Engineered hsa-miR-455-3p-Abundant Extracellular Vesicles Derived from Three-Dimensional-Cultured Adipose Mesenchymal Stem Cells for Tissue-engineering Hyaline Cartilage Regeneration.

Efforts are made to enhance the inherent potential of extracellular vesicles (EVs) by utilizing three-dimensional (3D) culture platforms and engineered strategies for functional cargo-loading. We successfully isolate three distinct types of adipose mesenchymal stem cells-derived EVs (ADSCs-EVs) utilizing 3D culture platforms consisting of porous gelatin methacryloyl (PG), PG combined with sericin methacryloyl (PG/SerMA), or PG combined with chondroitin sulfate methacryloyl (PG/ChSMA). These correspond to PG-EVs, PG/SerMA-EVs, and PG/ChSMA-EVs, respectively. We observe unique miRNA profiles in each type of ADSCs-EVs. Notably, PG-EVs encapsulate higher levels of hsa-miR-455-3p and deliver more hsa-miR-455-3p to chondrocytes, which results in the activation of the hsa-miR-455-3p/PAK2/Smad2/3 axis and the subsequent hyaline cartilage regeneration. Furthermore, we optimize the functionality of PG-EVs through engineered strategies, including agomir/lentivirus transfection, electroporation, and Exo-Fect transfection. These strategies, referred to as Agomir-EVs, Lentivirus-EVs, Electroporation-EVs, and Exo-Fect-EVs, respectively, are ranked based on their efficacy in encapsulating hsa-miR-455-3p, delivering hsa-miR-455-3p to chondrocytes, and promoting cartilage formation via the hsa-miR-455-3p/PAK2/Smad2/3 axis. Notably, Exo-Fect-EVs exhibit the highest efficiency. Collectively, the 3D culture conditions and engineered strategies have an impact on the miRNA profiles and cartilage regeneration capabilities of ADSCs-EVs. Our findings provide valuable insights into the mechanisms underlying the promotion of cartilage regeneration by ADSCs-EVs. This article is protected by copyright. All rights reserved.