Fig. 1: 3D printed hydrogel scaffold with NSs enhances in vitro expansion and osteogenic potential of MSCs.

a Schematic diagram of NSs-loaded 3D printing gel scaffold by DLP technology. b Bright field image of MSCs distribution and cell morphology on the surface and inside of the gel scaffold and NSs-loaded gel scaffold for 3 days and 7 days, bar = 200 μm. c Live/Dead staining (Green, live cells; Red, dead cells) of MSCs expanded on gel scaffold and NSs-loaded gel scaffold for 7 days and 14 days, bar = 50 μm. d Bright field image and Live/Dead staining (bar = 200 μm, 50μm); e Gross view and f ALP staining, bar = 100μm, Exact p value calculated with unpaired t-test: ***p = 0.0003, n = 5 biologically independent samples; g immunostaining of RUNX2 and OCN after 7 days’ osteogenic differentiation of expanded MSCs on gel scaffold after 7 days (bar = 30 μm). h Bright field image and Live/Dead staining (bar = 200 μm, 50 μm); i Gross view and j Alizarin Red S staining, bar = 100 μm, Exact p value calculated with unpaired t-test: ***p = 0.0004, n = 4 biologically independent samples; k immunostaining of RUNX2 and OCN after 14 days’ osteogenic differentiation of expanded MSCs on gel scaffold after 7 days (bar = 30 μm). Bone marrow stem cells are isolated from orthopedic individuals with written informed consent. All data represent mean ± SEM, and source data are provided as a Source Data file. At least three times of experiments were repeated independently.