Cytotoxicity, antifungal, antioxidant, antibacterial and photodegradation potential of silver nanoparticles mediated via Medicago sativa extract

The biosynthesis of metallic nanoparticles is on a sharp rise as they have growing applications in environmental and biomedical sciences. This study reports an eco-friendly and cost-effective methodology for synthesizing biogenic silver nanoparticles (AgNPs) using the extract of Medicago sativa (M. sativa) cultivated in South Khorasan. The parameters used in the synthesis process were optimized to obtain uniformly distributed AgNPs in suitable sizes. The morphological, structural, and bonding characteristics of M. sativa extract-based AgNPs (MSE-AgNPs) were explored using FTIR, FESEM, EDS, TEM, XRD, UV–Vis, and DLS techniques. UV–Vis spectroscopy confirmed the formation of MSE-AgNPs by observing the typical surface plasmon resonance (SPR) peak at 419 nm. XRD, FESEM, TEM, and DLS analyses confirmed the formation of face-centered cubic (fcc) crystalline structure, spherical/elliptical morphology, the average particle size of 15–35 nm, and highly stable MSE-AgNPs. Green synthesized MSE-AgNPs indicated a significant antioxidant activity (78%) compared to M. sativa extract (32%). As such, the synthesized MSE-AgNPs revealed a potential antioxidant activity towards the DPPH radicals. The biologically synthesized MSE-AgNPs exhibited highly potential antibacterial and antifungal activities against Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Staphylococcus epidermidis, Enterococcus faecalis, Staphylococcus aureus, and Candida albicans with the minimum inhibitory concentration (MIC) values of 62.5, 125, 125, 1000, 125, 1000, and 31.25 µg/mL, respectively. In vitro cytotoxicity of the MSE-AgNPs against human fibroblast (HF) cells indicated a dose–response activity (with IC50 value of 18 µg/mL). Moreover, the AgNPs revealed efficient photocatalytic degradation of thymol blue (TB) as an anionic dye and malachite green (MG) as a cationic dye under sunlight and UV irradiations. Up to 94.37% and 90.12% degradation rates were obtained for MG and TB within only 100 min of UV irradiation. These observations signify that synthesized MSE-AgNPs can have great potential for biological and environmental applications

Typology and dynamics of actors’ roles and positions within entrepreneurial ecosystems:an exploratory study

Abstract This study explores how health-tech small and mid-size enterprises (SMEs) could better utilize the entrepreneurial ecosystems (EEs) around them in developing their business within this fast-growing yet under-researched industry. Based on the qualitative empirical study, we examine actor roles and related dynamics in the health-tech ecosystem to understand how firms could benefit from the ecosystem’s resources. The study contributes to EE research by providing an empirically grounded typology of ten actor roles and examining how an individual company could change and develop its role in the network to grow and succeed. Moreover, it extends the current research on role typologies by explaining the various roles in EEs and underlines the importance of ecosystem dynamics. Managerially, the study highlights the importance of recognizing the company’s role(s) and the roles of other ecosystem members, which further aids in their strategic decision-making and future planning

Aesculus hippocastanum extract-mediated biosynthesis of silver-decorated zinc oxide nanoparticles and investigation of their photocatalytic, antibacterial, and antioxidant properties

In this research, silver-decorated zinc oxide nanoparticles (ZnO–Ag NPs) were fabricated using Aesculus hippocastanum fruit extract (ZnO–Ag@AHFE NPs), and their catalytic and antimicrobial properties were studied. The nanoparticles were identified using XRD, TEM, and FT-IR analyses, which confirmed their spherical morphology, uniform structure, and particle sizes ranging from 50 to 70 nm. The ZnO–Ag@AHFE NPs illustrated high antibacterial performance compared to the extract and ZnO NPs alone, achieving a minimum inhibitory concentration (MIC) of 125 µg/mL against Escherichia coli and Pseudomonas aeruginosa. Additionally, the ZnO–Ag@AHFE NPs exhibited outstanding photocatalytic efficiency, degrading methylene blue and rhodamine B dyes by 97.6% and 94.3%, respectively, surpassing the performance of other catalysts. Antioxidant assays revealed that the nanoparticles inhibited 85% of DPPH free radicals, underscoring their potential in biological applications. This study presents a green method using A. hippocastanum fruit extract, offering an innovative approach to enhance the antibacterial, catalytic, and antioxidant properties of ZnO–Ag NPs. These findings highlight the transformative potential of green synthesis strategies for the development of multifunctional nanomaterials

