Advanced materials for drug delivery: bonding study of cis-[PtCl2(NH3)2] hydrolysis on functionalised-SiO2(100) surfaces

A. DIAZ COMPAÑY; S. SIMONETTI

Conferencia; RSC Conference, Advancing the Chemical Science, Physical Chemistry of Funtionalised Biomedical Nanoparticles; 2014

Cisplatin (cis-[PtCl2(NH3)2]) and its hydrolysis products (cis-[PtCl(NH3)2]+ and cis-[Pt(NH3)2]2+) exhibit a grand pharmacological effect in the treatment of several solid tumours. Studies have shown that silica matrixes could improve drug delivery systems. At the crystal surface, Si atoms are no longer protected by the bulk material from chemical reactions with the environment, and molecular species can absorb onto or bond with surface atoms. These new molecular species can alter the electronic structure and bonding of the SiO2 at the surface. In this work, the cisplatin hydrolysis on a SiO2(100) hydrated surface was investigated by computational calculation. During adsorption, the silica surface maintains their matrix properties and the major changes occur in cisplatin′s molecule. Cisplatin has small interactions with neighbour OH groups of the hydrated surface and the hydrolysis process is not favourable on the SiO2(100) surface. The adsorption properties of the SiO2(100) are improved considering the surface?s modification with K, Mg or NH2 groups. In general, the stability of the system is increased and the molecule/surface distance is reduced when the adsorption is performed using functional groups. The hydrolysis is a favourable process on the SiO2(100) functionalised surface. The adsorption of cisplatin molecule and their complexes is strengthened. The electron density changes positively affect the adsorption strength of the cisplatin molecule and their complexes. Cisplatin is best adsorbed when the surface is functionalised with the NH2 group. The mainly overlap populations correspond to Cl-N, Cl-Si interactions (during cis-[PtCl2(NH3)2] and cis-[PtCl(NH3)2]+ adsorption), and Pt-O, Pt-Si, Pt-H interactions (during cis-[Pt(NH3)2]2+ adsorption). After adsorption, the strength of N-Si, Si-O and N-H bond changes favouring the molecule/complexes-surface interaction.