Bionanotechnology is the combination of biotechnology and nanotechnology for the development of biosynthetic and environmentally friendly nanomaterial synthesis technology. The presented research work adopted a reliable and environmentally sustainable approach to manufacturing silver nanoparticles from Brachychiton populneus (BP-AgNPs) leaf extract in aqueous medium. The Brachychiton populneus-derived silver nanoparticles were characterized by UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). In addition, the antioxidant, anti-inflammatory, antidiabetic, and cytotoxic activities of AgNPs were brought to light. The synthesis of BP-AgNPs was verified at 453 nm wavelength by UV–Vis spectrum. FTIR analysis revealed that synthesis, stability, and capping of AgNPs depend on functional groups such as alkane, alkene, nitro, flouro, phenol, alcoholic, and flavones, present in plant extract. The SEM analysis revealed evenly distributed cubical-shaped nanoparticles. The average diameter of AgNPs was 12 nm calculated from SEM image through ImageJ software. EDX spectrum confirmed the presence of Ag at 3 keV and other trace elements such as oxygen and chlorine. The biosynthesized silver nanoparticles exhibited proven antioxidant (DPPH assay), antidiabetic (alpha amylase assay), anti-inflammatory (albumin denaturation assay), and cytotoxic (MTT assay) potential against U87 and HEK293 cell lines in comparison to standard drugs. In these assays, BP-AgNPs exhibited inhibition in a concentration-dependent manner and had lower IC₅₀ values compared to standards. All these outcomes suggest that silver nanoparticles work as a beneficial biological agent. The salient features of biosynthesized silver nanoparticles propose their effective applications in the biomedical domain in the future.

In this study, the antibacterial and antifungal properties of silver nanoparticles synthesized with the aqueous plant extract of Acer oblongifolium leaves were defined using a simplistic, environmentally friendly, reliable, and cost-effective method. The aqueous plant extract of Acer oblongifolium, which served as a capping and reducing agent, was used to biosynthesize silver nanoparticles. UV visible spectroscopy, X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and scanning electron microscopy were used to analyze the biosynthesized Acer oblongifolium silver nanoparticles (AgNPs). Gram-positive bacteria (Bacillus paramycoides and Bacillus cereus) and Gram-negative bacteria (E. coli) were used to test the AgNPs’ antibacterial activity. The presence of different functional groups was determined by FTIR. The AgNPs were rod-like in shape. The nanoparticles were more toxic against Escherichiacoli than both Bacillus cereus and Bacillus paramycoides. The AgNPs had IC₅₀ values of 6.22 and 9.43 and mg/mL on HeLa and MCF-7, respectively, proving their comparatively strong potency against MCF-7. This confirmed that silver nanoparticles had strong antibacterial activity and antiproliferative ability against MCF-7 and HeLa cell lines. The mathematical modeling revealed that the pure nanoparticle had a high heat-absorbing capacity compared to the mixed nanoparticle. This research demonstrated that the biosynthesized Acer oblongifolium AgNPs could be used as an antioxidant, antibacterial, and anticancer agent in the future.

Herein, we report the synthesis of eight new mononuclear and binuclear Co²⁺, Ni²⁺, Cu²⁺, and Zn²⁺ methoxy thiosemicarbazone (MTSC) complexes aiming at obtaining thiosemicarbazone complex with potent biological activity. The structure of the MTSC ligand and its metal complexes was fully characterized by elemental analysis, spectroscopic techniques (NMR, FTIR, UV-Vis), molar conductivity, thermogravimetric analysis (TG), and thermal differential analysis (DrTGA). The spectral and analytical data revealed that the obtained thiosemicarbazone-metal complexes have octahedral geometry around the metal center, except for the Zn²⁺-thiosemicarbazone complexes, which showed a tetrahedral geometry. The antibacterial and antifungal activities of the MTSC ligand and its (Co²⁺, Ni²⁺, Cu²⁺, and Zn²⁺) metal complexes were also investigated. Interestingly, the antibacterial activity of MTSC- metal complexes against examined bacteria was higher than that of the MTSC alone, which indicates that metal complexation improved the antibacterial activity of the parent ligand. Among different metal complexes, the MTSC- mono- and binuclear Cu²⁺ complexes showed significant antibacterial activity against Bacillus subtilis and Proteus vulgaris, better than that of the standard gentamycin drug. The in silico molecular docking study has revealed that the MTSC ligand could be a potential inhibitor for the oxidoreductase protein.

