title: In vitro evaluation of novel antimicrobial coatings for surgical sutures using octenidine.
abstract: BACKGROUND
  Sutures colonized by bacteria represent a challenge in surgery due to their potential to cause surgical site infections. In order to reduce these type of infections antimicrobially coated surgical sutures are currently under development. In this study, we investigated the antimicrobial drug octenidine as a coating agent for surgical sutures. To achieve high antimicrobial efficacy and required biocompatibility for medical devices, we focused on optimizing octenidine coatings based on fatty acids. For this purpose, antimicrobial sutures were prepared with either octenidine-laurate or octenidine-palmitate at 11, 22, and 33 μg/cm drug concentration normalized per length of sutures. Octenidine containing sutures were compared to the commercial triclosan-coated suture Vicryl® Plus. The release of octenidine into aqueous solution was analyzed and long-term antimicrobial efficacy was assessed via agar diffusion tests using Staphylococcus aureus. For determining biocompatibility, cytotoxicity assays (WST-1) were performed using L-929 mouse fibroblasts.
  
  
  RESULTS
  In a 7 days elution experiment, octenidine-palmitate coated sutures demonstrated much slower drug release (11 μg/cm: 7%; 22 μg/cm: 5%; 33 μg/cm: 33%) than octenidine-laurate sutures (11 μg/cm: 82%; 22 μg/cm: 88%; 33 μg/cm: 87%). Furthermore sutures at 11 μg/cm drug content were associated with acceptable cytotoxicity according to ISO 10993-5 standard and showed, similar to Vicryl® Plus, relevant efficacy to inhibit surrounding bacterial growth for up to 9 days.
  
  
  CONCLUSIONS
  Octenidine coated sutures with a concentration of 11 μg/cm revealed high antimicrobial efficacy and biocompatibility. Due to their delayed release, palmitate carriers should be preferred. Such coatings are candidates for clinical testing in regard to their safety and efficacy.
authors.affiliation: Klinikum rechts der Isar, Technische Universität München, Klinik für Orthopädie und Sportorthopädie, Ismaninger Str. 22, 81675, Munich, Germany. aobermeier@tum.de.
authors.forename: A
authors.initials: A
authors.lastname: Obermeier
authors.affiliation: Klinikum rechts der Isar, Technische Universität München, Institut für Mikrobiologie, Immunologie und Hygiene, Trogerstr. 30, 81675, Munich, Germany. jochen.schneider@tum.de.
authors.forename: J
authors.initials: J
authors.lastname: Schneider
authors.affiliation: Klinikum rechts der Isar, Technische Universität München, Klinik für Orthopädie und Sportorthopädie, Ismaninger Str. 22, 81675, Munich, Germany. foehr@tum.de.
authors.forename: P
authors.initials: P
authors.lastname: Föhr
authors.affiliation: Klinikum rechts der Isar, Technische Universität München, Klinik für Orthopädie und Sportorthopädie, Ismaninger Str. 22, 81675, Munich, Germany. steffen.wehner@mytum.de.
authors.forename: S
authors.initials: S
authors.lastname: Wehner
authors.affiliation: Universitätsklinik für Orthopädie und Orthopädische Chirurgie, Medizinische Universität, Auenbruggerplatz 5, 8036, Graz, Austria. Klaus.kuehn@medunigraz.at.
authors.forename: K-D
authors.initials: KD
authors.lastname: Kühn
authors.affiliation: Klinikum rechts der Isar, Technische Universität München, Klinik für Orthopädie und Sportorthopädie, Ismaninger Str. 22, 81675, Munich, Germany. axel.stemberger@lrz.tum.de.
authors.forename: A
authors.initials: A
authors.lastname: Stemberger
authors.affiliation: Klinikum der Universität München, Klinik für Chirurgie, Experimentelle Chirurgie und Regenerative Medizin, Nußbaumstr. 20, 80336, Munich, Germany. matthias.schieker@med.uni-muenchen.de.
authors.forename: M
authors.initials: M
authors.lastname: Schieker
authors.affiliation: Klinikum rechts der Isar, Technische Universität München, Klinik für Orthopädie und Sportorthopädie, Ismaninger Str. 22, 81675, Munich, Germany. burgkart@tum.de.
authors.forename: R
authors.initials: R
authors.lastname: Burgkart
mesh_terms: D000818:Animals; D000891:Anti-Infective Agents, Local / Q000378:metabolism* / Q000633:toxicity; D002470:Cell Survival / Q000187:drug effects; D005227:Fatty Acids / Q000378:metabolism* / Q000633:toxicity; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007097:Imines; D051379:Mice; D008826:Microbial Sensitivity Tests; D011725:Pyridines / Q000378:metabolism* / Q000633:toxicity; D013211:Staphylococcus aureus / Q000187:drug effects*; D013537:Sutures
chemical_list: D000891:Anti-Infective Agents, Local; D005227:Fatty Acids; D007097:Imines; D011725:Pyridines; C034213:octenidine