Phytoassisted synthesis and characterization of palladium nanoparticles (PdNPs); with enhanced antibacterial, antioxidant and hemolytic activities

Synthesis of novel antibacterial and biocompatible polymer nanocomposite based on polysaccharide gum hydrogels

According to recent studies on the benefits of natural polymer-based hydrogels in biomedical applications, gellan gum (GG)/acacia gum (AG) hydrogel was prepared in this study. In order to regulate the mechanical behavior of the hydrogel, graphite carbon nitride (g-C3N4) was included in the hydrogel matrix. In addition, metal oxide nanoparticles ZnCuFe2O4 were added to the composite for antibacterial activity. The prepared GG-AG hydrogel/g-C3N4/ZnCuFe2O4 nanobiocomposite was characterized by using FE-SEM, FTIR, EDX, XRD and TGA. The nanobiocomposite exhibited spherical morphology, which was related to the incorporation of the metal oxide nanoparticles. GG-AG hydrogel/g-C3N4/ZnCuFe2O4 nanobiocomposite showed 95.11%, 92.73% and 88.97% biocompatibility toward HEK293T cell lines within 24 h, 48 h and 72 h incubation, respectively, which indicates that this nanobiocomposite is completely biocompatible with healthy cells. Also, the nanobiocomposite was able to inhibit Pseudomonas aeruginosa biofilm growth on its surface up to 87%. Rheological studies showed that the nanobiocomposite has a viscoelastic structure and has a water uptake ratio of 93.2%. In comparison with other similar studies, this nanobiocomposite has exhibited superior antibacterial activity complete biocompatibility and proper mechanical properties, high swelling and water absorption capability. These results indicate that GG-AG hydrogel/g-C3N4/ZnCuFe2O4 nanocomposite can be considered as a potential candidate for biomedical applications such as tissue engineering and wound healing.

A Systemic Review on the Synthesis, Characterization, and Applications of Palladium Nanoparticles in Biomedicine

Palladium nanoparticles (Pd NPs) have been considered as a potential candidate in the field of biomedical applications due to its unique properties such as huge catalytic, hydrogen storage, and sensing behavior. Therefore, Pd NPs have shown to have a significant potential for the development of antimicrobials, wound healing, antioxidant, and anticancer property in recent days. There are plenty of reports that showed superior properties of noble metals. However, only very few studies have been undertaken to explore the advantage of Pd NPs in the field of biomedical applications. This review reports detailed and comprehensive studies comprising of the synthesis, characterization, and potential applications of Pd NPs in biomedicine. This report provides evidences in the literature documented by early researchers to understand the potential applications of Pd NPs to be explored in various fields.

The construction of novel CuO/SnO2@g-C3N4 photocatalyst for efficient degradation of ciprofloxacin, methylene blue and photoinhibition of bacteria through efficient production of reactive oxygen species

Water pollution due to organic waste and various microorganisms cause severe health problems. Numbers of techniques are used to eliminate organic waste and microorganisms from water because water pollution is a substantial issue in the current era. In the present study, sustainable and effective CuO/SnO₂@g-C₃N₄ nanocomposites were prepared via green and chemical approach. The photo degradation of ciprofloxacin (CIP) and methylene blue (MB) by the green synthesized nanocomposite were tested. Visible and dark conditions both were used to conduct this test. The results showed that the nanocomposite is much more effective in light than in dark conditions. The synthesized nanocomposite was also tested both in light and dark against highly drug resistant microorganisms' Bacillus subtilis (B.subtilis) and Escherichia coli (E.coli). As a result, the antibacterial evaluation revealed substantial antibacterial activity in the presence of light, with a zone of inhibition covering an area of 19 (±0.5) mm and 20 (±0.1) mm, respectively, against gram negative and gram positive bacteria such as E. coli and B. subtilis. The results showed that the CuO/SnO₂@g-C₃N₄ nanocomposite is a stable, eco-friendly photocatalyst with significant resistance to CIP and MB degradation and a substantial inhibitory effect towards microorganisms in visible light.

Synthesis and characterization of activated carbon supported bimetallic Pd based nanoparticles and their sensor and antibacterial investigation

Activated carbon (AC) supported palladium cobalt bimetallic nanoparticles (PdCo@AC NPs) were obtained by green synthesis method using Cinnamomum verum (C. Verum) extract. The obtained NPs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Crystallography (XRD), Transmission Electron Microscope (TEM) and Ultraviolet Visible (UV-VIS) spectroscopy, and the functional groups and morphology of the nanoparticle were elucidated. The resulting particle size was found to be 2.467 nm. NPs were evaluated using Cyclic Voltammetry (CV), Scan Rate (SR), and Differential Pulse Voltammetry (DPV) techniques for potential dopamine sensors application. According to the obtained DPV results, Limit of Detection (LOD) and Limit of Quantitation (LOQ) values are found to be 5.68 pM and 17.21 pM, respectively. It was also observed that AC supported PdCo nanoparticles obtained from C. verum extract sensed dopamine quite well. Besides, to examine the antibacterial properties of NPs, antibacterial analyzes were performed with Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus). It was observed that it showed good antibacterial properties against gram positive (S. aureus) and gram negative (E. coli) bacteria. The study gave important results in terms of the synthesis of bimetallic NPs using the green synthesis method and their usability in different areas. With this study, it was observed that a good antibacterial dopamine sensor were obtained with the successful biogenic synthesis of AC supported PdCo bimetallic NPs.

