Urethral in situ biocompatibility of new drug-eluting biodegradable stents: an experimental study in the rabbit.
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.
Kotsar
Andres
A
Department of Urology, Tampere University Hospital, Tampere, Finland. andres.kotsar@uta.fi
Isotalo
Taina
T
Uurto
Ilkka
I
Mikkonen
Joonas
J
Martikainen
Paula
P
Talja
Martti
M
Kellomäki
Minna
M
Salenius
Juha-Pekka
JP
Tammela
Teuvo L J
TL
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*
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