【摘要】 目的:探索以骨髓间充质干细胞为种子细胞构建组织工程化海绵体尿道的可行性。方法:实验于2004-11/2006-03在中山大学第二附属医院医学科研中心完成。①参照张金明等报道的方法,制备脱细胞尿道海绵体-尿道基质,并行组织学检查观察脱细胞效果。②分离兔骨髓间充质干细胞,鉴定其表型,体外培养增殖后种植于兔脱细胞尿道海绵体-尿道基质上。③48只兔随机均分为实验组、对照组,每组24只。实验组用种植有干细胞的脱细胞基质即组织工程尿道修复部分切除的兔海绵体尿道,对照组组仅用脱细胞基质修复。④术后观察动物排尿情况,并于术后1,2,4,8,12,24周切取标本,看有无狭窄及腔面一般性状并行组织学检查,比较两者差异。结果:两组共48只兔全部进入结果分析。①自行制备的组织工程支架和种子细胞鉴定结果:所制备脱细胞基质质地柔软,镜下未见细胞成份;分离培养的细胞表型为CD45阴性,CD166,CD29,CD105阳性,符合骨髓间充质干细胞特征。②术后动物及标本一般观察:实验组术后2周时发现1例尿瘘;对照组2周时发现1例尿瘘,8,12,24周时分别发现各1例尿道狭窄。其余实验动物在拔除导尿管后排尿通畅。③两组兔再造尿道组织学检查结果:实验组自术后2周开始,组织学检查见血管和平滑肌逐渐增多;24周时,尿道腔面光滑,可见和正常尿道海绵体类似的组织结构。对照组自2周起可见血管,4周起可见平滑肌再生,24周时血管和平滑肌形成仍较少,较多纤维瘢痕,且无窦样组织形成,再造尿道腔面不如实验组光滑。结论:以骨髓间充质干细胞为种子细胞,脱细胞尿道海绵体为基质,构建组织工程化尿道海绵体,移植修复兔海绵体尿道缺损,可形成类似于正常尿道海绵体的组织结构。更多还原

【Abstract】 AIM: To investigate the feasibility to construct cavernous urethra with bone marrow mesenchymal stem cells (MSCs). METHODS: The experiment was conducted in the research center of Second Hospital affiliated to Sun Yat-sen University from November 2004 to March 2006. ①Acellular spongy body of urethra-urethral matrix was prepared according to the methods reported by Zhang and the acellular effect was observed by 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. ③Forty-eight rabbits were randomly divided into experiment group and control group with 24 animals in each group. The tissue-engineered urethra with stem cells was implanted into the cavernous urethra after partial resection of the experiment group, while the control group was only given acellular matrix. ④The urination of animals was observed after operation. The rabbits were sampled at 1, 2, 4, 8, 12 and 24 week after operation to detect if there was stenosis and cavosurface general traits. The histological examination was performed and the results of two groups were compared. RESULTS: All 48 rabbits were involved in the result analysis. ①Identification of prepared scaffold and seed cells: The acellular matrix had good elasticity and mechanical properties, and no cells were observed. Phenotype of the isolated cells was CD45 negative, CD166, CD29 and CD105 positive, which were in accordance with the characteristics of MSCs. ②General observation of postoperative animals and samples: One urinary fistula was observed in the experiment group at 2 week after operation, and one fistula (at 2 week) and 3 urinary stenosis (at 8, 12, 24 weeks) were observed in the control group. Other samples of two groups maintained unobstructed urination after removing the urethral catheter. ③Histological examination of reconstructed urethra: Two weeks after operation, epithelial cells and small vessels were observed in the experiment group. At the 24th week, the urethral cavosurface was found smooth, and the tissues similar to normal spongy body of urethra were observed. In the control group, the vessels were observed since the second week, and smooth muscle regeneration at the fourth week, but still few at the 24th week with many fiber scars; the reconstructed urethral cavosurface was not the smooth as the experiment group. CONCLUSION: Tissue-engineered cavernous urethra, which is constructed with MSCs as the seed cells and acellular spongy body of urethra as the matrix, could repair the urethral defects, and form the tissues similar to normal corpus cavernous urethra.更多还原