Assessment of the drug delivery potential of graphene, boron nitride and their in-plane doped structures for hydroxyurea anti-cancer drug via DFT study

Globally, cancer is the most common cause of mortality among all deadly diseases. As a result, a nanotechnology-based drug delivery system is used to improve the efficacy of cancer treatment, which provides an improved therapeutic index and delivers multiple drugs directly to the tumor site. In the present work, DFT calculations were employed to investigate the surface adsorption of a hydroxyurea (HU) anticancer drug on pristine graphene (GP), boron nitride (B24N24), and doped GP by replacing some of its carbon atoms with boron (B) and nitrogen (N) atoms to form C30B9N9, C16B16N16, and C6B21N21 nanosheets. In gas media, HU is adsorbed on these C30B9N9, C16B16N16, C6B21N21, and B24N24 nanosheets with adsorption energies of -0.70, -3.03, -2.47, and -1.96 eV, respectively. Alternatively, in water solvent media, the adsorption energies of C30B9N9, C16B16N16, C6B21N21, and B24N24 are -0.82, -0.29, -0.15, and -0.26 eV, respectively. The energy gaps of the nanosheets were found to be 0.288, 0.174, 0.14, and 4.562 eV before adsorption, respectively. After the adsorption of HU on the proposed nanosheets, the energy gap was reduced to 0.15 eV for C16B16N16. According to the DOS spectra, noticeable peaks appeared in the Fermi level after the adsorption of HU on the nanosheets, which indicates the reduction of the energy gap. Quantum molecular analysis predicted that the chemical potential, electrophilicity index, and nucleophilicity index of C16B16N16 increased, whereas global hardness decreased, indicating high reactivity. Therefore, it can be concluded that among the proposed nanosheets, C16B16N16 would be an appropriate carrier for the HU drug.