Selenium-capped cyclic peptide nanoparticles for penicillamine drug delivery: A DFT Study

Abstract

Using a model for performance of penicillamine (PCA) anti-cancer drug on selenium-cyclic peptide nanoparticle (CPSeNP), 11 noncovalent configurations have been investigated. Se8 ring model and cyclooctaglycine have been used for selenium nanoparticle (SeNP) and cyclic peptide (CP), respectively. Binding energies, quantum molecular descriptors and solvation energies have been studied in gas phase and water at M06-2X /6-31G** level of theory. The calculated energies represent the high-energy stability of CPSeNP/PCA 1-11 configurations. Solvation energies showed that drug solubility increases, which is a major factor for their use in drug delivery. Regarding to quantum molecular descriptors such as hardness and electrophilic power, the drug reactivity increases in the vicinity of SeNP. The QTAIM analysis revealed that intramolecular interaction Se-L (L =O, H , S, C , N) plays an important role in the system. Se-L interaction in all configurations is relevant to weak interactions. The configurations that PCA drug is located in parallel with the carrier (CPSeNP) are more stable than penicillamine-CP or penicillamine-SeNP systems.