Identification of Endogenous Migratory MSC-like cells and Their Interaction with the Implant Materials Guiding Osteochondral Defect Repair
In this work, spindle-shaped cells derived from bone marrow were separated from the regenerated tissue of osteochondral defect in the SD rat model. Because these cells revealed similar features with MSCs as studied by cells morphological observation, H&E staining of regenerated tissue, typical MSCs surface markers, and differentiation potential assays in osteogenesis, adipogenesis, and chondrogenesis, so they were defined as MSC-like cells. To investigate the effects of biomaterials on MSC-like cells migration, differentiation, and osteochondral regeneration, bioinert agarose and bioactive collagen I hydrogels were filled in osteochondral defects, and evaluated by histologic staining, IHC staining and micro-CT after one month’s surgery. These results indicated that the bioinert agarose significantly inhibited cell migration and tissue regeneration, while bioactive collagen I hydrogel was found to have the therapeutic effect. It would be tempting to speculate that the specific designed scaffolds that facilitated cells migration were more propitious to osteochondral defect healing. MSC-like cells migrating into osteochondral defect had produced promising outcomes and showed therapeutic potency. In the future, additional work will focus on elucidating the sophisticated mechanisms underlying the MSC-like cells origin, function and consequences of cells migration to break through the treatment of osteochondral defect.