Green synthesis of multifunctional silver and gold nanoparticles from the oriental herbal adaptogen: Siberian ginseng

Collision of herbal medicine and nanotechnology: a bibliometric analysis of herbal nanoparticles from 2004 to 2023

BACKGROUND

Herbal nanoparticles are made from natural herbs/medicinal plants, their extracts, or a combination with other nanoparticle carriers. Compared to traditional herbs, herbal nanoparticles lead to improved bioavailability, enhanced stability, and reduced toxicity. Previous research indicates that herbal medicine nanomaterials are rapidly advancing and making significant progress; however, bibliometric analysis and knowledge mapping for herbal nanoparticles are currently lacking. We performed a bibliometric analysis by retrieving publications related to herbal nanoparticles from the Web of Science Core Collection (WoSCC) database spanning from 2004 to 2023. Data processing was performed using the R package Bibliometrix, VOSviewers, and CiteSpace.

RESULTS

In total, 1876 articles related to herbal nanoparticles were identified, originating from various countries, with China being the primary contributing country. The number of publications in this field increases annually. Beijing University of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, and Saveetha University in India are prominent research institutions in this domain. The Journal "International Journal of Nanomedicine" has the highest number of publications. The number of authors of these publications reached 8234, with Yan Zhao, Yue Zhang, and Huihua Qu being the most prolific authors and Yan Zhao being the most frequently cited author. "Traditional Chinese medicine," "drug delivery," and "green synthesis" are the main research focal points. Themes such as "green synthesis," "curcumin," "wound healing," "drug delivery," and "carbon dots" may represent emerging research areas.

CONCLUSIONS

Our study findings assist in identifying the latest research frontiers and hot topics, providing valuable references for scholars investigating the role of nanotechnology in herbal medicine.

Frontiers of stem cell engineering for nanotechnology-mediated drug delivery systems

Background and purpose

Cell biology approaches have gained a successful integration, development and application of nanotechnology with stem cell engineering and have led to the emergence of a new interdisciplinary field known as stem cell nanotechnology (SCN). Recent studies showed the potential and the advancement of developments for SCN applications in drug delivery systems. Cancer, neurodegenerative, muscle and blood diseases, cell and gene therapies, and tissue engineering and regenerative medicine applications are the important targets of SCN.

Experimental approach

In this overview, we searched the literature using the common online websites for research and read the open access, full-text available articles since 2013.

Key results

The studies vary according to the type of disease they targeted and the strategies they proposed, whether diagnostic or therapeutic. In addition to the use of stem cells, the utilisation of their membranes, secretomes, exosomes and extracellular vesicles with an appropriate nanotechnology strategy is also an aspect of the research.

Conclusion

This brief overview of stem cell nanotechnology over the last ten years aims to provide insight into the frontiers of stem cell engineering for nanotechnology-mediated drug delivery systems.

Advancing sustainable agriculture: a critical review of smart and eco-friendly nanomaterial applications

Undoubtedly, nanoparticles are one of the ideal choices for achieving challenges related to bio sensing, drug delivery, and biotechnological tools. After gaining success in biomedical research, scientists are exploring various types of nanoparticles for achieving sustainable agriculture. The active nanoparticles can be used as a direct source of micronutrients or as a delivery platform for delivering the bioactive agrochemicals to improve crop growth, crop yield, and crop quality. Till date, several reports have been published showing applications of nanotechnology in agriculture. For instance, several methods have been employed for application of nanoparticles; especially metal nanoparticles to improve agriculture. The physicochemical properties of nanoparticles such as core metal used to synthesize the nanoparticles, their size, shape, surface chemistry, and surface coatings affect crops, soil health, and crop-associated ecosystem. Therefore, selecting nanoparticles with appropriate physicochemical properties and applying them to agriculture via suitable method stands as smart option to achieve sustainable agriculture and improved plant performance. In presented review, we have compared various methods of nanoparticle application in plants and critically interpreted the significant differences to find out relatively safe and specific method for sustainable agricultural practice. Further, we have critically analyzed and discussed the different physicochemical properties of nanoparticles that have direct influence on plants in terms of nano safety and nanotoxicity. From literature review, we would like to point out that the implementation of smaller sized metal nanoparticles in low concentration via seed priming and foliar spray methods could be safer method for minimizing nanotoxicity, and for exhibiting better plant performance during stress and non-stressed conditions. Moreover, using nanomaterials for delivery of bioactive agrochemicals could pose as a smart alternative for conventional chemical fertilizers for achieving the safer and cleaner technology in sustainable agriculture. While reviewing all the available literature, we came across some serious drawbacks such as the lack of proper regulatory bodies to control the usage of nanomaterials and poor knowledge of the long-term impact on the ecosystem which need to be addressed in near future for comprehensive knowledge of applicability of green nanotechnology in agriculture.

A comprehensive and systemic review of ginseng-based nanomaterials: Synthesis, targeted delivery, and biomedical applications

Among 17 Panax species identified across the world, Panax ginseng (Korean ginseng), Panax quinquefolius (American ginseng), and Panax notoginseng (Chinese ginseng) are highly recognized for the presence of bioactive compound, ginsenosides and their pharmacological effects. P. ginseng is widely used for synthesis of different types of nanoparticles compared to P. quinquefolius and P. notoginseng. The use of nano-ginseng could increase the oral bioavailability, membrane permeability, and thus provide effective delivery of ginsenosides to the target sites through transport system. In this review, we explore the synthesis of ginseng nanoparticles using plant extracts from various organs, microbes, and polymers, as well as their biomedical applications. Furthermore, we highlight transporters involved in transport of ginsenoside nanoparticles to the target sites. Size, zeta potential, temperature, and pH are also discussed as the critical parameters affecting the quality of ginseng nanoparticles synthesis.

Biosynthesis of Functional Silver Nanoparticles Using Callus and Hairy Root Cultures of Aristolochia manshuriensis

This study delves into the novel utilization of Aristolochia manshuriensis cultured cells for extracellular silver nanoparticles (AgNPs) synthesis without the need for additional substances. The presence of elemental silver has been verified using energy-dispersive X-ray spectroscopy, while distinct surface plasmon resonance peaks were revealed by UV-Vis spectra. Transmission and scanning electron microscopy indicated that the AgNPs, ranging in size from 10 to 40 nm, exhibited a spherical morphology. Fourier-transform infrared analysis validated the abilty of A. manshuriensis extract components to serve as both reducing and capping agents for metal ions. In the context of cytotoxicity on embryonic fibroblast (NIH 3T3) and mouse neuroblastoma (N2A) cells, AgNPs demonstrated varying effects. Specifically, nanoparticles derived from callus cultures exhibited an IC50 of 2.8 µg/mL, effectively inhibiting N2A growth, whereas AgNPs sourced from hairy roots only achieved this only at concentrations of 50 µg/mL and above. Notably, all studied AgNPs' treatment-induced cytotoxicity in fibroblast cells, yielding IC50 values ranging from 7.2 to 36.3 µg/mL. Furthermore, the findings unveiled the efficacy of the synthesized AgNPs against pathogenic microorganisms impacting both plants and animals, including Agrobacterium rhizogenes, A. tumefaciens, Bacillus subtilis, and Escherichia coli. These findings underscore the effectiveness of biotechnological methodologies in offering advanced and enhanced green nanotechnology alternatives for generating nanoparticles with applications in combating cancer and infectious disorders.

Synthesis of Au-Ag bimetallic nanoparticles using Korean red ginseng (Panax ginseng Meyer) root extract for chemo-photothermal anticancer therapy

Green synthesis strategies have been widely applied for the preparation of versatile nanomaterials. Gold nanospheres with an average size of 6.95 ± 2.25 nm were green synthesized by using a 70% ethanol extract of Korean red ginseng (Panax ginseng Meyer) root as a reducing agent. A seed-mediated synthesis was conducted to prepare Au-Ag bimetallic nanoparticles using gold nanospheres as seeds. Remarkably, Au-Ag bimetallic nanoparticles with an average size of 80.4 ± 11.9 nm were synthesized. Scanning transmission electron microscopy, energy dispersive X-ray spectroscopy and elemental mappings revealed bimetallic nanoparticles with Au-Ag alloy core and Au-rich shells. A face-centered cubic structure of Au-Ag bimetallic nanoparticles was confirmed by X-ray diffraction analysis. For Au-Ag bimetallic nanoparticles, the ratio of Ag/Au was 0.20 which was detected and analyzed by inductively coupled plasma-mass spectrometry. Gold nanospheres and Au-Ag bimetallic nanoparticles were functionalized by PEGylation, folic acid conjugation and grafting onto graphene oxide. Finally, docetaxel was loaded for evaluating the in vitro cell viability on cancer cells. Successful functionalization was confirmed by Fourier-transform infrared spectra. The anticancer activity of the docetaxel-loaded nanoparticles was higher than that of their non-docetaxel-loaded counterparts. The highest anticancer activity on human gastric adenocarcinoma cells (AGS) was observed in the docetaxel-loaded gold nanospheres that were functionalized by PEGylation, folic acid conjugation and grafting onto graphene oxide. Additionally, grafting onto graphene oxide and docetaxel loading induced high intracellular reactive oxygen species generation. For chemo-photothermal (PTT) anticancer therapy, cell viability was investigated using near-infrared laser irradiation at 808 nm. The highest chemo-PTT anticancer activity on AGS cells was observed in the docetaxel-loaded Au-Ag bimetallic nanoparticles. Therefore, the newly prepared docetaxel-loaded Au-Ag bimetallic nanoparticles in the current report have potential applications in chemo-PTT anticancer therapy.

