Síntese e avaliação do efeito antibiofilme de um novo nanosistema composto por nanopartículas magnéticas de óxido de ferro, quitosana e clorexidina
Data
2018-02-23
Autores
Vieira, Ana Paula Miranda [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Objetivo: Este estudo sintetizou um novo nanosistema carreador de clorexidina (CLX) baseado em nanopartículas magnéticas de óxido de ferro (NMOFs) e quitosana (QS), e avaliou seu efeito antimicrobiano sobre biofilmes de Candida albicans e Streptococcus mutans: Metodologia: O nanosistema NMOFs-QS-CLX foi preparado pela interação de CLX sobre NMOFs revestidas com QS, e caracterizado por difração de raios X, espectroscopia de absorção na região do infravermelho médio com transformada de Fourier, microscopia eletrônica de transmissão e dispersão dinâmica de luz. A concentração inibitória mínima (CIM) do nanosistema NMOFs-QS-CLX capaz de inibir as cepas no estado planctônico foi determinada de acordo com o método de microdiluição em caldo. Na sequência, biofilmes simples e mistos de C. albicans e S. mutans foram formados durante 24 horas em poços de placas de 96 poços na presença do nanosistema contendo CLX a 39 (NMOFs-QS-CLX39) ou 78 μg/mL (NMOFs-QS-CLX78). Ainda, biofilmes pré-formados (24 horas) foram tratados durante 24 horas com o nanosistema nas mesmas concentrações. O efeito antibiofilme foi avaliado através da contagem do número de células cultiváveis, quantificação da biomassa total e avaliação da atividade metabólica. Controles apropriados foram incluídos em todas as análises. Os dados foram analisados pelo teste de Kruskal-Wallis e por ANOVA a um critério, seguidos dos testes Student-Newman-Keuls e Holm-Sidak, respectivamente (α = 0,05). Resultados: Os resultados de caracterização confirmaram a formação do nanosistema NMOFs-QS-CLX, sem alteração das propriedades cristalinas das NMOFs. Além disso, as bandas de absorção características de cada composto foram identificadas no espectro do infravermelho, e o diâmetro médio do nanosistema foi menor que 40 nm. Os resultados de CIM mostraram que o nanosistema foi ligeiramente mais efetivo do que a CLX na inibição do crescimento dos microrganismos testados. Biofilmes formados na presença do nanosistema NMOFs-QS-CLX39 atingiram patamares quantitativos similares àqueles observados para CLX a 78 µg/mL. Ainda, para os biofilmes simples e mistos, o nanosistema NMOFs-QS-CLX78 mostrou efeitos redutores superiores ou similares àqueles encontrados para CLX a 78 µg/mL e NMOFs-QS-CLX39. Conclusão: O nanosistema NMOFs-QS-CLX foi efetivo tanto na inibição da formação de biofilmes como sobre biofilmes pré-formados de C. albicans e S. mutans em culturas simples ou mistas. O desenvolvimento desse nanosistema instaura inúmeras possibilidades para exploração de terapias baseadas em nanopartículas magnéticas como carreadoras de drogas usadas na área médico-odontológica.
Aim: This study synthesized a new chlorhexidine(CHX)-carrier nanosystem based on iron oxide magnetic nanoparticles (IONPs) and chitosan (CS), as well as evaluated its antimicrobial effect on biofilms of Candida albicans and Streptococcus mutans. Method: The IONPs-CS-CHX nanosystem was prepared by CHX interaction to CS-coated IONPs and characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. Minimum inhibitory concentration (MIC) of the IONPs-CS-CHX nanosystem was determined according to the broth microdilution assay. After, mono- and dual-species biofilms of C. albicans and S. mutans were formed for 24 hours into wells of 96-well plates in the presence of the nanosystem containing CHX at 39 (IONPs-CS-CHX39) or 78 μg/mL (IONPs-CS-CHX78). Moreover, pre-formed biofilms (24 h) were treated for 24 h with the nanosystem at the same concentrations. The antibiofilm effect was determined by quantification of cultivable cells, total biomass and metabolic activity. Appropriate controls were included in all analyzes. Data were analyzed by Kruskal-Wallis’ test and one-way ANOVA, followed by Student-Newman-Keuls and Holm-Sidak tests (α = 0.05). Results: Characterization results confirmed the nanosystem formation without altering the crystalline properties of the IONPs. In addition, the characteristic absorption bands of each compound were identified in the infrared spectrum, and the mean diameter of the nanosystem was lower than 40 nm. MIC results showed that the nanosystem was slightly more effective than CLX in inhibiting the growth of the microorganisms tested. Biofilms formed in the presence of IONPs-CS-CHX39 attained similar quantitative levels to those observed for CHX at 78 μg/mL. Further, for mono- and dual-species biofilms, IONPs-CS-CHX78 showed similar or superior antibiofilm effects when compared with IONPs-CS-CHX39 and free CHX at 78 μg/mL. Conclusion: The IONPs-CS-CHX nanosystem was able to reduce biofilm formation and pre-formed biofilms of C. albicans and S. mutans in single or mixed cultures. The development of this nanosystem establishes several possibilities for exploration of magnetic nanoparticle-based therapy as drug carrier used in health area.
Aim: This study synthesized a new chlorhexidine(CHX)-carrier nanosystem based on iron oxide magnetic nanoparticles (IONPs) and chitosan (CS), as well as evaluated its antimicrobial effect on biofilms of Candida albicans and Streptococcus mutans. Method: The IONPs-CS-CHX nanosystem was prepared by CHX interaction to CS-coated IONPs and characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. Minimum inhibitory concentration (MIC) of the IONPs-CS-CHX nanosystem was determined according to the broth microdilution assay. After, mono- and dual-species biofilms of C. albicans and S. mutans were formed for 24 hours into wells of 96-well plates in the presence of the nanosystem containing CHX at 39 (IONPs-CS-CHX39) or 78 μg/mL (IONPs-CS-CHX78). Moreover, pre-formed biofilms (24 h) were treated for 24 h with the nanosystem at the same concentrations. The antibiofilm effect was determined by quantification of cultivable cells, total biomass and metabolic activity. Appropriate controls were included in all analyzes. Data were analyzed by Kruskal-Wallis’ test and one-way ANOVA, followed by Student-Newman-Keuls and Holm-Sidak tests (α = 0.05). Results: Characterization results confirmed the nanosystem formation without altering the crystalline properties of the IONPs. In addition, the characteristic absorption bands of each compound were identified in the infrared spectrum, and the mean diameter of the nanosystem was lower than 40 nm. MIC results showed that the nanosystem was slightly more effective than CLX in inhibiting the growth of the microorganisms tested. Biofilms formed in the presence of IONPs-CS-CHX39 attained similar quantitative levels to those observed for CHX at 78 μg/mL. Further, for mono- and dual-species biofilms, IONPs-CS-CHX78 showed similar or superior antibiofilm effects when compared with IONPs-CS-CHX39 and free CHX at 78 μg/mL. Conclusion: The IONPs-CS-CHX nanosystem was able to reduce biofilm formation and pre-formed biofilms of C. albicans and S. mutans in single or mixed cultures. The development of this nanosystem establishes several possibilities for exploration of magnetic nanoparticle-based therapy as drug carrier used in health area.
Descrição
Palavras-chave
Clorexidina, Nanopartículas, Candida albicans, Streptococcus mutans, Chlorhexidine