PDF Publication Title:
Text from PDF Page: 010
Theranostics 2020, Vol. 10, Issue 20 biosynthesis of AgNPs with various sizes and shapes [59] (Table 4). These extracts from different plant parts contain organic components such as enzymes, alcohols, flavonoids, alkaloids, quinines, oils, terpenoids and phenolic compounds [126, 127]. There are different functional groups in these organic components [58], like hydroxyl, carbonyl, amidogen, which may contribute to the reduction of Ag+ to Ag0. A variety of plant extracts, including the components mentioned above and plant derivatives such as starch, cellulose, chitin, dextran and alginates, act simultaneously as reducing agents and stabilizers [128]. The plant-mediated synthesis of AgNPs is influenced by different reaction parameters such as temperature, reaction time, pH and concentration of plant extracts and precursors [129, 130]. The AgNPs with different size and shape can be obtained by changing the synthesis parameters [129]. In summary, plant-mediated synthesis of AgNPs can be controlled by a variety of reaction conditions. In addition, different parts of plant exhibit various abilities in the synthesis of AgNPs [131]. The mechanisms of plant-mediated synthesis of AgNPs need more exploration. In conclusion, the plant-mediated synthesis of AgNPs using plant extract is a promising method due to its easy availability , nontoxicity , simplicity, cost-effectiveness and high reducing potential. Medical Applications of AgNPs Antimicrobial and anticancer properties of AgNPs have been widely studied. Studies have shown that AgNPs have broad-spectrum antimicrobial properties against pathogens including bacteria, fungi and viruses [19, 49]. Besides, AgNPs can effectively damage or kill nematodes [152] and worms [153]. A variety of factors affect the antimicrobial activities of AgNPs, including size, shape, dose and stabilizer of AgNPs [49, 154, 155]. Interestingly, AgNPs may have different antibacterial effects against Gram-positive and Gram-negative bacteria [156]. AgNPs exhibit broad-spectrum anticancer properties. Anticancer activity of AgNPs is also affected by a variety of factors, including size, shape, dose, and exposure time [22, 157, 158]. It is also realized that the surface charge of AgNPs is a potential factor. Although current specific mechanisms of antimicrobial and anticancer properties of AgNPs are still unclear, many studies have carried out hypothesis. AgNPs can inhibit the growth of bacteria or kill them by inducing membrane destruction, ROS generation, DNA damage, enzyme inactivation and protein denaturation [4, 56, 159]. However, the anticancer mechanisms of AgNPs are much more complicated. Until now, it has been 9005 approved that AgNPs can inhibit the growth of tumor cells by destroying the cellular ultrastructures, inducing ROS production and DNA damage [21-23, 160]. In addition, AgNPs can induce tumor cell apoptosis through inactivating proteins and regulating signaling pathways, or blocking tumor cell metastasis by inhibiting angiogenesis within lesion [31, 161]. Besides antimicrobial and anticancer properties, AgNPs can also be used in other medical applications, such as bone repair [162] and wounding repair [163]. And AgNPs can be regarded as an additive in dental materials or an adjuvant in vaccine. In this part, we will discuss the antimicrobial and anticancer properties and possible mechanisms of AgNPs, as well as other promising medical applications. Antimicrobial Application of AgNPs Antibacterial Properties of AgNPs AgNPs have been proven to effectively inhibit various pathogenic bacteria, fungi and viruses, including Staphylococcus aureus [164], Escherichia coli [165], Pseudomonas aeruginosa [166], dermatophyte [167], HIV-1, etc. [168, 169]. The antibacterial effect of AgNPs against various strains of bacteria is different [156]. Rather than Gram-positive bacteria, AgNPs show a stronger effect on the Gram-negative ones. This may be due to the different thickness of cell wall between two kinds of bacteria [170]. Besides the bacteria strains, AgNPs may also exhibit size-, shape-, concentration-, time-, and charge-dependent antibacterial activity. In general, as particle size decreases, the antibacterial effect of AgNPs increases significantly [171]. Especially when the size is less than 10 nm, AgNPs show better antibacterial activity [172]. The antibacterial effect can be significantly enhanced by prolonging the treatment time of AgNPs [173]. The increased bacterial mortality may be ascribed to the accumulation of AgNPs and silver ions during the exposure period. Besides, the shape of AgNPs may also influence the antibacterial activity [171, 174]. By comparing the antibacterial activity of spherical, triangular, linear and cubic AgNPs, it is observed that spherical shaped AgNPs exhibit superior antibacterial effect. This phenomenon suggests that AgNPs with larger surface to volume ratio, which relates to both higher effective contact and larger reaction surface, may show stronger antibacterial activity [174]. In addition, the antimicrobial activity of AgNPs is also affected by the surface charge [156, 175]. Due to the presence of lipopolysaccharide, peptidoglycan and multiple groups, including carboxyl, amino and phosphate groups, bacterial membranes are primarily loaded with negative charges [170, 176]. Positive charge can http://www.thno.orgPDF Image | Silver nanoparticles Synthesis medical applications safety
PDF Search Title:
Silver nanoparticles Synthesis medical applications safetyOriginal File Name Searched:
thnov10p8996.pdfDIY PDF Search: Google It | Yahoo | Bing
Turbine and System Plans CAD CAM: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. More Info
Waste Heat Power Technology: Organic Rankine Cycle uses waste heat to make electricity, shaft horsepower and cooling. More Info
All Turbine and System Products: Infinity Turbine ORD systems, turbine generator sets, build plans and more to use your waste heat from 30C to 100C. More Info
CO2 Phase Change Demonstrator: CO2 goes supercritical at 30 C. This is a experimental platform which you can use to demonstrate phase change with low heat. Includes integration area for small CO2 turbine, static generator, and more. This can also be used for a GTL Gas to Liquids experimental platform. More Info
Introducing the Infinity Turbine Products Infinity Turbine develops and builds systems for making power from waste heat. It also is working on innovative strategies for storing, making, and deploying energy. More Info
Need Strategy? Use our Consulting and analyst services Infinity Turbine LLC is pleased to announce its consulting and analyst services. We have worked in the renewable energy industry as a researcher, developing sales and markets, along with may inventions and innovations. More Info
Made in USA with Global Energy Millennial Web Engine These pages were made with the Global Energy Web PDF Engine using Filemaker (Claris) software.
Infinity Turbine Developing Spinning Disc Reactor SDR or Spinning Disc Reactors reduce processing time for liquid production of Silver Nanoparticles.
| CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com | RSS | AMP |