title: Purified and sterilized magnetosomes from Magnetospirillum gryphiswaldense MSR-1 were not toxic to mouse fibroblasts in vitro.
abstract: OBJECTIVE
  To establish a criterion for measuring the purity of purified and sterilized magnetosomes from Magnetospirillum gryphiswaldense and to evaluate their toxicity for mouse fibroblasts in vitro.
  
  
  RESULTS
  The purification of magnetosomes involves disrupting bacterial cells with a French Press, washing directly with PBS buffer accompanied by treatment with low power ultrasonication, and using a magnet to collect the magnetosomes. Five characteristic peaks were displayed by Fourier-transform infrared spectroscopy (FT-IR), which was used to detect the quality of the purified magnetosomes, at 3273, 2921, 1735, 1645 and 1531 cm(-1). The purified magnetosomes showed no evidence of impurities when observed by transmission electron microscopy and energy disperse spectroscopy. The particles could be stored at -20 degrees C after lyophilization and treatment by gamma-rays. Purified and sterilized magnetosomes had no obvious negative effects on the viability of mouse fibroblasts by 3-(4,5-dimethylthiazolyl)-2,5-diphenyl-tetrazolium bromide assay.
  
  
  CONCLUSIONS
  Purified and sterilized magnetosomes were not toxic to mouse fibroblasts in vitro.
  
  
  CONCLUSIONS
  This study provides methods for evaluating the purity and safety of magnetosomes from M. gryphiswaldense. The magnetosomes have the potential to be used as novel drug or gene carriers for tumour therapy.
authors.affiliation: Key Laboratory of Agro-Microbial Resources and Application, Ministry of Agriculture, College of Biological Sciences, China Agricultural University, Beijing, China.
authors.forename: L
authors.initials: L
authors.lastname: Xiang
authors.forename: J
authors.initials: J
authors.lastname: Wei
authors.forename: S
authors.initials: S
authors.lastname: Jianbo
authors.forename: W
authors.initials: W
authors.lastname: Guili
authors.forename: G
authors.initials: G
authors.lastname: Feng
authors.forename: L
authors.initials: L
authors.lastname: Ying
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003594:Cytoplasmic Granules; D005347:Fibroblasts; D008280:Magnetics; D042201:Magnetospirillum / Q000254:growth & development / Q000648:ultrastructure*; D051379:Mice; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000633:toxicity; D017550:Spectroscopy, Fourier Transform Infrared; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism
chemical_list: D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue