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./nMethods: 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./nResults: 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)./nConclusion: 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.

中文翻译：

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使用移植在预血管化胶囊上的自体平滑肌细胞片进行膀胱重建。

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。测试了使用组织扩张器胶囊作为诱导血管床在兔模型中预制功能性血管化平滑肌组织皮瓣用于膀胱重建的功效。将皮肤组织扩张剂插入腹股沟以诱导血管化囊袋的形成。收获平滑肌细胞和内皮祖细胞并共培养以形成预先血管化的平滑肌细胞片。然后每两天间隔将三层细胞片移植物重复移植到血管化的荚膜组织上，以预制功能性血管化的平滑肌组织皮瓣。膀胱肌壁缺损是由六层细胞片移植物（仅片），囊状皮瓣（仅胶囊）和预先涂有平滑肌细胞片的血管化胶囊（片加胶囊）产生并修复的。植入后对动物进行3个月的随访，并连续植入其膀胱。在整个3个月中，片加胶囊组的膀胱容量和顺应性维持。组织浴刺激表明，三组对卡巴胆碱和氯化钾的收缩反应显示出显着差异（p < 0.05）。组织学上，仅胶囊组在1个月时发炎，而仅片状组在3个月时观察到纤维化。在每个时间点，仅胶囊组和片加胶囊组的血管密度均显着高于仅片组（p < 0.05）。三组中平滑肌含量的比较显示出显着差异（p < 0.05）。/n结论：这些结果证明该胶囊可以用作血管化的平滑肌组织皮瓣预制的诱导血管床。预制的功能化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。