Synthesis methods and applications of palladium nanoparticles: A review

Palladium (Pd) is a key component of many catalysts. Nanoparticles (NPs) offer a larger surface area than bulk materials, and with Pd cost increasing 5-fold in the last 10 years, Pd NPs are in increasing demand. Due to novel or enhanced physicochemical properties that Pd NPs exhibit at the nanoscale, Pd NPs have a wide range of applications not only in chemical catalysis, but also for example in hydrogen sensing and storage, and in medicine in photothermal, antibacterial, and anticancer therapies. Pd NPs, on the industrial scale, are currently synthesized using various chemical and physical methods. The physical methods require energy-intensive processes that include maintaining high temperatures and/or pressure. The chemical methods usually involve harmful solvents, hazardous reducing or stabilizing agents, or produce toxic pollutants and by-products. Lately, more environmentally friendly approaches for the synthesis of Pd NPs have emerged. These new approaches are based on the use of the reducing ability of phytochemicals and other biomolecules to chemically reduce Pd ions and form NPs. In this review, we describe the common physical and chemical methods used for the synthesis of Pd NPs and compare them to the plant- and bacteria-mediated biogenic synthesis methods. As size and shape determine many of the unique properties of Pd NPs on the nanoscale, special emphasis is given to the control of these parameters, clarifying how they impact current and future applications of this exciting nanomaterial.

New Green Approaches in Nanoparticles Synthesis: An Overview

Nanotechnology is constantly expanding, with nanomaterials being more and more used in common commercial products that define our modern life. Among all types of nanomaterials, nanoparticles (NPs) occupy an important place, considering the great amount that is produced nowadays and the diversity of their applications. Conventional techniques applied to synthesize NPs have some issues that impede them from being appreciated as safe for the environment and health. The alternative to these might be the use of living organisms or biological extracts that can be involved in the green approach synthesis of NPs, a process that is free of harmful chemicals, cost-effective and a low energy consumer. Several factors, including biological reducing agent concentration, initial precursor salt concentration, agitation, reaction time, pH, temperature and light, can influence the characteristics of biologically synthesized NPs. The interdependence between these reaction parameters was not explored, being the main impediment in the implementation of the biological method on an industrial scale. Our aim is to present a brief review that focuses on the current knowledge regarding how the aforementioned factors can control the size and shape of green-synthesized NPs. We also provide an overview of the biomolecules that were found to be suitable for NP synthesis. This work is meant to be a support for researchers who intend to develop new green approaches for the synthesis of NPs.

Eryngium caeruleum: an update on ethnobotany, phytochemistry and biomedical applications

BACKGROUND

A biennial or perennial plant of the Apiaceae family, Eryngium caeruleum M. Bieb. is traditionally used in medicine as an antitoxic, diuretic, digestive, anti-inflammatory and analgesic drug. This plant is widely distributed in temperate regions around the world. Young leaves of the plant are used in cooking as aromatic cooked vegetables in various local products in Iran.

PURPOSE

The current review aimed to highlight complete and updated information about the Eryngium caeruleum species, regarding botanical, ethnopharmacological, phytochemical data, pharmacological mechanisms as well as some nutritional properties. All this scientific evidence supports the use of this species in complementary medicine, thus opening new therapeutic perspectives for the treatment of some diseases.

METHODS

The information provided in this updated review is collected from several scientific databases such as PubMed/Medline, ScienceDirect, Mendeley, Scopus, Web of Science and Google Scholar. Ethnopharmacology books and various professional websites were also researched.

RESULTS

The phytochemical composition of the aerial parts and roots of E. caeruleum is represented by the components of essential oil (EO), phenolic compounds, saponins, protein, amino acids, fiber, carbohydrates, and mineral elements. The antioxidant, antimicrobial, antidiabetic, antihypoxic, and anti-inflammatory properties of E. caeruleum have been confirmed by pharmacological experiments with extracts using in vitro and in vivo methods. The syrup E. caeruleum relieved dysmenorrhea as effectively as Ibuprofen in the blinded, randomized, placebo-controlled clinical study.

