A collaboration between researchers from the Bernal Institute, Royal College of Surgeons in Ireland and University of Pittsburgh will enable the fabrication of a biomimetic urethral scaffold that mimics the mechanics, composition and structure of the native tissue.
The human urethra is a complex tubular organ that allows urine to drain from the urinary bladder. Trauma to the urethra is a frequent and costly event that can be caused by injury, inflammation, stricture, congenital defect or malignancy. Urethra repair strategies often use a skin flap or vascularised graft. Grafts that are formed from a patient’s own tissue are difficult to harvest, have limited availability and are associated with donor site morbidity. Tissue engineered urethral scaffolds are not subject to such limitations.
However, existing urethral scaffolds frequently fail as they do not mimic the composition, structure or mechanical properties of the native tissue, which were previously unknown. This study therefore addresses a crucial gap in the literature by characterising the relationship between urethral tissue mechanics, composition and gross structure.
The study involved using pressure-diameter and uniaxial extension testing to characterise urethra tissue mechanics. The composition and structure of the tissue was determined using immunohistological staining. The findings were then used to develop a biomimetic urethral scaffold with physical properties that more accurately mimic the native tissue than existing tissue engineered scaffolds.
The tissue characterisation data presented in this study paves the way for the development of biomimetic urethral grafts and demonstrates positive findings that warrant further in vivo evaluation.
This work was funded by the European Union’s Horizon 2020 research and innovation program under a Marie Sklodowska-Curie grant awarded to Dr Eoghan Cunnane. The human tissue was supplied by Professor Jochen Hess (University Hospital Essen), tissue characterisation was performed in the Bernal Bio labs under the supervision of Professor Michael Walsh, scaffold fabrication was performed in collaboration with Professor Fergal O’Brien (Royal College of Surgeons in Ireland) and animal work was performed in collaboration with Professor David Vorp (University of Pittsburgh).
The study is published in the journal Biomaterials:
Mechanical, compositional and morphological characterisation of the human male urethra for the development of a biomimetic tissue engineered urethral scaffold.