Magnesium oxide nanoparticles, or MgO NPs, have garnered a lot of attention because of their exceptional stability, biocompatibility, and antibacterial properties. However, many of the green production methods used today have limited mechanistic knowledge and low reproducibility. In order to get over these challenges, we created a standardized and environmentally friendly process for producing MgO NPs using orange peel extract, a naturally occurring biowaste source rich in phytochemicals that acts as a stabilizing and reducing agent. Active precursor alteration during synthesis was clearly shown by X-ray diffraction (XRD) and thermal analysis (TGA-FTIR), while imaging techniques showed extremely crystalline cubic-phase MgO nanoparticles that were about 9 nm in size. The NPs displayed an irregular shape between 10 and 40 nm and a positive surface charge of +11.74 mV. Terpenoids, polymethoxyflavones, fatty acids, and sugars all work in collaboration with direct nucleation, regulate particle growth, and stabilize the nanoparticles, according to GC-MS analysis. The MgO NPs showed remarkable cytocompatibility in biology, preserving >80% viability in fibroblast and osteoblast cell lines while causing distinct metabolic regulation in osteoblasts without changing the shape of the cells. Consistent moderate activity against a variety of pathogens was confirmed by antimicrobial and antibiofilm assays, with special effectiveness against Gram-positive bacteria and Pseudomonas aeruginosa biofilms. This study shows that these MgO NPs have good biocompatibility and antimicrobial qualities, indicating the need for more research for possible biomedical applications. It also clarifies the molecular role of phytochemicals in nanoparticle formation and provides a repeatable green synthesis pathway.

The production of green nanomaterials has drawn considerable interest lately in the fields of tissue engineering and biomedicine. Thus, the environmentally friendly synthesis of ZnO and CuO nanoparticles (NPs) utilizing orange peel extract as a natural capping and reducing agent is the main focus of this study. Our comprehensive approach allows for a direct and systematic comparison of physicochemical attributes, biocompatibility, and antimicrobial activity under identical experimental circumstances, in contrast to other research that looked at individual nanoparticles under different conditions. The produced nanoparticles were characterized by techniques such as FTIR, XRD, SEM, TGA, and zeta potential assessment. MG-63 osteoblast-like cells, primary human dermal fibroblast BJ cells, and murine fibroblast L929 cells were used to evaluate biocompatibility using the MTT assay. The results showed dose-dependent cytotoxicity, especially above 25 µg/mL. Furthermore, both qualitative (growth inhibition zone diameter) and quantitative (minimum inhibitory concentration, MIC) techniques were used to assess the antimicrobial efficacy against Candida albicans and Gram-positive and Gram-negative bacteria. According to the obtained results, ZnO NPs showed broad-spectrum efficacy, whereas CuO NPs showed excellent antibacterial activity against Gram-positive bacteria (e.g., S. aureus, MIC = 0.313 μg/μL). The study highlights the potential of green-synthesized nanoparticles for utilization in biomedical applications, and it stresses the need for additional mechanistic research, including ROS measurement, to completely understand how they work.

The aim of the present study was to obtain, characterize, and evaluate the antioxidant potential of some extracts obtained from the bark of Betula alba var. pendula Roth., the root of Glycyrrhiza glabra L., and the green herb of the Avena sativa. The results revealed that the lowest IC50 value, determined by all three methods, was obtained for Betulae extractum (BE) (73.6 µg/mL—DPPH method, 11.2 µg/mL—ABTS method, and 58.7 µg/mL—FRAP method), followed by Liquiritiae extractum (LE) (805.6 µg/mL, 92.1 µg/mL, and 722 µg/mL) and Avenae extractum (1.13 mg/mL—DPPH method, 99.7 µg/mL—ABTS method, and 135.1 µg/mL—FRAP method). These results correlate with total polyphenols content (expressed in g tannic acid/100 g dry extract), with BE having more polyphenols than LE and AE (47.96 ± 9.7083 for BE, compared with 9.31 ± 0.9913 for LE and 40.55 ± 6.3715 for AE). The total flavonoid content (expressed as g rutoside/100 g dry extract) is similar for BE and LE (3.75 ± 0.3140 and 3.44 ± 0.3037) and smaller for AE (1.95 ± 0.0526). Therefore, Betulae extractum has the strongest antioxidant action, with an IC50 value very close to the standard used as a reference (ascorbic acid—16.5 μg/mL solution). The FT-ICR-MS analysis confirmed the presence of the major compounds in all three extracts. The antioxidant properties of the studied extracts were further supported by molecular docking experiments that revealed the potential of the analyzed phytochemicals to act as both noncovalent and covalent activators of the Nrf2 signaling pathway, with promising benefits in treating various skin disorders.

Currently, the treatment of wounds is still a challenge for healthcare professionals due to high complication incidences and social impacts, and the development of biocompatible and efficient medicines remains a goal. In this regard, mesoporous materials loaded with bioactive compounds from natural extracts have a high potential for wound treatment due to their nontoxicity, high loading capacity and slow drug release. MCM-41-type mesoporous material was synthesized by using sodium trisilicate as a silica source at room temperature and normal pressure. The synthesized mesoporous silica was characterized by using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), N₂ absorption–desorption (BET), Dynamic Light Scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR), revealing a high surface area (BET, 1244 m²/g); pore diameter of approx. 2 nm; and a homogenous, ordered and hexagonal geometry (TEM images). Qualitative monitoring of the desorption degree of the Salvia officinalis (SO) extract, rich in ursolic acid and oleanolic acid, and Calendula officinalis (CO) extract, rich in polyphenols and flavones, was performed via the continuous recording of the UV-VIS spectra at predetermined intervals. The active ingredients in the new composite MCM-41/sage and marigold (MCM-41/SO&CO) were quantified by using HPLC-DAD and LC-MS-MS techniques. The evaluation of the biological composites’ activity on the wound site was performed on two cell lines, HS27 and HaCaT, naturally involved in tissue-regeneration processes. The experimental results revealed the ability to stimulate collagen biosynthesis, the enzymatic activity of the main metalloproteinases (MMP-2 and MMP-9) involved in tissue remodeling processes and the migration rate in the wound site, thus providing insights into the re-epithelializing properties of mesoporous composites.