Angiogenesis, the growth of new blood vessels from pre-existing vasculature is of physiological and pathological importance. We have investigated the anti-angiogenic potential of silver nanoparticles, produced by Bacillus licheniformis. Bovine retinal endothelial cells (BRECs) were treated with the different concentrations of silver nanoparticles for 24 h in the presence and absence of vascular endothelial growth factor (VEGF), where 500 nM (IC50) of silver nanoparticle concentration, was able to block the proliferation and migration of BRECs. The cells showed a clear enhancement in caspase-3 activity and formation of DNA ladders, evidence of induction of apoptosis. Here we report for the first time that silver nanoparticles inhibit cell survival via PI3K/Akt dependent pathway in Bovine retinal endothelial cells.
"Earlier studies reported that synthesis of bio-AgNPs by treating the culture supernatant of E. coli and Bacillus licheniformis with AgNO3 produced bio-AgNPs with an average diameter of 50 nm. These bio-AgNPs have been used for both in vitro and in vivo studies [36-38]. AgNPs with a size of 20 nm or less could enter the cell without significant endocytosis and are distributed within the cytoplasm . "
[Show abstract][Hide abstract] ABSTRACT: The goal of the present study was to investigate the toxicity of biologically prepared small size of silver nanoparticles in human lung epithelial adenocarcinoma cells A549. Herein, we describe a facile method for the synthesis of silver nanoparticles by treating the supernatant from a culture of Escherichia coli with silver nitrate. The formation of silver nanoparticles was characterized using various analytical techniques. The results from UV-visible (UV-vis) spectroscopy and X-ray diffraction analysis show a characteristic strong resonance centered at 420 nm and a single crystalline nature, respectively. Fourier transform infrared spectroscopy confirmed the possible bio-molecules responsible for the reduction of silver from silver nitrate into nanoparticles. The particle size analyzer and transmission electron microscopy results suggest that silver nanoparticles are spherical in shape with an average diameter of 15 nm. The results derived from in vitro studies showed a concentration-dependent decrease in cell viability when A549 cells were exposed to silver nanoparticles. This decrease in cell viability corresponded to increased leakage of lactate dehydrogenase (LDH), increased intracellular reactive oxygen species generation (ROS), and decreased mitochondrial transmembrane potential (MTP). Furthermore, uptake and intracellular localization of silver nanoparticles were observed and were accompanied by accumulation of autophagosomes and autolysosomes in A549 cells. The results indicate that silver nanoparticles play a significant role in apoptosis. Interestingly, biologically synthesized silver nanoparticles showed more potent cytotoxicity at the concentrations tested compared to that shown by chemically synthesized silver nanoparticles. Therefore, our results demonstrated that human lung epithelial A549 cells could provide a valuable model to assess the cytotoxicity of silver nanoparticles.
Nanoscale Research Letters 09/2014; 9(1):459. DOI:10.1186/1556-276X-9-459 · 2.78 Impact Factor
"Silver nanoparticles have (AgNPs) been shown various therapeutic effects such as antimicrobial, antifungal, antioxidant, and antiinflammatory effects (Tian et al. 2007). Silver NPs have been shown to induce the apoptotic pathway in vitro through free oxygen radical generation also showed antitumor, antiproliferative, and antiangiogenic effect in vitro (Rani et al. 2009; Park et al. 2010; Kalishwaralal et al. 2009). AgNPs have gained increasing interest in the field of nanomedicine due to their unique properties and obvious therapeutic potential in treating a variety of diseases, including retinal neovascularization and acquired immunodeficiency syndrome due to human immunodeficiency virus. "
[Show abstract][Hide abstract] ABSTRACT: Silver nanoparticles (AgNPs) were biologically synthesized using aqueous extract of Agaricus bisporus fungi. Physicochemical analysis of silver nanoparticles revealed that they are of spherical shape ranged size of 8–20 nm, and their zeta potential equal −7.23 mV. Silver nanoparticles showed a dose-dependent cytotoxic effect on MCF-7 breast cancer cells with LD50 (50 μg/ml). Mice bearing Ehrlich solid tumor treated with AgNPs and exposed to gamma radiation significantly ameliorated superoxide dismutase and catalase activity and reduced glutathione with an increase in malondialdehyde and nitric oxide levels compared to tumor group. Gamma radiation with AgNPs induced apoptotic cell count in Ehrlich solid tumor cells from 68.3 (treated with AgNPs) to 98.1 % (treated with AgNPs with gamma radiation) via a mechanism involved caspase-3. Histological sections of tumor tissue of mice treated with AgNPs showed antiangiogenesis effect of AgNPs. The overall result indicates that AgNPs synergize with gamma radiation, promising a potential combined therapy of cancer.
Cancer Nanotechnology 08/2013; 4(4-5). DOI:10.1007/s12645-013-0038-3
"Figure 9 clearly indicates that the DNA " laddering " pattern in MDA-MB-231 cells treated with AgNPs is one of the reasons for cell death. Earlier studies by Gurunathan and coworkers demonstrated that both cancer and noncancer cell lines treated with silver nanoparticle exhibit the formation of DNA ladder  . The deposition of metal particles inside the nucleus could affect the DNA and cell division. "
[Show abstract][Hide abstract] ABSTRACT: Silver nanoparticles (AgNPs) have been used as an antimicrobial and disinfectant agents. However, there is limited information about antitumor potential. Therefore, this study focused on determining cytotoxic effects of AgNPs on MDA-MB-231 breast cancer cells and its mechanism of cell death. Herein, we developed a green method for synthesis of AgNPs using culture supernatant of Bacillus funiculus, and synthesized AgNPs were characterized by various analytical techniques such as UV-visible spectrophotometer, particle size analyzer, and transmission electron microscopy (TEM). The toxicity was evaluated using cell viability, metabolic activity, and oxidative stress. MDA-MB-231 breast cancer cells were treated with various concentrations of AgNPs (5 to 25 μ g/mL) for 24 h. We found that AgNPs inhibited the growth in a dose-dependent manner using MTT assay. AgNPs showed dose-dependent cytotoxicity against MDA-MB-231 cells through activation of the lactate dehydrogenase (LDH), caspase-3, reactive oxygen species (ROS) generation, eventually leading to induction of apoptosis which was further confirmed through resulting nuclear fragmentation. The present results showed that AgNPs might be a potential alternative agent for human breast cancer therapy.
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