Cytotoxic Effects Of AgNPs Research Articles

Silver Nanoparticles: An Instantaneous Solution for Anticancer Activity against Human Liver (HepG2) and Breast (MCF-7) Cancer Cells

Cancer is a cataclysmic disease that affects not only the target organ, but also the whole body. Metal-based nanoparticles (NPs) have recently emerged as a better option for the treatment of this deadly disease. Accordingly, the present work describes a means to control the growth of cancer cells by using colloidal silver nanoparticles (AgNPs) processed via homemade solutions and the characterization of these materials. The AgNPs may become an instantaneous solution for the treatment of these deadly diseases and to minimize or remove these problems. The AgNPs exhibit excellent control of the growth rate of human liver (HepG2) and breast (MCF-7) cancer cells, even at a very low concentrations. The cytotoxic effects of AgNPs on HepG2 and MCF-7 cancer cells were dose dependent (2–200 μg/mL), as evaluated using MTT and NRU assays. The production of reactive oxygen species (ROS) was increased by 136% and 142% in HepG2 and MCF-7 cells treated with AgNPs, respectively. The quantitative polymerase chain reaction (qPCR) data for both cell types (HepG2 and MCF-7) after exposure to AgNPs showed up- and downregulation of the expression of apoptotic (p53, Bax, caspase-3) and anti-apoptotic (BCl2) genes; moreover, their roles were described. This work shows that NPs were successfully prepared and controlled the growth of both types of cancer cells.

Silver nanoparticles induce oxidative stress, apoptosis and impaired steroidogenesis in ovarian granulosa cells of cattle

There have been increased effects of silver nanoparticle (Ag-NPs) on livestock during the past decade, but data related to adverse effects of Ag-NPs on reproductive tissues are limited. In the present study, the possible cytotoxic effects of Ag-NPs on oxidant/antioxidant balance, apoptosis and steroid hormone production in ovarian granulosa cells of cattle were studied.Cultured granulosa cells were treated with 10 nm Ag-NPs at various concentrations (1–100 µg/ml) for 24 h, and cell toxicity, oxidant/antioxidant markers, reactive oxygen species (ROS) production, abundances of apoptotic/antiapoptotic and steroidogenesis related mRNA transcripts were determined. The amount of DNA fragmentation was also determined using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Results indicated treatment of granulosa cells with Ag-NPs induced an increase of reactive oxygen species production concomitant with increased malondialdehyde concentrations and decreased antioxidant enzyme activities. There was a maximal percentage of TUNEL+ cells (46.6%) after treatment with 50 and 100 µg/ml of Ag-NPs. The Ag-NPs could induce apoptosis in granulosa cells as indicated by the increase in caspase-3 activity, and larger abundance of BCL2 associated X (BAX) and lesser abundance of B-cell lymphoma 2 (BCL2) mRNA transcripts. The abundance of steroidogenic enzyme mRNA transcripts decreased concomitant with suppression of steroid hormone synthesis from Ag-NP-treated cells. Findings indicate silver nanoparticles (SNP) induce apoptosis and oxidative stress and change the pattern of steroid hormone synthesis in granulosa cells of cattle. The results indicate Ag-NPs may inhibit the function and viability of ovarian cells.

Biologically formed silver nanoparticles and in vitro study of their antimicrobial activities on resistant pathogens.

