In this paper, novel drug delivery systems (DDS) were designed based on graphene oxide (GO) as nanocarrier, loaded with two natural substances (quercetin (Qu) and juglone (Ju)) at different concentrations. The chemical structure and morphology of the synthesized GO-based materials were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Raman spectroscopy. The antibacterial activity was evaluated against standard strains, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 8739, and Candida albicans ATCC 10231. Results demonstrated excellent antimicrobial activity, with a 5 log reduction of E. coli and a 1 log to 3.04 log reduction of S. aureus populations. Reduction rates were above 90%. Biocompatibility tests were also performed on GO-based materials, and the results showed biocompatible behavior for both L929 fibroblast cell line and BT474 breast cancer cells at lower concentrations. The identity of Qu and Ju was demonstrated by matrix-assisted laser desorption/ionization (MALDI) analysis, showing the compounds’ mass with high accuracy. In addition, specific properties of GO made it a versatile matrix for the MALDI analysis. The results of this study indicated that GO-based platforms may be suitable for applications in many areas for the effective and beneficial use of hydrophobic compounds such as Ju and Qu.

New N-acyl thiourea derivatives with heterocyclic rings have been synthesized by first obtaining isothiocyanate, which further reacted with a heterocyclic amine, characterized by (FT-IR, NMR spectroscopy and FT-ICR) and tested for their in vitro antimicrobial, anti-biofilm and antioxidant activities to obtain a drug candidate in a lead-optimization process. From the tested compounds, those bearing benzothiazole (1b) and 6-methylpyridine (1d) moieties revealed anti-biofilm activity against E. coli ATCC 25922 at MBIC values of 625 µg/mL. Compound 1d exhibited the highest antioxidant capacity (~43%) in the in vitro assay using 1,1-diphenyl-2-picrylhydrazyl (DPPH). Considering the in vitro results, the highest anti-biofilm and antioxidant activities were obtained for compound 1d. Therefore, a reversed-phase high-performance liquid chromatography (RP-HPLC) method has been optimized and validated for the quantitative determination of compound 1d. The detection and quantitation limits were 0.0174 μg/mL and 0.0521 μg/mL, respectively. The R² correlation coefficient of the LOQ and linearity curves were greater than 0.99, over the concentration range of 0.05 μg/mL–40 μg/mL. The precision and accuracy of the analytical method were within 98–102%, confirming that the method is suitable for the quantitative determination of compound 1d in routine quality control analyses. Evaluating the results, the promising potential of the new N-acyl thiourea derivatives bearing 6-methylpyridine moiety will be further investigated for developing agents with anti-biofilm and antioxidant activities.

Since medicinal plants are widely used in treating various diseases, phytoconstituents enrichment strategies are of high interest for plant growers. First of all, we investigated the impact of phytosociological cultivation on polyphenolic content (total flavonoids—TFL, and total polyphenols—TPC) of peppermint (Mentha piperita L.) and lemon balm (Melissa officinalis L.) leaves, using spectrophotometric methods. Secondly, the influence of chemical (NPK) and organic (BIO) fertilization on polyphenolic content and plant material quality was also assessed. Dry extracts were obtained from harvested leaves using hydroethanolic extraction solvents for further qualitative and quantitative assessment of phytoconstituents by FT-ICR MS and UHPLC-MS. Furthermore, the antioxidant activity of leaf extracts was determined in vitro using DPPH, ABTS and FRAP methods. Molecular docking simulations were employed to further evaluate the antioxidant potential of obtained extracts, predicting the interactions of identified phytochemicals with sirtuins. The concentration of polyphenols was higher in the plant material harvested from the phytosociological culture. Moreover, the use of BIO fertilizer led to the biosynthesis of a higher content of polyphenols. Higher amounts of phytochemicals, such as caffeic acid, were determined in extracts obtained from phytosociological crops. The antioxidant activity was dependent on polyphenols concentration, more potent inhibition values being observed for the extracts obtained from the phytosociological batches. Molecular docking studies and MM/PBSA calculations revealed that the obtained extracts have the potential to directly activate sirtuins 1, 5 and 6 through several polyphenolic compounds, such as rosmarinic acid, thus complementing the free radical scavenging activity with the potential stimulation of endogenous antioxidant defense mechanisms. In conclusion, growing medicinal plants in phytosociological cultures treated with biofertilizers can have a positive impact on plant material quality, concentration in active constituents and biological activity.

