Hydrogel-Hydroxyapatite-Monomeric Collagen Type-I Scaffold with Low-Frequency Electromagnetic field Treatment Enhances Osteochondral Repair in Rabbits

Abstract Background: Cartilage damage is a common medical issue in clinical practice. Complete cartilage repair remains a significant challenge owing to the inferior quality of regenerative tissue. Methods: In this study, a composite scaffold made of Hydroxyapatite-Collagen type-I (HAC) and PLGA-PEG-PLGA thermogel was produced to match the cartilage and subchondral layers in osteochondral defects, respectively. Bone marrow mesenchymal stem cells (BMSC) encapsulated in the thermogel were stimulated by an electromagnetic field (EMF). Results: The scaffold was evaluated in rabbits, and biological characteristic of BMSCs were measured. Results showed that the scaffold with EMF enhances the repair of osteochondral defects in rabbits, and, in particular, cartilage repair. EMF could promote proliferation and chondrogenic differentiation of BMSCs partly by activating the PI3K/AKT/mTOR and Wnt1/LRP6/β-catenin pathway. Conclusion: Hydrogel-Hydroxyapatite-Monomeric Collagen type-I scaffold with low-frequency EMF treatment has the potential to enhance osteochondral repair.