Background and Objectives:Silver nanoparticles (AgNPs) have been found to have multiple uses as antibacterial, antifungal and anti-biofilm agents because of their biological activities and safety. The present study was aimed to analyze the antimicrobial and anti-biofilm activities as well as the cytotoxic effect of AgNPs against different human pathogens.Materials and Methods:AgNPs were synthesized using cell free supernatants of Escherichia coli (ATCC 25922), Enterococcus faecalis (ATCC 19433), Pseudomonas aeruginosa (ATCC 27856), Enterobacter cloacae (ATCC 13047) and Penicillium oxalicum strain, then were analyzed using UV/Vis Spectral Analysis, Transmission electron microscopy (TEM). Scanning Electron Microscope (SEM) and Energy Dispersive-X-ray Spectroscopy (EDX) analysis. Antimicrobial activities of biosynthesized AgNPs were assessed with selected antimicrobial agents against multidrug resistant bacteria and candida. Anti-biofilm and cytotoxicity assays of these biosynthesized AgNPs were also done.Results:The synthesis of AgNPs were confirmed through observed color change and monitoring UV-Vis spectrum which showed homogeneous (little agglomeration) distribution of silver nanoparticles. TEM and SEM have shown that the particle size ranged from 13 to 34 (nm) with spherical shape and a high signal with EDX analysis. Antibacterial and antifungal efficacy of antibiotics and fluconazole were increased in combination with biosynthesized AgNPs against resistant bacteria and candida. Significant reduction in biofilm formation was found better with Penicillium oxalicum AgNPs against biofilm forming bacteria.Conclusion:Penicillium oxalicum has the best effect towards synthesizing AgNPs, for antimicrobial activities against resistant bacteria and candida, in addition to anti-biofilm activities against biofilm forming Staphylococcus aureus and E. coli and the safest cytotoxicity effect on (MRC-5) cell line.

Mycosynthesis of Silver Nanoparticles by Candida albicans Yeast and its Biological Applications.

This study conducted a mycosynthesis of silver nanoparticles (AgNPs) by Candida albicans supernatant. The mycosynthesized AgNPs were identified by color visualization, ultraviolet-visible (UV) spectroscopy device, X-ray diffraction (XRD), energy dispersive analysis of X-ray (EDX), field emission scanning electron microscope (FESEM), and zeta potential analysis. The UV-Vis spectroscopy examination has shown the highest absorbance (λmax) at the wavelength of 429 nanometers, which was the indicator of the creation of AgNPs. Furthermore, XRD showed the crystalline structure of AgNPs, and EDX revealed the weight percentage of silver atoms in the sample (82.4%). According to the FESEM, the morphology of AgNPs was spherical, and its size was 40.19 nanometers. Zeta potential analysis indicated that AgNPs were middling stable in the solution, and the zeta potential of AgNPs mycosynthesized by C. albicans was-23.02 mV. The cytotoxic effect of AgNPs against a human colon cancer cell line using MTT assay has shown the presence of toxic action against the cells, and no cytotoxic effect appears on the normal cells. The antioxidant activity of AgNPs using DPPH assay demonstrated 17.0%, 29.3%, 48.3%, 67.6%, and 83.6% at concentrations of 6.25, 12.5, 25, 50, and 100 µg/ml, respectively. The impact of AgNPs on the chromosomal pattern has also been studied. The importance of this study lies in the possibility of the synthesis of AgNPs using this yeast since most nanoparticle preparation methods utilize molds.

Green Synthesis of AgNPs() Ultilizing Delonix Regia Extract as Anticancer and Antimicrobial Agents**

AbstractSilver is an effective antimicrobial agent with low toxicity, which is important especially in the treatment of burn wounds where transient bacteremia is prevalent. In this research, the green method was employed to synthesis silver nanoparticles (AgNPs). The synthesized AgNPs were characterized using IR, XRD, DLS and UV/Visible Spectrophotometery. XRD pattern of AgNPs has a face‐centered cubic (FCC) form and crystalline lattice with a crystallite size of 12 nm. FT‐IR spectra indicate the functional groups of phytochemical compounds at Delonix regia extract DRE and AgNPs. DLS showed the distribution of average particle size of AgNPs that have 11 nm mean size of the particle. The prepared AgNPs were screened for their cytotoxic effect against colon carcinoma cells (HCT‐ 116 cell line), hepatic cellular carcinoma cells (HepG‐2) and breast carcinoma cells (MCF‐7). The cytotoxic effect of AgNPs is close to the cytotoxic effect of Doxorubicin standard drug. The toxicity of the AgNPs was tested on bacterial species such as Gm (+) positive bacteria (Bacillus subtilis) and Gm (‐) negative bacteria (Serrati amarcescence and Escherichia coli) and fungal species such as Candida albicans, Getrichm candidum and Aspergillus flavus. The antimicrobial activity of AgNPs was greater towards Gm (+) positive bacteria compared to Gm (‐) negative bacteria. These biological activities of the synthesized AgNPs could be promised to use it as a drug.

