pH dependence of dacarbazine adsorption on activated carbon: DFT study

ROMÁN, G.; NOSEDA GRAU, E.; DÍAZ COMPAÑY, A.; JUAN, A.; SIMONETTI, S.

EPL (Europhysics Letters)

EDP Sciences

Año: 2019 vol. 126

Density Functional Theory (DFT) methods supply important aspects of dacarbazineadsorption on a carbon surface, by providing atomistic details through molecular modeling. Theweak interactions between dacarbazine and pristine carbon surface could limit the medicinal treatmentefficiency. Nevertheless, the carboxyl (-COOH) functionalized carbon surface has a significanteffect on the adsorption of dacarbazine at neural and lower pH. At low pH, the carboxyl-carbonsurface acts as attraction centre for the protonated drug via hydrogen bonding and electrostaticinteractions, which result in lower adsorption energy and better controlled release. At pH = 7,they are expected an increased rate and released amount of dacarbazine because the electrostaticinteractions decrease between the neutral molecule and the carboxyl functionalized surface. Athigh pH, the deprotonated drug and the ionized (-COO−) carboxyl-surface present stronger electrostaticrepulsion and the highest adsorption energy, which could increase the dacarbazine releaserate. Carboxyl functionalized carbon surfaces could improve dacarbazine drug delivery adaptingto therapy requirement according to the pH.