A Comparative DFT Investigation of the Adsorption of Temozolomide Anticancer Drug over Beryllium Oxide and Boron Nitride Nanocarriers.

Herein, attempts were made to explore the adsorption prospective of beryllium oxide (Be12O12) and boron nitride (B12N12) nanocarriers toward the temozolomide (TMZ) anticancer drug. A systematic investigation of the TMZ adsorption over nanocarriers was performed by using quantum chemical density functional theory (DFT). The favorability of Be12O12 and B12N12 nanocarriers toward loading TMZ was investigated through A↔D configurations. Substantial energetic features of the proposed configurations were confirmed by negative adsorption (E ads) energy values of up to -30.47 and -26.94 kcal/mol for TMZ•••Be12O12 and •••B12N12 complexes within configuration A, respectively. As per SAPT results, the dominant contribution beyond the studied adsorptions was found for the electrostatic forces (E elst = -100.21 and -63.60 kcal/mol for TMZ•••B12N12 and •••Be12O12 complexes within configuration A, respectively). As a result of TMZ adsorption, changes in the energy of molecular orbitals followed by alterations in global reactivity descriptors were observed. Various intermolecular interactions within the studied complexes were assessed by QTAIM analysis. Notably, a favorable adsorption process was also observed under the effect of water with adsorption energy ( reaching -28.05 and -22.26 kcal/mol for TMZ•••B12N12 and •••Be12O12 complexes within configuration A, respectively. The drug adsorption efficiency of the studied nanocarriers was further examined by analyzing the IR and Raman spectra. From a sustained drug delivery point of view, the release pattern of TMZ from the nanocarrier surface was investigated by recovery time calculations. Additionally, the significant role of doping by heavy atoms (i.e., MgBe11O12 and AlB11N12) on the favorability of TMZ adsorption was investigated and compared to pure analogs (i.e., Be12O12 and B12N12). The obtained data from thermodynamic calculations highlighted that the adsorption process over pure and doped nanocarriers was spontaneous and exothermic. The emerging findings provide a theoretical base for future works related to nanocarrier applications in the drug delivery process, especially for the TMZ anticancer drug.

Density functional theory study of the corrosion inhibition performance of 6-mercaptopurine and 6-thioguanine expired drugs toward the aluminium (111) surface.

The potentiality of the 6-mercaptopurine (MP) and 6-thioguanine (TG) expired drugs toward the corrosion inhibition of the aluminium (Al) (111) surface was widely investigated using a series of density functional theory (DFT) calculations. A competition between the anti-corrosive features of the studied drugs in the gas and aqueous phases was conducted on both neutral and protonated forms by means of quantum mechanical descriptors. The results of the electrostatic potential analysis demonstrated the prominent nucleophilic nature of the sulfur and nitrogen atoms over the structures of the examined drugs. The frontier molecular orbital theory findings outlined the higher preferability of TG over MP as a corrosion inhibitor. Upon determining the most beneficial configurations of the MP/TG⋯Al (111) complexes, first-principles molecular dynamics simulations were executed. Interestingly, the competence of the TG drug in the corrosion inhibition process of Al (111) was more extensive than that of the MP one, which was confirmed by the interaction energy values of -1.79 and -1.64 eV, respectively. Upon obtaining the relaxed complexes, the effect of the presence of water solvent on the adsorption process was studied. These findings provide a foundation for developing green anti-corrosive inhibitors for the aluminium surface.

Elucidating the adsorption of 2-Mercaptopyridine drug on the aluminum phosphide (Al12P12) nanocage: A DFT study.

Adsorption amplitude of the aluminum phosphide (Al12P12) nanocage toward the 2-Mercaptopyridine (MCP) drug was herein monitored based on density functional theory (DFT) calculations. The adsorption process through MCP⋅⋅⋅Al12P12 complex in various configurations was elucidated by means of adsorption (Eads) energies. According to the energetic affirmations, the Al12P12 nanocage demonstrated potential versatility toward adsorbing the MCP drug within the investigated configurations and exhibited significant negative adsorption energies up to -27.71 kcal/mol. Upon the results of SAPT analysis, the electrostatic forces showed the highest contributions to the overall adsorption process with energetic values up to -74.36 kcal/mol. Concurrently, variations of molecular orbitals distribution along with alterations in the energy gap (Egap) and Fermi level (EFL) of the studied nanocage were denoted after adsorbing the MCP drug. The favorable impact of water solvent within the MCP⋅⋅⋅Al12P12 complexes was unveiled and confirmed by negative solvation energy (ΔEsolv) values up to -17.75 kcal/mol. According to thermodynamic parameters, the spontaneous and exothermic natures of the considered adsorption process were proclaimed by negative values of ΔG and ΔH parameters. Significant changes in the IR and Raman peaks, along with the appearance of new peaks, were noticed, confirming the occurrence of the targeted adsorption process. Furthermore, the adsorption features of the MCP drug on the Al12N12 nanocage were elucidated and compared to the Al12P12 analog. The obtained results demonstrated the higher preferability of Al12P12 nanocage than the Al12N12 candidate towards adsorbing the MCP drug without structural distortion.

Adsorption of Molnupiravir anti-COVID-19 drug over B12N12 and Al12N12 nanocarriers: a DFT study.

