pH dependence of dacarbazine adsorption: DFT study of the drug carried on pristine and carboxyl functionalized carbon surfaces

G. ROMAN; E. NOSEDA GRAU; A. DIAZ COMPAÑY; A. JUAN; S. SIMONETTI

EUROPHYSICS LETTERS

EPL ASSOCIATION

Año: 2019 vol. 126 p. 1 - 6

0295-5075

Density Functional Theory implemented by the Vienna Ab-initio Simulation Package methods supply important aspects of dacarbazine adsorption on carbon surface, by providing atomistic details through molecular modeling. It is observed weak interactions between dacarbazine and pristine carbon surface that considerably limit medicinal treatment efficiency. Nevertheless, the carboxyl functionalized carbon surface could have a significant effect on adsorption according pH. At low pH, the carboxylic groups (-COOH) at the surface acts as attraction centre for the protonated drug via hydrogen bonding and electrostatic interactions, which could be result in controlled release. At pH=7, the increased rate and amount of dacarbazine released could be expected because the electrostatic interactions decrease between the neutral molecule and the carboxyl group. At high pH, the deprotonated drug and the ionized (-COO-) carboxylic group present stronger electrostatic repulsion, which could increase the decarbazine release rate. Carboxyl functionalized carbon surfaces could improve dacarbazine drug delivery adapted to therapy requirement according pH medium.