转基因脂肪干细胞分类诱导后复合异种尿道海绵体脱细胞基质修复长管状尿道缺损的体外研究

长段管状尿道缺损等复杂尿道损伤（>3cm）的传统治疗手段损伤大且并发症较多，组织工程化尿道的制备目前存在操作繁琐、创伤较大、无法兼顾功能恢复等难题。本研究通过取材皮下脂肪，制备具有多向分化潜能的脂肪干细胞，通过转基因技术，利用慢病毒载体将抗菌肽LL37这一具有光谱抗微生物活性和促内皮、血管新生的活性肽物质转染入脂肪干细胞内，再通过体外诱导分别得到组织工程尿道最为关键的两种种子细胞——转基因上皮样细胞和平滑肌样细胞。为改善术后尿道支撑并促进细胞的黏附增殖，我们选取异种尿道海绵体脱细胞基质作为支架材料，通过高速震荡+静态接种的技术分别将种子细胞种植到支架材料上，构建新型组织工程化尿道，提高尿道替代材料的上皮化、血管化及支撑能力，使复杂性尿道缺损达到真正意义上的生物学修复。

The therapeutic effect of complex urethral problems are unsatisfactory, especially for the treatment of long and tubular urethral defects more than 3cm. There are many drawbacks in traditional tissue engineering about complex urethral defects, such as complicated operations, lithogenesis, avascular necrosis, erectile dysfunction, etc. Adipose derived stem cells (ADSCs) can be obtained from subcutaneous fatty tissue, and have ability of multipotential differentiation. We plan to culture ADSCs transfected by antibiotic peptide LL37 which have multiple antibacterial activities and angiogenesis through lentiviral vectors. Then we will induce the transfected ADSCs to differentiate into epithelioid cells and smooth muscle cells. The new-style engineered urethras will be constructed with heterogenous acellular urethral sponge matrix and the above two cells. And we aim to assess the effectiveness of engineered urethras in dogs suffering long and tubular urethral defects more than 3cm.