title: In situ synthesis and antibacterial activity of copper nanoparticle loaded natural montmorillonite clay based on contact inhibition and ion release.
abstract: Copper nanoparticle based clay composite has been synthesized by in situ reduction of a copper ammonium complex ion and characterized by different analytical instruments. The copper nanoparticles were both intercalated and adsorbed on the surface with diameters of <5nm (for intercalated) and 25-30nm (for adsorbed). The composite showed good stability for over 3 months in air. Excellent antimicrobial activity of the composite was observed on Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis with mortality rates >90% after 12h. Cellular membrane damage permeated by direct attachment of the composite and indirect damage caused by released copper ion are the primary sources of antibacterial action. Cytotoxicity measurements showed minimal adverse effect on the two human cell lines beyond the M.B.C. value for the microorganisms studied. In the present form the clay composite shows good promise for use in therapeutic applications.
authors.affiliation: Physics Department, Jadavpur University, Kolkata 700 032, India.
authors.forename: Biswajoy
authors.initials: B
authors.lastname: Bagchi
authors.forename: Subrata
authors.initials: S
authors.lastname: Kar
authors.forename: Sumit Kr
authors.initials: SK
authors.lastname: Dey
authors.forename: Suman
authors.initials: S
authors.lastname: Bhandary
authors.forename: Debasis
authors.initials: D
authors.lastname: Roy
authors.forename: Tapas Kr
authors.initials: TK
authors.lastname: Mukhopadhyay
authors.forename: Sukhen
authors.initials: S
authors.lastname: Das
authors.forename: Papiya
authors.initials: P
authors.lastname: Nandy
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D001546:Bentonite / Q000737:chemistry*; D002413:Cations, Divalent; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003260:Contact Inhibition / Q000187:drug effects; D003300:Copper / Q000737:chemistry*; D013293:Enterococcus faecalis / Q000187:drug effects / Q000254:growth & development; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008826:Microbial Sensitivity Tests; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D017550:Spectroscopy, Fourier Transform Infrared; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D002413:Cations, Divalent; D001546:Bentonite; D003300:Copper