title: Cell-based detection of microbial biomaterial contaminations.
abstract: A major challenge in biomaterial synthesis and functionalization is the prevention of microbial contaminations such as endotoxins (lipopolysaccharides (LPS)). In addition to LPS, which are exclusively expressed by Gram negative bacteria, also other microbial products derived from fungi or Gram positive bacteria can be found as contaminations in research laboratories. Typically, the Limulus amebocyte lysate (LAL)-test is used to determine the endotoxin levels of medical devices. However, this test fails to detect material-bound LPS and other microbial contaminations and, as demonstrated in this study, detects LPS from various bacterial species with different sensitivities.In this work, a cell-based assay using genetically engineered RAW macrophages, which detect not only soluble but also material-bound microbial contaminations is introduced.The sensitivity of this cell-line towards different LPS species and different heat-inactivated microbes was investigated. As proof of principle a soft hydrophobic poly(n-butyl acrylate) network (cPnBA), which may due to adhesive properties strongly bind microbes, was deliberately contaminated with heat-inactivated bacteria. While the LAL-test failed to detect the microbial contamination, the cell-based assay clearly detected material-bound microbial contaminations. Our data demonstrate that a cell-based detection system should routinely be used as supplement to the LAL-test to determine microbial contaminations of biomaterials.
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Helmholtz-Zentrum Geesthacht, Teltow, Germany.|Helmholtz Virtual Institute - Multifunctional Biomaterials for Medicine, Teltow and Berlin, Germany.
authors.forename: Toralf
authors.initials: T
authors.lastname: Roch
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Helmholtz-Zentrum Geesthacht, Teltow, Germany.|Helmholtz Virtual Institute - Multifunctional Biomaterials for Medicine, Teltow and Berlin, Germany.|Department of Biology, Institute of Chemistry and Biochemistry, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany.
authors.forename: Nan
authors.initials: N
authors.lastname: Ma
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Helmholtz-Zentrum Geesthacht, Teltow, Germany.|Helmholtz Virtual Institute - Multifunctional Biomaterials for Medicine, Teltow and Berlin, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Kratz
authors.affiliation: Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies (BCRT), Helmholtz-Zentrum Geesthacht, Teltow, Germany.|Helmholtz Virtual Institute - Multifunctional Biomaterials for Medicine, Teltow and Berlin, Germany.|Department of Biology, Institute of Chemistry and Biochemistry, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany.|Institute of Chemistry, University of Potsdam, Potsdam, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lendlein
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis*; D001431:Bacteriological Techniques; D001672:Biocompatible Materials; D001681:Biological Assay; D002460:Cell Line; D004866:Equipment Contamination / Q000517:prevention & control; D004864:Equipment and Supplies / Q000382:microbiology*; D008033:Limulus Test; D008264:Macrophages / Q000502:physiology*; D008422:Materials Testing; D051379:Mice
chemical_list: D001427:Bacterial Toxins; D001672:Biocompatible Materials
keywords: Biomaterials; endotoxins; immuno-compatibility; microbial contaminations; polymers