Biosynthesis and Chemical Characterization of Silver Nanoparticles Using Satureja Rechingeri Jamzad and Their Apoptotic Effects on AGS Gastric Cancer Cells

Since green synthesis of silver nanoparticles (AgNPs) is a simple, safe, cost-effective and eco-friendly method, AgNPs appear to be promising anti-cancer agents in the medical field. In this study, the biosynthesis of AgNPs was performed using aqueous extract of Satureja rechingeri Jamzad. Their anti-cancer activity was evaluated on the AGS gastric cancer cell line. The characteristics of the AgNPs were evaluated and approved by transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV–visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR) and Dynamic light scattering (DLS). The cytotoxic effect of AgNPs on the AGS cell line was evaluated by MTT assay for 24 h. Flow cytometry technique was performed to evaluate apoptosis using AnnexinV-FITC kit as well as cell cycle analysis. The expression of pro-apoptotic and anti-apoptotic genes was evaluated using Real-Time PCR. The average size of AgNPs was calculated at 62 ± 1 nm. The biosynthesized nanoparticles inhibited AGS cell growth in a time- and dose-dependent manner. Flow cytometry results confirmed apoptotic cell death. Also biosynthesized AgNPs caused up-regulation of pro-apoptotic genes; caspase-3, caspase-9 and Bax and down-regulation of Bcl2 gene and inhibited the expression of cyclin D1 and cyclin E genes. The cell cycle analysis revealed the cancer cells arrest in the G0/G1 phase. It appears that AgNPs synthesized by Satureja rechingeri Jamzad have a high potential for use as an anti-cancer drug for the treatment of gastric cancer.

Silver nanoparticles biosynthesized by Anabaena flos-aquae enhance the apoptosis in breast cancer cell line

Silver nanoparticles (AgNPs) are one of the new cancer treatment tools due to their unique properties that enhance potential therapeutic efficacy. In this study, we describe the extracellular biosynthesis and anticancer activity of AgNPs using the Anabaena flos-aquae biomass extract as reducing agent. The formation of dark-brown $$\hbox {AgNO}_{{3}}$$ /extract solution confirmed the reduction of silver ions into AgNPs. In addition, the ultraviolet–visible spectroscopy showed the surface plasmon peak at 425 nm as characteristic peak for AgNPs. Transmission electron microscopy and scanning electron microscopy showed highly stable and mostly spherical AgNPs with average size of 5–25 nm. Fourier transform infrared spectral analysis confirmed the presence of biomolecules in the extract involved in the reduction and stabilization of AgNPs. In vitro, study of anticancer and cytotoxic effect of AgNPs and extract against T47D cell lines by MTT assay and flow cytometry confirmed the anti-proliferation potential of AgNPs against breast cancer cells. In conclusion, our results revealed that Anabaena can be used as a good organism for biologically synthesis of AgNPs and confirmed the potent therapeutic value of these nanoparticles as anticancer drugs.

A novel, green, rapid, nonchemical route hydrothermal assisted biosynthesis of Ag nanomaterial by blushwood berry extract and evaluation of its diverse applications

Silver nanoparticles (Ag Nps) were synthesised using blushwood berry seeds extract as a reducing agent via hydrothermal route. The synthesized nanoparticles were characterized by XRD, UV–vis, SEM, EDAX and TEM analysis. Moreover, silver nanoparticles were tested for photoluminescence, photocatalytic, antibacterial and anticancer studies. The TEM images clearly reveal the average particle size of 30 nm. Furthermore, photocatalytic degradation of methylene blue by Ag Nps has shown good photocatalytic activity. The photoluminescence studies for the synthesized material exhibited yellow emission by exciting at 436 nm. Antibacterial activity of the Ag Nps were carried out by disc diffusion method against both gram-positive and gram-negative bacterial strains. Ag Nps show the significant antioxidant activity through scavenging of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals. Furthermore, in vitro studies revealed dose-dependent cytotoxic effects of Ag Nps treated MCF-7, A549 and PC-3 cell lines. This is the first report on the hydrothermal synthesis of Ag Nps using blushwood berry extract. Results of present study could contribute to synthesize new and cost-effective drugs from blushwood berry using Ag Nps as nanocatalyst by green approach.