Anticancer potential of biologically synthesized silver nanoparticles using Lantana camara leaf extract

A Lantana camara leaf (LC) extract was used as a mild reducing agent to produce silver metal nanoparticles (LC-AgNPs) efficiently. The size, shape, and morphology of synthesized silver nanoparticles were verified. LC-AgNPs were found in LC extract by XRD. The optimal concentrations of silver nitrate and LC extract necessary for the production of stable silver nanoparticles were determined. The LC-AgNPs were found spherical in form and monodispersed. Under optimal conditions, the round LC-AgNPs of 50-90 nm were utilized to cure lung cancer (A549 cell line) and breast cancer (MCF7) cell lines. Finally, the produced LC-AgNPs enhanced anti-cancer efficacy against A549 cells, with an IC50 = 49.52 g/mL. Similarly, the effect of LC-AgNPs on MCF7 cell line was assessed using an MTT test and inhibitory concentration (IC50) was determined found that 46.67 g/mL.

Biosynthesis of Gold and Silver Nanoparticles Using Phytochemical Compounds

Gold and silver nanoparticles are nanoparticles that have been widely used in various fields and have shown good benefits. The method of nanoparticle biosynthesis utilizing plant extracts, also known as green synthesis, has become a promising method considering the advantages it has compared to other synthesis methods. This review aims to give an overview of the phytochemical compounds in plants used in the synthesis of gold and silver nanoparticles, the nanoparticle properties produced using plant extracts based on the concentration and structure of phytochemical compounds, and their applications. Phytochemical compounds play an important role as reducing agents and stabilizers in the stages of the synthesis of nanoparticles. Polyphenol compounds, reducing sugars, and proteins are the main phytochemical compounds that are responsible for the synthesis of gold and silver nanoparticles. The concentration of phytochemical compounds affects the physical properties, stability, and activity of nanoparticles. This is important to know to be able to overcome limitations in controlling the physical properties of the nanoparticles produced. Based on structure, the phytochemical compounds that have ortho-substituted hydroxyl result in a smaller size and well-defined shape, which can lead to greater activity and stability. Furthermore, the optimal condition of the biosynthesis process is required to gain a successful reaction that includes setting the metal ion concentration, temperature, reaction time, and pH.

Highin vitroactivity of gold and silver nanoparticles from Solanum mammosum L. against SARS-CoV-2 surrogate Phi6 and viral model PhiX174

The search for new strategies to curb the spread of the SARS-CoV-2 coronavirus, which causes COVID-19, has become a global priority. Various nanomaterials have been proposed as ideal candidates to inactivate the virus; however, because of the high level of biosecurity required for their use, alternative models should be determined. This study aimed to compare the effects of two types of nanomaterials gold (AuNPs) and silver nanoparticles (AgNPs), recognized for their antiviral activity and affinity with the coronavirus spike protein using PhiX174 and enveloped Phi6 bacteriophages as models. To reduce the toxicity of nanoparticles, a species known for its intermediate antiviral activity,Solanum mammosumL. (Sm), was used. NPs prepared with sodium borohydride (NaBH₄) functioned as the control. Antiviral activity against PhiX174 and Phi6 was analyzed using its seed, fruit, leaves, and essential oil; the leaves were the most effective on Phi6. Using the aqueous extract of the leaves, AuNPs-Sm of 5.34 ± 2.25 nm and AgNPs-Sm of 15.92 ± 8.03 nm, measured by transmission electron microscopy, were obtained. When comparing NPs with precursors, both gold(III) acetate and silver nitrate were more toxic than their respective NPs (99.99% at 1 mg ml^-1). The AuNPs-Sm were less toxic, reaching 99.30% viral inactivation at 1 mg ml^-1, unlike the AgNPs-Sm, which reached 99.94% at 0.01 mg ml^-1. In addition, cell toxicity was tested in human adenocarcinoma alveolar basal epithelial cells (A549) and human foreskin fibroblasts. Gallic acid was the main component identified in the leaf extract using high performance liquid chromatography with diode array detection (HPLC-DAD). The FT-IR spectra showed the presence of a large proportion of polyphenolic compounds, and the antioxidant analysis confirmed the antiradical activity. The control NPs showed less antiviral activity than the AuNPs-Sm and AgNPs-Sm, which was statistically significant; this demonstrates that both theS. mammosumextract and its corresponding NPs have a greater antiviral effect on the surrogate Phi bacteriophage, which is an appropriate model for studying SARS-CoV-2.

Ginsenoside compound K-loaded gold nanoparticles synthesized from Curtobacterium proimmune K3 exerts anti-gastric cancer effect via promoting PI3K/Akt-mediated apoptosis

Background

Compound K (CK) is the minor ginsenoside present in fermented Panax ginseng extract. Despite the pharmacological efficacy of CK, its industrial use has been restricted due to its low water solubility and poor permeability. To overcome this defect, our study was to synthesize gold nanoparticles from CK (CK-AuNPs) to investigate their potential as anticancer candidates.

Methods

To biologically synthesize CK-AuNPs, a novel strain, Curtobacterium proimmune K3, was isolated from fermented ginseng beverage, then combined with CK and gold salts to biosynthesize gold nanoparticles (CurtoCK-AuNPs). Their physicochemical characteristics were evaluated using UV–Vis spectrometry, FE-TEM, EDX, elemental mapping, XRD, SAED, DLS and TGA.

Results

CurtoCK-AuNPs exerted significant selective cytotoxic effects on AGS human gastric cancer cells. Fluorescence staining with Hoechst, propidium iodide, and MitoTracker demonstrated that CurtoCK-AuNPs induce apoptosis and mitochondrial damage, respectively. Quantitative real-time PCR and western blotting analyses showed that cytotoxic effect of CurtoCK-AuNPs were involved in apoptosis, based on their activation of Bax/Bcl-2, cytochrome c, caspase 9, and caspase 3, as well as their suppression of PI3K–Akt signaling.

Conclusion

Our findings provide data for understanding the molecular mechanisms of nanoparticles; thus, providing insight into the development of alternative medications based on gold nanoparticles of ginseng-derived CK.

Effect of Currently Available Nanoparticle Synthesis Routes on Their Biocompatibility with Fibroblast Cell Lines

Nanotechnology has acquired significance in dental applications, but its safety regarding human health is still questionable due to the chemicals utilized during various synthesis procedures. Titanium nanoparticles were produced by three novel routes, including Bacillus subtilis, Cassia fistula and hydrothermal heating, and then characterized for shape, phase state, size, surface roughness, elemental composition, texture and morphology by SEM, TEM, XRD, AFM, DRS, DLS and FTIR. These novel titanium nanoparticles were tested for cytotoxicity through the MTT assay. L929 mouse fibroblast cells were used to test the cytotoxicity of the prepared titanium nanoparticles. Cell suspension of 10% DMEM with 1 × 104 cells was seeded in a 96-well plate and incubated. Titanium nanoparticles were used in a 1 mg/mL concentration. Control (water) and titanium nanoparticles stock solutions were prepared with 28 microliters of MTT dye and poured into each well, incubated at 37 °C for 2 h. Readings were recorded on day 1, day 15, day 31, day 41 and day 51. The results concluded that titanium nanoparticles produced by Bacillus subtilis remained non-cytotoxic because cell viability was >90%. Titanium nanoparticles produced by Cassia fistula revealed mild cytotoxicity on day 1, day 15 and day 31 because cell viability was 60−90%, while moderate cytotoxicity was found at day 41 and day 51, as cell viability was 30−60%. Titanium nanoparticles produced by hydrothermal heating depicted mild cytotoxicity on day 1 and day 15; moderate cytotoxicity on day 31; and severe cytotoxicity on day 41 and day 51 because cell viability was less than 30% (p < 0.001). The current study concluded that novel titanium nanoparticles prepared by Bacillus subtilis were the safest, more sustainable and most biocompatible for future restorative nano-dentistry purposes.

