PDF(Sci-hub)
Abstract：
Rationale: Construction of functional vascularized three-dimensional tissues has been a longstanding objective in the field of tissue engineering. The efficacy of using a tissue expander capsule as an induced vascular bed to prefabricate functional vascularized smooth muscle tissue flaps for bladder reconstruction in a rabbit model was tested. Methods: Skin tissue expanders were inserted into the groin to induce vascularized capsule pouch formation. Smooth muscle cells and endothelial progenitor cells were harvested and cocultured to form pre-vascularized smooth muscle cell sheet. Then repeated transplantation of triple-layer cell sheet grafts onto the vascularized capsular tissue was performed at 2-day intervals to prefabricate functional vascularized smooth muscle tissue flaps. Bladder muscular wall defects were created and repaired by six-layer cell sheet graft (sheet only), capsule flap (capsule only) and vascularized capsule prelaminated with smooth muscle cell sheet (sheet plus capsule). The animals were followed for 3 months after implantation and their bladders were explanted serially. Results: Bladder capacity and compliance were maintained in sheet plus capsule group throughout the 3 months. Tissue bath stimulation demonstrated that contractile responses to carbachol and KCl among the three groups revealed a significant difference (p < 0.05). Histologically, inflammation was evident in the capsule only group at 1 month and fibrosis was observed in sheet only group at 3 months. The vessel density in capsule only and sheet plus capsule group were significantly higher than in the sheet only group at each time point (p < 0.05). Comparison of the smooth muscle content among the three groups revealed a significant difference (p < 0.05). Conclusion: These results proved that the capsule may serve as an induced vascular bed for vascularized smooth muscle tissue flap prefabrication. The prefabricated functional vascularized smooth muscle tissue flap has the potential for reliable bladder reconstruction and may create new opportunities for vascularization in 3-D tissue engineering.
摘要：
原理：功能性血管化三维组织的构建一直是组织工程领域的长期目标。测试了在兔模型中使用组织扩张器囊作为诱导血管床预制功能性血管化平滑肌组织瓣进行膀胱重建的功效。方法：将皮肤组织扩张器插入腹股沟以诱导血管化囊囊袋形成。收获平滑肌细胞和内皮祖细胞并共培养以形成预血管化的平滑肌细胞片。然后每隔2天将三层细胞片移植物重复移植到血管化的囊状组织上，以预制功能性血管化的平滑肌组织瓣。创建膀胱肌壁缺损并通过六层细胞片移植物（仅薄片）修复，囊皮瓣（仅胶囊）和血管化胶囊预层压平滑肌细胞片（薄片加胶囊）。植入后对动物进行3个月的随访，并连续移植其膀胱。结果：在整个3个月中，片状胶囊组的膀胱容量和依从性均保持不变。组织浴刺激表明，三组之间对卡巴胆碱和KCl的收缩反应表现出显着差异（p<0.05）。组织学上,1个月时，仅胶囊组出现明显的炎症，3个月时，仅胶囊组出现纤维化。在每个时间点，仅胶囊和片状胶囊组的血管密度均显着高于仅片状胶囊组（p<0.05）。三组间平滑肌含量的比较显示有显著差异(p<0.05)。结论：这些结果证明，胶囊可作为血管化平滑肌组织皮瓣预制的诱导血管床。预制的功能性血管化平滑肌组织瓣具有可靠的膀胱重建潜力，并可能为3-D组织工程中的血管化创造新的机会。
