Green synthesis of cerium oxide nanoparticles usingTribulus terrestris: characterization and evaluation of antioxidant, anti-inflammatory and antibacterial efficacy against wound isolates.

Multi-drug resistance (MDR) infections are a significant global challenge, necessitating innovative and eco-friendly approaches for developing effective antimicrobial agents. This study focuses on the synthesis, characterization, and evaluation of cerium oxide nanoparticles (CeO2NPs) for their antioxidant, anti-inflammatory, and antibacterial properties. The CeO2NPs were synthesized using aTribulus terrestrisaqueous extract through an environmentally friendly process. Characterization techniques included UV-visible spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), x-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Energy Dispersive x-ray (EDX) analysis. The UV-vis spectroscopy shows the presence of peak at 320 nm which confirms the formation of CeO2NPs. The FT-IR analysis of the CeO2NPs revealed several distinct functional groups, with peak values at 3287, 2920, 2340, 1640, 1538, 1066, 714, and 574 cm-1. These peaks correspond to specific functional groups, including C-H stretching in alkynes and alkanes, C=C=O, C=C, alkanes, C-O-C, C-Cl, and C-Br, indicating the presence of diverse chemical bonds within the CeO2NPs. XRD revealed that the nanoparticles were highly crystalline with a face-centered cubic structure, and SEM images showed irregularly shaped, agglomerated particles ranging from 100-150 nm. In terms of biological activity, the synthesized CeO2NPs demonstrated significant antioxidant and anti-inflammatory properties. The nanoparticles exhibited 82.54% antioxidant activity at 100 μg ml-1, closely matching the 83.1% activity of ascorbic acid. Additionally, the CeO2NPs showed 65.2% anti-inflammatory activity at the same concentration, compared to 70.1% for a standard drug. Antibacterial testing revealed that the CeO2NPs were particularly effective against multi-drug resistant strains, includingPseudomonas aeruginosa,Enterococcus faecalis, and MRSA, with moderate activity againstKlebsiella pneumoniae. These findings suggest that CeO2NPs synthesized viaT. terrestrishave strong potential as antimicrobial agents in addressing MDR infections.

Choudary MRP ，Surya M ，Saravanan M 《Biomedical Physics & Engineering Express》

Characterization, anti-microbial, anti-oxidant and growth promoting effects of biogenically synthesized silver nanoparticles derived from Dicliptera bupleuroides Nees.

Samad M ，Akhtar W ，Muneer A ，Fatima I ，Manzoor M ，Gillani SW ，Rehman FU ，Majeed K ，Ali B ，Sarwar R ... -  《-》

Antimicrobial efficiency against fish pathogens on the green synthesized silver nanoparticles.

Fish-borne pathogens such as A. hydrophila and F. aquidurense are the most resistant strains in pisciculture farming. Removing the aforementioned pathogens without antibiotics presents a formidable challenge. To overcome this problem, silver nanoparticles (AgNPs) are synthesized using silver nitrate, water medium, and as an AzadirachtaIndica leaf extract via the green synthesis route. X-ray diffraction (XRD) pattern results authenticate the synthesized material is the face-centered cubic structure of silver. The optical absorption edge of the synthesized product was found at the wavelength of 440 nm from the UV-visible spectra, which is confirmed to relate to the Surface Plasmon Resonance peaks of silver particles. In addition, the optical band gap value of the synthesized Ag sample is measured to be 2.81 eV from the obtained optical absorption spectra. EDX spectrum of the synthesized product also supports confirming the silver particle formation. The FT-IR spectra of the neem extract and silver nanoparticles showed their characteristic functional groups, respectively. The presence of bands between 1000 cm-1 to 500 cm-1 indicates to the formation of silver particles. Spherical particles appeared in the synthesized Ag using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The particle size of Ag NPs was measured as 40 nm and 62 ± 10 nm by TEM and Dynamic Light Scattering (DLS). The zeta potential was also measured as -12 mV showing the synthesized sample's stable nature. Using the DPPH assay, synthesized AgNPs were taken along with the various concentrations of ascorbic acid (20, 40, 60, 80, and 100 μg/mL) to examine the free radical scavenging activity (RSA). RSA value is higher (84 ± 2 %) for synthesized AgNPs at higher concentration (100 μg/mL) than 21 ± 2 % at low concentration (100 μg/mL). The antimicrobial efficacy of the AgNPs against A. hydrophila and F. aquidurense was performed through the agar diffusion method and its results showed the inhibitory zones of the F.aquidurense and A. hydrophila were measured as 25 ± 3 mm, and 28 ± 4 mm respectively. The synthesized Ag particles showed excellent antimicrobial and antioxidant properties confirmed by antimicrobial and DPPH experiments. It implies that the green synthesized silver nanoparticles could be a good alternative for antibiotics in aquaculture farms. The exposure of low concentrations of silver nanoparticles to zebrafish and brine shrimp does not affect the viability and morphology. The exposure of silver nanoparticles in the fisheries in optimized concentration and time could control the fish-borne pathogens without antibiotics.

