负载BMSCs及bFGF-壳聚糖纳米微粒的改良聚丙烯盆底重建网片的实验研究

At present, the preferred treatment method for female pelvic floor dysfunction, including stress urinary incontinence (SUI) and pelvic organ prolapse (POP), is pelvic floor reconstruction with polypropylene mesh. However there are adverse side effects of this method, such as vaginal mesh exposure, postoperative recurrence after midurethral sling placement and mesh erosion,, even loading mesh with silver nanofiber or polylactic acid. Growing evidences reveal that decreased collagen concentration and collagen fiber in muscle and connective tissue of pelvic floor are observed in women with female pelvic floor dysfunction.Fortunately elastin-expression bone marrow-derived mesenchymal stem cells (BMSCs) can be differentiated to fibroblasts by basic fibroblast growth factor (bFGF),finally promoting the repair and regeneration of damage tissues..Our previous research has confirmed that the polypropylene mesh researched and developed by our group meets the claim of China’s State Food and Drug Administration. Meanwhile mesenchymal stem cells have been isolated and chitosan nanoparticles encapsulated growth factors also have been prepared. So in the present study we plan to reduce the risk of mesh exposure after pelvic floor reconstruction, failure of surgery and other adverse reactions through improving polypropylene mesh porosity and loading mesh with nanoparticles in which elastin-expressing BMSCs and bFGF are formulated.

聚丙烯盆底重建术是盆腔脏器脱垂（POP）和压力性尿失禁（SUI）的手术治疗的常用方法，但该方法存在网片暴露等不良反应。近年来国内外尝试通过复合纳米银、聚乳酸等方法改进PP网片，但研究显示仍有诸多不良反应。研究表明POP及SUI患者的肌肉及结缔组织中弹性蛋白含量下降，碱性成纤维细胞生长因子(bFGF)可诱导弹性蛋白高表达骨髓间充质干细胞(BMSCs)分化成成纤维细胞，并上调弹性蛋白表达，加速组织修复、降低手术并发症。.本课题组前期已研发达到国家食品药品监督管理总局医疗植入材料标准的PP网片，且成功制备可包裹bFGF的壳聚糖纳米颗粒。本研究拟在前期研究的基础上，通过改良PP网片降低网片暴露；通过包裹bFGF纳米颗粒涂层的PP网片加速结缔组织生成；通过弹性蛋白基因转导入BMSCs，上调重建区域弹性蛋白表达，加速创面修复。上述方法综合运用可降低盆底重建术后网片暴露等不良反应、减少二次手术风险。

盆腔器官脱垂（POP）是中老年女性常见病，盆底聚丙烯网片植入手术是有效的治疗方式，但降低POP术后网片的不良反应及并发症是亟需解决的研究问题。本研究前期研究工作的基础上，进行了聚丙烯网片的改良，成功制备了负载BMSCs的bFGF-壳聚糖聚醚酰亚胺纳米微粒-聚丙烯网片，首先，本课题组制备了性能与结构近似于进口网片的国产化网片，通过添加含有促进BMSCs 向成纤维细胞分化的bFGF-壳聚糖聚醚酰亚胺纳米微粒，以纳米材料为桥梁，将高表达弹性蛋白的BMSCs/bFGF 共同附着在聚丙烯网片上。并成功建立了大鼠及犬的盆底脱垂动物模型，通过手术将网片植入至缺损薄弱处，结果表明，相较于聚丙烯网片组（PPM组），负载BMSCs的bFGF-壳聚糖聚醚酰亚胺纳米微粒-聚丙烯网片组的炎症细胞浸润程度显著好于PPM材料；可有效促进胶原再生，其中III/I型胶原比例显著提高；可以诱导肌成纤维细胞和血管再生；还可利用BMSCs的免疫调节作用进而对微环境中巨噬细胞进行免疫调控，促进其向促进修复的M2型转化，促进盆底修复、缩短修复时间，减少并发症发生。该网片可降低盆底重建术后的网片相关的不良反应、减少二次手术风险，同时研究方法和研究结果为研发低暴露率的新型网片提供借鉴参考和理论依据。