First principles calculations of the adsorption of fluorouracil and nitrosourea on CTF-0; organic frameworks as drug delivery systems for cancer treatment

Therapeutic potential of oxo-triarylmethyl (oxTAM) as a targeted drug delivery system for nitrosourea and fluorouracil anticancer drugs; A first principles insight

In this study, oxygenated triarylmethyl (oxTAM) is investigated by DFT calculations as a drug carrier framework for Nitrosourea (NU) and Fluorouracil (FU) drugs. Based on the adsorption analysis i.e., energies and distances between interacting atoms, it is found that oxTAM exhibits excellent carrier abilities for the delivery of FU (-1.53 eV & 2.00 Å) and NU (-1.33 eV & 2.12 Å) drugs. NCI and QTAIM results indicate the presence of hydrogen bonding in drug-carrier complexes. The values of dipole moment and global chemical descriptors show the significant reactivity of oxTAM for NU and FU drugs. Based on electronic property analysis, FU@oxTAM has a higher adsorption trend for complexation with oxTAM as compared to NU@oxTAM. Moreover, FU can easily release from the carrier due to the decreasing adsorption stability after protonation under an acidic environment as well as a short recovery time observed for the oxTAM carrier surface. Keeping in view all the above parameters, we inferred that oxTAM can serve as a potential drug delivery system for anticancer drugs including, Nitrosourea and Fluorouracil drugs.

Covalent Triazine Framework C6N6 as an Electrochemical Sensor for Hydrogen-Containing Industrial Pollutants. A DFT Study

Industrial pollutants pose a serious threat to ecosystems. Hence, there is a need to search for new efficient sensor materials for the detection of pollutants. In the current study, we explored the electrochemical sensing potential of a C₆N₆ sheet for H-containing industrial pollutants (HCN, H₂S, NH₃ and PH₃) through DFT simulations. The adsorption of industrial pollutants over C₆N₆ occurs through physisorption, with adsorption energies ranging from -9.36 kcal/mol to -16.46 kcal/mol. The non-covalent interactions of analyte@C₆N₆ complexes are quantified by symmetry adapted perturbation theory (SAPT0), quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) analyses. SAPT0 analyses show that electrostatic and dispersion forces play a dominant role in the stabilization of analytes over C₆N₆ sheets. Similarly, NCI and QTAIM analyses also verified the results of SAPT0 and interaction energy analyses. The electronic properties of analyte@C₆N₆ complexes are investigated by electron density difference (EDD), natural bond orbital analyses (NBO) and frontier molecular orbital analyses (FMO). Charge is transferred from the C₆N₆ sheet to HCN, H₂S, NH₃ and PH₃. The highest exchange of charge is noted for H₂S (-0.026 e^-). The results of FMO analyses show that the interaction of all analytes results in changes in the E_H-L gap of the C₆N₆ sheet. However, the highest decrease in the E_H-L gap (2.58 eV) is observed for the NH₃@C₆N₆ complex among all studied analyte@C₆N₆ complexes. The orbital density pattern shows that the HOMO density is completely concentrated on NH₃, while the LUMO density is centred on the C₆N₆ surface. Such a type of electronic transition results in a significant change in the E_H-L gap. Thus, it is concluded that C₆N₆ is highly selective towards NH₃ compared to the other studied analytes.

Probing the Reactions of Thiourea (CH4N2S) with Metals (X = Au, Hf, Hg, Ir, Os, W, Pt, and Re) Anchored on Fullerene Surfaces (C59X)

Upon various investigations conducted in search for a nanosensor material with the best sensing performance, the need to explore these materials cannot be overemphasized as materials associated with best sensing attributes are of vast interest to researchers. Hence, there is a need to investigate the adsorption performances of various metal-doped fullerene surfaces: C₅₉Au, C₅₉Hf, C₅₉Hg, C₅₉Ir, C₅₉Os, C₅₉Pt, C₅₉Re, and C₅₉W on thiourea [SC(NH₂)₂] molecule using first-principles density functional theory computation. Comparative adsorption study has been carried out on various adsorption models of four functionals, M06-2X, M062X-D3, PBE0-D3, and ωB97XD, and two double-hybrid (DH) functionals, DSDPBEP86 and PBE0DH, as reference at Gen/def2svp/LanL2DZ. The visual study of weak interactions such as quantum theory of atoms in molecule analysis and noncovalent interaction analysis has been invoked to ascertain these results, and hence we arrived at a conclusive scientific report. In all cases, the weak adsorption observed is best described as physisorption phenomena, and CH₄N₂S@C₅₉Pt complex exhibits better sensing attributes than its studied counterparts in the interactions between thiourea molecule and transition metal-doped fullerene surfaces. Also, in the comparative adsorption study, DH density functionals show better performance in estimating the adsorption energies due to their reduced mean absolute deviation (MAD) and root-mean-square deviation (RMSD) values of (MAD = 1.0305, RMSD = 1.6277) and (MAD = 0.9965, RMSD = 1.6101) in DSDPBEP86 and PBE0DH, respectively.