Callus Extract Mediated Green Synthesis of Silver Nanoparticles, Their Characterization and Cytotoxicity Evaluation Against MDA-MB-231 and PC-3 Cells

The green synthesis of nanoparticles using callus extract as reducing agent is an eco-friendly, cost-effective approach. In the present study, silver nanoparticles (AgNPs) were prepared using aqueous callus extract of Hyptis suaveolens and their cytotoxic efficacy against cancer cells namely MDA-MB-231 and PC-3 was reported. Callus growth was observed on Murashige and Skoog (MS) medium supplemented with (BAP) benzylaminopurine (0.5 mg/L) + naphthalene acetic acid (NAA) (2 mg/L), and 45-day-old callus was used as a source for synthesis of AgNPs. The synthesis of AgNPs was identified initially by color change (yellow to brown) of the reaction mixture and was further confirmed by characteristic UV–visible surface plasmon resonance peak at 447 nm. The presence of elemental silver in synthesized AgNPs was confirmed through Energy dispersive X-ray spectroscopy (EDS). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis revealed randomly dispersed, spherical shaped AgNPs, with size ranging from 12 to 25 nm, and the mean particle diameter is 18 ± 4 nm. Crystalline and monophasic nature of AgNPs was identified using XRD studies and distinct Bragg diffraction peaks corresponding to the planes of face-centered cubic lattice. The hydrodynamic diameter measured by dynamic light scattering was 207 nm, and it is higher than TEM and XRD analyses. The zeta potential of AgNPs in water was found to be − 24.5 mV, reflecting their higher stability, and FTIR revealed the presence of phenolic compounds and proteins. The cytotoxic effects of AgNPs against MDA-MB-231 and PC-3 cells were evaluated and their IC50 values were found to be 74.66 and 173.21 μg/mL, respectively. The results of the present study clearly demonstrate that the AgNPs prepared from Hyptis suaveolens have the potential to exert cytotoxic effect on cancer cell lines.

Green synthesis of silver nanoparticles via Cynara scolymus leaf extracts: The characterization, anticancer potential with photodynamic therapy in MCF7 cells.

In this study, we report on the synthesis of silver nanoparticles (AgNPs) from the leaf extracts of Cynara scolymus (Artichoke) using microwave irradiation and the evaluation of its anti-cancer potential with photodynamic therapy (PDT). Silver nanoparticles formation was characterized by scanning electron microscopy with energy dispersive x-ray spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Silver nanoparticles formation was also investigated the surface charge, particle size and distribution using zetasizer analysis. The cytotoxic effect of AgNPs and/or PDT was studied by MTT assay and migration by the scratch assay. The apoptotic inducing ability of the AgNPs and/or PDT was investigated by intracellular ROS analysis, antioxidant enzyme levels (SOD, CAT, GPx and GSH), Hoechst staining and Bax/Bcl-2 analysis using western blotting. The mean particle size of produced AgNPs was found 98.47±2.04 nm with low polydispersity (0.301±0.033). Zeta potential values of AgNPs show -32.3± 0.8 mV. These results clearly indicate the successful formation of AgNPs for cellular uptake. Mitochondrial damage and intracellular ROS production were observed upon treatment with AgNPs (10μg/mL) and PDT (0.5 mJ/cm2) showed significant reducing cell migration, expression of Bax and suppression of Bcl-2. Significantly, biosynthesized AgNPs showed a broad-spectrum anti-cancer activity with PDT therapy and therefore represent promoting ROS generation by modulating mitochondrial apoptosis induction in MCF7 breast cancer cells.

