Cheng Qi, Guo Qianping, Zhang Xiaoyu, Zhu Yuanchen, Liu Chengyuan, Wang Huan, Zhu Caihong, Ni Li, Li Bin, Yang Huilin
Department of Orthopaedic Surgery, Orthopaedic Institute, The First Affiliated Hospital, Suzhou Medical College, Soochow University, Suzhou, Jiangsu, 215006, China.
Orthopaedic Department, Xuzhou Central Hospital, No. 199, The Jiefang South Road, Xuzhou, 221009, Jiangsu, China.
Mater Today Bio. 2025 Feb 14;31:101569. doi: 10.1016/j.mtbio.2025.101569. eCollection 2025 Apr.
The self-repair ability of articular cartilage is limited, which is one of the most difficult diseases to treat clinically. Kartogenin (KGN) induces chondrogenesis by regulating RUNX1 mRNA translation and the small molecule compound TD-198946 (TD) promotes chondrogenic differentiation of mesenchymal stem cells (MSCs) through increasing the transcription of RUNX1 mRNA. GelMA hydrogel and liposomes are respectively similar to the extracellular matrix (ECM) and extracellular vesicles (EVs). So, we developed an "EVs-in-ECM" mimicking system by incorporating GelMA and KGN/TD-loaded liposomes to investigate the repair effects of cartilage defect. First, western-blot, RNA fluorescence in situ hybridization (FISH), cellular immuno-fluorescence, co-immuno-precipitation (CO-IP), and qRT-PCR techniques showed that KGN regulated RUNX1 mRNA expression, and then promote chondrogenic differentiation of MSCs. Second, the role of RUNX1 was amplified by orchestrating RUNX1 transcription and translation through TD-198946 (TD) and KGN respectively, and the synergistic effects of TD and KGN on chondrogenesis of MSCs in vitro were discovered. Finally, an "EVs-in-ECM" mimicking system was designed for in situ cartilage repair. When GelMA loaded with KGN and TD liposomes, the hydrogel (KGN + TD@ GelMA) showed biological functions by the continuously controlled release of KGN and TD while maintaining its porous structure and mechanical strength, which enhanced the chondrogenesis of MSCs in one system. The repair performance of "EVs-in-ECM" in vivo was assessed using the articular osteochondral defect model of rat. The implantation of KGN + TD@ GelMA hydrogels effectively exerted favorable osteochondral repair effects showing structures similar to the native tissue, and prevented chondrocyte hypertrophy. The study indicate that the "EVs-in-ECM" mimicking system can act as a highly efficient and potent scaffold for osteochondral defect regeneration.
关节软骨的自我修复能力有限，这是临床上最难治疗的疾病之一。Kartogenin（KGN）通过调节RUNX1 mRNA的翻译诱导软骨形成，小分子化合物TD - 198946（TD）通过增加RUNX1 mRNA的转录促进间充质干细胞（MSC）的软骨分化。甲基丙烯酰化明胶水凝胶（GelMA）和脂质体分别类似于细胞外基质（ECM）和细胞外囊泡（EVs）。因此，我们通过将GelMA与负载KGN/TD的脂质体结合，开发了一种“ECM中的EVs”模拟系统，以研究软骨缺损的修复效果。首先，蛋白质免疫印迹、RNA荧光原位杂交（FISH）、细胞免疫荧光、免疫共沉淀（CO - IP）和qRT - PCR技术表明，KGN调节RUNX1 mRNA表达，进而促进MSC的软骨分化。其次，分别通过TD - 198946（TD）和KGN协调RUNX1的转录和翻译来放大RUNX1的作用，并发现TD和KGN在体外对MSC软骨形成的协同作用。最后，设计了一种“ECM中的EVs”模拟系统用于原位软骨修复。当GelMA负载KGN和TD脂质体时，水凝胶（KGN + TD@GelMA）通过持续可控地释放KGN和TD发挥生物学功能，同时保持其多孔结构和机械强度，这在一个系统中增强了MSC的软骨形成。使用大鼠关节骨软骨缺损模型评估“ECM中的EVs”在体内的修复性能。植入KGN + TD@GelMA水凝胶有效地发挥了良好的骨软骨修复作用，显示出与天然组织相似的结构，并防止软骨细胞肥大。该研究表明，“ECM中的EVs”模拟系统可作为骨软骨缺损再生的高效有力支架。
