Decoupling electro-priming from implantation enables functional hyaline chondrogenesis

The regeneration of articular cartilage is challenged by local avascularity and mechanically inferior neo-fibrocartilagenesis. While electrical stimulations promote chondrogenesis, their therapeutic application is limited by signal delivery issues and cytotoxicity. Conductive polymer hydrogels, though beneficial, cause inflammation and mechanical mismatch due to non-degradability. Herein, we reported an innovative strategy for the hyaline cartilagenesis of mesenchymal stem cells (MSCs) within a conductive Gelatin methacryloyl/Polydopamine-Polyaniline-Graphene Oxide (GelMA/PDA-PAni-GO) hydrogel under programmed electrical stimulation (PES). The electro-primed MSCs were harvested and re-encapsulated into a non-conductive, benign GelMA hydrogel for implantation. This approach decoupled the programmed ES phase from the implantation phase. In a rat articular cartilage defect model, re-encapsulated PES-MSCs generated hyaline neocartilage with a native-like mechanical property and significantly enhanced defect repair outcomes compared to those in permanent GelMA/PDA-PAni-GO hydrogel, as supported by finite element analysis. Collectively, this study establishes a novel paradigm of “electro-priming and benign implantation” for achieving functional hyaline cartilage regeneration, offering a clinically viable pathway to synergize biophysical cues and stem cell therapy.