Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Departamento de Química, Brazil.
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Brazil.
Colloids Surf B Biointerfaces. 2019 Sep 1;181:856-863. doi: 10.1016/j.colsurfb.2019.06.039. Epub 2019 Jun 18.
Flavonoid-metal complexes are widely studied because of their interesting luminescent behavior and biological activity. Despite the extensive exploration of flavonoid-metal coordination processes in solution, the formation of complexes using the flavonoid molecule inserted in a lipid membrane has been little investigated. This effect could provide important insight into the biological activity of flavonoids at lipid membranes and could represent an attractive strategy to design supramolecular structures. Here, we studied the complexation between Sr and morin inserted in an octadecylphosphonic acid (OPA) Langmuir monolayer. This is a relevant system due to the synergism imposed by the association of the Sr ability to control bone formation/resorption with the morin antioxidative effect. Morin incorporation into the OPA monolayers and further Sr complexation were monitored by surface pressure isotherms. Electronic absorption spectroscopy and fluorescence techniques showed Sr-morin complexation both in solution and at the air-liquid interface. Although morin complexation has been described to occur only at basic pH, the specific thermodynamic properties at the air-liquid interface drove metal complexation. LB films were deposited on Ti surfaces, and the resulting OPA/Sr-morin coatings exhibited high surface free energy and increase on its polar component. This optimized surface feature supported further serum protein adsorption and osteoblast growth and differentiation, indicating that these lipid-based coatings are promising for bioactive coating design. This study paves the way for the use of this lipid-based coating in the design of implants for faster osteointegration. Moreover, flavonoid-metal complexation at membranes could also help to shed light on the biological role played by flavonoids.
黄酮类金属配合物因其有趣的发光行为和生物活性而受到广泛研究。尽管人们广泛探索了黄酮类金属配位过程在溶液中的情况，但在脂质膜中插入黄酮类分子形成配合物的情况却很少被研究。这种效应可以为黄酮类物质在脂质膜中的生物活性提供重要的见解，并可能代表一种有吸引力的设计超分子结构的策略。在这里，我们研究了 Sr 和插入十八烷磷酸（OPA）Langmuir 单层中的桑色素之间的配合物。由于 Sr 控制骨形成/吸收的能力与桑色素抗氧化作用的协同作用，该系统是一个相关的系统。通过表面压力等温线监测了 OPA 单层中 morin 的掺入以及随后的 Sr 络合。电子吸收光谱和荧光技术表明，Sr-桑色素络合物既存在于溶液中，也存在于气液界面上。尽管已经描述了 morin 络合仅在碱性 pH 下发生，但气液界面的特定热力学特性促使金属络合。LB 膜沉积在 Ti 表面上，所得的 OPA/Sr-桑色素涂层表现出高表面自由能和其极性分量的增加。这种优化的表面特性支持进一步的血清蛋白吸附和成骨细胞的生长和分化，表明这些基于脂质的涂层在生物活性涂层设计方面具有广阔的应用前景。本研究为在设计用于更快骨整合的植入物中使用这种基于脂质的涂层铺平了道路。此外，膜上的黄酮类金属络合也有助于阐明黄酮类物质在生物中的作用。