Biologically synthesis of gold nanoparticles using Cirsium japonicum var. maackii extract and the study of anti-cancer properties on AGS gastric cancer cells

Plant extract-mediated synthesis of metal nanoparticles (NPs) is an eco-friendly and cost-effective biosynthesis method that is more suitable for biological applications than chemical ones. We prepared novel gold NPs (AuNPs), Cirsium japonicum mediated-AuNPs (CJ-AuNPs), using a biosynthetic process involving Cirsium japonicum (Herba Cirsii, CJ) ethanol extract. The physicochemical properties of CJ-AuNPs were characterized using spectrometric and microscopic analyses. The in vitro stability of CJ-AuNPs was studied for 3 months. Moreover, the selective human gastric adenocarcinoma (AGS) cell killing ability of CJ-AuNPs was verified in cancer and normal cells. An in vitro study revealed that CJ-AuNPs trigger oxidative stress and iron-dependent ferroptosis in AGS cells. Mechanistically, CJ-AuNPs induced mitochondrial reactive oxygen species (ROS), Fe²⁺, and lipid peroxidation accumulation, and mitochondrial damage by destroying the glutathione peroxidase-4 (GPX4)-dependent antioxidant capacity. Furthermore, in a xenograft mouse model implanted with AGS cells, treatment with 2.5, 5, and 10 mg/kg CJ-AuNPs for 16 days reduced tumor xenograft growth in a dose dependent manner in vivo without systemic toxicity. These results demonstrate that CJ-AuNPs exert anticancer effects in vitro and in vivo by inducing ferroptosis-mediated cancer cell death. This study, based on green-synthesized nanodrug-induced ferroptosis, provides new insight into potential developments in cancer therapies.

Structural characterization and anti-inflammatory properties of green synthesized chitosan/compound K‑gold nanoparticles

Ginsenoside compound K (CK) has been shown to exhibit anti-inflammatory properties. In this study, to encourage biomedical applications of biosynthesized gold nanoparticles (AuNPs) with anti-inflammatory effects, AuNPs loaded with ginsenoside compound K were prepared using a self-assembly technique with chitosan as the carrier. Optimal conditions for chitosan-ginsenoside CK‑gold nanoparticles (CS-CK-AuNPs) formation were monitored using UV-Vis absorption spectroscopy. The physicochemical characterization of CS-CK-AuNPs was performed using FE-TEM, FE-SEM, XRD, DLS, FTIR and NMR techniques. In the stability test, CS-CK-AuNPs did not show any significant changes up to 4 weeks. Fluorescence imaging demonstrated that CS-CK-AuNPs promoted cellular uptake in vitro, but did not exhibit significant cytotoxicity at concentrations below 40 μg/mL. Additionally, the CS-CK-AuNPs inhibited NO production, and reduced the expression and secretion of inflammatory cytokines (IL-1β, IL-6, and TNF-α) via inhibition of the nuclear factor-kappaB (NF-κB) pathway in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Thus, CS-CK-AuNPs are novel candidates for developing anti-inflammatory agent. This study also confirms the superiority of chitosan AuNPs as oral delivery vehicles for inflammation-related diseases.

Superior inhibition of virulence and biofilm formation of Pseudomonas aeruginosa PAO1 by phyto-synthesized silver nanoparticles through anti-quorum sensing activity

Quorum sensing (QS)-regulated bacterial biofilm formation is a crucial issue in causing resistance against existing antibiotics. There is a considerable necessity to disrupt the interrelationship between bacterial QS, virulence, and biofilm formation. Disabling QS could be a novel tactic of great clinical importance. Here, we biosynthesized silver nanoparticles (Ka-AgNPs) using the aqueous leaf extract of Koelreuteria paniculata as a reducing and capping agents. The UV-Vis spectroscopy confirmed the synthesis of Ka-AgNPs as a characterization peak observed at 420 nm. TEM image revealed the spherical shape distribution of Ka-AgNPs with average particle size of 30.0 ± 5 nm. The anti-QS activity of Ka-AgNPs was tested against a bio-indicator bacterium Chromobacterium violaceum 12472 and a multi-drug resistant model strain of Pseudomonas aeruginosa (PAO1). The results demonstrated that the Ka-AgNPs superiorly inhibited QS-regulated virulence factors in PAO1 without affecting cell viability compared to chemically synthesized AgNPs (Cs-AgNPs). The Ka-AgNPs effectively suppressed the formation of biofilm of PAO1. RT-PCR results revealed that the Ka-AgNPs inhibited the expression of QS-regulated virulence genes of PAO1. These results suggest that the phyto-synthesized AgNPs could be used as promising anti-infective agents for treating drug-resistant P. aeruginosa.

A flower-like ionic molecularly imprinted membrane for the deglycosylation of rutin

A kind of molecularly imprinted polymer based on ionic liquids (MIPIL) with flower-like shape was developed for the adsorption of rutin and its deglycosylated product. The MIPIL film was characterized by scanning electron microscope (SEM) and X-ray photo-electron spectroscopy (XPS). The adsorption capacity of quercetin on the proposed imprinted cavity of rutin in the presence of glucose and rhamnose was 3.7 ± 0.017 times as much as that in the absence of glucose and rhamnose. And the adsorption capacity of quercetin varied with the concentration of glucose and rhamnose changing. Thus, the proposed MIPIL film coupled with HPLC was used to explore the deglycosylation of rutin by tracking rutin and quercetin, which confirmed to the pseudo-first-order reaction kinetic with the constant of 0.044 ± 1.5 × 10^-4 min^-1 at 35 °C. The rutin and quercetin were quantified using the above MIPIL film in the two Ginkgo leaves extracted by pure water and pure ethanol, respectively. Because of lower solubility in water, the content of rutin in ethanol extraction solution was higher than in water solution. On the contrary, the content of quercetin in water extraction solution was higher than in ethanol solution, which resulted from the higher solubility of glucose and rhamnose in water. The RSD ranged from 2.8 to 4.5%, and the recovery rate ranged from 91.9 to 105.3%.

Nanoemulsions prepared from mountain ginseng-mediated gold nanoparticles and silydianin increase the anti-inflammatory effects by regulating NF-κB and MAPK signaling pathways

In order to increase the bioavailability of mountain ginseng (MG), gold nanoparticles (MG-AuNPs) were biologically synthesized from MG extract, and an oil-in-water (O/W) nanoemulsion (SMG-AuNEs) was prepared from MG-AuNPs and a phytochemical silydianin. The physical stability of SMG-AuNEs were monitored and optimized in terms of particle size, pH value, zeta potential, and polydispersity index. The chemicostructural properties of the prepared MG-AuNPs and SMG-AuNEs were characterized using various spectrometric and microscopic analyses, such as EDX spectroscopy, FT-IR spectroscopy, and TEM. The effect of both nanomaterial samples on the anti-inflammatory activity and their underlying mechanism was compared in LPS-stimulated RAW 264.7 cells. SMG-AuNEs did not show toxic effects against RAW 264.7 macrophages, HaCaT keratinocytes, and normal dermal fibroblasts. SMG-AuNEs exhibited significantly higher inhibition of pro-inflammatory genes and proteins, including IL-1β, IL-6, and TNF-α, compared with those of MG-AuNPs and silydianin. Western blotting analysis revealed that the MAPK and NF-κB signalings were highly inhibited by SMG-AuNEs treatment. Hence, this study shows that nano-emulsification of gold nanoparticles prepared from MG is a useful method for augmenting the anti-inflammatory potential of MG. This study may serve as a foundation for using MG as a functional ingredient in anti-inflammatory agents. Our results may implicate the use of nanoemulsions to develop new anti-inflammatory products using MG.

