Adsorption behavior of letrozole on pure, Ge- and Si-doped C60 fullerenes: a comparative DFT study

Enhanced dissolution of anticancer drug letrozole from mesoporous zeolite clinoptilolite

High dissolution of anticancer drugs directly adsorbed onto porous carriers is indispensable for the development of drug delivery systems with high bioavailability. We report direct adsorption/loading of the anticancer drug letrozole (LTZ) onto the clinoptilolite (CLI) zeolite after the surface activation.In vitroLTZ dissolution from the CLI zeolites reached 95 % after 23 h in an acidic medium, being faster than the dissolution of the pure LTZ molecules. Fast dissolution occurs due to uniform exposure of the LTZ onto the external surface of the CLI zeolites, being accessible to the solvent for dissolution. On the other hand, the LTZ molecules were hidden in the bulk phase, giving a slow dissolution rate. Small positive value of the CLI/LTZ adsorption energy of 0.06 eV suggests that the release process is favourable in aqueous media. The main merit of the CLI/LTZ system is its quick onset of action and high bioavailability. This work demonstrates a possibility of enhancement of the dissolution of poorly soluble LTZ from the CLI zeolite, being promising for the further development of drug delivery systems.

Effects of Ge, Si, and B doping on the adsorption and detection properties of C60 fullerene towards methadone in gas and aqua phases: a DFT study

CONTEXT

Methadone can be abused and caused addictive and has various side effects. Therefore, the development of a fast and reliable diagnosis technique for its monitoring is essential. In this work, applications of C₆₀, GeC₅₉, SiC₅₉, and BC₅₉ fullerenes were investigated utilizing density functional theory (DFT) to find a suitable probe for methadone detection. The C₆₀ fullerene indicated weak adsorption energy for methadone sensing. Therefore, for the construction of the fullerene with good property for methadone adsorption and sensing, the GeC₅₉, SiC₅₉, and BC₅₉ fullerenes have been studied. The adsorption energy of GeC₅₉, SiC₅₉, and BC₅₉ in the most stable complexes were calculated at -2.08, -1.26, and -0.71 eV, respectively. Although GeC₅₉, SiC₅₉, and BC₅₉ all showed strong adsorption, only BC₅₉ present a high sensitivity for detection. Further, the BC₅₉ fullerene showing a proper short recovery time (about 1.11 × 10^-6 s for methadone desorption). Water as a solution is used to simulate the behavior of fullerenes in the body fluids, and results indicated that the selected pure and complex nanostructures are stable in water. The UV-vis spectrums indicated that the after adsorption of methadone on the BC₅₉ exhibits shift toward the lower wavelengths (blue shift). Therefore, our investigation indicated that the BC₅₉ fullerene is an excellent candidate for methadone detection.

METHODS

The interaction of methadone with pristine and doped C60 fullerenes surfaces was calculated using the density functional theory calculations. The GAMESS program and M06-2X method with a 6-31G(d) basis set were used for computations. Since the M06-2X method overestimates the LUMO-HOMO energy gaps (Eg) of carbon nanostructures, the HOMO and LUMO energies and Eg were investigated at the B3LYP/6-31G(d) level of theory using the optimization calculations. UV-vis spectra of excited species were obtained through the time-dependent density functional theory. To simulate the human biological fluid, the solvent phase was also evaluated in adsorption studies, and water was considered a liquid solvent.

The computational quantum mechanical investigation of the functionalized boron nitride nanocage as the smart carriers for favipiravir drug delivery: a DFT and QTAIM analysis

Favipiravir (FPV) is an antiviral drug used for the cure of Influenza virus, Ebola virus, Lassa virus etc. because it has excellent preventing ability of entry/exit of the virus into/from the human cells. Boron nitride nanocages have already drawn enormous attention as the delivery vehicle of various drug molecules for their nontoxicity and other lucrative properties. In this research, we have scrutinized the adsorption mechanism of FPV molecule on the exterior surface of pristine, Zn functionalized, and Ni functionalized B12N12 (BN, Zn f-BN, and Ni f-BN) nanocages by applying the DFT/QTAIM method and B3LYP/6-31G(d,p) approach. The adsorption energy (E_Ad) data reveal that the functionalized BN adsorbents can adsorb FPV drug very efficiently compared with the pristine adsorbent (Highest E_Ad is -56.40 kcal/mol for FPV adsorbed Ni f-BN complex). The reduction of the HOMO-LUMO gap up to 67.79% indicates that this drug can be detected by the produced electrical signal very promisingly in the case of f-BN nanocages. The topological parameters also validate the ability of the f-BN nanocages to adsorb the FPV molecule. The effect of the biological environment of our investigated structures has been studied by using water as a solvent, and spontaneous adsorption with high solubility is observed in our calculations. This analysis also reveals that f-BN nanocages can be a potential nanocarrier for the delivery of FPV drug molecule.Communicated by Ramaswamy H. Sarma.

The study of Letrozole adsorption upon CCT nanotube: A DFT/TD-DFT and spectroscopic (excited states and UV/Vis)

In this research, the geometric structure of LTZ and CCT (5,0) was optimized with B3LYP/6-31G * method using the Gaussian 09W program package to investigate the weak interaction of Letrozole (LTZ) and carbon carbon nanotube (CCT). According to the calculation of the release energy, it was found that the drug delivery process is desirable. Also, the structural properties of the title compounds were assessed by thermodynamic and frontier molecular orbital (FMO) parameters. In this study, a series of measures have been performed to detect changes in drug loading properties and non-bonding interactions between the LTZ and CCT (5,0) nanotube. The non-bonding interaction effects of LTZ and CCT over the electronic properties were also evaluated and argued. The research is based on the fact that studies can help to understand the interaction between the LTZ drug and CCT (5,0) nanotube and the development of CCT-based drug release systems. This research aimed to determine variations in electronic properties of anticancer LTZ drug in presences CCT. Then, the reactivity and stability behavior of LTZ drug and on CCT to be examined by density functional theory (DFT). Then, frontier molecular orbital (FMO) and noncovalent interaction (NCI) analyses were performed, which decrease in reactivity described increase in the stability of LTZ drug.