Molecular modeling of adsorption of 5-aminosalicylic acid in the halloysite nanotube

Abstract

Halloysite nanotubes are becoming interesting materials for drug delivery. The knowledge of surface interactions is important for optimizing this application. The aim of this work is to perform a computational study of the interaction between 5-aminosalicylic acid (5-ASA) drug and halloysite nanotubes for the development of modified drug delivery systems. The optimization of this nanotube and the adsorption of different conformers of the 5-ASA drug on the internal surface of halloysite in the presence and absence of water were performed using quantum mechanical calculations by using Density Functional Theory (DFT) and methods based on atomistic force fields for molecular modeling, respectively. ; Authors are thankful to Helio Anderson Duarte for providing atomic coordinates of a slice of halloysite and César Viseras for their fruitful discussions, and to the CSIC Computational Center for computation facilities. This work is funded by the Andalusian Government projects (RNM1897) and the MINECO project FIS2016-77692-C2-2P. It also supported by the Egyptian Cultural Affairs and Missions Sector (Plan 2013-2014), Ministry of Higher Education. M.E.A. is especially thankful to the Egyptian Cultural Affairs and Missions Sector, Mahmoud Mohamed El Rahmany, and Mahmoud Hassaan El-Basha (Faculty of Science, Al-Azhar University in Cairo), for their encouragements and fruitful discussions.