title: Fabrication of an optimal urethral graft using collagen-sponge tubes reinforced with Copoly(L-lactide/epsilon-caprolactone) fabric.
abstract: An ideal biomaterial for urethral reconstruction has not been developed. To create a urethral graft biomaterial with optimal biodegradability and biocompatibility, a copoly(L-lactide/epsilon-caprolactone) [P(LA/CL)] fabric tube was combined with a type I collagen sponge. The P(LA/CL) fibers were knitted into a vascular stent style (Type 1) or weaved into a mesh style (Type 2) to prepare P(LA/CL) tubes. The tubes were dipped in aqueous collagen solution and lyophilyzed to prepare the P(LA/CL)-collagen sponge graft. The grafts were applied to a 1.5-cm rabbit urethral defect (n = 14 for each condition), and tissue repair was evaluated using urethrographical, urethroscopical, and histological examination 1, 3, and 6 months after surgery. Although epithelialization was observed after 1 month in all Type 1 grafts, stenoses, fistulae, or stone formation was seen in 7 of the rabbits. In some cases, P(LA/CL) fibers prolapsed into the urethral lumen, causing stone formation. Only 3 rabbits survived for 6 months, and 2 of these had stenoses. For the Type 2 graft, all urethras were patent, without fistulae or stenoses, over the entire observation period. Histologically, urethral structure was disorganized for the Type 1 graft, whereas the urethral tissue on the Type 2 graft was slightly fibrotic but completely epithelialized and supported by a regenerated smooth muscle layer at 6 months. These findings suggest that creation of a scaffold suitable for urethral tissue regeneration will depend not only on the biomaterial composition, but also on the fabrication technique.
authors.affiliation: Department of Urology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Kanatani
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kanematsu
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Inatsugu
authors.forename: Masaaki
authors.initials: M
authors.lastname: Imamura
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Negoro
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Ito
authors.forename: Shingo
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tabata
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Ikada
authors.forename: Osamu
authors.initials: O
authors.lastname: Ogawa
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D003094:Collagen / Q000737:chemistry*; D019544:Equipment Failure Analysis; D006085:Graft Survival / Q000502:physiology*; D008297:Male; D008422:Materials Testing; D011091:Polyesters / Q000737:chemistry*; D019736:Prostheses and Implants; D011474:Prosthesis Design; D011817:Rabbits; D014521:Urethra / Q000473:pathology* / Q000601:surgery*
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; C505727:poly(epsilon-caprolactone-co-lactide); D003094:Collagen