title: Different behavior of Staphylococcus epidermidis in intracellular biosynthesis of silver and cadmium sulfide nanoparticles: more stability and lower toxicity of extracted nanoparticles.
abstract: Chemical reagents that are used for synthesis of nanoparticles are often toxic, while biological reagents are safer and cost-effective. Here, the behavior of Staphylococcus epidermidis (ATCC 12228) was evaluated for biosynthesis of silver nanoparticles (Ag-NPs) and cadmium sulfide nanoparticles (CdS-NPs) using TEM images intra- and extracellularly. The bacteria only biosynthesized the nanoparticles intracellularly and distributed Ag-NPs throughout the cytoplasm and on outside surface of cell walls, while CdS-NPs only formed in cytoplasm near the cell wall. A new method for purification of the nanoparticles was used. TEM images of pure CdS-NPs confirmed biosynthesis of agglomerated nanoparticles. Biosynthetic Ag-NPs were more stable against bright light and aggregation reaction than synthetic Ag-NPs (prepared chemically) also biosynthetic Ag-NPs displayed lower toxicity in in vitro assays. CdS-NPs indicated no toxicity in in vitro assays. Biosynthetic nanoparticles as product of the detoxification pathway may be safer and more stable for biosensors.
authors.affiliation: Biotechnology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Rezvani Amin
authors.affiliation: Department of Pharmaceutical Control, School of Pharmacy, Mashhad University of Medical Sciences, P.O. Box 91775-1365, Mashhad, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Khashyarmanesh
authors.affiliation: Biotechnology Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. fazlis@mums.ac.ir.|Department of Pharmaceutical Control, School of Pharmacy, Mashhad University of Medical Sciences, P.O. Box 91775-1365, Mashhad, Iran. fazlis@mums.ac.ir.
authors.forename: Bibi Sedigheh
authors.initials: BS
authors.lastname: Fazly Bazzaz
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D019187:Cadmium Compounds / Q000737:chemistry / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002473:Cell Wall / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D006801:Humans; D061986:MCF-7 Cells; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D013212:Staphylococcus epidermidis / Q000502:physiology*; D013440:Sulfides / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D019187:Cadmium Compounds; D013440:Sulfides; C034939:cadmium sulfide; D012834:Silver
keywords: Biosynthesis; Cadmium sulfide nanoparticles; Silver nanoparticles; Staphylococcus epidermidis