DFT and MD investigations on the functionalized boron nitride nanotube as an effective drug delivery carrier for Carmustine anticancer drug

Abstract

In the present work, we apply density functional theory (DFT) calculations to investigate the drug delivery performance of the boron nitride nanotube (BNNT) having hydroxyl functional groups (-OH) for Carmustine (BCNU) agent in the gas phase and water environment. Based on the DFT results, it is found that the interaction between BCNU molecule and functionalized boron nitride nanotube (f-BNNT) is weak; so that, the adsorption of the BCNU drug on the nanotube surface is typically physisorption. Based on the structural characteristics, the stability of the BCNU/f-BNNT complexes contributed to the formation of the intermolecular hydrogen bonds (HBs) between the BCNU drug and hydroxyl groups of BNNT which confirmed by Bader theory of atoms in molecules (QTAIM) results. Our theoretical results show that the structural properties of BCNU molecule doesn't significantly change upon adsorption of drug molecule on f-BNNT. Moreover, the natural bond orbital (NBO) analysis show in BCNU/f-BNNT complexes, the charge transfers from f-BNNT to Carmustine drug and the electronic properties of BCNU drug are not affected during the adsorption process on the nanotube surface. Finally, the effects of drug concentration and temperature on the adsorption mechanism of BCNU molecules are investigated by molecular dynamics (MD) simulation. Such results provide valuable information on the potential applications of functionalized boron nitride nanotubes in the fields of drug delivery within biological systems.