Green synthesis of biocompatible core-shell (Au-Ag) and hybrid (Au-ZnO and Ag-ZnO) bimetallic nanoparticles and evaluation of their potential antibacterial, antidiabetic, antiglycation and anticancer activities

A mechanistic overview on green assisted formulation of nanocomposites and their multifunctional role in biomedical applications

The importance of nanocomposites constantly attains attention because of their unique properties all across the fields especially in medical perspectives. The study of green-synthesized nanocomposites has grown to be extremely fascinating in the field of research. Nanocomposites are more promising than mono-metallic nanoparticles because they exhibit synergistic effects. This review encapsulates the current development in the formulation of plant-mediated nanocomposites by using several plant species and the impact of secondary metabolites on their biocompatible functioning. Phyto-synthesis produces diverse nanomaterials with biocompatibility, environment-friendliness, and in vivo actions, characterized by varying sizes, shapes, and biochemical nature. This process is advantageous to conventional physical and chemical procedures. New studies have been conducted to determine the biomedical efficacy of nanocomposites against various diseases. Unfortunately, there has been inadequate investigation into green-assisted nanocomposites. Incorporating phytosynthesized nanocomposites in therapeutic interventions not only enhances healing processes but also augments the host's immune defenses against infections. This review highlights the phytosynthesis of nanocomposites and their various biomedical applications, including antibacterial, antidiabetic, antiviral, antioxidant, antifungal, anti-cancer, and other applications, as well as their toxicity. This review also explores the mechanistic action of nanocomposites to achieve their designated tasks. Biogenic nanocomposites for multimodal imaging have the potential to exchange the conventional methods and materials in biomedical research. Well-designed nanocomposites have the potential to be utilized in various biomedical fields as innovative theranostic agents with the subsequent objective of efficiently diagnosing and treating a variety of human disorders.

Characterization of Green Synthesized Nanoparticles with Anti-diabetic Properties. A Systematic Review

BACKGROUND

Plants are used in medicine because they are low-cost, widely available, and have few side effects (compared to pharmacological treatment). Plants have phytocompounds with antidiabetic properties that can be delivered using nanoparticles (NPs).

OBJECTIVE

To describe the antidiabetic properties of green synthesized NPs (GSNPs) and their characterization methods.

METHODS

Three databases were consulted using the terms "type 2 diabetes mellitus," "antidiabetic effects," "phytochemicals," "plants," and "nanoparticles." Studies describing the antidiabetic effects (in vitro or animal models) of NPs synthesized by plant extracts and characterizing them through UV-Vis spectroscopy, FTIR, XRD, SEM, TEM, and DLS were included.

RESULTS

16 studies were included. In vitro studies reported enzyme inhibition values between 11% (H. polyrhizus) and 100% (A. concinna) for alfa-amylase and between 41.1% (M. zapota) and 100% (A. concinna) for alfa-glucosidase. Animal studies with Wistar Albino rats having diabetes (induced by alloxan or streptozotocin) reported improved blood glucose, triglycerides, total cholesterol, LDL, and HDL after treatment with GSNPs. Regarding characterization, NP sizes were measured with DLS (25-181.5 nm), SEM (52.1-91 nm), and TEM (8.7-40.6 nm). The surface charge was analyzed with zeta potential (-30.7 to -2.9 mV). UV-Vis spectroscopy was employed to confirm the formations of AgNPs (360-460 nm), AuNPs (524-540 nm), and ZnONPs (300-400 nm), and FTIR was used to identify plant extract functional groups.

CONCLUSION

GSNP characterization (shape, size, zeta potential, and others) is essential to know the viability and stability, which are important to achieve health benefits for biomedical applications. Studies reported good enzyme inhibition percentages in in vitro studies, decreasing blood glucose levels and improving lipid profiles in animal models with diabetes. However, these studies had limitations in the methodology and potential risk of bias, so results need careful interpretation.

Metallic nanoentities: Bio-engineered silver, gold, and silver/gold bimetallic nanoparticles for biomedical applications

This present study reports the biogenic synthesis of silver nanoparticles (AgNPs), gold nanoparticles (AuNPs) and Ag/Au bimetallic nanoparticles (BNPs) using bark extract of plant Tamarix aphylla (T.A). The bark extract contained total polyphenolic compounds and total flavonoids as 0.0362 mg/mg and 0.2928 mg/mg of the dried bark extract respectively. Silver nitrate (AgNO3) and hydrogen tetra chloroaurate trihydrate (HAuCl4.3H2O) were used as precursors while deionised water and methanol (CH3OH) were used as solvents. Synthesized nanoparticles were characterized through UV-visible spectroscopy, SEM (scanning electron microscopy), TEM (transmission electron microscopy) and FTIR (Fourier transform infrared) for their morphology, structure, and identification of different functional groups. The UV-visible spectra of AgNPs, AuNPs and Ag/Au BNPs showed peaks at 436, 532 and 527 nm respectively due to the excitation of Surface Plasmon Resonance. SEM and TEM images showed spherical and well distributed nanoparticles (NPs) with particle size as 29 nm (AgNPs), 13 nm (AuNPs) and 26 nm (Ag/Au BNPs). The synthesized NPs are significantly active against inhibition of free radicals, α-amylase, α-glucosidase and have anti inflammatory potential with AgNPs having the highest percent activity at 400 μg/ml, followed by Ag/Au BNPs. The same trend (AgNPs > Ag/AuBNPs > AuNPs) has been observed at all concentrations i.e. 100 μg/ml, 200 μg/ml and 400 μg/ml. AuNPs have shown lowest activity at all concentrations. So the current study strongly confirms use of T.A bark extract as reducing agent for synthesis of metal NPs and opens up a new possibility of using these green synthesized NPs as biomedicines. We also suggest further in vivo investigation to report any side effects if present.

