Departamento de Química Física, Facultad de Ciencias Ambientales y Bioquímica, and INAMOL, Universidad de Castilla-La Mancha, Toledo, Spain.
Langmuir. 2012 May 1;28(17):6746-59. doi: 10.1021/la2049713. Epub 2012 Mar 21.
In this feature article, we discuss recent advances in studying ultrafast dynamic and structural aspects of host-guest interactions. Steady-state and time-resolved techniques exploring events from the femto- to nanosecond regime were used to examine the ultrafast photodynamics and subsequent events in selected nanostructures of the formed complexes. These consist of aromatic systems, biologically relevant molecules, and drugs trapped within cyclodextrins (CD) and human serum albumin (HSA) protein pockets. We examine the effects exerted by these chemical and biological cavitands on internal twisting motions, proton transfer and charge transfer, and cis-trans isomerization reactions that may occur in the confined molecular systems. In addition, the influence of a restricting environment on the interaction of guest molecules with biological water is considered. The dynamic details of the complexes (diffusion, early interactions, formation, stability, internal guest diffusion, and conformational changes) and the excited-state relaxation pathways, rate constants of the involved processes, and changes in the electronic distribution within encapsulated guests gave clues to elucidate their photobehavior and are relevant to the photostability and delivery of drugs when using nanocarriers.
在这篇专题文章中，我们讨论了研究主体-客体相互作用超快动力学和结构方面的最新进展。使用稳态和时间分辨技术从飞秒到纳秒的时间范围内探索事件，以检查形成的复合物的选定纳米结构中的超快光动力学和后续事件。这些复合物包括芳族体系、生物相关分子以及被困在环糊精 (CD) 和人血清白蛋白 (HSA) 蛋白口袋中的药物。我们研究了这些化学和生物空穴对内部扭转运动、质子转移和电荷转移以及顺反异构反应的影响，这些反应可能发生在受限的分子系统中。此外，还考虑了限制环境对客体分子与生物水相互作用的影响。复合物的动态细节（扩散、早期相互作用、形成、稳定性、内部客体扩散和构象变化）以及激发态弛豫途径、涉及过程的速率常数以及封装客体内部电子分布的变化为阐明其光致行为提供了线索，并且与使用纳米载体时药物的光稳定性和输送有关。