CONCLUSION

Current evidence from experimental pharmacological studies has shown that the different bioactive compounds present in the species E. caeruleum have multiple beneficial effects on human health, being potentially active in the treatment of many diseases. Thus, the traditional uses of this species are supported based on evidence. In future, translational and human clinical studies are necessary to establish effective therapeutic doses in humans.

Synthesis, Crystal Structure, Theoretical Calculations, Antibacterial Activity, Electrochemical Behavior, and Molecular Docking of Ni(II) and Cu(II) Complexes with Pyridoxal-Semicarbazone

New Ni (II) and Cu (II) complexes with pyridoxal-semicarbazone were synthesized and their structures were solved by X-ray crystallography. This analysis showed the bis-ligand octahedral structure of [Ni(PLSC-H)₂]·H₂O and the dimer octahedral structure of [Cu(PLSC)(SO₄)(H₂O)]₂·2H₂O. Hirshfeld surface analysis was employed to determine the most important intermolecular interactions in the crystallographic structures. The structures of both complexes were further examined using density functional theory and natural bond orbital analysis. The photocatalytic decomposition of methylene blue in the presence of both compounds was investigated. Both compounds were active toward E. coli and S. aureus, with a minimum inhibition concentration similar to that of chloramphenicol. The obtained complexes led to the formation of free radical species, as was demonstrated in an experiment with dichlorofluorescein-diacetate. It is postulated that this is the mechanistic pathway of the antibacterial and photocatalytic activities. Cyclic voltammograms of the compounds showed the peaks of the reduction of metal ions. A molecular docking study showed that the Ni(II) complex exhibited promising activity towards Janus kinase (JAK), as a potential therapy for inflammatory diseases, cancers, and immunologic disorders.

Uncaria rhynchophylla mediated Ag/NiO nanocomposites: A new insight for the evaluation of cytotoxicity, antibacterial and photocatalytic applications

The increase of microbial resistance poses threat to the human health. Therefore, the efficient treatment of the microbial resistance is a global challenge and highly desired to explore it. During this study, the Ag/NiO nanocomposite was fabricated via simple and ecofriendly method, using Uncaria rhynchophylla extract as a reducing and capping agent to avoid the aggregation of as synthesized nanomaterials. Here, a range of characterization techniques were employed to characterize the sample which includes UV-vis spectroscopy, X-ray diffraction, FTIR spectroscopy, electron diffraction spectroscopy (EDX), scanning electron microscopy (SEM). Furthermore, the resultant nanocomposite demonstrated an efficient ability for the inhibition of both gram-positive and gram negative pathogenic multidrug resistant bacteria. Additionally, the Ag/NiO nanocomposite showed a durable antioxidant effect against DPPH that could still reach 63% at very low concentration, i.e. 0.5 mg/mL. Interestingly, the synthesized nanocomposite is efficient for the production of reactive oxygen species (ROS) and shows no hemolytic activity. Likewise, the Ag/NiO nanocomposite displayed excellent photocatalytic activity to degrade 85% methylene blue (MB) by 4 mg/25 mL and could be used for waste water treatment. It is believed that synthesized nanostructure with desirable morphology and preparation simplicity can be promising material for the antimicrobial, antioxidant and catalytic applications.

Facile synthesis of silver modified zinc oxide nanocomposite: An efficient visible light active nanomaterial for bacterial inhibition and dye degradation

The present study reports the synthesis of silver (Ag) decorated zinc oxide (ZnO) nanocomposite via green synthesis method by using Acacia arabica plant leaves extract as both reducing and capping agent. The results clearly indicate a uniform distribution of Ag nanoparticles (NPs) over ZnO surface. Various analytical and spectroscopic techniques were used for investigating the formation and morphology of as-synthesized Ag/ZnO nanocomposites. Emergence of SPR at 424 and 378 nm confirmed the synthesis of AgNPs and ZnO respectively. The confirmation of elemental composition and crystal structure of prepared nanomaterials (NMs) was carried out via EDX and XRD analysis. Results obtained from HRTEM and SEM analysis indicated small sized spherically shaped NMs. The as-synthesized was checked for its photocatalytic activity towards degradation of MB in the presence as well as absence of light irradiation. Results of degradation study revealed that Ag/ZnO exhibits remarkable photocatalytic activity in the presence of light whereby removing 90% of MB within 80 min. Moreover, the antibacterial activity of synthesized nanocomposite was examined in both visible light and dark conditions. The experiment showed that nanomaterial depicts enhanced antibacterial activity in light in comparison to dark. The results showed that the inhibition diameter of Ag/ZnO nanocomposite in light was found to be 18 (±0.2), 22 (±0.3) against E. coli and S. aureus respectively. The inhibition zone of the said nanomaterial against E. coli and S. aureus in dark was 11 (±0.3), 14 (±0.5) respectively. These results conclude that activity is delivered both in the presence of visible light and dark but efficiency of antibacterial activity is found to be more in visible light in comparison.