Pulido-Reyes Gerardo, Martín Esperanza, Gu Coronado J L, Leganes Francisco, Rosal Roberto, Fernández-Piñas Francisca
Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049, Spain; Departamento de Ingeniería Química, Universidad de Alcalá, E-28871 Alcalá de Henares, Madrid, Spain.
Departamento de Química-Física Aplicada, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049, Spain.
J Photochem Photobiol B. 2017 Jul;172:61-69. doi: 10.1016/j.jphotobiol.2017.05.009. Epub 2017 May 10.
Cerium (Ce) oxide nanoparticles (CNPs) have attracted attention due to their high bioactivity and unique redox-chemistry. The oxygen vacancies at the surface of the nanoparticle explain the autocatalytic properties of CNPs in which the Ce atoms occupy the center of the oxygen vacancies surrounded by Ce atoms. Until now, CNPs have been associated with organic molecules at the synthesis stage to extend their applications or improve their stability. However, there is a lack of information regarding the post-synthesis interaction of CNPs and organic molecules that could enhance or induce new properties. Due to their unique optical properties and their many uses in different areas such as supramolecular chemistry or biomedicine, we have chosen a derivative from the family of naphthalimides (the 4-amino-1,8-naphthalimide-N-substituted; ANN) to study the interaction with different CNPs (CNP1-4) and their joint bioactivity compared to that of the same compounds alone. ANN-CNP complexes were formed as revealed by spectroscopic studies, but, the interaction was markedly different depending on the physicochemical properties of CNPs and their surface content of Ce sites. The ANN adsorption on all CNPs involved the amino group in the naphthalene moiety as shown by NMR spectroscopy, while the pyrrolidine ring was mainly involved in the specific interaction between ANN and CNP1. The biological effect of each CNP and ANN individually and forming complexes was assessed using a bioluminescent model bacterium. The results showed that ANN and CNP with the higher content of surface Ce (CNP1) when combined acted additively towards the used model organism. In the opposite, ANN-CNP2, ANN-CNP3 and ANN-CNP4 complexes were antagonistic when the nanoparticles dominated the mixture. The results of this study contribute to expand the knowledge of the interaction between nanoparticles and organic molecules which may be useful for understanding the behavior of nanoparticles in complex matrices.
氧化铈（Ce）纳米颗粒（CNPs）因其高生物活性和独特的氧化还原化学性质而备受关注。纳米颗粒表面的氧空位解释了CNPs的自催化特性，其中Ce原子占据被Ce原子包围的氧空位中心。到目前为止，CNPs在合成阶段已与有机分子结合以扩展其应用或提高其稳定性。然而，关于CNPs与有机分子合成后相互作用的信息匮乏，而这种相互作用可能会增强或诱导新的性质。由于其独特的光学性质以及在超分子化学或生物医学等不同领域的多种用途，我们选择了萘二甲酰亚胺家族的一种衍生物（4-氨基-1,8-萘二甲酰亚胺-N-取代物；ANN）来研究其与不同CNPs（CNP1-4）的相互作用以及与单独相同化合物相比它们的联合生物活性。光谱研究表明形成了ANN-CNP复合物，但相互作用明显不同，这取决于CNPs的物理化学性质及其Ce位点的表面含量。核磁共振光谱显示，ANN在所有CNPs上的吸附都涉及萘部分的氨基，而吡咯烷环主要参与ANN与CNP1之间的特异性相互作用。使用生物发光模型细菌评估了每种CNP和ANN单独以及形成复合物后的生物学效应。结果表明，表面Ce含量较高的ANN和CNP（CNP1）组合时对所用模型生物具有相加作用。相反，当纳米颗粒在混合物中占主导时，ANN-CNP2、ANN-CNP3和ANN-CNP4复合物具有拮抗作用。这项研究的结果有助于扩展对纳米颗粒与有机分子之间相互作用的认识，这可能有助于理解纳米颗粒在复杂基质中的行为。