Anticancer, antimicrobial and antioxidant activity of CuO-ZnO bimetallic nanoparticles: green synthesised from Eryngium foetidum leaf extract

In the present study, green synthetic pathway was adapted to synthesize CuO-ZnO bimetallic nanoparticles (BNPs) using Eryngium foetidum leaf extract and their anti-cancer activity against MCF7 breast cancer cell lines, anti-microbial activity and in vitro anti-oxidant activity were evaluated. Various bio-active compounds present in leaf extract were responsible for the reduction of CuO-ZnO NPs from respective Cu2+ and Zn2+ metal precursors. In the present study, the involvement of bio-active compounds present in E. foetidum extract before and after green synthesis of BNPs were evaluated for the first time. Rod-shaped and spherical structural morphology of synthesized BNPs were revealed by using FESEM, TEM, and XRD analysis with particle size ranged from 7 to 23 nm with an average size of 16.49 nm. The distribution of Cu and Zn were confirmed by elemental mapping. The green synthesized CuO-ZnO NPs showed significant cytotoxic effect with the inhibition rate 89.20 ± 0.03% at concentration of 500 μg/mL. Again, good antioxidant activity with IC50; 0.253 mg/mL and antimicrobial activity of BNPs were also evaluated with the increasing order of MIC; E. coli (7.81 μg/mL) < B. subtilis (62.5 μg/mL) < S. aureus (31.25 μg/mL).

Advances of nanoparticle derived from food in the control of α-dicarbonyl compounds-A review

α-Dicarbonyl compounds (α-DCs) are predominantly generated through the thermal processing of carbohydrate and protein-rich food. They are pivotal precursors to hazard formation, such as advanced glycation end products (AGEs), acrylamide, and furan. Their accumulation within the body will be genotoxicity and neurotoxicity. Recently, significant advancements have been made in nanotechnology, leading to the widespread utilization of nanomaterials as functional components in addressing the detrimental impact of α-DCs. This review focuses on the control of α-DCs through the utilization of nanoparticle-based functional factors, which were prepared by using edible components as resources. Four emerging nanoparticles are introduced including phenolic compounds-derived nanoparticle, plant-derived nanoparticle, active peptides-derived nanoparticle, and functional minerals-derived nanoparticle. The general control mechanisms as well as the recent evidence pertaining to the aforementioned aspects were also discussed, hoping to valuable helpful references for the development of innovative α-DCs scavengers and identifying the further scope of research.

Advances in preparation and application of antibacterial hydrogels

Bacterial infections, especially those caused by drug-resistant bacteria, have seriously threatened human life and health. There is urgent to develop new antibacterial agents to reduce the problem of antibiotics. Biomedical materials with good antimicrobial properties have been widely used in antibacterial applications. Among them, hydrogels have become the focus of research in the field of biomedical materials due to their unique three-dimensional network structure, high hydrophilicity, and good biocompatibility. In this review, the latest research progresses about hydrogels in recent years were summarized, mainly including the preparation methods of hydrogels and their antibacterial applications. According to their different antibacterial mechanisms, several representative antibacterial hydrogels were introduced, such as antibiotics loaded hydrogels, antibiotic-free hydrogels including metal-based hydrogels, antibacterial peptide and antibacterial polymers, stimuli-responsive smart hydrogels, and light-mediated hydrogels. In addition, we also discussed the applications and challenges of antibacterial hydrogels in biomedicine, which are expected to provide new directions and ideas for the application of hydrogels in clinical antibacterial therapy.

Burdock-Derived Composites Based on Biogenic Gold, Silver Chloride and Zinc Oxide Particles as Green Multifunctional Platforms for Biomedical Applications and Environmental Protection

Green nanotechnology is a rapidly growing field linked to using the principles of green chemistry to design novel nanomaterials with great potential in environmental and health protection. In this work, metal and semiconducting particles (AuNPs, AgClNPs, ZnO, AuZnO, AgClZnO, and AuAgClZnO) were phytosynthesized through a "green" bottom-up approach, using burdock (Arctium lappa L.) aqueous extract. The morphological (SEM/TEM), structural (XRD, SAED), compositional (EDS), optical (UV-Vis absorption and FTIR spectroscopy), photocatalytic, and bio-properties of the prepared composites were analyzed. The particle size was determined by SEM/TEM and by DLS measurements. The phytoparticles presented high and moderate physical stability, evaluated by zeta potential measurements. The investigation of photocatalytic activity of these composites, using Rhodamine B solutions' degradation under solar light irradiation in the presence of prepared powders, showed different degradation efficiencies. Bioevaluation of the obtained composites revealed the antioxidant and antibacterial properties. The tricomponent system AuAgClZnO showed the best antioxidant activity for capturing ROS and ABTS•+ radicals, and the best biocidal action against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The "green" developed composites can be considered potential adjuvants in biomedical (antioxidant or biocidal agents) or environmental (as antimicrobial agents and catalysts for degradation of water pollutants) applications.