title: Urethral in situ biocompatibility of new drug-eluting biodegradable stents: an experimental study in the rabbit.
abstract: OBJECTIVE
  To assess the effect of drug-eluting properties on the degradation process and the biocompatibility of biodegradable drug-eluting urethral stents.
  
  
  METHODS
  Braided biodegradable 80 L/20D-PLGA (copolymer of polylactide and polyglycolide) stents with drug-eluting properties were used as the test material. The drugs analysed were indomethacin, dexamethasone and ciprofloxacine. 80 L/20D-PLGA stents without a drug coating served as controls. In all, 16 male rabbits were used and divided into four groups. The stents were inserted under general anaesthesia into the posterior urethra. After 1 month, the rabbits were killed and the urethra removed for histological and optic microscopy analyses.
  
  
  RESULTS
  Control stents and the dexamethasone-eluting stents degraded totally during the follow-up period. Conversely, in both indomethacin- and ciprofloxacine-eluting stent groups, the degradation process was significantly delayed and they induced an increase in epithelial hyperplasia. Histological analysis showed that all the stents induced eosinophilia, but there were no significant differences in the intensity of acute or chronic inflammatory reactions and fibrosis.
  
  
  CONCLUSIONS
  A drug-eluting capacity can be added to biodegradable stents. The addition of a drug influences the biodegradation time of PLGA urethral stents. Further studies are needed, to find the proper concentrations and releasing profiles of the drugs to achieve the desired bioactivity and biocompatibility properties.
authors.affiliation: Department of Urology, Tampere University Hospital, Tampere, Finland. andres.kotsar@uta.fi
authors.forename: Andres
authors.initials: A
authors.lastname: Kotsar
authors.forename: Taina
authors.initials: T
authors.lastname: Isotalo
authors.forename: Ilkka
authors.initials: I
authors.lastname: Uurto
authors.forename: Joonas
authors.initials: J
authors.lastname: Mikkonen
authors.forename: Paula
authors.initials: P
authors.lastname: Martikainen
authors.forename: Martti
authors.initials: M
authors.lastname: Talja
authors.forename: Minna
authors.initials: M
authors.lastname: Kellomäki
authors.forename: Juha-Pekka
authors.initials: JP
authors.lastname: Salenius
authors.forename: Teuvo L J
authors.initials: TL
authors.lastname: Tammela
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D002939:Ciprofloxacin / Q000008:administration & dosage; D003907:Dexamethasone / Q000008:administration & dosage; D054855:Drug-Eluting Stents; D007213:Indomethacin / Q000008:administration & dosage; D019344:Lactic Acid; D008297:Male; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011474:Prosthesis Design; D011817:Rabbits; D014521:Urethra / Q000601:surgery*; D014525:Urethral Stricture / Q000188:drug therapy*
chemical_list: D000890:Anti-Infective Agents; D000893:Anti-Inflammatory Agents; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D002939:Ciprofloxacin; D003907:Dexamethasone; D007213:Indomethacin