University Lecturer, Universiti Sains Malaysia
Economically biosynthesized AgNPs for anticancer therapeutic purposes
Nanomedicine can be defined as the medical application of nanotechnology and it is an interdisciplinary field that involves biology, chemistry, physics, medicine, material science, and biomedical engineering. Due to their size with approximately 1 to 100 nm, nanomaterials have greater potential to travel inside living organisms than other materials or larger particles, making them an alternative in therapeutic approaches and disease diagnostics that cannot be accomplished by conventional strategies. Although nanomaterials are expected to have a significant impact on medicine, however they still need to overcome several challenges before they are widely used. Therefore, understanding the interaction of nanomaterials in the context of cellular environment is crucial for the success of nanomaterials. Inorganic nanomaterials such as gold, silver, iron, titanium, copper, silica, and zinc oxide have been fabricated as nanoparticles for several pharmaceutical applications, including cancer therapeutics. Conventional radiotherapies based on x-ray and gamma–ray radiations are the most widespread techniques in the world for the treatment of malignant diseases due to its ability to penetrate tissues and thus allowing it to reach the deeply sited sites. The only limitation of radiotherapy is the lack of selectivity between the tumor and the healthy surrounding tissues. Interestingly, previous studies have shown that AgNPs have the ability to selectively induce cytotoxic effects on cancer cells, as compared to normal cells. This serves another advantage of using nanomaterials, allowing them to selectively induce cytotoxic effects on cancer cells. Production of metal nanoparticles can be achieved through different methods such as chemical and biological methods. However, these methods involve the use of toxic and hazardous chemicals such as sodium borohydride, potassium bitartrate, methoxypolyethylene glycol and hydrazine which will potentially give negative impact on human health. Currently, nanoparticles of metal noble are particular interest because of their broad range of application in many areas such as drug delivery system, cancer diagnosis and therapy. AgNPs become an increasing demand in the market due to a lot of its application in medical area. As chemically-synthesised AgNPs were reported to be toxic to human health, bio-synthesised AgNPS from plant extract could be the other option, for instance plant, fungi and bacteria.
Abstract: Metal nanoparticles have largely been investigated due to their potential medicinal activities. This study demonstrates the biological properties of green-synthesized silver nanoparticles (AgNPs) by using Artemisia tournefortiana Rchb ethanol extract. Instrumentations such as ultraviolet-visible spectra analysis, high-resolution transmission electron microscopy, scanning electron microscopy, energy-dispersive X-ray analysis, X-ray diffraction, and Fourier transform infrared spectroscopy were used to reveal the synthesized AgNPs. Microscopic results showed that the particles were mostly spherical in shape, having an average diameter of 22.89±14.82nm. The antibacterial activity of the phyto-fabricated AgNPs was investigated by the determination of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The in vitro cytotoxicity effect was investigated against normal human embryonic kidney (HEK293) cells and human colon adenocarcinoma cancer (HT29) cells. The apoptotic cells were identified by annexin V/PI FITC staining, and morphological assessment. The expressions of Bax and Bcl2 were evaluated by quantitative real time PCR method. The phyto-synthesized AgNPs have shown increased cell apoptosis and demonstrated dose-dependent cytotoxicity in HT29 cancer cells. Moreover, the photocatalytic activity of the phyto-synthesized AgNPs was evaluated by degradation of Coomassie Brilliant Blue G-250 under UV light exposure and these fabricated Ag nanoparticles demonstrated efficacy in degrading the dye within 60min. Overall, the present results highlighted the antibacterial and anticancer properties of fabricated AgNPs, suggesting that phyto-synthesized silver nanoparticles could possess potent anti-pathogenic bacteria and anti-colon cancer activities.
Pub.: 16 Jul '17, Pinned: 04 Oct '17
Abstract: In the present study, silver nanoparticles (PJB-AgNPs) have been biosynthesized employing Prosopis juliflora bark extract. The biosynthesis of silver nanoparticles was monitored on UV-vis spectrophotometer. The size, charge and polydispersity index (PDI) of PJB-AgNPs were determined using dynamic light scattering (DLS). Different parameters dictating the size of PJB-AgNPs were explored. Nanoparticles biosynthesis optimization studies suggested efficient synthesis of highly dispersed PJB-AgNPs at 25 °C when 9.5 ml of 1 mM AgNO3 was reduced with 0.5 ml of bark extract for 40 min. Characterization of PJB-AgNPs by SEM showed spherical-shaped nanoparticles with a size range ∼10-50 nm along with a hydrodynamic diameter of ∼55 nm as evaluated by DLS. Further, characterizations were done by FTIR and EDS to evaluate the functional groups and purity of PJB-AgNPs. The antibacterial potential of PJB-AgNPs was tested against E. coli and P. aeruginosa. The PJB-AgNPs remarkably exhibited anticancer activity against A549 cell line as evidenced by Alamar blue assay. The dye degradation activity was also evaluated against 4-nitrophenol that has carcinogenic effect. The results thus obtained suggest application of PJB-AgNPs as antimicrobial, anticancer and catalytic agents.
Pub.: 20 Jul '17, Pinned: 04 Oct '17
Abstract: Gemcitabine (GEM) is widely used as an anticancer agent in several types of solid tumors. Silver nanoparticles (AgNPs) possess unique cytotoxic features and can induce apoptosis in a variety of cancer cells. In this study, we investigated whether the combination of GEM and AgNPs can exert synergistic cytotoxic effects in the human ovarian cancer cell line A2780.We synthesized AgNPs using resveratrol as a reducing and stabilizing agent. The synthesized nanomaterials were characterized using various analytical techniques. The anticancer effects of a combined treatment with GEM and AgNPs were evaluated using a series of cellular assays. The expression of pro- and antiapoptotic genes was measured using real-time reverse transcription polymerase chain reaction. Apoptosis was confirmed by TUNEL assay.In this study, combined treatment with GEM and AgNPs significantly inhibited viability and proliferation in A2780 cells. Moreover, the levels of apoptosis in cells treated with a combination of GEM and AgNPs were significantly higher compared with those in cells treated with GEM or AgNPs alone. Our data suggest that GEM and AgNPs exhibit potent apoptotic activity in human ovarian cancer cells. Combined treatment with GEM and AgNPs showed a significantly higher cytotoxic effect in ovarian cancer cells compared with that induced by either of these agents alone.Our study demonstrated that the interaction between GEM and AgNPs was cytotoxic in ovarian cancer cells. Combined treatment with GEM and AgNPs caused increased cytotoxicity and apoptosis in A2780 cells. This treatment may have therapeutic potential as targeted therapy for the treatment of ovarian cancer. To our knowledge, this study could provide evidence that AgNPs can enhance responsiveness to GEM in ovarian cancer cells and that AgNPs can potentially be used as chemosensitizing agents in ovarian cancer therapy.
Pub.: 19 Sep '17, Pinned: 04 Oct '17
Abstract: Silver is a non-essential element, with promising antimicrobial and anticancer properties. This work is a detailed summary of the newest findings on the bioinorganic chemistry of silver, with a special focus on the applications of Ag+ complexes and nanoparticles. The coordination chemistry of silver is given a reasonable amount of attention, summarizing the most common silver binding sites and giving examples of such binding motifs in biologically important proteins. Possible applications of this metal and its complexes in medicine, in particular as antibacterial and antifungal agents and in cancer therapy is discussed in detail. The most recent data on silver nanoparticles are also summarized.
Pub.: 22 Sep '17, Pinned: 04 Oct '17