Fiber density of collagen grafts impacts rabbit urethral regeneration

• Main Authors: Larsson, H.M., Vythilingam, G., Pinnagoda, K., Vardar, E., Engelhardt, E.M., Sothilingam, S., Thambidorai, R.C., Kamarul, Tunku, Hubbell, J.A., Frey, P.
• Format: Article
• Language: English
• Published: Nature Publishing Group 2018
• Subjects: R Medicine; T Technology (General); TA Engineering (General). Civil engineering (General)
• Online Access: http://eprints.um.edu.my/18977/1/Fiber_density_of_collagen_grafts_impacts_rabbit_urethral_regeneration.pdf; http://eprints.um.edu.my/18977/; http://dx.doi.org/10.1038/s41598-018-27621-9

There is a need for efficient and "off-The-shelf" grafts in urethral reconstructive surgery. Currently available surgical techniques require harvesting of grafts from autologous sites, with increased risk of surgical complications and added patient discomfort. Therefore, a cost-effective and cell-free graft with adequate regenerative potential has a great chance to be translated into clinical practice. Tubular cell-free collagen grafts were prepared by varying the collagen density and fiber distribution, thereby creating a polarized low fiber density collagen graft (LD-graft). A uniform, high fiber density collagen graft (HD-graft) was engineered as a control. These two grafts were implanted to bridge a 2 cm long iatrogenic urethral defect in a rabbit model. Histology revealed that rabbits implanted with the LD-graft had a better smooth muscle regeneration compared to the HD-graft. The overall functional outcome assessed by contrast voiding cystourethrography showed patency of the urethra in 90% for the LD-graft and in 66.6% for the HD-graft. Functional regeneration of the rabbit implanted with the LD-graft could further be demonstrated by successful mating, resulting in healthy offspring. In conclusion, cell-free low-density polarized collagen grafts show better urethral regeneration than high-density collagen grafts.