Mechanistic, Energetic and Structural Studies of γ-Fe2O3 Nanoparticles Functionalized with Drug Artemisinin.

Using density functional theory, three noncovalent interactions and mechanism of covalent functionalization of drug artemisinin onto γ-Fe₂O₃ nanoparticles have been investigated. Quantum molecular descriptors of noncovalent configurations were studied. It was specified that binding of drug artemisinin with γ-Fe₂O₃ nanoparticles is thermodynamically suitable. Hardness and the gap of energy between LUMO and HOMO of artemisinin drug are higher than those of noncovalent artemisinin-γ-Fe₂O₃ nanoparticle configurations, showing the reactivity of artemisinin increases in the presence of γ-Fe₂O₃ nanoparticles. Artemisinin can bond to γ-Fe₂O₃ nanoparticles through carbonyl group. The activation energies, the activation enthalpies and the activation Gibbs free energies of this reaction were calculated. The activation parameters and thermodynamic data indicate that this reaction is exothermic and spontaneous and can take place at room temperature. These results could be generalized to other similar drugs. [ABSTRACT FROM AUTHOR]