Extracellular Biosynthesis, Characterization and Cytotoxic Effect of Silver Nanoparticles by Streptomyces coelicoflavus KS-3.

The present work aimed to investigate extracellular biosynthesis of silver nanoparticles (AgNPs) mediated by an actinomycete strain and their cytotoxic effects compared with silver ions. The selected strain was identified as Streptomyces coelicoflavus KS-3 by phenotypical characteristics and 16S rRNA analysis. The formation of biosynthesized AgNPs was proved by an absorption peak observed at 437 nm. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) analyses revealed that the prepared AgNPs were spherical or approximately spherical followed by a small amount of truncated triangular, quadrangular and hexagonal with the particle diameters ranging from 2.33 to 91.3 nm. X-ray diffraction (XRD) pattern confirmed that the AgNPs presented a face-centered cubic (FCC) structure of crystalline silver. Energy dispersive of X-ray (EDX) spectrum and Fourier transform infrared spectroscopy (FTIR) analyses verified the existence of biomolecules, such as proteins, that participated in the formation and stabilization of AgNPs. Furthermore, the comparative study on cytotoxic effect of AgNPs indicated that the AgNPs exhibited higher biocompatibility towards human bronchial epithelial (HBE) cells than silver ions and exerted potent cytotoxic effect in a dose-dependent manner against human lung squamous cell carcinoma cells (HTB-182) and human lung adenocarcinoma cells (A549) with the concentrations ranging from 1 to 50 μg/mL.

Concentration- and Time-Dependent Cytotoxicity of Silver Nanoparticles on Normal Human Skin Fibroblast Cell Line

Background: A wide use of Silver Nanoparticles (AgNPs) in consumer products, industry, pharmaceuticals, and medical sciences, including dermatology, has always caused concerns related to its adverse effects on the environment and human safety. Nano-sized particles can be uptaken by the body through various routes, especially the skin, which is the widest organ and the first contact surface for different nanomaterials and other foreign agents. Objectives: The aim of this investigation was to assess the viability of a vulnerable normal skin cell line to cytotoxicity of AgNPs with the same effective size and concentrations used for various microbial agents, such as Candida species. Methods: Synthesized AgNPs were characterized using UV-visible absorption spectroscopy, X-ray diffraction, Dynamic Light Scattering (DLS), and Transmission Electron Microscopy (TEM). Different concentrations of the aqueous colloidal AgNPs (2.17 to 69.5 µg/mL) were tested on normal Human Skin Fibroblast (HSF) cell line using MTT assay after 24 and 48 hours of exposure. Results: The analysis demonstrated that the synthesized AgNPs were mainly spherical with an average size of 6.03 nm. The MTT findings showed a significant concentration- and time-dependent manner in the reduction of cell viability. The calculated IC50 values were 30.64 and 14.98 µg/mL for 24 and 48 hours of incubation, respectively. Conclusions: The cytotoxic effect of AgNPs was higher for Human Skin Fibroblast cells after 48 hours of exposure compared with 24 hours. According to the observed results, small nano-sized silver particles could potentially have cytotoxic effects on normal cells, especially at high concentrations and prolonged exposure times.

Antimicrobial and cytotoxic activity of silver nanoparticles synthesized from two haloalkaliphilic actinobacterial strains alone and in combination with antibiotics.

