Bioengineered Urethral Augmentation

描述（申请人提供）：尿道功能障碍是糖尿病、脊髓损伤和盆腔创伤的常见并发症。压力性尿失禁（SUI）——由尿道括约肌损伤引起的非自愿尿失禁——在女性中尤为常见，可由阴道分娩引起。目前有几种治疗SUI的方法，但都因无效或随后的并发症而受到限制。包括细胞疗法和组织工程在内的再生医学方法可能会解决这些限制。我们相信使用功能性组织工程尿道包膜（TEUW）将使天然尿道保持完整，同时通过设计再生修复机制提供增强的机械稳定性和功能加固。在这个R21提案中，我们将探索祖细胞作为TEUW的功能成分的使用。具体来说，我们将探讨以下两个假设：i)通过在天然生物基质中适当刺激骨髓衍生祖细胞（BMPCs），可以在体外制造出活的、功能性的、平滑肌填充的管状结构；ii)组织工程尿道包膜（TEUW）可以成功植入，并将逆转在SUI大鼠模型中发现的尿道力学和功能特性的短期变化。我们提出两个具体目标来探索这些假设。目的1：利用BMPCs和适合作为TEUW植入的天然生物基质，制造一个活的、功能性的平滑肌填充管状结构。这将通过确定体外刺激方案来确定，从机械应变和生化物质的组合中选择，产生最佳的组织学，功能，生物力学和免疫学特性。目标2是评估由bmpc衍生的smc填充结构组成的TEUW，这些结构来自特定目标1。评估将包括体外和体内分析，使用组织学、功能、生物力学和免疫学终点。结果将与正常和病变的天然尿道，以及用分离的天然尿道SMCs构建的TEUW进行比较。成功开发一种用于尿道失禁机制不足的TEUW可能会缓解SUI和其他尿道疾病。

DESCRIPTION (provided by applicant): Urethral dysfunction is a common complication of diabetes mellitus, spinal cord injury and pelvic trauma. Stress urinary incontinence (SUI) - the involuntary loss of urine secondary to a damaged urethral sphincter mechanism - is particularly common in women and can result from vaginal childbirth. There are currently several approaches to treat SUI, all of which are limited by ineffectiveness or subsequent complications. Regenerative medicine approaches, including cell therapy and tissue engineering, could potentially address these limitations. We believe that utilization of a functional tissue engineered urethral wrap (TEUW) will allow the native urethra to remain intact, while providing enhanced mechanical stability'and functional reinforcement through designed regenerative repair mechanisms. In this R21 proposal, we will explore the use of progenitor cells as the functional component of a TEUW. Specifically, we will explore the following two hypothesest: i) a living, functional, smooth muscle-populated tubular construct can be fabricated in-vitro by appropriately stimulating bone marrow derived progenitor cells (BMPCs) within a natural biological matrix; and ii) a tissue engineered urethral wrap (TEUW) derived from these constructs can be successfully implanted and will reverse the short-term changes in mechanical and functional properties of the urethra found in a rat model of SUI. We propose two specific aims to explore these hypotheses. AIM 1 is to fabricate a living, functional smooth muscle populated tubular construct from BMPCs and a natural biological matrix that is suitable for implantation as a TEUW. This will be determined by determining the in-vitro stimulation regimen, chosen from combinations of mechanical strain and biochemicals, that yield optimal histological, functional, biomechanical and immunological properties. AIM 2 is to assess a TEUW composed of the BMPC-derived SMC-populated constructs from specific aim 1. Assessments will include both in vitro and in vivo analyses, using histological, functional, biomechanical, and immunological endpoints. Results will be compared with normal and diseased native urethra, as well as a TEUW constructed using isolated native urethral SMCs. Successful development a TEUW for an insufficient urethral continence mechanism would potentially provide relief from SUI and other urethral disorders.