| BackgroundGenito-urinary system, congenital malformations, acquired injury or due to other diseases caused by defects or urethral stricture surgery is urologist efforts to explore one of the themes,however, the lack of alternative materials urethra has been the biggest problem plagued urologist.The rise of tissue engineering for the repair and reconstruction of the genitourinary system has opened up a new path.In recent years, many scholars in the urinary tract tissue engineering has made remarkable achievements.Acellular matrix of small intestinal mucosa, bladder mucosa acellular matrix, acellular human umbilical vein matrix, acellular human amniotic membrane matrix, etc, have been used for urethral reconstruction studies, and achieved some results, and fully explain the use of acellular tissue matrix has its possible re-urethralsex.Acellular tissue matrix used in the theoretical basis for tissue repair in the removal of cellular components with the antigen at the same time, be able to retain their natural extracellular matrix, and biological characteristics, so that it can basically achieve the in vivo immunogenicity of the state of non.In the urinary system, the study of tissue engineering materials, frame materials have an important role.Acellular matrix as an ideal scaffold material more and more attention.In 1999 SCIENCE stem cell research as the top ten results of scientific research of the first year, and in 2000, the year of its re-named the world's top ten scientific achievements.This shows that people have been foreseen stem cells in medicine and life sciences huge potential and bright prospects.Stem cells are undifferentiated cells in a class of its powerful ability to self-renewal and can be divided to form the final maturity of non-renewable cells and effector cells.Of the biggest advantages of such cells, in accordance with a certain degree of differentiation of its channels directed differentiation to form the same material with the existing organization, because these characteristics of their field of organ transplantation in the organization has great application prospect.As people on the stem cell-based medicine and clinical research continued to deepen, apply stem cells to repair tissues and organs of regenerative medicine (regenerative medicine) are gradually becoming a reality.At home and abroad have not seen the rabbit bone marrow mesenchymal stem cells as seed cells, porcine acellular urethral matrix for tissue engineering scaffold material of rabbit urethra repaired urethral defect reported in the literature.ObjectivesTo evaluate the feasibility to construct corpus cavernous urethra with rabbit bone marrow mesenchymal stem cells (MSCs).Methods①Acellular spongy body of urethra-urethral matrix was prepared and the acellular effect was observedby histological examination.②MSCs were harvested, and their phenotype was identified. The cells were cultured on to the acellular spongy body of urethra-urethral matrix after amplification.③Sixty rabbits were randomly divided into experimental group and control group equally. The tissue-engineered urethra with stem cells was implanted into the cavernous urethra after rabbits partial resection of about 2cm length in the experimental group, while the control group was only given acellular matrix.④Two groups of grafted speciments were cut after operation, then evaluated histologically and compared the differences.⑤At 24 weeks postoperation, one group was underwent retrograde urethrography and the other was evaluated in urodynamics, then compared the differences.Results①The acellular matrix had good elasticity and mechanical properties, and no cells were observed. Phenotype of the isolated cells was CD45 negative, CD166, CD29, CD 105 positive, which were in accordance with the characteristics of MSCs.②The results of histological examination of reconstructed urethra at 24 weeks: the urethral cavosurface was found smooth, and the tissues similar to normal spongy body of urethra were observed in the experimental group. In the control group, the regeneration of vessels and smooth muscle was less and many fiber scars, the reconstructed urethral cavosurface was not the smooth as the experimental group.③In the experimental group, compared the maximum urethra pressure before and after urodynamics operation, there was no significant difference.(p>0.05), while in the control group, there was significant difference.(p<0.05).Conclusions1.Tissue-engineered cavemous urethra, which is constructed with MSCs as the seed cells and acellular spongy body of the urethra as the matrix, could repair the urethral effects, and form the tissues similar to normal corpus cavernous urethra.2.Rabbit bone marrow mesenchymal stem cells as seed cells, acellular pig urethra as a substrate to construct tissue-engineered urethra, the relatively abundant sources of material, operation simple, less traumatic, is a good, worthy of further study, with clinical applicationprospects for urethral reconstruction of alternative materials.
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