ABSTRACT

Cartilage tissue engineering is a promising option for repairing cartilage defects, although harvesting a large number of seeding cells remains a major challenge. Cartilage stem/progenitor cells (CSPCs) seem to be a promising cell source. Hypoxic extracellular vesicles (EVs) may play a major role in cell-cell and tissue-tissue communication. In the current study, we aimed to evaluate the effect of hypoxic adipose-derived stem cells (ADSCs)-derived EVs on CSPCs proliferation and differentiation. The characteristics of ADSCs-derived EVs were identified, and proliferation, migration, and cartilage-related gene expression of CSPCs were measured with or without the presence of hypoxic ADSCs-derived EVs. SEM, histological staining, biochemical and biomechanical analysis was performed to evaluate the effect of hypoxic ADSCs-derived EVs on CSPCs in alginate hydrogel culture. The results indicated that the majority of ADSC-derived EVs exhibited a round-shaped or cup-shaped morphology with a diameter of 40–1000 nm and expressed CD9, CD63, and CD81. CSPCs migration and proliferation were enhanced by hypoxic ADSCs-derived EVs, which also increased the expression of cartilage-related genes. The hypoxic ADSCs-derived EVs induce CSPCs to produce significantly more cartilage matrix and proteoglycan. In conclusion, hypoxic ADSCs-derived EVs improved the proliferation and chondrogenic differentiation of CSPCs for cartilage tissue engineering.

 抽象的

软骨组织工程是修复软骨缺陷的一种有前途的选择，尽管收获大量的种子细胞仍然是一个主要挑战。软骨干/祖细胞（CSPC）似乎是一种有前途的细胞来源。缺氧的细胞外囊泡（EV）可能在细胞间和组织间通讯中发挥重要作用。在当前的研究中，我们旨在评估低氧脂肪干细胞（ADSC）衍生的EV对CSPC增殖和分化的影响。鉴定了 ADSC 衍生的 EV 的特征，并在存在或不存在缺氧 ADSC 衍生的 EV 的情况下测量 CSPC 的增殖、迁移和软骨相关基因表达。通过扫描电镜、组织学染色、生化和生物力学分析来评估缺氧 ADSC 衍生的 EV 对藻酸盐水凝胶培养物中 CSPC 的影响。结果表明，大多数 ADSC 衍生的 EV 呈圆形或杯形形态，直径为 40-1000 nm，表达 CD9、CD63 和 CD81。缺氧的 ADSC 衍生的 EV 增强了 CSPC 的迁移和增殖，这也增加了软骨相关基因的表达。缺氧的 ADSC 衍生的 EV 诱导 CSPC 产生显着更多的软骨基质和蛋白多糖。总之，缺氧 ADSC 衍生的 EV 改善了软骨组织工程中 CSPC 的增殖和软骨分化。