Evaluation of solvent and ion effects upon leflunomide adsorption characteristics on (6,0) zigzag single-walled carbon nanotube and immobilized dihydroorotate dehydrogenase activity: A computational DFT and experimental study

First-principles studies on two-dimensional B3O3 adsorbent as a potential drug delivery platform for TEPA anticancer drug

The remarkable properties of pristine B₃O₃ nanosheet as a nanocarrier for adsorption and desorption of TEPA anticancer drug for designing potential drug delivery platform were investigated using periodic DFT calculations. We studied the adsorption energy of all stable complexes formed between the drug molecule and B₃O₃ in gas and aqueous phases along with electronic structure analysis of complexes. Different adsorption configurations were studied for drug/B₃O₃ complexes, including the interaction of the C atom of the triangular ring, O atom in the TEPA drug with the B atom in B₃O₃, and indirect drug interaction the middle of the R1 ring cavity of the B₃O₃ nanosheet. The take-up of TEPA prompts a substantial change of 68.13% in the band gap (E_g) of the B₃O₃ nanosheet in the most stable complex. The present study results affirmed the application of B₃O₃ nanosheet as a potential vehicle for TEPA drugs in the treatment of cancerous tissues.

CNT-based nanocarrier loaded with pyrimethamine for adipose mesenchymal stem cells differentiation and cancer treatment: The computational and experimental methods

Pyrimethamine is an effective drug in the cancer cell treatment and is a dihydrofolate reductase inhibitor. In this work, the amount of drug loading up on CNT and its cytotoxicity effect upon MCF-7 cell lines was surveyed. The novel applications of some drugs and nanocarriers can induce the differentiation of adipose mesenchymal cells into nerve cells. Hence carbon nanotube-pyrimethamine was used to differentiate mesenchymal stem cells into the neural category, for the first time. The results of NSE and NFM gene expression level were evaluated using the real-time PCR. A detailed study on the interaction between pyrimethamine anticancer drug and (6, 0) zigzag single-walled carbon nanotube was performed by DFT/B3LYP and DFT/M06-2X with 6-31G* basis set calculations in gas phase and in solvent using the PCM. Different configurations of the adsorbed pyrimethamine onto the CNT surface were studied. Based on the results, the process of pyrimethamine adsorption on diff ;erent sites on the outer wall of the nanotube was exothermic and configurations were stable. The adsorption energy values indicated that the pyrimethamine molecule could be physically adsorbed on the external surface of the SWCNT. The QTAIM was used for characterizing the nature of the interactions between the pyrimethamine and the selected nanocarrier.

Modeling the interaction between anti-cancer drug penicillamine and pristine and functionalized carbon nanotubes for medical applications: density functional theory investigation and a molecular dynamics simulation

The present study focuses on the prediction and investigation of binding properties of penicillamine with pure (5,5) single-walled carbon nanotube (SWCNT) and functionalized SWCNT (f-SWCNT) through the B3LYP and M06-2X functionals using the 6-31G** basis set. The electronic and structural properties, adsorption energy and frontier molecular orbitals of various configurations are examined. Our theoretical results indicated that the interaction of the nanotubes with penicillamine molecule is weak so that the drug adsorption process is typically physisorption. Also, results of theoretical calculations show that the adsorption of the drug molecule on f-SWCNT is stronger with shorter intermolecular distances in comparison to pure SWCNT. The natural bond orbital (NBO) analysis of studied systems demonstrates that the charge is transferred from penicillamine molecule to the nanotubes. Furthermore, molecular dynamics (MD) simulation is employed to evaluate the dynamic and diffusion behavior of drug molecule on SWCNT and f-SWCNT. Energy results show that drug molecule spontaneously moves toward the carriers, and the van der Waals energy contributions in drug adsorption are more than electrostatic interaction. The obtained results from MD simulation confirm that the functionalization of SWCNT leads to increase in the solubility of the carrier in aqueous solution.Communicated by Ramaswamy H. Sarma.

A combined molecular dynamics simulation and quantum mechanics study on mercaptopurine interaction with the cucurbit [6,7] urils: Analysis of electronic structure

In the current study, the probability of complex formation between mercaptopurine drug with cucurbit[6]urils and cucurbit[7]urils has been investigated. The calculations for geometry optimization of complexes have been carried out by means of DFT (B3LYP), DFT-D (B3LYP-D) and M06-2X methods. The Atoms In Molecules (AIM), Natural Bond Orbital (NBO), NMR, the density of states (DOSs) and frontier molecular orbital (MO) analyses have been done on the inclusion complexes. In addition, the UV-Vis spectra of the first eight states have been obtained by CAM-B3LYP/TD-DFT calculation. The obtained results of the complexation process reveal that CB[7]-DRG complexes are more favorable than that of CB[6]-DRG interactions. Furthermore, our theoretical results show that configurations III and I are the most stable configurations related to the CB[6]/DRG and CB[7]/DRG interactions, respectively. The positive ∇²_ρ(r) and HC values at the bond critical points indicate that exist the weak H-bonds between CB[6] and CB[7] with H atoms of the drug molecule. The obtained negative binding energy values of CB[7]-DRG interaction in solution phase show the stability of these complexes in the aqueous medium. Also, all of the observed parameters of molecular dynamics simulation such as the number of contacts, hydrogen bonding, center-of-mass distance and van der Waals energy values confirm the encapsulation of mercaptopurine molecule inside the cucurbit[7]urils cavity at about 3.2ns.