Binary Effects of Gynostemma Gold Nanoparticles on Obesity and Inflammation via Downregulation of PPARγ/CEPBα and TNF-α Gene Expression

Nanoscience is a multidisciplinary skill with elucidated nanoscale particles and their advantages in applications to various fields. Owing to their economical synthesis, biocompatible nature, and widespread biomedical and environmental applications, the green synthesis of metal nanoparticles using medicinal plants has become a potential research area in biomedical research and functional food formulations. Gynostemma pentaphyllum (GP) has been extensively used in traditional Chinese medicine to cure several diseases, including diabetes mellitus (DM). This is the first study in which we examined the efficacy of G. pentaphyllum gold nanoparticles (GP-AuNPs) against obesity and related inflammation. GP extract was used as a capping agent to reduce Au²⁺ to Au⁰ to form stable gold nanoparticles. The nanoparticles were characterized by using UV–VIS spectroscopy, and TEM images were used to analyze morphology. In contrast, the existence of the functional group was measured using FTIR, and size and shape were examined using XRD analysis. In vitro analysis on GP-AuNPs was nontoxic to RAW 264.7 cells and 3T3-L1 cells up to a specific concentration. It significantly decreased lipid accumulation in 3T3-L1 obese and reduced NO production in Raw 264.7 macrophage cells. The significant adipogenic genes PPARγ and CEPBα and a major pro-inflammatory cytokine TNF-α expression were quantified using RT-PCR. The GP-AuNPs decreased the face of these genes remarkably, revealing the antiadipogenic and anti-inflammatory activity of our synthesized GP-AuNPs. This study represents thorough research on the antiobesity effect of Gynostemma pentaphyllum gold nanoparticles synthesized using a green approach and the efficacy instead of related inflammatory responses.

Synthesis and Characterization of Titanium Oxide Nanoparticles with a Novel Biogenic Process for Dental Application

The prevalence of dental caries has been largely consonant over time despite the enhancement in dental technologies. This study aims to produce novel GIC restorative material by incorporating TiO₂ nanoparticles synthesized by Bacillus subtilis for the treatment of dental caries. The TiO₂ nanoparticles were prepared by inoculating a fresh culture of Bacillus subtilis into a nutrient broth for 24 h, which was then characterized by XRD, DRS, FTIR, AFM, SEM, TEM and EDX. These TiO₂ nanoparticles were incorporated in GIC restorative material at different concentrations (0–10% TiO₂ -GIC) and were tested for their mechanical properties in a universal testing machine. The XRD analysis revealed synthesis of anatase and rutile-phased TiO₂ nanoparticles with a particle size of 70.17 nm that was further confirmed by SEM and TEM analysis. The EDX spectrum indicated prominent peaks of titanium and oxygen with no impurities in the prepared material. Treatment with 5% TiO₂ -GIC proved to be most effective for the treatment of dental caries with no observable cytotoxic effect. An increase in the compressive strength of TiO₂ nanoparticle-reinforced GIC was observed as the concentration of the TiO₂ nanoparticles was increased up to 5%; subsequently, the compressive strength was lowered. An increase in the flexural strength was observed in GIC containing 0%, 3% and 5% TiO₂ nanoparticles sequentially. Based on the results, it can be concluded that Bacillus subtilis-derived TiO₂ nanoparticles have excellent potential for developing next generation of restorative materials for dental issues.

Strong Antimicrobial Activity of Silver Nanoparticles Obtained by the Green Synthesis in Viridibacillus sp. Extracts

Recently, green silver nanoparticles (G-AgNPs) have gained much attention in medical science due to their extraordinary effects against multidrug-resistant microorganisms. The strong antimicrobial nature of G-AgNPs corresponds to their unique physicochemical properties such as size, shape, surface charge, and active surface groups available to interact with the pathogens. The current study demonstrates a simple, environmentally friendly, and economical method to produce G-AgNPs from an environmental isolate of Viridibacillus sp. The produced G-AgNPs were characterized by various analytical methods, including UV-Vis spectroscopy, single-particle inductively coupled plasma-mass spectrometry (sp-ICP-MS), scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), elemental mapping, transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), and Thermogravimetric analysis (TGA). The reduction of Ag⁺ to Ag° was observed by UV-Vis spectroscopy, which demonstrated the formation of stable G-AgNPs with a Surface Plasmon Resonance (SPR) band at the maximum of 430 nm. TEM analysis demonstrated that the G-AgNPs were spherical with a 5–30 nm size range. The produced G-AgNPs were stable for more than 1 year in an aqueous solution at 4°C. Importantly, G-AgNPs showed remarkable antimicrobial activity against Gram-negative pathogens- E. coli and P. aeruginosa with MIC values of 0.1 and 4 μg/mL and MBC values of 1 and 8 μg/mL, respectively. This level of antimicrobial activity is superior to other AgNPs reported in the literature.

Green Synthesis and Potential Antibacterial Applications of Bioactive Silver Nanoparticles: A Review

Green synthesis of silver nanoparticles (AgNPs) using biological resources is the most facile, economical, rapid, and environmentally friendly method that mitigates the drawbacks of chemical and physical methods. Various biological resources such as plants and their different parts, bacteria, fungi, algae, etc. could be utilized for the green synthesis of bioactive AgNPs. In recent years, several green approaches for non-toxic, rapid, and facile synthesis of AgNPs using biological resources have been reported. Plant extract contains various biomolecules, including flavonoids, terpenoids, alkaloids, phenolic compounds, and vitamins that act as reducing and capping agents during the biosynthesis process. Similarly, microorganisms produce different primary and secondary metabolites that play a crucial role as reducing and capping agents during synthesis. Biosynthesized AgNPs have gained significant attention from the researchers because of their potential applications in different fields of biomedical science. The widest application of AgNPs is their bactericidal activity. Due to the emergence of multidrug-resistant microorganisms, researchers are exploring the therapeutic abilities of AgNPs as potential antibacterial agents. Already, various reports have suggested that biosynthesized AgNPs have exhibited significant antibacterial action against numerous human pathogens. Because of their small size and large surface area, AgNPs have the ability to easily penetrate bacterial cell walls, damage cell membranes, produce reactive oxygen species, and interfere with DNA replication as well as protein synthesis, and result in cell death. This paper provides an overview of the green, facile, and rapid synthesis of AgNPs using biological resources and antibacterial use of biosynthesized AgNPs, highlighting their antibacterial mechanisms.

The Immune-Enhancing Properties of Hwanglyeonhaedok-Tang-Mediated Biosynthesized Gold Nanoparticles in Macrophages and Splenocytes

Background

Despite great advances in the field of immunotherapy, there is still a need for novel and effective immunostimulants to overcome challenges, such as instability and autoinflammatory toxicity, associated with conventional immunostimulants. Nanotechnology provides the possibility to overcome these challenges. The well-known classical Chinese formula, Hwanglyeonhaedok-tang (HHT) has been widely used to treat immune-related diseases in clinical practice.

Methods

We developed novel gold nanoparticles (AuNPs) utilizing one-pot synthesis with the herbal formula-HHT. The optimal conditions for HHT-AuNP biosynthesis were established, and physicochemical properties of the optimized HHT-AuNPs were identified using various spectrometric and microscopic techniques. Bio-TEM analysis revealed that HHT-AuNPs were highly engulfed within RAW264.7 cells without inducing cytotoxicity. The effect of HHT-AuNPs on immunostimulatory activity was evaluated in innate and adaptive immune cells (RAW264.7 macrophages and ICR mice splenocytes) using qRT-PCR, immunoblotting, and ELISA.

Results

The HHT-AuNPs remarkably increased the nitric oxide (NO) and immune-related cytokines production by activating the mitogen-activated protein kinase (MAPK) and nuclear factor-κB (NF-κB) signaling pathways in RAW264.7 cells. Furthermore, HHT-AuNPs exerted immunostimulatory effects on mouse splenocytes by priming T/B-cells and macrophages.

Discussion

The present study is the first to demonstrate that HHT-AuNPs could be utilized as immunostimulators to activate both innate and adaptive immune systems. These results provide a foundation for the application of traditional Chinese medicinal formulae in the field of nanomedicine.

Rowan Berries: A Potential Source for Green Synthesis of Extremely Monodisperse Gold and Silver Nanoparticles and Their Antimicrobial Property

Rowanberries (Sorbus aucuparia) are omnipresent in Europe. The medicinal importance of rowanberries is widely known and corresponds to the active ingredients present in the fruits, mainly polyphenols, carotenoids, and organic acids. In the current study, we explored rowanberries for the reduction of gold and silver salts into nanoparticles. Rowanberries-mediated gold nanoparticles (RB-AuNPs) formed within 5 s at room temperature, and silver nanoparticles (RB-AgNPs) formed in 20 min at 90 °C. The produced nanoparticles were thoroughly characterized by UV-Vis spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), dynamic light scattering (DLS), single-particle inductively coupled plasma–mass spectrometry (sp-ICP-MS), thermogravimetric analysis (TGA), Fourier transform-infrared spectroscopy (FT-IR) and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF). The characterization confirmed that the nanoparticles are highly monodisperse, spherical, stable over long periods, and exhibit a high negative zeta potential values. The produced RB-AuNPs and RB-AgNPs were 90–100 nm and 20–30 nm in size with a thick biological corona layer surrounding them, providing extreme stability but lowering the antimicrobial activity. The antimicrobials study of RB-AgNPs revealed that the nanoparticles have antimicrobial potential with an MBC value of 100 µg/mL against P. aeruginosa and 200 µg/mL against E. coli.

