"Avaliação do potencial de filmes de alginato de sódio contendo curcumina encapsulada em nanopartículas de quitosana associados à terapia fotodinâmica para o tratamento de biofilmes orais."
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Data
2020-11-27
Autores
Silvestre, Amanda Letícia Polli
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
A cavidade oral é colonizada por várias espécies de microrganismos, dentre eles Streptococcus mutans e Candida albicans são os mais predominantes e podem ser encontrados organizados na forma de biofilme, podendo causar cáries e candidíase bucal. O tratamento convencional para remoção desses biofilmes orais consiste na sua remoção mecânica associada à administração sistêmica de antimicrobianos, que causa vários efeitos colaterais ao paciente, além de ser potencial causador de resistência microbiana. Diante desse contexto, terapias alternativas têm sido desenvolvidas para o tratamento de doenças na cavidade oral, dentre elas a Terapia Fotodinâmica Antimicrobiana (aTFD), que é realizada com a utilização de um fotossensibilizador, como a curcumina (CUR). No entanto, a CUR apresenta a limitação de ser um composto de baixa solubilidade aquosa e que sofre degradação quando exposto à luz, temperatura e condições alcalina. Uma estratégia para suprir essas limitações é sua incorporação em nanopartículas poliméricas (NPs), que oferecem importantes benefícios, como melhoria da solubilidade e proteção contra a degradação. A incorporação de NPs_CUR em filmes de alginato de sódio (FA) contribui para adesão do sistema na cavidade oral, otimizando a aplicação da aTFD e a ação antimicrobiana. O presente trabalho teve como objetivo a avaliação do potencial de FA contendo CUR encapsulada em NPs de quitosana (QTS) e alginato de sódio (ALG) associados à aTFD para o tratamento de biofilmes orais. As NPs foram obtidas pelo método de complexação polieletrolítica através da concentração de 0,3 mg/mL de QTS e 0,5 mg/mL de ALG com proporções (m/m) de 0,05:1 até 1:1 e foram caracterizadas empregando análise de diâmetro hidrodinâmico médio (DHM), índice de polidispersão (IPD), potencial zeta (PZ), microscopia eletrônica de varredura (MEV), eficiência de encapsulação (EE) e análise térmica. Os FAs foram obtidos pelo método de evaporação do solvente utilizando 2% de ALG e 10% de glicerina e foram caracterizados por ensaios de absorção de líquidos, determinação da espessura, permeabilidade ao vapor de água (PVA), propriedades mecânicas e mucoadesão. Realizou-se ensaio de liberação in vitro do sistema final FA/NPs_CUR, CUR livre e NPs_CUR. Foram ainda determinadas a concentração inibitória mínima (CIM) e bactericida (CBM) frente ao S. mutans, avaliou-se o efeito fotodinâmico sobre os biofilmes de S. mutans e C. albicans e a contagem de Unidades Formadoras de Colônias (UFC/mL). As NPs foram obtidas com sucesso obtendo-se resultados adequados para todas as proporções testadas, principalmente para amostra 0,30:1com DHM de181,6 nm, IPD de 0,23 e PZ de - 30,6 mV. As fotomicrografias obtidas por MEV evidenciaram morfologia esférica das NPs. A incorporação da CUR manteve a NP esférica e com tamanho entre 200 e 300 nm, indicando que houve incorporação e isso pode ser afirmado pela EE, a qual obteve o valor de 32,91 a 80,23%. Os FA foram obtidos com sucesso e mostraram-se homogêneos, sem fissuras ou bolhas e com adequadas propriedades mecânicas e de espessura, além de apresentarem PVA e absorção de líquidos considerável e excelentes propriedades mucoadesivas. O ensaio de liberação in vitro indicou que a liberação foi controlada por difusão e intumescimento, com 92,31% de CUR liberada após 24 h a partir das FA/NPs_CUR, 47,77% para CUR livre e 50,79% para NP_CUR. No ensaio microbiológico de CIM e CBM obteve-se para CUR livre um valor de 2,175 µg/mL e para NPs-CUR de 8,7 µg/mL. Os resultados de UFC/mL nos ensaios de biofilme de C. albicans não demostraram redução significativas de log entre os grupos testados com os tratamentos com luz e sem luz. Por outro lado, os ensaios de UFC/mL para o biofilme de S. mutans demostraram redução de 3 log10 para o grupo das NPs testadas quando comparadas com os tratamentos sem luz. Portanto, os resultados são promissores e sugerem que o sistema desenvolvido apresenta potencial para o tratamento de biofilme de S.mutans.
