LADEG, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Bioinovar - Biotechnology Laboratories: Biocatalysis, Bioproducts and Bioenergy, Institute of Microbiology Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
J Photochem Photobiol B. 2020 Oct;211:112010. doi: 10.1016/j.jphotobiol.2020.112010. Epub 2020 Aug 28.
Nanotechnology, when applied to PDT's, allows the encapsulation of ZnPc in nanocarriers, producing thus nanoemulsions that permit the use of ZnPc as photosensitizers. The Enterococcus faecalis and methicillin-resistant Staphylococcus aureus (MRSA) are microorganisms present in biofilms which can cause resistant endodontic infections. The objective of this work is the development and characterization of clove essential oil nanoemulsions containing ZnPc. The formulations were developed according to factorial experimental planning and characterized by the determination of the mean drop size, Polydispersity Index (PdI), content, organoleptic characteristics, stability, morphology, cytotoxicity in the dark and evaluation of the photobiological activity. The experimental planning was able to indicate the maximum amount of ZnPc that could be encapsulated in the nanoemulsion while maintaining droplet size <50 nm and PdI < 0.2. The surface plots for the response variables indicated a robust region for the combination of Pluronic® F-127 and clove oil factors. The result of this study was the choice of the nanoemulsion containing ZnPc solution at 5%, clove oil at 5%, Pluronic® F-127 at 10% and will be codified as ZnPc-NE. The nanoemulsion presented a mean diameter of 30.52 nm, PDI < 0.2 and a concentration of 17.5 μg/mL, as well as stability at room temperature for 180 days. TEM showed that the drops are spherical with nanometric size, which corroborates the results of dynamic light scattering. Concerning the photobiological activity, the ZnPc-NE exhibited MIC 1.09 μg/mL for Enterococcus faecalis and 0.065 μg/mL for MRSA (Methicillin-resistant Staphylococcus aureus). ZnPc-NE showed higher photobiological activity than free ZnPc. Besides, cytotoxicity studies showed that blank-NE (nanoemulsions without PS) showed good antimicrobial activity. Thus, clove oil nanoemulsion is an excellent nanocarrier to promote the photobiological activity of the ZnPc against pathogenic microorganisms.
纳米技术在 PDT 中的应用允许将 ZnPc 封装在纳米载体中，从而产生允许使用 ZnPc 作为光敏剂的纳米乳剂。粪肠球菌和耐甲氧西林金黄色葡萄球菌（MRSA）是生物膜中存在的微生物，可引起耐药性根管感染。这项工作的目的是开发和表征含有 ZnPc 的丁香精油纳米乳剂。制剂是根据析因实验设计开发的，并通过测定平均液滴尺寸、多分散指数（PdI）、含量、感官特性、稳定性、形态、黑暗中的细胞毒性以及光生物活性评价来进行表征。实验设计能够指示可以在保持<50nm 液滴尺寸和 PdI<0.2 的情况下封装在纳米乳剂中的最大 ZnPc 量。响应变量的表面图表明，Pluronic® F-127 和丁香油因子的组合具有强大的区域。该研究的结果是选择含有 5%ZnPc 溶液、5%丁香油、10%Pluronic® F-127 的纳米乳剂，并将其编码为 ZnPc-NE。纳米乳剂的平均直径为 30.52nm，PDI<0.2，浓度为 17.5μg/mL，在室温下稳定 180 天。TEM 显示，液滴呈球形，具有纳米级尺寸，这与动态光散射的结果相符。关于光生物活性，ZnPc-NE 对粪肠球菌的 MIC 为 1.09μg/mL，对耐甲氧西林金黄色葡萄球菌（MRSA）的 MIC 为 0.065μg/mL。ZnPc-NE 表现出比游离 ZnPc 更高的光生物活性。此外，细胞毒性研究表明，空白-NE（不含 PS 的纳米乳剂）表现出良好的抗菌活性。因此，丁香精油纳米乳剂是一种极好的纳米载体，可提高 ZnPc 对致病微生物的光生物活性。
