| The urethra is a tubular organ of the end of urinary system, it arises stricture and atresia or missing result from the genetic, trauma, surgical and infection. Long, complicated urethral stricture cause complications such as urine extravasation, urinary fistula, rethral false passage. Even affect other organs of urinary system and cause systemic disease, have a serious impact on the patient’s quality of life. The main treatment measures of urethral stricture including urethral incision, urethral dilation, stent and urethral reconstruction. Urethra end to end anastomosis has better solved the problem of the long urethral stricture that less than 2cm. When the urethral stricture length is more than 2cm, usually have conventional surgical methods, such as narrow segment resection, urethra end to end anastomosis, but can cause the phallocampsis, painful erection. Therefore, it should find new urethra alternative materials for urethra reconstruction(＞2cm).ObjectiveThe lack of tissue repair materials for long urethrostenosis is a thorny problem, tissue engineering materials is one of the ways to solve this problem. Explore the way of noninvasive, convenient, low cost and does not involve the ethical issues to obtain the seed cells will provide a new method for the engineered urethral tissue. The goal of this study was to determine whether urothelial cells (UCs) and smooth muscle cells (SMCs) derived from the differentiation of urine-derived stem cells (USCs) could be used to form engineered urethral tissue when seeded on a modified 3-D porous small intestinal submucosa (SIS) scaffold that to provide a new treatment or urethra alternative materials for urethral reconstruction.MethodsCells were obtained from the urine samples from 6 healthy rabbits (2.0-2.5kg). USCs were isolated, characterized and induced to differentiate into UCs and SMCs. Fresh SIS derived from pigs was decellularized with different concentrations of peracetic acid (PAA) that have comparison of mechanical systems of its tensile strength, the amount of residual cells, growth factor levels and the body’s immune response impact, providing experimental evidence to seek good preparation. Differentiated UCs and SMCs derived from USCs were seeded onto SIS scaffolds with highly porous microstructure in a layered co-culture fashion and cultured under dynamic conditions for 2 weeks. The seeded cells formed multiple uniform layers on the SIS and penetrated deeper into the porous matrix during dynamic culture.ResultsSIS treated with 5% PAA has better porosity and decellularized more thoroughly than that treated with 0% PAA, what’s more, cell penetration and proliferation (5% PAA) was significantly improved than SIS treated with 0% PAA. And the layered co-culture fashion and the dynamic conditions have strengthened the penetration of cells on the SIS and develop a multilayer mucosal structure similar to that of native urinary tract tissue.ConelusionThe layered co-culture fashion and the dynamic conditions have strengthened the penetration of cells on the SIS. USCs that were induced to differentiate into UCs and SMCs, then the dynamic culture system promoted 3-D celle-matrix ingrowth and development of a multilayer mucosal structure similar to that of native urinary tract tissue that can be used as alternative materials for urethral repair or reconstruction. |
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