ABSTRACT

Articular cartilage has limited self-regenerative capacity and the therapeutic methods for cartilage defects are still dissatisfactory in clinic. Recent studies showed that exosomes derived from mesenchymal stem cells promoted chondrogenesis by delivering bioactive substances to the recipient cells, indicating exosomes might be a novel method for repairing cartilage defect. Herein, we investigated the role and mechanism of human umbilical cord mesenchymal stem cells derived small extracellular vesicles (hUC-MSCs-sEVs) on cartilage regeneration. In vitro results showed that hUC-MSCs-sEVs promoted the migration, proliferation and differentiation of chondrocytes and human bone marrow mesenchymal stem cells (hBMSCs). MiRNA microarray showed that miR-23a-3p was the most highly expressed among the various miRNAs contained in hUC-MSCs-sEVs. Our data revealed that hUC-MSCs-sEVs promoted cartilage regeneration by transferring miR-23a-3p to suppress the level of PTEN and elevate expression of AKT. Moreover, we fabricated Gelatin methacrylate (Gelma)/nanoclay hydrogel (Gel-nano) for sustained release of sEVs, which was biocompatible and exhibited excellent mechanical property. In vivo results showed that hUC-MSCs-sEVs containing Gelma/nanoclay hydrogel (Gel-nano-sEVs) effectively promoted cartilage regeneration. These results indicated that Gel-nano-sEVs have a promising capacity to stimulate chondrogenesis and heal cartilage defects, and also provided valuable data for understanding the role and mechanism of hUC-MSCs-sEVs in cartilage regeneration.

摘要

关节软骨的自我再生能力有限，软骨缺损的治疗方法在临床上仍不令人满意。最近的研究表明，来自间充质干细胞的外泌体通过向受体细胞传递生物活性物质来促进软骨形成，这表明外泌体可能是修复软骨缺损的一种新方法。在这里，我们调查了人类脐带间充质干细胞衍生的小细胞外囊泡（hUC-MSCs-sEVs）在软骨再生中的作用和机制。体外结果表明，hUC-MSCs-sEVs促进了软骨细胞和人骨髓间充质干细胞（hBMSCs）的迁移，增殖和分化。MiRNA芯片显示，在hUC-MSCs-sEV中包含的各种miRNA中，miR-23a-3p的表达最高。我们的数据表明，hUC-MSCs-sEVs通过转移miR-23a-3p抑制PTEN的水平并提高AKT的表达来促进软骨再生。此外，我们制造了甲基丙烯酸明胶（Gelma）/纳米粘土水凝胶（Gel-nano）以持续释放sEV，具有生物相容性并表现出优异的机械性能。体内结果表明，包含Gelma / nanoclay水凝胶（gel-nano-sEVs）的hUC-MSCs-sEVs可以有效促进软骨再生。这些结果表明，Gel-nano-sEVs具有刺激软骨生成和修复软骨缺损的潜力，并且为理解hUC-MSCs-sEVs在软骨再生中的作用和机理提供了有价值的数据。