Adsorption properties study of boron nitride fullerene for the application as smart drug delivery agent of anti-cancer drug hydroxyurea by density functional theory

The boron nitride fullerenes (BNFs) nanostructures which are chemically stable and noncytotoxic in human bodies, are ideal for the delivery of various drugs. In this study, adsorption properties and drug delivery capability of BNFs as drug vehicles for the anti-cancer drug hydroxyurea (HU) were explored by density functional theory method with solvent effect explicitly treated. Optimized structures suggest that the most favorable adsorption sites of HU on the fullerene are the B atoms in the four-membered rings. The HU drug can be adsorbed chemically on the local pyramidal site of BNFs by the O atom of carbonyl groups. Variation of the adsorption energy with respect to the pyramidalization angle (PA) of BNF surface shows the adsorption energy is highly related with PA. Analyses of the density of states, HOMO-LUMO orbitals and quantum molecular descriptors demonstrate that the electronic properties of fullerene and drug are slightly changed. UV-Vis spectra of the drug-fullerene interaction system were also surveyed to explore the excited state properties of the drug-fullerene complexes. Adsorption peaks of the UV-Vis spectra show a sizable red-shift when the drug is adsorbed on the surface, which indicates the fullerenes are also candidate of optic sensor for the detecting and monitoring of the drug molecule. Drug release mechanism shows the drug can be released in the cancerous tissues where the pH is low. This study provides detailed interaction mechanism of the drug with BNF and reveals the BNF can be smart drug delivery vehicle for the HU drug. (C) 2020 Elsevier B.V. All rights reserved.