Ag nanoparticles (AgNPs) were biosynthesized using sage (Salvia officinalis L.) extract. The obtained nanoparticles were supported on SBA-15 mesoporous silica (S), before and after immobilization of 10% TiO₂ (Degussa-P25, STp; commercial rutile, STr; and silica synthesized from Ti butoxide, STb). The formation of AgNPs was confirmed by X-ray diffraction. The plasmon resonance effect, evidenced by UV-Vis spectra, was preserved after immobilization only for the sample supported on STb. The immobilization and dispersion properties of AgNPs on supports were evidenced by TEM microscopy, energy-dispersive X-rays, dynamic light scattering, photoluminescence and FT-IR spectroscopy. The antioxidant activity of the supported samples significantly exceeded that of the sage extract or AgNPs. Antimicrobial tests were carried out, in conditions of darkness and white light, on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Higher antimicrobial activity was evident for SAg and STbAg samples. White light increased antibacterial activity in the case of Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa). In the first case, antibacterial activity increased for both supported and unsupported AgNPs, while in the second one, the activity increased only for SAg and STbAg samples. The proposed antibacterial mechanism shows the effect of AgNPs and Ag⁺ ions on bacteria in dark and light conditions.

Nanocomposites containingTiO₂ and activated carbon were obtained by the sol-gel method in the presence of Brij 58 surfactant. The sample with a higher surface area (185.6 m²/g) was promoted with Fe by impregnating it with aqueous solution of Fe(NO₃)₃. The obtained iron loadings, measured using X-ray fluorescence, were 0.83%, 3.30% and 7.17%. TiO₂ anatase was identified in all the samples by X-ray diffraction and Raman spectroscopy, but the presence of iron oxides could not be detected. However, infrared spectroscopy indicated the existence of Fe-O and Fe-O-Ti bonds. X-ray photoelectron spectroscopy revealed the presence of Fe²⁺ for samples with a lower Fe content and a mixture of Fe²⁺ and Fe³⁺ in the sample with 7.17% Fe. UV-Vis and photoluminescence spectroscopy showed the presence of carbon and Fe alongside TiO₂. This combination led to new properties due to the generation of intermediate energy levels and defects, contributing to an enhancement in the photocatalytic performance. The highest photodegradation efficiency of Congo red in solution (84.46%) was obtained for the sample with 7.17% Fe under visible light irradiation and acidic conditions. The synergistic contribution of dye adsorption and photodegradation was demonstrated, taking into account ZPC values of nanocomposites. Kinetic studies were completed with reaction mechanisms based on the results obtained in the presence of scavengers.

The recent focus in the development of novel nanosystems for biomedical applications lays firmly on their interactions with biomolecules. Thermodynamic parameters driving the interaction between nanoparticles and proteins provide insights into complex processes at bio/nanointerface. The present work aims to investigate the binding mechanisms and the dominant contributions that determine the adsorption processes during the interactions of a model protein, that is, bovine serum albumin, with a new type of drug delivery systems, Vitamin E/sphingomyelin nanoemulsions, plain and coated with polyethylene glycol, and d‐ɑ‐tocopheryl polyethylene glycol succinate. The binding parameters (binding constant, binding stoichiometry, enthalpy, Gibbs energy, and entropy changes of binding) are evaluated by the isothermal titration calorimetry with a MicroCaliTC200 equipment. The effect of nanoemulsions on the protein stability is examined by measuring the thermodynamic parameters for the protein's unfolding (heat capacity; enthalpy, entropy, and free energy changes) with a NanoDSC (TA Instrument) apparatus. The thermodynamic profile shows for all compositions an entropy‐driven interaction dominated by hydrophobic forces due to the rearrangements/displacement of the surrounding water molecules, while maintaining the native conformation of the protein. All the information acquired by thermodynamic approach may significantly enhance the knowledge with special focus on PEGylated nanoemulsions used for biomedical applications.

This study focused on examining five synthesized 2-thiophene carboxylic acid thiourea derivatives that have significant pharmaceutical applications. These compounds exhibit antibacterial properties against both bacterial and fungal strains. In this study, density functional theory (DFT) calculations were performed, and the electronic properties of the investigated compounds, such as ionization potential, electron affinity, and electronic excitation energies, were calculated and compared to determine the beneficial features of these potential future medications. A vibrational analysis of the considered structures was performed, and the experimental FT-IR ATR spectra of the solid powders are presented.

This research focuses on the merocyanine form of a new synthesized spiroindolinonaphthoxazine compound. The merocyanine molecule (abbreviated as MC) has multiple fragments with different degrees of mobility. The conformational changes and the flexibility of MC in presence and in absence of the solvent molecules were studied by Molecular Dynamics simulations, providing insights into how they orient and interact with each other and with solvent molecules. The molecular packing of MC in presence and in absence of solvents with different polarities was thoroughly investigated in order to determine how the physicochemical interactions with the solvent influence the structure and stability of the MC molecule. Furthermore, the powders of MC obtained from its solutions in water, methanol, ethanol, and acetonitrile were experimentally characterized using differential scanning calorimetry, thermogravimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Both calculations and experimental results reveal the effect of the solvent polarity on the dissolved MC molecule.

This research focuses on the merocyanine (MC) form of a spiroindolinonaphthoxazine compound whose IUPAC signature is 4‐[(2E)‐1,1‐dimethyl‐2‐({[(1Z)‐2‐oxo‐1,2‐dihydronaphthalen‐1‐ylidene]amino}methylidene)‐1H,2H,3H‐benzo[e]indol‐3‐yl]butane‐1‐sulfonic acid. The MC molecule has multiple fragments with different degrees of mobility. The conformational changes and the flexibility of MC in presence and in absence of the solvent molecules were studied by Annealing-Molecular Dynamics (MD) cycles, providing insights into how they orient and interact with each other and with solvent molecules. The molecular packing of MC in presence and in ab-sence of solvents with different polarities was thoroughly investigated in order to determine, how the physicochemical interactions with the solvent influence the structure and stability of the MC molecule. Furthermore, the powders of MC obtained from its solutions in water, methanol, ethanol and acetonitrile were experimentally characterized using differential scanning calorimetry, thermogravimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Both calculations and experimental results reveal the effect of the solvent polarity on the dissolved MC molecule.