胎儿脐静脉脱细胞基质构建组织工程尿道

目的 探讨人脐静脉细胞外基质的制备及其在尿道重建中的应用.方法 采用酶消化、去污剂和渗透溶液方法制备人脐静脉细胞外基质(extracellular matrix,ECM).24只雄性白兔,随机分为A尿道ECM移植组,对照组B、C.A组切除尿道2.0 cm后用人脐静脉ECM修复,术后行组织学、尿流动力学和膀胱尿道造影评价尿道再生情况及功能.结果 经该法处理的人脐静脉细胞全部脱除.A组修复术后2周,脐静脉ECM有单层上皮细胞生长;4周管腔已被上皮细胞完全覆盖;8周可见人脐静脉ECM降解的微小碎片和平滑肌细胞生长,炎性细胞消失;16周尿道大体观、组织学检查均接近C组,平滑肌数量与C组差异无统计学意义(P>0.05),但排列欠规则.膀胱尿道造影无尿液外渗、尿道憩室形成;尿动力学A组与C组膀胱容量、最大尿道压分别与术前比较,差异均无统计学意义(P>0.05),B组无法置入测压管.结论 酶消化、去污剂和渗透溶液法是制备人脐静脉ECM较为理想的方法,人脐静脉ECM可作为尿道重建的良好支架材料.

Experimental study on urethral reconstruction with extracellular matrix of human umbillical vein

Objective To assess the feasibility of using extracellular matrix (ECM) of human umbilical veins in reconstruction of urethral defect.Methods Extracellular matrix of human umbilical veins was prepared using hypotonic,hypertonic solutions,detergent and proteinase in a multistep process.Twenty-four male rabbits were divided randomly into three groups,including experimental group A,control group B and C.In group A(n=12),,the 2.0cm urethral defect was repaired with extracellular matrix of human umbilical vein graft.The regeneration of urethra was assessed with histology,urodynamic study and retrograde urethrography post-operatively.Results Morphological analyses showed that the cells were removed effectively from umbilical veins and the elastic and collagen fibers were.Two weeks post-operatively,,epithelial cells migrated from each side into the ECM.Minimal infihration of inflammatory cells was also observed at the host-matrix anastomosis;however,these cells disappeared 8 weeks postoperatively.The epithelium covered the DCM fully 4 weeks postoperatively.At 8th post-operative week,minimal extracellular matrix of Human umbilical veins graft was observed in the host tissue.New smooth-muscle cells were confirmed.Sixteen weeks postopera-tively,the histology of group A is similar to that of the group C,and there was no difference in the number of the urethral smooth muscles between the tWO groups.But the smooth muscles of group A were obviously disorganized comparing with those of group C The urehrography and urodynarnic evalnation revealed that there was no difference between the group A and the group C Conclusions Extracellular matrix of human umbilieal veins is potentially a good candidate material for urethral reconstruction.