Ramya JR ，Ali S ，K TA ，Vijayalakshmi R ，Gajendiran J ，Gnanam S ，Ramachandran K ... -  《-》

Antibacterial efficacy of silver nanoparticles against multi-drug resistant clinical isolates from post-surgical wound infections.

In order to investigate new effective and inexpensive nano-therapeutic approach for P. aeruginosa, staphylococcus aureus and coagulase negative staphylococci (CoNS), the present study reports an eco-friendly process for rapid synthesis of silver nanoparticles (Ag-NPs) using aqueous leaf extract of Corchorus Capsularis (CRCP). Formation of stable Ag-NPs at different time intervals gives mostly spherical particles with diameters ranging from 5 to 45 nm. The resulting Ag-NPs were characterized using Ultraviolet visible (UV-Vis) spectroscopy, Fourier Transform Infrared (FT-IR) spectroscopy, X-Ray Diffraction (XRD) analysis, Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray analysis (EDX). XRD study shows that the particles are crystalline in nature with face centered cubic geometry. TEM studies show the formation of Ag-NPs with average size of 20.52 nm. The antimicrobial activity of the synthesized Ag-NPs was investigated against multi drug resistant (MDR) P. aeruginosa, Staphylococcus aureus and CoNS isolates from post-surgical wound infections. The present study suggests that Ag-NPs synthesized from aqueous leaf extract of CRCP shows significant antibacterial potential against MDR isolates from post-surgical wound infections.

Kasithevar M ，Periakaruppan P ，Muthupandian S ，Mohan M ... -  《-》

Green Synthesis of Molybdenum Nanoparticles From Solanum xanthocarpum and Evaluation of Their Antimicrobial and Antioxidant Activity Against Multidrug-Resistant Wound Isolates.

In recent years, antimicrobial drug resistance has emerged as a serious global public health concern, according to the World Health Organization data. The emergence of pathogens resistant to multiple drugs has been linked to an increase in morbidity and mortality from microbial infections. The study's main goal is to explore the efficacy of using Solanum xanthocarpum in the green synthesis of molybdenum nanoparticles (Mo NPs) for antibacterial and antioxidant properties. An eco-friendly method of synthesizing Mo NPs was accomplished using an aqueous extract of Solanum xanthocarpum. Characterization of the synthesized nanoparticles was done by UV-visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). After that, antibacterial and antioxidant activity was further evaluated. The UV-visible spectrophotometer analysis confirmed the presence of synthesized Mo NPs showing a peak around 320 nm. The presence of functional compounds like C-CI, C-H, C=C, and O=C=O was confirmed by FT-IR spectrum analysis. The positions of diffraction peaks in Mo NP patterns were identified using XRD analysis; they were more crystalline (82.7%) and less amorphous (17.3%). The presence of the elements molybdenum (Mo), carbon (C), and oxygen (O) was confirmed by the EDX spectrum and irregular shapes shown in the SEM images. Further, the antimicrobial study results showed the formation of an inhibition zone against 27 mm for Klebsiella pneumoniae, 24 mm for Pseudomonas aeruginosa, 22 mm for Staphylococcus aureus, and 24 mm for Enterococcus faecalis, respectively, at a high concentration 80 μg/ml of Mo NPs. The maximum antioxidant activity at 100 μg/ml was 73.49%, compared to the standard ascorbic acid (74.25%). Additionally, the moderate activity at 60 μg/ml was 53.21%, compared to the standard (56.5%), and the minimal activity at 20 μg/ml was 30.21%, compared to the standard (36.89%). The environmentally friendly synthesized Mo NPs from Solanum xanthocarpum exhibited antioxidant activity. Furthermore, the findings show that Mo NPs mediated by Solanum xanthocarpum can inhibit antibiotic-resistant bacteria, especially methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Enterococcus faecalis. In order to understand further how nanoparticles work against bacteria that are resistant to many drugs, additional research and clinical studies would be needed.

Bharathidasan P ，Surya M ，Geetha Sravanthy P ，Saravanan M ... -  《Cureus》