of N2 physisorption revealed the micro/mesoporous nature of MIL-100(Fe) with pore diameters between 1.5 and 2.5 nm and an extremely high specific area (~ 1,500 m2 .g -1 ) and meso/macroporous of BMMg-2 with pore diameters between 25 and 55 nm and specific area (~ 46,382 m2 .g -1 ). Then, the encapsulation test of the antibiotic streptomycin was carried out in the pores of the MOF MIL-100(Fe) matrix, and the MIL-100(Fe)@Estrep. composite was obtained. The results of the composite material showed potential to act as a promising system in the microbial combat, since the evaluation of the antimicrobial activity against Staphylococcus aureus and Escherichia coli demonstrated efficient results for the Gram-positive and Gram-negative strains, respectively.
Over the past few decades, resistance to antimicrobials has been an important object of study. The indiscriminate use of antibiotics leads to the selection of resistant bacterial strains and, with this, researchers are looking for more efficient strategies in the eradication of microorganisms. Within this perspective, as metalorganic networks (or MOFs, Metal-Organic Fameworks) can be an alternative. It is a subclass of coordination polymers with an open structure containing potentially available cavities (pores). Due to their intrinsic properties such as high specific area, crystallinity, thermal stability, permanent porosity, among others, MOFs have a potential application in several areas such as gas storage and separation, heterogeneous catalysis, drug delivery, chemical sensors, among others. Thus, the main objective of this work is the nanoscale synthesis of a biocompatible MOF structure (BMMg and MIL-100 (Fe)), the characterization, the incorporation of the streptomycin antibiotic (Estrep.) and the evaluation of the antibacterial activity of MIL-100(Fe)@Estrep.. The BMMg structure was obtained from the precursors magnesium chloride, terephthalic acid and adenine in different proportions by the solvothermal method and MIL-100 (Fe) by the microwave assisted method, from the mixture of iron (III) chloride and the trimesic acid (1,3,5-benzene tricarboxylic). In the first stage of the work, the effect of the synthetic route and the synthesis parameters on the formation of the nanometric particles of the material were investigated. The analysis of N2 physisorption revealed the micro/mesoporous nature of MIL-100(Fe) with pore diameters between 1.5 and 2.5 nm and an extremely high specific area (~ 1,500 m2 .g -1 ) and meso/macroporous of BMMg-2 with pore diameters between 25 and 55 nm and specific area (~ 46,382 m2 .g -1 ). Then, the encapsulation test of the antibiotic streptomycin was carried out in the pores of the MOF MIL-100(Fe) matrix, and the MIL-100(Fe)@Estrep. composite was obtained. The results of the composite material showed potential to act as a promising system in the microbial combat, since the evaluation of the antimicrobial activity against Staphylococcus aureus and Escherichia coli demonstrated efficient results for the Gram-positive and Gram-negative strains, respectively.
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Materiais porosos, Íons complexos, Biocompatibilidade, Ferro, Fármacos, Porous materials, Complex ions, Biocompatibility, Iron, Drugs