Presently, the effective antimicrobial agents have been limited by the emergence of microbial strains with multidrug resistance and biofilm formation potential. In the present study, we report remarkable antimicrobial activity of silver nanoparticles (AgNPs) synthesized from Streptomyces calidiresistens IF11 and IF17 strains, including inhibition of biofilm formation and synergistic effect of AgNPs and antibiotics against selected bacteria and yeasts. Cytotoxic effect of AgNPs on mammalian cell lines was also evaluated. Analysis of biosynthesized AgNPs by Fourier Transform Infrared Spectroscopy and transmission electron microscopy revealed their spherical shape, small size in the range of 5-50 and 5-20nm, respectively, as well as the presence of capping agents. Study of antimicrobial activity of AgNPs against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Candida albicans and Malassezia furfur evaluated by minimum inhibitory concentration (MIC) and minimum biocidal concentration (MBC) assays revealed that MICs of AgNPs from IF11 and IF17 strains against bacteria and yeasts were found to be in the range of 16-128 and 8-256μgml-1 , while MBCs were in the range of 48-192 and 32-256μgml-1 respectively. AgNPs inhibited biofilm formation of microbial strains, which was tested by using crystal violet stain. The highest synergistic effect determined by fractional inhibitory index of AgNPs with antibiotic (kanamycin or tetracycline) was found against Staph. aureus; while in case of yeasts, M. furfur showed highest sensitivity to AgNPs-ketoconazole combination (FIC=0·12). The cytotoxic activity of AgNPs towards HeLa and 3T3 cell lines was studied by MTT assay. The IC50 of AgNPs estimated against mouse fibroblasts was found to be 8·3 and 28·3μgml-1 and, against HeLa cell line, 28·5 and 53·8μgml-1 respectively. It can be concluded that AgNPs synthesized from S. calidiresistens IF11 and IF17 strains have potential as an effective antimicrobial and cytotoxic agent, especially when used in combination with antibiotics/antifungal agents. This study indicates potential application of biogenic silver nanoparticles as an antimicrobial agent in nanomedicine.

Role of Oxidative and Nitro-Oxidative Damage in Silver Nanoparticles Cytotoxic Effect against Human Pancreatic Ductal Adenocarcinoma Cells.

Pancreatic ductal adenocarcinoma is one of the most aggressive human malignancies, where the 5-year survival rate is less than 4% worldwide. Successful treatment of pancreatic cancer is a challenge for today's oncology. Several studies showed that increased levels of oxidative stress may cause cancer cells damage and death. Therefore, we hypothesized that oxidative as well as nitro-oxidative stress is one of the mechanisms inducing pancreatic cancer programmed cell death. We decided to use silver nanoparticles (AgNPs) (2.6 and 18 nm) as a key factor triggering the reactive oxygen species (ROS) and reactive nitrogen species (RNS) in pancreatic ductal adenocarcinoma cells (PANC-1). Previously, we have found that AgNPs induced PANC-1 cells death. Furthermore, it is known that AgNPs may induce an accumulation of ROS and alteration of antioxidant systems in different type of tumors, and they are indicated as promising agents for cancer therapy. Then, the aim of our study was to evaluate the implication of oxidative and nitro-oxidative stress in this cytotoxic effect of AgNPs against PANC-1 cells. We determined AgNP-induced increase of ROS level in PANC-1 cells and pancreatic noncancer cell (hTERT-HPNE) for comparison purposes. We found that the increase was lower in noncancer cells. Reduction of mitochondrial membrane potential and changes in the cell cycle were also observed. Additionally, we determined the increase in RNS level: nitric oxide (NO) and nitric dioxide (NO2) in PANC-1 cells, together with increase in family of nitric oxide synthases (iNOS, eNOS, and nNOS) at protein and mRNA level. Disturbance of antioxidant enzymes: superoxide dismutase (SOD1, SOD2, and SOD3), glutathione peroxidase (GPX-4) and catalase (CAT) were proved at protein and mRNA level. Moreover, we showed cells ultrastructural changes, characteristic for oxidative damage. Summarizing, oxidative and nitro-oxidative stress and mitochondrial disruption are implicated in AgNPs-mediated death in human pancreatic ductal adenocarcinoma cells.