The oral cavity is colonized by several species of microorganisms, among them, Streptococcus mutans and Candida albicans are the most prevalent and can be found organized in the form of biofilm, which can cause cavities and oral candidiasis. The conventional treatment for the removal of these oral biofilms consists of their mechanical removal associated with the systemic administration of antimicrobials, which causes several side effects to the patient, in addition to being a potential cause of microbial resistance. In this context, alternative therapies have been developed to treat diseases in the oral cavity, including Antimicrobial Photodynamic Therapy (aPDT), which is performed using a photosensitizer, such as curcumin (CUR). However, CUR has the limitation of being a hydrophobic compound and that suffers degradation in light, temperature, and alkaline conditions. One strategy to overcome these limitations is their incorporation into polymeric nanoparticles (NPs), which offer important benefits, such as improved solubility and protection against degradation. The incorporation of NPs_CUR in sodium alginate films (FA) contributes to system adhesion in the oral cavity, optimizing the application of aPDT and the antimicrobial action. This work aims to evaluate the potential of FA containing CUR encapsulated in NPs of chitosan (CS) and sodium alginate (SA) associated with aPDT for the treatment of oral biofilms. The NPs were obtained by the polyelectrolytic complexation method through the concentration of 0.3 mg / mL of QTS and 0.5 mg / mL of ALG with proportions (w/w) of 0.05:1 to 1:1 and were characterized employing the analysis of average hydrodynamic diameter (DHM), polydispersion index (PDI), zeta potential (ZP), scanning electron microscopy (SEM), encapsulation efficiency (EE) and thermal analysis. The FAs were obtained by the solvent casting method using 2% SA and 10% glycerin and were characterized by liquid absorption tests, thickness determination, water vapor permeability (PVA), mechanical properties, and mucoadhesion. An in vitro release test of the final system FA/NPs_CUR, free CUR, and NPs_CUR was performed. The minimum inhibitory (MIC) and bactericidal (CBM) concentrations against S. mutans were also determined and the photodynamic effect on the biofilms of S. mutans and C. albicans and the count of Colony Forming Units (CFU/mL) were evaluated. The NPs were successfully obtained, obtaining adequate results for all the proportions tested, mainly for 0.30: 1 sample with DHM of 181.6 nm, PDI of 0.23, and ZP of - 30.6 mV. The photomicrographs obtained by SEM showed the spherical morphology of the NPs. The incorporation of CUR kept the spherical NP with a size between 200 and 300 nm indicating that there was incorporation, and this can be affirmed by EE where it obtained the value of 32.91 to 80.23%. The FA were successfully obtained and proved to be homogeneous without fissures or bubbles and adequate mechanical and thickness properties, in addition to having PVA and considerable liquid absorption and excellent mucoadhesive properties. The in vitro release test indicates that the release is controlled by diffusion and swelling using the Korsmeyer Peppas model, with a 24-hour release profile of 92.31% for FA/NPs_CUR, 47.77% for free CUR, and 50.79 % for NP_CUR. In the MIC and CBM microbiological assay, a value of 2,175 µg / mL was obtained for free CUR and 8,7 µg / mL for NPs-CUR. The results of CFU / mL in the biofilm assays of C. albicans did not show significant log reduction between the groups tested with treatments with and without light. On the other hand, the UFC / mL assays for the S. mutans biofilm showed a reduction of 3 log10 for the group of tested NPs when compared to treatments without light. Therefore, the results are promising and suggest that the developed system has the potential for the treatment of S. mutans biofilms.
