ESPU Congress 2018 - Abstract Book

40 29 th CONGRESS OF THE ESPU 15:50–15:53 S3-6 (PP) GEL CASTING AS AN APPROACH FOR TISSUE ENGINEERING OF MULTILAYERED TUBULAR STRUCTURES: APPLICATION FOR URETHRAL RECONSTRUCTION Melissa VAN VELTHOVEN  1 , Rana RAMADAN  1 , Barbara KLOTZ  2 , Debby GAWLITTA  2 , Miguel CASTILHO  3 , Jos MALDA  3 , Pedro COSTA  3 , Laetitia DE KORT  1 and Petra DE GRAAF  1 1) UMC Utrecht, Urology, Utrecht, NETHERLANDS - 2) UMC Utrecht, Oral and Maxillofacial Surgery, Utrecht, NETHERLANDS - 3) UMC Utrecht, Orthopedics, Utrecht, NETHERLANDS PURPOSE There is a lack of tissue-engineered solutions for replacement of urological tissues. Bottle necks are vascularization and the complex tubular organization with different cell layers. As the corpus spongiosum (CS) is an integral and functional part of the urethra, tissue engineering of the urethra should be combined with the CS. The CS is a multilayered, highly vascularized structure with distinct distribution of extracellular matrix components. Here we propose an innovative gel casting approach to engineer three-layered tubular constructs. MATERIAL AND METHODS A mold with three chambers was designed and fabricated. The chambers were loaded with gelatin- based hydrogels containing endothelial cells and pericytes (chamber 1 and 3 to form the inner and outer layer) and smooth muscle cells (chamber 2 to form the middle layer). A fiber mesh was placed at the base of the construct to serve as support for the gels and to roll the gel into a multilayered tubular construct. Hydrogels were mechanically tested and compared to native tissue. RESULTS The gel could be casted and rolled into a multilayered construct. The encapsulated cells formed little capillary-like structures (chamber 1 and 3) and produced elastin (chamber 2) within two weeks. The compressive modulus of the gel was comparable to native tissue. CONCLUSIONS Our approach enables to engineer tubular constructs with distinct compositions in the different layers. Cell survival and functionality up to two weeks has been achieved and the biomechanical properties were similar to native tissue. This approach towards tissue engineering of multilayered tubular structures may be applicable to the urological field as well as other fields of soft tissue engineering.