Cisplatin hydrolysis on promoted-SiO2(100) surfaces

A. DIAZ COMPAÑY; S. SIMONETTI

Conferencia; 3rd International Conference and Exhibition on Materials Science & Engineering; 2014

Different types of silica are widely used as efficient adsorbents, selective absorbents and active phase carriers in catalysis. Chemical modification of the surface of silica receives special interest because this process allows researchers to regulate and change adsorption properties and technological characteristics. Studies have shown that silica matrixes could improve drug delivery systems. In this work, the cisplatin hydrolysis on a SiO2(100) hydrated surface is investigated by tight binding calculation. Cisplatin (cis-[PtCl2(NH3)2]) is a coordination compound, used in the treatment of several solid tumors. Calculations show that, during adsorption, the silica surface maintains their matrix properties and the major changes occur in cisplatin′s molecule. The cisplatin molecule has small interactions with neighbour OH groups of the hydrated surface and the hydrolysis process is not favourable on the SiO2(100) hydrated surface. The adsorption properties of the SiO2(100) are improved considering the surface?s modification with K, Mg or NH2 promoters. 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) functionalized surface. The adsorption of cisplatin molecule and their complexs is strengthened. The electron density changes positively affect the adsorption strength of the cisplatin molecule and their complexs. Cisplatin is best adsorbed by 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 favoring the molecule/complexs-surface interaction.