The oral cavity is colonized by several species of microorganisms, among them, Streptococcus mutans and Candida albicans are the most prevalent and can be found organized in the form of biofilm, which can cause cavities and oral candidiasis. The conventional treatment for the removal of these oral biofilms consists of their mechanical removal associated with the systemic administration of antimicrobials, which causes several side effects to the patient, in addition to being a potential cause of microbial resistance. In this context, alternative therapies have been developed to treat diseases in the oral cavity, including Antimicrobial Photodynamic Therapy (aPDT), which is performed using a photosensitizer, such as curcumin (CUR). However, CUR has the limitation of being a hydrophobic compound and that suffers degradation in light, temperature, and alkaline conditions. One strategy to overcome these limitations is their incorporation into polymeric nanoparticles (NPs), which offer important benefits, such as improved solubility and protection against degradation. The incorporation of NPs_CUR in sodium alginate films (FA) contributes to system adhesion in the oral cavity, optimizing the application of aPDT and the antimicrobial action. This work aims to evaluate the potential of FA containing CUR encapsulated in NPs of chitosan (CS) and sodium alginate (SA) associated with aPDT for the treatment of oral biofilms. The NPs were obtained by the polyelectrolytic complexation method through the concentration of 0.3 mg / mL of QTS and 0.5 mg / mL of ALG with proportions (w/w) of 0.05:1 to 1:1 and were characterized employing the analysis of average hydrodynamic diameter (DHM), polydispersion index (PDI), zeta potential (ZP), scanning electron microscopy (SEM), encapsulation efficiency (EE) and thermal analysis. The FAs were obtained by the solvent casting method using 2% SA and 10% glycerin and were characterized by liquid absorption tests, thickness determination, water vapor permeability (PVA), mechanical properties, and mucoadhesion. An in vitro release test of the final system FA/NPs_CUR, free CUR, and NPs_CUR was performed. The minimum inhibitory (MIC) and bactericidal (CBM) concentrations against S. mutans were also determined and the photodynamic effect on the biofilms of S. mutans and C. albicans and the count of Colony Forming Units (CFU/mL) were evaluated. The NPs were successfully obtained, obtaining adequate results for all the proportions tested, mainly for 0.30: 1 sample with DHM of 181.6 nm, PDI of 0.23, and ZP of - 30.6 mV. The photomicrographs obtained by SEM showed the spherical morphology of the NPs. The incorporation of CUR kept the spherical NP with a size between 200 and 300 nm indicating that there was incorporation, and this can be affirmed by EE where it obtained the value of 32.91 to 80.23%. The FA were successfully obtained and proved to be homogeneous without fissures or bubbles and adequate mechanical and thickness properties, in addition to having PVA and considerable liquid absorption and excellent mucoadhesive properties. The in vitro release test indicates that the release is controlled by diffusion and swelling using the Korsmeyer Peppas model, with a 24-hour release profile of 92.31% for FA/NPs_CUR, 47.77% for free CUR, and 50.79 % for NP_CUR. In the MIC and CBM microbiological assay, a value of 2,175 µg / mL was obtained for free CUR and 8,7 µg / mL for NPs-CUR. The results of CFU / mL in the biofilm assays of C. albicans did not show significant log reduction between the groups tested with treatments with and without light. On the other hand, the UFC / mL assays for the S. mutans biofilm showed a reduction of 3 log10 for the group of tested NPs when compared to treatments without light. Therefore, the results are promising and suggest that the developed system has the potential for the treatment of S. mutans biofilms.
Descrição
Palavras-chave
Nanotecnologia Farmacêutica, Nanopartículas Poliméricas, Filmes bucais, Curcumina, Quitosana, Alginato de sódio, Biofilmes orais, Terapia fotodinâmica