Application of zinc oxide nano-tube as drug-delivery vehicles of anticancer drug

CONTEXT

Zinc oxide nano-tube (ZnONT) nano-structures, which possess chemical stability and non-toxicity in the human body, are considered promising for delivering different drugs. Within this work, we scrutinized the drug delivery capability of the ZnONT and its adsorptional properties as a drug delivery vehicle (DDV) for hydroxyurea (HU) as an anti-cancer drug through density functional theory along with the solvent impacts. Based on the optimized structures, it can be suggested that Zn atoms of ZnONT are the ideal sites on this nano-tube for the adsorption of HU. HU had a strong physical adsorption through the O atom of carbonyl groups onto the local pyramidal site of the ZnONT. At 1.96 Å and Ead of -39.28 kcal/mol, in the configuration which was favorable in terms of energy, there was an interaction between the O atoms of -C=O group of the drug and a Zn atom of the ZnONT. In order to scrutinize the excited state properties of the HU-ZnONT complex, we also examined the UV/Vis data of the HU/ZnONT interaction system. Following the adsorption of HU onto the surface of the ZnONT, there was a significant red-shift based on the maximum absorption wavelength, showing that the ZnONT is an ideal candidate for optic sensors in order to detect and monitor the drug molecule. HU could be released in the cancer tissues where pH was low based on the drug release mechanism. The current work thoroughly investigated the mechanism of interaction between the ZnONT and HU, showing that ZnONT can be used for the smart drug delivery of HU. Overall, the findings suggest that ZnONT could be used as an efficient drug-delivery system for the HU drug to treat various types of cancer.

METHODS

In this work we used B3LYP-gCP-D3 functional and the basis set LANL2DZ on the transition metal (Zn) and the basis set cc-pVDZ on the others. GAMESS software program was employed for performing the calculations. we performed analyses, including charge transport, molecular electrostatic potential surface (MEP), energetic, electronic, natural bond orbitals (NBOs), and structural optimizations.

Blue M2: an intermediate melanoidin studied via conceptual DFT

In this computational study, ten density functionals, viz. CAM-B3LYP, LC-ω PBE, M11, M11L, MN12L, MN12SX, N12, N12SX, ω B97X, and ω B97XD, related to the Def2TZVP basis sets, are assessed together with the SMD solvation model for calculation of the molecular properties and structure of blue-M2 intermediate melanoidin pigment. All the chemical reactivity descriptors for the system are calculated via conceptual density functional theory (DFT). The active sites suitable for nucleophilic, electrophilic, and radical attacks are selected by linking them with the Fukui function indices, electrophilic Parr functions, and condensed dual descriptors Δf(r), respectively. The prediction of the maximum absorption wavelength is considerably accurate relative to its experimental value. The study reveals that the MN12SX and N12SX density functionals are the most appropriate density functionals for predicting the chemical reactivity of the molecule under study.