Rani Swati, Bagchi Damayanti, Pal Uttam, Kumari Mamta, Sharma Manisha, Bera Arpan, Shabir Javaid, Pal Samir Kumar, Saha-Dasgupta Tanusri, Mozumdar Subho
Department of Chemistry, University of Delhi, Delhi 110007, India.
Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, West Bengal 700106, India.
ACS Omega. 2020 Oct 1;5(40):25582-25592. doi: 10.1021/acsomega.0c02438. eCollection 2020 Oct 13.
The naturally occurring polyphenolic compound curcumin has shown various medicinal and therapeutic effects. However, there are various challenges associated with curcumin, which limits its biomedical applications, such as its high degradation rate and low aqueous solubility at neutral and alkaline pH. In the present study, efforts have been directed towards trying to resolve such issues by encapsulating curcumin inside the micelles formed by imidazolium-based surface-active ionic liquid (SAIL). The shape and size of the micelles formed by the SAIL have been characterized by using DLS analysis as well as TEM measurements. The photo-physics of curcumin in the presence of ionic liquid (IL) and also with the addition of salt (NaCl) has been explored by using different optical spectroscopic tools. The time-dependent absorption studies have shown that there is relatively higher suppression in the degradation rate of curcumin after encapsulation by the imidazolium-based SAIL in an aqueous medium. The TCSPC studies have revealed that there is deactivation in the nonradiative intramolecular hydrogen transfer process of curcumin in the presence of IL micelles as well as with the addition of salt. Furthermore, the time-dependent fluorescence anisotropy measurement has been carried out to figure out the location of curcumin inside the micellar system. In order to correlate all experimental findings, density functional theory (DFT) and classical molecular dynamics (MD) simulations at neutral pH media have been performed. It has been found that the van der Waals force of interactions plays a major role in the stabilization of curcumin in the micelles rather than the coulombic forces. It also has been observed that the van der Waals interactions remain unaffected in the presence of salt. However, as revealed by the MD simulation results, the micelles are found to be more compact in size after the addition of salt. The RMSD results show that the micelles formed by the SAIL achieve greater stability after a particular time constraint. Our results have divulged that the SAIL could act as a promising drug delivery system.
天然存在的多酚类化合物姜黄素已显示出多种药用和治疗效果。然而，姜黄素存在各种相关挑战，这限制了其生物医学应用，例如其高降解率以及在中性和碱性pH下的低水溶性。在本研究中，已致力于通过将姜黄素封装在基于咪唑鎓的表面活性离子液体（SAIL）形成的胶束中来解决此类问题。通过动态光散射（DLS）分析以及透射电子显微镜（TEM）测量对SAIL形成的胶束的形状和大小进行了表征。利用不同的光学光谱工具研究了离子液体（IL）存在下以及添加盐（NaCl）后姜黄素的光物理性质。时间相关吸收研究表明，在水性介质中，基于咪唑鎓的SAIL封装后姜黄素的降解率受到相对较高的抑制。时间相关单光子计数（TCSPC）研究表明，在IL胶束存在下以及添加盐后，姜黄素的非辐射分子内氢转移过程发生失活。此外，进行了时间相关荧光各向异性测量以确定姜黄素在胶束系统中的位置。为了关联所有实验结果，在中性pH介质中进行了密度泛函理论（DFT）和经典分子动力学（MD）模拟。已发现范德华相互作用力在胶束中姜黄素的稳定中起主要作用，而非库仑力。还观察到在盐存在下范德华相互作用不受影响。然而，正如MD模拟结果所示，添加盐后胶束的尺寸更紧凑。均方根偏差（RMSD）结果表明，SAIL形成的胶束在特定时间限制后实现了更大的稳定性。我们的结果表明，SAIL可以作为一种有前景的药物递送系统。