Mutagenicity of silver nanoparticles in CHO cells dependent on particle surface functionalization and metabolic activation

The potential of engineered nanomaterials to induce genotoxic effects is an important aspect of hazard identification. In this study, cytotoxicity and mutagenicity as a function of metabolic activation of three silver nanoparticle (AgNP) preparations differing in surface coating were determined in Chinese hamster ovary (CHO) subclone K1 cells. Three silver nanoparticle preparations (x 90,0 <30 nm) stabilized with polyoxyethylene glycerol trioleate and polyoxyethylene sorbitan monolaurate (AgPure™), citrate (Citrate-Ag), and polyvinylpyrrolidone (PVP-Ag) were used for the experiments. The cytotoxic effect of AgNPs was assessed with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide) test using different concentrations of nanoparticles, while the mutagenicity was evaluated using the hypoxanthine-guanine phosphoribosyltransferase (HPRT) gene mutation assay. The cytotoxicity of all three AgNPs was lower in a cell culture medium containing 10% fetal calf serum (FCS) than in medium without FCS. The HPRT test without metabolic activation system S9 revealed that compared to the other AgNP formulations, citrate-coated Ag showed a lower genotoxic effect. However, addition of S9 increased the mutation frequency of all AgNPs and especially influenced the genotoxicity of Citrate-Ag. The results showed that exogenous metabolic activation of nanosilver is crucial even if interactions of the metabolic activation system, nanosilver, and cells are not really understood up to now.

Silver nanoparticles: Antimicrobial activity, cytotoxicity, and synergism with N-acetyl cysteine.

The fast progression of nanotechnology has led to novel therapeutic interventions. Antimicrobial activities of silver nanoparticles (Ag NPs) were tested against standard ATCC strains of Staphylococcus aureus (ATCC 9144), Escherichia coli (O157:H7), Pseudomonas aeruginosa (ATCC 27853), and Candida albicans (ATCC 90028) in addition to 60 clinical isolates collected from cancer patients. Antimicrobial activity was tested by disk diffusion method and MIC values for Ag NPs alone and in combination with N-acetylcysteine (NAC) against tested pathogens were determined by broth microdilution method. Ag NPs showed a robust antimicrobial activity against all tested pathogens and NAC substantially enhanced the antimicrobial activity of Ag NPs against all tested pathogens. Synergism between Ag NPs and NAC has been confirmed by checkerboard assay. The effect of Ag NPs on tested pathogens was further scrutinized by Transmission Electron Microscope (TEM) which showed disruption of cell wall in both bacteria and fungi. Ag NPs abrogated the activity of respiratory chain dehydrogenase of all tested pathogens and released muramic acid content from S. aureus in culture. The cytotoxic effect of Ag NPs alone and in combination with NAC was examined using human HepG2 cells and this revealed no cytotoxicity at MIC values of Ag NPs and interestingly, NAC reduced the cytotoxic effect of Ag NPs at concentrations higher than their MIC values. Taken together, Ag NPs have robust antimicrobial activity and NAC substantially enhances their antimicrobial activities against MDR pathogens which would provide a novel safe, effective, and inexpensive therapeutic approach to control the prevalence of MDR pathogens.

Silver nanoparticles suppresses brain-derived neurotrophic factor-induced cell survival in the human neuroblastoma cell line SH-SY5Y

Abstract Silver nanoparticles (AgNPs) are used as cytotoxic agents in various cancer cell lines; however, the cytotoxic effects of AgNPs on human neuroblastoma cells remain poorly understood. Here we report the mechanisms of action of AgNPs on brain-derived neurotrophic factor (BDNF) activation in human neuroblastoma cells using AgNPs. The results from biochemical, cellular and western blot analysis indicated that AgNPs significantly inhibit BDNF induced cell survival by enhanced leakage of lactate dehydrogenase, activation of reactive oxygen species, DNA damage, and modulation of various signaling molecules. Thus, AgNPs could serve as a potential candidate for developing novel therapeutic molecules for cancers.