Twenty-four analogues of benzimidazole-based thiazoles (1–24) were synthesized and assessed for their in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory potential. All analogues were found to exhibit good inhibitory potential against cholinesterase enzymes, having IC₅₀ values in the ranges of 0.10 ± 0.05 to 11.10 ± 0.30 µM (for AChE) and 0.20 ± 0.050 µM to 14.20 ± 0.10 µM (for BuChE) as compared to the standard drug Donepezil (IC₅₀ = 2.16 ± 0.12 and 4.5 ± 0.11 µM, respectively). Among the series, analogues 16 and 21 were found to be the most potent inhibitors of AChE and BuChE enzymes. The number (s), types, electron-donating or -withdrawing effects and position of the substituent(s) on the both phenyl rings B & C were the primary determinants of the structure-activity relationship (SAR). In order to understand how the most active derivatives interact with the amino acids in the active site of the enzyme, molecular docking studies were conducted. The results obtained supported the experimental data. Additionally, the structures of all newly synthesized compounds were elucidated by using several spectroscopic methods like ¹³C-NMR, ¹H-NMR and HR EIMS.

The widespread and indiscriminate use of broad-spectrum antibiotics leads to microbial resistance, which causes major problems in the treatment of infectious diseases. However, advances in nanotechnology have opened up new domains for the synthesis and use of nanoparticles against multidrug-resistant pathogens. The traditional approaches for nanoparticle synthesis are not only expensive, laborious, and hazardous but also have various limitations. Therefore, new biological approaches are being designed to synthesize economical and environmentally friendly nanoparticles with enhanced antimicrobial activity. The current study focuses on the isolation, identification, and screening of metallotolerant fungal strains for the production of silver nanoparticles, using antimicrobial activity analysis and the characterization of biologically synthesized silver nanoparticles by X-ray diffraction (XRD) spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and scanning electron microscopy (SEM). In total, 11 fungal isolates were isolated and screened for the synthesis of AgNPs, while the Penicillium notatum (K1) strain was found to be the most potent, demonstrating biosynthetic ability. The biologically synthesized silver nanoparticles showed excellent antibacterial activity against the bacteria Escherichia coli (ATCC10536), Bacillus subtilis, Staphylococcus aureus (ATCC9144), Pseudomonas aeruginosa (ATCC10145), Enterococcus faecalis, and Listeria innocua (ATCC13932). Furthermore, three major diffraction peaks in the XRD characterization, located at the 2θ values of 28.4, 34.8, 38.2, 44, 64, and 77°, confirmed the presence of AgNPs, while elemental composition analysis via EDX and spherical surface topology with a scanning electron microscope indicated that its pure crystalline nature was entirely composed of silver. Thus, the current study indicates the enhanced antibacterial capability of mycologically synthesized AgNPs, which could be used to counter multidrug-resistant pathogens.

Coronavirus disease-19 (COVID-19) is a highly contagious infection that mainly affects the respiratory system of patients. To date, more than 10 million people have been affected by this virus, and Saudi Arabia has also reported over 210 million cases. At present, there is no established treatment for COVID-19. Vaccination is one of the ways to defeat the pandemic. Recent reports have indicated rare but serious adverse events after vaccination, causing an anxious response from the general public worldwide. Therefore, this study was aimed at evaluating the knowledge, attitude, and perception of the COVID-19 vaccine among the Saudi population. This study is a cross-sectional, web-based online survey conducted using a snowball sampling technique. A self-administered questionnaire prepared in Arabic and English was used to collect feedback from the general population on their knowledge, attitudes, and perceptions about the COVID-19 vaccine. Participants (n = 2022) from different regions of the country replied to the questions. The responses to the questions were recorded on a spreadsheet and analyzed using the SPSS software. Statistical analysis was performed using one-way ANOVA and non-parametric tests to draw conclusions about the results. Multivariate stepwise regression analysis was performed to determine the association between the knowledge, attitude, and perception scores and the demographic variables. p < 0.05 was used to indicate the significance of the data. The data from the study indicated that most of the participants were males (81%), between 18 and 59 years of age (85.9%), Saudi nationals (98.3%), and possessed graduation or above as a qualification (62.9%). The results suggest that a major portion of respondents have satisfactory knowledge (76%), a positive attitude (72.4%), and perception (71.3%) towards the use of COVID-19 vaccines. Their responses can be categorized as between ‘good’ and ‘fair’. However, 30–40% of respondents lacked information about COVID-19 vaccination availability for under 18-year-olds as well as for pregnant women, in addition to the lack of knowledge about the serious unreported adverse reactions and long-term protection offered by the vaccine against coronavirus. The correlation analysis between the variables (p > 0.05) indicated that the response to the KAP domains has no direct relationship. The survey results suggest that most of the Saudi population has sound knowledge and a positive attitude and perception. Since the COVID-19 vaccines have been approved for use in pregnancy and above 12-year-old children by health authorities, the lack of information shown by a significant percentage of participants requires strategies to update this information. Awareness programs targeting all sections of the population must be continued to provide all the updates, including vaccinations for pregnant women and children.