Understanding the adsorption performance of hetero-nanocages (C12-B6N6, C12-Al6N6, and B6N6-Al6N6) towards hydroxyurea anticancer drug: a comprehensive study using DFT.

Cancer is a paramount health challenge to global health, which forms tumors that can invade nearby tissues and spread to neighboring cells. Recently, nanotechnology has been used to control the growth of cancer, in which anticancer drugs are delivered to cancerous cells via nanoparticles without damaging healthy tissues. In this study, DFT investigations were carried out to examine the adsorption behavior of C₂₄, B₁₂N₁₂, and Al₁₂N₁₂ nanocages as well as their heterostructures C₁₂-B₆N₆, C₁₂-Al₆N₆, and B₆N₆-Al₆N₆ towards the hydroxyurea (HU) anticancer drug. In this regard, adsorption energy, interaction distance between the drug and nanocages, charge transfer, energy gap, dipole moment, quantum molecular descriptors, work function, and COSMO surface analysis were analyzed to understand their adsorption performance. Findings demonstrate that the adsorption energies of two hetero-nanocages on their hexagonal (S_H) and tetragonal (S_T) sites are favorable for the drug delivery process. The computed adsorption energy of B₆N₆-Al₆N₆ of the S_T/AlN site is 183.59 kJ mol^-1, which is higher than that of the C₁₂-Al₆N₆ nanocage, including minimum adsorption distances. Negative adsorption energy with low adsorption distances implies an attractive interaction between the drug and nanocages. During the interaction, a significant amount of charge is transferred between the drug and nanocages. Furthermore, for both complexes, larger dipole moments were observed in water media compared to gas media. From DOS spectra, prominent peaks were found in the Fermi level after adsorption of HU on the nanocages, implying the reduction of the energy gap. Noticeable overlaps between the PDOS spectra of the nanocages and HU's close contact atom demonstrate the formation of chemical bonds between two specific atoms. Therefore, it can be concluded that among the nanocages, C₁₂-Al₆N₆ and B₆N₆-Al₆N₆ may be suitable carriers for HU drug.