Integrative analysis of genes and miRNA alterations in human embryonic stem cells-derived neural cells after exposure to silver nanoparticles

Given the rapid growth of engineered and customer products made of silver nanoparticles (Ag NPs), understanding their biological and toxicological effects on humans is critically important. The molecular developmental neurotoxic effects associated with exposure to Ag NPs were analyzed at the physiological and molecular levels, using an alternative cell model: human embryonic stem cell (hESC)-derived neural stem/progenitor cells (NPCs). In this study, the cytotoxic effects of Ag NPs (10–200μg/ml) were examined in these hESC-derived NPCs, which have a capacity for neurogenesis in vitro, at 6 and 24h. The results showed that Ag NPs evoked significant toxicity in hESC-derived NPCs at 24h in a dose-dependent manner. In addition, Ag NPs induced cell cycle arrest and apoptosis following a significant increase in oxidative stress in these cells. To further clarify the molecular mechanisms of the toxicological effects of Ag NPs at the transcriptional and post-transcriptional levels, the global expression profiles of genes and miRNAs were analyzed in hESC-derived NPCs after Ag NP exposure. The results showed that Ag NPs induced oxidative stress and dysfunctional neurogenesis at the molecular level in hESC-derived NPCs. Based on this hESC-derived neural cell model, these findings have increased our understanding of the molecular events underlying developmental neurotoxicity induced by Ag NPs in humans.

The effect of silver nanoparticles (AgNPs) on proliferation and apoptosis of in ovo cultured glioblastoma multiforme (GBM) cells.

Recently, it has been shown that silver nanoparticles (AgNPs) provide a unique approach to the treatment of tumors, especially those of neuroepithelial origin. Thus, the aim of this study was to evaluate the impact of AgNPs on proliferation and activation of the intrinsic apoptotic pathway of glioblastoma multiforme (GBM) cells cultured in an in ovo model. Human GBM cells, line U-87, were placed on chicken embryo chorioallantoic membrane. After 8 days, the tumors were divided into three groups: control (non-treated), treated with colloidal AgNPs (40 μg/ml), and placebo (tumors supplemented with vehicle only). At the end of the experiment, all tumors were isolated. Assessment of cell proliferation and cell apoptosis was estimated by histological, immunohistochemical, and Western blot analyses. The results show that AgNPs can influence GBM growth. AgNPs inhibit proliferation of GBM cells and seem to have proapoptotic properties. Although there were statistically significant differences between control and AgNP groups in the AI and the levels of active caspase 9 and active caspase 3, the level of these proteins in GBM cells treated with AgNPs seems to be on the border between the spontaneous apoptosis and the induced. Our results indicate that the antiproliferative properties of silver nanoparticles overwhelm proapoptotic ones. Further research focused on the cytotoxic effect of AgNPs on tumor and normal cells should be conducted.Electronic supplementary materialThe online version of this article (doi:10.1186/s11671-015-0823-5) contains supplementary material, which is available to authorized users.

The green synthesis, characterization, and evaluation of the biological activities of silver nanoparticles synthesized from Leptadenia reticulata leaf extract

Biosynthesis of silver nanoparticles (Ag Nps) was carried out using methanol leaves extract of L. reticulata. Ag Nps were characterized based on the observations of UV–visible spectroscopy, transmission electron microscopy, and X-ray diffraction (XRD) analysis. These Ag Nps were tested for antimicrobial activity by agar well diffusion method against different pathogenic microorganisms and antioxidant activity was performed using DPPH assay. Further, the in vitro cytotoxic effects of Ag Nps were screened against HCT15 cancer cell line and viability of tumor cells was confirmed using MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a yellow tetrazole)) assay. The nuclear condensation was studied using the propidium iodide-staining method. The color change from green to dark brown and the absorbance peak at about 420 nm indicated the formation of nanoparticles. XRD pattern showed characteristic peaks indexed to the crystalline planes (111), (200) and (220) of face-centered cubic silver. The nanoparticles were of spherical shape with varying sizes ranging from 50 to 70 nm. Biosynthesized Ag Nps showed potent antibacterial activity and effective radical scavenging activity. MTT assay revealed a dose-dependent decrease in cell viability. Microscopic observations showed distinct cellular morphological changes indicating unhealthy cells, whereas the control appeared normal. Increase in the number of propidium iodide positive cells were observed in maximum concentration. Methanolic leaf extract of L. reticulata acts as an excellent capping agent for the formation of silver nanoparticles and demonstrates immense biological activities. Hence, these Ag NPs can be used as antibacterial, antioxidant as well as cytotoxic agent in treating many medical complications.