Antibacterial, Antifungal, and Antioxidant Activities of Silver Nanoparticles Biosynthesized from Bauhinia tomentosa Linn

The biogenic synthesis of silver nanoparticles (AgNPs) has a wide range of applications in the pharmaceutical industry. Here, we synthesized AgNPs using the aqueous flower extract of Bauhinia tomentosa Linn. Formation of AgNPs was observed using ultraviolet-visible light spectrophotometry at different time intervals. Maximum absorption was observed after 4 h at 420 nm due to the reduction of Ag⁺ to Ag⁰. The stabilizing activity of functional groups was identified by Fourier-transform infrared spectroscopy. Size and surface morphology were also analyzed using scanning electron microscopy. The present study revealed the AgNPs were spherical in form with a diameter of 32 nm. The face-centered cubic structure of AgNPs was indexed using X-ray powder diffraction with peaks at 2θ = 37°, 49°, 63°, and 76° (corresponding to the planes of silver 111, 200, 220, 311), respectively. Energy-dispersive X-ray spectroscopy revealed that pure reduced silver (Ag⁰) was the major constituent (59.08%). Antimicrobial analyses showed that the biosynthesized AgNPs possess increased antibacterial activity (against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative), with larger zone formation against S. aureus (9.25 mm) compared with that of E. coli (6.75 mm)) and antifungal activity (against Aspergillus flavus and Candida albican (with superior inhibition against A. flavus (zone of inhibition: 7 mm) compared with C. albicans (zone of inhibition: 5.75 mm)). Inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was found to be dose-dependent with half-maximal inhibitory concentration (IC₅₀) values of 56.77 μg/mL and 43.03 μg/mL for AgNPs and ascorbic acid (control), respectively, thus confirming that silver nanoparticles have greater antioxidant activity than ascorbic acid. Molecular docking was used to determine the mode of antimicrobial interaction of our biosynthesized B. tomentosa Linn flower-powder extract-derived AgNPs. The biogenic AgNPs preferred hydrophobic contacts to inhibit bacterial and fungal sustainability with reducing antioxidant properties, suggesting that biogenic AgNPs can serve as effective medicinal agents.

Development of nanobiomaterial for wound healing based on silver nanoparticles loaded on chitosan hydrogel

The objective of this study was to develop nanobiomaterial containing silver nanoparticles (AgNPs) for wound healing. AgNPs were synthesized using Saussurea lappa (Sl) aqueous root extract as reducing agent and were characterized physico-chemically using UV-vis spectral studies, XRD, FESEM, TEM, FTIR spectral analysis, DLS, and TG-DSC. Sl AgNPs production was optimized using response surface methodology. The cytotoxicity of Sl AgNPs was assessed by THP1 cell lines, which showed that Sl AgNPs were nontoxic with an IC50 of 151.10 μg/mL at 24 h. For topical application, Sl AgNPs was loaded on chitosan hydrogel was characterized through spreadability, in vitro release, antibacterial activity, swelling behavior, and SEM analysis. The chitosan Sl AgNPs hydrogel was subjected acute dermal toxicity test using Wistar albino rats and was found to be nontoxic. The excisional wound model was created along with Pseudomonas aeruginosa as an inoculant in Wistar albino rats. The chitosan Sl AgNPs hydrogel treated rats showed excellent wound healing qualities, lower bacterial counts, and enhanced production of connective tissues. Our findings strongly suggest that AgNPs synthesized from Saussurea lappa root extract loaded on chitosan hydrogel possibly applied for the remedy of infectious wounds at a concentration of 0.1 mg of Sl AgNPs/g of hydrogel.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-03030-0.

Current approaches for the exploration of antimicrobial activities of nanoparticles

Infectious diseases of bacterial and viral origins contribute to substantial mortality worldwide. Collaborative efforts have been underway between academia and the industry to develop technologies for a more effective treatment for such diseases. Due to their utility in various industrial applications, nanoparticles (NPs) offer promising potential as antimicrobial agents against bacterial and viral infections. NPs have been established to possess potent antimicrobial activities against various types of pathogens due to their unique characteristics and cell-damaging ability through several mechanisms. The recently accepted antimicrobial mechanisms possessed by NPs include metal ion release, oxidative stress induction, and non-oxidative mechanisms. Another merit of NPs lies in the low likelihood of the development of microbial tolerance towards NPs, given the multiple simultaneous mechanisms of action against the pathogens targeting numerous gene mutations in these pathogens. Moreover, NPs provide a fascinating opportunity to curb microbial growth before infections: this outstanding feature has led to their utilization as active antimicrobial agents in different industrial applications, e.g. the coating of medical devices, incorporation in food packaging, promoting wound healing and encapsulation with other potential materials for wastewater treatment. This review discusses the progress and achievements in the antimicrobial applications of NPs, factors contributing to their actions, mechanisms underlying their efficiency, and risks of their applications, including the antimicrobial action of metal nanoclusters (NCs). The review concludes with a discussion of the restrictions on present studies and future prospects of nanotechnology-based NPs development.

Prospective Application of Nanoparticles Green Synthesized Using Medicinal Plant Extracts as Novel Nanomedicines

The use of medicinal plants in green synthesis of metal nanoparticles is increasing day by day. A simple search for the keywords "green synthesis" and "nanoparticles" yields more than 33,000 articles in Scopus. As of August 10, 2021, more than 4000 articles have been published in 2021 alone. Besides demonstrating the ease and environmental-friendly route of synthesizing nanomaterials, many studies report the superior pharmacological properties of green synthesized nanoparticles compared to those synthesized by other methods. This is probably due to the fact that bioactive molecules are entrapped on the surface of these nanoparticles. On the other hand, recent studies have confirmed the nano-dimension and biocompatibility of metal ash (Bhasma) preparations, which are commonly macerated with biological products and administered for the treatment of various diseases in Indian medicine since ancient times. This perspective article argues for the prospective medical application of green nanoparticles in the light of Bhasma.

Gold Nanoparticles Prepared with Phyllanthus emblica Fruit Extract and Bifidobacterium animalis subsp. lactis Can Induce Apoptosis via Mitochondrial Impairment with Inhibition of Autophagy in the Human Gastric Carcinoma Cell Line AGS

(1) Background: Nanotechnology is being widely applied for anticancer strategies with few side effects. Nanoparticles (NPs) prepared from natural extracts are promising candidates for cancer treatment because of their unique physicochemical characteristics. This study aimed to prepare gold nanoparticles (AuNPs) from Phyllanthus emblica fruit extract (PEFE) using Bifidobacterium animalis subsp. lactis (B. lactis) and to evaluate their anticancer activity against the human gastric adenocarcinoma cell-line (AGS). (2) Methods: The safety of microbial biosynthesis AuNPs (PEFE-AuNPs) was assessed by evaluating the cytotoxicity. The anticancer activity of PEFE-AuNPs was investigated in AGS cells in terms of apoptosis and autophagy. (3) Results: PEFE-AuNPs exhibited significant cytotoxicity against AGS cells but not against normal cells. The apoptosis induced by PEFE-AuNPs in AGS cells was associated with PTEN-induced kinase 1 (PINK1)-Parkin mediated reduction of mitochondrial membrane potential and activation of intracellular signaling apoptosis pathways. The anticancer activity of PEFE-AuNPs was associated with induction of apoptosis through inhibition of autophagy, downregulation of LC3-II/LC3-I and Beclin-1 expression, and upregulation of p62 expression in AGS cells. (4) Conclusions: This study is the first to demonstrate the anticancer activity of PEFE-AuNPs against AGS cells. Our results provide a good starting point for the development of new anticancer products based on gold nanoparticles of P. emblica fruit extract.

