Effect of thiol-functionalised silica on cisplatin adsorption

Abstract

This study contributes to the investigation related to guest–host interactions between the chemotherapeutic agent cisplatin and a functionalised silica matrix in order to improve and find new materials such as drug carriers. The adsorption of cisplatin and its complexes, cis-[PtCl(NH3)2]+ and cis-[Pt(NH3)2]2+, on a SH-functionalised SiO2(111) surface has been studied by the atom superposition and electron delocalisation method. The adiabatic energy curves for the adsorption of the drug and its products on the delivery system were considered. The electronic structure and bonding analysis were also performed. The molecule and their complex are adsorbed on the functionalised surface resulting in a major absorption of the cis-[Pt(NH3)2]2+ complex. The molecule–surface interactions are formed via –SH group. The molecule/complexes SH electron-donating effect plays an important role in the catalytic reaction. The more important drug–carrier interactions occur through the Cl–H bond for the adsorption of cis-[PtCl2(NH3)2] and cis-[PtCl(NH3)2]+, and through the Pt–S and Pt–H interactions for cis-[Pt(NH3)2]2+ adsorption. When the new interactions are formed, the functionalised carrier maintains their matrix properties while the molecule is the most affected after adsorption. The Pt atomic orbitals present the most important changes during adsorption.