Injectable Hydrogel With Msc-Evs For Cartilage Regeneration

This study aimed to develop an injectable adhesive hydrogel loaded with MSC-derived extracellular vesicles (sEVs) to achieve sustained release and enhance cartilage regeneration in osteoarthritis by modulating inflammatory and regenerative microenvironments Materials: An injectable adhesive hydrogel (ALG-CHO/HHA) was synthesized using aldehyde-modified alginate and hydrazide-modified hyaluronic acid, loaded with MSC-derived extracellular vesicles (sEVs) from human umbilical cord Wharton’s jelly (hWJMSCs). Animal Model: Male Sprague-Dawley rats (12 weeks old, 300–350 g) with surgically induced osteoarthritis (ACLT/DMM model) were used, approved by the Ethics Committee of Yi Shengyuan Gene Technology (Protocol YSY-DWLL-2023235). Study Timeline: OA was induced over 4 weeks, followed by 4 weeks of treatment (hydrogel-sEVs injected weekly) and outcomes assessed at 8 and 12 weeks post-surgery. Methods: Techniques included flow cytometry for cell characterization, TEM/NTA for sEV validation, CCK-8/EdU/TUNEL assays for proliferation/apoptosis, Western blot for inflammatory markers (IL-6, TNF-α, MMP-13), micro-CT for OA evaluation, and histology (H&E, Safranin-O, IHC) for cartilage repair analysis. Statistics: Data were analyzed by one-way ANOVA (*p < 0.05) with SPSS 19.0, and results expressed as mean ± SD (n=3 for in vitro, n=5 for in vivo). The ALG-CHO/HHA hydrogel loaded with hWJMSC-derived sEVs promoted chondrocyte proliferation, reduced inflammation and apoptosis in vitro, and achieved sustained release in vivo The hydrogel-sEVs system enables durable cartilage repair via sustained anti-inflammatory and regenerative effects by injectioning