Spatiotemporal regulation of endogenous MSCs using a functional injectable hydrogel system for cartilage regeneration

Abstract Hydrogels have been extensively favored as drug and cell carriers for the repair of knee cartilage defects. Recruiting mesenchymal stem cells (MSCs) in situ to defect region could reduce risk contamination during delivery, which is a highly promising strategy enhance repair. Here, cell-free tissue engineering (TE) system was developed by applying an injectable chitosan/silk fibroin hydrogel. The hydrogel release first stromal cell-derived factor-1 (SDF-1) then kartogenin (KGN) unique sequential mode, spatiotemporally promote recruitment chondrogenic differentiation MSCs. This showed good performance when formulated with SDF-1 (200 ng/mL) PLGA microspheres loaded KGN (10 μΜ). results that had injectability reticular porous structure. were distributed uniformly permitted KGN. vitro experiments cytocompatibility promoted migration MSCs into chondrocytes. In vivo on articular defects rabbits beneficial regeneration. Therefore, composite shows potential application TE.