Investigation of the Biological Applications of Biosynthesized Nickel Oxide Nanoparticles Mediated by Buxus wallichiana Extract

Molecular Docking Approach for Biological Interaction of Green Synthesized Nanoparticles

In recent years, significant progress has been made in the subject of nanotechnology, with a range of methods developed to synthesize precise-sized and shaped nanoparticles according to particular requirements. Often, the nanoparticles are created by employing dangerous reducing chemicals to reduce metal ions into uncharged nanoparticles. Green synthesis or biological approaches have been used recently to circumvent this issue because biological techniques are simple, inexpensive, safe, clean, and extremely productive. Nowadays, much research is being conducted on how different kinds of nanoparticles connect to proteins and nucleic acids using molecular docking models. Therefore, this review discusses the most recent advancements in molecular docking capacity to predict the interactions between various nanoparticles (NPs), such as ZnO, CuO, Ag, Au, and Fe3O4, and biological macromolecules.

Phytosynthesis of Nickel Oxide Nanoparticles and Their Antioxidant and Antibacterial Efficacy Studies

INTRODUCTION

 Multidrug-resistant (MDR) bacteria are widely acknowledged as a significant and pressing public health concern. Tribulus terrestris has been used as a health tonic in traditional medicine since ancient Vedic times. It was also utilized to synthesize small, well-dispersed metal nanoparticles (NPs). The biosynthesized nickel oxide nanoparticles (NiO-NPs) have a broad spectrum of biomedical uses.

OBJECTIVE

 The objective of the research was to utilize a green synthesis method to synthesize NiO-NPs using Tribulus terrestris, subsequently characterize, and this study aimed to assess the antioxidant and antibacterial effectiveness of these NPs against wound isolates that are resistant to multiple drugs.

MATERIALS AND METHODS

 The synthesis of NiO-NPs was achieved through the titration method, which is a green synthesis approach, and it was characterized by using techniques such as ultraviolet-visible spectroscopy (UV), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and energy dispersive X-ray (EDX). The antioxidant activity of the NPs was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and antibacterial activity was done using the agar well diffusion method. IBM SPSS Statistics for Windows, Version 21 (Released 2012; IBM Corp., Armonk, New York, United States) is used for statistical analysis.

RESULTS

 The biosynthesized NiO-NPs exhibited a color change from dark brown to dark green, indicating the successful reduction of the NPs. UV analysis peaks were observed at 310-350 nm, while FT-IR analysis showed the peaks at various wavelengths such as 629.31cm-1 (halo compound; C-Br stretching), 957.80cm-1(aromatic phosphates; P-O-C stretch), 1004.65cm-1 (aliphatic phosphates; P-O-C stretch), 1094.93cm-1 (organic siloxane or silicone; Si-O-Si), 1328.38cm-1 (dialkyl/aryl sulfones), 1604.88cm-1 (open-chain azo-N=N-), 2928.68cm-1 (methylene C-H asym/sym stretch), 3268.65cm-1 (normal polymeric "OH" stretch). The crystallinity of the NPs was determined to be 24.7%, while the remaining 75.6% exhibited an amorphous structure. The SEM image revealed a spherically agglomerated structure of the nano-ranged size NiO-NPs. The EDX analysis indicated the presence of elemental compositions Ni (7.4%), O (39.4%), and C (53.3%) in the biosynthesized NiO-NPs. These NPs demonstrated significant antibacterial activity against Pseudomonas aeruginosa and Klebsiella pneumoniae, moderate antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), and the lowest antibacterial activity against Enterococcus faecalis.

CONCLUSION

 Our in vitro results demonstrate that the biosynthesized NiO-NPs exhibit significant antioxidant and antibacterial activity. These NPs can be used as a future antimicrobial medication, particularly against MDR clinical wound isolates of K. pneumoniae, P. aeruginosa, and MRSA.

Synergistic antibacterial effects of exopolysaccharides/nickel-nanoparticles composites against multidrug-resistant bacteria

The need for an alternative treatment to fight infectious diseases caused by antibiotic-resistant bacteria is increasing. A possible way to overcome bacterial resistance to antibiotics is by reintroducing commonly used antibiotics with a sensitizer capable of enhancing their antimicrobial effect in resistant bacteria. Here, we use a composite composed of exopolysaccharide capped-NiO NPs, with antimicrobial effects against antibiotic-resistant Gram-positive and Gram-negative bacteria. It potentiated the antimicrobial effects of four different antibiotics (ampicillin, kanamycin, chloramphenicol, and ciprofloxacin) at lower concentrations than their minimal inhibitory concentrations. We observed that the Ni-composite synergistically enhanced, fourfold, the antibacterial effect of kanamycin and chloramphenicol against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa, as well as ampicillin against multidrug-resistant Staphylococcus aureus, and ciprofloxacin against multidrug-resistant Pseudomonas aeruginosa by eightfold. We also found that Ni-composite could not inhibit biofilm synthesis on the tested bacterial strains. Our results demonstrated the possibility of using metal nanoparticles, like NiO, as a sensitizer to overcome bacterial antibiotic resistance.

Biogenic Synthesis of Ag Nanoparticles of 18.27 nm by Zanthozylum armatum and Determination of Biological Potentials

Nanotechnology has become a dire need of the current era and the green synthesis of nanoparticles offers several advantages over other methods. Nanobiotechnology is an emerging field that contributes to many domains of human life, such as the formulation of nanoscale drug systems or nanomedicine for the diagnosis and treatment of diseases. Medicinal plants are the main sources of lead compounds, drug candidates and drugs. This work reports the green synthesis of Ag nanoparticles (AgNPs) using the aqueous bark extract of Zanthozylum armatum, which was confirmed by a UV absorption at 457 nm. XRD analysis revealed an average size of 18.27 nm and SEM showed the particles’ spherical shape, with few irregularly shaped particles due to the aggregation of the AgNPs. FT-IR revealed the critical functional groups of phytochemicals which acted as reducing and stabilizing agents. The bark extract showed rich flavonoids (333 mg RE/g) and phenolic contents (82 mg GAE/g), which were plausibly responsible for its high antioxidant potency (IC₅₀ = 14.61 µg/mL). Extract-loaded AgNPs exhibited the highest but equal inhibition against E. coli and P. aeruginosa (Z.I. 11.0 mm), whereas methanolic bark extract inhibited to a lesser extent, but equally to both pathogens (Z.I. 6.0 mm). The aqueous bark extract inhibited P. aeruginosa (Z.I. 9.0 mm) and (Z.I. 6.0 mm) E. coli. These findings—especially the biosynthesis of spherical AgNPs of 18.27 nm—provide promise for further investigation and for the development of commercializable biomedical products.