The performance of the single-walled carbon nanotube covalently modified with polyethylene glycol to delivery of Gemcitabine anticancer drug in the aqueous environment

Abstract

A computational investigation of Gemcitabine drug adsorption on the single-walled carbon nanotube covalently modified with polyethylene glycol in a series of the configurations is studied using density functional theory calculations. It is observed that O…H hydrogen bonds are the dominating intermolecular interactions during the complex formation between anti-cancer drug and the nanotube. The studied hydrogen-bonded complexes are treated theoretically to elucidate the nature of the intermolecular hydrogen bonds, geometrical structures, the binding energy and electron density topological analysis. The existence of the bond critical points between hydrogen and the electronegative atoms and their concomitant bond paths which connect the bond critical points to the two interacting atoms confirm by Quantum Theory of Atoms in Molecules method. In addition, considering the charge transfer for all of the adsorbed configurations reveals the capability of the drug molecule to accept precisely the electron from the functionalized carbon nanotube during the drug adsorption on external surface of the carbon nanotube. Also, the effect of weight percent of polyethylene glycol on the drug adsorption strength is investigated by molecular dynamics simulations. Communicated by Ramaswamy H. Sarma