Biosynthetic gold nanoparticles of Hibiscus syriacus L. callus potentiates anti-inflammation efficacy via an autophagy-dependent mechanism

Biological applications of gold nanoparticles (AuNps) have potentially explored an efficient agent attributed to their biocompatibility and high efficiency in drug delivery. Our study applied an extract of Hibiscus syriacus L. callus (HCE) with a pioneer implementation on the induction of mass production. Bioactive compounds present in HCE were identified by Gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography MS (LC-MS), wherein, the Denatonium was exclusively identifiable in HCE. Next, AuNps were synthesized and optimized using HCE (HCE-AuNps), and the comparison was conducted to evaluate the anti-inflammatory effect in lipopolysaccharide (LPS)-stimulated macrophages. As per result, HCE-AuNps was reported to show a prominent reduction of pro-inflammatory cytokines and renovate the mitochondrial function through restoring the mitochondrial membrane potential changes, decreasing reactive oxygen species (ROS) accumulation, and recovering ATP contents, respectively. Furthermore, the immunoblotting of LC3b/a accumulation, and p62 rapid degradation revealed that HCE-AuNps could induce the autophagy as an intracellular response to reinforce alleviation of pro-inflammatory cytokines and mitochondria dysfunction. Besides, 740 Y-P (PI3K agonist) was used to verify that inhibiting autophagy could partially reverse HCE-AuNps suppressed mitochondrial dysfunction, and thus exacerbated inflammation, supporting a causal role for autophagy in the anti-inflammatory effect of HCE-AuNps. Taken together, we strongly anticipate that HCE-AuNps would act as a potential autophagy inducer for LPS-triggered macrophage's inflammation, providing a novel insight for biosynthetic nanoparticles in the treatment of mitochondria dysfunction and inflammation related diseases.

Biofabrication of AuNPs using Coriandrum sativum leaf extract and their antioxidant, analgesic activity

In this work, Gold nanoparticles (AuNPs) were synthesized by reducing aqueous Au metal ions upon interaction with Coriandrum sativum (C. sativum) leaf extract. The optical absorption peak for the synthesized AuNPs was obtained by using UV-visible spectroscopy within a range of 540-550 nm. The formation of diffraction peaks found at 2θ values of 78.00°, 66.05°, 44.85° and 38.48° that corresponds to the index planes (311), (220), (200), and (111) validate the effective synthesis of AuNPs. Transmission electron microscopy (TEM) was utilized to measure the size range of the spherical shaped nanoparticles, which is obtained to be 32.96 ± 5.25 nm. The peaks obtained from the FTIR results are closely linked to anthocyanins, benzophenones, flavonoids and phenols, which indicated that these biomolecules may serve as reducing agents. Additionally, studies of antioxidant function in vitro revealed that the activities of ABTS (2, 2'-azino-bis 3-ethylbenzthiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) were improved dose-dependently. Further, the results of analgesic analysis showed that the cumulative action of AuNPs and the C. sativum leaf extract in pain relief is more efficient than independent C. sativum leaf extract and the aspirin drug.

Cytotoxic Effect of Silver Nanoparticles Synthesized by Green Methods in Cancer

Cancer is a major public health problem, but despite the several treatment approaches available, patients develop resistance in short time periods, making overcoming resistance or finding more efficient treatments an imperative challenge. Silver nanoparticles (AgNPs) have been described as an alternative option due to their physicochemical properties. The scope of this review was to systematize the available scientific information concerning these characteristics in AgNPs synthesized according to green chemistry's recommendations as well as their cytotoxicity in different cancer models. This is the first paper analyzing, correlating, and summarizing AgNPs' main parameters that modulate their cellular effect, including size, shape, capping, and surface plasmon resonance profile, dose range, and exposure time. It highlights the strong dependence of AgNPs' cytotoxic effects on their characteristics and tumor model, making evident the strong need of standardization and full characterization. AgNPs' application in oncology research is a new, open, and promising field and needs additional studies.

A Bottom-Up Synthesis Approach to Silver Nanoparticles Induces Anti-Proliferative and Apoptotic Activities Against MCF-7, MCF-7/TAMR-1 and MCF-10A Human Breast Cell Lines

A bottom-up approach for synthesizing silver nanoparticles (AgNPs-GA) phytomediated by Garcinia atroviridis leaf extract is described. Under optimized conditions, the AgNPs-GA were synthesized at a concentration of 0.1 M silver salt and 10% (w/v) leaf extract, 1:4 mixing ratio of reactants, pH 3, temperature 32 °C and 72 h reaction time. The AgNPs-GA were characterized by various analytical techniques and their size was determined to be 5–30 nm. FTIR spectroscopy indicates the role of phenolic functional groups in the reduction of silver ions into AgNPs-GA and in supporting their subsequent stability. The UV-Visible spectrum showed an absorption peak at 450 nm which reflects the surface plasmon resonance (SPR) of AgNPs-GA and further supports the stability of these biosynthesized nanoparticles. SEM, TEM and XRD diffractogram analyses indicate that AgNPs-GA were spherical and face-centered-cubic in shape. This study also describes the efficacy of biosynthesized AgNPs-GA as anti-proliferative agent against human breast cancer cell lines, MCF-7 and MCF-7/TAMR-1. Our findings indicate that AgNPs-GA possess significant anti-proliferative effects against both the MCF-7 and MCF-7/TAMR-1 cell lines, with inhibitory concentration at 50% (IC₅₀ values) of 2.0 and 34.0 µg/mL, respectively, after 72 h of treatment. An induction of apoptosis was evidenced by flow cytometry using Annexin V-FITC and propidium iodide staining. Therefore, AgNPs-GA exhibited its anti-proliferative activity via apoptosis on MCF-7 and MCF-7/TAMR-1 breast cancer cells in vitro. Taken together, the leaf extract from Garcinia atroviridis was found to be highly capable of producing AgNPs-GA with favourable physicochemical and biological properties.

A Sustainable Approach for the Green Synthesis of Silver Nanoparticles from Solibacillus isronensis sp. and Their Application in Biofilm Inhibition

The use of bacteria as nanofactories for the green synthesis of nanoparticles is considered a sustainable approach, owing to the stability, biocompatibility, high yields and facile synthesis of nanoparticles. The green synthesis provides the coating or capping of biomolecules on nanoparticles surface, which confer their biological activity. In this study, we report green synthesis of silver nanoparticles (AgNPs) by an environmental isolate; named as AgNPs1, which showed 100% 16S rRNA sequence similarity with Solibacillus isronensis. UV/visible analysis (UV/Vis), transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR) were used to characterize the synthesized nanoparticles. The stable nature of nanoparticles was studied by thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS). Further, these nanoparticles were tested for biofilm inhibition against Escherichia coli and Pseudomonas aeruginosa. The AgNPs showed minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of 3.12 µg/mL and 6.25 µg/mL for E. coli, and 1.56 µg/mL and 3.12 µg/mL for P. aeruginosa, respectively.

Assessment of MMP29 Gene Expression and Silver Nanoparticles Effects on Colon Cancer Cell Line (HT29)

BACKGROUND

Colon cancer is a major cause of death around the world. The evaluation of novel approaches on corresponding genes would be a vital strategy toward eradication of cancer cells. In this study, the toxicity of silver nanoparticle on the colon cancer cell line (HT29) and expression of matrix metalloproteinase (MMP29) gene was investigated.

MATERIALS AND METHODS

The silver nanoparticle (AgNPs) was synthesized and assessed by transmission electron microscopy (TEM). The cytotoxicity of synthesized AgNP on the HT29 cell line was evaluated using the MTT assay. Furthermore, the expression of MMP29 gene was investigated by the quantitative real-time PCR (RT-qPCR).

RESULTS

The TEM results revealed that the fabricated AgNPs were mostly spherical in shape and had an average diameter of 22 nm. The results outlined that AgNPs significantly decreased the viability of cells in a dose- and time-dependent manner (p < 0.001). Additionally, we observed a significant difference among various concentrations.

CONCLUSION

The findings indicated that the green fabricated AgNPs have the potential as a promising approach toward the colon cancer therapy. Furthered studies are essential to evaluate against other cancer cell lines and genes participating in the cancer progress.

Citric Juice-mediated Synthesis of Tellurium Nanoparticles with Antimicrobial and Anticancer Properties

Bacterial infections and cancer are two of the most significant concerns that the current healthcare system should tackle nowadays. Green nanotechnology is presented as a feasible solution that is able to produce materials with significant anticancer and antibacterial activity, while overcoming the main limitations of traditional synthesis. In the present work, orange, lemon and lime extracts were used as both reducing and capping agents for the green synthesis of tellurium nanoparticles (TeNPs) using a microwave-assisted reaction. TeNPs showed a uniform size distribution, and rod- and cubic-shapes, and were extensively characterized in terms of morphology, structure and composition using TEM, SEM, XPS, XRD, FTIR and EDX analysis. TeNPs showed an important antibacterial activity against both Gram-negative and -positive bacteria in a range concentrations from 5 to 50 μg/mL over a 24-hour time period. Besides, nanoparticles showed anticancer effect towards human melanoma cells over 48 hours at concentrations up to 50 μg/mL. Moreover, the Te nanostructures showed no significant cytotoxic effect towards human dermal fibroblast at concentrations up to 50 μg/mL. Therefore, we present an environmentally-friendly and cost-effective synthesis of TeNPs using only fruit juices and showing enhanced and desirable biomedical properties towards both infectious diseases and cancer.

