01714nas a2200205   4500008004100000022001400041245005700055210005600112260011000168300001400278490000700292520099100299100001801290700002501308700001901333700001701352700001901369700003001388856009001418       2008                        eng d  a0959-942800aBacterial synthesis of silicon/silica nanocomposites0 aBacterial synthesis of siliconsilica nanocomposites  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAPR  a2601-26060 v183 a<p>The synthesis of silicon/silica nanoparticle composites by the bacterium Actinobacter sp. is demonstrated. More specifically, the formation of silicon/silica nanocomposite is shown to occur when the bacterium is exposed to K(2)SiF(6) precursor under ambient conditions. Based on the earlier reports where this bacterium has been shown to synthesize iron oxide and iron sulfide nanoparticles, it is hypothesized that this bacterium secretes reductases and oxidising enzymes, which lead to the Si/SiO(2) nanocomposite synthesis. The particles obtained by bacterial synthesis were thoroughly characterized. The cytotoxicity studies revealed that the particles do not display any cytotoxicity to human skin cells. The synthesis of silica nanoparticles by bacteria in the present study demonstrates the versatility of the organism, and the formation of elemental silicon by this environmentally friendly process expands further the scope of microorganism based nanomaterial synthesis.</p>1 aSingh, Sanjay1 aBhatta, Umananda, M.1 aSatyam, P., V.1 aDhawan, Alok1 aSastry, Murali1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/bacterial-synthesis-siliconsilica-nanocomposites-001819nas a2200253   4500008004100000245009700041210006900138260000800207300001000215490000600225520098700231653001701218653001701235653001801252653001701270653001901287100001801306700002501324700002101349700001901370700001701389700003001406856012901436       2010                        eng d00aBacterial synthesis of phtocatalytically active and biocompatible TiO2 and ZnO nanoparticles0 aBacterial synthesis of phtocatalytically active and biocompatibl  cDEC  a80-990 v23 a<p>TiO2 and ZnO nanoparticles are well known for their photocatalytic and ultraviolet (UV)-absorbent properties and have successfully entered into the market as consumer products. Large volume production of these nanoparticles by industries require environmentally friendly processes of synthesis. In this article, we show that when challenged with an appropriate precursor, the bacterium Actinobacter spp. can lead to the extracellular synthesis of ZnO and TiO2 nanoparticles. The biological way of synthesizing these materials probably leads to the in situ doping of elements like C, F, and N into their crystal lattices, which is evidenced by a red shift in the absorption edge. Because the doping is expected to affect the photocatalytic activity of these materials under different light conditions, such investigations have also been undertaken here. Further, the biocompatibility of these nanomaterials (cytotoxicity and genotoxicity) has also been investigated in detail.</p>10aBiosynthesis10agenotoxicity10aNanoparticles10aNanotoxicity10aPhotocatalysis1 aSingh, Sanjay1 aBritto, Virginia, D.1 aBharde, Atul, A.1 aSastry, Murali1 aDhawan, Alok1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/bacterial-synthesis-phtocatalytically-active-and-biocompatible-tio2-and-zno-nanoparticles01597nas a2200205   4500008004100000022001400041245010300055210006900158260011000227300001200337490000700349520078500356100001801141700002301159700002101182700001901203700001701222700003001239856012201269       2010                        eng d  a1144-054600aCytotoxic and genotoxic assessment of glycolipid-reduced and -capped gold and silver nanoparticles0 aCytotoxic and genotoxic assessment of glycolipidreduced and capp  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcNOV  a294-3010 v343 a<p>A systematic cytotoxic and genotoxic evaluation of glycolipid-conjugated silver and gold nanoparticles is carried out. These glycolipid nanoparticle conjugates are obtained by exploiting the reductive capability of a class of glycolipids called sophorolipids that play the role of capping agent as well. Further, when tested for their cytotoxicity and genotoxicity on HepG2 cells, these nanoparticles are found to be cytocompatible up to 100 mu M metal concentrations. Of the two metallic systems investigated, gold nanoparticles are found to be more cytocompatible than the same concentrations of silver nanoparticles. Similarly, it is also demonstrated that at 100 mu M, silver nanoparticles cause more DNA damage compared to gold nanoparticles of similar concentrations.</p>1 aSingh, Sanjay1 aD'Britto, Virginia1 aPrabhune, Asmita1 aRamana, C., V.1 aDhawan, Alok1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/cytotoxic-and-genotoxic-assessment-glycolipid-reduced-and-capped-gold-and-silver-0