title: Bactericidal application and cytotoxic activity of biosynthesized silver nanoparticles with an extract of the red seaweed Pterocladiella capillacea on the HepG2 cell line.
abstract: BACKGROUND
  Nano-biotechnology is recognized as offering revolutionary changes in various fields of medicine. Biologically synthesized silver nanoparticles have a wide range of applications.
  
  
  METHODS
  Silver nanoparticles (AgNPs) were biosynthesized with an aqueous extract of Pterocladiella (Pterocladia) capillacea, used as a reducing and stabilizing agent, and characterized using UV-VIS spectroscopy, Fourier Transform Infra red (FT-IR) spectroscopy, transmission electron microscopy (TEM) and energy dispersive analysis (EDX). The biosynthesized AgNPs were tested for cytotoxic activity in a human hepatocellular carcinoma (HepG2) cell line cultured in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum, 1% antibiotic and antimycotic solution and 2 mM glutamine. Bacterial susceptibility to AgNPs was assessed with Staphylococcus aureus, Bacillus subtilis [Gram+ve] and Pseudomonas aeruginosa and Escherichia coli [Gram-ve]. The agar well diffusion technique was adopted to evaluate the bactericidal activity of the biosynthesized AgNPs using Ampicillin and Gentamicin as gram+ve and gram-ve antibacterial standard drugs, respectively.
  
  
  RESULTS
  The biosynthesized AgNPs were 11.4±3.52 nm in diameter. FT-IR analysis showed that carbonyl groups from the amino acid residues and proteins could assist in formation and stabilization of AgNPs. The AgNPs showed potent cytotoxic activity against the human hepatocellular carcinoma (HepG2) cell line at higher concentrations. The results also showed that the biosynthesized AgNPs inhibited the entire panel of tested bacteria with a marked specificity towards Bacillus subtillus.
  
  
  CONCLUSIONS
  Cytotoxic activity of the biosynthesized AgNPs may be due to the presence of alkaloids present in the algal extract. Our AgNPs appear more bactericidal against gram-positive bacteria (B. subtillus).
authors.affiliation: Department of Hydrobiology, National Institute of Oceanography and Fisheries, Alexandria, Egypt E-mail : halayassin12@yahoo.com.
authors.forename: Hala Yassin
authors.initials: HY
authors.lastname: El Kassas
authors.forename: Azza Ahmed
authors.initials: AA
authors.lastname: Attia
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects; D006528:Carcinoma, Hepatocellular / Q000188:drug therapy; D045744:Cell Line, Tumor; D004926:Escherichia coli / Q000187:drug effects; D005839:Gentamicins / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy; D053768:Metal Nanoparticles / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D000461:Rhodophyta / Q000378:metabolism*; D012834:Silver / Q000737:chemistry / Q000494:pharmacology*; D012835:Silver Nitrate / Q000737:chemistry / Q000494:pharmacology; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D005839:Gentamicins; D010936:Plant Extracts; D012834:Silver; D000667:Ampicillin; D012835:Silver Nitrate