The capability of pure and metal-encapsulated all boron fullerenes (B40) as nanocarriers for β-Lapachone anticancer drug delivery: DFT study

This work employs density functional theory (DFT) to explore the interactions between the anticancer agent β‑Lapachone (β‑Lap) and pristine B40 fullerenes as well as their potassium- and magnesium-encapsulated counterparts (K@B40 and Mg@B40). The results reveal significant interactions affecting the electronic structures of these molecules, with stable complexes formed and a notable reduction in energy gaps, indicating effective β-Lap adsorption. The β-Lap drug exhibits stronger binding to metal-encapsulated fullerenes than to pristine B40 in both aqueous and gas environments, with binding energies in water of approximately -5.2 kcal/mol for B40, -82.9 KCal/mol for Mg@B40, and -55.7 KCal/mol for K@B40. In aqueous media, the dipole moments of encapsulated complexes rise to nearly twice their gas-phase values. To complement the electronic structure insights, we employ Quantum Theory of Atoms in Molecules (QTAIM) to study the electron densities and their Laplacians, and Natural Bond Orbital (NBO) analysis to evaluate donor–acceptor interactions and charge redistribution within these complexes. Despite the strong adsorption energies, the interaction weakens in acidic conditions, facilitating drug release. These findings suggest that B40 and its metal-encapsulated derivatives are promising nanocarriers for β-Lap delivery, combining strong binding with controlled release potential in biological environments.