Computational screening of metal-doped borospherene B40 for 5-fluorouracil drug delivery

The interaction between B₄₀M (M = K ∼ Zn) nanocages and 5-fluorouracil (5-Fu) anticancer drug has been systematically investigated using density functional theory (DFT) in this study. The different doping modes and spin multiplicity have been explored to screen out the most stable B₄₀M. Among these considered boron-based nanocages, B₄₀M (M = K, Ti, V, and Fe) exhibit remarkable adsorption energies (E_ad = −18.91 ∼ −20.41 kcal/mol) toward 5-Fu. It is found that the KO2 bond formed between B₄₀K and 5-Fu shows typical ionic characteristics, while the M-O bonds between B₄₀M (M = Ti, V, and Fe) and 5-Fu exhibit both of ionic and covalent bonding characteristics. Interestingly, the E_ad value of 5-Fu@B₄₀V decreases from −20.34 to −9.61 kcal/mol in a weakly acidic environment. Based on these findings, the B₄₀M (M = K, Ti, V, and Fe) nanocages are identified as promising drug carriers for 5-Fu and even other drugs.