THERMODYNAMIC STUDY OF LEVODOPA DRUG ADSORPTION ON ZIGZAG BORON NITRIDE NANOTUBES BY DENSITY FUNCTIONAL THEORY (DFT) METHOD

Background & Aims:

The overall goal of utilizing nanotubes in drug delivery is to treat a disease effectively with minimum side effects and control the drug release rate. With common methods of taking the medication, such as orally and intravenously, the drug is distributed throughout the body, and the whole body is affected by the drug, and adverse side effects occur. With the development of new methods of drug delivery, maximum effectiveness can be achieved without harming other tissues. In this research, considering the importance of Levodopa as the first line of treatment for Parkinson's disease, the interaction of this drug on boron nitride nanotubes (BNNTs) as a carrier and the possibility of forming a stable complex between them was investigated.

Materials & Methods:

In the present thermodynamic study, the adsorption of Levodopa on boron nitride nanotubes was investigated using density functional theory (DFT). B3LYP/6-31G(d) method and basis set was used to optimize the structure of nanoboron nitride and Levodopa drug. The interaction energy was calculated in order to determine the stability of drug adsorption on boron nitride nanotubes.

The amount of absorpted energy and enthalpy change were negative and so the absorption process was exothermic and thermodynamically favorable. The results of Natural Bonding Orbital (NBO) theory calculations showed that Levodopa has the role of electron donor and boronitride nanotube has the role of electron acceptor, which has changed the stability energy of the bonds in the nanotube. The same effect was also proved by molecular electrostatic potential. Analysis of the results obtained from the atom-in-molecule theory (AIM) revealed the partial covalent nature of the levodopa-nanotube complex.

The results of the study of adsorption energy, thermodynamic functions, structural parameters, AIM parameters, and NBO analysis showed that the drug absorption process was favorable and considering the possibility of forming a stable complex, bornitride nanotubes are expected to be suitable carriers for delivering Levodopa to target cells.