The role of amino acid functionalization for improvement of adsorption Thioguanine anticancer drugs on the boron nitride nanotubes for drug delivery

Herein, density functional theory (DFT) calculations were employed to evaluate the performance of a drug delivery system for cysteine amino acid functionalized carbon nitride nanotubes (f-C3NNTs) for Thioguanine (TG) anticancer drugs. Moreover, to compare better, pristine C3NNTs were considered for the calculations. According to acquired results, one can realize that the process of drugs adsorption on the nanostructure has occurred spontaneously with the release of heat. It should be mentioned that f-C3NNTs/TG complexes have interactions with the highest strength. Based on our calculations, compared with unfunctionalized C3NNTs, f-C3NNTs have a shorter distance of adsorption, higher adsorption capability, and higher solubility upon the adsorption of TG. Due to the polarity of all complexes, they are soluble in aqueous environments. According to the quantum molecular descriptors, f-C3NNTs have higher reactivity compared with pristine C3NNTs. According to thermodynamic investigations, TG molecule's interactions with f-C3NNTs are exothermic and spontaneous. Thus, f-C3NNTs can be considered a potential candidate for the adsorption of TG drugs as a drug delivery system.