Electromagnetic field-mediated chitosan/gelatin/nano-hydroxyapatite and bone-derived scaffolds regulate the osteoblastic and chondrogenic phenotypes of adipose-derived stem cells to construct osteochondral tissue engineering niche in vitro

It is critical to explore the effects of electromagnetic field (EMF) on the construction of functional osteochondral tissue, which has shown certain clinical significance for the treatment of osteochondral injury. At present, there are few studies on the effect of the direction of EMF on cells. This study aimed to investigate the effects of EMF coupling on different parameters to control adipose-derived stem cells (ADSCs) proliferation and specific chondrogenic and osteogenic differentiation at 2D level and 3D level. The proliferation and differentiation of EMF-induced ADSCs are jointly regulated by EMF and space structure. In this study, Cs7/Gel3/nHAP scaffolds were prepared with good degradation rate (86.75 ± 4.96 %) and absorb water (1100 %), and the pore size was 195.63 ± 54.72 μm. The bone-derived scaffold with a pore size of 267.17 ± 129.18 μm was obtained and its main component was hydroxyapatite. Cs7/Gel3/nHAP scaffolds and bone-derived scaffolds are suitable as 3D level materials. The optimal EMF intensity was 2 mT for chondrogenic differentiation and proliferation and 1 mT for osteogenic differentiation and proliferation. It is noteworthy that EMF has a negative correlation with ADSCs proliferation in the vertical direction at 2D level, while it has a positive correlation with ADSCs proliferation at 3D level. EMF mediated 3D osteochondral scaffold provide good strategy for osteochondral tissue engineering construction.