Green synthesis of gold nanoparticles using Euphrasia officinalisleaf extract to inhibit lipopolysaccharide-induced inflammation through NF-κB and JAK/STAT pathways in RAW 264.7 macrophages

Background

Gold nanoparticles (AuNPs) have potential applications in the treatment and diagnosis process, which are attributed to their biocompatibility and high efficiency of drug delivery. In the current study, we utilized an extract of Euphrasia officinalis, a traditional folk medicine, to synthesize gold nanoparticles (EO-AuNPs), and investigated their anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.

Materials and methods

The AuNPs were synthesized from an ethanol extract of E. officinalis leaves and characterized using several analytical techniques. Anti-inflammatory activities of EO-AuNPs were detected by a model of LPS-induced upregulation of inflammatory mediators and cytokines including nitric oxide (NO), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), IL-1β, and IL-6 in RAW 264.7 cells. The activation of nuclear factor (NF)-κB and Janus kinase/signal transducer and activators of transcription (JAK/STAT) signaling pathways was investigated by Western blot.

Results

The results confirmed the successful synthesis of AuNPs by E. officinalis. Transmission electron microscopy images showed obvious uptake of EO-AuNPs and internalization into intracellular membrane–bound compartments, resembling endosomes and lysosomes by RAW 264.7 cells. Cell viability assays showed that EO-AuNPs exhibited little cytotoxicity in RAW 264.7 cells at 100 µg/mL concentration after 24 hours. EO-AuNPs significantly suppressed the LPS-induced release of NO, TNF-α, IL-1β, and IL-6 as well as the expression of the iNOS gene and protein in RAW 264.7 cells. Further experiments demonstrated that pretreatment with EO-AuNPs significantly reduced the phosphorylation and degradation of inhibitor kappa B-alpha and inhibited the nuclear translocation of NF-κB p65. In addition, EO-AuNPs suppressed LPS-stimulated inflammation by blocking the activation of JAK/STAT pathway.

Conclusion

The synthesized EO-AuNPs showed anti-inflammatory activity in LPS-induced RAW 264.7 cells, suggesting they may be potential candidates for treating inflammatory-mediated diseases.

Anti-neuroinflammatory effects of Ephedra sinica Stapf extract-capped gold nanoparticles in microglia

Background: Combination therapy remains a promising strategy for treating neurodegenerative diseases, although green synthesis of gold nanoparticles for treating chronic neuroinflammation and studying their efficacy in treating neuroinflammation-mediated neurodegenerative diseases is not well assessed.

Results: Here, Ephedra sinica Stapf (ES) extract was used as the reducing, capping, and stabilizing agent for gold nanoparticle synthesis. We developed ES extract-capped gold nanoparticles (ES-GNs) and investigated their anti-neuroinflammatory properties in microglia. ES-GNs displayed maximum absorption at 538 nm in ultraviolet-visible spectroscopy. Dynamic light scattering assessment revealed that ES-GN diameter was 57.6±3.07 nm, with zeta potential value of −24.6±0.84 mV. High resolution–transmission electron microscopy confirmed the spherical shape and average diameter (35.04±4.02 nm) of ES-GNs. Crystalline structure of ES-GNs in optimal conditions was determined by X-ray powder diffraction, and elemental gold presence was confirmed by energy-dispersive X-ray spectroscopy. Fourier transform-infrared spectroscopy confirmed gold nanoparticle synthesis using ES. Anti-neuroinflammatory properties of ES-GNs on production of pro-inflammatory mediators (nitric oxide, prostaglandin E₂, and reactive oxygen species) and cytokines (tumor necrosis factor-α, IL-1β, and IL-6) in lipopolysaccharide (LPS)-stimulated microglia were investigated by ELISA and flow cytometry. ES-GNs significantly attenuated LPS-induced production of pro-inflammatory mediators and cytokines, which was related to suppressed transcription and translation of inducible nitric oxide synthase and cyclooxygenase-2, determined by RT-PCR and western blotting. ES-GNs downregulated upstream signaling pathways (IκB kinase-α/β, nuclear factor-κB, Janus-activated kinase /signal transducers and activators of transcription, mitogen-activated protein kinase , and phospholipase D) of pro-inflammatory mediators and cytokines in LPS-stimulated microglia. Anti-neuroinflammatory properties of ES-GNs were mediated by ES-GNs-induced AMP-activated protein kinase)-mediated nuclear erythroid 2-related factor 2 /antioxidant response element signaling.

Conclusion: Collectively, these findings provide a new insight on the role of ES-GNs in treating chronic neuroinflammation-induced neurodegenerative diseases.

Antimicrobial Effects of Biogenic Nanoparticles

Infectious diseases pose one of the greatest health challenges in the medical world. Though numerous antimicrobial drugs are commercially available, they often lack effectiveness against recently developed multidrug resistant (MDR) microorganisms. This results in high antibiotic dose administration and a need to develop new antibiotics, which in turn requires time, money, and labor investments. Recently, biogenic metallic nanoparticles have proven their effectiveness against MDR microorganisms, individually and in synergy with the current/conventional antibiotics. Importantly, biogenic nanoparticles are easy to produce, facile, biocompatible, and environmentally friendly in nature. In addition, biogenic nanoparticles are surrounded by capping layers, which provide them with biocompatibility and long-term stability. Moreover, these capping layers provide an active surface for interaction with biological components, facilitated by free active surface functional groups. These groups are available for modification, such as conjugation with antimicrobial drugs, genes, and peptides, in order to enhance their efficacy and delivery. This review summarizes the conventional antibiotic treatments and highlights the benefits of using nanoparticles in combating infectious diseases.

Green synthesis of gold and silver nanoparticles from Cannabis sativa (industrial hemp) and their capacity for biofilm inhibition

Background

Cannabis sativa (hemp) is a source of various biologically active compounds, for instance, cannabinoids, terpenes and phenolic compounds, which exhibit antibacterial, antifungal, anti-inflammatory and anticancer properties. With the purpose of expanding the auxiliary application of C. sativa in the field of bio-nanotechnology, we explored the plant for green and efficient synthesis of gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs).

Methods and results

The nanoparticles were synthesized by utilizing an aqueous extract of C. sativa stem separated into two different fractions (cortex and core [xylem part]) without any additional reducing, stabilizing and capping agents. In the synthesis of AuNPs using the cortex enriched in bast fibers, fiber-AuNPs (F-AuNPs) were achieved. When using the core part of the stem, which is enriched with phenolic compounds such as alkaloids and cannabinoids, core-AuNPs (C-AuNPs) and core-AgNPs (C-AgNPs) were formed. Synthesized nanoparticles were character-ized by UV–visible analysis, transmission electron microscopy, atomic force microscopy, dynamic light scattering, Fourier transform infrared, and matrix-assisted laser desorption/ionization time-of-flight. In addition, the stable nature of nanoparticles has been shown by thermogravimetric analysis and inductively coupled plasma mass spectrometry (ICP-MS). Finally, the AgNPs were explored for the inhibition of Pseudomonas aeruginosa and Escherichia coli biofilms.

Conclusion

The synthesized nanoparticles were crystalline with an average diameter between 12 and 18 nm for F-AuNPs and C-AuNPs and in the range of 20–40 nm for C-AgNPs. ICP-MS analysis revealed concentrations of synthesized nanoparticles as 0.7, 4.5 and 3.6 mg/mL for F-AuNPs, C-AuNPs and C-AgNPs, respectively. Fourier transform infrared spectroscopy revealed the presence of flavonoids, cannabinoids, terpenes and phenols on the nanoparticle surface, which could be responsible for reducing the salts to nanoparticles and further stabilizing them. In addition, the stable nature of synthesized nanoparticles has been shown by thermogravimetric analysis and ICP-MS. Finally, the AgNPs were explored for the inhibition of P. aeruginosa and E. coli biofilms. The nanoparticles exhibited minimum inhibitory concentration values of 6.25 and 5 µg/mL and minimum bactericidal concentration values of 12.5 and 25 µg/mL against P. aeruginosa and E. coli, respectively.