The potentiality of B12N12 and Al12N12 nanocarriers to adsorb Molnupiravir anti-COVID-19 drug, for the first time, was herein elucidated using a series of quantum mechanical calculations. Density function theory (DFT) was systematically utilized. Interaction (Eint) and adsorption (Eads) energies showed higher negative values for Molnupiravir···Al12N12 complexes compared with Molnupiravir···B12N12 analogs. Symmetry-adapted perturbation theory (SAPT) results proclaimed that the adsorption process was predominated by electrostatic forces. Notably, the alterations in the distributions of the molecular orbitals ensured that the B12N12 and Al12N12 nanocarriers were efficient candidates for delivering the Molnupiravir drug. From the thermodynamic perspective, the adsorption process of Molnupiravir drug over B12N12 and Al12N12 nanocarriers had spontaneous and exothermic nature. The ESP, QTAIM, NCI, and DOS observations exposed the tendency of BN and Al12N12 to adsorb the Molnupiravir drug. Overall, these findings proposed that the B12N12 and Al12N12 nanocarriers are efficient aspirants for the development of the Molnupiravir anti-COVID-19 drug delivery process.Communicated by Ramaswamy H. Sarma.

Adsorption of Chlormethine Anti-Cancer Drug on Pure and Aluminum-Doped Boron Nitride Nanocarriers: A Comparative DFT Study.

The efficacy of pure and aluminum (Al)-doped boron nitride nanocarriers (B12N12 and AlB11N12) in adsorbing Chlormethine (CM), an anti-cancer drug, was comparatively dissected by means of the density functional theory method. The CM∙∙∙B12N12 and ∙∙∙AlB11N12 complexes were studied within two configurations, A and B, in which the adsorption process occurred via N∙∙∙ and Cl∙∙∙B/Al interactions, respectively. The electrostatic potential affirmations confirmed the opulent ability of the studied nanocarriers to engage in delivering CM via two prominent electrophilic sites (B and Al). Furthermore, the adsorption process within the CM∙∙∙AlB11N12 complexes was noticed to be more favorable compared to that within the CM∙∙∙B12N12 analog and showed interaction and adsorption energy values up to -59.68 and -52.40 kcal/mol, respectively, for configuration A. Symmetry-adapted perturbation theory results indicated that electrostatic forces were dominant in the adsorption process. Notably, the adsorption of CM over B12N12 and AlB11N12 nanocarriers exhibited predominant changes in their electronic properties. An elemental alteration was also revealed for the softness and hardness of B12N12 and AlB11N12 nanocarriers before and following the CM adsorption. Spontaneity and exothermic nature were obviously observed for the studied complexes and confirmed by the negative values of thermodynamic parameters. In line with energetic manifestation, Gibbs free energy and enthalpy change were drastically increased by the Al doping process, with values raised to -37.15 and -50.14 kcal/mol, respectively, for configuration A of the CM∙∙∙AlB11N12 complex. Conspicuous enhancement was noticed for the adsorption process in the water phase more than that in the gas phase and confirmed by the negative values of the solvation energy up to -53.50 kcal/mol for configuration A of the CM∙∙∙AlB11N12 complex. The obtained outcomes would be the linchpin for the future utilization of boron nitride as a nanocarrier.

Effect of External Electric Field on Tetrel Bonding Interactions in (FTF3···FH) Complexes (T = C, Si, Ge, and Sn).

A quantum chemical study was accomplished on the σ-hole interactions of the barely explored group IV elements, for the first time, in the absence and presence of the positively and negatively directed external electric field (EEF). The analyses of molecular electrostatic potential addressed the occurrence of the σ-hole on all the inspected tetrel atoms, confirming their salient versatility to engage in σ-hole interactions. MP2 energetic findings disclosed the occurrence of favorable σ-hole interactions within the tetrel bonding complexes. The tetrel bonding interactions became stronger in the order of C < Si < Ge < Sn for F-T-F3···FH complexes with the largest interaction energy amounting to -19.43 kcal/mol for the optimized F-Sn-F3···FH complex under the influence of +0.020 au EEF. The interaction energy conspicuously evolved by boosting the magnitude of the positively directed EEF value and declining the negatively directed EEF one. The decomposition analysis for the interaction energies was also executed in terms of symmetry-adapted perturbation theory, illuminating the dominant electrostatic contribution to all the studied complexes' interactions except carbon-based interactions controlled by dispersion forces. The outcomes that emerged from the current work reported significantly how the direction and strength of the EEF affect the tetrel-bonding interactions, leading to further improvements in the forthcoming studies of supramolecular chemistry and materials science.

Occult hepatitis B infection in egyptian chronic hepatitis C patients: prevalence, impact on pegylated interferon/ribavirin therapy.

BACKGROUND: Chronic HCV infection combined with occult hepatitis B infection has been associated with liver enzymes flare, advanced hepatic fibrosis and cirrhosis, poor response to standard interferon-α, and increased risk of HCC. This study aimed to elucidate the prevalence of occult hepatitis B infection in Egyptian chronic HCV patients, and to clarify its role in non-response of those patients to pegylated interferon/ribavirin therapy. This study enrolled 155 consecutive chronic HCV patients under pegylated interferon/ribavirin therapy. All patients were exposed to clinical assessment, biochemical, histological and virological examinations. HBV parameters (HBV DNA, anti-HBc, anti-HBs) and patients' response status to the combination therapy were determined. RESULTS: In this study, occult hepatitis B infection occurs in 3.9% of Egyptian chronic HCV patients; tends to affect younger age patients, associated with higher base line HCV viral load, less hepatic fibrosis than monoinfected patients. This occult hepatitis B infection is not a statistically significant cause of non-response to pegylated interferon/ribavirin therapy. Anti-HBs was not associated with any biochemical, histological or virological abnormalities in those patients, contrary to low response rate to therapy and higher HCV viral load that was observed with anti-HBc. CONCLUSIONS: Detection of HBV DNA in HBsAg negative chronic HCV patients plays a non significant role in non-response of Egyptian patients to pegylated interferon/ribavirin therapy.