Development of novel bioabsorbable synthetic grafts for ureteral regeneration

我们以前曾报道过，通过手术用由聚-（丙交酯/己内酯）共聚物和胶原组成的生物可吸收合成管移植物替代，已成功地再生了有缺陷的尿道（Kanatani，et. Al.：Tissue Engineering 13：2933，2007）。在此基础上，制备了同种材料的尿道再生管。然而，由于兔输尿管的直径细小，置换术在技术上存在一定的困难。接下来，我们假设只要从外部用合适的材料包裹，就可以修复尿道。在这一点上，我们专注于平滑肌和细胞外基质的行为。为了简化我们的实验设计，大鼠膀胱壁被释放bFGF的明胶片覆盖。结果，bFGF促进膀胱平滑肌增殖和基质重塑，这增强了整体膀胱收缩性（Imamura等人：Imamura等人Al.：美国生理学杂志。Renal Physiology 293：F1007，2007）。最后，用bFGF缓释明胶片包裹大鼠输尿管。两周后观察到尿道壁肥大伴毛细血管新生。有必要阐明这种现象是否有助于输尿管的功能性再生。

We have previously reported that the deficient urethras had been successfully regenerated by surgically replacing with the bioabsorbable synthetic tube grafts composed of poly-(lactide/ -caprolactone) copolymer and collagen (Kanatani, et. Al.: Tissue Engineering 13: 2933,2007). Based on these techniques and results, the tube grafts composed of the identical materials were prepared for urethral regeneration. However, unfortunately, the replacement of the rabbit ureter was technically difficult due to the fine diameters of those.Next, we hypothesized that the urinary tract can be repaired by simply wrapping from outside with appropriate materials. At this point, we focused on the behavior of smooth muscle and extracellular matrix. To simplify our experimental design, the rat bladder wall was covered by a gelatin sheet releasing bFGF. As a result, bFGF promoted the bladder smooth muscle proliferation and matrix remodeling, which reinforced the overall bladder contractility (Imamura et.al.:Imamura, et. Al.: American Journal of Physiology. Renal Physiology 293:F1007,2007).Finally, the rat ureter was wrapped with a bFGF sustained-release geratin sheet. Two weeks later urethral wall hypertrophy associated with a capillary angiogenesis was observed. There will be a need to elucidate whether this phenomenon contributes to functional regeneration of the ureter.