Bactericidal Properties of Plants-Derived Metal and Metal Oxide Nanoparticles (NPs)

Nanoparticles (NPs) are nano-sized particles (generally 1–100 nm) that can be synthesized through various methods. The wide range of physicochemical characteristics of NPs permit them to have diverse biological functions. These particles are versatile and can be adopted into various applications, particularly in biomedical field. In the past five years, NPs’ roles in biomedical applications have drawn considerable attentions, and novel NPs with improved functions and reduced toxicity are continuously increasing. Extensive studies have been carried out in evaluating antibacterial potentials of NPs. The promising antibacterial effects exhibited by NPs highlight the potential of developing them into future generation of antimicrobial agents. There are various methods to synthesize NPs, and each of the method has significant implication on the biological action of NPs. Among all synthetic methods, green technology is the least toxic biological route, which is particularly suitable for biomedical applications. This mini-review provides current update on the antibacterial effects of NPs synthesized by green technology using plants. Underlying challenges in developing NPs into future antibacterials in clinics are also discussed at the present review.

Rhizome of Anemarrhena asphodeloides as mediators of the eco-friendly synthesis of silver and gold spherical, face-centred cubic nanocrystals and its anti-migratory and cytotoxic potential in normal and cancer cell lines

The water extract of Anemarrhena asphodeloides, the traditional oriental medicinal plant, mediated the eco-friendly synthesis of silver nanoparticles (Aa-AgNPs) and gold nanoparticles (Aa-AuNPs). First, its therapeutic rhizome was powdered prior to water extraction and then silver, gold nanoparticles were synthesized. Aa-AgNPs and Aa-AuNPs were found to be spherical, face-centred cubic nanocrystals with a Z-average hydrodynamic diameter of 190 and 258 nm, respectively. In addition, proteins and aromatic biomolecules were the plausible players associated with the production and stabilization of Aa-AgNPs; instead, phenolic compounds were responsible for the synthesis and stability of Aa-AuNPs. In vitro cytotoxic analysis revealed that up to 50 μg.mL^-1 concentration Aa-AuNPs did not exhibit any toxicity on 3T3-L1, HT29 and MCF7 cell lines, while being specifically cytotoxic to A549 cell line. On the contrary, Aa-AgNPs displayed a significantly higher toxicity in comparison to Aa-AuNPs in all cell lines specially MCF7 cell line. Since cancer cells were more sensitive to Aa-Au/AgNPs treatments, further evaluation was done in order to determine their anticancer potential. Reactive oxygen species (ROS) generation was not affected by Aa-AuNPs, on the other hand, Aa-AgNPs treatment exhibited a higher potential to induce oxidative stress in A549 cells than HT29 and MCF7 cells. In addition, Aa-Ag/AuNPs reduced cell migration in A549 cells at 10 and 50 μg.mL^-1, respectively. So far, this is the only report uncovering the ability of A. asphodeloides to synthesize silver and gold nanoparticles with anticancer potential and also indirectly enabling its large-scale utilization with value addition.

In vitro anti-inflammatory activity of spherical silver nanoparticles and monodisperse hexagonal gold nanoparticles by fruit extract of Prunus serrulata: a green synthetic approach

Recently, green metal nanoparticles have received global attention owing to their economical synthesis, biocompatible nature, widespread biomedical and environmental applications. Current study demonstrates a sustainable approach for the green synthesis of silver nanoparticles (P-AgNPs) and gold nanoparticles (P-AuNPs) from P. serrulata fresh fruit extract. The silver and gold nanoparticles were synthesized in a very rapid, efficient and facile manner, within 50 min and 30 s at 80 °C, respectively. The nanoparticles were characterized by using visual observation, UV-Vis, FE-TEM, EDX, elemental mapping, FT-IR, XRD and DLS, which confirmed the formation of monodispersed, crystalline and stable nanoparticles. Further, we explored these nanoparticles for anti-inflammatory activity through inhibition of downstream NF-κB activation in macrophages (RAW264.7). We demonstrated that the nanoparticles reduced expression of inflammatory mediators such as nitric oxide (NO), prostaglandin E2 (PEG₂), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) was attenuated in lipopolysaccharide (LPS)-induced RAW264.7 cells. Furthermore, nanoparticles significantly suppressed LPS-induced activation of NF-κB signalling pathway via p38 MAPK in RAW 264.7 cells. To the best of our knowledge, this is the first report on the efficient green synthesis of P-AgNPs and P-AuNPs using P. serrulata fresh fruit extract and its in vitro anti-inflammatory effects. Collectively, our results suggest that P. serrulata fresh fruit extract is a green resource for the eco-friendly synthesis of P-AgNPs and P-AuNPs, which further can be utilized as a novel therapeutic agent for prevention and cure of inflammation due to their biocompatible nature.

Biosynthesis of gold and silver chloride nanoparticles mediated by Crataegus pinnatifida fruit extract: in vitro study of anti-inflammatory activities

This research article investigates the one-pot synthesis of gold and silver chloride nanoparticles functionalized by fruit extract of Crataegus pinnatifida as reducing and stabilizing agents and their possible roles as novel anti-inflammatory agents. Hawthorn (C. pinnatifida) fruits are increasingly popular as raw materials for functional foods and anti-inflammatory potential agents because of abundant flavonoids. The reduction of auric chloride and silver nitrate by the aqueous fruit extract led to the formation of gold and silver chloride nanoparticles. The nanoparticles were further characterized by field emission transmission electron microscopy indicated that CP-AuNps and CP-AgClNps were hexagonal and cubic shape, respectively. According to X-ray diffraction results, the average crystallite sizes of CP-AuNps and CP-AgClNps were 14.20 nm and 24.80 nm. The biosynthesized CP-AgClNps served as efficient antimicrobial agents against Escherichia coli and Staphylococcus aureus. Furthermore, CP-AuNps and CP-AgClNps enhanced the DPPH radical scavenging activity of the fruit extract. Lastly, MTT assay of nanoparticles demonstrated low toxicity in murine macrophage (RAW264.7). Biosynthesized nanoparticles also reduced the production of the inflammatory cytokines including nitric oxide and prostaglandin E2 in lipopolysaccharide-induced RAW264.7 cells. Altogether, these findings suggest that CP-AuNps and CP-AgClNps can be used as novel drug carriers or biosensors with intrinsic anti-inflammatory activity.

Asymmetric dumbbell-shaped silver nanoparticles and spherical gold nanoparticles green-synthesized by mangosteen (Garcinia mangostana) pericarp waste extracts

Mangosteen (Garcinia mangostana) pericarp waste extract was used to synthesize gold and silver nanoparticles by a green strategy. The extract was both a reducing and stabilizing agent during synthesis. Phytochemical screening of the extract was conducted to obtain information regarding the presence/absence of primary and secondary metabolites in the extract. The in vitro antioxidant activity results demonstrated that the extract had excellent antioxidant activity, which was comparable to a standard (butylated hydroxy toluene). Spherical gold nanoparticles (gold nanoparticles green synthesized by mangosteen pericarp extract [GM-AuNPs]) with an average size of 15.37±3.99 to 44.20±16.99 nm were observed in high-resolution transmission electron microscopy (HR-TEM) images. Most interestingly, the silver nanoparticles (silver nanoparticles green synthesized by mangosteen pericarp extract [GM-AgNPs]) had asymmetric nanodumbbell shapes where one tail grew from a spherical head. The average head size was measured to be 13.65±5.07 to 31.08±3.99 nm from HR-TEM images. The hydrodynamic size of both nanoparticles tended to increase with increasing extract concentration. Large negative zeta potentials (−18.92 to −34.77 mV) suggested that each nanoparticle solution possessed excellent colloidal stability. The reaction yields were 99.7% for GM-AuNPs and 82.8% for GM-AgNPs, which were assessed by inductively coupled plasma optical emission spectroscopy. A high-resolution X-ray diffraction pattern confirmed the face-centered cubic structure of both nanoparticles. Based on phytochemical screening and Fourier transform infrared spectra, the hydroxyl functional groups of carbohydrates, flavonoids, glycosides, and phenolic compounds were most likely involved in a reduction reaction of gold or silver salts to their corresponding nanoparticles. The in vitro cytotoxicity (based on a water-soluble tetrazolium assay) demonstrated that GM-AgNPs were toxic to both A549 (a human lung cancer cell) and NIH3T3 (a mouse fibroblast cell). The cytotoxicity of GM-AgNPs on A549 cells was related to apoptotic cell death. However, GM-AuNPs did not show any significant cytotoxicity to either cell. These results suggest that GM-AuNPs have the potential to be drug delivery vehicles or carriers for pharmaceutical and biomedical applications.