Understanding chitosan as a gene carrier: A DFT study

We described density functional study carried out in order to delve into the interaction between chitosan, a gene carrier and nucleobases. Our study asserts the pivotal role played by hydrogen bonding in chitosan–nucleobase adduct formation. Incorporation of aqueous medium is found to bring about a significant impact on the interaction between the two. Thermochemical analysis suggests the presence of strong thermodynamic driving force for adduct formation in gas phase while no such driving force is observed in aqueous phase. Moreover, except adenine, aromaticity of nucleobases is enhanced by adduct formation with chitosan. Protonation of the nucleobases leads to dissociation of the two constituents of the adducts.