复合RGD肽修饰胶原支架的骨髓间充质干细胞移植促进严重子宫损伤功能性修复的实验研究

There is lack of effective treatment to severe uterine damages which is the main cause of uterine factor infertility. Tissue engineering may offer a new method for uterine functional reparation after severe damages. In our previous studies, collagen scaffolds loaded with collagen binding bFGF were used in the reparation of new trauma of rat uterine horns after full thickness injury. The results showed better pregnancy outcomes. For the uterine scar tissue reparation, additional growth factors were needed, which suggeting that collagen scaffolds with single slow releaseed growth factors were not sufficient to fully recover the functional reparation of uterine after severe injury. Bone marrow derived mesenchymal stem cells (BMSCs) have been shown to enhance functional wound healing by releasing paracrine factors which could promote rapid cell regeneration and vascularization in numerous studies. Since the uterus is a hollow muscular organ, scaffolds were needed to provide support for BMSCs to adhere to endometrial wound. Arginine-glycine-aspartate (Arg(R)-Gly(G)-Asp(D), RGD) peptides modification can enhance the cell adhesion ability of collagen scaffold. Thus we speculate that RGD peptides immobilized collagen scaffold loaded with BMSCs may be more beneficial for maintaining BMSCs in local trauma to play a role in wound healing. In the current study, we evaluate the effectiveness of RGD peptides immobilized collagen scaffolds for the biological activity of BMSCs and the reparation of rat uterine horns after severe damages, and reveal the paracrine function of BMSCs during the reparation process, which may offer a elementary evidence for the clinical treatment of severe uterine damages.

严重子宫内膜损伤是子宫性不孕的常见原因，目前缺乏有效治疗方法。组织工程为此类损伤的功能性修复提供了新思路。我们前期利用胶原支架结合bFGF修复大鼠子宫全层新鲜损伤，得到良好的妊娠结果，但对于陈旧性子宫疤痕则需要另外的生长因子，提示支架缓释单一生长因子不足以使严重子宫损伤功能性修复。骨髓间充质干细胞（BMSCs）能够分泌多种细胞因子，在损伤的功能性修复中能促进创面快速细胞化、血管化。由于子宫是肌性空腔器官，需要支架为BMSCs粘附到创面提供支撑，研究表明精氨酸-甘氨酸-天冬氨酸肽(RGD肽)修饰能够增强胶原支架细胞粘附能力。我们推测RGD肽修饰胶原支架复合BMSCs更有利于维持BMSCs在创面局部发挥作用。本项目拟探索RGD肽修饰胶原支架的方法、其对BMSCs生物学活性影响及修复子宫严重损伤的效果；评估BMSCs旁分泌功能在促进子宫损伤修复中的作用，为临床治疗提供依据。

严重子宫内膜损伤是子宫性不孕的常见原因，目前缺乏有效治疗方法，组织工程为此类损伤的功能性修复提供了新思路。项目建立大鼠子宫新鲜损伤模型，利用胶原支架复合MSCs进行损伤修复，研究发现MSCs能够粘附于胶原支架上并增殖迁移至支架内部，MRI扫描发现术后MSCs主要定位于损伤修复区域。MSCs通过旁分泌功能分泌bFGF、VEGF等细胞因子促进损伤区域细胞增殖、血管再生及平滑肌修复，并能促进损伤区域子宫妊娠功能恢复。同时项目建立大鼠子宫损伤后陈旧性疤痕愈合模型，利用凝胶状可降解胶原纤维复合MSCs进行陈旧性疤痕修复，研究结果提示其通过上调MMP-9加速疤痕组织中胶原降解，促进细胞增殖及血管生成，从而促进疤痕组织修复。综上所述，胶原支架复合MSCs能够促进大鼠子宫损伤修复，为其临床上治疗严重子宫损伤提供理论依据。