Abstract
Mesenchymal stem cells (MSC) are particularly effective in promoting cartilage regeneration due to their immunomodulatory, anti-inflammatory and regenerative repair functions of tissues and organs. Meanwhile, the intra-articular delivery and synergy with other therapeutic drugs have been the key issues driving their further application. We report a mussel-inspired multifunctional hydrogel system, which could achieve co-delivery and synergism effect of MSC-derived exosomes (Exos) with icariin (ICA). The ICA and Exos co-delivered articular cavity injection system are expected to retain in the joint cavity and promote cartilage regeneration, due to the thermosensitive, self-healing and adhesion properties of the mussel-inspired multifunctional hydrogel. The experimental results proved that Exos enhanced the cellular uptake of ICA by more than 2-fold evenly, and the synergism of Exos and ICA efficiently improve the cell proliferation and migration. After synergic treatment, the content of matrix metalloproteinase 13 in the supernatant and intracellular decreased by 47% and 59%, respectively. In vivo study, ICA-loaded Exos exhibited prolonged retention behavior by multifunctional hydrogel delivery, thus displayed an increased cartilage protection. In the model of osteoarthritis, co-delivery hydrogel system relieved the cartilage recession, ensuring appropriate cartilage thickness.