Fabrication of an optimal urethral graft using collagen-sponge tubes reinforced with Copoly(L-lactide/epsilon-caprolactone) fabric

Tissue Eng. 2007 Dec;13(12):2933-40. doi: 10.1089/ten.2007.0052.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry*
  • Collagen / chemistry*
  • Equipment Failure Analysis
  • Graft Survival / physiology*
  • Male
  • Materials Testing
  • Polyesters / chemistry*
  • Prostheses and Implants*
  • Prosthesis Design
  • Rabbits
  • Urethra / pathology*
  • Urethra / surgery*

Substances

  • Biocompatible Materials
  • Polyesters
  • poly(epsilon-caprolactone-co-lactide)
  • Collagen