Larsson HM Vythilingam G Pinnagoda K Vardar E Engelhardt EM Sothilingam S Thambidorai RC Kamarul T Hubbell JA Frey P 2018 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. application/pdf https://sonar.ch/global/documents/69766 eng info:eu-repo/semantics/altIdentifier/doi/10.1038/s41598-018-27621-9 info:eu-repo/semantics/altIdentifier/pmid/29968749 info:eu-repo/semantics/openAccess Scientific reports. - 2018 Animals Collagen Dietary Fiber Extracellular Matrix Male Models, Animal Muscle, Smooth Rabbits Reconstructive Surgical Procedures Regeneration Tissue Engineering Transplants Urethra Fiber density of collagen grafts impacts rabbit urethral regeneration. http://purl.org/coar/resource_type/c_6501