Fate of Sc-Ion Interaction With Water: A Computational Study to Address Splitting Water Versus Solvating Sc Ion

Preparation of disulfiram-Cu2+-polylactide nanofibrous membranes via electrostatic spinning and evaluation of their in vitro anticancer effects

The antitumor effects of disulfiram (DSF) -a conventional medication used to treat alcohol dependence-have been documented in numerous studies. However, because of its low water solubility and Cu2+-dependent anticancer effects, the application of DSF in cancer therapy has been limited. Nanofibrous membranes produced via electrospinning have large specific surface areas. Consequently, they have been extensively used in biomedical applications, such as tissue scaffolding, drug delivery. In this study, a polylactic acid nanofibrous membrane was designed to encapsulate Cu2+ and DSF. The encapsulated drug was released when the membranes came into contact with the tumor tissue. DSF functioned as a Cu-ion carrier and combined with Cu2+ to induce tumor-cell apoptosis. The anticancer properties of the drug-loaded nanofibrous membrane were verified at the cellular level using in vitro experiments with cells. The results indicated that DSF and Cu2+ were released from the fiber membrane, and the combination of DSF and Cu2+ exhibited a better of cancer are proposed.

Computational simulation on the study of Tacrolimus and its improved dermal retention using Poly(Ԑ-caprolactone) nanocapsules

Tacrolimus (TAC) is a drug from natural origin that can be used for topical application to control autoimmune skin diseases such as atopic dermatitis, psoriasis, and vitiligo. Computational simulation based on quantum mechanics theory by solving Schrödinger Equation for n-body problem may allow the theoretical calculation of drug geometry, charge distribution and dipole moment, electronic levels and molecular orbitals, electronic transitions, and vibrational transitions. Additionally, the development of novel nanotechnology-based delivery systems containing TAC can be an approach for reducing the dose applied topically, increasing dermal retention, and reducing the reported side effects due to the controlled release pattern. Firstly, this paper was devoted to obtaining the molecular, electronic, and vibrational data for TAC by using five semi-empirical (SE) methods and one Density Functional Theory (DFT) method in order to expand the knowledge about the drug properties by computational simulation. Then, this study was carried out to prepare TAC-loaded poly(ԑ-caprolactone) nanocapsules by interfacial polymer deposition following solvent displacement and investigate the in vitro drug permeation using the Franz diffusion cell and the photoacoustic spectroscopy. Computational simulations were compared in the three schemes SE/SE, SE/DFT, and DFT/DFT, where the first method represented the procedure used for geometry optimization and the second one was performed to extract electronic and vibrational properties. Computational data showed correspondence with TAC geometry description and electronic properties, with few differences in HOMO - LUMO gap (Δ) and dipole values. The SE/DFT and DFT/DFT methods presented a better drug description for the UV-Vis, Infrared, and Raman spectra with low deviation from experimental values. Franz cell model demonstrated that TAC was more delivered across the Strat-M® membrane from the solution than the drug-loaded poly(ԑ-caprolactone) nanocapsules. Photoacoustic spectroscopy assay revealed that these nanocapsules remained more retained into the Strat-M® membranes, which is desirable for the topical application.

Tracing the transition from covalent to non-covalent functionalization of pyrene through C-, N-, and O-based ionic and radical substrates using quantum mechanical calculations

Pyrene is one of the widely investigated aromatic hydrocarbons given its unique optical and electronic properties. Modulating inherent characteristics of pyrene via covalent or non-covalent functionalization has been attractive for a wide variety of advanced biomedical and other device applications. In this study, we have reported the functionalization of pyrene via C, N, and O based ionic and radical substrates, and emphasized the transition of covalent to non-covalent functionalization through making the modulation in the substrate. As expected, strong interactions were observed for cationic substrates, however, anionic substrates also exhibited a competitive binding strength. For instance, methyl and phenyl substituted CH3 complexes exhibited IEs in the range of -17 kcal mol-1 to -127 kcal mol-1 and -14 kcal mol-1 to -95 kcal mol-1 and for cationic and anionic substrates, respectively. The analysis of topological parameters showed that un-substituted cationic, anionic, and radical substrates interact with pyrene via covalent interactions, and further become non-covalent upon methylation and phenylation of the substrates. In cationic complexes, the polarisation component is observed to be dominating the interactions, whereas highly competitive contributions from polarization and exchange components were observed in anionic and radical complexes. The contribution of the dispersion component increases with an increase in the degree of methylation and phenylation of the substrate, and starts dominating once the interactions become non-covalent in nature.

Binding propensity and selectivity of cationic, anionic, and neutral guests with model hydrophobic hosts: A first principles study

Computations play a critical role in deciphering the nature of host-guest interactions both at qualitative and quantitative levels. Reliable quantum chemical computations were employed to assess the nature, binding strength, and selectivity of ionic, and neutral guests with benzenoid hosts. Optimized complex structures reveal that alkali and ammonium ions are found to be in the hydrophobic cavity, while halide ions are outside, while both complexes elicit substantial binding energy. The origin of the selectivity of host toward the guest has been traced to the interaction and deformation energies, and the nature of associated interactions is quantified using energy decomposition and the Quantum Theory of Atoms in Molecules analyses. While the larger hosts lead to loosely bound complexes, as assessed by the longer intermolecular distances, the binding strengths are proportional to the size of the host systems. The binding of cationic complexes is electrostatic or polarization driven while exchange term dominates the anionic complexes. In contrast, dispersion contribution is a key in neutral complexes and plays a pivotal role in stabilizing the polyatomic complexes.