A facile green synthesis route to novel MgO-Ag nanoparticles using Pistacia atlantica leaf extract (MgO-Ag@PALE NPs) and its photocatalytic and antibacterial activity

In recent years, the utilization of a cost-effective and environmentally friendly approach for synthesizing nanoparticles for environmental and biomedical applications has gained significant importance. To achieve this objective, MgO-Ag nanoparticles were synthesized using Pistacia atlantica leaf extract (MgO-Ag@PALE NPs). Characterization through FESEM, FT-IR, TEM, and XRD analyses confirmed the morphology, size, and purity of the synthesized nanoparticles. XRD analysis affirmed the absence of impurities in both pure MgO and MgO-Ag@PALE NPs. The TEM and FESEM results showed a stone-like morphology with sizes ranging from approximately 70 to 80 nm. Antibacterial efficacy against five standard bacteria strains was evaluated using the broth micro-dilution method. The green synthesized MgO-Ag@PALE NPs demonstrated remarkable antibacterial properties, particularly against Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterococcus faecalis, with a minimum inhibitory concentration (MIC) of 250 µg/ml. The photocatalytic potential of both pure MgO and MgO-Ag@PALE NPs was assessed for the degradation of industrial effluents (rhodamine B and methylene blue) under UV light exposure. The biosynthesized MgO-Ag@PALE NPs exhibited a degradation rate of 94.32% for rhodamine B and 97.63% for methylene blue, highlighting their efficacy as nanocatalysts in photocatalytic applications. Meanwhile, the degradation percentage of rhodamine B and methylene blue pollutants for pure MgO nanoparticles was 88.64% and 90.41%, respectively. The results indicated that the doping of silver nanoparticles on magnesium oxide using Pistacia atlantica leaf extract can significantly enhance the degradation of pollutants. Consequently, our study demonstrates that MgO-Ag@PALE NPs can be highly beneficial in biomedicine and the purification of industrial pollutants

Photochemical synthesis of metallic silver nanoparticles using Pistacia khinjuk leaves extract (PKL@AgNPs) and their applications as an alternative catalytic, antioxidant, antibacterial, and anticancer agents

In recent decades, antimicrobial resistance of different bacteria against various antibiotics and contamination of water resources by various dyes has been one of the most important human problems. Therefore, in this research, biogenic silver nanoparticles were synthesized using nontoxic and rapid approach using Pistacia khinjuk leaves extract (P. khinjuk) as compatible and safe reducing agent (PKL@AgNPs). Nanoparticle optimization experiments were performed at different times, temperatures and concentrations in order to achieve the most optimal conditions. The biosynthesized AgNPs were characterized in terms crystalline, morphology and structural. The Fourier-transform infrared spectroscopy (FT-IR) spectra showed that the phenol compounds present in the P. khinjuk leaves extract were responsible for silver ion (Ag+) reduction and stabilization of AgNPs (Ag0). X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) analysis results revealed that the product were face-centered cubic structure, homogeneous, uniformly, oval-like and spherical morphology with size of about 35–45 nm. The biosynthesized AgNPs exhibited a high photocatalytic activity for the degradation of the methylene blue (MB) and methyl orange (MO) as hazardous contaminants. The degradation efficiency of PKL@AgNPs for MB and MO pollutants were 93.2% and 85.37% under UV and 75.18% and 70.03% under sun-light irradiations, respectively. Furthermore, the PKL@AgNPs showed strong antibacterial and antifungal activities against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Streptococcus mutans, Streptococcus mitis, Enterococcus faecalis, and Candida albicans with minimum inhibitory concentration (MIC) values of 0.58, 0.58, 0.58, 1.17, 2.34, 1.17, and 0.15 μg ml−1, respectively. The antioxidant activity of PKL@AgNPs was calculated and the results revealed that the percentage of DPPH inhibition increased (3.8% to 69.9%) with increasing the concentration of nanoparticles. Also, the PKL@AgNPs also revealed significant anticancer activity on k562 as a human leukemia cancer cell line (IC50 = 2.69 μg ml−1). All these investigations revealed that silver nanoparticles synthesized by natural extract have the potential to use as low-cost and efficient nanoparticles for environmental and biomedical applications