Oxidative stress is the most critical factor in multiple functional disorders’ development, and natural antioxidants could protect the human body against it. Our study aims to investigate the polyphenol content of four extracts of two medicinal plants (Rosmarinus officinalis L. and Thymus vulgaris L.) and analyze the correlation with their antioxidant activity. The research was carried out on extracts of rosemary and thyme obtained from species cultivated together in plant communities. Both were compared with extracts from species cultivated in individual crops (control crops). Their polyphenols were determined by spectrophotometric methods (dosage of flavones, phenol carboxylic acids, and total polyphenols) and chromatography (UHPLC–MS and FT–ICR MS). Triterpenic acids were also quantified, having a higher concentration in the thyme extract from the culture. The antioxidant activity of the dry extracts was evaluated in vitro (DPPH, ABTS, and FRAP) and in silico (prediction of interactions with BACH1/BACH2 transcription factors). The concentrations of polyphenols are higher in the extracts obtained from the sources collected from the common crops. These observations were also validated following the chromatographic analysis for some compounds. Statistically significant differences in the increase in the antioxidant effect were observed for the extracts from the common batches compared to those from the individual ones. Following the Pearson analysis, the IC₅₀ values for each plant extract were strongly correlated with the concentration of active phytoconstituents. Molecular docking studies revealed that quercetin could bind to BTB domains of BACH1 and BACH2 transcription factors, likely translating into increased antioxidant enzyme expression. Future studies must validate the in silico findings and further investigate phytosociological cultivation’s effects.

This study’s main objective was to fabricate an innovative three-dimensional microfluidic platform suitable for well-controlled chemical syntheses required for producing fine-tuned nanostructured materials. This work proposes using vortex mixing principles confined within a 3D multilayered microreactor to synthesize magnetic core-shell nanoparticles with tailored dimensions and polydispersity. The newly designed microfluidic platform allowed the simultaneous obtainment of Fe₃O₄ cores and their functionalization with a salicylic acid shell in a short reaction time and under a high flow rate. Synthesis optimization was also performed, employing the variation in the reagents ratio to highlight the concentration domains in which magnetite is mainly produced, the formation of nanoparticles with different diameters and low polydispersity, and the stability of colloidal dispersions in water. The obtained materials were further characterized by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM), with the experimental results confirming the production of salicylic acid-functionalized iron oxide (Fe₃O₄-SA) nanoparticles adapted for different further applications.

Chronic venous disease is one of the most common vascular diseases; the signs and symptoms are varied and are often neglected in the early stages. Vascular damage is based on proinflammatory, prothrombotic, prooxidant activity and increased expression of several matrix metalloproteinases (MMPs). The aim of this research is preparation and preliminary characterization of three vegetal extracts (Sophorae flos-SE, Ginkgo bilobae folium-GE and Calendulae flos-CE). The obtained dry extracts were subjected to phytochemical screening (FT-ICR-MS, UHPLC-HRMS/MS) and quantitative analysis (UHPLC-HRMS/MS, spectrophotometric methods). Antioxidant activity was evaluated using three methods: FRAP, DPPH and ABTS. More than 30 compounds were found in each extract. The amount of flavones follows the succession: SE > GE > CE; the amount of phenolcarboxylic acids follows: SE > CE > GE; and the amount of polyphenols follows: SE > GE > CE. Results for FRAP method varied as follows: SE > CE > GE; results for the DPPH method followed: SE > GE > CE; and results for ABTS followed: SE > GE > CE. Strong and very strong correlations (appreciated by Pearson coefficient) have been observed between antioxidant activity and the chemical content of extracts. Molecular docking studies revealed the potential of several identified phytochemicals to inhibit the activity of four MMP isoforms. In conclusion, these three extracts have potential in the treatment of chronic venous disease, based on their phytochemical composition.